+++ /dev/null
-// foster btree
-// 26 MAY 2013
-
-// author: karl malbrain, malbrain@cal.berkeley.edu
-
-/*
-This work, including the source code, documentation
-and related data, is placed into the public domain.
-
-The orginal author is Karl Malbrain.
-
-THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
-OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
-MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
-ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
-RESULTING FROM THE USE, MODIFICATION, OR
-REDISTRIBUTION OF THIS SOFTWARE.
-*/
-
-// Please see the project home page for documentation
-// code.google.com/p/high-concurrency-btree
-
-#define _FILE_OFFSET_BITS 64
-#define _LARGEFILE64_SOURCE
-
-#ifdef linux
-#define _GNU_SOURCE
-#endif
-
-#ifdef unix
-#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <sys/time.h>
-#include <sys/mman.h>
-#include <errno.h>
-#include <pthread.h>
-#else
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <fcntl.h>
-#include <process.h>
-#endif
-
-#include <memory.h>
-#include <string.h>
-
-typedef unsigned long long uid;
-
-#ifndef unix
-typedef unsigned long long off64_t;
-typedef unsigned short ushort;
-typedef unsigned int uint;
-#endif
-
-#define BT_ro 0x6f72 // ro
-#define BT_rw 0x7772 // rw
-
-#define BT_maxbits 24 // maximum page size in bits
-#define BT_minbits 9 // minimum page size in bits
-#define BT_minpage (1 << BT_minbits) // minimum page size
-#define BT_maxpage (1 << BT_maxbits) // maximum page size
-
-/*
-There are five lock types for each node in three independent sets:
-1. (set 1) AccessIntent: Sharable. Going to Read the node. Incompatible with NodeDelete.
-2. (set 1) NodeDelete: Exclusive. About to release the node. Incompatible with AccessIntent.
-3. (set 2) ReadLock: Sharable. Read the node. Incompatible with WriteLock.
-4. (set 2) WriteLock: Exclusive. Modify the node. Incompatible with ReadLock and other WriteLocks.
-5. (set 3) ParentLock: Exclusive. Have parent adopt/delete maximum foster child from the node.
-*/
-
-typedef enum{
- BtLockAccess,
- BtLockDelete,
- BtLockRead,
- BtLockWrite,
- BtLockParent
-}BtLock;
-
-// Define the length of the page and key pointers
-
-#define BtId 6
-
-// Page key slot definition.
-
-// If BT_maxbits is 15 or less, you can save 4 bytes
-// for each key stored by making the first two uints
-// into ushorts. You can also save 4 bytes by removing
-// the tod field from the key.
-
-// Keys are marked dead, but remain on the page until
-// it cleanup is called. The fence key (highest key) for
-// the page is always present, even after cleanup.
-
-typedef struct {
- uint off:BT_maxbits; // page offset for key start
- uint dead:1; // set for deleted key
- uint tod; // time-stamp for key
- unsigned char id[BtId]; // id associated with key
-} BtSlot;
-
-// The key structure occupies space at the upper end of
-// each page. It's a length byte followed by the value
-// bytes.
-
-typedef struct {
- unsigned char len;
- unsigned char key[1];
-} *BtKey;
-
-// The first part of an index page.
-// It is immediately followed
-// by the BtSlot array of keys.
-
-typedef struct Page {
- uint cnt; // count of keys in page
- uint act; // count of active keys
- uint min; // next key offset
- uint foster; // count of foster children
- unsigned char bits:7; // page size in bits
- unsigned char kill:1; // page is being deleted
- unsigned char lvl; // level of page
- unsigned char right[BtId]; // page number to right
-} *BtPage;
-
-// mode & definition for latch table implementation
-
-enum {
- Write = 1,
- Share = 2
-} LockMode;
-
-// latch table lock structure
-
-// mode is set for write access
-// share is count of read accessors
-// grant write lock when share == 0
-
-typedef struct {
- int mode:1;
- int share:31;
-} BtLatch;
-
-typedef struct {
- BtLatch readwr[1]; // read/write page lock
- BtLatch access[1]; // Access Intent/Page delete
- BtLatch parent[1]; // adoption of foster children
-} BtLatchSet;
-
-// The memory mapping hash table buffer manager entry
-
-typedef struct {
- unsigned long long int lru; // number of times accessed
- uid basepage; // mapped base page number
- char *map; // mapped memory pointer
- uint pin; // mapped page pin counter
- uint slot; // slot index in this array
- void *hashprev; // previous cache block for the same hash idx
- void *hashnext; // next cache block for the same hash idx
-#ifndef unix
- HANDLE hmap;
-#endif
-// array of page latch sets, one for each page in map segment
- BtLatchSet pagelatch[0];
-} BtHash;
-
-// The object structure for Btree access
-
-typedef struct {
- uint page_size; // page size
- uint page_bits; // page size in bits
- uint seg_bits; // seg size in pages in bits
- uint mode; // read-write mode
-#ifdef unix
- int idx;
-#else
- HANDLE idx;
-#endif
- uint nodecnt; // highest page cache node in use
- uint nodemax; // highest page cache node allocated
- uint hashmask; // number of pages in mmap segment
- uint hashsize; // size of Hash Table
- uint evicted; // last evicted hash slot
- ushort *cache; // hash index for memory pool
- BtLatch *latch; // latches for hash table slots
- char *nodes; // memory pool page hash nodes
-} BtMgr;
-
-typedef struct {
- BtMgr *mgr; // buffer manager for thread
- BtPage temp; // temporary frame buffer (memory mapped/file IO)
- BtPage alloc; // frame buffer for alloc page ( page 0 )
- BtPage cursor; // cached frame for start/next (never mapped)
- BtPage frame; // spare frame for the page split (never mapped)
- BtPage zero; // page frame for zeroes at end of file
- BtPage page; // current page
- uid page_no; // current page number
- uid cursor_page; // current cursor page number
- unsigned char *mem; // frame, cursor, page memory buffer
- int err; // last error
-} BtDb;
-
-typedef enum {
- BTERR_ok = 0,
- BTERR_again,
- BTERR_struct,
- BTERR_ovflw,
- BTERR_lock,
- BTERR_map,
- BTERR_wrt,
- BTERR_hash
-} BTERR;
-
-// B-Tree functions
-extern void bt_close (BtDb *bt);
-extern BtDb *bt_open (BtMgr *mgr);
-extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod);
-extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
-extern uid bt_findkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_nextkey (BtDb *bt, uint slot);
-
-// manager functions
-extern BtMgr *bt_mgr (char *name, uint mode, uint bits, uint cacheblk, uint segsize, uint hashsize);
-void bt_mgrclose (BtMgr *mgr);
-
-// Helper functions to return cursor slot values
-
-extern BtKey bt_key (BtDb *bt, uint slot);
-extern uid bt_uid (BtDb *bt, uint slot);
-extern uint bt_tod (BtDb *bt, uint slot);
-
-// BTree page number constants
-#define ALLOC_page 0
-#define ROOT_page 1
-
-// Number of levels to create in a new BTree
-
-#define MIN_lvl 2
-
-// The page is allocated from low and hi ends.
-// The key offsets and row-id's are allocated
-// from the bottom, while the text of the key
-// is allocated from the top. When the two
-// areas meet, the page is split into two.
-
-// A key consists of a length byte, two bytes of
-// index number (0 - 65534), and up to 253 bytes
-// of key value. Duplicate keys are discarded.
-// Associated with each key is a 48 bit row-id.
-
-// The b-tree root is always located at page 1.
-// The first leaf page of level zero is always
-// located on page 2.
-
-// When to root page fills, it is split in two and
-// the tree height is raised by a new root at page
-// one with two keys.
-
-// Deleted keys are marked with a dead bit until
-// page cleanup The fence key for a node is always
-// present, even after deletion and cleanup.
-
-// Groups of pages called segments from the btree are
-// cached with memory mapping. A hash table is used to keep
-// track of the cached segments. This behaviour is controlled
-// by the cache block size parameter to bt_open.
-
-// To achieve maximum concurrency one page is locked at a time
-// as the tree is traversed to find leaf key in question.
-
-// An adoption traversal leaves the parent node locked as the
-// tree is traversed to the level in quesiton.
-
-// Page 0 is dedicated to lock for new page extensions,
-// and chains empty pages together for reuse.
-
-// Empty pages are chained together through the ALLOC page and reused.
-
-// Access macros to address slot and key values from the page
-
-#define slotptr(page, slot) (((BtSlot *)(page+1)) + (slot-1))
-#define keyptr(page, slot) ((BtKey)((unsigned char*)(page) + slotptr(page, slot)->off))
-
-void bt_putid(unsigned char *dest, uid id)
-{
-int i = BtId;
-
- while( i-- )
- dest[i] = (unsigned char)id, id >>= 8;
-}
-
-uid bt_getid(unsigned char *src)
-{
-uid id = 0;
-int i;
-
- for( i = 0; i < BtId; i++ )
- id <<= 8, id |= *src++;
-
- return id;
-}
-
-void bt_mgrclose (BtMgr *mgr)
-{
-BtHash *hash;
-uint slot;
-
- // release mapped pages
-
- for( slot = 0; slot < mgr->nodemax; slot++ ) {
- hash = (BtHash *)(mgr->nodes + slot * (sizeof(BtHash) + (mgr->hashmask + 1) * sizeof(BtLatchSet)));
- if( hash->slot )
-#ifdef unix
- munmap (hash->map, (mgr->hashmask+1) << mgr->page_bits);
-#else
- {
- FlushViewOfFile(hash->map, 0);
- UnmapViewOfFile(hash->map);
- CloseHandle(hash->hmap);
- }
-#endif
- }
-
-#ifdef unix
- close (mgr->idx);
- free (mgr->nodes);
- free (mgr->cache);
- free (mgr->latch);
-#else
- FlushFileBuffers(mgr->idx);
- CloseHandle(mgr->idx);
- GlobalFree (mgr->nodes);
- GlobalFree (mgr->cache);
- GlobalFree (mgr->latch);
-#endif
-}
-
-// close and release memory
-
-void bt_close (BtDb *bt)
-{
-#ifdef unix
- if ( bt->mem )
- free (bt->mem);
- free (bt);
-#else
- if ( bt->mem)
- VirtualFree (bt->mem, 0, MEM_RELEASE);
- GlobalFree (bt);
-#endif
-}
-
-// open/create new btree buffer manager
-
-// call with file_name, BT_openmode, bits in page size (e.g. 16),
-// size of mapped page cache (e.g. 8192)
-
-BtMgr *bt_mgr (char *name, uint mode, uint bits, uint nodemax, uint segsize, uint hashsize)
-{
-uint lvl, attr, cacheblk, last;
-BtPage alloc;
-int lockmode;
-off64_t size;
-uint amt[1];
-BtMgr* mgr;
-BtKey key;
-
-#ifndef unix
-SYSTEM_INFO sysinfo[1];
-#endif
-
- // determine sanity of page size and buffer pool
-
- if( bits > BT_maxbits )
- bits = BT_maxbits;
- else if( bits < BT_minbits )
- bits = BT_minbits;
-
- if( !nodemax )
- return NULL; // must have buffer pool
-
-#ifdef unix
- mgr = calloc (1, sizeof(BtMgr));
-
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
- lockmode = 1;
- break;
-
- case BT_ro:
- default:
- mgr->idx = open ((char*)name, O_RDONLY);
- lockmode = 0;
- break;
- }
- if( mgr->idx == -1 )
- return free(mgr), NULL;
-
- cacheblk = 4096; // minimum mmap segment size for unix
-
-#else
- mgr = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtMgr));
- attr = FILE_ATTRIBUTE_NORMAL;
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
- lockmode = 1;
- break;
-
- case BT_ro:
- default:
- mgr->idx = CreateFile(name, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, attr, NULL);
- lockmode = 0;
- break;
- }
- if( mgr->idx == INVALID_HANDLE_VALUE )
- return GlobalFree(mgr), NULL;
-
- // normalize cacheblk to multiple of sysinfo->dwAllocationGranularity
- GetSystemInfo(sysinfo);
- cacheblk = sysinfo->dwAllocationGranularity;
-#endif
-
-#ifdef unix
- alloc = malloc (BT_maxpage);
- *amt = 0;
-
- // read minimum page size to get root info
-
- if( size = lseek (mgr->idx, 0L, 2) ) {
- if( pread(mgr->idx, alloc, BT_minpage, 0) == BT_minpage )
- bits = alloc->bits;
- else
- return free(mgr), free(alloc), NULL;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#else
- alloc = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
- size = GetFileSize(mgr->idx, amt);
-
- if( size || *amt ) {
- if( !ReadFile(mgr->idx, (char *)alloc, BT_minpage, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- bits = alloc->bits;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- mgr->page_size = 1 << bits;
- mgr->page_bits = bits;
-
- mgr->nodemax = nodemax;
- mgr->mode = mode;
-
- if( cacheblk < mgr->page_size )
- cacheblk = mgr->page_size;
-
- // mask for partial memmaps
-
- mgr->hashmask = (cacheblk >> bits) - 1;
-
- // see if requested number of pages per memmap is greater
-
- if( (1 << segsize) > mgr->hashmask )
- mgr->hashmask = (1 << segsize) - 1;
-
- mgr->seg_bits = 0;
-
- while( (1 << mgr->seg_bits) <= mgr->hashmask )
- mgr->seg_bits++;
-
- mgr->hashsize = hashsize;
-
-#ifdef unix
- mgr->nodes = calloc (cacheblk, (sizeof(BtHash) + (mgr->hashmask + 1) * sizeof(BtLatchSet)));
- mgr->cache = calloc (hashsize, sizeof(ushort));
- mgr->latch = calloc (hashsize, sizeof(BtLatch));
-#else
- mgr->nodes = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, cacheblk * (sizeof(BtHash) + (mgr->hashmask + 1) * sizeof(BtLatchSet)));
- mgr->cache = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(ushort));
- mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtLatch));
-#endif
-
- if( size || *amt )
- goto mgrxit;
-
- // initializes an empty b-tree with root page and page of leaves
-
- memset (alloc, 0, 1 << bits);
- bt_putid(slotptr(alloc, 2)->id, MIN_lvl+1);
- alloc->bits = mgr->page_bits;
-
-#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- memset (alloc, 0, 1 << bits);
- alloc->bits = mgr->page_bits;
-
- for( lvl=MIN_lvl; lvl--; ) {
- slotptr(alloc, 1)->off = mgr->page_size - 3;
- bt_putid(slotptr(alloc, 1)->id, lvl ? MIN_lvl - lvl + 1 : 0); // next(lower) page number
- key = keyptr(alloc, 1);
- key->len = 2; // create stopper key
- key->key[0] = 0xff;
- key->key[1] = 0xff;
- alloc->min = mgr->page_size - 3;
- alloc->lvl = lvl;
- alloc->cnt = 1;
- alloc->act = 1;
-#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
- // create empty page area by writing last page of first
- // cache area (other pages are zeroed by O/S)
-
- if( mgr->hashmask ) {
- memset(alloc, 0, mgr->page_size);
- last = mgr->hashmask;
-
- while( last < MIN_lvl + 1 )
- last += mgr->hashmask + 1;
-
-#ifdef unix
- pwrite(mgr->idx, alloc, mgr->page_size, last << mgr->page_bits);
-#else
- SetFilePointer (mgr->idx, last << mgr->page_bits, NULL, FILE_BEGIN);
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
-mgrxit:
-#ifdef unix
- free (alloc);
-#else
- VirtualFree (alloc, 0, MEM_RELEASE);
-#endif
- return mgr;
-}
-
-// open BTree access method
-// based on buffer manager
-
-BtDb *bt_open (BtMgr *mgr)
-{
-BtDb *bt = malloc (sizeof(*bt));
-
- memset (bt, 0, sizeof(*bt));
- bt->mgr = mgr;
-#ifdef unix
- bt->mem = malloc (3 *mgr->page_size);
-#else
- bt->mem = VirtualAlloc(NULL, 3 * mgr->page_size, MEM_COMMIT, PAGE_READWRITE);
-#endif
- bt->frame = (BtPage)bt->mem;
- bt->zero = (BtPage)(bt->mem + 1 * mgr->page_size);
- bt->cursor = (BtPage)(bt->mem + 2 * mgr->page_size);
- return bt;
-}
-
-// compare two keys, returning > 0, = 0, or < 0
-// as the comparison value
-
-int keycmp (BtKey key1, unsigned char *key2, uint len2)
-{
-uint len1 = key1->len;
-int ans;
-
- if( ans = memcmp (key1->key, key2, len1 > len2 ? len2 : len1) )
- return ans;
-
- if( len1 > len2 )
- return 1;
- if( len1 < len2 )
- return -1;
-
- return 0;
-}
-
-// Latch Manager
-
-// wait until write lock mode is clear
-// and add 1 to the share count
-
-void bt_readlock(BtLatch *latch)
-{
- do {
- // add one to counter, check write bit
-
-#ifdef unix
- if( ~__sync_fetch_and_add((int *)latch, Share) & Write )
- return;
-#else
- if( ~InterlockedAdd((int *)latch, Share) & Write )
- return;
-#endif
- // didn't get latch, reset counter by one
-
-#ifdef unix
- __sync_fetch_and_add((int *)latch, -Share);
-#else
- InterlockedAdd ((int *)latch, -Share);
-#endif
-
- // and yield
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- } while( 1 );
-}
-
-// wait for other read and write latches to relinquish
-
-void bt_writelock(BtLatch *latch)
-{
-int prev, ours = 0;
-
- do {
- // see if we can get write access
- // with no readers
-#ifdef unix
- prev = __sync_fetch_and_or((int *)latch, Write);
-#else
- prev = InterlockedOr((int *)latch, Write);
-#endif
-
- if( ~prev & 1 )
- ours++; // it's ours
-
- if( !(prev >> 1) && ours )
- return;
-
- // otherwise yield
-
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- } while( 1 );
-}
-
-// try to obtain write lock
-
-// return 1 if obtained,
-// 0 if already write locked
-
-int bt_writetry(BtLatch *latch)
-{
-int prev, ours = 0;
-
- do {
- // see if we can get write access
- // with no readers
-#ifdef unix
- prev = __sync_fetch_and_or((int *)latch, Write);
-#else
- prev = InterlockedOr((int *)latch, Write);
-#endif
-
- if( ~prev & 1 )
- ours++; // it's ours
-
- if( !ours )
- return 0;
-
- if( !(prev >> 1) && ours )
- return 1;
-
- // otherwise yield
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- } while( 1 );
-}
-
-// clear write mode
-
-void bt_releasewrite(BtLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_and((int *)latch, ~Write);
-#else
- InterlockedAnd ((int *)latch, ~Write);
-#endif
-}
-
-// decrement reader count
-
-void bt_releaseread(BtLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_add((int *)latch, -Share);
-#else
- InterlockedAdd((int *)latch, -Share);
-#endif
-}
-
-// Buffer Pool mgr
-
-// find segment in cache
-// return NULL if not there
-// otherwise return node
-
-BtHash *bt_findhash(BtDb *bt, uid page_no, uint idx)
-{
-BtHash *hash;
-uint slot;
-
- // compute cache block first page and hash idx
-
- if( slot = bt->mgr->cache[idx] )
- hash = (BtHash *)(bt->mgr->nodes + slot * (sizeof(BtHash) + (bt->mgr->hashmask + 1) * sizeof(BtLatchSet)));
- else
- return NULL;
-
- page_no &= ~bt->mgr->hashmask;
-
- while( hash->basepage != page_no )
- if( hash = hash->hashnext )
- continue;
- else
- return NULL;
-
- return hash;
-}
-
-// add segment to hash table
-
-void bt_linkhash(BtDb *bt, BtHash *hash, uid page_no, int idx)
-{
-BtHash *node;
-uint slot;
-
- hash->hashprev = hash->hashnext = NULL;
- hash->basepage = page_no & ~bt->mgr->hashmask;
- hash->pin = 1;
- hash->lru = 1;
-
- if( slot = bt->mgr->cache[idx] ) {
- node = (BtHash *)(bt->mgr->nodes + slot * (sizeof(BtHash) + (bt->mgr->hashmask + 1) * sizeof(BtLatchSet)));
- hash->hashnext = node;
- node->hashprev = hash;
- }
-
- bt->mgr->cache[idx] = hash->slot;
-}
-
-// find best segment to evict from buffer pool
-
-BtHash *bt_findlru (BtDb *bt, uint slot)
-{
-unsigned long long int target = ~0LL;
-BtHash *hash = NULL, *node;
-
- if( !slot )
- return NULL;
-
- node = (BtHash *)(bt->mgr->nodes + slot * (sizeof(BtHash) + (bt->mgr->hashmask + 1) * sizeof(BtLatchSet)));
-
- do {
- if( node->pin )
- continue;
- if( node->lru > target )
- continue;
- target = node->lru;
- hash = node;
- } while( node = node->hashnext );
-
- return hash;
-}
-
-// map new segment to virtual memory
-
-BTERR bt_mapsegment(BtDb *bt, BtHash *hash, uid page_no)
-{
-off64_t off = (page_no & ~bt->mgr->hashmask) << bt->mgr->page_bits;
-off64_t limit = off + ((bt->mgr->hashmask+1) << bt->mgr->page_bits);
-int flag;
-
-#ifdef unix
- flag = PROT_READ | ( bt->mgr->mode == BT_ro ? 0 : PROT_WRITE );
- hash->map = mmap (0, (bt->mgr->hashmask+1) << bt->mgr->page_bits, flag, MAP_SHARED, bt->mgr->idx, off);
- if( hash->map == MAP_FAILED )
- return bt->err = BTERR_map;
-#else
- flag = ( bt->mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
- hash->hmap = CreateFileMapping(bt->mgr->idx, NULL, flag, (DWORD)(limit >> 32), (DWORD)limit, NULL);
- if( !hash->hmap )
- return bt->err = BTERR_map;
-
- flag = ( bt->mgr->mode == BT_ro ? FILE_MAP_READ : FILE_MAP_WRITE );
- hash->map = MapViewOfFile(hash->hmap, flag, (DWORD)(off >> 32), (DWORD)off, (bt->mgr->hashmask+1) << bt->mgr->page_bits);
- if( !hash->map )
- return bt->err = BTERR_map;
-#endif
- return bt->err = 0;
-}
-
-// find or place requested page in segment-cache
-// return hash table entry
-
-BtHash *bt_hashpage(BtDb *bt, uid page_no)
-{
-BtHash *hash, *node, *next;
-uint slot, idx, victim;
-BtLatchSet *set;
-
- // lock hash table chain
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx]);
-
- // look up in hash table
-
- if( hash = bt_findhash(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&hash->pin, 1);
-#else
- InterlockedIncrement (&hash->pin);
-#endif
- bt_releaseread (&bt->mgr->latch[idx]);
- hash->lru++;
- return hash;
- }
-
- // upgrade to write lock
-
- bt_releaseread (&bt->mgr->latch[idx]);
- bt_writelock (&bt->mgr->latch[idx]);
-
- // try to find page in cache with write lock
-
- if( hash = bt_findhash(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&hash->pin, 1);
-#else
- InterlockedIncrement (&hash->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx]);
- hash->lru++;
- return hash;
- }
-
- // allocate a new hash node
- // and add to hash table
-
-#ifdef unix
- slot = __sync_fetch_and_add(&bt->mgr->nodecnt, 1);
-#else
- slot = InterlockedIncrement (&bt->mgr->nodecnt) - 1;
-#endif
-
- if( ++slot < bt->mgr->nodemax ) {
- hash = (BtHash *)(bt->mgr->nodes + slot * (sizeof(BtHash) + (bt->mgr->hashmask + 1) * sizeof(BtLatchSet)));
- hash->slot = slot;
-
- if( bt_mapsegment(bt, hash, page_no) )
- return NULL;
-
- bt_linkhash(bt, hash, page_no, idx);
- bt_releasewrite (&bt->mgr->latch[idx]);
- return hash;
- }
-
- // hash table is full
- // find best cache entry to evict
-
-#ifdef unix
- __sync_fetch_and_add(&bt->mgr->nodecnt, -1);
-#else
- InterlockedDecrement (&bt->mgr->nodecnt);
-#endif
-
- while( 1 ) {
-#ifdef unix
- victim = __sync_fetch_and_add(&bt->mgr->evicted, 1);
-#else
- victim = InterlockedIncrement (&bt->mgr->evicted) - 1;
-#endif
- victim %= bt->mgr->hashsize;
-
- // try to get write lock
- // skip entry if not obtained
-
- if( !bt_writetry (&bt->mgr->latch[victim]) )
- continue;
-
- // if cache entry is empty
- // or no slots are unpinned
- // skip this entry
-
- if( !(hash = bt_findlru(bt, bt->mgr->cache[victim])) ) {
- bt_releasewrite (&bt->mgr->latch[victim]);
- continue;
- }
-
- // unlink victim hash node from hash table
-
- if( node = hash->hashprev )
- node->hashnext = hash->hashnext;
- else if( node = hash->hashnext )
- bt->mgr->cache[victim] = node->slot;
- else
- bt->mgr->cache[victim] = 0;
-
- if( node = hash->hashnext )
- node->hashprev = hash->hashprev;
-
- // remove old file mapping
-#ifdef unix
- munmap (hash->map, (bt->mgr->hashmask+1) << bt->mgr->page_bits);
-#else
- FlushViewOfFile(hash->map, 0);
- UnmapViewOfFile(hash->map);
- CloseHandle(hash->hmap);
-#endif
- hash->map = NULL;
- bt_releasewrite (&bt->mgr->latch[victim]);
-
- // create new file mapping
- // and link into hash table
-
- if( bt_mapsegment(bt, hash, page_no) )
- return NULL;
-
- bt_linkhash(bt, hash, page_no, idx);
- bt_releasewrite (&bt->mgr->latch[idx]);
- return hash;
- }
-}
-
-// place write, read, or parent lock on requested page_no.
-// pin to buffer pool
-
-BTERR bt_lockpage(BtDb *bt, uid page_no, BtLock mode, BtPage *page)
-{
-BtLatchSet *set;
-BtHash *hash;
-uint subpage;
-
- // find/create maping in hash table
-
- if( hash = bt_hashpage(bt, page_no) )
- subpage = (uint)(page_no & bt->mgr->hashmask); // page within mapping
- else
- return bt->err;
-
- set = hash->pagelatch + subpage;
-
- switch( mode ) {
- case BtLockRead:
- bt_readlock (set->readwr);
- break;
- case BtLockWrite:
- bt_writelock (set->readwr);
- break;
- case BtLockAccess:
- bt_readlock (set->access);
- break;
- case BtLockDelete:
- bt_writelock (set->access);
- break;
- case BtLockParent:
- bt_writelock (set->parent);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
- if( page )
- *page = (BtPage)(hash->map + (subpage << bt->mgr->page_bits));
-
- return bt->err = 0;
-}
-
-// remove write, read, or parent lock on requested page_no.
-
-BTERR bt_unlockpage(BtDb *bt, uid page_no, BtLock mode)
-{
-uint subpage, idx;
-BtLatchSet *set;
-BtHash *hash;
-
- // since page is pinned
- // it should still be in the buffer pool
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx]);
-
- if( hash = bt_findhash(bt, page_no, idx) )
- subpage = (uint)(page_no & bt->mgr->hashmask);
- else
- return bt->err = BTERR_hash;
-
- bt_releaseread (&bt->mgr->latch[idx]);
- set = hash->pagelatch + subpage;
-
- switch( mode ) {
- case BtLockRead:
- bt_releaseread (set->readwr);
- break;
- case BtLockWrite:
- bt_releasewrite (set->readwr);
- break;
- case BtLockAccess:
- bt_releaseread (set->access);
- break;
- case BtLockDelete:
- bt_releasewrite (set->access);
- break;
- case BtLockParent:
- bt_releasewrite (set->parent);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
-#ifdef unix
- __sync_fetch_and_add(&hash->pin, -1);
-#else
- InterlockedDecrement (&hash->pin);
-#endif
- return bt->err = 0;
-}
-
-// deallocate a deleted page that has no tree pointers
-// place on free chain out of allocator page
-
-BTERR bt_freepage(BtDb *bt, uid page_no)
-{
- // obtain delete lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- // obtain write lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // lock allocation page
-
- if ( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return bt->err;
-
- // store chain in first key
- bt_putid(slotptr(bt->temp, 1)->id, bt_getid(slotptr(bt->alloc, 1)->id));
- bt_putid(slotptr(bt->alloc, 1)->id, page_no);
-
- // unlock page zero
-
- if( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return bt->err;
-
- // remove write lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // remove delete lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockDelete) )
- return bt->err;
-
- return 0;
-}
-
-// allocate a new page and write page into it
-
-uid bt_newpage(BtDb *bt, BtPage page)
-{
-uid new_page;
-BtPage pmap;
-int reuse;
-
- // lock page zero
-
- if ( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return 0;
-
- // use empty chain first
- // else allocate empty page
-
- if( new_page = bt_getid(slotptr(bt->alloc, 1)->id) ) {
- if( bt_lockpage (bt, new_page, BtLockWrite, &bt->temp) )
- return 0;
- bt_putid(slotptr(bt->alloc, 1)->id, bt_getid(slotptr(bt->temp, 1)->id));
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
- reuse = 1;
- } else {
- new_page = bt_getid(slotptr(bt->alloc, 2)->id);
- bt_putid(slotptr(bt->alloc, 2)->id, new_page+1);
- reuse = 0;
- }
-#ifdef unix
- if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
-
- // if writing first page of hash block, zero last page in the block
-
- if ( !reuse && bt->mgr->hashmask > 0 && (new_page & bt->mgr->hashmask) == 0 )
- {
- // use zero buffer to write zeros
- memset(bt->zero, 0, bt->mgr->page_size);
- if ( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->hashmask) << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
- }
-#else
- // bring new page into page-cache and copy page.
- // this will extend the file into the new pages.
-
- if( bt_lockpage(bt, new_page, BtLockWrite, &pmap) )
- return 0;
-
- memcpy(pmap, page, bt->mgr->page_size);
-
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
-#endif
- // unlock page zero
-
- if ( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return 0;
-
- return new_page;
-}
-
-// find slot in page for given key at a given level
-
-int bt_findslot (BtDb *bt, unsigned char *key, uint len)
-{
-uint diff, higher = bt->page->cnt, low = 1, slot;
-
- // low is the lowest candidate, higher is already
- // tested as .ge. the given key, loop ends when they meet
-
- while( diff = higher - low ) {
- slot = low + ( diff >> 1 );
- if( keycmp (keyptr(bt->page, slot), key, len) < 0 )
- low = slot + 1;
- else
- higher = slot;
- }
-
- return higher;
-}
-
-// find and load page at given level for given key
-// leave page rd or wr locked as requested
-
-int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, uint lock)
-{
-uid page_no = ROOT_page, prevpage = 0;
-uint drill = 0xff, slot;
-uint mode, prevmode;
-
- // start at root of btree and drill down
-
- do {
- // determine lock mode of drill level
- mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead;
-
- bt->page_no = page_no;
-
- // obtain access lock using lock chaining with Access mode
-
- if( page_no > ROOT_page )
- if( bt_lockpage(bt, page_no, BtLockAccess, NULL) )
- return 0;
-
- if( prevpage )
- if( bt_unlockpage(bt, prevpage, prevmode) )
- return 0;
-
- // obtain read lock using lock chaining
- // and pin page contents
-
- if( bt_lockpage(bt, page_no, mode, &bt->page) )
- return 0;
-
- if( page_no > ROOT_page )
- if( bt_unlockpage(bt, page_no, BtLockAccess) )
- return 0;
-
- // re-read and re-lock root after determining actual level of root
-
- if( bt->page_no == ROOT_page )
- if( bt->page->lvl != drill) {
- drill = bt->page->lvl;
-
- if( lock == BtLockWrite && drill == lvl )
- if( bt_unlockpage(bt, page_no, mode) )
- return 0;
- else
- continue;
- }
-
- // if page is being deleted,
- // move back to preceeding page
-
- if( bt->page->kill ) {
- page_no = bt_getid (bt->page->right);
- continue;
- }
-
- // find key on page at this level
- // and descend to requested level
-
- slot = bt_findslot (bt, key, len);
-
- // is this slot a foster child?
-
- if( slot <= bt->page->cnt - bt->page->foster )
- if( drill == lvl )
- return slot;
- else
- drill--;
-
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
- continue;
- else
- return bt->err = BTERR_struct, 0;
-
- // continue down / right using overlapping locks
- // to protect pages being killed or split.
-
- prevmode = mode;
- prevpage = bt->page_no;
- page_no = bt_getid(slotptr(bt->page, slot)->id);
- } while( page_no );
-
- // return error on end of chain
-
- bt->err = BTERR_struct;
- return 0; // return error
-}
-
-// find and delete key on page by marking delete flag bit
-// when page becomes empty, delete it from the btree
-
-BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl)
-{
-unsigned char leftkey[256], rightkey[256];
-uid page_no, right;
-uint slot, tod;
-BtKey ptr;
-
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // if key is found delete it, otherwise ignore request
-
- if( !keycmp (ptr, key, len) )
- if( slotptr(bt->page, slot)->dead == 0 )
- slotptr(bt->page,slot)->dead = 1, bt->page->act--;
-
- // return if page is not empty, or it has no right sibling
-
- right = bt_getid(bt->page->right);
- page_no = bt->page_no;
-
- if( !right || bt->page->act )
- return bt_unlockpage(bt, page_no, BtLockWrite);
-
- // obtain Parent lock over write lock
-
- if( bt_lockpage(bt, page_no, BtLockParent, NULL) )
- return bt->err;
-
- // cache copy of key to delete
-
- ptr = keyptr(bt->page, bt->page->cnt);
- memcpy(leftkey, ptr, ptr->len + 1);
-
- // lock and map right page
-
- if ( bt_lockpage(bt, right, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // pull contents of next page into current empty page
- memcpy (bt->page, bt->temp, bt->mgr->page_size);
-
- // cache copy of key to update
- ptr = keyptr(bt->temp, bt->temp->cnt);
- memcpy(rightkey, ptr, ptr->len + 1);
-
- // Mark right page as deleted and point it to left page
- // until we can post updates at higher level.
-
- bt_putid(bt->temp->right, page_no);
- bt->temp->kill = 1;
- bt->temp->cnt = 0;
-
- if( bt_unlockpage(bt, right, BtLockWrite) )
- return bt->err;
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // delete old lower key to consolidated node
-
- if( bt_deletekey (bt, leftkey + 1, *leftkey, lvl + 1) )
- return bt->err;
-
- // redirect higher key directly to consolidated node
-
- if( slot = bt_loadpage (bt, rightkey+1, *rightkey, lvl+1, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // since key already exists, update id
-
- if( keycmp (ptr, rightkey+1, *rightkey) )
- return bt->err = BTERR_struct;
-
- slotptr(bt->page, slot)->dead = 0;
- bt_putid(slotptr(bt->page,slot)->id, page_no);
- bt_unlockpage(bt, bt->page_no, BtLockWrite);
-
- // obtain write lock and
- // add right block to free chain
-
- if( bt_freepage (bt, right) )
- return bt->err;
-
- // remove ParentModify lock
-
- if( bt_unlockpage(bt, page_no, BtLockParent) )
- return bt->err;
-
- return 0;
-}
-
-// find key in leaf level and return row-id
-
-uid bt_findkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-BtKey ptr;
-uid id;
-
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- ptr = keyptr(bt->page, slot);
- else
- return 0;
-
- // if key exists, return row-id
- // otherwise return 0
-
- if( ptr->len == len && !memcmp (ptr->key, key, len) )
- id = bt_getid(slotptr(bt->page,slot)->id);
- else
- id = 0;
-
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
-
- return id;
-}
-
-void bt_cleanpage(BtDb *bt)
-{
-uint nxt = bt->mgr->page_size;
-BtPage page = bt->page;
-uint cnt = 0, idx = 0;
-uint max = page->cnt;
-BtKey key;
-
- memcpy (bt->frame, page, bt->mgr->page_size);
-
- // skip page info and set rest of page to zero
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- page->act = 0;
-
- // try cleaning up page first
-
- while( cnt++ < max ) {
- // always leave fence key in list
- if( cnt < max && slotptr(bt->frame,cnt)->dead )
- continue;
-
- // copy key
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
-
- // copy slot
- memcpy(slotptr(page, ++idx)->id, slotptr(bt->frame, cnt)->id, BtId);
- if( !(slotptr(page, idx)->dead = slotptr(bt->frame, cnt)->dead) )
- page->act++;
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- }
- page->min = nxt;
- page->cnt = idx;
-}
-
-// add key to page
-// return with page unlocked
-
-BTERR bt_addkeytopage (BtDb *bt, uint slot, unsigned char *key, uint len, uid id, uint tod)
-{
-BtPage page = bt->page;
-uint idx;
-
- // calculate next available slot and copy key into page
-
- page->min -= len + 1;
- ((unsigned char *)page)[page->min] = len;
- memcpy ((unsigned char *)page + page->min +1, key, len );
-
- for( idx = slot; idx < page->cnt; idx++ )
- if( slotptr(page, idx)->dead )
- break;
-
- // now insert key into array before slot
- // preserving the fence slot
-
- if( idx == page->cnt )
- idx++, page->cnt++;
-
- page->act++;
-
- while( idx > slot )
- *slotptr(page, idx) = *slotptr(page, idx -1), idx--;
-
- bt_putid(slotptr(page,slot)->id, id);
- slotptr(page, slot)->off = page->min;
- slotptr(page, slot)->tod = tod;
- slotptr(page, slot)->dead = 0;
-
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
-}
-
-// split the root and raise the height of the btree
-
-BTERR bt_splitroot(BtDb *bt, uid right)
-{
-uint nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-BtPage root = bt->page;
-uid new_page;
-BtKey key;
-
- // Obtain an empty page to use, and copy the left page
- // contents into it. Strip foster child key.
- // Save left fence key.
-
- bt->page->act--;
- bt->page->cnt--;
- bt->page->foster--;
- key = keyptr(bt->page, bt->page->cnt);
- memcpy (fencekey, key, key->len + 1);
-
- if( !(new_page = bt_newpage(bt, bt->page)) )
- return bt->err;
-
- // preserve the page info at the bottom
- // and set rest to zero
-
- memset (root+1, 0, bt->mgr->page_size - sizeof(*root));
-
- // insert left fence key on newroot page
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 1)->id, new_page);
- slotptr(root, 1)->off = nxt;
-
- // insert stopper key on newroot page
- // and increase the root height
-
- nxt -= 3;
- fencekey[0] = 2;
- fencekey[1] = 0xff;
- fencekey[2] = 0xff;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 2)->id, right);
- slotptr(root, 2)->off = nxt;
-
- bt_putid(root->right, 0);
- root->min = nxt; // reset lowest used offset and key count
- root->cnt = 2;
- root->act = 2;
- root->lvl++;
-
- // release root (bt->page)
-
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
-}
-
-// split already locked full node
-// return unlocked.
-
-BTERR bt_splitpage (BtDb *bt, uint len)
-{
-uint slot, cnt, idx, max, nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-uid page_no = bt->page_no;
-BtPage page = bt->page;
-uint tod = time(NULL);
-uint lvl = page->lvl;
-uid new_page, right;
-BtKey key;
-
- // perform cleanup
-
- bt_cleanpage(bt);
-
- // return if enough space now
-
- if( page->min >= (page->cnt + 1) * sizeof(BtSlot) + sizeof(*page) + len + 1)
- return bt_unlockpage(bt, page_no, BtLockWrite);
-
- // initialize frame buffer
-
- memset (bt->frame, 0, bt->mgr->page_size);
- max = page->cnt - page->foster;
- tod = (uint)time(NULL);
- cnt = max / 2;
- idx = 0;
-
- // split higher half of keys to bt->frame
- // leaving foster children in the left node.
-
- while( cnt++ < max ) {
- key = keyptr(page, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)bt->frame + nxt, key, key->len + 1);
- memcpy(slotptr(bt->frame,++idx)->id, slotptr(page,cnt)->id, BtId);
- slotptr(bt->frame, idx)->tod = slotptr(page, cnt)->tod;
- slotptr(bt->frame, idx)->off = nxt;
- bt->frame->act++;
- }
-
- // transfer right link node
-
- if( page_no > ROOT_page ) {
- right = bt_getid (page->right);
- bt_putid(bt->frame->right, right);
- }
-
- bt->frame->bits = bt->mgr->page_bits;
- bt->frame->min = nxt;
- bt->frame->cnt = idx;
- bt->frame->lvl = lvl;
-
- // get new free page and write frame to it.
-
- if( !(new_page = bt_newpage(bt, bt->frame)) )
- return bt->err;
-
- // update lower keys and foster children to continue in old page
-
- memcpy (bt->frame, page, bt->mgr->page_size);
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- nxt = bt->mgr->page_size;
- page->act = 0;
- cnt = 0;
- idx = 0;
-
- // assemble page of smaller keys
- // to remain in the old page
-
- while( cnt++ < max / 2 ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- // assemble old foster child keys
- // add new foster child fence
-
- cnt = bt->frame->cnt - bt->frame->foster - 1;
-
- while( cnt++ < bt->frame->cnt ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- // link new right page
-
- bt_putid (page->right, new_page);
-
- // put new page as smallest foster child key
-
- page->cnt = idx;
- cnt = page->cnt - page->foster++;
- bt_putid (slotptr(page,cnt)->id, new_page);
-
- // if current page is the root page, split it
-
- if( page_no == ROOT_page )
- return bt_splitroot (bt, new_page);
-
- // release wr lock on page
-
- if( bt_unlockpage (bt, page_no, BtLockWrite) )
- return bt->err;
-
- // obtain ParentModification lock for current page
- // to fix highest foster child on page
-
- if( bt_lockpage (bt, page_no, BtLockParent, NULL) )
- return bt->err;
-
- if( bt_lockpage (bt, page_no, BtLockRead, &page) )
- return bt->err;
-
- // get our old fence key
-
- key = keyptr(page, page->cnt);
- memcpy (fencekey, key, key->len+1);
-
- // get our new fence key length
-
- key = keyptr(page, page->cnt - 1);
- len = key->len;
-
- if( bt_unlockpage (bt, page_no, BtLockRead) )
- return bt->err;
-
- do {
- slot = bt_loadpage (bt, fencekey + 1, *fencekey, lvl + 1, BtLockWrite);
-
- if( !slot )
- return bt->err;
-
- // check if parent page has enough space
-
- if( bt->page->min < (bt->page->cnt + 1) * sizeof(BtSlot) + sizeof(*bt->page) + len + 1)
- if( bt_splitpage (bt, len) )
- return bt->err;
- else
- continue;
- else
- break;
- } while( 1 );
-
- // wait for readers from parent get their locks
-
- if( bt_lockpage (bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- if( bt_lockpage (bt, page_no, BtLockWrite, &page) )
- return bt->err;
-
- // switch parent fence key to foster child
-
- if( slotptr(page, page->cnt)->dead )
- slotptr(bt->page, slot)->dead = 1;
- else
- bt_putid (slotptr(bt->page, slot)->id, bt_getid(slotptr(page, page->cnt)->id));
-
- // remove foster child from our page
- // add our new fence key to parent
-
- page->cnt--;
- page->act--;
- page->foster--;
- key = keyptr(page, page->cnt);
-
- if( bt_addkeytopage (bt, slot, key->key, key->len, page_no, tod) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockDelete) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockParent) )
- return bt->err;
-
- return bt_unlockpage (bt, page_no, BtLockWrite);
-}
-
-// Insert new key into the btree at leaf level.
-
-BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod)
-{
-uint slot, idx;
-BtPage page;
-BtKey ptr;
-
- while( 1 ) {
- if( slot = bt_loadpage (bt, key, len, 0, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- {
- if ( !bt->err )
- bt->err = BTERR_ovflw;
- return bt->err;
- }
-
- // if key already exists, update id and return
-
- page = bt->page;
-
- if( !keycmp (ptr, key, len) ) {
- slotptr(page, slot)->dead = 0;
- slotptr(page, slot)->tod = tod;
- bt_putid(slotptr(page,slot)->id, id);
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
- }
-
- // check if page has enough space
-
- if( page->min >= (page->cnt + 1) * sizeof(BtSlot) + sizeof(*page) + len + 1)
- break;
-
- if( bt_splitpage (bt, len) )
- return bt->err;
- }
-
- return bt_addkeytopage (bt, slot, key, len, id, tod);
-}
-
-// cache page of keys into cursor and return starting slot for given key
-
-uint bt_startkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-
- // cache page for retrieval
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- memcpy (bt->cursor, bt->page, bt->mgr->page_size);
- bt->cursor_page = bt->page_no;
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
-
- return slot;
-}
-
-// return next slot for cursor page
-// or slide cursor right into next page
-
-uint bt_nextkey (BtDb *bt, uint slot)
-{
-BtPage page;
-uid right;
-
- do {
- right = bt_getid(bt->cursor->right);
- while( slot++ < bt->cursor->cnt - bt->cursor->foster )
- if( slotptr(bt->cursor,slot)->dead )
- continue;
- else if( right || (slot < bt->cursor->cnt - bt->cursor->foster) )
- return slot;
- else
- break;
-
- if( !right )
- break;
-
- bt->cursor_page = right;
-
- if( bt_lockpage(bt, right, BtLockRead, &page) )
- return 0;
-
- memcpy (bt->cursor, page, bt->mgr->page_size);
-
- if ( bt_unlockpage(bt, right, BtLockRead) )
- return 0;
-
- slot = 0;
- } while( 1 );
-
- return bt->err = 0;
-}
-
-BtKey bt_key(BtDb *bt, uint slot)
-{
- return keyptr(bt->cursor, slot);
-}
-
-uid bt_uid(BtDb *bt, uint slot)
-{
- return bt_getid(slotptr(bt->cursor,slot)->id);
-}
-
-uint bt_tod(BtDb *bt, uint slot)
-{
- return slotptr(bt->cursor,slot)->tod;
-}
-
-
-#ifdef STANDALONE
-
-typedef struct {
- char *infile;
- char type;
- BtMgr *mgr;
-} ThreadArg;
-
-// standalone program to index file of keys
-// then list them onto std-out
-
-#ifdef unix
-void *index_file (void *arg)
-#else
-uint __stdcall index_file (void *arg)
-#endif
-{
-int line = 0, found = 0;
-unsigned char key[256];
-ThreadArg *args = arg;
-int ch, len = 0, slot;
-time_t tod[1];
-BtKey ptr;
-BtDb *bt;
-FILE *in;
-
- bt = bt_open (args->mgr);
- time (tod);
-
- switch(args->type | 0x20)
- {
- case 'w':
- fprintf(stderr, "started indexing for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- if( bt_insertkey (bt, key, len, ++line, *tod) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys\n", args->infile, line);
- break;
-
- case 'd':
- fprintf(stderr, "started deleting keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( bt_deletekey (bt, key, len, 0) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for keys, %d \n", args->infile, line);
- break;
-
- case 'f':
- fprintf(stderr, "started finding keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( bt_findkey (bt, key, len) )
- found++;
- else if( bt->err )
- fprintf(stderr, "Error %d Syserr %d Line: %d\n", bt->err, errno, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys, found %d\n", args->infile, line, found);
- break;
-
- case 's':
- len = key[0] = 0;
-
- fprintf(stderr, "started reading\n");
-
- if( slot = bt_startkey (bt, key, len) )
- slot--;
- else
- fprintf(stderr, "Error %d in StartKey. Syserror: %d\n", bt->err, errno), exit(0);
-
- while( slot = bt_nextkey (bt, slot) ) {
- ptr = bt_key(bt, slot);
- fwrite (ptr->key, ptr->len, 1, stdout);
- fputc ('\n', stdout);
- }
- }
-
- bt_close (bt);
-#ifdef unix
- return NULL;
-#else
- return 0;
-#endif
-}
-
-typedef struct timeval timer;
-
-int main (int argc, char **argv)
-{
-int idx, cnt, len, slot, err;
-int segsize, bits = 16;
-#ifdef unix
-pthread_t *threads;
-timer start, stop;
-#else
-time_t start[1], stop[1];
-HANDLE *threads;
-#endif
-double real_time;
-ThreadArg *args;
-uint map = 0;
-char key[1];
-BtMgr *mgr;
-BtKey ptr;
-BtDb *bt;
-
- if( argc < 3 ) {
- fprintf (stderr, "Usage: %s idx_file Read/Write/Scan/Delete/Find [page_bits mapped_segments seg_bits hash_size src_file1 src_file2 ... ]\n", argv[0]);
- fprintf (stderr, " where page_bits is the page size in bits\n");
- fprintf (stderr, " mapped_segments is the number of mmap segments in buffer pool\n");
- fprintf (stderr, " seg_bits is the size of individual segments in buffer pool in pages in bits\n");
- fprintf (stderr, " hash_size is the size of buffer pool hash table\n");
- fprintf (stderr, " src_file1 thru src_filen are files of keys separated by newline\n");
- exit(0);
- }
-
-#ifdef unix
- gettimeofday(&start, NULL);
-#else
- time(start);
-#endif
-
- if( argc > 3 )
- bits = atoi(argv[3]);
-
- if( argc > 4 )
- map = atoi(argv[4]);
-
- if( map > 65536 )
- fprintf (stderr, "Warning: mapped_pool > 65536 segments\n");
-
- if( argc > 5 )
- segsize = atoi(argv[5]);
- else
- segsize = 4; // 16 pages per mmap segment
-
- cnt = argc - 6;
-#ifdef unix
- threads = malloc (cnt * sizeof(pthread_t));
-#else
- threads = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, cnt * sizeof(HANDLE));
-#endif
- args = malloc (cnt * sizeof(ThreadArg));
-
- mgr = bt_mgr ((argv[1]), BT_rw, bits, map, segsize, map / 8);
-
- if( !mgr ) {
- fprintf(stderr, "Index Open Error %s\n", argv[1]);
- exit (1);
- }
-
- // fire off threads
-
- for( idx = 0; idx < cnt; idx++ ) {
- args[idx].infile = argv[idx + 6];
- args[idx].type = argv[2][0];
- args[idx].mgr = mgr;
-#ifdef unix
- if( err = pthread_create (threads + idx, NULL, index_file, args + idx) )
- fprintf(stderr, "Error creating thread %d\n", err);
-#else
- threads[idx] = (HANDLE)_beginthreadex(NULL, 65536, index_file, args + idx, 0, NULL);
-#endif
- }
-
- // wait for termination
-
-#ifdef unix
- for( idx = 0; idx < cnt; idx++ )
- pthread_join (threads[idx], NULL);
- gettimeofday(&stop, NULL);
- real_time = 1000.0 * ( stop.tv_sec - start.tv_sec ) + 0.001 * (stop.tv_usec - start.tv_usec );
-#else
- WaitForMultipleObjects (cnt, threads, TRUE, INFINITE);
-
- for( idx = 0; idx < cnt; idx++ )
- CloseHandle(threads[idx]);
-
- time (stop);
- real_time = 1000 * (*stop - *start);
-#endif
- fprintf(stderr, " Time to complete: %.2f seconds\n", real_time/1000);
-
- cnt = 0;
- len = key[0] = 0;
- bt = bt_open (mgr);
-
- fprintf(stderr, "started reading\n");
-
- if( slot = bt_startkey (bt, key, len) )
- slot--;
- else
- fprintf(stderr, "Error %d in StartKey. Syserror: %d\n", bt->err, errno), exit(0);
-
- while( slot = bt_nextkey (bt, slot) )
- cnt++;
-
- fprintf(stderr, " Total keys read %d\n", cnt);
-
- bt_close (bt);
- bt_mgrclose (mgr);
-}
-
-#endif //STANDALONE
+++ /dev/null
-// foster btree version a
-// 16 DEC 2013
-
-// author: karl malbrain, malbrain@cal.berkeley.edu
-
-/*
-This work, including the source code, documentation
-and related data, is placed into the public domain.
-
-The orginal author is Karl Malbrain.
-
-THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
-OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
-MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
-ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
-RESULTING FROM THE USE, MODIFICATION, OR
-REDISTRIBUTION OF THIS SOFTWARE.
-*/
-
-// Please see the project home page for documentation
-// code.google.com/p/high-concurrency-btree
-
-#define _FILE_OFFSET_BITS 64
-#define _LARGEFILE64_SOURCE
-
-#ifdef linux
-#define _GNU_SOURCE
-#endif
-
-#ifdef unix
-#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <sys/time.h>
-#include <sys/mman.h>
-#include <errno.h>
-#include <pthread.h>
-#else
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <fcntl.h>
-#include <process.h>
-#endif
-
-#include <memory.h>
-#include <string.h>
-
-typedef unsigned long long uid;
-
-#ifndef unix
-typedef unsigned long long off64_t;
-typedef unsigned short ushort;
-typedef unsigned int uint;
-#endif
-
-#define BT_ro 0x6f72 // ro
-#define BT_rw 0x7772 // rw
-
-#define BT_maxbits 24 // maximum page size in bits
-#define BT_minbits 9 // minimum page size in bits
-#define BT_minpage (1 << BT_minbits) // minimum page size
-#define BT_maxpage (1 << BT_maxbits) // maximum page size
-
-/*
-There are five lock types for each node in three independent sets:
-1. (set 1) AccessIntent: Sharable. Going to Read the node. Incompatible with NodeDelete.
-2. (set 1) NodeDelete: Exclusive. About to release the node. Incompatible with AccessIntent.
-3. (set 2) ReadLock: Sharable. Read the node. Incompatible with WriteLock.
-4. (set 2) WriteLock: Exclusive. Modify the node. Incompatible with ReadLock and other WriteLocks.
-5. (set 3) ParentLock: Exclusive. Have parent adopt/delete maximum foster child from the node.
-*/
-
-typedef enum{
- BtLockAccess,
- BtLockDelete,
- BtLockRead,
- BtLockWrite,
- BtLockParent
-}BtLock;
-
-// Define the length of the page and key pointers
-
-#define BtId 6
-
-// Page key slot definition.
-
-// If BT_maxbits is 15 or less, you can save 4 bytes
-// for each key stored by making the first two uints
-// into ushorts. You can also save 4 bytes by removing
-// the tod field from the key.
-
-// Keys are marked dead, but remain on the page until
-// it cleanup is called. The fence key (highest key) for
-// the page is always present, even after cleanup.
-
-typedef struct {
- uint off:BT_maxbits; // page offset for key start
- uint dead:1; // set for deleted key
- uint tod; // time-stamp for key
- unsigned char id[BtId]; // id associated with key
-} BtSlot;
-
-// The key structure occupies space at the upper end of
-// each page. It's a length byte followed by the value
-// bytes.
-
-typedef struct {
- unsigned char len;
- unsigned char key[1];
-} *BtKey;
-
-// The first part of an index page.
-// It is immediately followed
-// by the BtSlot array of keys.
-
-typedef struct Page {
- uint cnt; // count of keys in page
- uint act; // count of active keys
- uint min; // next key offset
- uint foster; // count of foster children
- unsigned char bits:6; // page size in bits
- unsigned char dirty:1; // page needs to be cleaned
- unsigned char kill:1; // page is being deleted
- unsigned char lvl; // level of page
- unsigned char right[BtId]; // page number to right
-} *BtPage;
-
-// mode & definition for latch table implementation
-
-enum {
- Write = 1,
- Share = 2
-} LockMode;
-
-// latch table lock structure
-
-// mode is set for write access
-// share is count of read accessors
-// grant write lock when share == 0
-
-typedef struct {
- int mode:1;
- int share:31;
-} BtLatch;
-
-typedef struct {
- BtLatch readwr[1]; // read/write page lock
- BtLatch access[1]; // Access Intent/Page delete
- BtLatch parent[1]; // adoption of foster children
-} BtLatchSet;
-
-// The memory mapping hash table buffer manager entry
-
-typedef struct {
- unsigned long long int lru; // number of times accessed
- uid basepage; // mapped base page number
- char *map; // mapped memory pointer
- uint pin; // mapped page pin counter
- uint slot; // slot index in this array
- void *hashprev; // previous cache block for the same hash idx
- void *hashnext; // next cache block for the same hash idx
-#ifndef unix
- HANDLE hmap;
-#endif
-// array of page latch sets, one for each page in map segment
- BtLatchSet pagelatch[0];
-} BtHash;
-
-// The object structure for Btree access
-
-typedef struct {
- uint page_size; // page size
- uint page_bits; // page size in bits
- uint seg_bits; // seg size in pages in bits
- uint mode; // read-write mode
-#ifdef unix
- int idx;
-#else
- HANDLE idx;
-#endif
- uint nodecnt; // highest page cache node in use
- uint nodemax; // highest page cache node allocated
- uint hashmask; // number of pages in mmap segment
- uint hashsize; // size of Hash Table
- uint evicted; // last evicted hash slot
- ushort *cache; // hash index for memory pool
- BtLatch *latch; // latches for hash table slots
- char *nodes; // memory pool page hash nodes
-} BtMgr;
-
-typedef struct {
- BtMgr *mgr; // buffer manager for thread
- BtPage temp; // temporary frame buffer (memory mapped/file IO)
- BtPage alloc; // frame buffer for alloc page ( page 0 )
- BtPage cursor; // cached frame for start/next (never mapped)
- BtPage frame; // spare frame for the page split (never mapped)
- BtPage zero; // page frame for zeroes at end of file
- BtPage page; // current page
- uid page_no; // current page number
- uid cursor_page; // current cursor page number
- unsigned char *mem; // frame, cursor, page memory buffer
- int err; // last error
-} BtDb;
-
-typedef enum {
- BTERR_ok = 0,
- BTERR_again,
- BTERR_struct,
- BTERR_ovflw,
- BTERR_lock,
- BTERR_map,
- BTERR_wrt,
- BTERR_hash
-} BTERR;
-
-// B-Tree functions
-extern void bt_close (BtDb *bt);
-extern BtDb *bt_open (BtMgr *mgr);
-extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod);
-extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
-extern uid bt_findkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_nextkey (BtDb *bt, uint slot);
-
-// manager functions
-extern BtMgr *bt_mgr (char *name, uint mode, uint bits, uint cacheblk, uint segsize, uint hashsize);
-void bt_mgrclose (BtMgr *mgr);
-
-// Helper functions to return cursor slot values
-
-extern BtKey bt_key (BtDb *bt, uint slot);
-extern uid bt_uid (BtDb *bt, uint slot);
-extern uint bt_tod (BtDb *bt, uint slot);
-
-// BTree page number constants
-#define ALLOC_page 0
-#define ROOT_page 1
-
-// Number of levels to create in a new BTree
-
-#define MIN_lvl 2
-
-// The page is allocated from low and hi ends.
-// The key offsets and row-id's are allocated
-// from the bottom, while the text of the key
-// is allocated from the top. When the two
-// areas meet, the page is split into two.
-
-// A key consists of a length byte, two bytes of
-// index number (0 - 65534), and up to 253 bytes
-// of key value. Duplicate keys are discarded.
-// Associated with each key is a 48 bit row-id.
-
-// The b-tree root is always located at page 1.
-// The first leaf page of level zero is always
-// located on page 2.
-
-// When to root page fills, it is split in two and
-// the tree height is raised by a new root at page
-// one with two keys.
-
-// Deleted keys are marked with a dead bit until
-// page cleanup The fence key for a node is always
-// present, even after deletion and cleanup.
-
-// Groups of pages called segments from the btree are
-// cached with memory mapping. A hash table is used to keep
-// track of the cached segments. This behaviour is controlled
-// by the cache block size parameter to bt_open.
-
-// To achieve maximum concurrency one page is locked at a time
-// as the tree is traversed to find leaf key in question.
-
-// An adoption traversal leaves the parent node locked as the
-// tree is traversed to the level in quesiton.
-
-// Page 0 is dedicated to lock for new page extensions,
-// and chains empty pages together for reuse.
-
-// Empty pages are chained together through the ALLOC page and reused.
-
-// Access macros to address slot and key values from the page
-
-#define slotptr(page, slot) (((BtSlot *)(page+1)) + (slot-1))
-#define keyptr(page, slot) ((BtKey)((unsigned char*)(page) + slotptr(page, slot)->off))
-
-void bt_putid(unsigned char *dest, uid id)
-{
-int i = BtId;
-
- while( i-- )
- dest[i] = (unsigned char)id, id >>= 8;
-}
-
-uid bt_getid(unsigned char *src)
-{
-uid id = 0;
-int i;
-
- for( i = 0; i < BtId; i++ )
- id <<= 8, id |= *src++;
-
- return id;
-}
-
-void bt_mgrclose (BtMgr *mgr)
-{
-BtHash *hash;
-uint slot;
-
- // release mapped pages
-
- for( slot = 0; slot < mgr->nodemax; slot++ ) {
- hash = (BtHash *)(mgr->nodes + slot * (sizeof(BtHash) + (mgr->hashmask + 1) * sizeof(BtLatchSet)));
- if( hash->slot )
-#ifdef unix
- munmap (hash->map, (mgr->hashmask+1) << mgr->page_bits);
-#else
- {
- FlushViewOfFile(hash->map, 0);
- UnmapViewOfFile(hash->map);
- CloseHandle(hash->hmap);
- }
-#endif
- }
-
-#ifdef unix
- close (mgr->idx);
- free (mgr->nodes);
- free (mgr->cache);
- free (mgr->latch);
-#else
- FlushFileBuffers(mgr->idx);
- CloseHandle(mgr->idx);
- GlobalFree (mgr->nodes);
- GlobalFree (mgr->cache);
- GlobalFree (mgr->latch);
-#endif
-}
-
-// close and release memory
-
-void bt_close (BtDb *bt)
-{
-#ifdef unix
- if ( bt->mem )
- free (bt->mem);
- free (bt);
-#else
- if ( bt->mem)
- VirtualFree (bt->mem, 0, MEM_RELEASE);
- GlobalFree (bt);
-#endif
-}
-
-// open/create new btree buffer manager
-
-// call with file_name, BT_openmode, bits in page size (e.g. 16),
-// size of mapped page cache (e.g. 8192)
-
-BtMgr *bt_mgr (char *name, uint mode, uint bits, uint nodemax, uint segsize, uint hashsize)
-{
-uint lvl, attr, cacheblk, last;
-BtPage alloc;
-int lockmode;
-off64_t size;
-uint amt[1];
-BtMgr* mgr;
-BtKey key;
-
-#ifndef unix
-SYSTEM_INFO sysinfo[1];
-#endif
-
- // determine sanity of page size and buffer pool
-
- if( bits > BT_maxbits )
- bits = BT_maxbits;
- else if( bits < BT_minbits )
- bits = BT_minbits;
-
- if( !nodemax )
- return NULL; // must have buffer pool
-
-#ifdef unix
- mgr = calloc (1, sizeof(BtMgr));
-
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
- lockmode = 1;
- break;
-
- case BT_ro:
- default:
- mgr->idx = open ((char*)name, O_RDONLY);
- lockmode = 0;
- break;
- }
- if( mgr->idx == -1 )
- return free(mgr), NULL;
-
- cacheblk = 4096; // minimum mmap segment size for unix
-
-#else
- mgr = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtMgr));
- attr = FILE_ATTRIBUTE_NORMAL;
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
- lockmode = 1;
- break;
-
- case BT_ro:
- default:
- mgr->idx = CreateFile(name, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, attr, NULL);
- lockmode = 0;
- break;
- }
- if( mgr->idx == INVALID_HANDLE_VALUE )
- return GlobalFree(mgr), NULL;
-
- // normalize cacheblk to multiple of sysinfo->dwAllocationGranularity
- GetSystemInfo(sysinfo);
- cacheblk = sysinfo->dwAllocationGranularity;
-#endif
-
-#ifdef unix
- alloc = malloc (BT_maxpage);
- *amt = 0;
-
- // read minimum page size to get root info
-
- if( size = lseek (mgr->idx, 0L, 2) ) {
- if( pread(mgr->idx, alloc, BT_minpage, 0) == BT_minpage )
- bits = alloc->bits;
- else
- return free(mgr), free(alloc), NULL;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#else
- alloc = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
- size = GetFileSize(mgr->idx, amt);
-
- if( size || *amt ) {
- if( !ReadFile(mgr->idx, (char *)alloc, BT_minpage, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- bits = alloc->bits;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- mgr->page_size = 1 << bits;
- mgr->page_bits = bits;
-
- mgr->nodemax = nodemax;
- mgr->mode = mode;
-
- if( cacheblk < mgr->page_size )
- cacheblk = mgr->page_size;
-
- // mask for partial memmaps
-
- mgr->hashmask = (cacheblk >> bits) - 1;
-
- // see if requested number of pages per memmap is greater
-
- if( (1 << segsize) > mgr->hashmask )
- mgr->hashmask = (1 << segsize) - 1;
-
- mgr->seg_bits = 0;
-
- while( (1 << mgr->seg_bits) <= mgr->hashmask )
- mgr->seg_bits++;
-
- mgr->hashsize = hashsize;
-
-#ifdef unix
- mgr->nodes = calloc (nodemax, (sizeof(BtHash) + (mgr->hashmask + 1) * sizeof(BtLatchSet)));
- mgr->cache = calloc (hashsize, sizeof(ushort));
- mgr->latch = calloc (hashsize, sizeof(BtLatch));
-#else
- mgr->nodes = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, cacheblk * (sizeof(BtHash) + (mgr->hashmask + 1) * sizeof(BtLatchSet)));
- mgr->cache = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(ushort));
- mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtLatch));
-#endif
-
- if( size || *amt )
- goto mgrxit;
-
- // initializes an empty b-tree with root page and page of leaves
-
- memset (alloc, 0, 1 << bits);
- bt_putid(slotptr(alloc, 2)->id, MIN_lvl+1);
- alloc->bits = mgr->page_bits;
-
-#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- memset (alloc, 0, 1 << bits);
- alloc->bits = mgr->page_bits;
-
- for( lvl=MIN_lvl; lvl--; ) {
- slotptr(alloc, 1)->off = mgr->page_size - 3;
- bt_putid(slotptr(alloc, 1)->id, lvl ? MIN_lvl - lvl + 1 : 0); // next(lower) page number
- key = keyptr(alloc, 1);
- key->len = 2; // create stopper key
- key->key[0] = 0xff;
- key->key[1] = 0xff;
- alloc->min = mgr->page_size - 3;
- alloc->lvl = lvl;
- alloc->cnt = 1;
- alloc->act = 1;
-#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
- // create empty page area by writing last page of first
- // cache area (other pages are zeroed by O/S)
-
- if( mgr->hashmask ) {
- memset(alloc, 0, mgr->page_size);
- last = mgr->hashmask;
-
- while( last < MIN_lvl + 1 )
- last += mgr->hashmask + 1;
-
-#ifdef unix
- pwrite(mgr->idx, alloc, mgr->page_size, last << mgr->page_bits);
-#else
- SetFilePointer (mgr->idx, last << mgr->page_bits, NULL, FILE_BEGIN);
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
-mgrxit:
-#ifdef unix
- free (alloc);
-#else
- VirtualFree (alloc, 0, MEM_RELEASE);
-#endif
- return mgr;
-}
-
-// open BTree access method
-// based on buffer manager
-
-BtDb *bt_open (BtMgr *mgr)
-{
-BtDb *bt = malloc (sizeof(*bt));
-
- memset (bt, 0, sizeof(*bt));
- bt->mgr = mgr;
-#ifdef unix
- bt->mem = malloc (3 *mgr->page_size);
-#else
- bt->mem = VirtualAlloc(NULL, 3 * mgr->page_size, MEM_COMMIT, PAGE_READWRITE);
-#endif
- bt->frame = (BtPage)bt->mem;
- bt->zero = (BtPage)(bt->mem + 1 * mgr->page_size);
- bt->cursor = (BtPage)(bt->mem + 2 * mgr->page_size);
- return bt;
-}
-
-// compare two keys, returning > 0, = 0, or < 0
-// as the comparison value
-
-int keycmp (BtKey key1, unsigned char *key2, uint len2)
-{
-uint len1 = key1->len;
-int ans;
-
- if( ans = memcmp (key1->key, key2, len1 > len2 ? len2 : len1) )
- return ans;
-
- if( len1 > len2 )
- return 1;
- if( len1 < len2 )
- return -1;
-
- return 0;
-}
-
-// Latch Manager
-
-// wait until write lock mode is clear
-// and add 1 to the share count
-
-void bt_readlock(BtLatch *latch)
-{
- do {
- // add one to counter, check write bit
-
-#ifdef unix
- if( ~__sync_fetch_and_add((int *)latch, Share) & Write )
- return;
-#else
- if( ~InterlockedAdd((int *)latch, Share) & Write )
- return;
-#endif
- // didn't get latch, reset counter by one
-
-#ifdef unix
- __sync_fetch_and_add((int *)latch, -Share);
-#else
- InterlockedAdd ((int *)latch, -Share);
-#endif
-
- // and yield
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- } while( 1 );
-}
-
-// wait for other read and write latches to relinquish
-
-void bt_writelock(BtLatch *latch)
-{
-int prev, ours = 0;
-
- do {
- // see if we can get write access
- // with no readers
-#ifdef unix
- prev = __sync_fetch_and_or((int *)latch, Write);
-#else
- prev = InterlockedOr((int *)latch, Write);
-#endif
-
- if( ~prev & 1 )
- ours++; // it's ours
-
- if( !(prev >> 1) && ours )
- return;
-
- // otherwise yield
-
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- } while( 1 );
-}
-
-// try to obtain write lock
-
-// return 1 if obtained,
-// 0 if already write locked
-
-int bt_writetry(BtLatch *latch)
-{
-int prev, ours = 0;
-
- do {
- // see if we can get write access
- // with no readers
-#ifdef unix
- prev = __sync_fetch_and_or((int *)latch, Write);
-#else
- prev = InterlockedOr((int *)latch, Write);
-#endif
-
- if( ~prev & 1 )
- ours++; // it's ours
-
- if( !ours )
- return 0;
-
- if( !(prev >> 1) && ours )
- return 1;
-
- // otherwise yield
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- } while( 1 );
-}
-
-// clear write mode
-
-void bt_releasewrite(BtLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_and((int *)latch, ~Write);
-#else
- InterlockedAnd ((int *)latch, ~Write);
-#endif
-}
-
-// decrement reader count
-
-void bt_releaseread(BtLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_add((int *)latch, -Share);
-#else
- InterlockedAdd((int *)latch, -Share);
-#endif
-}
-
-// Buffer Pool mgr
-
-// find segment in cache
-// return NULL if not there
-// otherwise return node
-
-BtHash *bt_findhash(BtDb *bt, uid page_no, uint idx)
-{
-BtHash *hash;
-uint slot;
-
- // compute cache block first page and hash idx
-
- if( slot = bt->mgr->cache[idx] )
- hash = (BtHash *)(bt->mgr->nodes + slot * (sizeof(BtHash) + (bt->mgr->hashmask + 1) * sizeof(BtLatchSet)));
- else
- return NULL;
-
- page_no &= ~bt->mgr->hashmask;
-
- while( hash->basepage != page_no )
- if( hash = hash->hashnext )
- continue;
- else
- return NULL;
-
- return hash;
-}
-
-// add segment to hash table
-
-void bt_linkhash(BtDb *bt, BtHash *hash, uid page_no, int idx)
-{
-BtHash *node;
-uint slot;
-
- hash->hashprev = hash->hashnext = NULL;
- hash->basepage = page_no & ~bt->mgr->hashmask;
- hash->pin = 1;
- hash->lru = 1;
-
- if( slot = bt->mgr->cache[idx] ) {
- node = (BtHash *)(bt->mgr->nodes + slot * (sizeof(BtHash) + (bt->mgr->hashmask + 1) * sizeof(BtLatchSet)));
- hash->hashnext = node;
- node->hashprev = hash;
- }
-
- bt->mgr->cache[idx] = hash->slot;
-}
-
-// find best segment to evict from buffer pool
-
-BtHash *bt_findlru (BtDb *bt, uint slot)
-{
-unsigned long long int target = ~0LL;
-BtHash *hash = NULL, *node;
-
- if( !slot )
- return NULL;
-
- node = (BtHash *)(bt->mgr->nodes + slot * (sizeof(BtHash) + (bt->mgr->hashmask + 1) * sizeof(BtLatchSet)));
-
- do {
- if( node->pin )
- continue;
- if( node->lru > target )
- continue;
- target = node->lru;
- hash = node;
- } while( node = node->hashnext );
-
- return hash;
-}
-
-// map new segment to virtual memory
-
-BTERR bt_mapsegment(BtDb *bt, BtHash *hash, uid page_no)
-{
-off64_t off = (page_no & ~bt->mgr->hashmask) << bt->mgr->page_bits;
-off64_t limit = off + ((bt->mgr->hashmask+1) << bt->mgr->page_bits);
-int flag;
-
-#ifdef unix
- flag = PROT_READ | ( bt->mgr->mode == BT_ro ? 0 : PROT_WRITE );
- hash->map = mmap (0, (bt->mgr->hashmask+1) << bt->mgr->page_bits, flag, MAP_SHARED, bt->mgr->idx, off);
- if( hash->map == MAP_FAILED )
- return bt->err = BTERR_map;
-#else
- flag = ( bt->mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
- hash->hmap = CreateFileMapping(bt->mgr->idx, NULL, flag, (DWORD)(limit >> 32), (DWORD)limit, NULL);
- if( !hash->hmap )
- return bt->err = BTERR_map;
-
- flag = ( bt->mgr->mode == BT_ro ? FILE_MAP_READ : FILE_MAP_WRITE );
- hash->map = MapViewOfFile(hash->hmap, flag, (DWORD)(off >> 32), (DWORD)off, (bt->mgr->hashmask+1) << bt->mgr->page_bits);
- if( !hash->map )
- return bt->err = BTERR_map;
-#endif
- return bt->err = 0;
-}
-
-// find or place requested page in segment-cache
-// return hash table entry
-
-BtHash *bt_hashpage(BtDb *bt, uid page_no)
-{
-BtHash *hash, *node, *next;
-uint slot, idx, victim;
-BtLatchSet *set;
-
- // lock hash table chain
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx]);
-
- // look up in hash table
-
- if( hash = bt_findhash(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&hash->pin, 1);
-#else
- InterlockedIncrement (&hash->pin);
-#endif
- bt_releaseread (&bt->mgr->latch[idx]);
- hash->lru++;
- return hash;
- }
-
- // upgrade to write lock
-
- bt_releaseread (&bt->mgr->latch[idx]);
- bt_writelock (&bt->mgr->latch[idx]);
-
- // try to find page in cache with write lock
-
- if( hash = bt_findhash(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&hash->pin, 1);
-#else
- InterlockedIncrement (&hash->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx]);
- hash->lru++;
- return hash;
- }
-
- // allocate a new hash node
- // and add to hash table
-
-#ifdef unix
- slot = __sync_fetch_and_add(&bt->mgr->nodecnt, 1);
-#else
- slot = InterlockedIncrement (&bt->mgr->nodecnt) - 1;
-#endif
-
- if( ++slot < bt->mgr->nodemax ) {
- hash = (BtHash *)(bt->mgr->nodes + slot * (sizeof(BtHash) + (bt->mgr->hashmask + 1) * sizeof(BtLatchSet)));
- hash->slot = slot;
-
- if( bt_mapsegment(bt, hash, page_no) )
- return NULL;
-
- bt_linkhash(bt, hash, page_no, idx);
- bt_releasewrite (&bt->mgr->latch[idx]);
- return hash;
- }
-
- // hash table is full
- // find best cache entry to evict
-
-#ifdef unix
- __sync_fetch_and_add(&bt->mgr->nodecnt, -1);
-#else
- InterlockedDecrement (&bt->mgr->nodecnt);
-#endif
-
- while( 1 ) {
-#ifdef unix
- victim = __sync_fetch_and_add(&bt->mgr->evicted, 1);
-#else
- victim = InterlockedIncrement (&bt->mgr->evicted) - 1;
-#endif
- victim %= bt->mgr->hashsize;
-
- // try to get write lock
- // skip entry if not obtained
-
- if( !bt_writetry (&bt->mgr->latch[victim]) )
- continue;
-
- // if cache entry is empty
- // or no slots are unpinned
- // skip this entry
-
- if( !(hash = bt_findlru(bt, bt->mgr->cache[victim])) ) {
- bt_releasewrite (&bt->mgr->latch[victim]);
- continue;
- }
-
- // unlink victim hash node from hash table
-
- if( node = hash->hashprev )
- node->hashnext = hash->hashnext;
- else if( node = hash->hashnext )
- bt->mgr->cache[victim] = node->slot;
- else
- bt->mgr->cache[victim] = 0;
-
- if( node = hash->hashnext )
- node->hashprev = hash->hashprev;
-
- // remove old file mapping
-#ifdef unix
- munmap (hash->map, (bt->mgr->hashmask+1) << bt->mgr->page_bits);
-#else
- FlushViewOfFile(hash->map, 0);
- UnmapViewOfFile(hash->map);
- CloseHandle(hash->hmap);
-#endif
- hash->map = NULL;
- bt_releasewrite (&bt->mgr->latch[victim]);
-
- // create new file mapping
- // and link into hash table
-
- if( bt_mapsegment(bt, hash, page_no) )
- return NULL;
-
- bt_linkhash(bt, hash, page_no, idx);
- bt_releasewrite (&bt->mgr->latch[idx]);
- return hash;
- }
-}
-
-// place write, read, or parent lock on requested page_no.
-// pin to buffer pool
-
-BTERR bt_lockpage(BtDb *bt, uid page_no, BtLock mode, BtPage *page)
-{
-BtLatchSet *set;
-BtHash *hash;
-uint subpage;
-
- // find/create maping in hash table
-
- if( hash = bt_hashpage(bt, page_no) )
- subpage = (uint)(page_no & bt->mgr->hashmask); // page within mapping
- else
- return bt->err;
-
- set = hash->pagelatch + subpage;
-
- switch( mode ) {
- case BtLockRead:
- bt_readlock (set->readwr);
- break;
- case BtLockWrite:
- bt_writelock (set->readwr);
- break;
- case BtLockAccess:
- bt_readlock (set->access);
- break;
- case BtLockDelete:
- bt_writelock (set->access);
- break;
- case BtLockParent:
- bt_writelock (set->parent);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
- if( page )
- *page = (BtPage)(hash->map + (subpage << bt->mgr->page_bits));
-
- return bt->err = 0;
-}
-
-// remove write, read, or parent lock on requested page_no.
-
-BTERR bt_unlockpage(BtDb *bt, uid page_no, BtLock mode)
-{
-uint subpage, idx;
-BtLatchSet *set;
-BtHash *hash;
-
- // since page is pinned
- // it should still be in the buffer pool
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx]);
-
- if( hash = bt_findhash(bt, page_no, idx) )
- subpage = (uint)(page_no & bt->mgr->hashmask);
- else
- return bt->err = BTERR_hash;
-
- bt_releaseread (&bt->mgr->latch[idx]);
- set = hash->pagelatch + subpage;
-
- switch( mode ) {
- case BtLockRead:
- bt_releaseread (set->readwr);
- break;
- case BtLockWrite:
- bt_releasewrite (set->readwr);
- break;
- case BtLockAccess:
- bt_releaseread (set->access);
- break;
- case BtLockDelete:
- bt_releasewrite (set->access);
- break;
- case BtLockParent:
- bt_releasewrite (set->parent);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
-#ifdef unix
- __sync_fetch_and_add(&hash->pin, -1);
-#else
- InterlockedDecrement (&hash->pin);
-#endif
- return bt->err = 0;
-}
-
-// deallocate a deleted page that has no tree pointers
-// place on free chain out of allocator page
-
-BTERR bt_freepage(BtDb *bt, uid page_no)
-{
- // obtain delete lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- // obtain write lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // lock allocation page
-
- if ( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return bt->err;
-
- // store chain in first key
- bt_putid(slotptr(bt->temp, 1)->id, bt_getid(slotptr(bt->alloc, 1)->id));
- bt_putid(slotptr(bt->alloc, 1)->id, page_no);
-
- // unlock page zero
-
- if( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return bt->err;
-
- // remove write lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // remove delete lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockDelete) )
- return bt->err;
-
- return 0;
-}
-
-// allocate a new page and write page into it
-
-uid bt_newpage(BtDb *bt, BtPage page)
-{
-uid new_page;
-BtPage pmap;
-int reuse;
-
- // lock page zero
-
- if ( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return 0;
-
- // use empty chain first
- // else allocate empty page
-
- if( new_page = bt_getid(slotptr(bt->alloc, 1)->id) ) {
- if( bt_lockpage (bt, new_page, BtLockWrite, &bt->temp) )
- return 0;
- bt_putid(slotptr(bt->alloc, 1)->id, bt_getid(slotptr(bt->temp, 1)->id));
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
- reuse = 1;
- } else {
- new_page = bt_getid(slotptr(bt->alloc, 2)->id);
- bt_putid(slotptr(bt->alloc, 2)->id, new_page+1);
- reuse = 0;
- }
-#ifdef unix
- if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
-
- // if writing first page of hash block, zero last page in the block
-
- if ( !reuse && bt->mgr->hashmask > 0 && (new_page & bt->mgr->hashmask) == 0 )
- {
- // use zero buffer to write zeros
- memset(bt->zero, 0, bt->mgr->page_size);
- if ( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->hashmask) << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
- }
-#else
- // bring new page into page-cache and copy page.
- // this will extend the file into the new pages.
-
- if( bt_lockpage(bt, new_page, BtLockWrite, &pmap) )
- return 0;
-
- memcpy(pmap, page, bt->mgr->page_size);
-
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
-#endif
- // unlock page zero
-
- if ( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return 0;
-
- return new_page;
-}
-
-// find slot in page for given key at a given level
-
-int bt_findslot (BtDb *bt, unsigned char *key, uint len)
-{
-uint diff, higher = bt->page->cnt, low = 1, slot;
-
- // low is the lowest candidate, higher is already
- // tested as .ge. the given key, loop ends when they meet
-
- while( diff = higher - low ) {
- slot = low + ( diff >> 1 );
- if( keycmp (keyptr(bt->page, slot), key, len) < 0 )
- low = slot + 1;
- else
- higher = slot;
- }
-
- return higher;
-}
-
-// find and load page at given level for given key
-// leave page rd or wr locked as requested
-
-int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, uint lock)
-{
-uid page_no = ROOT_page, prevpage = 0;
-uint drill = 0xff, slot;
-uint mode, prevmode;
-
- // start at root of btree and drill down
-
- do {
- // determine lock mode of drill level
- mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead;
-
- bt->page_no = page_no;
-
- // obtain access lock using lock chaining with Access mode
-
- if( page_no > ROOT_page )
- if( bt_lockpage(bt, page_no, BtLockAccess, NULL) )
- return 0;
-
- if( prevpage )
- if( bt_unlockpage(bt, prevpage, prevmode) )
- return 0;
-
- // obtain read lock using lock chaining
- // and pin page contents
-
- if( bt_lockpage(bt, page_no, mode, &bt->page) )
- return 0;
-
- if( page_no > ROOT_page )
- if( bt_unlockpage(bt, page_no, BtLockAccess) )
- return 0;
-
- // re-read and re-lock root after determining actual level of root
-
- if( bt->page_no == ROOT_page )
- if( bt->page->lvl != drill) {
- drill = bt->page->lvl;
-
- if( lock == BtLockWrite && drill == lvl )
- if( bt_unlockpage(bt, page_no, mode) )
- return 0;
- else
- continue;
- }
-
- // if page is being deleted,
- // move back to preceeding page
-
- if( bt->page->kill ) {
- page_no = bt_getid (bt->page->right);
- continue;
- }
-
- // find key on page at this level
- // and descend to requested level
-
- slot = bt_findslot (bt, key, len);
-
- // is this slot a foster child?
-
- if( slot <= bt->page->cnt - bt->page->foster )
- if( drill == lvl )
- return slot;
- else
- drill--;
-
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
- continue;
- else
- return bt->err = BTERR_struct, 0;
-
- // continue down / right using overlapping locks
- // to protect pages being killed or split.
-
- prevmode = mode;
- prevpage = bt->page_no;
- page_no = bt_getid(slotptr(bt->page, slot)->id);
- } while( page_no );
-
- // return error on end of chain
-
- bt->err = BTERR_struct;
- return 0; // return error
-}
-
-// find and delete key on page by marking delete flag bit
-// when page becomes empty, delete it from the btree
-
-BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl)
-{
-unsigned char leftkey[256], rightkey[256];
-uid page_no, right;
-uint slot, tod;
-BtKey ptr;
-
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // if key is found delete it, otherwise ignore request
-
- if( !keycmp (ptr, key, len) )
- if( slotptr(bt->page, slot)->dead == 0 ) {
- slotptr(bt->page,slot)->dead = 1;
- if( slot < bt->page->cnt )
- bt->page->dirty = 1;
- bt->page->act--;
- }
-
- // return if page is not empty, or it has no right sibling
-
- right = bt_getid(bt->page->right);
- page_no = bt->page_no;
-
- if( !right || bt->page->act )
- return bt_unlockpage(bt, page_no, BtLockWrite);
-
- // obtain Parent lock over write lock
-
- if( bt_lockpage(bt, page_no, BtLockParent, NULL) )
- return bt->err;
-
- // cache copy of key to delete
-
- ptr = keyptr(bt->page, bt->page->cnt);
- memcpy(leftkey, ptr, ptr->len + 1);
-
- // lock and map right page
-
- if ( bt_lockpage(bt, right, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // pull contents of next page into current empty page
- memcpy (bt->page, bt->temp, bt->mgr->page_size);
-
- // cache copy of key to update
- ptr = keyptr(bt->temp, bt->temp->cnt);
- memcpy(rightkey, ptr, ptr->len + 1);
-
- // Mark right page as deleted and point it to left page
- // until we can post updates at higher level.
-
- bt_putid(bt->temp->right, page_no);
- bt->temp->kill = 1;
- bt->temp->cnt = 0;
-
- if( bt_unlockpage(bt, right, BtLockWrite) )
- return bt->err;
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // delete old lower key to consolidated node
-
- if( bt_deletekey (bt, leftkey + 1, *leftkey, lvl + 1) )
- return bt->err;
-
- // redirect higher key directly to consolidated node
-
- if( slot = bt_loadpage (bt, rightkey+1, *rightkey, lvl+1, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // since key already exists, update id
-
- if( keycmp (ptr, rightkey+1, *rightkey) )
- return bt->err = BTERR_struct;
-
- slotptr(bt->page, slot)->dead = 0;
- bt_putid(slotptr(bt->page,slot)->id, page_no);
- bt_unlockpage(bt, bt->page_no, BtLockWrite);
-
- // obtain write lock and
- // add right block to free chain
-
- if( bt_freepage (bt, right) )
- return bt->err;
-
- // remove ParentModify lock
-
- if( bt_unlockpage(bt, page_no, BtLockParent) )
- return bt->err;
-
- return 0;
-}
-
-// find key in leaf level and return row-id
-
-uid bt_findkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-BtKey ptr;
-uid id;
-
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- ptr = keyptr(bt->page, slot);
- else
- return 0;
-
- // if key exists, return row-id
- // otherwise return 0
-
- if( ptr->len == len && !memcmp (ptr->key, key, len) )
- id = bt_getid(slotptr(bt->page,slot)->id);
- else
- id = 0;
-
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
-
- return id;
-}
-
-// check page for space available,
-// clean if necessary and return
-// 0 - page needs splitting
-// 1 - go ahead
-
-uint bt_cleanpage(BtDb *bt, uint amt)
-{
-uint nxt = bt->mgr->page_size;
-BtPage page = bt->page;
-uint cnt = 0, idx = 0;
-uint max = page->cnt;
-BtKey key;
-
- if( page->min >= (max+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- // skip cleanup if nothing to reclaim
-
- if( !page->dirty )
- return 0;
-
- memcpy (bt->frame, page, bt->mgr->page_size);
-
- // skip page info and set rest of page to zero
-
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- page->dirty = 0;
- page->act = 0;
-
- // try cleaning up page first
-
- while( cnt++ < max ) {
- // always leave fence key in list
- if( cnt < max && slotptr(bt->frame,cnt)->dead )
- continue;
-
- // copy key
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
-
- // copy slot
- memcpy(slotptr(page, ++idx)->id, slotptr(bt->frame, cnt)->id, BtId);
- if( !(slotptr(page, idx)->dead = slotptr(bt->frame, cnt)->dead) )
- page->act++;
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- }
- page->min = nxt;
- page->cnt = idx;
-
- if( page->min >= (idx+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- return 0;
-}
-
-// add key to page
-// return with page unlocked
-
-BTERR bt_addkeytopage (BtDb *bt, uint slot, unsigned char *key, uint len, uid id, uint tod)
-{
-BtPage page = bt->page;
-uint idx;
-
- // calculate next available slot and copy key into page
-
- page->min -= len + 1;
- ((unsigned char *)page)[page->min] = len;
- memcpy ((unsigned char *)page + page->min +1, key, len );
-
- for( idx = slot; idx < page->cnt; idx++ )
- if( slotptr(page, idx)->dead )
- break;
-
- // now insert key into array before slot
- // preserving the fence slot
-
- if( idx == page->cnt )
- idx++, page->cnt++;
-
- page->act++;
-
- while( idx > slot )
- *slotptr(page, idx) = *slotptr(page, idx -1), idx--;
-
- bt_putid(slotptr(page,slot)->id, id);
- slotptr(page, slot)->off = page->min;
- slotptr(page, slot)->tod = tod;
- slotptr(page, slot)->dead = 0;
-
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
-}
-
-// split the root and raise the height of the btree
-
-BTERR bt_splitroot(BtDb *bt, uid right)
-{
-uint nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-BtPage root = bt->page;
-uid new_page;
-BtKey key;
-
- // Obtain an empty page to use, and copy the left page
- // contents into it. Strip foster child key.
- // Save left fence key.
-
- bt->page->act--;
- bt->page->cnt--;
- bt->page->foster--;
- key = keyptr(bt->page, bt->page->cnt);
- memcpy (fencekey, key, key->len + 1);
-
- if( !(new_page = bt_newpage(bt, bt->page)) )
- return bt->err;
-
- // preserve the page info at the bottom
- // and set rest to zero
-
- memset (root+1, 0, bt->mgr->page_size - sizeof(*root));
-
- // insert left fence key on newroot page
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 1)->id, new_page);
- slotptr(root, 1)->off = nxt;
-
- // insert stopper key on newroot page
- // and increase the root height
-
- nxt -= 3;
- fencekey[0] = 2;
- fencekey[1] = 0xff;
- fencekey[2] = 0xff;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 2)->id, right);
- slotptr(root, 2)->off = nxt;
-
- bt_putid(root->right, 0);
- root->min = nxt; // reset lowest used offset and key count
- root->cnt = 2;
- root->act = 2;
- root->lvl++;
-
- // release root (bt->page)
-
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
-}
-
-// split already locked full node
-// return unlocked.
-
-BTERR bt_splitpage (BtDb *bt)
-{
-uint slot, cnt, idx, max, nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-uid page_no = bt->page_no;
-BtPage page = bt->page;
-uint tod = time(NULL);
-uint lvl = page->lvl;
-uid new_page, right;
-BtKey key;
-
- // initialize frame buffer
-
- memset (bt->frame, 0, bt->mgr->page_size);
- max = page->cnt - page->foster;
- tod = (uint)time(NULL);
- cnt = max / 2;
- idx = 0;
-
- // split higher half of keys to bt->frame
- // leaving foster children in the left node.
-
- while( cnt++ < max ) {
- key = keyptr(page, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)bt->frame + nxt, key, key->len + 1);
- memcpy(slotptr(bt->frame,++idx)->id, slotptr(page,cnt)->id, BtId);
- slotptr(bt->frame, idx)->tod = slotptr(page, cnt)->tod;
- slotptr(bt->frame, idx)->off = nxt;
- bt->frame->act++;
- }
-
- // transfer right link node
-
- if( page_no > ROOT_page ) {
- right = bt_getid (page->right);
- bt_putid(bt->frame->right, right);
- }
-
- bt->frame->bits = bt->mgr->page_bits;
- bt->frame->min = nxt;
- bt->frame->cnt = idx;
- bt->frame->lvl = lvl;
-
- // get new free page and write frame to it.
-
- if( !(new_page = bt_newpage(bt, bt->frame)) )
- return bt->err;
-
- // update lower keys and foster children to continue in old page
-
- memcpy (bt->frame, page, bt->mgr->page_size);
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- nxt = bt->mgr->page_size;
- page->act = 0;
- cnt = 0;
- idx = 0;
-
- // assemble page of smaller keys
- // to remain in the old page
-
- while( cnt++ < max / 2 ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- // assemble old foster child keys
- // add new foster child fence
-
- cnt = bt->frame->cnt - bt->frame->foster - 1;
-
- while( cnt++ < bt->frame->cnt ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- // link new right page
-
- bt_putid (page->right, new_page);
-
- // put new page as smallest foster child key
-
- page->min = nxt;
- page->cnt = idx;
- cnt = page->cnt - page->foster++;
- bt_putid (slotptr(page,cnt)->id, new_page);
-
- // if current page is the root page, split it
-
- if( page_no == ROOT_page )
- return bt_splitroot (bt, new_page);
-
- // release wr lock on page
-
- if( bt_unlockpage (bt, page_no, BtLockWrite) )
- return bt->err;
-
- // obtain ParentModification lock for current page
- // to fix highest foster child on page
-
- if( bt_lockpage (bt, page_no, BtLockParent, NULL) )
- return bt->err;
-
- if( bt_lockpage (bt, page_no, BtLockRead, &page) )
- return bt->err;
-
- // get our old fence key
-
- key = keyptr(page, page->cnt);
- memcpy (fencekey, key, key->len+1);
-
- if( bt_unlockpage (bt, page_no, BtLockRead) )
- return bt->err;
-
- do {
- slot = bt_loadpage (bt, fencekey + 1, *fencekey, lvl + 1, BtLockWrite);
-
- if( !slot )
- return bt->err;
-
- // check if parent page has enough space for largest possible key
-
- if( bt_cleanpage (bt, 256) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- } while( 1 );
-
- // wait until readers from parent get their locks
-
- if( bt_lockpage (bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- if( bt_lockpage (bt, page_no, BtLockWrite, &page) )
- return bt->err;
-
- // switch parent fence key to foster child
-
- if( slotptr(page, page->cnt)->dead )
- slotptr(bt->page, slot)->dead = 1;
- else
- bt_putid (slotptr(bt->page, slot)->id, bt_getid(slotptr(page, page->cnt)->id));
-
- // remove foster child from our page
- // add our new fence key to parent
-
- page->cnt--;
- page->act--;
- page->foster--;
- page->dirty = 1;
- key = keyptr(page, page->cnt);
-
- if( bt_addkeytopage (bt, slot, key->key, key->len, page_no, tod) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockDelete) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockParent) )
- return bt->err;
-
- return bt_unlockpage (bt, page_no, BtLockWrite);
-}
-
-// Insert new key into the btree at leaf level.
-
-BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod)
-{
-uint slot, idx;
-BtPage page;
-BtKey ptr;
-
- while( 1 ) {
- if( slot = bt_loadpage (bt, key, len, 0, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- {
- if ( !bt->err )
- bt->err = BTERR_ovflw;
- return bt->err;
- }
-
- // if key already exists, update id and return
-
- page = bt->page;
-
- if( !keycmp (ptr, key, len) ) {
- slotptr(page, slot)->dead = 0;
- slotptr(page, slot)->tod = tod;
- bt_putid(slotptr(page,slot)->id, id);
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
- }
-
- // check if page has enough space
-
- if( bt_cleanpage (bt, len) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- }
-
- return bt_addkeytopage (bt, slot, key, len, id, tod);
-}
-
-// cache page of keys into cursor and return starting slot for given key
-
-uint bt_startkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-
- // cache page for retrieval
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- memcpy (bt->cursor, bt->page, bt->mgr->page_size);
- bt->cursor_page = bt->page_no;
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
-
- return slot;
-}
-
-// return next slot for cursor page
-// or slide cursor right into next page
-
-uint bt_nextkey (BtDb *bt, uint slot)
-{
-BtPage page;
-uid right;
-
- do {
- right = bt_getid(bt->cursor->right);
- while( slot++ < bt->cursor->cnt - bt->cursor->foster )
- if( slotptr(bt->cursor,slot)->dead )
- continue;
- else if( right || (slot < bt->cursor->cnt - bt->cursor->foster) )
- return slot;
- else
- break;
-
- if( !right )
- break;
-
- bt->cursor_page = right;
-
- if( bt_lockpage(bt, right, BtLockRead, &page) )
- return 0;
-
- memcpy (bt->cursor, page, bt->mgr->page_size);
-
- if ( bt_unlockpage(bt, right, BtLockRead) )
- return 0;
-
- slot = 0;
- } while( 1 );
-
- return bt->err = 0;
-}
-
-BtKey bt_key(BtDb *bt, uint slot)
-{
- return keyptr(bt->cursor, slot);
-}
-
-uid bt_uid(BtDb *bt, uint slot)
-{
- return bt_getid(slotptr(bt->cursor,slot)->id);
-}
-
-uint bt_tod(BtDb *bt, uint slot)
-{
- return slotptr(bt->cursor,slot)->tod;
-}
-
-
-#ifdef STANDALONE
-
-typedef struct {
- char type, num;
- char *infile;
- BtMgr *mgr;
-} ThreadArg;
-
-// standalone program to index file of keys
-// then list them onto std-out
-
-#ifdef unix
-void *index_file (void *arg)
-#else
-uint __stdcall index_file (void *arg)
-#endif
-{
-int line = 0, found = 0;
-unsigned char key[256];
-ThreadArg *args = arg;
-int ch, len = 0, slot;
-time_t tod[1];
-BtKey ptr;
-BtDb *bt;
-FILE *in;
-
- bt = bt_open (args->mgr);
- time (tod);
-
- switch(args->type | 0x20)
- {
- case 'w':
- fprintf(stderr, "started indexing for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
-
- if( args->num )
- sprintf((char *)key+len, "%.9d", line), len += 9;
-
- if( bt_insertkey (bt, key, len, line, *tod) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys\n", args->infile, line);
- break;
-
- case 'd':
- fprintf(stderr, "started deleting keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( bt_deletekey (bt, key, len, 0) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for keys, %d \n", args->infile, line);
- break;
-
- case 'f':
- fprintf(stderr, "started finding keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( bt_findkey (bt, key, len) )
- found++;
- else if( bt->err )
- fprintf(stderr, "Error %d Syserr %d Line: %d\n", bt->err, errno, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys, found %d\n", args->infile, line, found);
- break;
-
- case 's':
- len = key[0] = 0;
-
- fprintf(stderr, "started reading\n");
-
- if( slot = bt_startkey (bt, key, len) )
- slot--;
- else
- fprintf(stderr, "Error %d in StartKey. Syserror: %d\n", bt->err, errno), exit(0);
-
- while( slot = bt_nextkey (bt, slot) ) {
- ptr = bt_key(bt, slot);
- fwrite (ptr->key, ptr->len, 1, stdout);
- fputc ('\n', stdout);
- }
- }
-
- bt_close (bt);
-#ifdef unix
- return NULL;
-#else
- return 0;
-#endif
-}
-
-typedef struct timeval timer;
-
-int main (int argc, char **argv)
-{
-int idx, cnt, len, slot, err;
-int segsize, bits = 16;
-#ifdef unix
-pthread_t *threads;
-timer start, stop;
-#else
-time_t start[1], stop[1];
-HANDLE *threads;
-#endif
-double real_time;
-ThreadArg *args;
-uint map = 0;
-int num = 0;
-char key[1];
-BtMgr *mgr;
-BtKey ptr;
-BtDb *bt;
-
- if( argc < 3 ) {
- fprintf (stderr, "Usage: %s idx_file Read/Write/Scan/Delete/Find [page_bits mapped_segments seg_bits line_numbers src_file1 src_file2 ... ]\n", argv[0]);
- fprintf (stderr, " where page_bits is the page size in bits\n");
- fprintf (stderr, " mapped_segments is the number of mmap segments in buffer pool\n");
- fprintf (stderr, " seg_bits is the size of individual segments in buffer pool in pages in bits\n");
- fprintf (stderr, " line_numbers = 1 to append line numbers to keys\n");
- fprintf (stderr, " src_file1 thru src_filen are files of keys separated by newline\n");
- exit(0);
- }
-
-#ifdef unix
- gettimeofday(&start, NULL);
-#else
- time(start);
-#endif
-
- if( argc > 3 )
- bits = atoi(argv[3]);
-
- if( argc > 4 )
- map = atoi(argv[4]);
-
- if( map > 65536 )
- fprintf (stderr, "Warning: mapped_pool > 65536 segments\n");
-
- if( argc > 5 )
- segsize = atoi(argv[5]);
- else
- segsize = 4; // 16 pages per mmap segment
-
- if( argc > 6 )
- num = atoi(argv[6]);
-
- cnt = argc - 7;
-#ifdef unix
- threads = malloc (cnt * sizeof(pthread_t));
-#else
- threads = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, cnt * sizeof(HANDLE));
-#endif
- args = malloc (cnt * sizeof(ThreadArg));
-
- mgr = bt_mgr ((argv[1]), BT_rw, bits, map, segsize, map / 8);
-
- if( !mgr ) {
- fprintf(stderr, "Index Open Error %s\n", argv[1]);
- exit (1);
- }
-
- // fire off threads
-
- for( idx = 0; idx < cnt; idx++ ) {
- args[idx].infile = argv[idx + 7];
- args[idx].type = argv[2][0];
- args[idx].mgr = mgr;
- args[idx].num = num;
-#ifdef unix
- if( err = pthread_create (threads + idx, NULL, index_file, args + idx) )
- fprintf(stderr, "Error creating thread %d\n", err);
-#else
- threads[idx] = (HANDLE)_beginthreadex(NULL, 65536, index_file, args + idx, 0, NULL);
-#endif
- }
-
- // wait for termination
-
-#ifdef unix
- for( idx = 0; idx < cnt; idx++ )
- pthread_join (threads[idx], NULL);
- gettimeofday(&stop, NULL);
- real_time = 1000.0 * ( stop.tv_sec - start.tv_sec ) + 0.001 * (stop.tv_usec - start.tv_usec );
-#else
- WaitForMultipleObjects (cnt, threads, TRUE, INFINITE);
-
- for( idx = 0; idx < cnt; idx++ )
- CloseHandle(threads[idx]);
-
- time (stop);
- real_time = 1000 * (*stop - *start);
-#endif
- fprintf(stderr, " Time to complete: %.2f seconds\n", real_time/1000);
-
- cnt = 0;
- len = key[0] = 0;
- bt = bt_open (mgr);
-
- fprintf(stderr, "started reading\n");
-
- if( slot = bt_startkey (bt, key, len) )
- slot--;
- else
- fprintf(stderr, "Error %d in StartKey. Syserror: %d\n", bt->err, errno), exit(0);
-
- while( slot = bt_nextkey (bt, slot) )
- cnt++;
-
- fprintf(stderr, " Total keys read %d\n", cnt);
-
- bt_close (bt);
- bt_mgrclose (mgr);
-}
-
-#endif //STANDALONE
+++ /dev/null
-// foster btree version b
-// 22 DEC 2013
-
-// author: karl malbrain, malbrain@cal.berkeley.edu
-
-/*
-This work, including the source code, documentation
-and related data, is placed into the public domain.
-
-The orginal author is Karl Malbrain.
-
-THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
-OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
-MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
-ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
-RESULTING FROM THE USE, MODIFICATION, OR
-REDISTRIBUTION OF THIS SOFTWARE.
-*/
-
-// Please see the project home page for documentation
-// code.google.com/p/high-concurrency-btree
-
-#define _FILE_OFFSET_BITS 64
-#define _LARGEFILE64_SOURCE
-
-#ifdef linux
-#define _GNU_SOURCE
-#endif
-
-#ifdef unix
-#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <sys/time.h>
-#include <sys/mman.h>
-#include <errno.h>
-#include <pthread.h>
-#else
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <fcntl.h>
-#include <process.h>
-#include <intrin.h>
-#endif
-
-#include <memory.h>
-#include <string.h>
-
-typedef unsigned long long uid;
-
-#ifndef unix
-typedef unsigned long long off64_t;
-typedef unsigned short ushort;
-typedef unsigned int uint;
-#endif
-
-#define BT_ro 0x6f72 // ro
-#define BT_rw 0x7772 // rw
-
-#define BT_maxbits 24 // maximum page size in bits
-#define BT_minbits 9 // minimum page size in bits
-#define BT_minpage (1 << BT_minbits) // minimum page size
-#define BT_maxpage (1 << BT_maxbits) // maximum page size
-
-/*
-There are five lock types for each node in three independent sets:
-1. (set 1) AccessIntent: Sharable. Going to Read the node. Incompatible with NodeDelete.
-2. (set 1) NodeDelete: Exclusive. About to release the node. Incompatible with AccessIntent.
-3. (set 2) ReadLock: Sharable. Read the node. Incompatible with WriteLock.
-4. (set 2) WriteLock: Exclusive. Modify the node. Incompatible with ReadLock and other WriteLocks.
-5. (set 3) ParentLock: Exclusive. Have parent adopt/delete maximum foster child from the node.
-*/
-
-typedef enum{
- BtLockAccess,
- BtLockDelete,
- BtLockRead,
- BtLockWrite,
- BtLockParent
-}BtLock;
-
-// Define the length of the page and key pointers
-
-#define BtId 6
-
-// Page key slot definition.
-
-// If BT_maxbits is 15 or less, you can save 4 bytes
-// for each key stored by making the first two uints
-// into ushorts. You can also save 4 bytes by removing
-// the tod field from the key.
-
-// Keys are marked dead, but remain on the page until
-// it cleanup is called. The fence key (highest key) for
-// the page is always present, even after cleanup.
-
-typedef struct {
- uint off:BT_maxbits; // page offset for key start
- uint dead:1; // set for deleted key
- uint tod; // time-stamp for key
- unsigned char id[BtId]; // id associated with key
-} BtSlot;
-
-// The key structure occupies space at the upper end of
-// each page. It's a length byte followed by the value
-// bytes.
-
-typedef struct {
- unsigned char len;
- unsigned char key[1];
-} *BtKey;
-
-// The first part of an index page.
-// It is immediately followed
-// by the BtSlot array of keys.
-
-typedef struct Page {
- uint cnt; // count of keys in page
- uint act; // count of active keys
- uint min; // next key offset
- uint foster; // count of foster children
- unsigned char bits; // page size in bits
- unsigned char lvl:6; // level of page
- unsigned char kill:1; // page is being deleted
- unsigned char dirty:1; // page needs to be cleaned
- unsigned char right[BtId]; // page number to right
-} *BtPage;
-
-// mode & definition for latch table implementation
-
-enum {
- Write = 1,
- Pending = 2,
- Share = 4
-} LockMode;
-
-// latch table lock structure
-
-// exclusive is set for write access
-// share is count of read accessors
-// grant write lock when share == 0
-
-typedef struct {
- volatile uint exclusive:1;
- volatile uint request:1;
- volatile uint share:30;
-} BtLatch;
-
-typedef struct {
- BtLatch readwr[1]; // read/write page lock
- BtLatch access[1]; // Access Intent/Page delete
- BtLatch parent[1]; // adoption of foster children
-} BtLatchSet;
-
-// The memory mapping pool table buffer manager entry
-
-typedef struct {
- unsigned long long int lru; // number of times accessed
- uid basepage; // mapped base page number
- char *map; // mapped memory pointer
- uint pin; // mapped page pin counter
- uint slot; // slot index in this array
- void *hashprev; // previous pool entry for the same hash idx
- void *hashnext; // next pool entry for the same hash idx
-#ifndef unix
- HANDLE hmap;
-#endif
-// array of page latch sets, one for each page in map segment
- BtLatchSet pagelatch[0];
-} BtPool;
-
-// The object structure for Btree access
-
-typedef struct {
- uint page_size; // page size
- uint page_bits; // page size in bits
- uint seg_bits; // seg size in pages in bits
- uint mode; // read-write mode
-#ifdef unix
- int idx;
- char *pooladvise; // bit maps for pool page advisements
-#else
- HANDLE idx;
-#endif
- uint poolcnt; // highest page pool node in use
- uint poolmax; // highest page pool node allocated
- uint poolmask; // total size of pages in mmap segment - 1
- uint hashsize; // size of Hash Table for pool entries
- volatile uint evicted; // last evicted hash table slot
- ushort *hash; // hash table of pool entries
- BtLatch *latch; // latches for hash table slots
- char *nodes; // memory pool page segments
-} BtMgr;
-
-typedef struct {
- BtMgr *mgr; // buffer manager for thread
- BtPage temp; // temporary frame buffer (memory mapped/file IO)
- BtPage alloc; // frame buffer for alloc page ( page 0 )
- BtPage cursor; // cached frame for start/next (never mapped)
- BtPage frame; // spare frame for the page split (never mapped)
- BtPage zero; // page frame for zeroes at end of file
- BtPage page; // current page
- uid page_no; // current page number
- uid cursor_page; // current cursor page number
- unsigned char *mem; // frame, cursor, page memory buffer
- int err; // last error
-} BtDb;
-
-typedef enum {
- BTERR_ok = 0,
- BTERR_struct,
- BTERR_ovflw,
- BTERR_lock,
- BTERR_map,
- BTERR_wrt,
- BTERR_hash
-} BTERR;
-
-// B-Tree functions
-extern void bt_close (BtDb *bt);
-extern BtDb *bt_open (BtMgr *mgr);
-extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod);
-extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
-extern uid bt_findkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_nextkey (BtDb *bt, uint slot);
-
-// manager functions
-bt_mgr (char *name, uint mode, uint bits, uint poolsize, uint segsize, uint hashsize);
-void bt_mgrclose (BtMgr *mgr);
-
-// Helper functions to return cursor slot values
-
-extern BtKey bt_key (BtDb *bt, uint slot);
-extern uid bt_uid (BtDb *bt, uint slot);
-extern uint bt_tod (BtDb *bt, uint slot);
-
-// BTree page number constants
-#define ALLOC_page 0
-#define ROOT_page 1
-#define LEAF_page 2
-
-// Number of levels to create in a new BTree
-
-#define MIN_lvl 2
-
-// The page is allocated from low and hi ends.
-// The key offsets and row-id's are allocated
-// from the bottom, while the text of the key
-// is allocated from the top. When the two
-// areas meet, the page is split into two.
-
-// A key consists of a length byte, two bytes of
-// index number (0 - 65534), and up to 253 bytes
-// of key value. Duplicate keys are discarded.
-// Associated with each key is a 48 bit row-id.
-
-// The b-tree root is always located at page 1.
-// The first leaf page of level zero is always
-// located on page 2.
-
-// When to root page fills, it is split in two and
-// the tree height is raised by a new root at page
-// one with two keys.
-
-// Deleted keys are marked with a dead bit until
-// page cleanup The fence key for a node is always
-// present, even after deletion and cleanup.
-
-// Groups of pages called segments from the btree are
-// cached with memory mapping. A hash table is used to keep
-// track of the cached segments. This behaviour is controlled
-// by the cache block size parameter to bt_open.
-
-// To achieve maximum concurrency one page is locked at a time
-// as the tree is traversed to find leaf key in question.
-
-// An adoption traversal leaves the parent node locked as the
-// tree is traversed to the level in quesiton.
-
-// Page 0 is dedicated to lock for new page extensions,
-// and chains empty pages together for reuse.
-
-// Empty pages are chained together through the ALLOC page and reused.
-
-// Access macros to address slot and key values from the page
-
-#define slotptr(page, slot) (((BtSlot *)(page+1)) + (slot-1))
-#define keyptr(page, slot) ((BtKey)((unsigned char*)(page) + slotptr(page, slot)->off))
-
-void bt_putid(unsigned char *dest, uid id)
-{
-int i = BtId;
-
- while( i-- )
- dest[i] = (unsigned char)id, id >>= 8;
-}
-
-uid bt_getid(unsigned char *src)
-{
-uid id = 0;
-int i;
-
- for( i = 0; i < BtId; i++ )
- id <<= 8, id |= *src++;
-
- return id;
-}
-
-void bt_mgrclose (BtMgr *mgr)
-{
-BtPool *pool;
-uint slot;
-
- // release mapped pages
- // note that slot zero is never used
-
- for( slot = 1; slot < mgr->poolmax; slot++ ) {
- pool = (BtPool *)(mgr->nodes + slot * (sizeof(BtPool) + (mgr->poolmask + 1) * sizeof(BtLatchSet)));
- if( pool->slot )
-#ifdef unix
- munmap (pool->map, (mgr->poolmask+1) << mgr->page_bits);
-#else
- {
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
- }
-#endif
- }
-
-#ifdef unix
- close (mgr->idx);
- free (mgr->nodes);
- free (mgr->hash);
- free (mgr->latch);
- free (mgr->pooladvise);
- free (mgr);
-#else
- FlushFileBuffers(mgr->idx);
- CloseHandle(mgr->idx);
- GlobalFree (mgr->nodes);
- GlobalFree (mgr->hash);
- GlobalFree (mgr->latch);
- GlobalFree (mgr);
-#endif
-}
-
-// close and release memory
-
-void bt_close (BtDb *bt)
-{
-#ifdef unix
- if ( bt->mem )
- free (bt->mem);
-#else
- if ( bt->mem)
- VirtualFree (bt->mem, 0, MEM_RELEASE);
-#endif
- free (bt);
-}
-
-// open/create new btree buffer manager
-
-// call with file_name, BT_openmode, bits in page size (e.g. 16),
-// size of mapped page pool (e.g. 8192)
-
-BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolmax, uint segsize, uint hashsize)
-{
-uint lvl, attr, cacheblk, last;
-BtPage alloc;
-int lockmode;
-off64_t size;
-uint amt[1];
-BtMgr* mgr;
-BtKey key;
-
-#ifndef unix
-SYSTEM_INFO sysinfo[1];
-#endif
-
- // determine sanity of page size and buffer pool
-
- if( bits > BT_maxbits )
- bits = BT_maxbits;
- else if( bits < BT_minbits )
- bits = BT_minbits;
-
- if( !poolmax )
- return NULL; // must have buffer pool
-
-#ifdef unix
- mgr = calloc (1, sizeof(BtMgr));
-
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
- lockmode = 1;
- break;
-
- case BT_ro:
- default:
- mgr->idx = open ((char*)name, O_RDONLY);
- lockmode = 0;
- break;
- }
- if( mgr->idx == -1 )
- return free(mgr), NULL;
-
- cacheblk = 4096; // minimum mmap segment size for unix
-
-#else
- mgr = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtMgr));
- attr = FILE_ATTRIBUTE_NORMAL;
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
- lockmode = 1;
- break;
-
- case BT_ro:
- default:
- mgr->idx = CreateFile(name, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, attr, NULL);
- lockmode = 0;
- break;
- }
- if( mgr->idx == INVALID_HANDLE_VALUE )
- return GlobalFree(mgr), NULL;
-
- // normalize cacheblk to multiple of sysinfo->dwAllocationGranularity
- GetSystemInfo(sysinfo);
- cacheblk = sysinfo->dwAllocationGranularity;
-#endif
-
-#ifdef unix
- alloc = malloc (BT_maxpage);
- *amt = 0;
-
- // read minimum page size to get root info
-
- if( size = lseek (mgr->idx, 0L, 2) ) {
- if( pread(mgr->idx, alloc, BT_minpage, 0) == BT_minpage )
- bits = alloc->bits;
- else
- return free(mgr), free(alloc), NULL;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#else
- alloc = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
- size = GetFileSize(mgr->idx, amt);
-
- if( size || *amt ) {
- if( !ReadFile(mgr->idx, (char *)alloc, BT_minpage, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- bits = alloc->bits;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- mgr->page_size = 1 << bits;
- mgr->page_bits = bits;
-
- mgr->poolmax = poolmax;
- mgr->mode = mode;
-
- if( cacheblk < mgr->page_size )
- cacheblk = mgr->page_size;
-
- // mask for partial memmaps
-
- mgr->poolmask = (cacheblk >> bits) - 1;
-
- // see if requested size of pages per memmap is greater
-
- if( (1 << segsize) > mgr->poolmask )
- mgr->poolmask = (1 << segsize) - 1;
-
- mgr->seg_bits = 0;
-
- while( (1 << mgr->seg_bits) <= mgr->poolmask )
- mgr->seg_bits++;
-
- mgr->hashsize = hashsize;
-
-#ifdef unix
- mgr->nodes = calloc (poolmax, (sizeof(BtPool) + (mgr->poolmask + 1) * sizeof(BtLatchSet)));
- mgr->hash = calloc (hashsize, sizeof(ushort));
- mgr->latch = calloc (hashsize, sizeof(BtLatch));
- mgr->pooladvise = calloc (poolmax, (mgr->poolmask + 1) / 8);
-#else
- mgr->nodes = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, poolmax * (sizeof(BtPool) + (mgr->poolmask + 1) * sizeof(BtLatchSet)));
- mgr->hash = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(ushort));
- mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtLatch));
-#endif
-
- if( size || *amt )
- goto mgrxit;
-
- // initializes an empty b-tree with root page and page of leaves
-
- memset (alloc, 0, 1 << bits);
- bt_putid(alloc->right, MIN_lvl+1);
- alloc->bits = mgr->page_bits;
-
-#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- memset (alloc, 0, 1 << bits);
- alloc->bits = mgr->page_bits;
-
- for( lvl=MIN_lvl; lvl--; ) {
- slotptr(alloc, 1)->off = mgr->page_size - 3;
- bt_putid(slotptr(alloc, 1)->id, lvl ? MIN_lvl - lvl + 1 : 0); // next(lower) page number
- key = keyptr(alloc, 1);
- key->len = 2; // create stopper key
- key->key[0] = 0xff;
- key->key[1] = 0xff;
- alloc->min = mgr->page_size - 3;
- alloc->lvl = lvl;
- alloc->cnt = 1;
- alloc->act = 1;
-#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
- // create empty page area by writing last page of first
- // segment area (other pages are zeroed by O/S)
-
- if( mgr->poolmask ) {
- memset(alloc, 0, mgr->page_size);
- last = mgr->poolmask;
-
- while( last < MIN_lvl + 1 )
- last += mgr->poolmask + 1;
-
-#ifdef unix
- pwrite(mgr->idx, alloc, mgr->page_size, last << mgr->page_bits);
-#else
- SetFilePointer (mgr->idx, last << mgr->page_bits, NULL, FILE_BEGIN);
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
-mgrxit:
-#ifdef unix
- free (alloc);
-#else
- VirtualFree (alloc, 0, MEM_RELEASE);
-#endif
- return mgr;
-}
-
-// open BTree access method
-// based on buffer manager
-
-BtDb *bt_open (BtMgr *mgr)
-{
-BtDb *bt = malloc (sizeof(*bt));
-
- memset (bt, 0, sizeof(*bt));
- bt->mgr = mgr;
-#ifdef unix
- bt->mem = malloc (3 *mgr->page_size);
-#else
- bt->mem = VirtualAlloc(NULL, 3 * mgr->page_size, MEM_COMMIT, PAGE_READWRITE);
-#endif
- bt->frame = (BtPage)bt->mem;
- bt->zero = (BtPage)(bt->mem + 1 * mgr->page_size);
- bt->cursor = (BtPage)(bt->mem + 2 * mgr->page_size);
- return bt;
-}
-
-// compare two keys, returning > 0, = 0, or < 0
-// as the comparison value
-
-int keycmp (BtKey key1, unsigned char *key2, uint len2)
-{
-uint len1 = key1->len;
-int ans;
-
- if( ans = memcmp (key1->key, key2, len1 > len2 ? len2 : len1) )
- return ans;
-
- if( len1 > len2 )
- return 1;
- if( len1 < len2 )
- return -1;
-
- return 0;
-}
-
-// Latch Manager
-
-// wait until write lock mode is clear
-// and add 1 to the share count
-
-void bt_readlock(BtLatch *latch)
-{
- do {
- // see if exclusive request is pending, or granted
-
- if( !(volatile int)latch->request && !(volatile int)latch->exclusive ) {
- // add one to counter, check write bit
-#ifdef unix
- if( ~__sync_fetch_and_add((volatile int *)latch, Share) & Write )
- return;
-#else
- if( ~_InterlockedExchangeAdd((volatile int *)latch, Share) & Write )
- return;
-#endif
- // didn't get latch, reduce counter by one
-
-#ifdef unix
- __sync_fetch_and_add((volatile int *)latch, -Share);
-#else
- _InterlockedExchangeAdd ((volatile int *)latch, -Share);
-#endif
- }
-
- // and yield
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- } while( 1 );
-}
-
-// wait for other read and write latches to relinquish
-
-void bt_writelock(BtLatch *latch)
-{
-int prev;
-
- do {
- // set exclusive access pending
-
-#ifdef unix
- __sync_fetch_and_or((int *)latch, Pending);
-#else
- _InterlockedOr((int *)latch, Pending);
-#endif
-
- // see if we can get write access
- // with no readers
-#ifdef unix
- prev = __sync_fetch_and_or((volatile int *)latch, Write);
-#else
- prev = _InterlockedOr((volatile int *)latch, Write);
-#endif
-
- // did we get exclusive access?
- // if so, clear write pending
-
- if( !(prev & ~Pending) ) {
-#ifdef unix
- __sync_fetch_and_and((volatile int *)latch, ~Pending);
-#else
- _InterlockedAnd((volatile int *)latch, ~Pending);
-#endif
- return;
- }
-
- // reset our Write mode if it was clear before
-
- if( !(prev & Write) ) {
-#ifdef unix
- __sync_fetch_and_and((volatile int *)latch, ~Write);
-#else
- _InterlockedAnd((volatile int *)latch, ~Write);
-#endif
- }
-
- // otherwise yield
-
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- } while( 1 );
-}
-
-// try to obtain write lock
-
-// return 1 if obtained,
-// 0 if already write locked
-
-int bt_writetry(BtLatch *latch)
-{
-int prev;
-
- // see if we can get write access
- // with no readers
-#ifdef unix
- prev = __sync_fetch_and_or((volatile int *)latch, Write);
-#else
- prev = _InterlockedOr((volatile int *)latch, Write);
-#endif
-
- // did we get exclusive access?
- // if so, return OK
-
- if( !(prev & ~Pending) )
- return 1;
-
- // reset our Write mode if it was clear before
-
- if( !(prev & Write) ) {
-#ifdef unix
- __sync_fetch_and_and((volatile int *)latch, ~Write);
-#else
- _InterlockedAnd((volatile int *)latch, ~Write);
-#endif
- }
- return 0;
-}
-
-// clear write mode
-
-void bt_releasewrite(BtLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_and((int *)latch, ~Write);
-#else
- _InterlockedAnd ((int *)latch, ~Write);
-#endif
-}
-
-// decrement reader count
-
-void bt_releaseread(BtLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_add((int *)latch, -Share);
-#else
- _InterlockedExchangeAdd((int *)latch, -Share);
-#endif
-}
-
-// Buffer Pool mgr
-
-// find segment in pool
-// must be called with hashslot idx locked
-// return NULL if not there
-// otherwise return node
-
-BtPool *bt_findpool(BtDb *bt, uid page_no, uint idx)
-{
-BtPool *pool;
-uint slot;
-
- // compute start of hash chain in pool
-
- if( slot = bt->mgr->hash[idx] )
- pool = (BtPool *)(bt->mgr->nodes + slot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
- else
- return NULL;
-
- page_no &= ~bt->mgr->poolmask;
-
- while( pool->basepage != page_no )
- if( pool = pool->hashnext )
- continue;
- else
- return NULL;
-
- return pool;
-}
-
-// add segment to hash table
-
-void bt_linkhash(BtDb *bt, BtPool *pool, uid page_no, int idx)
-{
-BtPool *node;
-uint slot;
-
- pool->hashprev = pool->hashnext = NULL;
- pool->basepage = page_no & ~bt->mgr->poolmask;
- pool->lru = 1;
-
- if( slot = bt->mgr->hash[idx] ) {
- node = (BtPool *)(bt->mgr->nodes + slot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
- pool->hashnext = node;
- node->hashprev = pool;
- }
-
- bt->mgr->hash[idx] = pool->slot;
-}
-
-// find best segment to evict from buffer pool
-
-BtPool *bt_findlru (BtDb *bt, uint hashslot)
-{
-unsigned long long int target = ~0LL;
-BtPool *pool = NULL, *node;
-
- if( !hashslot )
- return NULL;
-
- node = (BtPool *)(bt->mgr->nodes + hashslot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
-
- // scan pool entries under hash table slot
-
- do {
- if( node->pin )
- continue;
- if( node->lru > target )
- continue;
- target = node->lru;
- pool = node;
- } while( node = node->hashnext );
-
- return pool;
-}
-
-// map new buffer pool segment to virtual memory
-
-BTERR bt_mapsegment(BtDb *bt, BtPool *pool, uid page_no)
-{
-off64_t off = (page_no & ~bt->mgr->poolmask) << bt->mgr->page_bits;
-off64_t limit = off + ((bt->mgr->poolmask+1) << bt->mgr->page_bits);
-int flag;
-
-#ifdef unix
- flag = PROT_READ | ( bt->mgr->mode == BT_ro ? 0 : PROT_WRITE );
- pool->map = mmap (0, (bt->mgr->poolmask+1) << bt->mgr->page_bits, flag, MAP_SHARED, bt->mgr->idx, off);
- if( pool->map == MAP_FAILED )
- return bt->err = BTERR_map;
- // clear out madvise issued bits
- memset (bt->mgr->pooladvise + pool->slot * (bt->mgr->poolmask + 1) / 8, 0, (bt->mgr->poolmask + 1)/8);
-#else
- flag = ( bt->mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
- pool->hmap = CreateFileMapping(bt->mgr->idx, NULL, flag, (DWORD)(limit >> 32), (DWORD)limit, NULL);
- if( !pool->hmap )
- return bt->err = BTERR_map;
-
- flag = ( bt->mgr->mode == BT_ro ? FILE_MAP_READ : FILE_MAP_WRITE );
- pool->map = MapViewOfFile(pool->hmap, flag, (DWORD)(off >> 32), (DWORD)off, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
- if( !pool->map )
- return bt->err = BTERR_map;
-#endif
- return bt->err = 0;
-}
-
-// find or place requested page in segment-pool
-// return pool table entry, incrementing pin
-
-BtPool *bt_pinpage(BtDb *bt, uid page_no)
-{
-BtPool *pool, *node, *next;
-uint slot, idx, victim;
-BtLatchSet *set;
-
- // lock hash table chain
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx]);
-
- // look up in hash table
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releaseread (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // upgrade to write lock
-
- bt_releaseread (&bt->mgr->latch[idx]);
- bt_writelock (&bt->mgr->latch[idx]);
-
- // try to find page in pool with write lock
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // allocate a new pool node
- // and add to hash table
-
-#ifdef unix
- slot = __sync_fetch_and_add(&bt->mgr->poolcnt, 1);
-#else
- slot = _InterlockedIncrement (&bt->mgr->poolcnt) - 1;
-#endif
-
- if( ++slot < bt->mgr->poolmax ) {
- pool = (BtPool *)(bt->mgr->nodes + slot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
- pool->slot = slot;
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-
- // pool table is full
- // find best pool entry to evict
-
-#ifdef unix
- __sync_fetch_and_add(&bt->mgr->poolcnt, -1);
-#else
- _InterlockedDecrement (&bt->mgr->poolcnt);
-#endif
-
- while( 1 ) {
-#ifdef unix
- victim = __sync_fetch_and_add(&bt->mgr->evicted, 1);
-#else
- victim = _InterlockedIncrement (&bt->mgr->evicted) - 1;
-#endif
- victim %= bt->mgr->hashsize;
-
- // try to get write lock
- // skip entry if not obtained
-
- if( !bt_writetry (&bt->mgr->latch[victim]) )
- continue;
-
- // if cache entry is empty
- // or no slots are unpinned
- // skip this entry
-
- if( !(pool = bt_findlru(bt, bt->mgr->hash[victim])) ) {
- bt_releasewrite (&bt->mgr->latch[victim]);
- continue;
- }
-
- // unlink victim pool node from hash table
-
- if( node = pool->hashprev )
- node->hashnext = pool->hashnext;
- else if( node = pool->hashnext )
- bt->mgr->hash[victim] = node->slot;
- else
- bt->mgr->hash[victim] = 0;
-
- if( node = pool->hashnext )
- node->hashprev = pool->hashprev;
-
- bt_releasewrite (&bt->mgr->latch[victim]);
-
- // remove old file mapping
-#ifdef unix
- munmap (pool->map, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
-#else
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
-#endif
- pool->map = NULL;
-
- // create new pool mapping
- // and link into hash table
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-}
-
-// place write, read, or parent lock on requested page_no.
-// pin to buffer pool and return page pointer
-
-BTERR bt_lockpage(BtDb *bt, uid page_no, BtLock mode, BtPage *pageptr)
-{
-BtLatchSet *set;
-BtPool *pool;
-uint subpage;
-BtPage page;
-
- // find/create maping in pool table
- // and pin our pool slot
-
- if( pool = bt_pinpage(bt, page_no) )
- subpage = (uint)(page_no & bt->mgr->poolmask); // page within mapping
- else
- return bt->err;
-
- set = pool->pagelatch + subpage;
- page = (BtPage)(pool->map + (subpage << bt->mgr->page_bits));
-#ifdef unix
- {
- uint idx = subpage / 8;
- uint bit = subpage % 8;
-
- if( !((bt->mgr->pooladvise + pool->slot * (bt->mgr->poolmask + 1)/8)[idx] >> bit) & 1 ) {
- madvise (page, bt->mgr->page_size, MADV_WILLNEED);
- (bt->mgr->pooladvise + pool->slot * (bt->mgr->poolmask + 1)/8)[idx] |= 1 << bit;
- }
- }
-#endif
-
- switch( mode ) {
- case BtLockRead:
- bt_readlock (set->readwr);
- break;
- case BtLockWrite:
- bt_writelock (set->readwr);
- break;
- case BtLockAccess:
- bt_readlock (set->access);
- break;
- case BtLockDelete:
- bt_writelock (set->access);
- break;
- case BtLockParent:
- bt_writelock (set->parent);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
- if( pageptr )
- *pageptr = page;
-
- return bt->err = 0;
-}
-
-// remove write, read, or parent lock on requested page_no.
-
-BTERR bt_unlockpage(BtDb *bt, uid page_no, BtLock mode)
-{
-uint subpage, idx;
-BtLatchSet *set;
-BtPool *pool;
-
- // since page is pinned
- // it should still be in the buffer pool
- // and is in no danger of being a victim for reuse
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx]);
-
- if( pool = bt_findpool(bt, page_no, idx) )
- subpage = (uint)(page_no & bt->mgr->poolmask);
- else
- return bt->err = BTERR_hash;
-
- bt_releaseread (&bt->mgr->latch[idx]);
- set = pool->pagelatch + subpage;
-
- switch( mode ) {
- case BtLockRead:
- bt_releaseread (set->readwr);
- break;
- case BtLockWrite:
- bt_releasewrite (set->readwr);
- break;
- case BtLockAccess:
- bt_releaseread (set->access);
- break;
- case BtLockDelete:
- bt_releasewrite (set->access);
- break;
- case BtLockParent:
- bt_releasewrite (set->parent);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, -1);
-#else
- _InterlockedDecrement (&pool->pin);
-#endif
- return bt->err = 0;
-}
-
-// deallocate a deleted page
-// place on free chain out of allocator page
-
-BTERR bt_freepage(BtDb *bt, uid page_no)
-{
- // obtain delete lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- // obtain write lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // lock allocation page
-
- if ( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return bt->err;
-
- // store chain in second right
- bt_putid(bt->temp->right, bt_getid(bt->alloc[1].right));
- bt_putid(bt->alloc[1].right, page_no);
-
- // unlock page zero
-
- if( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return bt->err;
-
- // remove write lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // remove delete lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockDelete) )
- return bt->err;
-
- return 0;
-}
-
-// allocate a new page and write page into it
-
-uid bt_newpage(BtDb *bt, BtPage page)
-{
-uid new_page;
-BtPage pmap;
-int reuse;
-
- // lock page zero
-
- if ( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return 0;
-
- // use empty chain first
- // else allocate empty page
-
- if( new_page = bt_getid(bt->alloc[1].right) ) {
- if( bt_lockpage (bt, new_page, BtLockWrite, &bt->temp) )
- return 0;
- bt_putid(bt->alloc[1].right, bt_getid(bt->temp->right));
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
- reuse = 1;
- } else {
- new_page = bt_getid(bt->alloc->right);
- bt_putid(bt->alloc->right, new_page+1);
- reuse = 0;
- }
-#ifdef unix
- if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
-
- // if writing first page of pool block, zero last page in the block
-
- if ( !reuse && bt->mgr->poolmask > 0 && (new_page & bt->mgr->poolmask) == 0 )
- {
- // use zero buffer to write zeros
- memset(bt->zero, 0, bt->mgr->page_size);
- if ( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->poolmask) << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
- }
-#else
- // bring new page into pool and copy page.
- // this will extend the file into the new pages.
-
- if( bt_lockpage(bt, new_page, BtLockWrite, &pmap) )
- return 0;
-
- memcpy(pmap, page, bt->mgr->page_size);
-
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
-#endif
- // unlock page zero
-
- if ( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return 0;
-
- return new_page;
-}
-
-// find slot in page for given key at a given level
-
-int bt_findslot (BtDb *bt, unsigned char *key, uint len)
-{
-uint diff, higher = bt->page->cnt, low = 1, slot;
-
- // low is the lowest candidate, higher is already
- // tested as .ge. the given key, loop ends when they meet
-
- while( diff = higher - low ) {
- slot = low + ( diff >> 1 );
- if( keycmp (keyptr(bt->page, slot), key, len) < 0 )
- low = slot + 1;
- else
- higher = slot;
- }
-
- return higher;
-}
-
-// find and load page at given level for given key
-// leave page rd or wr locked as requested
-
-int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, uint lock)
-{
-uid page_no = ROOT_page, prevpage = 0;
-uint drill = 0xff, slot;
-uint mode, prevmode;
-
- // start at root of btree and drill down
-
- do {
- // determine lock mode of drill level
- mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead;
-
- bt->page_no = page_no;
-
- // obtain access lock using lock chaining with Access mode
-
- if( page_no > ROOT_page )
- if( bt_lockpage(bt, page_no, BtLockAccess, NULL) )
- return 0;
-
- if( prevpage )
- if( bt_unlockpage(bt, prevpage, prevmode) )
- return 0;
-
- // obtain read lock using lock chaining
- // and pin page contents
-
- if( bt_lockpage(bt, page_no, mode, &bt->page) )
- return 0;
-
- if( page_no > ROOT_page )
- if( bt_unlockpage(bt, page_no, BtLockAccess) )
- return 0;
-
- // re-read and re-lock root after determining actual level of root
-
- if( bt->page_no == ROOT_page )
- if( bt->page->lvl != drill) {
- drill = bt->page->lvl;
-
- if( lock == BtLockWrite && drill == lvl )
- if( bt_unlockpage(bt, page_no, mode) )
- return 0;
- else
- continue;
- }
-
- // if page is being deleted,
- // move back to preceeding page
-
- if( bt->page->kill ) {
- page_no = bt_getid (bt->page->right);
- continue;
- }
-
- // find key on page at this level
- // and descend to requested level
-
- slot = bt_findslot (bt, key, len);
-
- // is this slot a foster child?
-
- if( slot <= bt->page->cnt - bt->page->foster )
- if( drill == lvl )
- return slot;
- else
- drill--;
-
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
- continue;
- else
- return bt->err = BTERR_struct, 0;
-
- // continue down / right using overlapping locks
- // to protect pages being killed or split.
-
- prevmode = mode;
- prevpage = bt->page_no;
- page_no = bt_getid(slotptr(bt->page, slot)->id);
- } while( page_no );
-
- // return error on end of chain
-
- bt->err = BTERR_struct;
- return 0; // return error
-}
-
-// find and delete key on page by marking delete flag bit
-// when page becomes empty, delete it from the btree
-
-BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl)
-{
-unsigned char leftkey[256], rightkey[256];
-uid page_no, right;
-uint slot, tod;
-BtKey ptr;
-
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // if key is found delete it, otherwise ignore request
-
- if( !keycmp (ptr, key, len) )
- if( slotptr(bt->page, slot)->dead == 0 ) {
- slotptr(bt->page,slot)->dead = 1;
- if( slot < bt->page->cnt )
- bt->page->dirty = 1;
- bt->page->act--;
- }
-
- // return if page is not empty, or it has no right sibling
-
- right = bt_getid(bt->page->right);
- page_no = bt->page_no;
-
- if( !right || bt->page->act )
- return bt_unlockpage(bt, page_no, BtLockWrite);
-
- // obtain Parent lock over write lock
-
- if( bt_lockpage(bt, page_no, BtLockParent, NULL) )
- return bt->err;
-
- // cache copy of key to delete
-
- ptr = keyptr(bt->page, bt->page->cnt);
- memcpy(leftkey, ptr, ptr->len + 1);
-
- // lock and map right page
-
- if ( bt_lockpage(bt, right, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // pull contents of next page into current empty page
- memcpy (bt->page, bt->temp, bt->mgr->page_size);
-
- // cache copy of key to update
- ptr = keyptr(bt->temp, bt->temp->cnt);
- memcpy(rightkey, ptr, ptr->len + 1);
-
- // Mark right page as deleted and point it to left page
- // until we can post updates at higher level.
-
- bt_putid(bt->temp->right, page_no);
- bt->temp->kill = 1;
- bt->temp->cnt = 0;
-
- if( bt_unlockpage(bt, right, BtLockWrite) )
- return bt->err;
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // delete old lower key to consolidated node
-
- if( bt_deletekey (bt, leftkey + 1, *leftkey, lvl + 1) )
- return bt->err;
-
- // redirect higher key directly to consolidated node
-
- if( slot = bt_loadpage (bt, rightkey+1, *rightkey, lvl+1, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // since key already exists, update id
-
- if( keycmp (ptr, rightkey+1, *rightkey) )
- return bt->err = BTERR_struct;
-
- slotptr(bt->page, slot)->dead = 0;
- bt_putid(slotptr(bt->page,slot)->id, page_no);
- bt_unlockpage(bt, bt->page_no, BtLockWrite);
-
- // obtain write lock and
- // add right block to free chain
-
- if( bt_freepage (bt, right) )
- return bt->err;
-
- // remove ParentModify lock
-
- if( bt_unlockpage(bt, page_no, BtLockParent) )
- return bt->err;
-
- return 0;
-}
-
-// find key in leaf level and return row-id
-
-uid bt_findkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-BtKey ptr;
-uid id;
-
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- ptr = keyptr(bt->page, slot);
- else
- return 0;
-
- // if key exists, return row-id
- // otherwise return 0
-
- if( ptr->len == len && !memcmp (ptr->key, key, len) )
- id = bt_getid(slotptr(bt->page,slot)->id);
- else
- id = 0;
-
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
-
- return id;
-}
-
-// check page for space available,
-// clean if necessary and return
-// 0 - page needs splitting
-// 1 - go ahead
-
-uint bt_cleanpage(BtDb *bt, uint amt)
-{
-uint nxt = bt->mgr->page_size;
-BtPage page = bt->page;
-uint cnt = 0, idx = 0;
-uint max = page->cnt;
-BtKey key;
-
- if( page->min >= (max+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- // skip cleanup if nothing to reclaim
-
- if( !page->dirty )
- return 0;
-
- memcpy (bt->frame, page, bt->mgr->page_size);
-
- // skip page info and set rest of page to zero
-
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- page->dirty = 0;
- page->act = 0;
-
- // try cleaning up page first
-
- while( cnt++ < max ) {
- // always leave fence key and foster children in list
- if( cnt < max - page->foster && slotptr(bt->frame,cnt)->dead )
- continue;
-
- // copy key
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
-
- // copy slot
- memcpy(slotptr(page, ++idx)->id, slotptr(bt->frame, cnt)->id, BtId);
- if( !(slotptr(page, idx)->dead = slotptr(bt->frame, cnt)->dead) )
- page->act++;
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // see if page has enough space now, or does it need splitting?
-
- if( page->min >= (idx+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- return 0;
-}
-
-// add key to page
-// return with page unlocked
-
-BTERR bt_addkeytopage (BtDb *bt, uint slot, unsigned char *key, uint len, uid id, uint tod)
-{
-BtPage page = bt->page;
-uint idx;
-
- // calculate next available slot and copy key into page
-
- page->min -= len + 1;
- ((unsigned char *)page)[page->min] = len;
- memcpy ((unsigned char *)page + page->min +1, key, len );
-
- for( idx = slot; idx < page->cnt; idx++ )
- if( slotptr(page, idx)->dead )
- break;
-
- // now insert key into array before slot
- // preserving the fence slot
-
- if( idx == page->cnt )
- idx++, page->cnt++;
-
- page->act++;
-
- while( idx > slot )
- *slotptr(page, idx) = *slotptr(page, idx -1), idx--;
-
- bt_putid(slotptr(page,slot)->id, id);
- slotptr(page, slot)->off = page->min;
- slotptr(page, slot)->tod = tod;
- slotptr(page, slot)->dead = 0;
-
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
-}
-
-// split the root and raise the height of the btree
-
-BTERR bt_splitroot(BtDb *bt, uid right)
-{
-uint nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-BtPage root = bt->page;
-uid new_page;
-BtKey key;
-
- // Obtain an empty page to use, and copy the left page
- // contents into it from the root. Strip foster child key.
- // (it's the stopper key)
-
- root->act--;
- root->cnt--;
- root->foster--;
-
- // Save left fence key.
-
- key = keyptr(root, root->cnt);
- memcpy (fencekey, key, key->len + 1);
-
- // copy the lower keys into a new left page
-
- if( !(new_page = bt_newpage(bt, root)) )
- return bt->err;
-
- // preserve the page info at the bottom
- // and set rest of the root to zero
-
- memset (root+1, 0, bt->mgr->page_size - sizeof(*root));
-
- // insert left fence key on empty newroot page
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 1)->id, new_page);
- slotptr(root, 1)->off = nxt;
-
- // insert stopper key on newroot page
- // and increase the root height
-
- nxt -= 3;
- fencekey[0] = 2;
- fencekey[1] = 0xff;
- fencekey[2] = 0xff;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 2)->id, right);
- slotptr(root, 2)->off = nxt;
-
- bt_putid(root->right, 0);
- root->min = nxt; // reset lowest used offset and key count
- root->cnt = 2;
- root->act = 2;
- root->lvl++;
-
- // release root (bt->page)
-
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
-}
-
-// split already locked full node
-// return unlocked.
-
-BTERR bt_splitpage (BtDb *bt)
-{
-uint slot, cnt, idx, max, nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-uid page_no = bt->page_no;
-BtPage page = bt->page;
-uint tod = time(NULL);
-uint lvl = page->lvl;
-uid new_page, right;
-BtKey key;
-
- // initialize frame buffer
-
- memset (bt->frame, 0, bt->mgr->page_size);
- max = page->cnt - page->foster;
- tod = (uint)time(NULL);
- cnt = max / 2;
- idx = 0;
-
- // split higher half of keys to bt->frame
- // leaving foster children in the left node.
-
- while( cnt++ < max ) {
- key = keyptr(page, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)bt->frame + nxt, key, key->len + 1);
- memcpy(slotptr(bt->frame,++idx)->id, slotptr(page,cnt)->id, BtId);
- slotptr(bt->frame, idx)->tod = slotptr(page, cnt)->tod;
- slotptr(bt->frame, idx)->off = nxt;
- bt->frame->act++;
- }
-
- // transfer right link node
-
- if( page_no > ROOT_page ) {
- right = bt_getid (page->right);
- bt_putid(bt->frame->right, right);
- }
-
- bt->frame->bits = bt->mgr->page_bits;
- bt->frame->min = nxt;
- bt->frame->cnt = idx;
- bt->frame->lvl = lvl;
-
- // get new free page and write frame to it.
-
- if( !(new_page = bt_newpage(bt, bt->frame)) )
- return bt->err;
-
- // remember fence key for new page to add
- // as foster child
-
- key = keyptr(bt->frame, idx);
- memcpy (fencekey, key, key->len + 1);
-
- // update lower keys and foster children to continue in old page
-
- memcpy (bt->frame, page, bt->mgr->page_size);
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- nxt = bt->mgr->page_size;
- page->act = 0;
- cnt = 0;
- idx = 0;
-
- // assemble page of smaller keys
- // to remain in the old page
-
- while( cnt++ < max / 2 ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- // insert new foster child at beginning of the current foster children
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)page + nxt, fencekey, *fencekey + 1);
- bt_putid (slotptr(page,++idx)->id, new_page);
- slotptr(page, idx)->tod = tod;
- slotptr(page, idx)->off = nxt;
- page->foster++;
- page->act++;
-
- // continue with old foster child keys if any
-
- cnt = bt->frame->cnt - bt->frame->foster;
-
- while( cnt++ < bt->frame->cnt ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // link new right page
-
- bt_putid (page->right, new_page);
-
- // if current page is the root page, split it
-
- if( page_no == ROOT_page )
- return bt_splitroot (bt, new_page);
-
- // release wr lock on page
-
- if( bt_unlockpage (bt, page_no, BtLockWrite) )
- return bt->err;
-
- // obtain ParentModification lock for current page
- // to fix fence key and highest foster child on page
-
- if( bt_lockpage (bt, page_no, BtLockParent, NULL) )
- return bt->err;
-
- // get our highest foster child key to find in parent node
-
- if( bt_lockpage (bt, page_no, BtLockRead, &page) )
- return bt->err;
-
- key = keyptr(page, page->cnt);
- memcpy (fencekey, key, key->len+1);
-
- if( bt_unlockpage (bt, page_no, BtLockRead) )
- return bt->err;
-
-try_again:
-
- do {
- slot = bt_loadpage (bt, fencekey + 1, *fencekey, lvl + 1, BtLockWrite);
-
- if( !slot )
- return bt->err;
-
- // check if parent page has enough space for any possible key
-
- if( bt_cleanpage (bt, 256) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- } while( 1 );
-
- // see if we are still a foster child from another node
-
- if( bt_getid (slotptr(bt->page, slot)->id) != page_no ) {
- bt_unlockpage (bt, bt->page_no, BtLockWrite);
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- goto try_again;
- }
-
- // wait until readers from parent get their locks
-
- if( bt_lockpage (bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- if( bt_lockpage (bt, page_no, BtLockWrite, &page) )
- return bt->err;
-
- // switch parent fence key to foster child
-
- if( slotptr(page, page->cnt)->dead )
- slotptr(bt->page, slot)->dead = 1;
- else
- bt_putid (slotptr(bt->page, slot)->id, bt_getid(slotptr(page, page->cnt)->id));
-
- // remove highest foster child from our page
- // add our new fence key to parent
-
- page->cnt--;
- page->act--;
- page->foster--;
- page->dirty = 1;
- key = keyptr(page, page->cnt);
-
- if( bt_addkeytopage (bt, slot, key->key, key->len, page_no, tod) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockDelete) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockWrite) )
- return bt->err;
-
- return bt_unlockpage (bt, page_no, BtLockParent);
-}
-
-// Insert new key into the btree at leaf level.
-
-BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod)
-{
-uint slot, idx;
-BtPage page;
-BtKey ptr;
-
- while( 1 ) {
- if( slot = bt_loadpage (bt, key, len, 0, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- {
- if ( !bt->err )
- bt->err = BTERR_ovflw;
- return bt->err;
- }
-
- // if key already exists, update id and return
-
- page = bt->page;
-
- if( !keycmp (ptr, key, len) ) {
- slotptr(page, slot)->dead = 0;
- slotptr(page, slot)->tod = tod;
- bt_putid(slotptr(page,slot)->id, id);
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
- }
-
- // check if page has enough space
-
- if( bt_cleanpage (bt, len) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- }
-
- return bt_addkeytopage (bt, slot, key, len, id, tod);
-}
-
-// cache page of keys into cursor and return starting slot for given key
-
-uint bt_startkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-
- // cache page for retrieval
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- memcpy (bt->cursor, bt->page, bt->mgr->page_size);
- bt->cursor_page = bt->page_no;
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
-
- return slot;
-}
-
-// return next slot for cursor page
-// or slide cursor right into next page
-
-uint bt_nextkey (BtDb *bt, uint slot)
-{
-BtPage page;
-uid right;
-
- do {
- right = bt_getid(bt->cursor->right);
- while( slot++ < bt->cursor->cnt - bt->cursor->foster )
- if( slotptr(bt->cursor,slot)->dead )
- continue;
- else if( right || (slot < bt->cursor->cnt - bt->cursor->foster) )
- return slot;
- else
- break;
-
- if( !right )
- break;
-
- bt->cursor_page = right;
-
- if( bt_lockpage(bt, right, BtLockRead, &page) )
- return 0;
-
- memcpy (bt->cursor, page, bt->mgr->page_size);
-
- if ( bt_unlockpage(bt, right, BtLockRead) )
- return 0;
-
- slot = 0;
- } while( 1 );
-
- return bt->err = 0;
-}
-
-BtKey bt_key(BtDb *bt, uint slot)
-{
- return keyptr(bt->cursor, slot);
-}
-
-uid bt_uid(BtDb *bt, uint slot)
-{
- return bt_getid(slotptr(bt->cursor,slot)->id);
-}
-
-uint bt_tod(BtDb *bt, uint slot)
-{
- return slotptr(bt->cursor,slot)->tod;
-}
-
-
-#ifdef STANDALONE
-
-typedef struct {
- char type, idx;
- char *infile;
- BtMgr *mgr;
- int num;
-} ThreadArg;
-
-// standalone program to index file of keys
-// then list them onto std-out
-
-#ifdef unix
-void *index_file (void *arg)
-#else
-uint __stdcall index_file (void *arg)
-#endif
-{
-int line = 0, found = 0, cnt = 0;
-uid next, page_no = LEAF_page; // start on first page of leaves
-unsigned char key[256];
-ThreadArg *args = arg;
-int ch, len = 0, slot;
-time_t tod[1];
-BtPage page;
-BtKey ptr;
-BtDb *bt;
-FILE *in;
-
- bt = bt_open (args->mgr);
- time (tod);
-
- switch(args->type | 0x20)
- {
- case 'w':
- fprintf(stderr, "started indexing for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
-
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_insertkey (bt, key, len, line, *tod) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys\n", args->infile, line);
- break;
-
- case 'd':
- fprintf(stderr, "started deleting keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_deletekey (bt, key, len, 0) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for keys, %d \n", args->infile, line);
- break;
-
- case 'f':
- fprintf(stderr, "started finding keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_findkey (bt, key, len) )
- found++;
- else if( bt->err )
- fprintf(stderr, "Error %d Syserr %d Line: %d\n", bt->err, errno, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys, found %d\n", args->infile, line, found);
- break;
-
- case 's':
- len = key[0] = 0;
-
- fprintf(stderr, "started reading\n");
-
- if( slot = bt_startkey (bt, key, len) )
- slot--;
- else
- fprintf(stderr, "Error %d in StartKey. Syserror: %d\n", bt->err, errno), exit(0);
-
- while( slot = bt_nextkey (bt, slot) ) {
- ptr = bt_key(bt, slot);
- fwrite (ptr->key, ptr->len, 1, stdout);
- fputc ('\n', stdout);
- }
-
- break;
-
- case 'c':
- fprintf(stderr, "started reading\n");
-
- do {
- bt_lockpage (bt, page_no, BtLockRead, &page);
- cnt += page->act;
- next = bt_getid (page->right);
- bt_unlockpage (bt, page_no, BtLockRead);
- } while( page_no = next );
-
- cnt--; // remove stopper key
- fprintf(stderr, " Total keys read %d\n", cnt);
- break;
- }
-
- bt_close (bt);
-#ifdef unix
- return NULL;
-#else
- return 0;
-#endif
-}
-
-typedef struct timeval timer;
-
-int main (int argc, char **argv)
-{
-int idx, cnt, len, slot, err;
-int segsize, bits = 16;
-#ifdef unix
-pthread_t *threads;
-timer start, stop;
-#else
-time_t start[1], stop[1];
-HANDLE *threads;
-#endif
-double real_time;
-ThreadArg *args;
-uint poolsize = 0;
-int num = 0;
-char key[1];
-BtMgr *mgr;
-BtKey ptr;
-BtDb *bt;
-
- if( argc < 3 ) {
- fprintf (stderr, "Usage: %s idx_file Read/Write/Scan/Delete/Find [page_bits mapped_segments seg_bits line_numbers src_file1 src_file2 ... ]\n", argv[0]);
- fprintf (stderr, " where page_bits is the page size in bits\n");
- fprintf (stderr, " mapped_segments is the number of mmap segments in buffer pool\n");
- fprintf (stderr, " seg_bits is the size of individual segments in buffer pool in pages in bits\n");
- fprintf (stderr, " line_numbers = 1 to append line numbers to keys\n");
- fprintf (stderr, " src_file1 thru src_filen are files of keys separated by newline\n");
- exit(0);
- }
-
-#ifdef unix
- gettimeofday(&start, NULL);
-#else
- time(start);
-#endif
-
- if( argc > 3 )
- bits = atoi(argv[3]);
-
- if( argc > 4 )
- poolsize = atoi(argv[4]);
-
- if( !poolsize )
- fprintf (stderr, "Warning: no mapped_pool\n");
-
- if( poolsize > 65535 )
- fprintf (stderr, "Warning: mapped_pool > 65535 segments\n");
-
- if( argc > 5 )
- segsize = atoi(argv[5]);
- else
- segsize = 4; // 16 pages per mmap segment
-
- if( argc > 6 )
- num = atoi(argv[6]);
-
- cnt = argc - 7;
-#ifdef unix
- threads = malloc (cnt * sizeof(pthread_t));
-#else
- threads = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, cnt * sizeof(HANDLE));
-#endif
- args = malloc (cnt * sizeof(ThreadArg));
-
- mgr = bt_mgr ((argv[1]), BT_rw, bits, poolsize, segsize, poolsize / 8);
-
- if( !mgr ) {
- fprintf(stderr, "Index Open Error %s\n", argv[1]);
- exit (1);
- }
-
- // fire off threads
-
- for( idx = 0; idx < cnt; idx++ ) {
- args[idx].infile = argv[idx + 7];
- args[idx].type = argv[2][0];
- args[idx].mgr = mgr;
- args[idx].num = num;
- args[idx].idx = idx;
-#ifdef unix
- if( err = pthread_create (threads + idx, NULL, index_file, args + idx) )
- fprintf(stderr, "Error creating thread %d\n", err);
-#else
- threads[idx] = (HANDLE)_beginthreadex(NULL, 65536, index_file, args + idx, 0, NULL);
-#endif
- }
-
- // wait for termination
-
-#ifdef unix
- for( idx = 0; idx < cnt; idx++ )
- pthread_join (threads[idx], NULL);
- gettimeofday(&stop, NULL);
- real_time = 1000.0 * ( stop.tv_sec - start.tv_sec ) + 0.001 * (stop.tv_usec - start.tv_usec );
-#else
- WaitForMultipleObjects (cnt, threads, TRUE, INFINITE);
-
- for( idx = 0; idx < cnt; idx++ )
- CloseHandle(threads[idx]);
-
- time (stop);
- real_time = 1000 * (*stop - *start);
-#endif
- fprintf(stderr, " Time to complete: %.2f seconds\n", real_time/1000);
- bt_mgrclose (mgr);
-}
-
-#endif //STANDALONE
+++ /dev/null
-// foster btree version d
-// 26 DEC 2013
-
-// author: karl malbrain, malbrain@cal.berkeley.edu
-
-/*
-This work, including the source code, documentation
-and related data, is placed into the public domain.
-
-The orginal author is Karl Malbrain.
-
-THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
-OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
-MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
-ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
-RESULTING FROM THE USE, MODIFICATION, OR
-REDISTRIBUTION OF THIS SOFTWARE.
-*/
-
-// Please see the project home page for documentation
-// code.google.com/p/high-concurrency-btree
-
-#define _FILE_OFFSET_BITS 64
-#define _LARGEFILE64_SOURCE
-
-#ifdef linux
-#define _GNU_SOURCE
-#endif
-
-#ifdef unix
-#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <sys/time.h>
-#include <sys/mman.h>
-#include <errno.h>
-#include <pthread.h>
-#else
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <fcntl.h>
-#include <process.h>
-#include <intrin.h>
-#endif
-
-#include <memory.h>
-#include <string.h>
-
-typedef unsigned long long uid;
-
-#ifndef unix
-typedef unsigned long long off64_t;
-typedef unsigned short ushort;
-typedef unsigned int uint;
-#endif
-
-#define BT_ro 0x6f72 // ro
-#define BT_rw 0x7772 // rw
-
-#define BT_maxbits 24 // maximum page size in bits
-#define BT_minbits 9 // minimum page size in bits
-#define BT_minpage (1 << BT_minbits) // minimum page size
-#define BT_maxpage (1 << BT_maxbits) // maximum page size
-
-/*
-There are five lock types for each node in three independent sets:
-1. (set 1) AccessIntent: Sharable. Going to Read the node. Incompatible with NodeDelete.
-2. (set 1) NodeDelete: Exclusive. About to release the node. Incompatible with AccessIntent.
-3. (set 2) ReadLock: Sharable. Read the node. Incompatible with WriteLock.
-4. (set 2) WriteLock: Exclusive. Modify the node. Incompatible with ReadLock and other WriteLocks.
-5. (set 3) ParentLock: Exclusive. Have parent adopt/delete maximum foster child from the node.
-*/
-
-typedef enum{
- BtLockAccess,
- BtLockDelete,
- BtLockRead,
- BtLockWrite,
- BtLockParent
-}BtLock;
-
-// Define the length of the page and key pointers
-
-#define BtId 6
-
-// Page key slot definition.
-
-// If BT_maxbits is 15 or less, you can save 4 bytes
-// for each key stored by making the first two uints
-// into ushorts. You can also save 4 bytes by removing
-// the tod field from the key.
-
-// Keys are marked dead, but remain on the page until
-// it cleanup is called. The fence key (highest key) for
-// the page is always present, even after cleanup.
-
-typedef struct {
- uint off:BT_maxbits; // page offset for key start
- uint dead:1; // set for deleted key
- uint tod; // time-stamp for key
- unsigned char id[BtId]; // id associated with key
-} BtSlot;
-
-// The key structure occupies space at the upper end of
-// each page. It's a length byte followed by the value
-// bytes.
-
-typedef struct {
- unsigned char len;
- unsigned char key[1];
-} *BtKey;
-
-// The first part of an index page.
-// It is immediately followed
-// by the BtSlot array of keys.
-
-typedef struct Page {
- uint cnt; // count of keys in page
- uint act; // count of active keys
- uint min; // next key offset
- uint foster; // count of foster children
- unsigned char bits; // page size in bits
- unsigned char lvl:6; // level of page
- unsigned char kill:1; // page is being deleted
- unsigned char dirty:1; // page needs to be cleaned
- unsigned char right[BtId]; // page number to right
-} *BtPage;
-
-// latch table lock structure
-
-// exclusive is set for write access
-// share is count of read accessors
-// pending is count of waiting writers
-// grant write lock when share == 0
-
-typedef struct {
-#ifdef unix
- volatile uint exclusive:1;
- volatile uint pending:15;
- volatile uint share:16;
- pthread_mutex_t mut[1];
- pthread_cond_t cond[1];
-#else
- SRWLOCK srw[1];
-#endif
-} BtLatch;
-
-typedef struct {
- BtLatch readwr[1]; // read/write page lock
- BtLatch access[1]; // Access Intent/Page delete
- BtLatch parent[1]; // adoption of foster children
-} BtLatchSet;
-
-// The memory mapping pool table buffer manager entry
-
-typedef struct {
- unsigned long long int lru; // number of times accessed
- uid basepage; // mapped base page number
- char *map; // mapped memory pointer
- uint pin; // mapped page pin counter
- uint slot; // slot index in this array
- void *hashprev; // previous pool entry for the same hash idx
- void *hashnext; // next pool entry for the same hash idx
-#ifndef unix
- HANDLE hmap;
-#endif
-// array of page latch sets, one for each page in map segment
- BtLatchSet pagelatch[0];
-} BtPool;
-
-// The object structure for Btree access
-
-typedef struct {
- uint page_size; // page size
- uint page_bits; // page size in bits
- uint seg_bits; // seg size in pages in bits
- uint mode; // read-write mode
-#ifdef unix
- int idx;
- char *pooladvise; // bit maps for pool page advisements
-#else
- HANDLE idx;
-#endif
- uint poolcnt; // highest page pool node in use
- uint poolmax; // highest page pool node allocated
- uint poolmask; // total size of pages in mmap segment - 1
- uint hashsize; // size of Hash Table for pool entries
- volatile uint evicted; // last evicted hash table slot
- ushort *hash; // hash table of pool entries
- BtLatch *latch; // latches for hash table slots
- char *nodes; // memory pool page segments
-} BtMgr;
-
-typedef struct {
- BtMgr *mgr; // buffer manager for thread
- BtPage temp; // temporary frame buffer (memory mapped/file IO)
- BtPage alloc; // frame buffer for alloc page ( page 0 )
- BtPage cursor; // cached frame for start/next (never mapped)
- BtPage frame; // spare frame for the page split (never mapped)
- BtPage zero; // page frame for zeroes at end of file
- BtPage page; // current page
- uid page_no; // current page number
- uid cursor_page; // current cursor page number
- unsigned char *mem; // frame, cursor, page memory buffer
- int err; // last error
-} BtDb;
-
-typedef enum {
- BTERR_ok = 0,
- BTERR_struct,
- BTERR_ovflw,
- BTERR_lock,
- BTERR_map,
- BTERR_wrt,
- BTERR_hash
-} BTERR;
-
-// B-Tree functions
-extern void bt_close (BtDb *bt);
-extern BtDb *bt_open (BtMgr *mgr);
-extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod);
-extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
-extern uid bt_findkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_nextkey (BtDb *bt, uint slot);
-
-// manager functions
-extern BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolsize, uint segsize, uint hashsize);
-void bt_mgrclose (BtMgr *mgr);
-
-// Helper functions to return cursor slot values
-
-extern BtKey bt_key (BtDb *bt, uint slot);
-extern uid bt_uid (BtDb *bt, uint slot);
-extern uint bt_tod (BtDb *bt, uint slot);
-
-// BTree page number constants
-#define ALLOC_page 0
-#define ROOT_page 1
-#define LEAF_page 2
-
-// Number of levels to create in a new BTree
-
-#define MIN_lvl 2
-
-// The page is allocated from low and hi ends.
-// The key offsets and row-id's are allocated
-// from the bottom, while the text of the key
-// is allocated from the top. When the two
-// areas meet, the page is split into two.
-
-// A key consists of a length byte, two bytes of
-// index number (0 - 65534), and up to 253 bytes
-// of key value. Duplicate keys are discarded.
-// Associated with each key is a 48 bit row-id.
-
-// The b-tree root is always located at page 1.
-// The first leaf page of level zero is always
-// located on page 2.
-
-// When to root page fills, it is split in two and
-// the tree height is raised by a new root at page
-// one with two keys.
-
-// Deleted keys are marked with a dead bit until
-// page cleanup The fence key for a node is always
-// present, even after deletion and cleanup.
-
-// Groups of pages called segments from the btree are
-// cached with memory mapping. A hash table is used to keep
-// track of the cached segments. This behaviour is controlled
-// by the cache block size parameter to bt_open.
-
-// To achieve maximum concurrency one page is locked at a time
-// as the tree is traversed to find leaf key in question.
-
-// An adoption traversal leaves the parent node locked as the
-// tree is traversed to the level in quesiton.
-
-// Page 0 is dedicated to lock for new page extensions,
-// and chains empty pages together for reuse.
-
-// Empty pages are chained together through the ALLOC page and reused.
-
-// Access macros to address slot and key values from the page
-
-#define slotptr(page, slot) (((BtSlot *)(page+1)) + (slot-1))
-#define keyptr(page, slot) ((BtKey)((unsigned char*)(page) + slotptr(page, slot)->off))
-
-void bt_putid(unsigned char *dest, uid id)
-{
-int i = BtId;
-
- while( i-- )
- dest[i] = (unsigned char)id, id >>= 8;
-}
-
-uid bt_getid(unsigned char *src)
-{
-uid id = 0;
-int i;
-
- for( i = 0; i < BtId; i++ )
- id <<= 8, id |= *src++;
-
- return id;
-}
-
-void bt_mgrclose (BtMgr *mgr)
-{
-BtPool *pool;
-uint slot;
-
- // release mapped pages
- // note that slot zero is never used
-
- for( slot = 1; slot < mgr->poolmax; slot++ ) {
- pool = (BtPool *)(mgr->nodes + slot * (sizeof(BtPool) + (mgr->poolmask + 1) * sizeof(BtLatchSet)));
- if( pool->slot )
-#ifdef unix
- munmap (pool->map, (mgr->poolmask+1) << mgr->page_bits);
-#else
- {
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
- }
-#endif
- }
-
-#ifdef unix
- close (mgr->idx);
- free (mgr->nodes);
- free (mgr->hash);
- free (mgr->latch);
- free (mgr->pooladvise);
- free (mgr);
-#else
- FlushFileBuffers(mgr->idx);
- CloseHandle(mgr->idx);
- GlobalFree (mgr->nodes);
- GlobalFree (mgr->hash);
- GlobalFree (mgr->latch);
- GlobalFree (mgr);
-#endif
-}
-
-// close and release memory
-
-void bt_close (BtDb *bt)
-{
-#ifdef unix
- if ( bt->mem )
- free (bt->mem);
-#else
- if ( bt->mem)
- VirtualFree (bt->mem, 0, MEM_RELEASE);
-#endif
- free (bt);
-}
-
-// open/create new btree buffer manager
-
-// call with file_name, BT_openmode, bits in page size (e.g. 16),
-// size of mapped page pool (e.g. 8192)
-
-BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolmax, uint segsize, uint hashsize)
-{
-uint lvl, attr, cacheblk, last, slot, idx;
-BtPage alloc;
-int lockmode;
-off64_t size;
-uint amt[1];
-BtMgr* mgr;
-BtKey key;
-
-#ifndef unix
-SYSTEM_INFO sysinfo[1];
-#endif
-
- // determine sanity of page size and buffer pool
-
- if( bits > BT_maxbits )
- bits = BT_maxbits;
- else if( bits < BT_minbits )
- bits = BT_minbits;
-
- if( !poolmax )
- return NULL; // must have buffer pool
-
-#ifdef unix
- mgr = calloc (1, sizeof(BtMgr));
-
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
- lockmode = 1;
- break;
-
- case BT_ro:
- default:
- mgr->idx = open ((char*)name, O_RDONLY);
- lockmode = 0;
- break;
- }
- if( mgr->idx == -1 )
- return free(mgr), NULL;
-
- cacheblk = 4096; // minimum mmap segment size for unix
-
-#else
- mgr = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtMgr));
- attr = FILE_ATTRIBUTE_NORMAL;
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
- lockmode = 1;
- break;
-
- case BT_ro:
- default:
- mgr->idx = CreateFile(name, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, attr, NULL);
- lockmode = 0;
- break;
- }
- if( mgr->idx == INVALID_HANDLE_VALUE )
- return GlobalFree(mgr), NULL;
-
- // normalize cacheblk to multiple of sysinfo->dwAllocationGranularity
- GetSystemInfo(sysinfo);
- cacheblk = sysinfo->dwAllocationGranularity;
-#endif
-
-#ifdef unix
- alloc = malloc (BT_maxpage);
- *amt = 0;
-
- // read minimum page size to get root info
-
- if( size = lseek (mgr->idx, 0L, 2) ) {
- if( pread(mgr->idx, alloc, BT_minpage, 0) == BT_minpage )
- bits = alloc->bits;
- else
- return free(mgr), free(alloc), NULL;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#else
- alloc = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
- size = GetFileSize(mgr->idx, amt);
-
- if( size || *amt ) {
- if( !ReadFile(mgr->idx, (char *)alloc, BT_minpage, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- bits = alloc->bits;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- mgr->page_size = 1 << bits;
- mgr->page_bits = bits;
-
- mgr->poolmax = poolmax;
- mgr->mode = mode;
-
- if( cacheblk < mgr->page_size )
- cacheblk = mgr->page_size;
-
- // mask for partial memmaps
-
- mgr->poolmask = (cacheblk >> bits) - 1;
-
- // see if requested size of pages per memmap is greater
-
- if( (1 << segsize) > mgr->poolmask )
- mgr->poolmask = (1 << segsize) - 1;
-
- mgr->seg_bits = 0;
-
- while( (1 << mgr->seg_bits) <= mgr->poolmask )
- mgr->seg_bits++;
-
- mgr->hashsize = hashsize;
-
-#ifdef unix
- mgr->nodes = calloc (poolmax, (sizeof(BtPool) + (mgr->poolmask + 1) * sizeof(BtLatchSet)));
- mgr->hash = calloc (hashsize, sizeof(ushort));
- mgr->latch = calloc (hashsize, sizeof(BtLatch));
- mgr->pooladvise = calloc (poolmax, (mgr->poolmask + 1) / 8);
-#else
- mgr->nodes = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, poolmax * (sizeof(BtPool) + (mgr->poolmask + 1) * sizeof(BtLatchSet)));
- mgr->hash = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(ushort));
- mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtLatch));
-#endif
-
- // initialize buffer pool page latches
-
- for( slot = 1; slot < poolmax; slot++ ) {
- BtLatchSet *latchset = (BtLatchSet *)(mgr->nodes + slot * (sizeof(BtPool) + (mgr->poolmask + 1) * sizeof(BtLatchSet)));
- for( idx = 0; idx < mgr->poolmask + 1; idx++ ) {
-#ifdef unix
- pthread_mutex_init (latchset[idx].readwr->mut, NULL);
- pthread_cond_init (latchset[idx].readwr->cond, NULL);
- pthread_mutex_init (latchset[idx].access->mut, NULL);
- pthread_cond_init (latchset[idx].access->cond, NULL);
- pthread_mutex_init (latchset[idx].parent->mut, NULL);
- pthread_cond_init (latchset[idx].parent->cond, NULL);
-#else
- InitializeSRWLock (latchset[idx].readwr->srw);
- InitializeSRWLock (latchset[idx].access->srw);
- InitializeSRWLock (latchset[idx].parent->srw);
-#endif
- }
- }
-
- // initialize buffer pool mgr latches
-
- for( slot = 0; slot < hashsize; slot++ ) {
-#ifdef unix
- pthread_mutex_init (mgr->latch[slot].mut, NULL);
- pthread_cond_init (mgr->latch[slot].cond, NULL);
-#else
- InitializeSRWLock (mgr->latch[slot].srw);
-#endif
- }
-
- if( size || *amt )
- goto mgrxit;
-
- // initializes an empty b-tree with root page and page of leaves
-
- memset (alloc, 0, 1 << bits);
- bt_putid(alloc->right, MIN_lvl+1);
- alloc->bits = mgr->page_bits;
-
-#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- memset (alloc, 0, 1 << bits);
- alloc->bits = mgr->page_bits;
-
- for( lvl=MIN_lvl; lvl--; ) {
- slotptr(alloc, 1)->off = mgr->page_size - 3;
- bt_putid(slotptr(alloc, 1)->id, lvl ? MIN_lvl - lvl + 1 : 0); // next(lower) page number
- key = keyptr(alloc, 1);
- key->len = 2; // create stopper key
- key->key[0] = 0xff;
- key->key[1] = 0xff;
- alloc->min = mgr->page_size - 3;
- alloc->lvl = lvl;
- alloc->cnt = 1;
- alloc->act = 1;
-#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
- // create empty page area by writing last page of first
- // segment area (other pages are zeroed by O/S)
-
- if( mgr->poolmask ) {
- memset(alloc, 0, mgr->page_size);
- last = mgr->poolmask;
-
- while( last < MIN_lvl + 1 )
- last += mgr->poolmask + 1;
-
-#ifdef unix
- pwrite(mgr->idx, alloc, mgr->page_size, last << mgr->page_bits);
-#else
- SetFilePointer (mgr->idx, last << mgr->page_bits, NULL, FILE_BEGIN);
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
-mgrxit:
-#ifdef unix
- free (alloc);
-#else
- VirtualFree (alloc, 0, MEM_RELEASE);
-#endif
- return mgr;
-}
-
-// open BTree access method
-// based on buffer manager
-
-BtDb *bt_open (BtMgr *mgr)
-{
-BtDb *bt = malloc (sizeof(*bt));
-
- memset (bt, 0, sizeof(*bt));
- bt->mgr = mgr;
-#ifdef unix
- bt->mem = malloc (3 *mgr->page_size);
-#else
- bt->mem = VirtualAlloc(NULL, 3 * mgr->page_size, MEM_COMMIT, PAGE_READWRITE);
-#endif
- bt->frame = (BtPage)bt->mem;
- bt->zero = (BtPage)(bt->mem + 1 * mgr->page_size);
- bt->cursor = (BtPage)(bt->mem + 2 * mgr->page_size);
- return bt;
-}
-
-// compare two keys, returning > 0, = 0, or < 0
-// as the comparison value
-
-int keycmp (BtKey key1, unsigned char *key2, uint len2)
-{
-uint len1 = key1->len;
-int ans;
-
- if( ans = memcmp (key1->key, key2, len1 > len2 ? len2 : len1) )
- return ans;
-
- if( len1 > len2 )
- return 1;
- if( len1 < len2 )
- return -1;
-
- return 0;
-}
-
-// Latch Manager
-
-// wait if exclusive request is pending, or granted
-// and add 1 to the share count
-
-void bt_readlock(BtLatch *latch)
-{
-#ifdef unix
- pthread_mutex_lock (latch->mut);
-
- while( latch->pending || latch->exclusive )
- pthread_cond_wait (latch->cond, latch->mut);
-
- // add one to readers counter
-
- latch->share++;
- pthread_mutex_unlock (latch->mut);
-#else
- AcquireSRWLockShared (latch->srw);
-#endif
-}
-
-// wait for other read and write latches to relinquish
-
-void bt_writelock(BtLatch *latch)
-{
-#ifdef unix
- pthread_mutex_lock (latch->mut);
- latch->pending++;
-
- while( latch->share || latch->exclusive )
- pthread_cond_wait (latch->cond, latch->mut);
-
- latch->exclusive = 1;
- latch->pending--;
- pthread_mutex_unlock (latch->mut);
-#else
- AcquireSRWLockExclusive (latch->srw);
-#endif
-}
-
-// try to obtain write lock
-
-// return 1 if obtained,
-// 0 if already write or read locked
-
-int bt_writetry(BtLatch *latch)
-{
-int result = 0;
-
-#ifdef unix
- pthread_mutex_lock (latch->mut);
-
- if( !latch->share && !latch->exclusive )
- result = latch->exclusive = 1;
-
- pthread_mutex_unlock (latch->mut);
-#else
- result = TryAcquireSRWLockExclusive (latch->srw);
-#endif
- return result;
-}
-
-// clear write mode
-
-void bt_releasewrite(BtLatch *latch)
-{
-#ifdef unix
- pthread_mutex_lock (latch->mut);
- latch->exclusive = 0;
- pthread_cond_broadcast (latch->cond);
- pthread_mutex_unlock (latch->mut);
-#else
- ReleaseSRWLockExclusive (latch->srw);
-#endif
-}
-
-// decrement reader count
-
-void bt_releaseread(BtLatch *latch)
-{
-#ifdef unix
- pthread_mutex_lock (latch->mut);
-
- if( !--latch->share && latch->pending )
- pthread_cond_broadcast (latch->cond);
-
- pthread_mutex_unlock (latch->mut);
-#else
- ReleaseSRWLockShared (latch->srw);
-#endif
-}
-
-// Buffer Pool mgr
-
-// find segment in pool
-// must be called with hashslot idx locked
-// return NULL if not there
-// otherwise return node
-
-BtPool *bt_findpool(BtDb *bt, uid page_no, uint idx)
-{
-BtPool *pool;
-uint slot;
-
- // compute start of hash chain in pool
-
- if( slot = bt->mgr->hash[idx] )
- pool = (BtPool *)(bt->mgr->nodes + slot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
- else
- return NULL;
-
- page_no &= ~bt->mgr->poolmask;
-
- while( pool->basepage != page_no )
- if( pool = pool->hashnext )
- continue;
- else
- return NULL;
-
- return pool;
-}
-
-// add segment to hash table
-
-void bt_linkhash(BtDb *bt, BtPool *pool, uid page_no, int idx)
-{
-BtPool *node;
-uint slot;
-
- pool->hashprev = pool->hashnext = NULL;
- pool->basepage = page_no & ~bt->mgr->poolmask;
- pool->lru = 1;
-
- if( slot = bt->mgr->hash[idx] ) {
- node = (BtPool *)(bt->mgr->nodes + slot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
- pool->hashnext = node;
- node->hashprev = pool;
- }
-
- bt->mgr->hash[idx] = pool->slot;
-}
-
-// find best segment to evict from buffer pool
-
-BtPool *bt_findlru (BtDb *bt, uint hashslot)
-{
-unsigned long long int target = ~0LL;
-BtPool *pool = NULL, *node;
-
- if( !hashslot )
- return NULL;
-
- node = (BtPool *)(bt->mgr->nodes + hashslot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
-
- // scan pool entries under hash table slot
-
- do {
- if( node->pin )
- continue;
- if( node->lru > target )
- continue;
- target = node->lru;
- pool = node;
- } while( node = node->hashnext );
-
- return pool;
-}
-
-// map new buffer pool segment to virtual memory
-
-BTERR bt_mapsegment(BtDb *bt, BtPool *pool, uid page_no)
-{
-off64_t off = (page_no & ~bt->mgr->poolmask) << bt->mgr->page_bits;
-off64_t limit = off + ((bt->mgr->poolmask+1) << bt->mgr->page_bits);
-int flag;
-
-#ifdef unix
- flag = PROT_READ | ( bt->mgr->mode == BT_ro ? 0 : PROT_WRITE );
- pool->map = mmap (0, (bt->mgr->poolmask+1) << bt->mgr->page_bits, flag, MAP_SHARED, bt->mgr->idx, off);
- if( pool->map == MAP_FAILED )
- return bt->err = BTERR_map;
- // clear out madvise issued bits
- memset (bt->mgr->pooladvise + pool->slot * (bt->mgr->poolmask + 1) / 8, 0, (bt->mgr->poolmask + 1)/8);
-#else
- flag = ( bt->mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
- pool->hmap = CreateFileMapping(bt->mgr->idx, NULL, flag, (DWORD)(limit >> 32), (DWORD)limit, NULL);
- if( !pool->hmap )
- return bt->err = BTERR_map;
-
- flag = ( bt->mgr->mode == BT_ro ? FILE_MAP_READ : FILE_MAP_WRITE );
- pool->map = MapViewOfFile(pool->hmap, flag, (DWORD)(off >> 32), (DWORD)off, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
- if( !pool->map )
- return bt->err = BTERR_map;
-#endif
- return bt->err = 0;
-}
-
-// find or place requested page in segment-pool
-// return pool table entry, incrementing pin
-
-BtPool *bt_pinpage(BtDb *bt, uid page_no)
-{
-BtPool *pool, *node, *next;
-uint slot, idx, victim;
-BtLatchSet *set;
-
- // lock hash table chain
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx]);
-
- // look up in hash table
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releaseread (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // upgrade to write lock
-
- bt_releaseread (&bt->mgr->latch[idx]);
- bt_writelock (&bt->mgr->latch[idx]);
-
- // try to find page in pool with write lock
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // allocate a new pool node
- // and add to hash table
-
-#ifdef unix
- slot = __sync_fetch_and_add(&bt->mgr->poolcnt, 1);
-#else
- slot = _InterlockedIncrement (&bt->mgr->poolcnt) - 1;
-#endif
-
- if( ++slot < bt->mgr->poolmax ) {
- pool = (BtPool *)(bt->mgr->nodes + slot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
- pool->slot = slot;
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-
- // pool table is full
- // find best pool entry to evict
-
-#ifdef unix
- __sync_fetch_and_add(&bt->mgr->poolcnt, -1);
-#else
- _InterlockedDecrement (&bt->mgr->poolcnt);
-#endif
-
- while( 1 ) {
-#ifdef unix
- victim = __sync_fetch_and_add(&bt->mgr->evicted, 1);
-#else
- victim = _InterlockedIncrement (&bt->mgr->evicted) - 1;
-#endif
- victim %= bt->mgr->hashsize;
-
- // try to get write lock
- // skip entry if not obtained
-
- if( !bt_writetry (&bt->mgr->latch[victim]) )
- continue;
-
- // if cache entry is empty
- // or no slots are unpinned
- // skip this entry
-
- if( !(pool = bt_findlru(bt, bt->mgr->hash[victim])) ) {
- bt_releasewrite (&bt->mgr->latch[victim]);
- continue;
- }
-
- // unlink victim pool node from hash table
-
- if( node = pool->hashprev )
- node->hashnext = pool->hashnext;
- else if( node = pool->hashnext )
- bt->mgr->hash[victim] = node->slot;
- else
- bt->mgr->hash[victim] = 0;
-
- if( node = pool->hashnext )
- node->hashprev = pool->hashprev;
-
- bt_releasewrite (&bt->mgr->latch[victim]);
-
- // remove old file mapping
-#ifdef unix
- munmap (pool->map, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
-#else
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
-#endif
- pool->map = NULL;
-
- // create new pool mapping
- // and link into hash table
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-}
-
-// place write, read, or parent lock on requested page_no.
-// pin to buffer pool and return page pointer
-
-BTERR bt_lockpage(BtDb *bt, uid page_no, BtLock mode, BtPage *pageptr)
-{
-BtLatchSet *set;
-BtPool *pool;
-uint subpage;
-BtPage page;
-
- // find/create maping in pool table
- // and pin our pool slot
-
- if( pool = bt_pinpage(bt, page_no) )
- subpage = (uint)(page_no & bt->mgr->poolmask); // page within mapping
- else
- return bt->err;
-
- set = pool->pagelatch + subpage;
- page = (BtPage)(pool->map + (subpage << bt->mgr->page_bits));
-#ifdef unix
- {
- uint idx = subpage / 8;
- uint bit = subpage % 8;
-
- if( !((bt->mgr->pooladvise + pool->slot * (bt->mgr->poolmask + 1)/8)[idx] >> bit) & 1 ) {
- madvise (page, bt->mgr->page_size, MADV_WILLNEED);
- (bt->mgr->pooladvise + pool->slot * (bt->mgr->poolmask + 1)/8)[idx] |= 1 << bit;
- }
- }
-#endif
-
- switch( mode ) {
- case BtLockRead:
- bt_readlock (set->readwr);
- break;
- case BtLockWrite:
- bt_writelock (set->readwr);
- break;
- case BtLockAccess:
- bt_readlock (set->access);
- break;
- case BtLockDelete:
- bt_writelock (set->access);
- break;
- case BtLockParent:
- bt_writelock (set->parent);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
- if( pageptr )
- *pageptr = page;
-
- return bt->err = 0;
-}
-
-// remove write, read, or parent lock on requested page_no.
-
-BTERR bt_unlockpage(BtDb *bt, uid page_no, BtLock mode)
-{
-uint subpage, idx;
-BtLatchSet *set;
-BtPool *pool;
-
- // since page is pinned
- // it should still be in the buffer pool
- // and is in no danger of being a victim for reuse
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx]);
-
- if( pool = bt_findpool(bt, page_no, idx) )
- subpage = (uint)(page_no & bt->mgr->poolmask);
- else
- return bt->err = BTERR_hash;
-
- bt_releaseread (&bt->mgr->latch[idx]);
- set = pool->pagelatch + subpage;
-
- switch( mode ) {
- case BtLockRead:
- bt_releaseread (set->readwr);
- break;
- case BtLockWrite:
- bt_releasewrite (set->readwr);
- break;
- case BtLockAccess:
- bt_releaseread (set->access);
- break;
- case BtLockDelete:
- bt_releasewrite (set->access);
- break;
- case BtLockParent:
- bt_releasewrite (set->parent);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, -1);
-#else
- _InterlockedDecrement (&pool->pin);
-#endif
- return bt->err = 0;
-}
-
-// deallocate a deleted page
-// place on free chain out of allocator page
-
-BTERR bt_freepage(BtDb *bt, uid page_no)
-{
- // obtain delete lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- // obtain write lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // lock allocation page
-
- if ( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return bt->err;
-
- // store chain in second right
- bt_putid(bt->temp->right, bt_getid(bt->alloc[1].right));
- bt_putid(bt->alloc[1].right, page_no);
-
- // unlock page zero
-
- if( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return bt->err;
-
- // remove write lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // remove delete lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockDelete) )
- return bt->err;
-
- return 0;
-}
-
-// allocate a new page and write page into it
-
-uid bt_newpage(BtDb *bt, BtPage page)
-{
-uid new_page;
-BtPage pmap;
-int reuse;
-
- // lock page zero
-
- if ( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return 0;
-
- // use empty chain first
- // else allocate empty page
-
- if( new_page = bt_getid(bt->alloc[1].right) ) {
- if( bt_lockpage (bt, new_page, BtLockWrite, &bt->temp) )
- return 0;
- bt_putid(bt->alloc[1].right, bt_getid(bt->temp->right));
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
- reuse = 1;
- } else {
- new_page = bt_getid(bt->alloc->right);
- bt_putid(bt->alloc->right, new_page+1);
- reuse = 0;
- }
-#ifdef unix
- if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
-
- // if writing first page of pool block, zero last page in the block
-
- if ( !reuse && bt->mgr->poolmask > 0 && (new_page & bt->mgr->poolmask) == 0 )
- {
- // use zero buffer to write zeros
- memset(bt->zero, 0, bt->mgr->page_size);
- if ( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->poolmask) << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
- }
-#else
- // bring new page into pool and copy page.
- // this will extend the file into the new pages.
-
- if( bt_lockpage(bt, new_page, BtLockWrite, &pmap) )
- return 0;
-
- memcpy(pmap, page, bt->mgr->page_size);
-
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
-#endif
- // unlock page zero
-
- if ( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return 0;
-
- return new_page;
-}
-
-// find slot in page for given key at a given level
-
-int bt_findslot (BtDb *bt, unsigned char *key, uint len)
-{
-uint diff, higher = bt->page->cnt, low = 1, slot;
-
- // low is the lowest candidate, higher is already
- // tested as .ge. the given key, loop ends when they meet
-
- while( diff = higher - low ) {
- slot = low + ( diff >> 1 );
- if( keycmp (keyptr(bt->page, slot), key, len) < 0 )
- low = slot + 1;
- else
- higher = slot;
- }
-
- return higher;
-}
-
-// find and load page at given level for given key
-// leave page rd or wr locked as requested
-
-int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, uint lock)
-{
-uid page_no = ROOT_page, prevpage = 0;
-uint drill = 0xff, slot;
-uint mode, prevmode;
-
- // start at root of btree and drill down
-
- do {
- // determine lock mode of drill level
- mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead;
-
- bt->page_no = page_no;
-
- // obtain access lock using lock chaining with Access mode
-
- if( page_no > ROOT_page )
- if( bt_lockpage(bt, page_no, BtLockAccess, NULL) )
- return 0;
-
- if( prevpage )
- if( bt_unlockpage(bt, prevpage, prevmode) )
- return 0;
-
- // obtain read lock using lock chaining
- // and pin page contents
-
- if( bt_lockpage(bt, page_no, mode, &bt->page) )
- return 0;
-
- if( page_no > ROOT_page )
- if( bt_unlockpage(bt, page_no, BtLockAccess) )
- return 0;
-
- // re-read and re-lock root after determining actual level of root
-
- if( bt->page_no == ROOT_page )
- if( bt->page->lvl != drill) {
- drill = bt->page->lvl;
-
- if( lock == BtLockWrite && drill == lvl )
- if( bt_unlockpage(bt, page_no, mode) )
- return 0;
- else
- continue;
- }
-
- // if page is being deleted,
- // move back to preceeding page
-
- if( bt->page->kill ) {
- page_no = bt_getid (bt->page->right);
- continue;
- }
-
- // find key on page at this level
- // and descend to requested level
-
- slot = bt_findslot (bt, key, len);
-
- // is this slot a foster child?
-
- if( slot <= bt->page->cnt - bt->page->foster )
- if( drill == lvl )
- return slot;
- else
- drill--;
-
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
- continue;
- else
- return bt->err = BTERR_struct, 0;
-
- // continue down / right using overlapping locks
- // to protect pages being killed or split.
-
- prevmode = mode;
- prevpage = bt->page_no;
- page_no = bt_getid(slotptr(bt->page, slot)->id);
- } while( page_no );
-
- // return error on end of chain
-
- bt->err = BTERR_struct;
- return 0; // return error
-}
-
-// find and delete key on page by marking delete flag bit
-// when page becomes empty, delete it from the btree
-
-BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl)
-{
-unsigned char leftkey[256], rightkey[256];
-uid page_no, right;
-uint slot, tod;
-BtKey ptr;
-
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // if key is found delete it, otherwise ignore request
-
- if( !keycmp (ptr, key, len) )
- if( slotptr(bt->page, slot)->dead == 0 ) {
- slotptr(bt->page,slot)->dead = 1;
- if( slot < bt->page->cnt )
- bt->page->dirty = 1;
- bt->page->act--;
- }
-
- // return if page is not empty, or it has no right sibling
-
- right = bt_getid(bt->page->right);
- page_no = bt->page_no;
-
- if( !right || bt->page->act )
- return bt_unlockpage(bt, page_no, BtLockWrite);
-
- // obtain Parent lock over write lock
-
- if( bt_lockpage(bt, page_no, BtLockParent, NULL) )
- return bt->err;
-
- // cache copy of key to delete
-
- ptr = keyptr(bt->page, bt->page->cnt);
- memcpy(leftkey, ptr, ptr->len + 1);
-
- // lock and map right page
-
- if ( bt_lockpage(bt, right, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // pull contents of next page into current empty page
- memcpy (bt->page, bt->temp, bt->mgr->page_size);
-
- // cache copy of key to update
- ptr = keyptr(bt->temp, bt->temp->cnt);
- memcpy(rightkey, ptr, ptr->len + 1);
-
- // Mark right page as deleted and point it to left page
- // until we can post updates at higher level.
-
- bt_putid(bt->temp->right, page_no);
- bt->temp->kill = 1;
- bt->temp->cnt = 0;
-
- if( bt_unlockpage(bt, right, BtLockWrite) )
- return bt->err;
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // delete old lower key to consolidated node
-
- if( bt_deletekey (bt, leftkey + 1, *leftkey, lvl + 1) )
- return bt->err;
-
- // redirect higher key directly to consolidated node
-
- if( slot = bt_loadpage (bt, rightkey+1, *rightkey, lvl+1, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // since key already exists, update id
-
- if( keycmp (ptr, rightkey+1, *rightkey) )
- return bt->err = BTERR_struct;
-
- slotptr(bt->page, slot)->dead = 0;
- bt_putid(slotptr(bt->page,slot)->id, page_no);
- bt_unlockpage(bt, bt->page_no, BtLockWrite);
-
- // obtain write lock and
- // add right block to free chain
-
- if( bt_freepage (bt, right) )
- return bt->err;
-
- // remove ParentModify lock
-
- if( bt_unlockpage(bt, page_no, BtLockParent) )
- return bt->err;
-
- return 0;
-}
-
-// find key in leaf level and return row-id
-
-uid bt_findkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-BtKey ptr;
-uid id;
-
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- ptr = keyptr(bt->page, slot);
- else
- return 0;
-
- // if key exists, return row-id
- // otherwise return 0
-
- if( ptr->len == len && !memcmp (ptr->key, key, len) )
- id = bt_getid(slotptr(bt->page,slot)->id);
- else
- id = 0;
-
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
-
- return id;
-}
-
-// check page for space available,
-// clean if necessary and return
-// 0 - page needs splitting
-// 1 - go ahead
-
-uint bt_cleanpage(BtDb *bt, uint amt)
-{
-uint nxt = bt->mgr->page_size;
-BtPage page = bt->page;
-uint cnt = 0, idx = 0;
-uint max = page->cnt;
-BtKey key;
-
- if( page->min >= (max+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- // skip cleanup if nothing to reclaim
-
- if( !page->dirty )
- return 0;
-
- memcpy (bt->frame, page, bt->mgr->page_size);
-
- // skip page info and set rest of page to zero
-
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- page->dirty = 0;
- page->act = 0;
-
- // try cleaning up page first
-
- while( cnt++ < max ) {
- // always leave fence key and foster children in list
- if( cnt < max - page->foster && slotptr(bt->frame,cnt)->dead )
- continue;
-
- // copy key
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
-
- // copy slot
- memcpy(slotptr(page, ++idx)->id, slotptr(bt->frame, cnt)->id, BtId);
- if( !(slotptr(page, idx)->dead = slotptr(bt->frame, cnt)->dead) )
- page->act++;
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // see if page has enough space now, or does it need splitting?
-
- if( page->min >= (idx+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- return 0;
-}
-
-// add key to page
-// return with page unlocked
-
-BTERR bt_addkeytopage (BtDb *bt, uint slot, unsigned char *key, uint len, uid id, uint tod)
-{
-BtPage page = bt->page;
-uint idx;
-
- // calculate next available slot and copy key into page
-
- page->min -= len + 1;
- ((unsigned char *)page)[page->min] = len;
- memcpy ((unsigned char *)page + page->min +1, key, len );
-
- for( idx = slot; idx < page->cnt; idx++ )
- if( slotptr(page, idx)->dead )
- break;
-
- // now insert key into array before slot
- // preserving the fence slot
-
- if( idx == page->cnt )
- idx++, page->cnt++;
-
- page->act++;
-
- while( idx > slot )
- *slotptr(page, idx) = *slotptr(page, idx -1), idx--;
-
- bt_putid(slotptr(page,slot)->id, id);
- slotptr(page, slot)->off = page->min;
- slotptr(page, slot)->tod = tod;
- slotptr(page, slot)->dead = 0;
-
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
-}
-
-// split the root and raise the height of the btree
-
-BTERR bt_splitroot(BtDb *bt, uid right)
-{
-uint nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-BtPage root = bt->page;
-uid new_page;
-BtKey key;
-
- // Obtain an empty page to use, and copy the left page
- // contents into it from the root. Strip foster child key.
- // (it's the stopper key)
-
- root->act--;
- root->cnt--;
- root->foster--;
-
- // Save left fence key.
-
- key = keyptr(root, root->cnt);
- memcpy (fencekey, key, key->len + 1);
-
- // copy the lower keys into a new left page
-
- if( !(new_page = bt_newpage(bt, root)) )
- return bt->err;
-
- // preserve the page info at the bottom
- // and set rest of the root to zero
-
- memset (root+1, 0, bt->mgr->page_size - sizeof(*root));
-
- // insert left fence key on empty newroot page
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 1)->id, new_page);
- slotptr(root, 1)->off = nxt;
-
- // insert stopper key on newroot page
- // and increase the root height
-
- nxt -= 3;
- fencekey[0] = 2;
- fencekey[1] = 0xff;
- fencekey[2] = 0xff;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 2)->id, right);
- slotptr(root, 2)->off = nxt;
-
- bt_putid(root->right, 0);
- root->min = nxt; // reset lowest used offset and key count
- root->cnt = 2;
- root->act = 2;
- root->lvl++;
-
- // release root (bt->page)
-
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
-}
-
-// split already locked full node
-// return unlocked.
-
-BTERR bt_splitpage (BtDb *bt)
-{
-uint slot, cnt, idx, max, nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-uid page_no = bt->page_no;
-BtPage page = bt->page;
-uint tod = time(NULL);
-uint lvl = page->lvl;
-uid new_page, right;
-BtKey key;
-
- // initialize frame buffer
-
- memset (bt->frame, 0, bt->mgr->page_size);
- max = page->cnt - page->foster;
- tod = (uint)time(NULL);
- cnt = max / 2;
- idx = 0;
-
- // split higher half of keys to bt->frame
- // leaving foster children in the left node.
-
- while( cnt++ < max ) {
- key = keyptr(page, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)bt->frame + nxt, key, key->len + 1);
- memcpy(slotptr(bt->frame,++idx)->id, slotptr(page,cnt)->id, BtId);
- slotptr(bt->frame, idx)->tod = slotptr(page, cnt)->tod;
- slotptr(bt->frame, idx)->off = nxt;
- bt->frame->act++;
- }
-
- // transfer right link node
-
- if( page_no > ROOT_page ) {
- right = bt_getid (page->right);
- bt_putid(bt->frame->right, right);
- }
-
- bt->frame->bits = bt->mgr->page_bits;
- bt->frame->min = nxt;
- bt->frame->cnt = idx;
- bt->frame->lvl = lvl;
-
- // get new free page and write frame to it.
-
- if( !(new_page = bt_newpage(bt, bt->frame)) )
- return bt->err;
-
- // remember fence key for new page to add
- // as foster child
-
- key = keyptr(bt->frame, idx);
- memcpy (fencekey, key, key->len + 1);
-
- // update lower keys and foster children to continue in old page
-
- memcpy (bt->frame, page, bt->mgr->page_size);
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- nxt = bt->mgr->page_size;
- page->act = 0;
- cnt = 0;
- idx = 0;
-
- // assemble page of smaller keys
- // to remain in the old page
-
- while( cnt++ < max / 2 ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- // insert new foster child at beginning of the current foster children
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)page + nxt, fencekey, *fencekey + 1);
- bt_putid (slotptr(page,++idx)->id, new_page);
- slotptr(page, idx)->tod = tod;
- slotptr(page, idx)->off = nxt;
- page->foster++;
- page->act++;
-
- // continue with old foster child keys if any
-
- cnt = bt->frame->cnt - bt->frame->foster;
-
- while( cnt++ < bt->frame->cnt ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // link new right page
-
- bt_putid (page->right, new_page);
-
- // if current page is the root page, split it
-
- if( page_no == ROOT_page )
- return bt_splitroot (bt, new_page);
-
- // release wr lock on page
-
- if( bt_unlockpage (bt, page_no, BtLockWrite) )
- return bt->err;
-
- // obtain ParentModification lock for current page
- // to fix fence key and highest foster child on page
-
- if( bt_lockpage (bt, page_no, BtLockParent, NULL) )
- return bt->err;
-
- // get our highest foster child key to find in parent node
-
- if( bt_lockpage (bt, page_no, BtLockRead, &page) )
- return bt->err;
-
- key = keyptr(page, page->cnt);
- memcpy (fencekey, key, key->len+1);
-
- if( bt_unlockpage (bt, page_no, BtLockRead) )
- return bt->err;
-
-try_again:
-
- do {
- slot = bt_loadpage (bt, fencekey + 1, *fencekey, lvl + 1, BtLockWrite);
-
- if( !slot )
- return bt->err;
-
- // check if parent page has enough space for any possible key
-
- if( bt_cleanpage (bt, 256) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- } while( 1 );
-
- // see if we are still a foster child from another node
-
- if( bt_getid (slotptr(bt->page, slot)->id) != page_no ) {
- bt_unlockpage (bt, bt->page_no, BtLockWrite);
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- goto try_again;
- }
-
- // wait until readers from parent get their locks
-
- if( bt_lockpage (bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- if( bt_lockpage (bt, page_no, BtLockWrite, &page) )
- return bt->err;
-
- // switch parent fence key to foster child
-
- if( slotptr(page, page->cnt)->dead )
- slotptr(bt->page, slot)->dead = 1;
- else
- bt_putid (slotptr(bt->page, slot)->id, bt_getid(slotptr(page, page->cnt)->id));
-
- // remove highest foster child from our page
- // add our new fence key to parent
-
- page->cnt--;
- page->act--;
- page->foster--;
- page->dirty = 1;
- key = keyptr(page, page->cnt);
-
- if( bt_addkeytopage (bt, slot, key->key, key->len, page_no, tod) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockDelete) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockWrite) )
- return bt->err;
-
- return bt_unlockpage (bt, page_no, BtLockParent);
-}
-
-// Insert new key into the btree at leaf level.
-
-BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod)
-{
-uint slot, idx;
-BtPage page;
-BtKey ptr;
-
- while( 1 ) {
- if( slot = bt_loadpage (bt, key, len, 0, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- {
- if ( !bt->err )
- bt->err = BTERR_ovflw;
- return bt->err;
- }
-
- // if key already exists, update id and return
-
- page = bt->page;
-
- if( !keycmp (ptr, key, len) ) {
- slotptr(page, slot)->dead = 0;
- slotptr(page, slot)->tod = tod;
- bt_putid(slotptr(page,slot)->id, id);
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
- }
-
- // check if page has enough space
-
- if( bt_cleanpage (bt, len) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- }
-
- return bt_addkeytopage (bt, slot, key, len, id, tod);
-}
-
-// cache page of keys into cursor and return starting slot for given key
-
-uint bt_startkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-
- // cache page for retrieval
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- memcpy (bt->cursor, bt->page, bt->mgr->page_size);
- bt->cursor_page = bt->page_no;
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
-
- return slot;
-}
-
-// return next slot for cursor page
-// or slide cursor right into next page
-
-uint bt_nextkey (BtDb *bt, uint slot)
-{
-BtPage page;
-uid right;
-
- do {
- right = bt_getid(bt->cursor->right);
- while( slot++ < bt->cursor->cnt - bt->cursor->foster )
- if( slotptr(bt->cursor,slot)->dead )
- continue;
- else if( right || (slot < bt->cursor->cnt - bt->cursor->foster) )
- return slot;
- else
- break;
-
- if( !right )
- break;
-
- bt->cursor_page = right;
-
- if( bt_lockpage(bt, right, BtLockRead, &page) )
- return 0;
-
- memcpy (bt->cursor, page, bt->mgr->page_size);
-
- if ( bt_unlockpage(bt, right, BtLockRead) )
- return 0;
-
- slot = 0;
- } while( 1 );
-
- return bt->err = 0;
-}
-
-BtKey bt_key(BtDb *bt, uint slot)
-{
- return keyptr(bt->cursor, slot);
-}
-
-uid bt_uid(BtDb *bt, uint slot)
-{
- return bt_getid(slotptr(bt->cursor,slot)->id);
-}
-
-uint bt_tod(BtDb *bt, uint slot)
-{
- return slotptr(bt->cursor,slot)->tod;
-}
-
-
-#ifdef STANDALONE
-
-typedef struct {
- char type, idx;
- char *infile;
- BtMgr *mgr;
- int num;
-} ThreadArg;
-
-// standalone program to index file of keys
-// then list them onto std-out
-
-#ifdef unix
-void *index_file (void *arg)
-#else
-uint __stdcall index_file (void *arg)
-#endif
-{
-int line = 0, found = 0, cnt = 0;
-uid next, page_no = LEAF_page; // start on first page of leaves
-unsigned char key[256];
-ThreadArg *args = arg;
-int ch, len = 0, slot;
-time_t tod[1];
-BtPage page;
-BtKey ptr;
-BtDb *bt;
-FILE *in;
-
- bt = bt_open (args->mgr);
- time (tod);
-
- switch(args->type | 0x20)
- {
- case 'w':
- fprintf(stderr, "started indexing for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
-
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_insertkey (bt, key, len, line, *tod) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys\n", args->infile, line);
- break;
-
- case 'd':
- fprintf(stderr, "started deleting keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_deletekey (bt, key, len, 0) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for keys, %d \n", args->infile, line);
- break;
-
- case 'f':
- fprintf(stderr, "started finding keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_findkey (bt, key, len) )
- found++;
- else if( bt->err )
- fprintf(stderr, "Error %d Syserr %d Line: %d\n", bt->err, errno, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys, found %d\n", args->infile, line, found);
- break;
-
- case 's':
- len = key[0] = 0;
-
- fprintf(stderr, "started reading\n");
-
- if( slot = bt_startkey (bt, key, len) )
- slot--;
- else
- fprintf(stderr, "Error %d in StartKey. Syserror: %d\n", bt->err, errno), exit(0);
-
- while( slot = bt_nextkey (bt, slot) ) {
- ptr = bt_key(bt, slot);
- fwrite (ptr->key, ptr->len, 1, stdout);
- fputc ('\n', stdout);
- }
-
- break;
-
- case 'c':
- fprintf(stderr, "started reading\n");
-
- do {
- bt_lockpage (bt, page_no, BtLockRead, &page);
- cnt += page->act;
- next = bt_getid (page->right);
- bt_unlockpage (bt, page_no, BtLockRead);
- } while( page_no = next );
-
- cnt--; // remove stopper key
- fprintf(stderr, " Total keys read %d\n", cnt);
- break;
- }
-
- bt_close (bt);
-#ifdef unix
- return NULL;
-#else
- return 0;
-#endif
-}
-
-typedef struct timeval timer;
-
-int main (int argc, char **argv)
-{
-int idx, cnt, len, slot, err;
-int segsize, bits = 16;
-#ifdef unix
-pthread_t *threads;
-timer start, stop;
-#else
-time_t start[1], stop[1];
-HANDLE *threads;
-#endif
-double real_time;
-ThreadArg *args;
-uint poolsize = 0;
-int num = 0;
-char key[1];
-BtMgr *mgr;
-BtKey ptr;
-BtDb *bt;
-
- if( argc < 3 ) {
- fprintf (stderr, "Usage: %s idx_file Read/Write/Scan/Delete/Find [page_bits mapped_segments seg_bits line_numbers src_file1 src_file2 ... ]\n", argv[0]);
- fprintf (stderr, " where page_bits is the page size in bits\n");
- fprintf (stderr, " mapped_segments is the number of mmap segments in buffer pool\n");
- fprintf (stderr, " seg_bits is the size of individual segments in buffer pool in pages in bits\n");
- fprintf (stderr, " line_numbers = 1 to append line numbers to keys\n");
- fprintf (stderr, " src_file1 thru src_filen are files of keys separated by newline\n");
- exit(0);
- }
-
-#ifdef unix
- gettimeofday(&start, NULL);
-#else
- time(start);
-#endif
-
- if( argc > 3 )
- bits = atoi(argv[3]);
-
- if( argc > 4 )
- poolsize = atoi(argv[4]);
-
- if( !poolsize )
- fprintf (stderr, "Warning: no mapped_pool\n");
-
- if( poolsize > 65535 )
- fprintf (stderr, "Warning: mapped_pool > 65535 segments\n");
-
- if( argc > 5 )
- segsize = atoi(argv[5]);
- else
- segsize = 4; // 16 pages per mmap segment
-
- if( argc > 6 )
- num = atoi(argv[6]);
-
- cnt = argc - 7;
-#ifdef unix
- threads = malloc (cnt * sizeof(pthread_t));
-#else
- threads = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, cnt * sizeof(HANDLE));
-#endif
- args = malloc (cnt * sizeof(ThreadArg));
-
- mgr = bt_mgr ((argv[1]), BT_rw, bits, poolsize, segsize, poolsize / 8);
-
- if( !mgr ) {
- fprintf(stderr, "Index Open Error %s\n", argv[1]);
- exit (1);
- }
-
- // fire off threads
-
- for( idx = 0; idx < cnt; idx++ ) {
- args[idx].infile = argv[idx + 7];
- args[idx].type = argv[2][0];
- args[idx].mgr = mgr;
- args[idx].num = num;
- args[idx].idx = idx;
-#ifdef unix
- if( err = pthread_create (threads + idx, NULL, index_file, args + idx) )
- fprintf(stderr, "Error creating thread %d\n", err);
-#else
- threads[idx] = (HANDLE)_beginthreadex(NULL, 65536, index_file, args + idx, 0, NULL);
-#endif
- }
-
- // wait for termination
-
-#ifdef unix
- for( idx = 0; idx < cnt; idx++ )
- pthread_join (threads[idx], NULL);
- gettimeofday(&stop, NULL);
- real_time = 1000.0 * ( stop.tv_sec - start.tv_sec ) + 0.001 * (stop.tv_usec - start.tv_usec );
-#else
- WaitForMultipleObjects (cnt, threads, TRUE, INFINITE);
-
- for( idx = 0; idx < cnt; idx++ )
- CloseHandle(threads[idx]);
-
- time (stop);
- real_time = 1000 * (*stop - *start);
-#endif
- fprintf(stderr, " Time to complete: %.2f seconds\n", real_time/1000);
- bt_mgrclose (mgr);
-}
-
-#endif //STANDALONE
+++ /dev/null
-// foster btree version d
-// 24 DEC 2013
-
-// author: karl malbrain, malbrain@cal.berkeley.edu
-
-/*
-This work, including the source code, documentation
-and related data, is placed into the public domain.
-
-The orginal author is Karl Malbrain.
-
-THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
-OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
-MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
-ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
-RESULTING FROM THE USE, MODIFICATION, OR
-REDISTRIBUTION OF THIS SOFTWARE.
-*/
-
-// Please see the project home page for documentation
-// code.google.com/p/high-concurrency-btree
-
-#define _FILE_OFFSET_BITS 64
-#define _LARGEFILE64_SOURCE
-
-#ifdef linux
-#define _GNU_SOURCE
-#endif
-
-#ifdef unix
-#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <sys/time.h>
-#include <sys/mman.h>
-#include <errno.h>
-#include <pthread.h>
-#else
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <fcntl.h>
-#include <process.h>
-#include <intrin.h>
-#endif
-
-#include <memory.h>
-#include <string.h>
-
-typedef unsigned long long uid;
-
-#ifndef unix
-typedef unsigned long long off64_t;
-typedef unsigned short ushort;
-typedef unsigned int uint;
-#endif
-
-#define BT_ro 0x6f72 // ro
-#define BT_rw 0x7772 // rw
-
-#define BT_maxbits 24 // maximum page size in bits
-#define BT_minbits 9 // minimum page size in bits
-#define BT_minpage (1 << BT_minbits) // minimum page size
-#define BT_maxpage (1 << BT_maxbits) // maximum page size
-
-/*
-There are five lock types for each node in three independent sets:
-1. (set 1) AccessIntent: Sharable. Going to Read the node. Incompatible with NodeDelete.
-2. (set 1) NodeDelete: Exclusive. About to release the node. Incompatible with AccessIntent.
-3. (set 2) ReadLock: Sharable. Read the node. Incompatible with WriteLock.
-4. (set 2) WriteLock: Exclusive. Modify the node. Incompatible with ReadLock and other WriteLocks.
-5. (set 3) ParentLock: Exclusive. Have parent adopt/delete maximum foster child from the node.
-*/
-
-typedef enum{
- BtLockAccess,
- BtLockDelete,
- BtLockRead,
- BtLockWrite,
- BtLockParent
-}BtLock;
-
-// Define the length of the page and key pointers
-
-#define BtId 6
-
-// Page key slot definition.
-
-// If BT_maxbits is 15 or less, you can save 4 bytes
-// for each key stored by making the first two uints
-// into ushorts. You can also save 4 bytes by removing
-// the tod field from the key.
-
-// Keys are marked dead, but remain on the page until
-// it cleanup is called. The fence key (highest key) for
-// the page is always present, even after cleanup.
-
-typedef struct {
- uint off:BT_maxbits; // page offset for key start
- uint dead:1; // set for deleted key
- uint tod; // time-stamp for key
- unsigned char id[BtId]; // id associated with key
-} BtSlot;
-
-// The key structure occupies space at the upper end of
-// each page. It's a length byte followed by the value
-// bytes.
-
-typedef struct {
- unsigned char len;
- unsigned char key[1];
-} *BtKey;
-
-// The first part of an index page.
-// It is immediately followed
-// by the BtSlot array of keys.
-
-typedef struct Page {
- uint cnt; // count of keys in page
- uint act; // count of active keys
- uint min; // next key offset
- uint foster; // count of foster children
- unsigned char bits; // page size in bits
- unsigned char lvl:6; // level of page
- unsigned char kill:1; // page is being deleted
- unsigned char dirty:1; // page needs to be cleaned
- unsigned char right[BtId]; // page number to right
-} *BtPage;
-
-// latch table lock structure
-
-typedef struct {
-#ifdef unix
- pthread_rwlock_t lock[1];
-#else
- SRWLOCK srw[1];
-#endif
-} BtLatch;
-
-typedef struct {
- BtLatch readwr[1]; // read/write page lock
- BtLatch access[1]; // Access Intent/Page delete
- BtLatch parent[1]; // adoption of foster children
-} BtLatchSet;
-
-// The memory mapping pool table buffer manager entry
-
-typedef struct {
- unsigned long long int lru; // number of times accessed
- uid basepage; // mapped base page number
- char *map; // mapped memory pointer
- uint pin; // mapped page pin counter
- uint slot; // slot index in this array
- void *hashprev; // previous pool entry for the same hash idx
- void *hashnext; // next pool entry for the same hash idx
-#ifndef unix
- HANDLE hmap;
-#endif
-// array of page latch sets, one for each page in map segment
- BtLatchSet pagelatch[0];
-} BtPool;
-
-// The object structure for Btree access
-
-typedef struct {
- uint page_size; // page size
- uint page_bits; // page size in bits
- uint seg_bits; // seg size in pages in bits
- uint mode; // read-write mode
-#ifdef unix
- int idx;
- char *pooladvise; // bit maps for pool page advisements
-#else
- HANDLE idx;
-#endif
- uint poolcnt; // highest page pool node in use
- uint poolmax; // highest page pool node allocated
- uint poolmask; // total size of pages in mmap segment - 1
- uint hashsize; // size of Hash Table for pool entries
- volatile uint evicted; // last evicted hash table slot
- ushort *hash; // hash table of pool entries
- BtLatch *latch; // latches for hash table slots
- char *nodes; // memory pool page segments
-} BtMgr;
-
-typedef struct {
- BtMgr *mgr; // buffer manager for thread
- BtPage temp; // temporary frame buffer (memory mapped/file IO)
- BtPage alloc; // frame buffer for alloc page ( page 0 )
- BtPage cursor; // cached frame for start/next (never mapped)
- BtPage frame; // spare frame for the page split (never mapped)
- BtPage zero; // page frame for zeroes at end of file
- BtPage page; // current page
- uid page_no; // current page number
- uid cursor_page; // current cursor page number
- unsigned char *mem; // frame, cursor, page memory buffer
- int err; // last error
-} BtDb;
-
-typedef enum {
- BTERR_ok = 0,
- BTERR_struct,
- BTERR_ovflw,
- BTERR_lock,
- BTERR_map,
- BTERR_wrt,
- BTERR_hash
-} BTERR;
-
-// B-Tree functions
-extern void bt_close (BtDb *bt);
-extern BtDb *bt_open (BtMgr *mgr);
-extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod);
-extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
-extern uid bt_findkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_nextkey (BtDb *bt, uint slot);
-
-// manager functions
-extern BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolsize, uint segsize, uint hashsize);
-void bt_mgrclose (BtMgr *mgr);
-
-// Helper functions to return cursor slot values
-
-extern BtKey bt_key (BtDb *bt, uint slot);
-extern uid bt_uid (BtDb *bt, uint slot);
-extern uint bt_tod (BtDb *bt, uint slot);
-
-// BTree page number constants
-#define ALLOC_page 0
-#define ROOT_page 1
-#define LEAF_page 2
-
-// Number of levels to create in a new BTree
-
-#define MIN_lvl 2
-
-// The page is allocated from low and hi ends.
-// The key offsets and row-id's are allocated
-// from the bottom, while the text of the key
-// is allocated from the top. When the two
-// areas meet, the page is split into two.
-
-// A key consists of a length byte, two bytes of
-// index number (0 - 65534), and up to 253 bytes
-// of key value. Duplicate keys are discarded.
-// Associated with each key is a 48 bit row-id.
-
-// The b-tree root is always located at page 1.
-// The first leaf page of level zero is always
-// located on page 2.
-
-// When to root page fills, it is split in two and
-// the tree height is raised by a new root at page
-// one with two keys.
-
-// Deleted keys are marked with a dead bit until
-// page cleanup The fence key for a node is always
-// present, even after deletion and cleanup.
-
-// Groups of pages called segments from the btree are
-// cached with memory mapping. A hash table is used to keep
-// track of the cached segments. This behaviour is controlled
-// by the cache block size parameter to bt_open.
-
-// To achieve maximum concurrency one page is locked at a time
-// as the tree is traversed to find leaf key in question.
-
-// An adoption traversal leaves the parent node locked as the
-// tree is traversed to the level in quesiton.
-
-// Page 0 is dedicated to lock for new page extensions,
-// and chains empty pages together for reuse.
-
-// Empty pages are chained together through the ALLOC page and reused.
-
-// Access macros to address slot and key values from the page
-
-#define slotptr(page, slot) (((BtSlot *)(page+1)) + (slot-1))
-#define keyptr(page, slot) ((BtKey)((unsigned char*)(page) + slotptr(page, slot)->off))
-
-void bt_putid(unsigned char *dest, uid id)
-{
-int i = BtId;
-
- while( i-- )
- dest[i] = (unsigned char)id, id >>= 8;
-}
-
-uid bt_getid(unsigned char *src)
-{
-uid id = 0;
-int i;
-
- for( i = 0; i < BtId; i++ )
- id <<= 8, id |= *src++;
-
- return id;
-}
-
-void bt_mgrclose (BtMgr *mgr)
-{
-BtPool *pool;
-uint slot;
-
- // release mapped pages
- // note that slot zero is never used
-
- for( slot = 1; slot < mgr->poolmax; slot++ ) {
- pool = (BtPool *)(mgr->nodes + slot * (sizeof(BtPool) + (mgr->poolmask + 1) * sizeof(BtLatchSet)));
- if( pool->slot )
-#ifdef unix
- munmap (pool->map, (mgr->poolmask+1) << mgr->page_bits);
-#else
- {
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
- }
-#endif
- }
-
-#ifdef unix
- close (mgr->idx);
- free (mgr->nodes);
- free (mgr->hash);
- free (mgr->latch);
- free (mgr->pooladvise);
- free (mgr);
-#else
- FlushFileBuffers(mgr->idx);
- CloseHandle(mgr->idx);
- GlobalFree (mgr->nodes);
- GlobalFree (mgr->hash);
- GlobalFree (mgr->latch);
- GlobalFree (mgr);
-#endif
-}
-
-// close and release memory
-
-void bt_close (BtDb *bt)
-{
-#ifdef unix
- if ( bt->mem )
- free (bt->mem);
-#else
- if ( bt->mem)
- VirtualFree (bt->mem, 0, MEM_RELEASE);
-#endif
- free (bt);
-}
-
-// open/create new btree buffer manager
-
-// call with file_name, BT_openmode, bits in page size (e.g. 16),
-// size of mapped page pool (e.g. 8192)
-
-BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolmax, uint segsize, uint hashsize)
-{
-uint lvl, attr, cacheblk, last, slot, idx;
-BtPage alloc;
-int lockmode;
-off64_t size;
-uint amt[1];
-BtMgr* mgr;
-BtKey key;
-
-#ifdef unix
-pthread_rwlockattr_t rwattr[1];
-#else
-SYSTEM_INFO sysinfo[1];
-#endif
-
- // determine sanity of page size and buffer pool
-
- if( bits > BT_maxbits )
- bits = BT_maxbits;
- else if( bits < BT_minbits )
- bits = BT_minbits;
-
- if( !poolmax )
- return NULL; // must have buffer pool
-
-#ifdef unix
- mgr = calloc (1, sizeof(BtMgr));
-
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
- lockmode = 1;
- break;
-
- case BT_ro:
- default:
- mgr->idx = open ((char*)name, O_RDONLY);
- lockmode = 0;
- break;
- }
- if( mgr->idx == -1 )
- return free(mgr), NULL;
-
- cacheblk = 4096; // minimum mmap segment size for unix
-
-#else
- mgr = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtMgr));
- attr = FILE_ATTRIBUTE_NORMAL;
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
- lockmode = 1;
- break;
-
- case BT_ro:
- default:
- mgr->idx = CreateFile(name, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, attr, NULL);
- lockmode = 0;
- break;
- }
- if( mgr->idx == INVALID_HANDLE_VALUE )
- return GlobalFree(mgr), NULL;
-
- // normalize cacheblk to multiple of sysinfo->dwAllocationGranularity
- GetSystemInfo(sysinfo);
- cacheblk = sysinfo->dwAllocationGranularity;
-#endif
-
-#ifdef unix
- alloc = malloc (BT_maxpage);
- *amt = 0;
-
- // read minimum page size to get root info
-
- if( size = lseek (mgr->idx, 0L, 2) ) {
- if( pread(mgr->idx, alloc, BT_minpage, 0) == BT_minpage )
- bits = alloc->bits;
- else
- return free(mgr), free(alloc), NULL;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#else
- alloc = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
- size = GetFileSize(mgr->idx, amt);
-
- if( size || *amt ) {
- if( !ReadFile(mgr->idx, (char *)alloc, BT_minpage, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- bits = alloc->bits;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- mgr->page_size = 1 << bits;
- mgr->page_bits = bits;
-
- mgr->poolmax = poolmax;
- mgr->mode = mode;
-
- if( cacheblk < mgr->page_size )
- cacheblk = mgr->page_size;
-
- // mask for partial memmaps
-
- mgr->poolmask = (cacheblk >> bits) - 1;
-
- // see if requested size of pages per memmap is greater
-
- if( (1 << segsize) > mgr->poolmask )
- mgr->poolmask = (1 << segsize) - 1;
-
- mgr->seg_bits = 0;
-
- while( (1 << mgr->seg_bits) <= mgr->poolmask )
- mgr->seg_bits++;
-
- mgr->hashsize = hashsize;
-
-#ifdef unix
- mgr->nodes = calloc (poolmax, (sizeof(BtPool) + (mgr->poolmask + 1) * sizeof(BtLatchSet)));
- mgr->hash = calloc (hashsize, sizeof(ushort));
- mgr->latch = calloc (hashsize, sizeof(BtLatch));
- mgr->pooladvise = calloc (poolmax, (mgr->poolmask + 8) / 8);
-#else
- mgr->nodes = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, poolmax * (sizeof(BtPool) + (mgr->poolmask + 1) * sizeof(BtLatchSet)));
- mgr->hash = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(ushort));
- mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtLatch));
-#endif
-
-#ifdef unix
- pthread_rwlockattr_init (rwattr);
- pthread_rwlockattr_setkind_np (rwattr, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
-#endif
-
- // initialize buffer pool mgr latches
-
- for( slot = 0; slot < hashsize; slot++ ) {
-#ifdef unix
- pthread_rwlock_init (mgr->latch[slot].lock, rwattr);
-#else
- InitializeSRWLock (mgr->latch[slot].srw);
-#endif
- }
-
- // initialize buffer pool page latches
-#ifdef unix
-// pthread_rwlockattr_setpshared (rwattr, PTHREAD_PROCESS_SHARED);
-#endif
- for( slot = 1; slot < poolmax; slot++ ) {
- BtLatchSet *latchset = (BtLatchSet *)(mgr->nodes + slot * (sizeof(BtPool) + (mgr->poolmask + 1) * sizeof(BtLatchSet)) + sizeof(BtPool));
- for( idx = 0; idx < mgr->poolmask + 1; idx++ ) {
-#ifdef unix
- pthread_rwlock_init (latchset[idx].readwr->lock, rwattr);
- pthread_rwlock_init (latchset[idx].access->lock, rwattr);
- pthread_rwlock_init (latchset[idx].parent->lock, rwattr);
-#else
- InitializeSRWLock (latchset[idx].readwr->srw);
- InitializeSRWLock (latchset[idx].access->srw);
- InitializeSRWLock (latchset[idx].parent->srw);
-#endif
- }
- }
-
- if( size || *amt )
- goto mgrxit;
-
- // initializes an empty b-tree with root page and page of leaves
-
- memset (alloc, 0, 1 << bits);
- bt_putid(alloc->right, MIN_lvl+1);
- alloc->bits = mgr->page_bits;
-
-#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- memset (alloc, 0, 1 << bits);
- alloc->bits = mgr->page_bits;
-
- for( lvl=MIN_lvl; lvl--; ) {
- slotptr(alloc, 1)->off = mgr->page_size - 3;
- bt_putid(slotptr(alloc, 1)->id, lvl ? MIN_lvl - lvl + 1 : 0); // next(lower) page number
- key = keyptr(alloc, 1);
- key->len = 2; // create stopper key
- key->key[0] = 0xff;
- key->key[1] = 0xff;
- alloc->min = mgr->page_size - 3;
- alloc->lvl = lvl;
- alloc->cnt = 1;
- alloc->act = 1;
-#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
- // create empty page area by writing last page of first
- // segment area (other pages are zeroed by O/S)
-
- if( mgr->poolmask ) {
- memset(alloc, 0, mgr->page_size);
- last = mgr->poolmask;
-
- while( last < MIN_lvl + 1 )
- last += mgr->poolmask + 1;
-
-#ifdef unix
- pwrite(mgr->idx, alloc, mgr->page_size, last << mgr->page_bits);
-#else
- SetFilePointer (mgr->idx, last << mgr->page_bits, NULL, FILE_BEGIN);
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
-mgrxit:
-#ifdef unix
- free (alloc);
-#else
- VirtualFree (alloc, 0, MEM_RELEASE);
-#endif
- return mgr;
-}
-
-// open BTree access method
-// based on buffer manager
-
-BtDb *bt_open (BtMgr *mgr)
-{
-BtDb *bt = malloc (sizeof(*bt));
-
- memset (bt, 0, sizeof(*bt));
- bt->mgr = mgr;
-#ifdef unix
- bt->mem = malloc (3 *mgr->page_size);
-#else
- bt->mem = VirtualAlloc(NULL, 3 * mgr->page_size, MEM_COMMIT, PAGE_READWRITE);
-#endif
- bt->frame = (BtPage)bt->mem;
- bt->zero = (BtPage)(bt->mem + 1 * mgr->page_size);
- bt->cursor = (BtPage)(bt->mem + 2 * mgr->page_size);
- return bt;
-}
-
-// compare two keys, returning > 0, = 0, or < 0
-// as the comparison value
-
-int keycmp (BtKey key1, unsigned char *key2, uint len2)
-{
-uint len1 = key1->len;
-int ans;
-
- if( ans = memcmp (key1->key, key2, len1 > len2 ? len2 : len1) )
- return ans;
-
- if( len1 > len2 )
- return 1;
- if( len1 < len2 )
- return -1;
-
- return 0;
-}
-
-// Latch Manager
-
-void bt_readlock(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_rdlock (latch->lock);
-#else
- AcquireSRWLockShared (latch->srw);
-#endif
-}
-
-// wait for other read and write latches to relinquish
-
-void bt_writelock(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_wrlock (latch->lock);
-#else
- AcquireSRWLockExclusive (latch->srw);
-#endif
-}
-
-// try to obtain write lock
-
-// return 1 if obtained,
-// 0 if already write or read locked
-
-int bt_writetry(BtLatch *latch)
-{
-int result = 0;
-
-#ifdef unix
- result = !pthread_rwlock_trywrlock (latch->lock);
-#else
- result = TryAcquireSRWLockExclusive (latch->srw);
-#endif
- return result;
-}
-
-// clear write mode
-
-void bt_releasewrite(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_unlock (latch->lock);
-#else
- ReleaseSRWLockExclusive (latch->srw);
-#endif
-}
-
-// decrement reader count
-
-void bt_releaseread(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_unlock (latch->lock);
-#else
- ReleaseSRWLockShared (latch->srw);
-#endif
-}
-
-// Buffer Pool mgr
-
-// find segment in pool
-// must be called with hashslot idx locked
-// return NULL if not there
-// otherwise return node
-
-BtPool *bt_findpool(BtDb *bt, uid page_no, uint idx)
-{
-BtPool *pool;
-uint slot;
-
- // compute start of hash chain in pool
-
- if( slot = bt->mgr->hash[idx] )
- pool = (BtPool *)(bt->mgr->nodes + slot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
- else
- return NULL;
-
- page_no &= ~bt->mgr->poolmask;
-
- while( pool->basepage != page_no )
- if( pool = pool->hashnext )
- continue;
- else
- return NULL;
-
- return pool;
-}
-
-// add segment to hash table
-
-void bt_linkhash(BtDb *bt, BtPool *pool, uid page_no, int idx)
-{
-BtPool *node;
-uint slot;
-
- pool->hashprev = pool->hashnext = NULL;
- pool->basepage = page_no & ~bt->mgr->poolmask;
- pool->lru = 1;
-
- if( slot = bt->mgr->hash[idx] ) {
- node = (BtPool *)(bt->mgr->nodes + slot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
- pool->hashnext = node;
- node->hashprev = pool;
- }
-
- bt->mgr->hash[idx] = pool->slot;
-}
-
-// find best segment to evict from buffer pool
-
-BtPool *bt_findlru (BtDb *bt, uint hashslot)
-{
-unsigned long long int target = ~0LL;
-BtPool *pool = NULL, *node;
-
- if( !hashslot )
- return NULL;
-
- node = (BtPool *)(bt->mgr->nodes + hashslot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
-
- // scan pool entries under hash table slot
-
- do {
- if( node->pin )
- continue;
- if( node->lru > target )
- continue;
- target = node->lru;
- pool = node;
- } while( node = node->hashnext );
-
- return pool;
-}
-
-// map new buffer pool segment to virtual memory
-
-BTERR bt_mapsegment(BtDb *bt, BtPool *pool, uid page_no)
-{
-off64_t off = (page_no & ~bt->mgr->poolmask) << bt->mgr->page_bits;
-off64_t limit = off + ((bt->mgr->poolmask+1) << bt->mgr->page_bits);
-int flag;
-
-#ifdef unix
- flag = PROT_READ | ( bt->mgr->mode == BT_ro ? 0 : PROT_WRITE );
- pool->map = mmap (0, (bt->mgr->poolmask+1) << bt->mgr->page_bits, flag, MAP_SHARED, bt->mgr->idx, off);
- if( pool->map == MAP_FAILED )
- return bt->err = BTERR_map;
- // clear out madvise issued bits
- memset (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8) / 8), 0, (bt->mgr->poolmask + 8)/8);
-#else
- flag = ( bt->mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
- pool->hmap = CreateFileMapping(bt->mgr->idx, NULL, flag, (DWORD)(limit >> 32), (DWORD)limit, NULL);
- if( !pool->hmap )
- return bt->err = BTERR_map;
-
- flag = ( bt->mgr->mode == BT_ro ? FILE_MAP_READ : FILE_MAP_WRITE );
- pool->map = MapViewOfFile(pool->hmap, flag, (DWORD)(off >> 32), (DWORD)off, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
- if( !pool->map )
- return bt->err = BTERR_map;
-#endif
- return bt->err = 0;
-}
-
-// find or place requested page in segment-pool
-// return pool table entry, incrementing pin
-
-BtPool *bt_pinpage(BtDb *bt, uid page_no)
-{
-BtPool *pool, *node, *next;
-uint slot, idx, victim;
-BtLatchSet *set;
-
- // lock hash table chain
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx]);
-
- // look up in hash table
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releaseread (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // upgrade to write lock
-
- bt_releaseread (&bt->mgr->latch[idx]);
- bt_writelock (&bt->mgr->latch[idx]);
-
- // try to find page in pool with write lock
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // allocate a new pool node
- // and add to hash table
-
-#ifdef unix
- slot = __sync_fetch_and_add(&bt->mgr->poolcnt, 1);
-#else
- slot = _InterlockedIncrement (&bt->mgr->poolcnt) - 1;
-#endif
-
- if( ++slot < bt->mgr->poolmax ) {
- pool = (BtPool *)(bt->mgr->nodes + slot * (sizeof(BtPool) + (bt->mgr->poolmask + 1) * sizeof(BtLatchSet)));
- pool->slot = slot;
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-
- // pool table is full
- // find best pool entry to evict
-
-#ifdef unix
- __sync_fetch_and_add(&bt->mgr->poolcnt, -1);
-#else
- _InterlockedDecrement (&bt->mgr->poolcnt);
-#endif
-
- while( 1 ) {
-#ifdef unix
- victim = __sync_fetch_and_add(&bt->mgr->evicted, 1);
-#else
- victim = _InterlockedIncrement (&bt->mgr->evicted) - 1;
-#endif
- victim %= bt->mgr->hashsize;
-
- // try to get write lock
- // skip entry if not obtained
-
- if( !bt_writetry (&bt->mgr->latch[victim]) )
- continue;
-
- // if cache entry is empty
- // or no slots are unpinned
- // skip this entry
-
- if( !(pool = bt_findlru(bt, bt->mgr->hash[victim])) ) {
- bt_releasewrite (&bt->mgr->latch[victim]);
- continue;
- }
-
- // unlink victim pool node from hash table
-
- if( node = pool->hashprev )
- node->hashnext = pool->hashnext;
- else if( node = pool->hashnext )
- bt->mgr->hash[victim] = node->slot;
- else
- bt->mgr->hash[victim] = 0;
-
- if( node = pool->hashnext )
- node->hashprev = pool->hashprev;
-
- bt_releasewrite (&bt->mgr->latch[victim]);
-
- // remove old file mapping
-#ifdef unix
- munmap (pool->map, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
-#else
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
-#endif
- pool->map = NULL;
-
- // create new pool mapping
- // and link into hash table
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-}
-
-// place write, read, or parent lock on requested page_no.
-// pin to buffer pool and return page pointer
-
-BTERR bt_lockpage(BtDb *bt, uid page_no, BtLock mode, BtPage *pageptr)
-{
-BtLatchSet *set;
-BtPool *pool;
-uint subpage;
-BtPage page;
-
- // find/create maping in pool table
- // and pin our pool slot
-
- if( pool = bt_pinpage(bt, page_no) )
- subpage = (uint)(page_no & bt->mgr->poolmask); // page within mapping
- else
- return bt->err;
-
- set = pool->pagelatch + subpage;
- page = (BtPage)(pool->map + (subpage << bt->mgr->page_bits));
-#ifdef unix
- {
- uint idx = subpage / 8;
- uint bit = subpage % 8;
-
- if( ~((bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] >> bit) & 1 ) {
- madvise (page, bt->mgr->page_size, MADV_WILLNEED);
- (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] |= 1 << bit;
- }
- }
-#endif
-
- switch( mode ) {
- case BtLockRead:
- bt_readlock (set->readwr);
- break;
- case BtLockWrite:
- bt_writelock (set->readwr);
- break;
- case BtLockAccess:
- bt_readlock (set->access);
- break;
- case BtLockDelete:
- bt_writelock (set->access);
- break;
- case BtLockParent:
- bt_writelock (set->parent);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
- if( pageptr )
- *pageptr = page;
-
- return bt->err = 0;
-}
-
-// remove write, read, or parent lock on requested page_no.
-
-BTERR bt_unlockpage(BtDb *bt, uid page_no, BtLock mode)
-{
-uint subpage, idx;
-BtLatchSet *set;
-BtPool *pool;
-
- // since page is pinned
- // it should still be in the buffer pool
- // and is in no danger of being a victim for reuse
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx]);
-
- if( pool = bt_findpool(bt, page_no, idx) )
- subpage = (uint)(page_no & bt->mgr->poolmask);
- else
- return bt->err = BTERR_hash;
-
- bt_releaseread (&bt->mgr->latch[idx]);
- set = pool->pagelatch + subpage;
-
- switch( mode ) {
- case BtLockRead:
- bt_releaseread (set->readwr);
- break;
- case BtLockWrite:
- bt_releasewrite (set->readwr);
- break;
- case BtLockAccess:
- bt_releaseread (set->access);
- break;
- case BtLockDelete:
- bt_releasewrite (set->access);
- break;
- case BtLockParent:
- bt_releasewrite (set->parent);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, -1);
-#else
- _InterlockedDecrement (&pool->pin);
-#endif
- return bt->err = 0;
-}
-
-// deallocate a deleted page
-// place on free chain out of allocator page
-
-BTERR bt_freepage(BtDb *bt, uid page_no)
-{
- // obtain delete lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- // obtain write lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // lock allocation page
-
- if ( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return bt->err;
-
- // store chain in second right
- bt_putid(bt->temp->right, bt_getid(bt->alloc[1].right));
- bt_putid(bt->alloc[1].right, page_no);
-
- // unlock page zero
-
- if( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return bt->err;
-
- // remove write lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // remove delete lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockDelete) )
- return bt->err;
-
- return 0;
-}
-
-// allocate a new page and write page into it
-
-uid bt_newpage(BtDb *bt, BtPage page)
-{
-uid new_page;
-BtPage pmap;
-int reuse;
-
- // lock page zero
-
- if ( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return 0;
-
- // use empty chain first
- // else allocate empty page
-
- if( new_page = bt_getid(bt->alloc[1].right) ) {
- if( bt_lockpage (bt, new_page, BtLockWrite, &bt->temp) )
- return 0;
- bt_putid(bt->alloc[1].right, bt_getid(bt->temp->right));
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
- reuse = 1;
- } else {
- new_page = bt_getid(bt->alloc->right);
- bt_putid(bt->alloc->right, new_page+1);
- reuse = 0;
- }
-#ifdef unix
- if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
-
- // if writing first page of pool block, zero last page in the block
-
- if ( !reuse && bt->mgr->poolmask > 0 && (new_page & bt->mgr->poolmask) == 0 )
- {
- // use zero buffer to write zeros
- memset(bt->zero, 0, bt->mgr->page_size);
- if ( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->poolmask) << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
- }
-#else
- // bring new page into pool and copy page.
- // this will extend the file into the new pages.
-
- if( bt_lockpage(bt, new_page, BtLockWrite, &pmap) )
- return 0;
-
- memcpy(pmap, page, bt->mgr->page_size);
-
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
-#endif
- // unlock page zero
-
- if ( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return 0;
-
- return new_page;
-}
-
-// find slot in page for given key at a given level
-
-int bt_findslot (BtDb *bt, unsigned char *key, uint len)
-{
-uint diff, higher = bt->page->cnt, low = 1, slot;
-
- // low is the lowest candidate, higher is already
- // tested as .ge. the given key, loop ends when they meet
-
- while( diff = higher - low ) {
- slot = low + ( diff >> 1 );
- if( keycmp (keyptr(bt->page, slot), key, len) < 0 )
- low = slot + 1;
- else
- higher = slot;
- }
-
- return higher;
-}
-
-// find and load page at given level for given key
-// leave page rd or wr locked as requested
-
-int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, uint lock)
-{
-uid page_no = ROOT_page, prevpage = 0;
-uint drill = 0xff, slot;
-uint mode, prevmode;
-
- // start at root of btree and drill down
-
- do {
- // determine lock mode of drill level
- mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead;
-
- bt->page_no = page_no;
-
- // obtain access lock using lock chaining with Access mode
-
- if( page_no > ROOT_page )
- if( bt_lockpage(bt, page_no, BtLockAccess, NULL) )
- return 0;
-
- if( prevpage )
- if( bt_unlockpage(bt, prevpage, prevmode) )
- return 0;
-
- // obtain read lock using lock chaining
- // and pin page contents
-
- if( bt_lockpage(bt, page_no, mode, &bt->page) )
- return 0;
-
- if( page_no > ROOT_page )
- if( bt_unlockpage(bt, page_no, BtLockAccess) )
- return 0;
-
- // re-read and re-lock root after determining actual level of root
-
- if( bt->page_no == ROOT_page )
- if( bt->page->lvl != drill) {
- drill = bt->page->lvl;
-
- if( lock == BtLockWrite && drill == lvl )
- if( bt_unlockpage(bt, page_no, mode) )
- return 0;
- else
- continue;
- }
-
- // if page is being deleted,
- // move back to preceeding page
-
- if( bt->page->kill ) {
- page_no = bt_getid (bt->page->right);
- continue;
- }
-
- // find key on page at this level
- // and descend to requested level
-
- slot = bt_findslot (bt, key, len);
-
- // is this slot a foster child?
-
- if( slot <= bt->page->cnt - bt->page->foster )
- if( drill == lvl )
- return slot;
- else
- drill--;
-
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
- continue;
- else
- return bt->err = BTERR_struct, 0;
-
- // continue down / right using overlapping locks
- // to protect pages being killed or split.
-
- prevmode = mode;
- prevpage = bt->page_no;
- page_no = bt_getid(slotptr(bt->page, slot)->id);
- } while( page_no );
-
- // return error on end of chain
-
- bt->err = BTERR_struct;
- return 0; // return error
-}
-
-// find and delete key on page by marking delete flag bit
-// when page becomes empty, delete it from the btree
-
-BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl)
-{
-unsigned char leftkey[256], rightkey[256];
-uid page_no, right;
-uint slot, tod;
-BtKey ptr;
-
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // if key is found delete it, otherwise ignore request
-
- if( !keycmp (ptr, key, len) )
- if( slotptr(bt->page, slot)->dead == 0 ) {
- slotptr(bt->page,slot)->dead = 1;
- if( slot < bt->page->cnt )
- bt->page->dirty = 1;
- bt->page->act--;
- }
-
- // return if page is not empty, or it has no right sibling
-
- right = bt_getid(bt->page->right);
- page_no = bt->page_no;
-
- if( !right || bt->page->act )
- return bt_unlockpage(bt, page_no, BtLockWrite);
-
- // obtain Parent lock over write lock
-
- if( bt_lockpage(bt, page_no, BtLockParent, NULL) )
- return bt->err;
-
- // cache copy of key to delete
-
- ptr = keyptr(bt->page, bt->page->cnt);
- memcpy(leftkey, ptr, ptr->len + 1);
-
- // lock and map right page
-
- if ( bt_lockpage(bt, right, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // pull contents of next page into current empty page
- memcpy (bt->page, bt->temp, bt->mgr->page_size);
-
- // cache copy of key to update
- ptr = keyptr(bt->temp, bt->temp->cnt);
- memcpy(rightkey, ptr, ptr->len + 1);
-
- // Mark right page as deleted and point it to left page
- // until we can post updates at higher level.
-
- bt_putid(bt->temp->right, page_no);
- bt->temp->kill = 1;
- bt->temp->cnt = 0;
-
- if( bt_unlockpage(bt, right, BtLockWrite) )
- return bt->err;
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // delete old lower key to consolidated node
-
- if( bt_deletekey (bt, leftkey + 1, *leftkey, lvl + 1) )
- return bt->err;
-
- // redirect higher key directly to consolidated node
-
- if( slot = bt_loadpage (bt, rightkey+1, *rightkey, lvl+1, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // since key already exists, update id
-
- if( keycmp (ptr, rightkey+1, *rightkey) )
- return bt->err = BTERR_struct;
-
- slotptr(bt->page, slot)->dead = 0;
- bt_putid(slotptr(bt->page,slot)->id, page_no);
- bt_unlockpage(bt, bt->page_no, BtLockWrite);
-
- // obtain write lock and
- // add right block to free chain
-
- if( bt_freepage (bt, right) )
- return bt->err;
-
- // remove ParentModify lock
-
- if( bt_unlockpage(bt, page_no, BtLockParent) )
- return bt->err;
-
- return 0;
-}
-
-// find key in leaf level and return row-id
-
-uid bt_findkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-BtKey ptr;
-uid id;
-
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- ptr = keyptr(bt->page, slot);
- else
- return 0;
-
- // if key exists, return row-id
- // otherwise return 0
-
- if( ptr->len == len && !memcmp (ptr->key, key, len) )
- id = bt_getid(slotptr(bt->page,slot)->id);
- else
- id = 0;
-
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
-
- return id;
-}
-
-// check page for space available,
-// clean if necessary and return
-// 0 - page needs splitting
-// 1 - go ahead
-
-uint bt_cleanpage(BtDb *bt, uint amt)
-{
-uint nxt = bt->mgr->page_size;
-BtPage page = bt->page;
-uint cnt = 0, idx = 0;
-uint max = page->cnt;
-BtKey key;
-
- if( page->min >= (max+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- // skip cleanup if nothing to reclaim
-
- if( !page->dirty )
- return 0;
-
- memcpy (bt->frame, page, bt->mgr->page_size);
-
- // skip page info and set rest of page to zero
-
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- page->dirty = 0;
- page->act = 0;
-
- // try cleaning up page first
-
- while( cnt++ < max ) {
- // always leave fence key and foster children in list
- if( cnt < max - page->foster && slotptr(bt->frame,cnt)->dead )
- continue;
-
- // copy key
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
-
- // copy slot
- memcpy(slotptr(page, ++idx)->id, slotptr(bt->frame, cnt)->id, BtId);
- if( !(slotptr(page, idx)->dead = slotptr(bt->frame, cnt)->dead) )
- page->act++;
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // see if page has enough space now, or does it need splitting?
-
- if( page->min >= (idx+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- return 0;
-}
-
-// add key to page
-// return with page unlocked
-
-BTERR bt_addkeytopage (BtDb *bt, uint slot, unsigned char *key, uint len, uid id, uint tod)
-{
-BtPage page = bt->page;
-uint idx;
-
- // calculate next available slot and copy key into page
-
- page->min -= len + 1;
- ((unsigned char *)page)[page->min] = len;
- memcpy ((unsigned char *)page + page->min +1, key, len );
-
- for( idx = slot; idx < page->cnt; idx++ )
- if( slotptr(page, idx)->dead )
- break;
-
- // now insert key into array before slot
- // preserving the fence slot
-
- if( idx == page->cnt )
- idx++, page->cnt++;
-
- page->act++;
-
- while( idx > slot )
- *slotptr(page, idx) = *slotptr(page, idx -1), idx--;
-
- bt_putid(slotptr(page,slot)->id, id);
- slotptr(page, slot)->off = page->min;
- slotptr(page, slot)->tod = tod;
- slotptr(page, slot)->dead = 0;
-
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
-}
-
-// split the root and raise the height of the btree
-
-BTERR bt_splitroot(BtDb *bt, uid right)
-{
-uint nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-BtPage root = bt->page;
-uid new_page;
-BtKey key;
-
- // Obtain an empty page to use, and copy the left page
- // contents into it from the root. Strip foster child key.
- // (it's the stopper key)
-
- root->act--;
- root->cnt--;
- root->foster--;
-
- // Save left fence key.
-
- key = keyptr(root, root->cnt);
- memcpy (fencekey, key, key->len + 1);
-
- // copy the lower keys into a new left page
-
- if( !(new_page = bt_newpage(bt, root)) )
- return bt->err;
-
- // preserve the page info at the bottom
- // and set rest of the root to zero
-
- memset (root+1, 0, bt->mgr->page_size - sizeof(*root));
-
- // insert left fence key on empty newroot page
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 1)->id, new_page);
- slotptr(root, 1)->off = nxt;
-
- // insert stopper key on newroot page
- // and increase the root height
-
- nxt -= 3;
- fencekey[0] = 2;
- fencekey[1] = 0xff;
- fencekey[2] = 0xff;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 2)->id, right);
- slotptr(root, 2)->off = nxt;
-
- bt_putid(root->right, 0);
- root->min = nxt; // reset lowest used offset and key count
- root->cnt = 2;
- root->act = 2;
- root->lvl++;
-
- // release root (bt->page)
-
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
-}
-
-// split already locked full node
-// return unlocked.
-
-BTERR bt_splitpage (BtDb *bt)
-{
-uint slot, cnt, idx, max, nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-uid page_no = bt->page_no;
-BtPage page = bt->page;
-uint tod = time(NULL);
-uint lvl = page->lvl;
-uid new_page, right;
-BtKey key;
-
- // initialize frame buffer
-
- memset (bt->frame, 0, bt->mgr->page_size);
- max = page->cnt - page->foster;
- tod = (uint)time(NULL);
- cnt = max / 2;
- idx = 0;
-
- // split higher half of keys to bt->frame
- // leaving foster children in the left node.
-
- while( cnt++ < max ) {
- key = keyptr(page, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)bt->frame + nxt, key, key->len + 1);
- memcpy(slotptr(bt->frame,++idx)->id, slotptr(page,cnt)->id, BtId);
- slotptr(bt->frame, idx)->tod = slotptr(page, cnt)->tod;
- slotptr(bt->frame, idx)->off = nxt;
- bt->frame->act++;
- }
-
- // transfer right link node
-
- if( page_no > ROOT_page ) {
- right = bt_getid (page->right);
- bt_putid(bt->frame->right, right);
- }
-
- bt->frame->bits = bt->mgr->page_bits;
- bt->frame->min = nxt;
- bt->frame->cnt = idx;
- bt->frame->lvl = lvl;
-
- // get new free page and write frame to it.
-
- if( !(new_page = bt_newpage(bt, bt->frame)) )
- return bt->err;
-
- // remember fence key for new page to add
- // as foster child
-
- key = keyptr(bt->frame, idx);
- memcpy (fencekey, key, key->len + 1);
-
- // update lower keys and foster children to continue in old page
-
- memcpy (bt->frame, page, bt->mgr->page_size);
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- nxt = bt->mgr->page_size;
- page->act = 0;
- cnt = 0;
- idx = 0;
-
- // assemble page of smaller keys
- // to remain in the old page
-
- while( cnt++ < max / 2 ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- // insert new foster child at beginning of the current foster children
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)page + nxt, fencekey, *fencekey + 1);
- bt_putid (slotptr(page,++idx)->id, new_page);
- slotptr(page, idx)->tod = tod;
- slotptr(page, idx)->off = nxt;
- page->foster++;
- page->act++;
-
- // continue with old foster child keys if any
-
- cnt = bt->frame->cnt - bt->frame->foster;
-
- while( cnt++ < bt->frame->cnt ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // link new right page
-
- bt_putid (page->right, new_page);
-
- // if current page is the root page, split it
-
- if( page_no == ROOT_page )
- return bt_splitroot (bt, new_page);
-
- // release wr lock on page
-
- if( bt_unlockpage (bt, page_no, BtLockWrite) )
- return bt->err;
-
- // obtain ParentModification lock for current page
- // to fix fence key and highest foster child on page
-
- if( bt_lockpage (bt, page_no, BtLockParent, NULL) )
- return bt->err;
-
- // get our highest foster child key to find in parent node
-
- if( bt_lockpage (bt, page_no, BtLockRead, &page) )
- return bt->err;
-
- key = keyptr(page, page->cnt);
- memcpy (fencekey, key, key->len+1);
-
- if( bt_unlockpage (bt, page_no, BtLockRead) )
- return bt->err;
-
-try_again:
-
- do {
- slot = bt_loadpage (bt, fencekey + 1, *fencekey, lvl + 1, BtLockWrite);
-
- if( !slot )
- return bt->err;
-
- // check if parent page has enough space for any possible key
-
- if( bt_cleanpage (bt, 256) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- } while( 1 );
-
- // see if we are still a foster child from another node
-
- if( bt_getid (slotptr(bt->page, slot)->id) != page_no ) {
- bt_unlockpage (bt, bt->page_no, BtLockWrite);
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- goto try_again;
- }
-
- // wait until readers from parent get their locks
-
- if( bt_lockpage (bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- if( bt_lockpage (bt, page_no, BtLockWrite, &page) )
- return bt->err;
-
- // switch parent fence key to foster child
-
- if( slotptr(page, page->cnt)->dead )
- slotptr(bt->page, slot)->dead = 1;
- else
- bt_putid (slotptr(bt->page, slot)->id, bt_getid(slotptr(page, page->cnt)->id));
-
- // remove highest foster child from our page
- // add our new fence key to parent
-
- page->cnt--;
- page->act--;
- page->foster--;
- page->dirty = 1;
- key = keyptr(page, page->cnt);
-
- if( bt_addkeytopage (bt, slot, key->key, key->len, page_no, tod) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockDelete) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockWrite) )
- return bt->err;
-
- return bt_unlockpage (bt, page_no, BtLockParent);
-}
-
-// Insert new key into the btree at leaf level.
-
-BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod)
-{
-uint slot, idx;
-BtPage page;
-BtKey ptr;
-
- while( 1 ) {
- if( slot = bt_loadpage (bt, key, len, 0, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- {
- if ( !bt->err )
- bt->err = BTERR_ovflw;
- return bt->err;
- }
-
- // if key already exists, update id and return
-
- page = bt->page;
-
- if( !keycmp (ptr, key, len) ) {
- slotptr(page, slot)->dead = 0;
- slotptr(page, slot)->tod = tod;
- bt_putid(slotptr(page,slot)->id, id);
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
- }
-
- // check if page has enough space
-
- if( bt_cleanpage (bt, len) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- }
-
- return bt_addkeytopage (bt, slot, key, len, id, tod);
-}
-
-// cache page of keys into cursor and return starting slot for given key
-
-uint bt_startkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-
- // cache page for retrieval
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- memcpy (bt->cursor, bt->page, bt->mgr->page_size);
- bt->cursor_page = bt->page_no;
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
-
- return slot;
-}
-
-// return next slot for cursor page
-// or slide cursor right into next page
-
-uint bt_nextkey (BtDb *bt, uint slot)
-{
-BtPage page;
-uid right;
-
- do {
- right = bt_getid(bt->cursor->right);
- while( slot++ < bt->cursor->cnt - bt->cursor->foster )
- if( slotptr(bt->cursor,slot)->dead )
- continue;
- else if( right || (slot < bt->cursor->cnt - bt->cursor->foster) )
- return slot;
- else
- break;
-
- if( !right )
- break;
-
- bt->cursor_page = right;
-
- if( bt_lockpage(bt, right, BtLockRead, &page) )
- return 0;
-
- memcpy (bt->cursor, page, bt->mgr->page_size);
-
- if ( bt_unlockpage(bt, right, BtLockRead) )
- return 0;
-
- slot = 0;
- } while( 1 );
-
- return bt->err = 0;
-}
-
-BtKey bt_key(BtDb *bt, uint slot)
-{
- return keyptr(bt->cursor, slot);
-}
-
-uid bt_uid(BtDb *bt, uint slot)
-{
- return bt_getid(slotptr(bt->cursor,slot)->id);
-}
-
-uint bt_tod(BtDb *bt, uint slot)
-{
- return slotptr(bt->cursor,slot)->tod;
-}
-
-
-#ifdef STANDALONE
-
-typedef struct {
- char type, idx;
- char *infile;
- BtMgr *mgr;
- int num;
-} ThreadArg;
-
-// standalone program to index file of keys
-// then list them onto std-out
-
-#ifdef unix
-void *index_file (void *arg)
-#else
-uint __stdcall index_file (void *arg)
-#endif
-{
-int line = 0, found = 0, cnt = 0;
-uid next, page_no = LEAF_page; // start on first page of leaves
-unsigned char key[256];
-ThreadArg *args = arg;
-int ch, len = 0, slot;
-time_t tod[1];
-BtPage page;
-BtKey ptr;
-BtDb *bt;
-FILE *in;
-
- bt = bt_open (args->mgr);
- time (tod);
-
- switch(args->type | 0x20)
- {
- case 'w':
- fprintf(stderr, "started indexing for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
-
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_insertkey (bt, key, len, line, *tod) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys\n", args->infile, line);
- break;
-
- case 'd':
- fprintf(stderr, "started deleting keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_deletekey (bt, key, len, 0) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for keys, %d \n", args->infile, line);
- break;
-
- case 'f':
- fprintf(stderr, "started finding keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_findkey (bt, key, len) )
- found++;
- else if( bt->err )
- fprintf(stderr, "Error %d Syserr %d Line: %d\n", bt->err, errno, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys, found %d\n", args->infile, line, found);
- break;
-
- case 's':
- len = key[0] = 0;
-
- fprintf(stderr, "started reading\n");
-
- if( slot = bt_startkey (bt, key, len) )
- slot--;
- else
- fprintf(stderr, "Error %d in StartKey. Syserror: %d\n", bt->err, errno), exit(0);
-
- while( slot = bt_nextkey (bt, slot) ) {
- ptr = bt_key(bt, slot);
- fwrite (ptr->key, ptr->len, 1, stdout);
- fputc ('\n', stdout);
- }
-
- break;
-
- case 'c':
- fprintf(stderr, "started reading\n");
-
- do {
- bt_lockpage (bt, page_no, BtLockRead, &page);
- cnt += page->act;
- next = bt_getid (page->right);
- bt_unlockpage (bt, page_no, BtLockRead);
- } while( page_no = next );
-
- cnt--; // remove stopper key
- fprintf(stderr, " Total keys read %d\n", cnt);
- break;
- }
-
- bt_close (bt);
-#ifdef unix
- return NULL;
-#else
- return 0;
-#endif
-}
-
-typedef struct timeval timer;
-
-int main (int argc, char **argv)
-{
-int idx, cnt, len, slot, err;
-int segsize, bits = 16;
-#ifdef unix
-pthread_t *threads;
-timer start, stop;
-#else
-time_t start[1], stop[1];
-HANDLE *threads;
-#endif
-double real_time;
-ThreadArg *args;
-uint poolsize = 0;
-int num = 0;
-char key[1];
-BtMgr *mgr;
-BtKey ptr;
-BtDb *bt;
-
- if( argc < 3 ) {
- fprintf (stderr, "Usage: %s idx_file Read/Write/Scan/Delete/Find [page_bits mapped_segments seg_bits line_numbers src_file1 src_file2 ... ]\n", argv[0]);
- fprintf (stderr, " where page_bits is the page size in bits\n");
- fprintf (stderr, " mapped_segments is the number of mmap segments in buffer pool\n");
- fprintf (stderr, " seg_bits is the size of individual segments in buffer pool in pages in bits\n");
- fprintf (stderr, " line_numbers = 1 to append line numbers to keys\n");
- fprintf (stderr, " src_file1 thru src_filen are files of keys separated by newline\n");
- exit(0);
- }
-
-#ifdef unix
- gettimeofday(&start, NULL);
-#else
- time(start);
-#endif
-
- if( argc > 3 )
- bits = atoi(argv[3]);
-
- if( argc > 4 )
- poolsize = atoi(argv[4]);
-
- if( !poolsize )
- fprintf (stderr, "Warning: no mapped_pool\n");
-
- if( poolsize > 65535 )
- fprintf (stderr, "Warning: mapped_pool > 65535 segments\n");
-
- if( argc > 5 )
- segsize = atoi(argv[5]);
- else
- segsize = 4; // 16 pages per mmap segment
-
- if( argc > 6 )
- num = atoi(argv[6]);
-
- cnt = argc - 7;
-#ifdef unix
- threads = malloc (cnt * sizeof(pthread_t));
-#else
- threads = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, cnt * sizeof(HANDLE));
-#endif
- args = malloc (cnt * sizeof(ThreadArg));
-
- mgr = bt_mgr ((argv[1]), BT_rw, bits, poolsize, segsize, poolsize / 8);
-
- if( !mgr ) {
- fprintf(stderr, "Index Open Error %s\n", argv[1]);
- exit (1);
- }
-
- // fire off threads
-
- for( idx = 0; idx < cnt; idx++ ) {
- args[idx].infile = argv[idx + 7];
- args[idx].type = argv[2][0];
- args[idx].mgr = mgr;
- args[idx].num = num;
- args[idx].idx = idx;
-#ifdef unix
- if( err = pthread_create (threads + idx, NULL, index_file, args + idx) )
- fprintf(stderr, "Error creating thread %d\n", err);
-#else
- threads[idx] = (HANDLE)_beginthreadex(NULL, 65536, index_file, args + idx, 0, NULL);
-#endif
- }
-
- // wait for termination
-
-#ifdef unix
- for( idx = 0; idx < cnt; idx++ )
- pthread_join (threads[idx], NULL);
- gettimeofday(&stop, NULL);
- real_time = 1000.0 * ( stop.tv_sec - start.tv_sec ) + 0.001 * (stop.tv_usec - start.tv_usec );
-#else
- WaitForMultipleObjects (cnt, threads, TRUE, INFINITE);
-
- for( idx = 0; idx < cnt; idx++ )
- CloseHandle(threads[idx]);
-
- time (stop);
- real_time = 1000 * (*stop - *start);
-#endif
- fprintf(stderr, " Time to complete: %.2f seconds\n", real_time/1000);
- bt_mgrclose (mgr);
-}
-
-#endif //STANDALONE
+++ /dev/null
-// foster btree version e
-// 17 JAN 2014
-
-// author: karl malbrain, malbrain@cal.berkeley.edu
-
-/*
-This work, including the source code, documentation
-and related data, is placed into the public domain.
-
-The orginal author is Karl Malbrain.
-
-THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
-OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
-MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
-ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
-RESULTING FROM THE USE, MODIFICATION, OR
-REDISTRIBUTION OF THIS SOFTWARE.
-*/
-
-// Please see the project home page for documentation
-// code.google.com/p/high-concurrency-btree
-
-#define _FILE_OFFSET_BITS 64
-#define _LARGEFILE64_SOURCE
-
-#ifdef linux
-#define _GNU_SOURCE
-#endif
-
-#ifdef unix
-#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <sys/time.h>
-#include <sys/mman.h>
-#include <errno.h>
-#include <pthread.h>
-#else
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <fcntl.h>
-#include <process.h>
-#include <intrin.h>
-#endif
-
-#include <memory.h>
-#include <string.h>
-
-typedef unsigned long long uid;
-
-#ifndef unix
-typedef unsigned long long off64_t;
-typedef unsigned short ushort;
-typedef unsigned int uint;
-#endif
-
-#define BT_ro 0x6f72 // ro
-#define BT_rw 0x7772 // rw
-
-#define BT_latchtable 128 // number of latch manager slots
-
-#define BT_maxbits 24 // maximum page size in bits
-#define BT_minbits 9 // minimum page size in bits
-#define BT_minpage (1 << BT_minbits) // minimum page size
-#define BT_maxpage (1 << BT_maxbits) // maximum page size
-
-/*
-There are five lock types for each node in three independent sets:
-1. (set 1) AccessIntent: Sharable. Going to Read the node. Incompatible with NodeDelete.
-2. (set 1) NodeDelete: Exclusive. About to release the node. Incompatible with AccessIntent.
-3. (set 2) ReadLock: Sharable. Read the node. Incompatible with WriteLock.
-4. (set 2) WriteLock: Exclusive. Modify the node. Incompatible with ReadLock and other WriteLocks.
-5. (set 3) ParentLock: Exclusive. Have parent adopt/delete maximum foster child from the node.
-*/
-
-typedef enum{
- BtLockAccess,
- BtLockDelete,
- BtLockRead,
- BtLockWrite,
- BtLockParent,
- BtLockPin
-}BtLock;
-
-// Define the length of the page and key pointers
-
-#define BtId 6
-
-// Page key slot definition.
-
-// If BT_maxbits is 15 or less, you can save 4 bytes
-// for each key stored by making the first two uints
-// into ushorts. You can also save 4 bytes by removing
-// the tod field from the key.
-
-// Keys are marked dead, but remain on the page until
-// it cleanup is called. The fence key (highest key) for
-// the page is always present, even after cleanup.
-
-typedef struct {
- uint off:BT_maxbits; // page offset for key start
- uint dead:1; // set for deleted key
- uint tod; // time-stamp for key
- unsigned char id[BtId]; // id associated with key
-} BtSlot;
-
-// The key structure occupies space at the upper end of
-// each page. It's a length byte followed by the value
-// bytes.
-
-typedef struct {
- unsigned char len;
- unsigned char key[1];
-} *BtKey;
-
-// The first part of an index page.
-// It is immediately followed
-// by the BtSlot array of keys.
-
-typedef struct Page {
- uint cnt; // count of keys in page
- uint act; // count of active keys
- uint min; // next key offset
- uint foster; // count of foster children
- unsigned char bits; // page size in bits
- unsigned char lvl:6; // level of page
- unsigned char kill:1; // page is being deleted
- unsigned char dirty:1; // page needs to be cleaned
- unsigned char right[BtId]; // page number to right
-} *BtPage;
-
-// mode & definition for hash latch implementation
-
-enum {
- Mutex = 1,
- Write = 2,
- Pending = 4,
- Share = 8
-} LockMode;
-
-// mutex locks the other fields
-// exclusive is set for write access
-// share is count of read accessors
-
-typedef struct {
- volatile ushort mutex:1;
- volatile ushort exclusive:1;
- volatile ushort pending:1;
- volatile ushort share:13;
-} BtSpinLatch;
-
-// hash table entries
-
-typedef struct {
- BtSpinLatch latch[1];
- volatile ushort slot; // Latch table entry at head of chain
-} BtHashEntry;
-
-// latch table lock structure
-// implements a fair read-write lock
-
-typedef struct {
-#ifdef unix
- pthread_rwlock_t lock[1];
-#else
- SRWLOCK srw[1];
-#endif
-} BtLatch;
-
-typedef struct {
- BtLatch readwr[1]; // read/write page lock
- BtLatch access[1]; // Access Intent/Page delete
- BtLatch parent[1]; // adoption of foster children
- BtSpinLatch busy[1]; // slot is being moved between chains
- volatile ushort next; // next entry in hash table chain
- volatile ushort prev; // prev entry in hash table chain
- volatile ushort pin; // number of outstanding locks
- volatile ushort hash; // hash slot entry is under
- volatile uid page_no; // latch set page number
-} BtLatchSet;
-
-// The memory mapping pool table buffer manager entry
-
-typedef struct {
- unsigned long long int lru; // number of times accessed
- uid basepage; // mapped base page number
- char *map; // mapped memory pointer
- ushort pin; // mapped page pin counter
- ushort slot; // slot index in this array
- void *hashprev; // previous pool entry for the same hash idx
- void *hashnext; // next pool entry for the same hash idx
-#ifndef unix
- HANDLE hmap; // Windows memory mapping handle
-#endif
-} BtPool;
-
-// structure for latch manager on ALLOC_page
-
-typedef struct {
- struct Page alloc[2]; // next & free page_nos in right ptr
- BtSpinLatch lock[1]; // allocation area lite latch
- ushort latchdeployed; // highest number of latch entries deployed
- ushort nlatchpage; // number of latch pages at BT_latch
- ushort latchtotal; // number of page latch entries
- ushort latchhash; // number of latch hash table slots
- ushort latchvictim; // next latch entry to examine
- BtHashEntry table[0]; // the hash table
-} BtLatchMgr;
-
-// The object structure for Btree access
-
-typedef struct {
- uint page_size; // page size
- uint page_bits; // page size in bits
- uint seg_bits; // seg size in pages in bits
- uint mode; // read-write mode
-#ifdef unix
- int idx;
- char *pooladvise; // bit maps for pool page advisements
-#else
- HANDLE idx;
-#endif
- ushort poolcnt; // highest page pool node in use
- ushort poolmax; // highest page pool node allocated
- ushort poolmask; // total size of pages in mmap segment - 1
- ushort hashsize; // size of Hash Table for pool entries
- ushort evicted; // last evicted hash table slot
- ushort *hash; // hash table of pool entries
- BtPool *pool; // memory pool page segments
- BtSpinLatch *latch; // latches for pool hash slots
- BtLatchMgr *latchmgr; // mapped latch page from allocation page
- BtLatchSet *latchsets; // mapped latch set from latch pages
-#ifndef unix
- HANDLE halloc; // allocation and latch table handle
-#endif
-} BtMgr;
-
-typedef struct {
- BtMgr *mgr; // buffer manager for thread
- BtPage temp; // temporary frame buffer (memory mapped/file IO)
- BtPage cursor; // cached frame for start/next (never mapped)
- BtPage frame; // spare frame for the page split (never mapped)
- BtPage zero; // page frame for zeroes at end of file
- BtPage page; // current page
- uid page_no; // current page number
- uid cursor_page; // current cursor page number
- BtLatchSet *set; // current page latch set
- unsigned char *mem; // frame, cursor, page memory buffer
- int err; // last error
-} BtDb;
-
-typedef enum {
- BTERR_ok = 0,
- BTERR_struct,
- BTERR_ovflw,
- BTERR_lock,
- BTERR_map,
- BTERR_wrt,
- BTERR_hash,
- BTERR_latch
-} BTERR;
-
-// B-Tree functions
-extern void bt_close (BtDb *bt);
-extern BtDb *bt_open (BtMgr *mgr);
-extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod);
-extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
-extern uid bt_findkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_nextkey (BtDb *bt, uint slot);
-
-// manager functions
-extern BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolsize, uint segsize, uint hashsize);
-void bt_mgrclose (BtMgr *mgr);
-
-// Helper functions to return cursor slot values
-
-extern BtKey bt_key (BtDb *bt, uint slot);
-extern uid bt_uid (BtDb *bt, uint slot);
-extern uint bt_tod (BtDb *bt, uint slot);
-
-// BTree page number constants
-#define ALLOC_page 0 // allocation & lock manager hash table
-#define ROOT_page 1 // root of the btree
-#define LEAF_page 2 // first page of leaves
-#define LATCH_page 3 // pages for lock manager
-
-// Number of levels to create in a new BTree
-
-#define MIN_lvl 2
-
-// The page is allocated from low and hi ends.
-// The key offsets and row-id's are allocated
-// from the bottom, while the text of the key
-// is allocated from the top. When the two
-// areas meet, the page is split into two.
-
-// A key consists of a length byte, two bytes of
-// index number (0 - 65534), and up to 253 bytes
-// of key value. Duplicate keys are discarded.
-// Associated with each key is a 48 bit row-id.
-
-// The b-tree root is always located at page 1.
-// The first leaf page of level zero is always
-// located on page 2.
-
-// When to root page fills, it is split in two and
-// the tree height is raised by a new root at page
-// one with two keys.
-
-// Deleted keys are marked with a dead bit until
-// page cleanup The fence key for a node is always
-// present, even after deletion and cleanup.
-
-// Groups of pages called segments from the btree are
-// cached with memory mapping. A hash table is used to keep
-// track of the cached segments. This behaviour is controlled
-// by the cache block size parameter to bt_open.
-
-// To achieve maximum concurrency one page is locked at a time
-// as the tree is traversed to find leaf key in question.
-
-// An adoption traversal leaves the parent node locked as the
-// tree is traversed to the level in quesiton.
-
-// Page 0 is dedicated to lock for new page extensions,
-// and chains empty pages together for reuse.
-
-// Empty pages are chained together through the ALLOC page and reused.
-
-// Access macros to address slot and key values from the page
-
-#define slotptr(page, slot) (((BtSlot *)(page+1)) + (slot-1))
-#define keyptr(page, slot) ((BtKey)((unsigned char*)(page) + slotptr(page, slot)->off))
-
-void bt_putid(unsigned char *dest, uid id)
-{
-int i = BtId;
-
- while( i-- )
- dest[i] = (unsigned char)id, id >>= 8;
-}
-
-uid bt_getid(unsigned char *src)
-{
-uid id = 0;
-int i;
-
- for( i = 0; i < BtId; i++ )
- id <<= 8, id |= *src++;
-
- return id;
-}
-
-// wait until write lock mode is clear
-// and add 1 to the share count
-
-void bt_spinreadlock(BtSpinLatch *latch)
-{
-ushort prev;
-
- do {
-#ifdef unix
- while( __sync_fetch_and_or((ushort *)latch, Mutex) & Mutex )
- sched_yield();
-#else
- while( _InterlockedOr16((ushort *)latch, Mutex) & Mutex )
- SwitchToThread();
-#endif
-
- // see if exclusive request is granted or pending
-
- if( prev = !(latch->exclusive | latch->pending) )
-#ifdef unix
- __sync_fetch_and_add((ushort *)latch, Share);
-#else
- _InterlockedExchangeAdd16 ((ushort *)latch, Share);
-#endif
-
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
-#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
-#endif
- if( prev )
- return;
-#ifdef unix
- } while( sched_yield(), 1 );
-#else
- } while( SwitchToThread(), 1 );
-#endif
-}
-
-// wait for other read and write latches to relinquish
-
-void bt_spinwritelock(BtSpinLatch *latch)
-{
-ushort prev;
-
- do {
-#ifdef unix
- while( __sync_fetch_and_or((ushort *)latch, Mutex | Pending) & Mutex )
- sched_yield();
-#else
- while( _InterlockedOr16((ushort *)latch, Mutex | Pending) & Mutex )
- SwitchToThread();
-#endif
- if( prev = !(latch->share | latch->exclusive) )
-#ifdef unix
- __sync_fetch_and_or((ushort *)latch, Write);
-#else
- _InterlockedOr16((ushort *)latch, Write);
-#endif
-
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~(Mutex | Pending));
-#else
- _InterlockedAnd16((ushort *)latch, ~(Mutex | Pending));
-#endif
- if( prev )
- return;
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- } while( 1 );
-}
-
-// try to obtain write lock
-
-// return 1 if obtained,
-// 0 otherwise
-
-int bt_spinwritetry(BtSpinLatch *latch)
-{
-ushort prev;
-
-#ifdef unix
- if( prev = __sync_fetch_and_or((ushort *)latch, Mutex), prev & Mutex )
- return 0;
-#else
- if( prev = _InterlockedOr16((ushort *)latch, Mutex), prev & Mutex )
- return 0;
-#endif
- // take write access if all bits are clear
-
- if( !prev )
-#ifdef unix
- __sync_fetch_and_or ((ushort *)latch, Write);
-#else
- _InterlockedOr16((ushort *)latch, Write);
-#endif
-
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
-#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
-#endif
- return !prev;
-}
-
-// clear write mode
-
-void bt_spinreleasewrite(BtSpinLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Write);
-#else
- _InterlockedAnd16((ushort *)latch, ~Write);
-#endif
-}
-
-// decrement reader count
-
-void bt_spinreleaseread(BtSpinLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_add((ushort *)latch, -Share);
-#else
- _InterlockedExchangeAdd16 ((ushort *)latch, -Share);
-#endif
-}
-
-void bt_initlockset (BtLatchSet *set)
-{
-#ifdef unix
-pthread_rwlockattr_t rwattr[1];
-
- pthread_rwlockattr_init (rwattr);
- pthread_rwlockattr_setkind_np (rwattr, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
- pthread_rwlockattr_setpshared (rwattr, PTHREAD_PROCESS_SHARED);
-
- pthread_rwlock_init (set->readwr->lock, rwattr);
- pthread_rwlock_init (set->access->lock, rwattr);
- pthread_rwlock_init (set->parent->lock, rwattr);
- pthread_rwlockattr_destroy (rwattr);
-#else
- InitializeSRWLock (set->readwr->srw);
- InitializeSRWLock (set->access->srw);
- InitializeSRWLock (set->parent->srw);
-#endif
-}
-
-// link latch table entry into latch hash table
-
-void bt_latchlink (BtDb *bt, ushort hashidx, ushort victim, uid page_no)
-{
-BtLatchSet *set = bt->mgr->latchsets + victim;
-
- if( set->next = bt->mgr->latchmgr->table[hashidx].slot )
- bt->mgr->latchsets[set->next].prev = victim;
-
- bt->mgr->latchmgr->table[hashidx].slot = victim;
- set->page_no = page_no;
- set->hash = hashidx;
- set->prev = 0;
-}
-
-// find existing latchset or inspire new one
-// return with latchset pinned
-
-BtLatchSet *bt_bindlatch (BtDb *bt, uid page_no, int incr)
-{
-ushort hashidx = page_no % bt->mgr->latchmgr->latchhash;
-ushort slot, avail = 0, victim, idx;
-BtLatchSet *set;
-
- // obtain read lock on hash table entry
-
- bt_spinreadlock(bt->mgr->latchmgr->table[hashidx].latch);
-
- if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
- {
- set = bt->mgr->latchsets + slot;
- if( page_no == set->page_no )
- break;
- } while( slot = set->next );
-
- if( slot && incr ) {
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- }
-
- bt_spinreleaseread (bt->mgr->latchmgr->table[hashidx].latch);
-
- if( slot )
- return set;
-
- // try again, this time with write lock
-
- bt_spinwritelock(bt->mgr->latchmgr->table[hashidx].latch);
-
- if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
- {
- set = bt->mgr->latchsets + slot;
- if( page_no == set->page_no )
- break;
- if( !set->pin && !avail )
- avail = slot;
- } while( slot = set->next );
-
- // found our entry, or take over an unpinned one
-
- if( slot || (slot = avail) ) {
- set = bt->mgr->latchsets + slot;
- if( incr )
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- set->page_no = page_no;
- bt_spinreleasewrite(bt->mgr->latchmgr->table[hashidx].latch);
- return set;
- }
-
- // see if there are any unused entries
-#ifdef unix
- victim = __sync_fetch_and_add (&bt->mgr->latchmgr->latchdeployed, 1) + 1;
-#else
- victim = _InterlockedIncrement16 (&bt->mgr->latchmgr->latchdeployed);
-#endif
-
- if( victim < bt->mgr->latchmgr->latchtotal ) {
- set = bt->mgr->latchsets + victim;
- if( incr )
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- bt_initlockset (set);
- bt_latchlink (bt, hashidx, victim, page_no);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch);
- return set;
- }
-
-#ifdef unix
- victim = __sync_fetch_and_add (&bt->mgr->latchmgr->latchdeployed, -1);
-#else
- victim = _InterlockedDecrement16 (&bt->mgr->latchmgr->latchdeployed);
-#endif
- // find and reuse previous lock entry
-
- while( 1 ) {
-#ifdef unix
- victim = __sync_fetch_and_add(&bt->mgr->latchmgr->latchvictim, 1);
-#else
- victim = _InterlockedIncrement16 (&bt->mgr->latchmgr->latchvictim) - 1;
-#endif
- // we don't use slot zero
-
- if( victim %= bt->mgr->latchmgr->latchtotal )
- set = bt->mgr->latchsets + victim;
- else
- continue;
-
- // take control of our slot
- // from other threads
-
- if( set->pin || !bt_spinwritetry (set->busy) )
- continue;
-
- idx = set->hash;
-
- // try to get write lock on hash chain
- // skip entry if not obtained
- // or has outstanding locks
-
- if( !bt_spinwritetry (bt->mgr->latchmgr->table[idx].latch) ) {
- bt_spinreleasewrite (set->busy);
- continue;
- }
-
- if( set->pin ) {
- bt_spinreleasewrite (set->busy);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch);
- continue;
- }
-
- // unlink our available victim from its hash chain
-
- if( set->prev )
- bt->mgr->latchsets[set->prev].next = set->next;
- else
- bt->mgr->latchmgr->table[idx].slot = set->next;
-
- if( set->next )
- bt->mgr->latchsets[set->next].prev = set->prev;
-
- bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch);
-
- if( incr )
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
-
- bt_latchlink (bt, hashidx, victim, page_no);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch);
- bt_spinreleasewrite (set->busy);
- return set;
- }
-}
-
-void bt_mgrclose (BtMgr *mgr)
-{
-BtPool *pool;
-uint slot;
-
- // release mapped pages
- // note that slot zero is never used
-
- for( slot = 1; slot < mgr->poolmax; slot++ ) {
- pool = mgr->pool + slot;
- if( pool->slot )
-#ifdef unix
- munmap (pool->map, (mgr->poolmask+1) << mgr->page_bits);
-#else
- {
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
- }
-#endif
- }
-
-#ifdef unix
- close (mgr->idx);
- free (mgr->pool);
- free (mgr->hash);
- free (mgr->latch);
- free (mgr->pooladvise);
- free (mgr);
-#else
- FlushFileBuffers(mgr->idx);
- CloseHandle(mgr->idx);
- GlobalFree (mgr->pool);
- GlobalFree (mgr->hash);
- GlobalFree (mgr->latch);
- GlobalFree (mgr);
-#endif
-}
-
-// close and release memory
-
-void bt_close (BtDb *bt)
-{
-#ifdef unix
- if ( bt->mem )
- free (bt->mem);
-#else
- if ( bt->mem)
- VirtualFree (bt->mem, 0, MEM_RELEASE);
-#endif
- free (bt);
-}
-
-// open/create new btree buffer manager
-
-// call with file_name, BT_openmode, bits in page size (e.g. 16),
-// size of mapped page pool (e.g. 8192)
-
-BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolmax, uint segsize, uint hashsize)
-{
-uint lvl, attr, cacheblk, last, slot, idx;
-uint nlatchpage, latchhash;
-BtLatchMgr *latchmgr;
-off64_t size;
-uint amt[1];
-BtMgr* mgr;
-BtKey key;
-int flag;
-
-#ifndef unix
-SYSTEM_INFO sysinfo[1];
-#endif
-
- // determine sanity of page size and buffer pool
-
- if( bits > BT_maxbits )
- bits = BT_maxbits;
- else if( bits < BT_minbits )
- bits = BT_minbits;
-
- if( !poolmax )
- return NULL; // must have buffer pool
-
-#ifdef unix
- mgr = calloc (1, sizeof(BtMgr));
-
- mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
-
- if( mgr->idx == -1 )
- return free(mgr), NULL;
-
- cacheblk = 4096; // minimum mmap segment size for unix
-
-#else
- mgr = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtMgr));
- attr = FILE_ATTRIBUTE_NORMAL;
- mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
-
- if( mgr->idx == INVALID_HANDLE_VALUE )
- return GlobalFree(mgr), NULL;
-
- // normalize cacheblk to multiple of sysinfo->dwAllocationGranularity
- GetSystemInfo(sysinfo);
- cacheblk = sysinfo->dwAllocationGranularity;
-#endif
-
-#ifdef unix
- latchmgr = malloc (BT_maxpage);
- *amt = 0;
-
- // read minimum page size to get root info
-
- if( size = lseek (mgr->idx, 0L, 2) ) {
- if( pread(mgr->idx, latchmgr, BT_minpage, 0) == BT_minpage )
- bits = latchmgr->alloc->bits;
- else
- return free(mgr), free(latchmgr), NULL;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#else
- latchmgr = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
- size = GetFileSize(mgr->idx, amt);
-
- if( size || *amt ) {
- if( !ReadFile(mgr->idx, (char *)latchmgr, BT_minpage, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- bits = latchmgr->alloc->bits;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- mgr->page_size = 1 << bits;
- mgr->page_bits = bits;
-
- mgr->poolmax = poolmax;
- mgr->mode = mode;
-
- if( cacheblk < mgr->page_size )
- cacheblk = mgr->page_size;
-
- // mask for partial memmaps
-
- mgr->poolmask = (cacheblk >> bits) - 1;
-
- // see if requested size of pages per memmap is greater
-
- if( (1 << segsize) > mgr->poolmask )
- mgr->poolmask = (1 << segsize) - 1;
-
- mgr->seg_bits = 0;
-
- while( (1 << mgr->seg_bits) <= mgr->poolmask )
- mgr->seg_bits++;
-
- mgr->hashsize = hashsize;
-
-#ifdef unix
- mgr->pool = calloc (poolmax, sizeof(BtPool));
- mgr->hash = calloc (hashsize, sizeof(ushort));
- mgr->latch = calloc (hashsize, sizeof(BtSpinLatch));
- mgr->pooladvise = calloc (poolmax, (mgr->poolmask + 8) / 8);
-#else
- mgr->pool = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, poolmax * sizeof(BtPool));
- mgr->hash = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(ushort));
- mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtSpinLatch));
-#endif
-
- if( size || *amt )
- goto mgrlatch;
-
- // initialize an empty b-tree with latch page, root page, page of leaves
- // and page(s) of latches
-
- memset (latchmgr, 0, 1 << bits);
- nlatchpage = BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1;
- bt_putid(latchmgr->alloc->right, MIN_lvl+1+nlatchpage);
- latchmgr->alloc->bits = mgr->page_bits;
-
- latchmgr->nlatchpage = nlatchpage;
- latchmgr->latchtotal = nlatchpage * (mgr->page_size / sizeof(BtLatchSet));
-
- // initialize latch manager
-
- latchhash = (mgr->page_size - sizeof(BtLatchMgr)) / sizeof(BtHashEntry);
-
- // size of hash table = total number of latchsets
-
- if( latchhash > latchmgr->latchtotal )
- latchhash = latchmgr->latchtotal;
-
- latchmgr->latchhash = latchhash;
-
-#ifdef unix
- if( write (mgr->idx, latchmgr, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- memset (latchmgr, 0, 1 << bits);
- latchmgr->alloc->bits = mgr->page_bits;
-
- for( lvl=MIN_lvl; lvl--; ) {
- slotptr(latchmgr->alloc, 1)->off = mgr->page_size - 3;
- bt_putid(slotptr(latchmgr->alloc, 1)->id, lvl ? MIN_lvl - lvl + 1 : 0); // next(lower) page number
- key = keyptr(latchmgr->alloc, 1);
- key->len = 2; // create stopper key
- key->key[0] = 0xff;
- key->key[1] = 0xff;
- latchmgr->alloc->min = mgr->page_size - 3;
- latchmgr->alloc->lvl = lvl;
- latchmgr->alloc->cnt = 1;
- latchmgr->alloc->act = 1;
-#ifdef unix
- if( write (mgr->idx, latchmgr, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
- // clear out latch manager locks
- // and rest of pages to round out segment
-
- memset(latchmgr, 0, mgr->page_size);
- last = MIN_lvl + 1;
-
- while( last <= ((MIN_lvl + 1 + nlatchpage) | mgr->poolmask) ) {
-#ifdef unix
- pwrite(mgr->idx, latchmgr, mgr->page_size, last << mgr->page_bits);
-#else
- SetFilePointer (mgr->idx, last << mgr->page_bits, NULL, FILE_BEGIN);
- if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- last++;
- }
-
-mgrlatch:
-#ifdef unix
- flag = PROT_READ | PROT_WRITE;
- mgr->latchmgr = mmap (0, mgr->page_size, flag, MAP_SHARED, mgr->idx, ALLOC_page * mgr->page_size);
- if( mgr->latchmgr == MAP_FAILED )
- return bt_mgrclose (mgr), NULL;
- mgr->latchsets = (BtLatchSet *)mmap (0, mgr->latchmgr->nlatchpage * mgr->page_size, flag, MAP_SHARED, mgr->idx, LATCH_page * mgr->page_size);
- if( mgr->latchsets == MAP_FAILED )
- return bt_mgrclose (mgr), NULL;
-#else
- flag = PAGE_READWRITE;
- mgr->halloc = CreateFileMapping(mgr->idx, NULL, flag, 0, (BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1 + LATCH_page) * mgr->page_size, NULL);
- if( !mgr->halloc )
- return bt_mgrclose (mgr), NULL;
-
- flag = FILE_MAP_WRITE;
- mgr->latchmgr = MapViewOfFile(mgr->halloc, flag, 0, 0, (BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1 + LATCH_page) * mgr->page_size);
- if( !mgr->latchmgr )
- return GetLastError(), bt_mgrclose (mgr), NULL;
-
- mgr->latchsets = (void *)((char *)mgr->latchmgr + LATCH_page * mgr->page_size);
-#endif
-
-#ifdef unix
- free (latchmgr);
-#else
- VirtualFree (latchmgr, 0, MEM_RELEASE);
-#endif
- return mgr;
-}
-
-// open BTree access method
-// based on buffer manager
-
-BtDb *bt_open (BtMgr *mgr)
-{
-BtDb *bt = malloc (sizeof(*bt));
-
- memset (bt, 0, sizeof(*bt));
- bt->mgr = mgr;
-#ifdef unix
- bt->mem = malloc (3 *mgr->page_size);
-#else
- bt->mem = VirtualAlloc(NULL, 3 * mgr->page_size, MEM_COMMIT, PAGE_READWRITE);
-#endif
- bt->frame = (BtPage)bt->mem;
- bt->zero = (BtPage)(bt->mem + 1 * mgr->page_size);
- bt->cursor = (BtPage)(bt->mem + 2 * mgr->page_size);
- return bt;
-}
-
-// compare two keys, returning > 0, = 0, or < 0
-// as the comparison value
-
-int keycmp (BtKey key1, unsigned char *key2, uint len2)
-{
-uint len1 = key1->len;
-int ans;
-
- if( ans = memcmp (key1->key, key2, len1 > len2 ? len2 : len1) )
- return ans;
-
- if( len1 > len2 )
- return 1;
- if( len1 < len2 )
- return -1;
-
- return 0;
-}
-
-// Latch Manager
-
-void bt_readlock(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_rdlock (latch->lock);
-#else
- AcquireSRWLockShared (latch->srw);
-#endif
-}
-
-// wait for other read and write latches to relinquish
-
-void bt_writelock(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_wrlock (latch->lock);
-#else
- AcquireSRWLockExclusive (latch->srw);
-#endif
-}
-
-// try to obtain write lock
-
-// return 1 if obtained,
-// 0 if already write or read locked
-
-int bt_writetry(BtLatch *latch)
-{
-int result = 0;
-
-#ifdef unix
- result = !pthread_rwlock_trywrlock (latch->lock);
-#else
- result = TryAcquireSRWLockExclusive (latch->srw);
-#endif
- return result;
-}
-
-// clear write mode
-
-void bt_releasewrite(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_unlock (latch->lock);
-#else
- ReleaseSRWLockExclusive (latch->srw);
-#endif
-}
-
-// decrement reader count
-
-void bt_releaseread(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_unlock (latch->lock);
-#else
- ReleaseSRWLockShared (latch->srw);
-#endif
-}
-
-// Buffer Pool mgr
-
-// find segment in pool
-// must be called with hashslot idx locked
-// return NULL if not there
-// otherwise return node
-
-BtPool *bt_findpool(BtDb *bt, uid page_no, uint idx)
-{
-BtPool *pool;
-uint slot;
-
- // compute start of hash chain in pool
-
- if( slot = bt->mgr->hash[idx] )
- pool = bt->mgr->pool + slot;
- else
- return NULL;
-
- page_no &= ~bt->mgr->poolmask;
-
- while( pool->basepage != page_no )
- if( pool = pool->hashnext )
- continue;
- else
- return NULL;
-
- return pool;
-}
-
-// add segment to hash table
-
-void bt_linkhash(BtDb *bt, BtPool *pool, uid page_no, int idx)
-{
-BtPool *node;
-uint slot;
-
- pool->hashprev = pool->hashnext = NULL;
- pool->basepage = page_no & ~bt->mgr->poolmask;
- pool->lru = 1;
-
- if( slot = bt->mgr->hash[idx] ) {
- node = bt->mgr->pool + slot;
- pool->hashnext = node;
- node->hashprev = pool;
- }
-
- bt->mgr->hash[idx] = pool->slot;
-}
-
-// find best segment to evict from buffer pool
-
-BtPool *bt_findlru (BtDb *bt, uint hashslot)
-{
-unsigned long long int target = ~0LL;
-BtPool *pool = NULL, *node;
-
- if( !hashslot )
- return NULL;
-
- node = bt->mgr->pool + hashslot;
-
- // scan pool entries under hash table slot
-
- do {
- if( node->pin )
- continue;
- if( node->lru > target )
- continue;
- target = node->lru;
- pool = node;
- } while( node = node->hashnext );
-
- return pool;
-}
-
-// map new buffer pool segment to virtual memory
-
-BTERR bt_mapsegment(BtDb *bt, BtPool *pool, uid page_no)
-{
-off64_t off = (page_no & ~bt->mgr->poolmask) << bt->mgr->page_bits;
-off64_t limit = off + ((bt->mgr->poolmask+1) << bt->mgr->page_bits);
-int flag;
-
-#ifdef unix
- flag = PROT_READ | ( bt->mgr->mode == BT_ro ? 0 : PROT_WRITE );
- pool->map = mmap (0, (bt->mgr->poolmask+1) << bt->mgr->page_bits, flag, MAP_SHARED, bt->mgr->idx, off);
- if( pool->map == MAP_FAILED )
- return bt->err = BTERR_map;
- // clear out madvise issued bits
- memset (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8) / 8), 0, (bt->mgr->poolmask + 8)/8);
-#else
- flag = ( bt->mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
- pool->hmap = CreateFileMapping(bt->mgr->idx, NULL, flag, (DWORD)(limit >> 32), (DWORD)limit, NULL);
- if( !pool->hmap )
- return bt->err = BTERR_map;
-
- flag = ( bt->mgr->mode == BT_ro ? FILE_MAP_READ : FILE_MAP_WRITE );
- pool->map = MapViewOfFile(pool->hmap, flag, (DWORD)(off >> 32), (DWORD)off, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
- if( !pool->map )
- return bt->err = BTERR_map;
-#endif
- return bt->err = 0;
-}
-
-// find or place requested page in segment-pool
-// return pool table entry, incrementing pin
-
-BtPool *bt_pinpage(BtDb *bt, uid page_no)
-{
-BtPool *pool, *node, *next;
-uint slot, idx, victim;
-BtLatchSet *set;
-
- // lock hash table chain
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_spinreadlock (&bt->mgr->latch[idx]);
-
- // look up in hash table
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleaseread (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // upgrade to write lock
-
- bt_spinreleaseread (&bt->mgr->latch[idx]);
- bt_spinwritelock (&bt->mgr->latch[idx]);
-
- // try to find page in pool with write lock
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // allocate a new pool node
- // and add to hash table
-
-#ifdef unix
- slot = __sync_fetch_and_add(&bt->mgr->poolcnt, 1);
-#else
- slot = _InterlockedIncrement16 (&bt->mgr->poolcnt) - 1;
-#endif
-
- if( ++slot < bt->mgr->poolmax ) {
- pool = bt->mgr->pool + slot;
- pool->slot = slot;
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-
- // pool table is full
- // find best pool entry to evict
-
-#ifdef unix
- __sync_fetch_and_add(&bt->mgr->poolcnt, -1);
-#else
- _InterlockedDecrement16 (&bt->mgr->poolcnt);
-#endif
-
- while( 1 ) {
-#ifdef unix
- victim = __sync_fetch_and_add(&bt->mgr->evicted, 1);
-#else
- victim = _InterlockedIncrement16 (&bt->mgr->evicted) - 1;
-#endif
- victim %= bt->mgr->hashsize;
-
- // try to get write lock
- // skip entry if not obtained
-
- if( !bt_spinwritetry (&bt->mgr->latch[victim]) )
- continue;
-
- // if cache entry is empty
- // or no slots are unpinned
- // skip this entry
-
- if( !(pool = bt_findlru(bt, bt->mgr->hash[victim])) ) {
- bt_spinreleasewrite (&bt->mgr->latch[victim]);
- continue;
- }
-
- // unlink victim pool node from hash table
-
- if( node = pool->hashprev )
- node->hashnext = pool->hashnext;
- else if( node = pool->hashnext )
- bt->mgr->hash[victim] = node->slot;
- else
- bt->mgr->hash[victim] = 0;
-
- if( node = pool->hashnext )
- node->hashprev = pool->hashprev;
-
- bt_spinreleasewrite (&bt->mgr->latch[victim]);
-
- // remove old file mapping
-#ifdef unix
- munmap (pool->map, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
-#else
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
-#endif
- pool->map = NULL;
-
- // create new pool mapping
- // and link into hash table
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-}
-
-// place write, read, or parent lock on requested page_no.
-// pin to buffer pool and return latchset pointer
-
-BtLatchSet *bt_lockpage(BtDb *bt, uid page_no, BtLock mode, BtPage *pageptr, BtLatchSet *set)
-{
-BtPool *pool;
-uint subpage;
-BtPage page;
-
- // find/create maping in pool table
- // and pin our pool slot
-
- if( pool = bt_pinpage(bt, page_no) )
- subpage = (uint)(page_no & bt->mgr->poolmask); // page within mapping
- else
- return NULL;
-
- if( set )
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- else if( !(set = bt_bindlatch (bt, page_no, 1)) )
- return NULL;
-
- page = (BtPage)(pool->map + (subpage << bt->mgr->page_bits));
-
-#ifdef unix
- {
- uint idx = subpage / 8;
- uint bit = subpage % 8;
-
- if( mode == BtLockRead || mode == BtLockWrite )
- if( ~((bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] >> bit) & 1 ) {
- madvise (page, bt->mgr->page_size, MADV_WILLNEED);
- (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] |= 1 << bit;
- }
- }
-#endif
-
- switch( mode ) {
- case BtLockRead:
- bt_readlock (set->readwr);
- break;
- case BtLockWrite:
- bt_writelock (set->readwr);
- break;
- case BtLockAccess:
- bt_readlock (set->access);
- break;
- case BtLockDelete:
- bt_writelock (set->access);
- break;
- case BtLockParent:
- bt_writelock (set->parent);
- break;
- case BtLockPin:
- break;
- default:
- return bt->err = BTERR_lock, NULL;
- }
-
- if( pageptr )
- *pageptr = page;
-
- return set;
-}
-
-// remove write, read, or parent lock on requested page_no.
-
-BTERR bt_unlockpage(BtDb *bt, uid page_no, BtLock mode, BtLatchSet *set)
-{
-BtPool *pool;
-uint idx;
-
- // since page is pinned
- // it should still be in the buffer pool
- // and is in no danger of being a victim for reuse
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_spinreadlock (&bt->mgr->latch[idx]);
-
- if( !(pool = bt_findpool(bt, page_no, idx)) )
- return bt->err = BTERR_hash;
-
- bt_spinreleaseread (&bt->mgr->latch[idx]);
-
- switch( mode ) {
- case BtLockRead:
- bt_releaseread (set->readwr);
- break;
- case BtLockWrite:
- bt_releasewrite (set->readwr);
- break;
- case BtLockAccess:
- bt_releaseread (set->access);
- break;
- case BtLockDelete:
- bt_releasewrite (set->access);
- break;
- case BtLockParent:
- bt_releasewrite (set->parent);
- break;
- case BtLockPin:
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, -1);
- __sync_fetch_and_add (&set->pin, -1);
-#else
- _InterlockedDecrement16 (&pool->pin);
- _InterlockedDecrement16 (&set->pin);
-#endif
- return bt->err = 0;
-}
-
-// deallocate a deleted page
-// place on free chain out of allocator page
-// fence key must already be removed from parent
-
-BTERR bt_freepage(BtDb *bt, uid page_no, BtLatchSet *set)
-{
- // obtain delete lock on deleted page
-
- if( !bt_lockpage(bt, page_no, BtLockDelete, NULL, set) )
- return bt->err;
-
- // obtain write lock on deleted page
-
- if( !bt_lockpage(bt, page_no, BtLockWrite, &bt->temp, set) )
- return bt->err;
-
- // lock allocation page
-
- bt_spinwritelock(bt->mgr->latchmgr->lock);
-
- // store free chain in allocation page second right
- bt_putid(bt->temp->right, bt_getid(bt->mgr->latchmgr->alloc[1].right));
- bt_putid(bt->mgr->latchmgr->alloc[1].right, page_no);
-
- // unlock page zero
-
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
-
- // remove write lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockWrite, set) )
- return bt->err;
-
- // remove delete lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockDelete, set) )
- return bt->err;
-
- return 0;
-}
-
-// allocate a new page and write page into it
-
-uid bt_newpage(BtDb *bt, BtPage page)
-{
-BtLatchSet *set;
-uid new_page;
-BtPage pmap;
-int reuse;
-
- // lock allocation page
-
- bt_spinwritelock(bt->mgr->latchmgr->lock);
-
- // use empty chain first
- // else allocate empty page
-
- if( new_page = bt_getid(bt->mgr->latchmgr->alloc[1].right) ) {
- if( !(set = bt_lockpage (bt, new_page, BtLockWrite, &bt->temp, NULL)) )
- return 0;
- bt_putid(bt->mgr->latchmgr->alloc[1].right, bt_getid(bt->temp->right));
- if( bt_unlockpage (bt, new_page, BtLockWrite, set) )
- return 0;
- reuse = 1;
- } else {
- new_page = bt_getid(bt->mgr->latchmgr->alloc->right);
- bt_putid(bt->mgr->latchmgr->alloc->right, new_page+1);
- reuse = 0;
- }
-#ifdef unix
- if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
-
- // if writing first page of pool block, zero last page in the block
-
- if ( !reuse && bt->mgr->poolmask > 0 && (new_page & bt->mgr->poolmask) == 0 )
- {
- // use zero buffer to write zeros
- memset(bt->zero, 0, bt->mgr->page_size);
- if ( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->poolmask) << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
- }
-#else
- // bring new page into pool and copy page.
- // this will extend the file into the new pages.
-
- if( !(set = bt_lockpage(bt, new_page, BtLockWrite, &pmap, NULL)) )
- return 0;
-
- memcpy(pmap, page, bt->mgr->page_size);
-
- if( bt_unlockpage (bt, new_page, BtLockWrite, set) )
- return 0;
-#endif
- // unlock allocation latch and return new page no
-
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
- return new_page;
-}
-
-// find slot in page for given key at a given level
-
-int bt_findslot (BtDb *bt, unsigned char *key, uint len)
-{
-uint diff, higher = bt->page->cnt, low = 1, slot;
-
- // low is the lowest candidate, higher is already
- // tested as .ge. the given key, loop ends when they meet
-
- while( diff = higher - low ) {
- slot = low + ( diff >> 1 );
- if( keycmp (keyptr(bt->page, slot), key, len) < 0 )
- low = slot + 1;
- else
- higher = slot;
- }
-
- return higher;
-}
-
-// find and load page at given level for given key
-// leave page rd or wr locked as requested
-
-int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, BtLock lock)
-{
-uid page_no = ROOT_page, prevpage = 0;
-BtLatchSet *set, *prevset;
-uint drill = 0xff, slot;
-uint mode, prevmode;
-
- bt->set = NULL;
-
- // start at root of btree and drill down
-
- do {
- // determine lock mode of drill level
- mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead;
-
- bt->page_no = page_no;
-
- // obtain access lock using lock chaining with Access mode
-
- if( page_no > ROOT_page )
- if( !(bt->set = bt_lockpage(bt, page_no, BtLockAccess, NULL, NULL)) )
- return 0;
-
- // now unlock our (possibly foster) parent
-
- if( prevpage )
- if( bt_unlockpage(bt, prevpage, prevmode, prevset) )
- return 0;
- else
- prevpage = 0;
-
- // obtain read lock using lock chaining
- // and pin page contents
-
- if( !(bt->set = bt_lockpage(bt, page_no, mode, &bt->page, bt->set)) )
- return 0;
-
- if( page_no > ROOT_page )
- if( bt_unlockpage(bt, page_no, BtLockAccess, bt->set) )
- return 0;
-
- // re-read and re-lock root after determining actual level of root
-
- if( bt->page_no == ROOT_page )
- if( bt->page->lvl != drill) {
- drill = bt->page->lvl;
-
- if( lock == BtLockWrite && drill == lvl )
- if( bt_unlockpage(bt, page_no, mode, bt->set) )
- return 0;
- else
- continue;
- }
-
- prevpage = bt->page_no;
- prevset = bt->set;
- prevmode = mode;
-
- // if page is being deleted,
- // move back to preceeding page
-
- if( bt->page->kill ) {
- page_no = bt_getid (bt->page->right);
- continue;
- }
-
- // find key on page at this level
- // and descend to requested level
-
- slot = bt_findslot (bt, key, len);
-
- // is this slot a foster child?
-
- if( slot <= bt->page->cnt - bt->page->foster )
- if( drill == lvl )
- return slot;
-
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
- continue;
- else
- goto slideright;
-
- if( slot <= bt->page->cnt - bt->page->foster )
- drill--;
-
- // continue down / right using overlapping locks
- // to protect pages being killed or split.
-
- page_no = bt_getid(slotptr(bt->page, slot)->id);
- continue;
-
-slideright:
- page_no = bt_getid(bt->page->right);
-
- } while( page_no );
-
- // return error on end of chain
-
- bt->err = BTERR_struct;
- return 0; // return error
-}
-
-// find and delete key on page by marking delete flag bit
-// when page becomes empty, delete it from the btree
-
-BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl)
-{
-unsigned char leftkey[256], rightkey[256];
-BtLatchSet *rset, *set;
-uid page_no, right;
-uint slot, tod;
-BtKey ptr;
-
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // if key is found delete it, otherwise ignore request
-
- if( !keycmp (ptr, key, len) )
- if( slotptr(bt->page, slot)->dead == 0 ) {
- slotptr(bt->page,slot)->dead = 1;
- if( slot < bt->page->cnt )
- bt->page->dirty = 1;
- bt->page->act--;
- }
-
- // return if page is not empty, or it has no right sibling
-
- right = bt_getid(bt->page->right);
- page_no = bt->page_no;
- set = bt->set;
-
- if( !right || bt->page->act )
- return bt_unlockpage(bt, page_no, BtLockWrite, set);
-
- // obtain Parent lock over write lock
-
- if( !bt_lockpage(bt, page_no, BtLockParent, NULL, set) )
- return bt->err;
-
- // cache copy of key to delete
-
- ptr = keyptr(bt->page, bt->page->cnt);
- memcpy(leftkey, ptr, ptr->len + 1);
-
- // lock and map right page
-
- if( !(rset = bt_lockpage(bt, right, BtLockWrite, &bt->temp, NULL)) )
- return bt->err;
-
- // pull contents of next page into current empty page
- memcpy (bt->page, bt->temp, bt->mgr->page_size);
-
- // cache copy of key to update
- ptr = keyptr(bt->temp, bt->temp->cnt);
- memcpy(rightkey, ptr, ptr->len + 1);
-
- // Mark right page as deleted and point it to left page
- // until we can post updates at higher level.
-
- bt_putid(bt->temp->right, page_no);
- bt->temp->kill = 1;
- bt->temp->cnt = 0;
-
- if( bt_unlockpage(bt, right, BtLockWrite, rset) )
- return bt->err;
- if( bt_unlockpage(bt, page_no, BtLockWrite, set) )
- return bt->err;
-
- // delete old lower key to consolidated node
-
- if( bt_deletekey (bt, leftkey + 1, *leftkey, lvl + 1) )
- return bt->err;
-
- // redirect higher key directly to consolidated node
-
- if( slot = bt_loadpage (bt, rightkey+1, *rightkey, lvl+1, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // since key already exists, update id
-
- if( keycmp (ptr, rightkey+1, *rightkey) )
- return bt->err = BTERR_struct;
-
- slotptr(bt->page, slot)->dead = 0;
- bt_putid(slotptr(bt->page,slot)->id, page_no);
-
- if( bt_unlockpage(bt, bt->page_no, BtLockWrite, bt->set) )
- return bt->err;
-
- // obtain write lock and
- // add right block to free chain
-
- if( bt_freepage (bt, right, rset) )
- return bt->err;
-
- // remove ParentModify lock
-
- if( bt_unlockpage(bt, page_no, BtLockParent, set) )
- return bt->err;
-
- return 0;
-}
-
-// find key in leaf level and return row-id
-
-uid bt_findkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-BtKey ptr;
-uid id;
-
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- ptr = keyptr(bt->page, slot);
- else
- return 0;
-
- // if key exists, return row-id
- // otherwise return 0
-
- if( ptr->len == len && !memcmp (ptr->key, key, len) )
- id = bt_getid(slotptr(bt->page,slot)->id);
- else
- id = 0;
-
- if( bt_unlockpage (bt, bt->page_no, BtLockRead, bt->set) )
- return 0;
-
- return id;
-}
-
-// check page for space available,
-// clean if necessary and return
-// 0 - page needs splitting
-// 1 - go ahead
-
-uint bt_cleanpage(BtDb *bt, uint amt)
-{
-uint nxt = bt->mgr->page_size;
-BtPage page = bt->page;
-uint cnt = 0, idx = 0;
-uint max = page->cnt;
-BtKey key;
-
- if( page->min >= (max+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- // skip cleanup if nothing to reclaim
-
- if( !page->dirty )
- return 0;
-
- memcpy (bt->frame, page, bt->mgr->page_size);
-
- // skip page info and set rest of page to zero
-
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- page->dirty = 0;
- page->act = 0;
-
- // try cleaning up page first
-
- while( cnt++ < max ) {
- // always leave fence key and foster children in list
- if( cnt < max - page->foster && slotptr(bt->frame,cnt)->dead )
- continue;
-
- // copy key
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
-
- // copy slot
- memcpy(slotptr(page, ++idx)->id, slotptr(bt->frame, cnt)->id, BtId);
- if( !(slotptr(page, idx)->dead = slotptr(bt->frame, cnt)->dead) )
- page->act++;
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // see if page has enough space now, or does it need splitting?
-
- if( page->min >= (idx+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- return 0;
-}
-
-// add key to current page
-// page must already be writelocked
-
-void bt_addkeytopage (BtDb *bt, uint slot, unsigned char *key, uint len, uid id, uint tod)
-{
-BtPage page = bt->page;
-uint idx;
-
- // calculate next available slot and copy key into page
-
- page->min -= len + 1;
- ((unsigned char *)page)[page->min] = len;
- memcpy ((unsigned char *)page + page->min +1, key, len );
-
- for( idx = slot; idx < page->cnt; idx++ )
- if( slotptr(page, idx)->dead )
- break;
-
- // now insert key into array before slot
- // preserving the fence slot
-
- if( idx == page->cnt )
- idx++, page->cnt++;
-
- page->act++;
-
- while( idx > slot )
- *slotptr(page, idx) = *slotptr(page, idx -1), idx--;
-
- bt_putid(slotptr(page,slot)->id, id);
- slotptr(page, slot)->off = page->min;
- slotptr(page, slot)->tod = tod;
- slotptr(page, slot)->dead = 0;
-}
-
-// split the root and raise the height of the btree
-// call with current page locked and page no of foster child
-// return with current page (root) unlocked
-
-BTERR bt_splitroot(BtDb *bt, uid right)
-{
-uint nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-BtPage root = bt->page;
-uid new_page;
-BtKey key;
-
- // Obtain an empty page to use, and copy the left page
- // contents into it from the root. Strip foster child key.
- // (it's the stopper key)
-
- root->act--;
- root->cnt--;
- root->foster--;
-
- // Save left fence key.
-
- key = keyptr(root, root->cnt);
- memcpy (fencekey, key, key->len + 1);
-
- // copy the lower keys into a new left page
-
- if( !(new_page = bt_newpage(bt, root)) )
- return bt->err;
-
- // preserve the page info at the bottom
- // and set rest of the root to zero
-
- memset (root+1, 0, bt->mgr->page_size - sizeof(*root));
-
- // insert left fence key on empty newroot page
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 1)->id, new_page);
- slotptr(root, 1)->off = nxt;
-
- // insert stopper key on newroot page
- // and increase the root height
-
- nxt -= 3;
- fencekey[0] = 2;
- fencekey[1] = 0xff;
- fencekey[2] = 0xff;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 2)->id, right);
- slotptr(root, 2)->off = nxt;
-
- bt_putid(root->right, 0);
- root->min = nxt; // reset lowest used offset and key count
- root->cnt = 2;
- root->act = 2;
- root->lvl++;
-
- // release root (bt->page)
-
- return bt_unlockpage(bt, ROOT_page, BtLockWrite, bt->set);
-}
-
-// split already locked full node
-// in current page variables
-// return unlocked.
-
-BTERR bt_splitpage (BtDb *bt)
-{
-uint slot, cnt, idx, max, nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-uid page_no = bt->page_no;
-BtLatchSet *set = bt->set;
-BtPage page = bt->page;
-uint tod = time(NULL);
-uint lvl = page->lvl;
-uid new_page, right;
-BtKey key;
-
- // initialize frame buffer
-
- memset (bt->frame, 0, bt->mgr->page_size);
- max = page->cnt - page->foster;
- tod = (uint)time(NULL);
- cnt = max / 2;
- idx = 0;
-
- // split higher half of keys to bt->frame
- // leaving foster children in the left node.
-
- while( cnt++ < max ) {
- key = keyptr(page, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)bt->frame + nxt, key, key->len + 1);
- memcpy(slotptr(bt->frame,++idx)->id, slotptr(page,cnt)->id, BtId);
- slotptr(bt->frame, idx)->tod = slotptr(page, cnt)->tod;
- slotptr(bt->frame, idx)->off = nxt;
- bt->frame->act++;
- }
-
- // transfer right link node
-
- if( page_no > ROOT_page ) {
- right = bt_getid (page->right);
- bt_putid(bt->frame->right, right);
- }
-
- bt->frame->bits = bt->mgr->page_bits;
- bt->frame->min = nxt;
- bt->frame->cnt = idx;
- bt->frame->lvl = lvl;
-
- // get new free page and write frame to it.
-
- if( !(new_page = bt_newpage(bt, bt->frame)) )
- return bt->err;
-
- // remember fence key for new page to add
- // as foster child
-
- key = keyptr(bt->frame, idx);
- memcpy (fencekey, key, key->len + 1);
-
- // update lower keys and foster children to continue in old page
-
- memcpy (bt->frame, page, bt->mgr->page_size);
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- nxt = bt->mgr->page_size;
- page->act = 0;
- cnt = 0;
- idx = 0;
-
- // assemble page of smaller keys
- // to remain in the old page
-
- while( cnt++ < max / 2 ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- // insert new foster child at beginning of the current foster children
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)page + nxt, fencekey, *fencekey + 1);
- bt_putid (slotptr(page,++idx)->id, new_page);
- slotptr(page, idx)->tod = tod;
- slotptr(page, idx)->off = nxt;
- page->foster++;
- page->act++;
-
- // continue with old foster child keys if any
-
- cnt = bt->frame->cnt - bt->frame->foster;
-
- while( cnt++ < bt->frame->cnt ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // link new right page
-
- bt_putid (page->right, new_page);
-
- // if current page is the root page, split it
-
- if( page_no == ROOT_page )
- return bt_splitroot (bt, new_page);
-
- // keep our latch set
- // release wr lock on our page
-
- if( !bt_lockpage (bt, page_no, BtLockPin, NULL, set) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockWrite, set) )
- return bt->err;
-
- // obtain ParentModification lock for current page
- // to fix fence key and highest foster child on page
-
- if( !bt_lockpage (bt, page_no, BtLockParent, NULL, set) )
- return bt->err;
-
- // get our highest foster child key to find in parent node
-
- if( !bt_lockpage (bt, page_no, BtLockRead, &page, set) )
- return bt->err;
-
- key = keyptr(page, page->cnt);
- memcpy (fencekey, key, key->len+1);
-
- if( bt_unlockpage (bt, page_no, BtLockRead, set) )
- return bt->err;
-
- // update our parent
-try_again:
-
- do {
- slot = bt_loadpage (bt, fencekey + 1, *fencekey, lvl + 1, BtLockWrite);
-
- if( !slot )
- return bt->err;
-
- // check if parent page has enough space for any possible key
-
- if( bt_cleanpage (bt, 256) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- } while( 1 );
-
- // see if we are still a foster child from another node
-
- if( bt_getid (slotptr(bt->page, slot)->id) != page_no ) {
- if( bt_unlockpage (bt, bt->page_no, BtLockWrite, bt->set) )
- return bt->err;
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- goto try_again;
- }
-
- // wait until readers from parent get their locks
- // on our page
-
- if( !bt_lockpage (bt, page_no, BtLockDelete, NULL, set) )
- return bt->err;
-
- // lock our page for writing
-
- if( !bt_lockpage (bt, page_no, BtLockWrite, &page, set) )
- return bt->err;
-
- // switch parent fence key to foster child
-
- if( slotptr(page, page->cnt)->dead )
- slotptr(bt->page, slot)->dead = 1;
- else
- bt_putid (slotptr(bt->page, slot)->id, bt_getid(slotptr(page, page->cnt)->id));
-
- // remove highest foster child from our page
-
- page->cnt--;
- page->act--;
- page->foster--;
- page->dirty = 1;
- key = keyptr(page, page->cnt);
-
- // add our new fence key for foster child to our parent
-
- bt_addkeytopage (bt, slot, key->key, key->len, page_no, tod);
-
- if( bt_unlockpage (bt, bt->page_no, BtLockWrite, bt->set) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockDelete, set) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockWrite, set) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockParent, set) )
- return bt->err;
-
- // release extra latch pin
-
- return bt_unlockpage (bt, page_no, BtLockPin, set);
-}
-
-// Insert new key into the btree at leaf level.
-
-BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod)
-{
-uint slot, idx;
-BtPage page;
-BtKey ptr;
-
- while( 1 ) {
- if( slot = bt_loadpage (bt, key, len, 0, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- {
- if ( !bt->err )
- bt->err = BTERR_ovflw;
- return bt->err;
- }
-
- // if key already exists, update id and return
-
- page = bt->page;
-
- if( !keycmp (ptr, key, len) ) {
- slotptr(page, slot)->dead = 0;
- slotptr(page, slot)->tod = tod;
- bt_putid(slotptr(page,slot)->id, id);
- return bt_unlockpage(bt, bt->page_no, BtLockWrite, bt->set);
- }
-
- // check if page has enough space
-
- if( bt_cleanpage (bt, len) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- }
-
- bt_addkeytopage (bt, slot, key, len, id, tod);
-
- return bt_unlockpage (bt, bt->page_no, BtLockWrite, bt->set);
-}
-
-// cache page of keys into cursor and return starting slot for given key
-
-uint bt_startkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-
- // cache page for retrieval
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- memcpy (bt->cursor, bt->page, bt->mgr->page_size);
- bt->cursor_page = bt->page_no;
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead, bt->set) )
- return 0;
-
- return slot;
-}
-
-// return next slot for cursor page
-// or slide cursor right into next page
-
-uint bt_nextkey (BtDb *bt, uint slot)
-{
-BtLatchSet *rset;
-BtPage page;
-uid right;
-
- do {
- right = bt_getid(bt->cursor->right);
- while( slot++ < bt->cursor->cnt - bt->cursor->foster )
- if( slotptr(bt->cursor,slot)->dead )
- continue;
- else if( right || (slot < bt->cursor->cnt - bt->cursor->foster) )
- return slot;
- else
- break;
-
- if( !right )
- break;
-
- bt->cursor_page = right;
-
- if( !(bt->set = bt_lockpage(bt, right, BtLockRead, &page, NULL)) )
- return 0;
-
- memcpy (bt->cursor, page, bt->mgr->page_size);
-
- if ( bt_unlockpage(bt, right, BtLockRead, bt->set) )
- return 0;
-
- slot = 0;
- } while( 1 );
-
- return bt->err = 0;
-}
-
-BtKey bt_key(BtDb *bt, uint slot)
-{
- return keyptr(bt->cursor, slot);
-}
-
-uid bt_uid(BtDb *bt, uint slot)
-{
- return bt_getid(slotptr(bt->cursor,slot)->id);
-}
-
-uint bt_tod(BtDb *bt, uint slot)
-{
- return slotptr(bt->cursor,slot)->tod;
-}
-
-
-#ifdef STANDALONE
-
-typedef struct {
- char type, idx;
- char *infile;
- BtMgr *mgr;
- int num;
-} ThreadArg;
-
-// standalone program to index file of keys
-// then list them onto std-out
-
-#ifdef unix
-void *index_file (void *arg)
-#else
-uint __stdcall index_file (void *arg)
-#endif
-{
-int line = 0, found = 0, cnt = 0;
-uid next, page_no = LEAF_page; // start on first page of leaves
-unsigned char key[256];
-ThreadArg *args = arg;
-int ch, len = 0, slot;
-time_t tod[1];
-BtPage page;
-BtKey ptr;
-BtDb *bt;
-FILE *in;
-
- bt = bt_open (args->mgr);
- time (tod);
-
- switch(args->type | 0x20)
- {
- case 'w':
- fprintf(stderr, "started indexing for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
-
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_insertkey (bt, key, len, line, *tod) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys\n", args->infile, line);
- break;
-
- case 'd':
- fprintf(stderr, "started deleting keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_deletekey (bt, key, len, 0) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for keys, %d \n", args->infile, line);
- break;
-
- case 'f':
- fprintf(stderr, "started finding keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_findkey (bt, key, len) )
- found++;
- else if( bt->err )
- fprintf(stderr, "Error %d Syserr %d Line: %d\n", bt->err, errno, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys, found %d\n", args->infile, line, found);
- break;
-
- case 's':
- len = key[0] = 0;
-
- fprintf(stderr, "started reading\n");
-
- if( slot = bt_startkey (bt, key, len) )
- slot--;
- else
- fprintf(stderr, "Error %d in StartKey. Syserror: %d\n", bt->err, errno), exit(0);
-
- while( slot = bt_nextkey (bt, slot) ) {
- ptr = bt_key(bt, slot);
- fwrite (ptr->key, ptr->len, 1, stdout);
- fputc ('\n', stdout);
- }
-
- break;
-
- case 'c':
- fprintf(stderr, "started reading\n");
-
- do {
- bt->set = bt_lockpage (bt, page_no, BtLockRead, &page, NULL);
- cnt += page->act;
- next = bt_getid (page->right);
- bt_unlockpage (bt, page_no, BtLockRead, bt->set);
- } while( page_no = next );
-
- cnt--; // remove stopper key
- fprintf(stderr, " Total keys read %d\n", cnt);
- break;
- }
-
- bt_close (bt);
-#ifdef unix
- return NULL;
-#else
- return 0;
-#endif
-}
-
-typedef struct timeval timer;
-
-int main (int argc, char **argv)
-{
-int idx, cnt, len, slot, err;
-int segsize, bits = 16;
-#ifdef unix
-pthread_t *threads;
-timer start, stop;
-#else
-time_t start[1], stop[1];
-HANDLE *threads;
-#endif
-double real_time;
-ThreadArg *args;
-uint poolsize = 0;
-int num = 0;
-char key[1];
-BtMgr *mgr;
-BtKey ptr;
-BtDb *bt;
-
- if( argc < 3 ) {
- fprintf (stderr, "Usage: %s idx_file Read/Write/Scan/Delete/Find [page_bits mapped_segments seg_bits line_numbers src_file1 src_file2 ... ]\n", argv[0]);
- fprintf (stderr, " where page_bits is the page size in bits\n");
- fprintf (stderr, " mapped_segments is the number of mmap segments in buffer pool\n");
- fprintf (stderr, " seg_bits is the size of individual segments in buffer pool in pages in bits\n");
- fprintf (stderr, " line_numbers = 1 to append line numbers to keys\n");
- fprintf (stderr, " src_file1 thru src_filen are files of keys separated by newline\n");
- exit(0);
- }
-
-#ifdef unix
- gettimeofday(&start, NULL);
-#else
- time(start);
-#endif
-
- if( argc > 3 )
- bits = atoi(argv[3]);
-
- if( argc > 4 )
- poolsize = atoi(argv[4]);
-
- if( !poolsize )
- fprintf (stderr, "Warning: no mapped_pool\n");
-
- if( poolsize > 65535 )
- fprintf (stderr, "Warning: mapped_pool > 65535 segments\n");
-
- if( argc > 5 )
- segsize = atoi(argv[5]);
- else
- segsize = 4; // 16 pages per mmap segment
-
- if( argc > 6 )
- num = atoi(argv[6]);
-
- cnt = argc - 7;
-#ifdef unix
- threads = malloc (cnt * sizeof(pthread_t));
-#else
- threads = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, cnt * sizeof(HANDLE));
-#endif
- args = malloc (cnt * sizeof(ThreadArg));
-
- mgr = bt_mgr ((argv[1]), BT_rw, bits, poolsize, segsize, poolsize / 8);
-
- if( !mgr ) {
- fprintf(stderr, "Index Open Error %s\n", argv[1]);
- exit (1);
- }
-
- // fire off threads
-
- for( idx = 0; idx < cnt; idx++ ) {
- args[idx].infile = argv[idx + 7];
- args[idx].type = argv[2][0];
- args[idx].mgr = mgr;
- args[idx].num = num;
- args[idx].idx = idx;
-#ifdef unix
- if( err = pthread_create (threads + idx, NULL, index_file, args + idx) )
- fprintf(stderr, "Error creating thread %d\n", err);
-#else
- threads[idx] = (HANDLE)_beginthreadex(NULL, 65536, index_file, args + idx, 0, NULL);
-#endif
- }
-
- // wait for termination
-
-#ifdef unix
- for( idx = 0; idx < cnt; idx++ )
- pthread_join (threads[idx], NULL);
- gettimeofday(&stop, NULL);
- real_time = 1000.0 * ( stop.tv_sec - start.tv_sec ) + 0.001 * (stop.tv_usec - start.tv_usec );
-#else
- WaitForMultipleObjects (cnt, threads, TRUE, INFINITE);
-
- for( idx = 0; idx < cnt; idx++ )
- CloseHandle(threads[idx]);
-
- time (stop);
- real_time = 1000 * (*stop - *start);
-#endif
- fprintf(stderr, " Time to complete: %.2f seconds\n", real_time/1000);
- bt_mgrclose (mgr);
-}
-
-#endif //STANDALONE
+++ /dev/null
-// foster btree version e2
-// 18 JAN 2014
-
-// author: karl malbrain, malbrain@cal.berkeley.edu
-
-/*
-This work, including the source code, documentation
-and related data, is placed into the public domain.
-
-The orginal author is Karl Malbrain.
-
-THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
-OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
-MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
-ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
-RESULTING FROM THE USE, MODIFICATION, OR
-REDISTRIBUTION OF THIS SOFTWARE.
-*/
-
-// Please see the project home page for documentation
-// code.google.com/p/high-concurrency-btree
-
-#define _FILE_OFFSET_BITS 64
-#define _LARGEFILE64_SOURCE
-
-#ifdef linux
-#define _GNU_SOURCE
-#endif
-
-#ifdef unix
-#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <sys/time.h>
-#include <sys/mman.h>
-#include <errno.h>
-#include <pthread.h>
-#else
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <fcntl.h>
-#include <process.h>
-#include <intrin.h>
-#endif
-
-#include <memory.h>
-#include <string.h>
-
-typedef unsigned long long uid;
-
-#ifndef unix
-typedef unsigned long long off64_t;
-typedef unsigned short ushort;
-typedef unsigned int uint;
-#endif
-
-#define BT_ro 0x6f72 // ro
-#define BT_rw 0x7772 // rw
-
-#define BT_latchtable 128 // number of latch manager slots
-
-#define BT_maxbits 24 // maximum page size in bits
-#define BT_minbits 9 // minimum page size in bits
-#define BT_minpage (1 << BT_minbits) // minimum page size
-#define BT_maxpage (1 << BT_maxbits) // maximum page size
-
-/*
-There are five lock types for each node in three independent sets:
-1. (set 1) AccessIntent: Sharable. Going to Read the node. Incompatible with NodeDelete.
-2. (set 1) NodeDelete: Exclusive. About to release the node. Incompatible with AccessIntent.
-3. (set 2) ReadLock: Sharable. Read the node. Incompatible with WriteLock.
-4. (set 2) WriteLock: Exclusive. Modify the node. Incompatible with ReadLock and other WriteLocks.
-5. (set 3) ParentLock: Exclusive. Have parent adopt/delete maximum foster child from the node.
-*/
-
-typedef enum{
- BtLockAccess,
- BtLockDelete,
- BtLockRead,
- BtLockWrite,
- BtLockParent
-}BtLock;
-
-// Define the length of the page and key pointers
-
-#define BtId 6
-
-// Page key slot definition.
-
-// If BT_maxbits is 15 or less, you can save 4 bytes
-// for each key stored by making the first two uints
-// into ushorts. You can also save 4 bytes by removing
-// the tod field from the key.
-
-// Keys are marked dead, but remain on the page until
-// cleanup is called. The fence key (highest key) for
-// the page is always present, even after cleanup.
-
-typedef struct {
- uint off:BT_maxbits; // page offset for key start
- uint dead:1; // set for deleted key
- uint tod; // time-stamp for key
- unsigned char id[BtId]; // id associated with key
-} BtSlot;
-
-// The key structure occupies space at the upper end of
-// each page. It's a length byte followed by the value
-// bytes.
-
-typedef struct {
- unsigned char len;
- unsigned char key[1];
-} *BtKey;
-
-// The first part of an index page.
-// It is immediately followed
-// by the BtSlot array of keys.
-
-typedef struct Page {
- volatile uint cnt; // count of keys in page
- volatile uint act; // count of active keys
- volatile uint min; // next key offset
- volatile uint foster; // count of foster children
- unsigned char bits; // page size in bits
- unsigned char lvl:7; // level of page
- unsigned char dirty:1; // page needs to be cleaned
- unsigned char right[BtId]; // page number to right
-} *BtPage;
-
-// mode & definition for hash latch implementation
-
-enum {
- Mutex = 1,
- Write = 2,
- Pending = 4,
- Share = 8
-} LockMode;
-
-// mutex locks the other fields
-// exclusive is set for write access
-// share is count of read accessors
-
-typedef struct {
- volatile ushort mutex:1;
- volatile ushort exclusive:1;
- volatile ushort pending:1;
- volatile ushort share:13;
-} BtSpinLatch;
-
-// hash table entries
-
-typedef struct {
- BtSpinLatch latch[1];
- volatile ushort slot; // Latch table entry at head of chain
-} BtHashEntry;
-
-// latch manager table structure
-
-typedef struct {
-#ifdef unix
- pthread_rwlock_t lock[1];
-#else
- SRWLOCK srw[1];
-#endif
-} BtLatch;
-
-typedef struct {
- BtLatch readwr[1]; // read/write page lock
- BtLatch access[1]; // Access Intent/Page delete
- BtLatch parent[1]; // adoption of foster children
- BtSpinLatch busy[1]; // slot is being moved between chains
- volatile ushort next; // next entry in hash table chain
- volatile ushort prev; // prev entry in hash table chain
- volatile ushort pin; // number of outstanding locks
- volatile ushort hash; // hash slot entry is under
- volatile uid page_no; // latch set page number
-} BtLatchSet;
-
-// The memory mapping pool table buffer manager entry
-
-typedef struct {
- unsigned long long int lru; // number of times accessed
- uid basepage; // mapped base page number
- char *map; // mapped memory pointer
- ushort pin; // mapped page pin counter
- ushort slot; // slot index in this array
- void *hashprev; // previous pool entry for the same hash idx
- void *hashnext; // next pool entry for the same hash idx
-#ifndef unix
- HANDLE hmap; // Windows memory mapping handle
-#endif
-} BtPool;
-
-// structure for latch manager on ALLOC_page
-
-typedef struct {
- struct Page alloc[2]; // next & free page_nos in right ptr
- BtSpinLatch lock[1]; // allocation area lite latch
- ushort latchdeployed; // highest number of latch entries deployed
- ushort nlatchpage; // number of latch pages at BT_latch
- ushort latchtotal; // number of page latch entries
- ushort latchhash; // number of latch hash table slots
- ushort latchvictim; // next latch entry to examine
- BtHashEntry table[0]; // the hash table
-} BtLatchMgr;
-
-// The object structure for Btree access
-
-typedef struct {
- uint page_size; // page size
- uint page_bits; // page size in bits
- uint seg_bits; // seg size in pages in bits
- uint mode; // read-write mode
-#ifdef unix
- int idx;
- char *pooladvise; // bit maps for pool page advisements
-#else
- HANDLE idx;
-#endif
- ushort poolcnt; // highest page pool node in use
- ushort poolmax; // highest page pool node allocated
- ushort poolmask; // total number of pages in mmap segment - 1
- ushort hashsize; // size of Hash Table for pool entries
- ushort evicted; // last evicted hash table slot
- ushort *hash; // hash table of pool entries
- BtPool *pool; // memory pool page segments
- BtSpinLatch *latch; // latches for pool hash slots
- BtLatchMgr *latchmgr; // mapped latch page from allocation page
- BtLatchSet *latchsets; // mapped latch set from latch pages
-#ifndef unix
- HANDLE halloc; // allocation and latch table handle
-#endif
-} BtMgr;
-
-typedef struct {
- BtMgr *mgr; // buffer manager for thread
- BtPage cursor; // cached frame for start/next (never mapped)
- BtPage frame; // spare frame for the page split (never mapped)
- BtPage zero; // page frame for zeroes at end of file
- BtPage page; // current page
- uid page_no; // current page number
- uid cursor_page; // current cursor page number
- BtLatchSet *set; // current page latch set
- BtPool *pool; // current page pool
- unsigned char *mem; // frame, cursor, page memory buffer
- int found; // last delete was found
- int err; // last error
-} BtDb;
-
-typedef enum {
- BTERR_ok = 0,
- BTERR_struct,
- BTERR_ovflw,
- BTERR_lock,
- BTERR_map,
- BTERR_wrt,
- BTERR_hash,
- BTERR_latch
-} BTERR;
-
-// B-Tree functions
-extern void bt_close (BtDb *bt);
-extern BtDb *bt_open (BtMgr *mgr);
-extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod, uint lvl);
-extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len);
-extern uid bt_findkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_nextkey (BtDb *bt, uint slot);
-
-// manager functions
-extern BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolsize, uint segsize, uint hashsize);
-void bt_mgrclose (BtMgr *mgr);
-
-// Helper functions to return cursor slot values
-
-extern BtKey bt_key (BtDb *bt, uint slot);
-extern uid bt_uid (BtDb *bt, uint slot);
-extern uint bt_tod (BtDb *bt, uint slot);
-
-// BTree page number constants
-#define ALLOC_page 0 // allocation & lock manager hash table
-#define ROOT_page 1 // root of the btree
-#define LEAF_page 2 // first page of leaves
-#define LATCH_page 3 // pages for lock manager
-
-// Number of levels to create in a new BTree
-
-#define MIN_lvl 2
-
-// The page is allocated from low and hi ends.
-// The key offsets and row-id's are allocated
-// from the bottom, while the text of the key
-// is allocated from the top. When the two
-// areas meet, the page is split into two.
-
-// A key consists of a length byte, two bytes of
-// index number (0 - 65534), and up to 253 bytes
-// of key value. Duplicate keys are discarded.
-// Associated with each key is a 48 bit row-id.
-
-// The b-tree root is always located at page 1.
-// The first leaf page of level zero is always
-// located on page 2.
-
-// When to root page fills, it is split in two and
-// the tree height is raised by a new root at page
-// one with two keys.
-
-// Deleted keys are marked with a dead bit until
-// page cleanup The fence key for a node is always
-// present, even after deletion and cleanup.
-
-// Groups of pages called segments from the btree are
-// cached with memory mapping. A hash table is used to keep
-// track of the cached segments. This behaviour is controlled
-// by the cache block size parameter to bt_open.
-
-// To achieve maximum concurrency one page is locked at a time
-// as the tree is traversed to find leaf key in question.
-
-// An adoption traversal leaves the parent node locked as the
-// tree is traversed to the level in quesiton.
-
-// Page 0 is dedicated to lock for new page extensions,
-// and chains empty pages together for reuse.
-
-// Empty pages are chained together through the ALLOC page and reused.
-
-// Access macros to address slot and key values from the page
-
-#define slotptr(page, slot) (((BtSlot *)(page+1)) + (slot-1))
-#define keyptr(page, slot) ((BtKey)((unsigned char*)(page) + slotptr(page, slot)->off))
-
-void bt_putid(unsigned char *dest, uid id)
-{
-int i = BtId;
-
- while( i-- )
- dest[i] = (unsigned char)id, id >>= 8;
-}
-
-uid bt_getid(unsigned char *src)
-{
-uid id = 0;
-int i;
-
- for( i = 0; i < BtId; i++ )
- id <<= 8, id |= *src++;
-
- return id;
-}
-
-// wait until write lock mode is clear
-// and add 1 to the share count
-
-void bt_spinreadlock(BtSpinLatch *latch)
-{
-ushort prev;
-
- do {
-#ifdef unix
- while( __sync_fetch_and_or((ushort *)latch, Mutex) & Mutex )
- sched_yield();
-#else
- while( _InterlockedOr16((ushort *)latch, Mutex) & Mutex )
- SwitchToThread();
-#endif
-
- // see if exclusive request is granted or pending
-
- if( prev = !(latch->exclusive | latch->pending) )
-#ifdef unix
- __sync_fetch_and_add((ushort *)latch, Share);
-#else
- _InterlockedExchangeAdd16 ((ushort *)latch, Share);
-#endif
-
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
-#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
-#endif
- if( prev )
- return;
-#ifdef unix
- } while( sched_yield(), 1 );
-#else
- } while( SwitchToThread(), 1 );
-#endif
-}
-
-// wait for other read and write latches to relinquish
-
-void bt_spinwritelock(BtSpinLatch *latch)
-{
- do {
-#ifdef unix
- while( __sync_fetch_and_or((ushort *)latch, Mutex | Pending) & Mutex )
- sched_yield();
-#else
- while( _InterlockedOr16((ushort *)latch, Mutex | Pending) & Mutex )
- SwitchToThread();
-#endif
- if( !(latch->share | latch->exclusive) ) {
-#ifdef unix
- __sync_fetch_and_or((ushort *)latch, Write);
- __sync_fetch_and_and ((ushort *)latch, ~(Mutex | Pending));
-#else
- _InterlockedOr16((ushort *)latch, Write);
- _InterlockedAnd16((ushort *)latch, ~(Mutex | Pending));
-#endif
- return;
- }
-
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
-#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
-#endif
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- } while( 1 );
-}
-
-// try to obtain write lock
-
-// return 1 if obtained,
-// 0 otherwise
-
-int bt_spinwritetry(BtSpinLatch *latch)
-{
-ushort prev;
-
-#ifdef unix
- if( prev = __sync_fetch_and_or((ushort *)latch, Mutex), prev & Mutex )
- return 0;
-#else
- if( prev = _InterlockedOr16((ushort *)latch, Mutex), prev & Mutex )
- return 0;
-#endif
- // take write access if all bits are clear
-
- if( !prev )
-#ifdef unix
- __sync_fetch_and_or ((ushort *)latch, Write);
-#else
- _InterlockedOr16((ushort *)latch, Write);
-#endif
-
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
-#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
-#endif
- return !prev;
-}
-
-// clear write mode
-
-void bt_spinreleasewrite(BtSpinLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Write);
-#else
- _InterlockedAnd16((ushort *)latch, ~Write);
-#endif
-}
-
-// decrement reader count
-
-void bt_spinreleaseread(BtSpinLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_add((ushort *)latch, -Share);
-#else
- _InterlockedExchangeAdd16 ((ushort *)latch, -Share);
-#endif
-}
-
-void bt_initlockset (BtLatchSet *set, int reuse)
-{
-#ifdef unix
-pthread_rwlockattr_t rwattr[1];
-
- if( reuse ) {
- pthread_rwlock_destroy (set->readwr->lock);
- pthread_rwlock_destroy (set->access->lock);
- pthread_rwlock_destroy (set->parent->lock);
- }
-
- pthread_rwlockattr_init (rwattr);
- pthread_rwlockattr_setkind_np (rwattr, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
- pthread_rwlockattr_setpshared (rwattr, PTHREAD_PROCESS_SHARED);
-
- pthread_rwlock_init (set->readwr->lock, rwattr);
- pthread_rwlock_init (set->access->lock, rwattr);
- pthread_rwlock_init (set->parent->lock, rwattr);
- pthread_rwlockattr_destroy (rwattr);
-#else
- InitializeSRWLock (set->readwr->srw);
- InitializeSRWLock (set->access->srw);
- InitializeSRWLock (set->parent->srw);
-#endif
-}
-
-// link latch table entry into latch hash table
-
-void bt_latchlink (BtDb *bt, ushort hashidx, ushort victim, uid page_no)
-{
-BtLatchSet *set = bt->mgr->latchsets + victim;
-
- if( set->next = bt->mgr->latchmgr->table[hashidx].slot )
- bt->mgr->latchsets[set->next].prev = victim;
-
- bt->mgr->latchmgr->table[hashidx].slot = victim;
- set->page_no = page_no;
- set->hash = hashidx;
- set->prev = 0;
-}
-
-void bt_unpinlatch (BtLatchSet *set)
-{
-#ifdef unix
- __sync_fetch_and_add(&set->pin, -1);
-#else
- _InterlockedDecrement16 (&set->pin);
-#endif
-}
-
-// find existing latchset or inspire new one
-// return with latchset pinned
-
-BtLatchSet *bt_pinlatch (BtDb *bt, uid page_no)
-{
-ushort hashidx = page_no % bt->mgr->latchmgr->latchhash;
-ushort slot, avail = 0, victim, idx;
-BtLatchSet *set;
-
- // obtain read lock on hash table entry
-
- bt_spinreadlock(bt->mgr->latchmgr->table[hashidx].latch);
-
- if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
- {
- set = bt->mgr->latchsets + slot;
- if( page_no == set->page_no )
- break;
- } while( slot = set->next );
-
- if( slot ) {
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- }
-
- bt_spinreleaseread (bt->mgr->latchmgr->table[hashidx].latch);
-
- if( slot )
- return set;
-
- // try again, this time with write lock
-
- bt_spinwritelock(bt->mgr->latchmgr->table[hashidx].latch);
-
- if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
- {
- set = bt->mgr->latchsets + slot;
- if( page_no == set->page_no )
- break;
- if( !set->pin && !avail )
- avail = slot;
- } while( slot = set->next );
-
- // found our entry, or take over an unpinned one
-
- if( slot || (slot = avail) ) {
- set = bt->mgr->latchsets + slot;
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- set->page_no = page_no;
- bt_spinreleasewrite(bt->mgr->latchmgr->table[hashidx].latch);
- return set;
- }
-
- // see if there are any unused entries
-#ifdef unix
- victim = __sync_fetch_and_add (&bt->mgr->latchmgr->latchdeployed, 1) + 1;
-#else
- victim = _InterlockedIncrement16 (&bt->mgr->latchmgr->latchdeployed);
-#endif
-
- if( victim < bt->mgr->latchmgr->latchtotal ) {
- set = bt->mgr->latchsets + victim;
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- bt_initlockset (set, 0);
- bt_latchlink (bt, hashidx, victim, page_no);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch);
- return set;
- }
-
-#ifdef unix
- victim = __sync_fetch_and_add (&bt->mgr->latchmgr->latchdeployed, -1);
-#else
- victim = _InterlockedDecrement16 (&bt->mgr->latchmgr->latchdeployed);
-#endif
- // find and reuse previous lock entry
-
- while( 1 ) {
-#ifdef unix
- victim = __sync_fetch_and_add(&bt->mgr->latchmgr->latchvictim, 1);
-#else
- victim = _InterlockedIncrement16 (&bt->mgr->latchmgr->latchvictim) - 1;
-#endif
- // we don't use slot zero
-
- if( victim %= bt->mgr->latchmgr->latchtotal )
- set = bt->mgr->latchsets + victim;
- else
- continue;
-
- // take control of our slot
- // from other threads
-
- if( set->pin || !bt_spinwritetry (set->busy) )
- continue;
-
- idx = set->hash;
-
- // try to get write lock on hash chain
- // skip entry if not obtained
- // or has outstanding locks
-
- if( !bt_spinwritetry (bt->mgr->latchmgr->table[idx].latch) ) {
- bt_spinreleasewrite (set->busy);
- continue;
- }
-
- if( set->pin ) {
- bt_spinreleasewrite (set->busy);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch);
- continue;
- }
-
- // unlink our available victim from its hash chain
-
- if( set->prev )
- bt->mgr->latchsets[set->prev].next = set->next;
- else
- bt->mgr->latchmgr->table[idx].slot = set->next;
-
- if( set->next )
- bt->mgr->latchsets[set->next].prev = set->prev;
-
- bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch);
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- bt_initlockset (set, 1);
- bt_latchlink (bt, hashidx, victim, page_no);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch);
- bt_spinreleasewrite (set->busy);
- return set;
- }
-}
-
-void bt_mgrclose (BtMgr *mgr)
-{
-BtPool *pool;
-uint slot;
-
- // release mapped pages
- // note that slot zero is never used
-
- for( slot = 1; slot < mgr->poolmax; slot++ ) {
- pool = mgr->pool + slot;
- if( pool->slot )
-#ifdef unix
- munmap (pool->map, (mgr->poolmask+1) << mgr->page_bits);
-#else
- {
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
- }
-#endif
- }
-
-#ifdef unix
- munmap (mgr->latchsets, mgr->latchmgr->nlatchpage * mgr->page_size);
- munmap (mgr->latchmgr, mgr->page_size);
-#else
- FlushViewOfFile(mgr->latchmgr, 0);
- UnmapViewOfFile(mgr->latchmgr);
- CloseHandle(mgr->halloc);
-#endif
-#ifdef unix
- close (mgr->idx);
- free (mgr->pool);
- free (mgr->hash);
- free (mgr->latch);
- free (mgr->pooladvise);
- free (mgr);
-#else
- FlushFileBuffers(mgr->idx);
- CloseHandle(mgr->idx);
- GlobalFree (mgr->pool);
- GlobalFree (mgr->hash);
- GlobalFree (mgr->latch);
- GlobalFree (mgr);
-#endif
-}
-
-// close and release memory
-
-void bt_close (BtDb *bt)
-{
-#ifdef unix
- if ( bt->mem )
- free (bt->mem);
-#else
- if ( bt->mem)
- VirtualFree (bt->mem, 0, MEM_RELEASE);
-#endif
- free (bt);
-}
-
-// open/create new btree buffer manager
-
-// call with file_name, BT_openmode, bits in page size (e.g. 16),
-// size of mapped page pool (e.g. 8192)
-
-BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolmax, uint segsize, uint hashsize)
-{
-uint lvl, attr, cacheblk, last, slot, idx;
-uint nlatchpage, latchhash;
-BtLatchMgr *latchmgr;
-off64_t size;
-uint amt[1];
-BtMgr* mgr;
-BtKey key;
-int flag;
-
-#ifndef unix
-SYSTEM_INFO sysinfo[1];
-#endif
-
- // determine sanity of page size and buffer pool
-
- if( bits > BT_maxbits )
- bits = BT_maxbits;
- else if( bits < BT_minbits )
- bits = BT_minbits;
-
- if( !poolmax )
- return NULL; // must have buffer pool
-
-#ifdef unix
- mgr = calloc (1, sizeof(BtMgr));
-
- mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
-
- if( mgr->idx == -1 )
- return free(mgr), NULL;
-
- cacheblk = 4096; // minimum mmap segment size for unix
-
-#else
- mgr = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtMgr));
- attr = FILE_ATTRIBUTE_NORMAL;
- mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
-
- if( mgr->idx == INVALID_HANDLE_VALUE )
- return GlobalFree(mgr), NULL;
-
- // normalize cacheblk to multiple of sysinfo->dwAllocationGranularity
- GetSystemInfo(sysinfo);
- cacheblk = sysinfo->dwAllocationGranularity;
-#endif
-
-#ifdef unix
- latchmgr = malloc (BT_maxpage);
- *amt = 0;
-
- // read minimum page size to get root info
-
- if( size = lseek (mgr->idx, 0L, 2) ) {
- if( pread(mgr->idx, latchmgr, BT_minpage, 0) == BT_minpage )
- bits = latchmgr->alloc->bits;
- else
- return free(mgr), free(latchmgr), NULL;
- } else if( mode == BT_ro )
- return free(latchmgr), free (mgr), NULL;
-#else
- latchmgr = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
- size = GetFileSize(mgr->idx, amt);
-
- if( size || *amt ) {
- if( !ReadFile(mgr->idx, (char *)latchmgr, BT_minpage, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- bits = latchmgr->alloc->bits;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- mgr->page_size = 1 << bits;
- mgr->page_bits = bits;
-
- mgr->poolmax = poolmax;
- mgr->mode = mode;
-
- if( cacheblk < mgr->page_size )
- cacheblk = mgr->page_size;
-
- // mask for partial memmaps
-
- mgr->poolmask = (cacheblk >> bits) - 1;
-
- // see if requested size of pages per memmap is greater
-
- if( (1 << segsize) > mgr->poolmask )
- mgr->poolmask = (1 << segsize) - 1;
-
- mgr->seg_bits = 0;
-
- while( (1 << mgr->seg_bits) <= mgr->poolmask )
- mgr->seg_bits++;
-
- mgr->hashsize = hashsize;
-
-#ifdef unix
- mgr->pool = calloc (poolmax, sizeof(BtPool));
- mgr->hash = calloc (hashsize, sizeof(ushort));
- mgr->latch = calloc (hashsize, sizeof(BtSpinLatch));
- mgr->pooladvise = calloc (poolmax, (mgr->poolmask + 8) / 8);
-#else
- mgr->pool = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, poolmax * sizeof(BtPool));
- mgr->hash = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(ushort));
- mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtSpinLatch));
-#endif
-
- if( size || *amt )
- goto mgrlatch;
-
- // initialize an empty b-tree with latch page, root page, page of leaves
- // and page(s) of latches
-
- memset (latchmgr, 0, 1 << bits);
- nlatchpage = BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1;
- bt_putid(latchmgr->alloc->right, MIN_lvl+1+nlatchpage);
- latchmgr->alloc->bits = mgr->page_bits;
-
- latchmgr->nlatchpage = nlatchpage;
- latchmgr->latchtotal = nlatchpage * (mgr->page_size / sizeof(BtLatchSet));
-
- // initialize latch manager
-
- latchhash = (mgr->page_size - sizeof(BtLatchMgr)) / sizeof(BtHashEntry);
-
- // size of hash table = total number of latchsets
-
- if( latchhash > latchmgr->latchtotal )
- latchhash = latchmgr->latchtotal;
-
- latchmgr->latchhash = latchhash;
-
-#ifdef unix
- if( write (mgr->idx, latchmgr, mgr->page_size) < mgr->page_size )
- return free(latchmgr), bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- memset (latchmgr, 0, 1 << bits);
- latchmgr->alloc->bits = mgr->page_bits;
-
- for( lvl=MIN_lvl; lvl--; ) {
- slotptr(latchmgr->alloc, 1)->off = mgr->page_size - 3;
- bt_putid(slotptr(latchmgr->alloc, 1)->id, lvl ? MIN_lvl - lvl + 1 : 0); // next(lower) page number
- key = keyptr(latchmgr->alloc, 1);
- key->len = 2; // create stopper key
- key->key[0] = 0xff;
- key->key[1] = 0xff;
- latchmgr->alloc->min = mgr->page_size - 3;
- latchmgr->alloc->lvl = lvl;
- latchmgr->alloc->cnt = 1;
- latchmgr->alloc->act = 1;
-#ifdef unix
- if( write (mgr->idx, latchmgr, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
- // clear out latch manager locks
- // and rest of pages to round out segment
-
- memset(latchmgr, 0, mgr->page_size);
- last = MIN_lvl + 1;
-
- while( last <= ((MIN_lvl + 1 + nlatchpage) | mgr->poolmask) ) {
-#ifdef unix
- pwrite(mgr->idx, latchmgr, mgr->page_size, last << mgr->page_bits);
-#else
- SetFilePointer (mgr->idx, last << mgr->page_bits, NULL, FILE_BEGIN);
- if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- last++;
- }
-
-mgrlatch:
-#ifdef unix
- flag = PROT_READ | PROT_WRITE;
- mgr->latchmgr = mmap (0, mgr->page_size, flag, MAP_SHARED, mgr->idx, ALLOC_page * mgr->page_size);
- if( mgr->latchmgr == MAP_FAILED )
- return bt_mgrclose (mgr), NULL;
- mgr->latchsets = (BtLatchSet *)mmap (0, mgr->latchmgr->nlatchpage * mgr->page_size, flag, MAP_SHARED, mgr->idx, LATCH_page * mgr->page_size);
- if( mgr->latchsets == MAP_FAILED )
- return bt_mgrclose (mgr), NULL;
-#else
- flag = PAGE_READWRITE;
- mgr->halloc = CreateFileMapping(mgr->idx, NULL, flag, 0, (BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1 + LATCH_page) * mgr->page_size, NULL);
- if( !mgr->halloc )
- return bt_mgrclose (mgr), NULL;
-
- flag = FILE_MAP_WRITE;
- mgr->latchmgr = MapViewOfFile(mgr->halloc, flag, 0, 0, (BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1 + LATCH_page) * mgr->page_size);
- if( !mgr->latchmgr )
- return GetLastError(), bt_mgrclose (mgr), NULL;
-
- mgr->latchsets = (void *)((char *)mgr->latchmgr + LATCH_page * mgr->page_size);
-#endif
-
-#ifdef unix
- free (latchmgr);
-#else
- VirtualFree (latchmgr, 0, MEM_RELEASE);
-#endif
- return mgr;
-}
-
-// open BTree access method
-// based on buffer manager
-
-BtDb *bt_open (BtMgr *mgr)
-{
-BtDb *bt = malloc (sizeof(*bt));
-
- memset (bt, 0, sizeof(*bt));
- bt->mgr = mgr;
-#ifdef unix
- bt->mem = malloc (3 *mgr->page_size);
-#else
- bt->mem = VirtualAlloc(NULL, 3 * mgr->page_size, MEM_COMMIT, PAGE_READWRITE);
-#endif
- bt->frame = (BtPage)bt->mem;
- bt->zero = (BtPage)(bt->mem + 1 * mgr->page_size);
- bt->cursor = (BtPage)(bt->mem + 2 * mgr->page_size);
-
- memset(bt->zero, 0, mgr->page_size);
- return bt;
-}
-
-// compare two keys, returning > 0, = 0, or < 0
-// as the comparison value
-
-int keycmp (BtKey key1, unsigned char *key2, uint len2)
-{
-uint len1 = key1->len;
-int ans;
-
- if( ans = memcmp (key1->key, key2, len1 > len2 ? len2 : len1) )
- return ans;
-
- if( len1 > len2 )
- return 1;
- if( len1 < len2 )
- return -1;
-
- return 0;
-}
-
-// Latch Manager
-
-void bt_readlock(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_rdlock (latch->lock);
-#else
- AcquireSRWLockShared (latch->srw);
-#endif
-}
-
-// wait for other read and write latches to relinquish
-
-void bt_writelock(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_wrlock (latch->lock);
-#else
- AcquireSRWLockExclusive (latch->srw);
-#endif
-}
-
-// try to obtain write lock
-
-// return 1 if obtained,
-// 0 if already write or read locked
-
-int bt_writetry(BtLatch *latch)
-{
-int result = 0;
-
-#ifdef unix
- result = !pthread_rwlock_trywrlock (latch->lock);
-#else
- result = TryAcquireSRWLockExclusive (latch->srw);
-#endif
- return result;
-}
-
-// clear write mode
-
-void bt_releasewrite(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_unlock (latch->lock);
-#else
- ReleaseSRWLockExclusive (latch->srw);
-#endif
-}
-
-// decrement reader count
-
-void bt_releaseread(BtLatch *latch)
-{
-#ifdef unix
- pthread_rwlock_unlock (latch->lock);
-#else
- ReleaseSRWLockShared (latch->srw);
-#endif
-}
-
-// Buffer Pool mgr
-
-// find segment in pool
-// must be called with hashslot idx locked
-// return NULL if not there
-// otherwise return node
-
-BtPool *bt_findpool(BtDb *bt, uid page_no, uint idx)
-{
-BtPool *pool;
-uint slot;
-
- // compute start of hash chain in pool
-
- if( slot = bt->mgr->hash[idx] )
- pool = bt->mgr->pool + slot;
- else
- return NULL;
-
- page_no &= ~bt->mgr->poolmask;
-
- while( pool->basepage != page_no )
- if( pool = pool->hashnext )
- continue;
- else
- return NULL;
-
- return pool;
-}
-
-// add segment to hash table
-
-void bt_linkhash(BtDb *bt, BtPool *pool, uid page_no, int idx)
-{
-BtPool *node;
-uint slot;
-
- pool->hashprev = pool->hashnext = NULL;
- pool->basepage = page_no & ~bt->mgr->poolmask;
- pool->lru = 1;
-
- if( slot = bt->mgr->hash[idx] ) {
- node = bt->mgr->pool + slot;
- pool->hashnext = node;
- node->hashprev = pool;
- }
-
- bt->mgr->hash[idx] = pool->slot;
-}
-
-// find best segment to evict from buffer pool
-
-BtPool *bt_findlru (BtDb *bt, uint hashslot)
-{
-unsigned long long int target = ~0LL;
-BtPool *pool = NULL, *node;
-
- if( !hashslot )
- return NULL;
-
- node = bt->mgr->pool + hashslot;
-
- // scan pool entries under hash table slot
-
- do {
- if( node->pin )
- continue;
- if( node->lru > target )
- continue;
- target = node->lru;
- pool = node;
- } while( node = node->hashnext );
-
- return pool;
-}
-
-// map new buffer pool segment to virtual memory
-
-BTERR bt_mapsegment(BtDb *bt, BtPool *pool, uid page_no)
-{
-off64_t off = (page_no & ~bt->mgr->poolmask) << bt->mgr->page_bits;
-off64_t limit = off + ((bt->mgr->poolmask+1) << bt->mgr->page_bits);
-int flag;
-
-#ifdef unix
- flag = PROT_READ | ( bt->mgr->mode == BT_ro ? 0 : PROT_WRITE );
- pool->map = mmap (0, (bt->mgr->poolmask+1) << bt->mgr->page_bits, flag, MAP_SHARED, bt->mgr->idx, off);
- if( pool->map == MAP_FAILED )
- return bt->err = BTERR_map;
- // clear out madvise issued bits
- memset (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8) / 8), 0, (bt->mgr->poolmask + 8)/8);
-#else
- flag = ( bt->mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
- pool->hmap = CreateFileMapping(bt->mgr->idx, NULL, flag, (DWORD)(limit >> 32), (DWORD)limit, NULL);
- if( !pool->hmap )
- return bt->err = BTERR_map;
-
- flag = ( bt->mgr->mode == BT_ro ? FILE_MAP_READ : FILE_MAP_WRITE );
- pool->map = MapViewOfFile(pool->hmap, flag, (DWORD)(off >> 32), (DWORD)off, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
- if( !pool->map )
- return bt->err = BTERR_map;
-#endif
- return bt->err = 0;
-}
-
-// calculate page within pool
-
-BtPage bt_page (BtDb *bt, BtPool *pool, uid page_no)
-{
-uint subpage = (uint)(page_no & bt->mgr->poolmask); // page within mapping
-BtPage page;
-
- page = (BtPage)(pool->map + (subpage << bt->mgr->page_bits));
-#ifdef unix
- {
- uint idx = subpage / 8;
- uint bit = subpage % 8;
-
- if( ~((bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] >> bit) & 1 ) {
- madvise (page, bt->mgr->page_size, MADV_WILLNEED);
- (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] |= 1 << bit;
- }
- }
-#endif
- return page;
-}
-
-// release pool pin
-
-void bt_unpinpool (BtPool *pool)
-{
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, -1);
-#else
- _InterlockedDecrement16 (&pool->pin);
-#endif
-}
-
-// find or place requested page in segment-pool
-// return pool table entry, incrementing pin
-
-BtPool *bt_pinpool(BtDb *bt, uid page_no)
-{
-BtPool *pool, *node, *next;
-uint slot, idx, victim;
-BtLatchSet *set;
-
- // lock hash table chain
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_spinreadlock (&bt->mgr->latch[idx]);
-
- // look up in hash table
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleaseread (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // upgrade to write lock
-
- bt_spinreleaseread (&bt->mgr->latch[idx]);
- bt_spinwritelock (&bt->mgr->latch[idx]);
-
- // try to find page in pool with write lock
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // allocate a new pool node
- // and add to hash table
-
-#ifdef unix
- slot = __sync_fetch_and_add(&bt->mgr->poolcnt, 1);
-#else
- slot = _InterlockedIncrement16 (&bt->mgr->poolcnt) - 1;
-#endif
-
- if( ++slot < bt->mgr->poolmax ) {
- pool = bt->mgr->pool + slot;
- pool->slot = slot;
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-
- // pool table is full
- // find best pool entry to evict
-
-#ifdef unix
- __sync_fetch_and_add(&bt->mgr->poolcnt, -1);
-#else
- _InterlockedDecrement16 (&bt->mgr->poolcnt);
-#endif
-
- while( 1 ) {
-#ifdef unix
- victim = __sync_fetch_and_add(&bt->mgr->evicted, 1);
-#else
- victim = _InterlockedIncrement16 (&bt->mgr->evicted) - 1;
-#endif
- victim %= bt->mgr->hashsize;
-
- // try to get write lock
- // skip entry if not obtained
-
- if( !bt_spinwritetry (&bt->mgr->latch[victim]) )
- continue;
-
- // if cache entry is empty
- // or no slots are unpinned
- // skip this entry
-
- if( !(pool = bt_findlru(bt, bt->mgr->hash[victim])) ) {
- bt_spinreleasewrite (&bt->mgr->latch[victim]);
- continue;
- }
-
- // unlink victim pool node from hash table
-
- if( node = pool->hashprev )
- node->hashnext = pool->hashnext;
- else if( node = pool->hashnext )
- bt->mgr->hash[victim] = node->slot;
- else
- bt->mgr->hash[victim] = 0;
-
- if( node = pool->hashnext )
- node->hashprev = pool->hashprev;
-
- bt_spinreleasewrite (&bt->mgr->latch[victim]);
-
- // remove old file mapping
-#ifdef unix
- munmap (pool->map, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
-#else
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
-#endif
- pool->map = NULL;
-
- // create new pool mapping
- // and link into hash table
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-}
-
-// place write, read, or parent lock on requested page_no.
-// pin to buffer pool and return latchset pointer
-
-void bt_lockpage(BtLock mode, BtLatchSet *set)
-{
- switch( mode ) {
- case BtLockRead:
- bt_readlock (set->readwr);
- break;
- case BtLockWrite:
- bt_writelock (set->readwr);
- break;
- case BtLockAccess:
- bt_readlock (set->access);
- break;
- case BtLockDelete:
- bt_writelock (set->access);
- break;
- case BtLockParent:
- bt_writelock (set->parent);
- break;
- }
-}
-
-// remove write, read, or parent lock on requested page_no.
-
-void bt_unlockpage(BtLock mode, BtLatchSet *set)
-{
- switch( mode ) {
- case BtLockRead:
- bt_releaseread (set->readwr);
- break;
- case BtLockWrite:
- bt_releasewrite (set->readwr);
- break;
- case BtLockAccess:
- bt_releaseread (set->access);
- break;
- case BtLockDelete:
- bt_releasewrite (set->access);
- break;
- case BtLockParent:
- bt_releasewrite (set->parent);
- break;
- }
-}
-
-// allocate a new page and write page into it
-
-uid bt_newpage(BtDb *bt, BtPage page)
-{
-BtLatchSet *set;
-BtPool *pool;
-uid new_page;
-BtPage pmap;
-int reuse;
-
- // lock allocation page
-
- bt_spinwritelock(bt->mgr->latchmgr->lock);
-
- // use empty chain first
- // else allocate empty page
-
- if( new_page = bt_getid(bt->mgr->latchmgr->alloc[1].right) ) {
- if( pool = bt_pinpool (bt, new_page) )
- pmap = bt_page (bt, pool, new_page);
- else
- return 0;
- bt_putid(bt->mgr->latchmgr->alloc[1].right, bt_getid(pmap->right));
- bt_unpinpool (pool);
- reuse = 1;
- } else {
- new_page = bt_getid(bt->mgr->latchmgr->alloc->right);
- bt_putid(bt->mgr->latchmgr->alloc->right, new_page+1);
- reuse = 0;
- }
-#ifdef unix
- // if writing first page of pool block, zero last page in the block
-
- if ( !reuse && bt->mgr->poolmask > 0 && (new_page & bt->mgr->poolmask) == 0 )
- {
- // use zero buffer to write zeros
- if ( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->poolmask) << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
- }
-
- // unlock allocation latch
-
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
-
- if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
-
-#else
- // unlock allocation latch
-
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
-
- // bring new page into pool and copy page.
- // this will extend the file into the new pages.
- // NB -- no latch required
-
- if( pool = bt_pinpool (bt, new_page) )
- pmap = bt_page (bt, pool, new_page);
- else
- return 0;
-
- memcpy(pmap, page, bt->mgr->page_size);
- bt_unpinpool (pool);
-#endif
- return new_page;
-}
-
-// find slot in page for given key at a given level
-
-int bt_findslot (BtDb *bt, unsigned char *key, uint len)
-{
-uint diff, higher = bt->page->cnt, low = 1, slot;
-
- // low is the lowest candidate, higher is already
- // tested as .ge. the given key, loop ends when they meet
-
- while( diff = higher - low ) {
- slot = low + ( diff >> 1 );
- if( keycmp (keyptr(bt->page, slot), key, len) < 0 )
- low = slot + 1;
- else
- higher = slot;
- }
-
- return higher;
-}
-
-// find and load page at given level for given key
-// leave page rd or wr locked as requested
-
-int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, BtLock lock)
-{
-uid page_no = ROOT_page, prevpage = 0;
-BtLatchSet *set, *prevset;
-uint drill = 0xff, slot;
-uint mode, prevmode;
-BtPool *prevpool;
-
- // start at root of btree and drill down
-
- do {
- // determine lock mode of drill level
- mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead;
-
- // obtain latch set for this page
-
- bt->set = bt_pinlatch (bt, page_no);
- bt->page_no = page_no;
-
- // pin page contents
-
- if( bt->pool = bt_pinpool (bt, page_no) )
- bt->page = bt_page (bt, bt->pool, page_no);
- else
- return 0;
-
- // obtain access lock using lock chaining with Access mode
-
- if( page_no > ROOT_page )
- bt_lockpage(BtLockAccess, bt->set);
-
- // now unlock and unpin our (possibly foster) parent
-
- if( prevpage ) {
- bt_unlockpage(prevmode, prevset);
- bt_unpinlatch (prevset);
- bt_unpinpool (prevpool);
- prevpage = 0;
- }
-
- // obtain read lock using lock chaining
-
- bt_lockpage(mode, bt->set);
-
- if( page_no > ROOT_page )
- bt_unlockpage(BtLockAccess, bt->set);
-
- // re-read and re-lock root after determining actual level of root
-
- if( page_no == ROOT_page )
- if( bt->page->lvl != drill) {
- drill = bt->page->lvl;
-
- if( lock == BtLockWrite && drill == lvl ) {
- bt_unlockpage(mode, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
- continue;
- }
- }
-
- prevpage = bt->page_no;
- prevpool = bt->pool;
- prevset = bt->set;
- prevmode = mode;
-
- // find key on page at this level
- // and either descend to requested level
- // or return key slot
-
- slot = bt_findslot (bt, key, len);
-
- // is this slot < foster child area
- // on the requested level?
-
- // if so, return actual slot even if dead
-
- if( slot <= bt->page->cnt - bt->page->foster )
- if( drill == lvl )
- return slot;
-
- // find next active slot
-
- // note: foster children are never dead
- // nor fence keys for interiour nodes
-
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
- continue;
- else
- return bt->err = BTERR_struct, 0; // last key shouldn't be deleted
-
- // is this slot < foster child area
- // if so, drill to next level
-
- if( slot <= bt->page->cnt - bt->page->foster )
- drill--;
-
- // continue right onto foster child
- // or down to next level.
-
- page_no = bt_getid(slotptr(bt->page, slot)->id);
-
- } while( page_no );
-
- // return error on end of chain
-
- bt->err = BTERR_struct;
- return 0; // return error
-}
-
-// find and delete key on page by marking delete flag bit
-// when leaf page becomes empty, delete it from the btree
-
-BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len)
-{
-unsigned char leftkey[256];
-BtLatchSet *rset, *set;
-BtPool *pool, *rpool;
-BtPage rpage, page;
-uid page_no, right;
-uint slot, tod;
-BtKey ptr;
-
- if( slot = bt_loadpage (bt, key, len, 0, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // if key is found delete it, otherwise ignore request
- // note that fence keys of interiour nodes are not deleted.
-
- if( bt->found = !keycmp (ptr, key, len) )
- if( bt->found = slotptr(bt->page, slot)->dead == 0 ) {
- slotptr(bt->page,slot)->dead = 1;
- if( slot < bt->page->cnt )
- bt->page->dirty = 1;
- bt->page->act--;
- }
-
- page_no = bt->page_no;
- pool = bt->pool;
- page = bt->page;
- set = bt->set;
-
- // return if page is not empty or not found
-
- if( page->act || !bt->found ) {
- bt_unlockpage(BtLockWrite, set);
- bt_unpinlatch (set);
- bt_unpinpool (pool);
- return bt->err;
- }
-
- // cache copy of fence key of empty node
-
- ptr = keyptr(page, page->cnt);
- memcpy(leftkey, ptr, ptr->len + 1);
-
- // release write lock on empty node
- // obtain Parent lock
-
- bt_unlockpage(BtLockWrite, set);
- bt_lockpage(BtLockParent, set);
-
- // load and lock parent to see
- // if delete of empty node is OK
- // ie, not a fence key of parent
-
- while( 1 ) {
- if( slot = bt_loadpage (bt, leftkey+1, *leftkey, 1, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // does parent level contain our fence key yet?
- // and is it free of foster children?
-
- if( !bt->page->foster )
- if( !keycmp (ptr, leftkey+1, *leftkey) )
- break;
-
- bt_unlockpage(BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- }
-
- // find our left fence key
-
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
- continue;
- else
- return bt->err = BTERR_struct; // last key shouldn't be deleted
-
- // now we have both parent and child
-
- bt_lockpage(BtLockDelete, set);
- bt_lockpage(BtLockWrite, set);
-
- // return if page has no right sibling within parent
- // or if empty node is no longer empty
-
- if( page->act || slot == bt->page->cnt ) {
- // unpin parent
- bt_unlockpage(BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
- // unpin empty node
- bt_unlockpage(BtLockParent, set);
- bt_unlockpage(BtLockDelete, set);
- bt_unlockpage(BtLockWrite, set);
- bt_unpinlatch (set);
- bt_unpinpool (pool);
- return bt->err;
- }
-
- // lock and map our right page
- // note that it cannot be our foster child
- // since the our node is empty
-
- right = bt_getid(page->right);
-
- if( rpool = bt_pinpool (bt, right) )
- rpage = bt_page (bt, rpool, right);
- else
- return bt->err;
-
- rset = bt_pinlatch (bt, right);
- bt_lockpage(BtLockWrite, rset);
- bt_lockpage(BtLockDelete, rset);
-
- // pull contents of right page into empty page
-
- memcpy (page, rpage, bt->mgr->page_size);
-
- // delete left parent slot for old empty page
- // and redirect right parent slot to it
-
- bt->page->act--;
- bt->page->dirty = 1;
- slotptr(bt->page, slot)->dead = 1;
-
- while( slot++ < bt->page->cnt )
- if( !slotptr(bt->page, slot)->dead )
- break;
-
- bt_putid(slotptr(bt->page,slot)->id, page_no);
-
- // release parent level lock
- // and our empty node lock
-
- bt_unlockpage(BtLockWrite, set);
- bt_unlockpage(BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
-
- // add killed right block to free chain
- // lock latch mgr
-
- bt_spinwritelock(bt->mgr->latchmgr->lock);
-
- // store free chain in allocation page second right
- bt_putid(rpage->right, bt_getid(bt->mgr->latchmgr->alloc[1].right));
- bt_putid(bt->mgr->latchmgr->alloc[1].right, right);
-
- // unlock latch mgr and right page
-
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
-
- bt_unlockpage(BtLockWrite, rset);
- bt_unlockpage(BtLockDelete, rset);
- bt_unpinlatch (rset);
- bt_unpinpool (rpool);
-
- // remove ParentModify lock
-
- bt_unlockpage(BtLockParent, set);
- bt_unlockpage(BtLockDelete, set);
- bt_unpinlatch (set);
- bt_unpinpool (pool);
- return 0;
-}
-
-// find key in leaf level and return row-id
-
-uid bt_findkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-BtKey ptr;
-uid id;
-
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- ptr = keyptr(bt->page, slot);
- else
- return 0;
-
- // if key exists, return row-id
- // otherwise return 0
-
- if( slot <= bt->page->cnt && !keycmp (ptr, key, len) )
- id = bt_getid(slotptr(bt->page,slot)->id);
- else
- id = 0;
-
- bt_unlockpage (BtLockRead, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
- return id;
-}
-
-// check page for space available,
-// clean if necessary and return
-// 0 - page needs splitting
-// >0 new slot value
-
-uint bt_cleanpage(BtDb *bt, uint amt, uint slot)
-{
-uint nxt = bt->mgr->page_size;
-BtPage page = bt->page;
-uint cnt = 0, idx = 0;
-uint max = page->cnt;
-uint newslot;
-BtKey key;
-
- if( page->min >= (max+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return slot;
-
- // skip cleanup if nothing to reclaim
-
- if( !page->dirty )
- return 0;
-
- memcpy (bt->frame, page, bt->mgr->page_size);
-
- // skip page info and set rest of page to zero
-
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- page->dirty = 0;
- page->act = 0;
-
- // try cleaning up page first
-
- // always leave fence key in the array
- // otherwise, remove deleted key
-
- // note: foster children are never dead
- // nor are fence keys for interiour nodes
-
- while( cnt++ < max ) {
- if( cnt == slot )
- newslot = idx + 1;
- else if( cnt < max && slotptr(bt->frame,cnt)->dead )
- continue;
-
- // copy key
-
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
-
- // copy slot
- memcpy(slotptr(page, ++idx)->id, slotptr(bt->frame, cnt)->id, BtId);
- if( !(slotptr(page, idx)->dead = slotptr(bt->frame, cnt)->dead) )
- page->act++;
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // see if page has enough space now, or does it need splitting?
-
- if( page->min >= (idx+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return newslot;
-
- return 0;
-}
-
-// add key to current page
-// page must already be writelocked
-
-void bt_addkeytopage (BtDb *bt, uint slot, unsigned char *key, uint len, uid id, uint tod)
-{
-BtPage page = bt->page;
-uint idx;
-
- // find next available dead slot and copy key onto page
- // note that foster children on the page are never dead
-
- // look for next hole, but stay back from the fence key
-
- for( idx = slot; idx < page->cnt; idx++ )
- if( slotptr(page, idx)->dead )
- break;
-
- if( idx == page->cnt )
- idx++, page->cnt++;
-
- page->act++;
-
- // now insert key into array before slot
-
- while( idx > slot )
- *slotptr(page, idx) = *slotptr(page, idx -1), idx--;
-
- page->min -= len + 1;
- ((unsigned char *)page)[page->min] = len;
- memcpy ((unsigned char *)page + page->min +1, key, len );
-
- bt_putid(slotptr(page,slot)->id, id);
- slotptr(page, slot)->off = page->min;
- slotptr(page, slot)->tod = tod;
- slotptr(page, slot)->dead = 0;
-}
-
-// split the root and raise the height of the btree
-// call with current page locked and page no of foster child
-// return with current page (root) unlocked
-
-BTERR bt_splitroot(BtDb *bt, uid right)
-{
-uint nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-BtPage root = bt->page;
-uid new_page;
-BtKey key;
-
- // Obtain an empty page to use, and copy the left page
- // contents into it from the root. Strip foster child key.
- // (it's the stopper key)
-
- memset (slotptr(root, root->cnt), 0, sizeof(BtSlot));
- root->dirty = 1;
- root->foster--;
- root->act--;
- root->cnt--;
-
- // Save left fence key.
-
- key = keyptr(root, root->cnt);
- memcpy (fencekey, key, key->len + 1);
-
- // copy the lower keys into a new left page
-
- if( !(new_page = bt_newpage(bt, root)) )
- return bt->err;
-
- // preserve the page info at the bottom
- // and set rest of the root to zero
-
- memset (root+1, 0, bt->mgr->page_size - sizeof(*root));
-
- // insert left fence key on empty newroot page
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 1)->id, new_page);
- slotptr(root, 1)->off = nxt;
-
- // insert stopper key on newroot page
- // and increase the root height
-
- nxt -= 3;
- fencekey[0] = 2;
- fencekey[1] = 0xff;
- fencekey[2] = 0xff;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 2)->id, right);
- slotptr(root, 2)->off = nxt;
-
- bt_putid(root->right, 0);
- root->min = nxt; // reset lowest used offset and key count
- root->cnt = 2;
- root->act = 2;
- root->lvl++;
-
- // release and unpin root (bt->page)
-
- bt_unlockpage(BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
- return 0;
-}
-
-// split already locked full node
-// in current page variables
-// return unlocked and unpinned.
-
-BTERR bt_splitpage (BtDb *bt)
-{
-uint slot, cnt, idx, max, nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-uid page_no = bt->page_no;
-BtLatchSet *set = bt->set;
-BtPool *pool = bt->pool;
-BtPage page = bt->page;
-uint tod = time(NULL);
-uint lvl = page->lvl;
-uid new_page, right;
-BtKey key;
-
- // initialize frame buffer for right node
-
- memset (bt->frame, 0, bt->mgr->page_size);
- max = page->cnt - page->foster;
- tod = (uint)time(NULL);
- cnt = max / 2;
- idx = 0;
-
- // split higher half of keys to bt->frame
- // leaving old foster children in the left node,
- // and adding a new foster child there.
-
- while( cnt++ < max ) {
- key = keyptr(page, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)bt->frame + nxt, key, key->len + 1);
- memcpy(slotptr(bt->frame,++idx)->id, slotptr(page,cnt)->id, BtId);
- if( !(slotptr(bt->frame, idx)->dead = slotptr(page, cnt)->dead) )
- bt->frame->act++;
- slotptr(bt->frame, idx)->tod = slotptr(page, cnt)->tod;
- slotptr(bt->frame, idx)->off = nxt;
- }
-
- // transfer right link node to new right node
-
- if( page_no > ROOT_page ) {
- right = bt_getid (page->right);
- bt_putid(bt->frame->right, right);
- }
-
- bt->frame->bits = bt->mgr->page_bits;
- bt->frame->min = nxt;
- bt->frame->cnt = idx;
- bt->frame->lvl = lvl;
-
- // get new free page and write right frame to it.
-
- if( !(new_page = bt_newpage(bt, bt->frame)) )
- return bt->err;
-
- // remember fence key for new right page to add
- // as foster child to the left node
-
- key = keyptr(bt->frame, idx);
- memcpy (fencekey, key, key->len + 1);
-
- // update lower keys and foster children to continue in old page
-
- memcpy (bt->frame, page, bt->mgr->page_size);
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- nxt = bt->mgr->page_size;
- page->dirty = 0;
- page->act = 0;
- cnt = 0;
- idx = 0;
-
- // assemble page of smaller keys
- // to remain in the old page
-
- while( cnt++ < max / 2 ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- if( !(slotptr(page, idx)->dead = slotptr(bt->frame, cnt)->dead) )
- page->act++;
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- }
-
- // insert new foster child for right page in queue
- // before any of the current foster children
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)page + nxt, fencekey, *fencekey + 1);
-
- bt_putid (slotptr(page,++idx)->id, new_page);
- slotptr(page, idx)->tod = tod;
- slotptr(page, idx)->off = nxt;
- page->foster++;
- page->act++;
-
- // continue with old foster child keys
- // note that none will be dead
-
- cnt = bt->frame->cnt - bt->frame->foster;
-
- while( cnt++ < bt->frame->cnt ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // link new right page
-
- bt_putid (page->right, new_page);
-
- // if current page is the root page, split it
-
- if( page_no == ROOT_page )
- return bt_splitroot (bt, new_page);
-
- // release wr lock on our page
-
- bt_unlockpage (BtLockWrite, set);
-
- // obtain ParentModification lock for current page
- // to fix new fence key and oldest foster child on page
-
- bt_lockpage (BtLockParent, set);
-
- // get our new fence key to insert in parent node
-
- bt_lockpage (BtLockRead, set);
-
- key = keyptr(page, page->cnt-1);
- memcpy (fencekey, key, key->len+1);
-
- bt_unlockpage (BtLockRead, set);
-
- if( bt_insertkey (bt, fencekey + 1, *fencekey, page_no, tod, lvl + 1) )
- return bt->err;
-
- // lock our page for writing
-
- bt_lockpage (BtLockRead, set);
-
- // switch old parent key from us to our oldest foster child
-
- key = keyptr(page, page->cnt);
- memcpy (fencekey, key, key->len+1);
-
- new_page = bt_getid (slotptr(page, page->cnt)->id);
- bt_unlockpage (BtLockRead, set);
-
- if( bt_insertkey (bt, fencekey + 1, *fencekey, new_page, tod, lvl + 1) )
- return bt->err;
-
- // now that it has its own parent pointer,
- // remove oldest foster child from our page
-
- bt_lockpage (BtLockWrite, set);
- memset (slotptr(page, page->cnt), 0, sizeof(BtSlot));
- page->dirty = 1;
- page->foster--;
- page->cnt--;
- page->act--;
-
- // unlock and unpin
-
- bt_unlockpage (BtLockWrite, set);
- bt_unlockpage (BtLockParent, set);
- bt_unpinlatch (set);
- bt_unpinpool (pool);
- return 0;
-}
-
-// Insert new key into the btree at leaf level.
-
-BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod, uint lvl)
-{
-uint slot, idx;
-BtPage page;
-BtKey ptr;
-
- while( 1 ) {
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- {
- if ( !bt->err )
- bt->err = BTERR_ovflw;
- return bt->err;
- }
-
- // if key already exists, update id and return
-
- page = bt->page;
-
- if( !keycmp (ptr, key, len) ) {
- if( slotptr(page, slot)->dead )
- page->act++;
- slotptr(page, slot)->dead = 0;
- slotptr(page, slot)->tod = tod;
- bt_putid(slotptr(page,slot)->id, id);
- bt_unlockpage(BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
- return bt->err;
- }
-
- // check if page has enough space
-
- if( slot = bt_cleanpage (bt, len, slot) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- }
-
- bt_addkeytopage (bt, slot, key, len, id, tod);
-
- bt_unlockpage (BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
- return 0;
-}
-
-// cache page of keys into cursor and return starting slot for given key
-
-uint bt_startkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-
- // cache page for retrieval
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- memcpy (bt->cursor, bt->page, bt->mgr->page_size);
-
- bt->cursor_page = bt->page_no;
-
- bt_unlockpage(BtLockRead, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
- return slot;
-}
-
-// return next slot for cursor page
-// or slide cursor right into next page
-
-uint bt_nextkey (BtDb *bt, uint slot)
-{
-BtLatchSet *set;
-BtPool *pool;
-BtPage page;
-uid right;
-
- do {
- right = bt_getid(bt->cursor->right);
- while( slot++ < bt->cursor->cnt - bt->cursor->foster )
- if( slotptr(bt->cursor,slot)->dead )
- continue;
- else if( right || (slot < bt->cursor->cnt - bt->cursor->foster) )
- return slot;
- else
- break;
-
- if( !right )
- break;
-
- bt->cursor_page = right;
- if( pool = bt_pinpool (bt, right) )
- page = bt_page (bt, pool, right);
- else
- return 0;
-
- set = bt_pinlatch (bt, right);
- bt_lockpage(BtLockRead, set);
-
- memcpy (bt->cursor, page, bt->mgr->page_size);
-
- bt_unlockpage(BtLockRead, set);
- bt_unpinlatch (set);
- bt_unpinpool (pool);
- slot = 0;
- } while( 1 );
-
- return bt->err = 0;
-}
-
-BtKey bt_key(BtDb *bt, uint slot)
-{
- return keyptr(bt->cursor, slot);
-}
-
-uid bt_uid(BtDb *bt, uint slot)
-{
- return bt_getid(slotptr(bt->cursor,slot)->id);
-}
-
-uint bt_tod(BtDb *bt, uint slot)
-{
- return slotptr(bt->cursor,slot)->tod;
-}
-
-
-#ifdef STANDALONE
-
-typedef struct {
- char type, idx;
- char *infile;
- BtMgr *mgr;
- int num;
-} ThreadArg;
-
-// standalone program to index file of keys
-// then list them onto std-out
-
-#ifdef unix
-void *index_file (void *arg)
-#else
-uint __stdcall index_file (void *arg)
-#endif
-{
-int line = 0, found = 0, cnt = 0;
-uid next, page_no = LEAF_page; // start on first page of leaves
-unsigned char key[256];
-ThreadArg *args = arg;
-int ch, len = 0, slot;
-BtLatchSet *set;
-time_t tod[1];
-BtPool *pool;
-BtPage page;
-BtKey ptr;
-BtDb *bt;
-FILE *in;
-
- bt = bt_open (args->mgr);
- time (tod);
-
- switch(args->type | 0x20)
- {
- case 'w':
- fprintf(stderr, "started indexing for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
-
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_insertkey (bt, key, len, line, *tod, 0) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys\n", args->infile, line);
- break;
-
- case 'd':
- fprintf(stderr, "started deleting keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_deletekey (bt, key, len) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for keys, %d \n", args->infile, line);
- break;
-
- case 'f':
- fprintf(stderr, "started finding keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_findkey (bt, key, len) )
- found++;
- else if( bt->err )
- fprintf(stderr, "Error %d Syserr %d Line: %d\n", bt->err, errno, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys, found %d\n", args->infile, line, found);
- break;
-
- case 's':
- len = key[0] = 0;
-
- fprintf(stderr, "started reading\n");
-
- if( slot = bt_startkey (bt, key, len) )
- slot--;
- else
- fprintf(stderr, "Error %d in StartKey. Syserror: %d\n", bt->err, errno), exit(0);
-
- while( slot = bt_nextkey (bt, slot) ) {
- ptr = bt_key(bt, slot);
- fwrite (ptr->key, ptr->len, 1, stdout);
- fputc ('\n', stdout);
- }
-
- break;
-
- case 'c':
- fprintf(stderr, "started reading\n");
-
- do {
- if( pool = bt_pinpool (bt, page_no) )
- page = bt_page (bt, pool, page_no);
- else
- break;
- set = bt_pinlatch (bt, page_no);
- bt_lockpage (BtLockRead, set);
- cnt += page->act;
- next = bt_getid (page->right);
- bt_unlockpage (BtLockRead, set);
- bt_unpinlatch (set);
- bt_unpinpool (pool);
- } while( page_no = next );
-
- cnt--; // remove stopper key
- fprintf(stderr, " Total keys read %d\n", cnt);
- break;
- }
-
- bt_close (bt);
-#ifdef unix
- return NULL;
-#else
- return 0;
-#endif
-}
-
-typedef struct timeval timer;
-
-int main (int argc, char **argv)
-{
-int idx, cnt, len, slot, err;
-int segsize, bits = 16;
-#ifdef unix
-pthread_t *threads;
-timer start, stop;
-#else
-time_t start[1], stop[1];
-HANDLE *threads;
-#endif
-double real_time;
-ThreadArg *args;
-uint poolsize = 0;
-int num = 0;
-char key[1];
-BtMgr *mgr;
-BtKey ptr;
-BtDb *bt;
-
- if( argc < 3 ) {
- fprintf (stderr, "Usage: %s idx_file Read/Write/Scan/Delete/Find [page_bits mapped_segments seg_bits line_numbers src_file1 src_file2 ... ]\n", argv[0]);
- fprintf (stderr, " where page_bits is the page size in bits\n");
- fprintf (stderr, " mapped_segments is the number of mmap segments in buffer pool\n");
- fprintf (stderr, " seg_bits is the size of individual segments in buffer pool in pages in bits\n");
- fprintf (stderr, " line_numbers = 1 to append line numbers to keys\n");
- fprintf (stderr, " src_file1 thru src_filen are files of keys separated by newline\n");
- exit(0);
- }
-
-#ifdef unix
- gettimeofday(&start, NULL);
-#else
- time(start);
-#endif
-
- if( argc > 3 )
- bits = atoi(argv[3]);
-
- if( argc > 4 )
- poolsize = atoi(argv[4]);
-
- if( !poolsize )
- fprintf (stderr, "Warning: no mapped_pool\n");
-
- if( poolsize > 65535 )
- fprintf (stderr, "Warning: mapped_pool > 65535 segments\n");
-
- if( argc > 5 )
- segsize = atoi(argv[5]);
- else
- segsize = 4; // 16 pages per mmap segment
-
- if( argc > 6 )
- num = atoi(argv[6]);
-
- cnt = argc - 7;
-#ifdef unix
- threads = malloc (cnt * sizeof(pthread_t));
-#else
- threads = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, cnt * sizeof(HANDLE));
-#endif
- args = malloc (cnt * sizeof(ThreadArg));
-
- mgr = bt_mgr ((argv[1]), BT_rw, bits, poolsize, segsize, poolsize / 8);
-
- if( !mgr ) {
- fprintf(stderr, "Index Open Error %s\n", argv[1]);
- exit (1);
- }
-
- // fire off threads
-
- for( idx = 0; idx < cnt; idx++ ) {
- args[idx].infile = argv[idx + 7];
- args[idx].type = argv[2][0];
- args[idx].mgr = mgr;
- args[idx].num = num;
- args[idx].idx = idx;
-#ifdef unix
- if( err = pthread_create (threads + idx, NULL, index_file, args + idx) )
- fprintf(stderr, "Error creating thread %d\n", err);
-#else
- threads[idx] = (HANDLE)_beginthreadex(NULL, 65536, index_file, args + idx, 0, NULL);
-#endif
- }
-
- // wait for termination
-
-#ifdef unix
- for( idx = 0; idx < cnt; idx++ )
- pthread_join (threads[idx], NULL);
- gettimeofday(&stop, NULL);
- real_time = 1000.0 * ( stop.tv_sec - start.tv_sec ) + 0.001 * (stop.tv_usec - start.tv_usec );
-#else
- WaitForMultipleObjects (cnt, threads, TRUE, INFINITE);
-
- for( idx = 0; idx < cnt; idx++ )
- CloseHandle(threads[idx]);
-
- time (stop);
- real_time = 1000 * (*stop - *start);
-#endif
- fprintf(stderr, " Time to complete: %.2f seconds\n", real_time/1000);
- bt_mgrclose (mgr);
-}
-
-#endif //STANDALONE
+++ /dev/null
-// foster btree version f
-// 17 JAN 2014
-
-// author: karl malbrain, malbrain@cal.berkeley.edu
-
-/*
-This work, including the source code, documentation
-and related data, is placed into the public domain.
-
-The orginal author is Karl Malbrain.
-
-THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
-OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
-MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
-ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
-RESULTING FROM THE USE, MODIFICATION, OR
-REDISTRIBUTION OF THIS SOFTWARE.
-*/
-
-// Please see the project home page for documentation
-// code.google.com/p/high-concurrency-btree
-
-#define _FILE_OFFSET_BITS 64
-#define _LARGEFILE64_SOURCE
-
-#ifdef linux
-#define _GNU_SOURCE
-#endif
-
-#ifdef unix
-#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <sys/time.h>
-#include <sys/mman.h>
-#include <errno.h>
-#include <pthread.h>
-#else
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <fcntl.h>
-#include <process.h>
-#include <intrin.h>
-#endif
-
-#include <memory.h>
-#include <string.h>
-
-typedef unsigned long long uid;
-
-#ifndef unix
-typedef unsigned long long off64_t;
-typedef unsigned short ushort;
-typedef unsigned int uint;
-#endif
-
-#define BT_ro 0x6f72 // ro
-#define BT_rw 0x7772 // rw
-
-#define BT_latchtable 128 // number of latch manager slots
-
-#define BT_maxbits 24 // maximum page size in bits
-#define BT_minbits 9 // minimum page size in bits
-#define BT_minpage (1 << BT_minbits) // minimum page size
-#define BT_maxpage (1 << BT_maxbits) // maximum page size
-
-/*
-There are five lock types for each node in three independent sets:
-1. (set 1) AccessIntent: Sharable. Going to Read the node. Incompatible with NodeDelete.
-2. (set 1) NodeDelete: Exclusive. About to release the node. Incompatible with AccessIntent.
-3. (set 2) ReadLock: Sharable. Read the node. Incompatible with WriteLock.
-4. (set 2) WriteLock: Exclusive. Modify the node. Incompatible with ReadLock and other WriteLocks.
-5. (set 3) ParentLock: Exclusive. Have parent adopt/delete maximum foster child from the node.
-*/
-
-typedef enum{
- BtLockAccess,
- BtLockDelete,
- BtLockRead,
- BtLockWrite,
- BtLockParent,
- BtLockPin
-}BtLock;
-
-// Define the length of the page and key pointers
-
-#define BtId 6
-
-// Page key slot definition.
-
-// If BT_maxbits is 15 or less, you can save 4 bytes
-// for each key stored by making the first two uints
-// into ushorts. You can also save 4 bytes by removing
-// the tod field from the key.
-
-// Keys are marked dead, but remain on the page until
-// it cleanup is called. The fence key (highest key) for
-// the page is always present, even after cleanup.
-
-typedef struct {
- uint off:BT_maxbits; // page offset for key start
- uint dead:1; // set for deleted key
- uint tod; // time-stamp for key
- unsigned char id[BtId]; // id associated with key
-} BtSlot;
-
-// The key structure occupies space at the upper end of
-// each page. It's a length byte followed by the value
-// bytes.
-
-typedef struct {
- unsigned char len;
- unsigned char key[1];
-} *BtKey;
-
-// The first part of an index page.
-// It is immediately followed
-// by the BtSlot array of keys.
-
-typedef struct Page {
- uint cnt; // count of keys in page
- uint act; // count of active keys
- uint min; // next key offset
- uint foster; // count of foster children
- unsigned char bits; // page size in bits
- unsigned char lvl:6; // level of page
- unsigned char kill:1; // page is being deleted
- unsigned char dirty:1; // page needs to be cleaned
- unsigned char right[BtId]; // page number to right
-} *BtPage;
-
-// mode & definition for hash latch implementation
-
-enum {
- Mutex = 1,
- Write = 2,
- Pending = 4,
- Share = 8
-} LockMode;
-
-// mutex locks the other fields
-// exclusive is set for write access
-// share is count of read accessors
-
-typedef struct {
- volatile ushort mutex:1;
- volatile ushort exclusive:1;
- volatile ushort pending:1;
- volatile ushort share:13;
-} BtSpinLatch;
-
-// hash table entries
-
-typedef struct {
- BtSpinLatch latch[1];
- volatile ushort slot; // Latch table entry at head of chain
-} BtHashEntry;
-
-// latch table lock structure
-// implements a fair read-write lock
-
-typedef struct {
-#ifdef unix
- pthread_rwlock_t lock[1];
-#else
- SRWLOCK srw[1];
-#endif
-} BtLatch;
-
-typedef struct {
- BtSpinLatch readwr[1]; // read/write page lock
- BtSpinLatch access[1]; // Access Intent/Page delete
- BtSpinLatch parent[1]; // adoption of foster children
- BtSpinLatch busy[1]; // slot is being moved between chains
- volatile ushort next; // next entry in hash table chain
- volatile ushort prev; // prev entry in hash table chain
- volatile ushort pin; // number of outstanding locks
- volatile ushort hash; // hash slot entry is under
- volatile uid page_no; // latch set page number
-} BtLatchSet;
-
-// The memory mapping pool table buffer manager entry
-
-typedef struct {
- unsigned long long int lru; // number of times accessed
- uid basepage; // mapped base page number
- char *map; // mapped memory pointer
- ushort pin; // mapped page pin counter
- ushort slot; // slot index in this array
- void *hashprev; // previous pool entry for the same hash idx
- void *hashnext; // next pool entry for the same hash idx
-#ifndef unix
- HANDLE hmap; // Windows memory mapping handle
-#endif
-} BtPool;
-
-// structure for latch manager on ALLOC_page
-
-typedef struct {
- struct Page alloc[2]; // next & free page_nos in right ptr
- BtSpinLatch lock[1]; // allocation area lite latch
- ushort latchdeployed; // highest number of latch entries deployed
- ushort nlatchpage; // number of latch pages at BT_latch
- ushort latchtotal; // number of page latch entries
- ushort latchhash; // number of latch hash table slots
- ushort latchvictim; // next latch entry to examine
- BtHashEntry table[0]; // the hash table
-} BtLatchMgr;
-
-// The object structure for Btree access
-
-typedef struct {
- uint page_size; // page size
- uint page_bits; // page size in bits
- uint seg_bits; // seg size in pages in bits
- uint mode; // read-write mode
-#ifdef unix
- int idx;
- char *pooladvise; // bit maps for pool page advisements
-#else
- HANDLE idx;
-#endif
- ushort poolcnt; // highest page pool node in use
- ushort poolmax; // highest page pool node allocated
- ushort poolmask; // total size of pages in mmap segment - 1
- ushort hashsize; // size of Hash Table for pool entries
- ushort evicted; // last evicted hash table slot
- ushort *hash; // hash table of pool entries
- BtPool *pool; // memory pool page segments
- BtSpinLatch *latch; // latches for pool hash slots
- BtLatchMgr *latchmgr; // mapped latch page from allocation page
- BtLatchSet *latchsets; // mapped latch set from latch pages
-#ifndef unix
- HANDLE halloc; // allocation and latch table handle
-#endif
-} BtMgr;
-
-typedef struct {
- BtMgr *mgr; // buffer manager for thread
- BtPage temp; // temporary frame buffer (memory mapped/file IO)
- BtPage cursor; // cached frame for start/next (never mapped)
- BtPage frame; // spare frame for the page split (never mapped)
- BtPage zero; // page frame for zeroes at end of file
- BtPage page; // current page
- uid page_no; // current page number
- uid cursor_page; // current cursor page number
- BtLatchSet *set; // current page latch set
- unsigned char *mem; // frame, cursor, page memory buffer
- int err; // last error
-} BtDb;
-
-typedef enum {
- BTERR_ok = 0,
- BTERR_struct,
- BTERR_ovflw,
- BTERR_lock,
- BTERR_map,
- BTERR_wrt,
- BTERR_hash,
- BTERR_latch
-} BTERR;
-
-// B-Tree functions
-extern void bt_close (BtDb *bt);
-extern BtDb *bt_open (BtMgr *mgr);
-extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod);
-extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
-extern uid bt_findkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
-extern uint bt_nextkey (BtDb *bt, uint slot);
-
-// manager functions
-extern BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolsize, uint segsize, uint hashsize);
-void bt_mgrclose (BtMgr *mgr);
-
-// Helper functions to return cursor slot values
-
-extern BtKey bt_key (BtDb *bt, uint slot);
-extern uid bt_uid (BtDb *bt, uint slot);
-extern uint bt_tod (BtDb *bt, uint slot);
-
-// BTree page number constants
-#define ALLOC_page 0 // allocation & lock manager hash table
-#define ROOT_page 1 // root of the btree
-#define LEAF_page 2 // first page of leaves
-#define LATCH_page 3 // pages for lock manager
-
-// Number of levels to create in a new BTree
-
-#define MIN_lvl 2
-
-// The page is allocated from low and hi ends.
-// The key offsets and row-id's are allocated
-// from the bottom, while the text of the key
-// is allocated from the top. When the two
-// areas meet, the page is split into two.
-
-// A key consists of a length byte, two bytes of
-// index number (0 - 65534), and up to 253 bytes
-// of key value. Duplicate keys are discarded.
-// Associated with each key is a 48 bit row-id.
-
-// The b-tree root is always located at page 1.
-// The first leaf page of level zero is always
-// located on page 2.
-
-// When to root page fills, it is split in two and
-// the tree height is raised by a new root at page
-// one with two keys.
-
-// Deleted keys are marked with a dead bit until
-// page cleanup The fence key for a node is always
-// present, even after deletion and cleanup.
-
-// Groups of pages called segments from the btree are
-// cached with memory mapping. A hash table is used to keep
-// track of the cached segments. This behaviour is controlled
-// by the cache block size parameter to bt_open.
-
-// To achieve maximum concurrency one page is locked at a time
-// as the tree is traversed to find leaf key in question.
-
-// An adoption traversal leaves the parent node locked as the
-// tree is traversed to the level in quesiton.
-
-// Page 0 is dedicated to lock for new page extensions,
-// and chains empty pages together for reuse.
-
-// Empty pages are chained together through the ALLOC page and reused.
-
-// Access macros to address slot and key values from the page
-
-#define slotptr(page, slot) (((BtSlot *)(page+1)) + (slot-1))
-#define keyptr(page, slot) ((BtKey)((unsigned char*)(page) + slotptr(page, slot)->off))
-
-void bt_putid(unsigned char *dest, uid id)
-{
-int i = BtId;
-
- while( i-- )
- dest[i] = (unsigned char)id, id >>= 8;
-}
-
-uid bt_getid(unsigned char *src)
-{
-uid id = 0;
-int i;
-
- for( i = 0; i < BtId; i++ )
- id <<= 8, id |= *src++;
-
- return id;
-}
-
-// wait until write lock mode is clear
-// and add 1 to the share count
-
-void bt_spinreadlock(BtSpinLatch *latch)
-{
-ushort prev;
-
- do {
-#ifdef unix
- while( __sync_fetch_and_or((ushort *)latch, Mutex) & Mutex )
- sched_yield();
-#else
- while( _InterlockedOr16((ushort *)latch, Mutex) & Mutex )
- SwitchToThread();
-#endif
-
- // see if exclusive request is granted or pending
-
- if( prev = !(latch->exclusive | latch->pending) )
-#ifdef unix
- __sync_fetch_and_add((ushort *)latch, Share);
-#else
- _InterlockedExchangeAdd16 ((ushort *)latch, Share);
-#endif
-
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
-#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
-#endif
- if( prev )
- return;
-#ifdef unix
- } while( sched_yield(), 1 );
-#else
- } while( SwitchToThread(), 1 );
-#endif
-}
-
-// wait for other read and write latches to relinquish
-
-void bt_spinwritelock(BtSpinLatch *latch)
-{
-ushort prev;
-
- do {
-#ifdef unix
- while( __sync_fetch_and_or((ushort *)latch, Mutex | Pending) & Mutex )
- sched_yield();
-#else
- while( _InterlockedOr16((ushort *)latch, Mutex | Pending) & Mutex )
- SwitchToThread();
-#endif
- if( prev = !(latch->share | latch->exclusive) )
-#ifdef unix
- __sync_fetch_and_or((ushort *)latch, Write);
-#else
- _InterlockedOr16((ushort *)latch, Write);
-#endif
-
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~(Mutex | Pending));
-#else
- _InterlockedAnd16((ushort *)latch, ~(Mutex | Pending));
-#endif
- if( prev )
- return;
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- } while( 1 );
-}
-
-// try to obtain write lock
-
-// return 1 if obtained,
-// 0 otherwise
-
-int bt_spinwritetry(BtSpinLatch *latch)
-{
-ushort prev;
-
-#ifdef unix
- if( prev = __sync_fetch_and_or((ushort *)latch, Mutex), prev & Mutex )
- return 0;
-#else
- if( prev = _InterlockedOr16((ushort *)latch, Mutex), prev & Mutex )
- return 0;
-#endif
- // take write access if all bits are clear
-
- if( !prev )
-#ifdef unix
- __sync_fetch_and_or ((ushort *)latch, Write);
-#else
- _InterlockedOr16((ushort *)latch, Write);
-#endif
-
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
-#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
-#endif
- return !prev;
-}
-
-// clear write mode
-
-void bt_spinreleasewrite(BtSpinLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Write);
-#else
- _InterlockedAnd16((ushort *)latch, ~Write);
-#endif
-}
-
-// decrement reader count
-
-void bt_spinreleaseread(BtSpinLatch *latch)
-{
-#ifdef unix
- __sync_fetch_and_add((ushort *)latch, -Share);
-#else
- _InterlockedExchangeAdd16 ((ushort *)latch, -Share);
-#endif
-}
-
-// link latch table entry into latch hash table
-
-void bt_latchlink (BtDb *bt, ushort hashidx, ushort victim, uid page_no)
-{
-BtLatchSet *set = bt->mgr->latchsets + victim;
-
- if( set->next = bt->mgr->latchmgr->table[hashidx].slot )
- bt->mgr->latchsets[set->next].prev = victim;
-
- bt->mgr->latchmgr->table[hashidx].slot = victim;
- set->page_no = page_no;
- set->hash = hashidx;
- set->prev = 0;
-}
-
-// find existing latchset or inspire new one
-// return with latchset pinned
-
-BtLatchSet *bt_bindlatch (BtDb *bt, uid page_no, int incr)
-{
-ushort hashidx = page_no % bt->mgr->latchmgr->latchhash;
-ushort slot, avail = 0, victim, idx;
-BtLatchSet *set;
-
- // obtain read lock on hash table entry
-
- bt_spinreadlock(bt->mgr->latchmgr->table[hashidx].latch);
-
- if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
- {
- set = bt->mgr->latchsets + slot;
- if( page_no == set->page_no )
- break;
- } while( slot = set->next );
-
- if( slot && incr ) {
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- }
-
- bt_spinreleaseread (bt->mgr->latchmgr->table[hashidx].latch);
-
- if( slot )
- return set;
-
- // try again, this time with write lock
-
- bt_spinwritelock(bt->mgr->latchmgr->table[hashidx].latch);
-
- if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
- {
- set = bt->mgr->latchsets + slot;
- if( page_no == set->page_no )
- break;
- if( !set->pin && !avail )
- avail = slot;
- } while( slot = set->next );
-
- // found our entry, or take over an unpinned one
-
- if( slot || (slot = avail) ) {
- set = bt->mgr->latchsets + slot;
- if( incr )
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- set->page_no = page_no;
- bt_spinreleasewrite(bt->mgr->latchmgr->table[hashidx].latch);
- return set;
- }
-
- // see if there are any unused entries
-#ifdef unix
- victim = __sync_fetch_and_add (&bt->mgr->latchmgr->latchdeployed, 1) + 1;
-#else
- victim = _InterlockedIncrement16 (&bt->mgr->latchmgr->latchdeployed);
-#endif
-
- if( victim < bt->mgr->latchmgr->latchtotal ) {
- set = bt->mgr->latchsets + victim;
- if( incr )
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- bt_latchlink (bt, hashidx, victim, page_no);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch);
- return set;
- }
-
-#ifdef unix
- victim = __sync_fetch_and_add (&bt->mgr->latchmgr->latchdeployed, -1);
-#else
- victim = _InterlockedDecrement16 (&bt->mgr->latchmgr->latchdeployed);
-#endif
- // find and reuse previous lock entry
-
- while( 1 ) {
-#ifdef unix
- victim = __sync_fetch_and_add(&bt->mgr->latchmgr->latchvictim, 1);
-#else
- victim = _InterlockedIncrement16 (&bt->mgr->latchmgr->latchvictim) - 1;
-#endif
- // we don't use slot zero
-
- if( victim %= bt->mgr->latchmgr->latchtotal )
- set = bt->mgr->latchsets + victim;
- else
- continue;
-
- // take control of our slot
- // from other threads
-
- if( set->pin || !bt_spinwritetry (set->busy) )
- continue;
-
- idx = set->hash;
-
- // try to get write lock on hash chain
- // skip entry if not obtained
- // or has outstanding locks
-
- if( !bt_spinwritetry (bt->mgr->latchmgr->table[idx].latch) ) {
- bt_spinreleasewrite (set->busy);
- continue;
- }
-
- if( set->pin ) {
- bt_spinreleasewrite (set->busy);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch);
- continue;
- }
-
- // unlink our available victim from its hash chain
-
- if( set->prev )
- bt->mgr->latchsets[set->prev].next = set->next;
- else
- bt->mgr->latchmgr->table[idx].slot = set->next;
-
- if( set->next )
- bt->mgr->latchsets[set->next].prev = set->prev;
-
- bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch);
-
- if( incr )
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
-
- bt_latchlink (bt, hashidx, victim, page_no);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch);
- bt_spinreleasewrite (set->busy);
- return set;
- }
-}
-
-void bt_mgrclose (BtMgr *mgr)
-{
-BtPool *pool;
-uint slot;
-
- // release mapped pages
- // note that slot zero is never used
-
- for( slot = 1; slot < mgr->poolmax; slot++ ) {
- pool = mgr->pool + slot;
- if( pool->slot )
-#ifdef unix
- munmap (pool->map, (mgr->poolmask+1) << mgr->page_bits);
-#else
- {
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
- }
-#endif
- }
-
-#ifdef unix
- close (mgr->idx);
- free (mgr->pool);
- free (mgr->hash);
- free (mgr->latch);
- free (mgr->pooladvise);
- free (mgr);
-#else
- FlushFileBuffers(mgr->idx);
- CloseHandle(mgr->idx);
- GlobalFree (mgr->pool);
- GlobalFree (mgr->hash);
- GlobalFree (mgr->latch);
- GlobalFree (mgr);
-#endif
-}
-
-// close and release memory
-
-void bt_close (BtDb *bt)
-{
-#ifdef unix
- if ( bt->mem )
- free (bt->mem);
-#else
- if ( bt->mem)
- VirtualFree (bt->mem, 0, MEM_RELEASE);
-#endif
- free (bt);
-}
-
-// open/create new btree buffer manager
-
-// call with file_name, BT_openmode, bits in page size (e.g. 16),
-// size of mapped page pool (e.g. 8192)
-
-BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolmax, uint segsize, uint hashsize)
-{
-uint lvl, attr, cacheblk, last, slot, idx;
-uint nlatchpage, latchhash;
-BtLatchMgr *latchmgr;
-off64_t size;
-uint amt[1];
-BtMgr* mgr;
-BtKey key;
-int flag;
-
-#ifndef unix
-SYSTEM_INFO sysinfo[1];
-#endif
-
- // determine sanity of page size and buffer pool
-
- if( bits > BT_maxbits )
- bits = BT_maxbits;
- else if( bits < BT_minbits )
- bits = BT_minbits;
-
- if( !poolmax )
- return NULL; // must have buffer pool
-
-#ifdef unix
- mgr = calloc (1, sizeof(BtMgr));
-
- mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
-
- if( mgr->idx == -1 )
- return free(mgr), NULL;
-
- cacheblk = 4096; // minimum mmap segment size for unix
-
-#else
- mgr = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtMgr));
- attr = FILE_ATTRIBUTE_NORMAL;
- mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
-
- if( mgr->idx == INVALID_HANDLE_VALUE )
- return GlobalFree(mgr), NULL;
-
- // normalize cacheblk to multiple of sysinfo->dwAllocationGranularity
- GetSystemInfo(sysinfo);
- cacheblk = sysinfo->dwAllocationGranularity;
-#endif
-
-#ifdef unix
- latchmgr = malloc (BT_maxpage);
- *amt = 0;
-
- // read minimum page size to get root info
-
- if( size = lseek (mgr->idx, 0L, 2) ) {
- if( pread(mgr->idx, latchmgr, BT_minpage, 0) == BT_minpage )
- bits = latchmgr->alloc->bits;
- else
- return free(mgr), free(latchmgr), NULL;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#else
- latchmgr = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
- size = GetFileSize(mgr->idx, amt);
-
- if( size || *amt ) {
- if( !ReadFile(mgr->idx, (char *)latchmgr, BT_minpage, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- bits = latchmgr->alloc->bits;
- } else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- mgr->page_size = 1 << bits;
- mgr->page_bits = bits;
-
- mgr->poolmax = poolmax;
- mgr->mode = mode;
-
- if( cacheblk < mgr->page_size )
- cacheblk = mgr->page_size;
-
- // mask for partial memmaps
-
- mgr->poolmask = (cacheblk >> bits) - 1;
-
- // see if requested size of pages per memmap is greater
-
- if( (1 << segsize) > mgr->poolmask )
- mgr->poolmask = (1 << segsize) - 1;
-
- mgr->seg_bits = 0;
-
- while( (1 << mgr->seg_bits) <= mgr->poolmask )
- mgr->seg_bits++;
-
- mgr->hashsize = hashsize;
-
-#ifdef unix
- mgr->pool = calloc (poolmax, sizeof(BtPool));
- mgr->hash = calloc (hashsize, sizeof(ushort));
- mgr->latch = calloc (hashsize, sizeof(BtSpinLatch));
- mgr->pooladvise = calloc (poolmax, (mgr->poolmask + 8) / 8);
-#else
- mgr->pool = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, poolmax * sizeof(BtPool));
- mgr->hash = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(ushort));
- mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtSpinLatch));
-#endif
-
- if( size || *amt )
- goto mgrlatch;
-
- // initialize an empty b-tree with latch page, root page, page of leaves
- // and page(s) of latches
-
- memset (latchmgr, 0, 1 << bits);
- nlatchpage = BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1;
- bt_putid(latchmgr->alloc->right, MIN_lvl+1+nlatchpage);
- latchmgr->alloc->bits = mgr->page_bits;
-
- latchmgr->nlatchpage = nlatchpage;
- latchmgr->latchtotal = nlatchpage * (mgr->page_size / sizeof(BtLatchSet));
-
- // initialize latch manager
-
- latchhash = (mgr->page_size - sizeof(BtLatchMgr)) / sizeof(BtHashEntry);
-
- // size of hash table = total number of latchsets
-
- if( latchhash > latchmgr->latchtotal )
- latchhash = latchmgr->latchtotal;
-
- latchmgr->latchhash = latchhash;
-
-#ifdef unix
- if( write (mgr->idx, latchmgr, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
-
- memset (latchmgr, 0, 1 << bits);
- latchmgr->alloc->bits = mgr->page_bits;
-
- for( lvl=MIN_lvl; lvl--; ) {
- slotptr(latchmgr->alloc, 1)->off = mgr->page_size - 3;
- bt_putid(slotptr(latchmgr->alloc, 1)->id, lvl ? MIN_lvl - lvl + 1 : 0); // next(lower) page number
- key = keyptr(latchmgr->alloc, 1);
- key->len = 2; // create stopper key
- key->key[0] = 0xff;
- key->key[1] = 0xff;
- latchmgr->alloc->min = mgr->page_size - 3;
- latchmgr->alloc->lvl = lvl;
- latchmgr->alloc->cnt = 1;
- latchmgr->alloc->act = 1;
-#ifdef unix
- if( write (mgr->idx, latchmgr, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#else
- if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
-
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- }
-
- // clear out latch manager locks
- // and rest of pages to round out segment
-
- memset(latchmgr, 0, mgr->page_size);
- last = MIN_lvl + 1;
-
- while( last <= ((MIN_lvl + 1 + nlatchpage) | mgr->poolmask) ) {
-#ifdef unix
- pwrite(mgr->idx, latchmgr, mgr->page_size, last << mgr->page_bits);
-#else
- SetFilePointer (mgr->idx, last << mgr->page_bits, NULL, FILE_BEGIN);
- if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
- return bt_mgrclose (mgr), NULL;
- if( *amt < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
-#endif
- last++;
- }
-
-mgrlatch:
-#ifdef unix
- flag = PROT_READ | PROT_WRITE;
- mgr->latchmgr = mmap (0, mgr->page_size, flag, MAP_SHARED, mgr->idx, ALLOC_page * mgr->page_size);
- if( mgr->latchmgr == MAP_FAILED )
- return bt_mgrclose (mgr), NULL;
- mgr->latchsets = (BtLatchSet *)mmap (0, mgr->latchmgr->nlatchpage * mgr->page_size, flag, MAP_SHARED, mgr->idx, LATCH_page * mgr->page_size);
- if( mgr->latchsets == MAP_FAILED )
- return bt_mgrclose (mgr), NULL;
-#else
- flag = PAGE_READWRITE;
- mgr->halloc = CreateFileMapping(mgr->idx, NULL, flag, 0, (BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1 + LATCH_page) * mgr->page_size, NULL);
- if( !mgr->halloc )
- return bt_mgrclose (mgr), NULL;
-
- flag = FILE_MAP_WRITE;
- mgr->latchmgr = MapViewOfFile(mgr->halloc, flag, 0, 0, (BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1 + LATCH_page) * mgr->page_size);
- if( !mgr->latchmgr )
- return GetLastError(), bt_mgrclose (mgr), NULL;
-
- mgr->latchsets = (void *)((char *)mgr->latchmgr + LATCH_page * mgr->page_size);
-#endif
-
-#ifdef unix
- free (latchmgr);
-#else
- VirtualFree (latchmgr, 0, MEM_RELEASE);
-#endif
- return mgr;
-}
-
-// open BTree access method
-// based on buffer manager
-
-BtDb *bt_open (BtMgr *mgr)
-{
-BtDb *bt = malloc (sizeof(*bt));
-
- memset (bt, 0, sizeof(*bt));
- bt->mgr = mgr;
-#ifdef unix
- bt->mem = malloc (3 *mgr->page_size);
-#else
- bt->mem = VirtualAlloc(NULL, 3 * mgr->page_size, MEM_COMMIT, PAGE_READWRITE);
-#endif
- bt->frame = (BtPage)bt->mem;
- bt->zero = (BtPage)(bt->mem + 1 * mgr->page_size);
- bt->cursor = (BtPage)(bt->mem + 2 * mgr->page_size);
- return bt;
-}
-
-// compare two keys, returning > 0, = 0, or < 0
-// as the comparison value
-
-int keycmp (BtKey key1, unsigned char *key2, uint len2)
-{
-uint len1 = key1->len;
-int ans;
-
- if( ans = memcmp (key1->key, key2, len1 > len2 ? len2 : len1) )
- return ans;
-
- if( len1 > len2 )
- return 1;
- if( len1 < len2 )
- return -1;
-
- return 0;
-}
-
-// Buffer Pool mgr
-
-// find segment in pool
-// must be called with hashslot idx locked
-// return NULL if not there
-// otherwise return node
-
-BtPool *bt_findpool(BtDb *bt, uid page_no, uint idx)
-{
-BtPool *pool;
-uint slot;
-
- // compute start of hash chain in pool
-
- if( slot = bt->mgr->hash[idx] )
- pool = bt->mgr->pool + slot;
- else
- return NULL;
-
- page_no &= ~bt->mgr->poolmask;
-
- while( pool->basepage != page_no )
- if( pool = pool->hashnext )
- continue;
- else
- return NULL;
-
- return pool;
-}
-
-// add segment to hash table
-
-void bt_linkhash(BtDb *bt, BtPool *pool, uid page_no, int idx)
-{
-BtPool *node;
-uint slot;
-
- pool->hashprev = pool->hashnext = NULL;
- pool->basepage = page_no & ~bt->mgr->poolmask;
- pool->lru = 1;
-
- if( slot = bt->mgr->hash[idx] ) {
- node = bt->mgr->pool + slot;
- pool->hashnext = node;
- node->hashprev = pool;
- }
-
- bt->mgr->hash[idx] = pool->slot;
-}
-
-// find best segment to evict from buffer pool
-
-BtPool *bt_findlru (BtDb *bt, uint hashslot)
-{
-unsigned long long int target = ~0LL;
-BtPool *pool = NULL, *node;
-
- if( !hashslot )
- return NULL;
-
- node = bt->mgr->pool + hashslot;
-
- // scan pool entries under hash table slot
-
- do {
- if( node->pin )
- continue;
- if( node->lru > target )
- continue;
- target = node->lru;
- pool = node;
- } while( node = node->hashnext );
-
- return pool;
-}
-
-// map new buffer pool segment to virtual memory
-
-BTERR bt_mapsegment(BtDb *bt, BtPool *pool, uid page_no)
-{
-off64_t off = (page_no & ~bt->mgr->poolmask) << bt->mgr->page_bits;
-off64_t limit = off + ((bt->mgr->poolmask+1) << bt->mgr->page_bits);
-int flag;
-
-#ifdef unix
- flag = PROT_READ | ( bt->mgr->mode == BT_ro ? 0 : PROT_WRITE );
- pool->map = mmap (0, (bt->mgr->poolmask+1) << bt->mgr->page_bits, flag, MAP_SHARED, bt->mgr->idx, off);
- if( pool->map == MAP_FAILED )
- return bt->err = BTERR_map;
- // clear out madvise issued bits
- memset (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8) / 8), 0, (bt->mgr->poolmask + 8)/8);
-#else
- flag = ( bt->mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
- pool->hmap = CreateFileMapping(bt->mgr->idx, NULL, flag, (DWORD)(limit >> 32), (DWORD)limit, NULL);
- if( !pool->hmap )
- return bt->err = BTERR_map;
-
- flag = ( bt->mgr->mode == BT_ro ? FILE_MAP_READ : FILE_MAP_WRITE );
- pool->map = MapViewOfFile(pool->hmap, flag, (DWORD)(off >> 32), (DWORD)off, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
- if( !pool->map )
- return bt->err = BTERR_map;
-#endif
- return bt->err = 0;
-}
-
-// find or place requested page in segment-pool
-// return pool table entry, incrementing pin
-
-BtPool *bt_pinpage(BtDb *bt, uid page_no)
-{
-BtPool *pool, *node, *next;
-uint slot, idx, victim;
-BtLatchSet *set;
-
- // lock hash table chain
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_spinreadlock (&bt->mgr->latch[idx]);
-
- // look up in hash table
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleaseread (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // upgrade to write lock
-
- bt_spinreleaseread (&bt->mgr->latch[idx]);
- bt_spinwritelock (&bt->mgr->latch[idx]);
-
- // try to find page in pool with write lock
-
- if( pool = bt_findpool(bt, page_no, idx) ) {
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
- pool->lru++;
- return pool;
- }
-
- // allocate a new pool node
- // and add to hash table
-
-#ifdef unix
- slot = __sync_fetch_and_add(&bt->mgr->poolcnt, 1);
-#else
- slot = _InterlockedIncrement16 (&bt->mgr->poolcnt) - 1;
-#endif
-
- if( ++slot < bt->mgr->poolmax ) {
- pool = bt->mgr->pool + slot;
- pool->slot = slot;
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-
- // pool table is full
- // find best pool entry to evict
-
-#ifdef unix
- __sync_fetch_and_add(&bt->mgr->poolcnt, -1);
-#else
- _InterlockedDecrement16 (&bt->mgr->poolcnt);
-#endif
-
- while( 1 ) {
-#ifdef unix
- victim = __sync_fetch_and_add(&bt->mgr->evicted, 1);
-#else
- victim = _InterlockedIncrement16 (&bt->mgr->evicted) - 1;
-#endif
- victim %= bt->mgr->hashsize;
-
- // try to get write lock
- // skip entry if not obtained
-
- if( !bt_spinwritetry (&bt->mgr->latch[victim]) )
- continue;
-
- // if cache entry is empty
- // or no slots are unpinned
- // skip this entry
-
- if( !(pool = bt_findlru(bt, bt->mgr->hash[victim])) ) {
- bt_spinreleasewrite (&bt->mgr->latch[victim]);
- continue;
- }
-
- // unlink victim pool node from hash table
-
- if( node = pool->hashprev )
- node->hashnext = pool->hashnext;
- else if( node = pool->hashnext )
- bt->mgr->hash[victim] = node->slot;
- else
- bt->mgr->hash[victim] = 0;
-
- if( node = pool->hashnext )
- node->hashprev = pool->hashprev;
-
- bt_spinreleasewrite (&bt->mgr->latch[victim]);
-
- // remove old file mapping
-#ifdef unix
- munmap (pool->map, (bt->mgr->poolmask+1) << bt->mgr->page_bits);
-#else
- FlushViewOfFile(pool->map, 0);
- UnmapViewOfFile(pool->map);
- CloseHandle(pool->hmap);
-#endif
- pool->map = NULL;
-
- // create new pool mapping
- // and link into hash table
-
- if( bt_mapsegment(bt, pool, page_no) )
- return NULL;
-
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement16 (&pool->pin);
-#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
- return pool;
- }
-}
-
-// place write, read, or parent lock on requested page_no.
-// pin to buffer pool and return latchset pointer
-
-BtLatchSet *bt_lockpage(BtDb *bt, uid page_no, BtLock mode, BtPage *pageptr, BtLatchSet *set)
-{
-BtPool *pool;
-uint subpage;
-BtPage page;
-
- // find/create maping in pool table
- // and pin our pool slot
-
- if( pool = bt_pinpage(bt, page_no) )
- subpage = (uint)(page_no & bt->mgr->poolmask); // page within mapping
- else
- return NULL;
-
- if( set )
-#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
-#else
- _InterlockedIncrement16 (&set->pin);
-#endif
- else if( !(set = bt_bindlatch (bt, page_no, 1)) )
- return NULL;
-
- page = (BtPage)(pool->map + (subpage << bt->mgr->page_bits));
-
-#ifdef unix
- {
- uint idx = subpage / 8;
- uint bit = subpage % 8;
-
- if( mode == BtLockRead || mode == BtLockWrite )
- if( ~((bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] >> bit) & 1 ) {
- madvise (page, bt->mgr->page_size, MADV_WILLNEED);
- (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] |= 1 << bit;
- }
- }
-#endif
-
- switch( mode ) {
- case BtLockRead:
- bt_spinreadlock (set->readwr);
- break;
- case BtLockWrite:
- bt_spinwritelock (set->readwr);
- break;
- case BtLockAccess:
- bt_spinreadlock (set->access);
- break;
- case BtLockDelete:
- bt_spinwritelock (set->access);
- break;
- case BtLockParent:
- bt_spinwritelock (set->parent);
- break;
- case BtLockPin:
- break;
- default:
- return bt->err = BTERR_lock, NULL;
- }
-
- if( pageptr )
- *pageptr = page;
-
- return set;
-}
-
-// remove write, read, or parent lock on requested page_no.
-
-BTERR bt_unlockpage(BtDb *bt, uid page_no, BtLock mode, BtLatchSet *set)
-{
-BtPool *pool;
-uint idx;
-
- // since page is pinned
- // it should still be in the buffer pool
- // and is in no danger of being a victim for reuse
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_spinreadlock (&bt->mgr->latch[idx]);
-
- if( !(pool = bt_findpool(bt, page_no, idx)) )
- return bt->err = BTERR_hash;
-
- bt_spinreleaseread (&bt->mgr->latch[idx]);
-
- switch( mode ) {
- case BtLockRead:
- bt_spinreleaseread (set->readwr);
- break;
- case BtLockWrite:
- bt_spinreleasewrite (set->readwr);
- break;
- case BtLockAccess:
- bt_spinreleaseread (set->access);
- break;
- case BtLockDelete:
- bt_spinreleasewrite (set->access);
- break;
- case BtLockParent:
- bt_spinreleasewrite (set->parent);
- break;
- case BtLockPin:
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, -1);
- __sync_fetch_and_add (&set->pin, -1);
-#else
- _InterlockedDecrement16 (&pool->pin);
- _InterlockedDecrement16 (&set->pin);
-#endif
- return bt->err = 0;
-}
-
-// deallocate a deleted page
-// place on free chain out of allocator page
-// fence key must already be removed from parent
-
-BTERR bt_freepage(BtDb *bt, uid page_no, BtLatchSet *set)
-{
- // obtain delete lock on deleted page
-
- if( !bt_lockpage(bt, page_no, BtLockDelete, NULL, set) )
- return bt->err;
-
- // obtain write lock on deleted page
-
- if( !bt_lockpage(bt, page_no, BtLockWrite, &bt->temp, set) )
- return bt->err;
-
- // lock allocation page
-
- bt_spinwritelock(bt->mgr->latchmgr->lock);
-
- // store free chain in allocation page second right
- bt_putid(bt->temp->right, bt_getid(bt->mgr->latchmgr->alloc[1].right));
- bt_putid(bt->mgr->latchmgr->alloc[1].right, page_no);
-
- // unlock page zero
-
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
-
- // remove write lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockWrite, set) )
- return bt->err;
-
- // remove delete lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockDelete, set) )
- return bt->err;
-
- return 0;
-}
-
-// allocate a new page and write page into it
-
-uid bt_newpage(BtDb *bt, BtPage page)
-{
-BtLatchSet *set;
-uid new_page;
-BtPage pmap;
-int reuse;
-
- // lock allocation page
-
- bt_spinwritelock(bt->mgr->latchmgr->lock);
-
- // use empty chain first
- // else allocate empty page
-
- if( new_page = bt_getid(bt->mgr->latchmgr->alloc[1].right) ) {
- if( !(set = bt_lockpage (bt, new_page, BtLockWrite, &bt->temp, NULL)) )
- return 0;
- bt_putid(bt->mgr->latchmgr->alloc[1].right, bt_getid(bt->temp->right));
- if( bt_unlockpage (bt, new_page, BtLockWrite, set) )
- return 0;
- reuse = 1;
- } else {
- new_page = bt_getid(bt->mgr->latchmgr->alloc->right);
- bt_putid(bt->mgr->latchmgr->alloc->right, new_page+1);
- reuse = 0;
- }
-#ifdef unix
- if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
-
- // if writing first page of pool block, zero last page in the block
-
- if ( !reuse && bt->mgr->poolmask > 0 && (new_page & bt->mgr->poolmask) == 0 )
- {
- // use zero buffer to write zeros
- memset(bt->zero, 0, bt->mgr->page_size);
- if ( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->poolmask) << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
- }
-#else
- // bring new page into pool and copy page.
- // this will extend the file into the new pages.
-
- if( !(set = bt_lockpage(bt, new_page, BtLockWrite, &pmap, NULL)) )
- return 0;
-
- memcpy(pmap, page, bt->mgr->page_size);
-
- if( bt_unlockpage (bt, new_page, BtLockWrite, set) )
- return 0;
-#endif
- // unlock allocation latch and return new page no
-
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
- return new_page;
-}
-
-// find slot in page for given key at a given level
-
-int bt_findslot (BtDb *bt, unsigned char *key, uint len)
-{
-uint diff, higher = bt->page->cnt, low = 1, slot;
-
- // low is the lowest candidate, higher is already
- // tested as .ge. the given key, loop ends when they meet
-
- while( diff = higher - low ) {
- slot = low + ( diff >> 1 );
- if( keycmp (keyptr(bt->page, slot), key, len) < 0 )
- low = slot + 1;
- else
- higher = slot;
- }
-
- return higher;
-}
-
-// find and load page at given level for given key
-// leave page rd or wr locked as requested
-
-int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, BtLock lock)
-{
-uid page_no = ROOT_page, prevpage = 0;
-BtLatchSet *set, *prevset;
-uint drill = 0xff, slot;
-uint mode, prevmode;
-
- bt->set = NULL;
-
- // start at root of btree and drill down
-
- do {
- // determine lock mode of drill level
- mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead;
-
- bt->page_no = page_no;
-
- // obtain access lock using lock chaining with Access mode
-
- if( page_no > ROOT_page )
- if( !(bt->set = bt_lockpage(bt, page_no, BtLockAccess, NULL, NULL)) )
- return 0;
-
- // now unlock our (possibly foster) parent
-
- if( prevpage )
- if( bt_unlockpage(bt, prevpage, prevmode, prevset) )
- return 0;
- else
- prevpage = 0;
-
- // obtain read lock using lock chaining
- // and pin page contents
-
- if( !(bt->set = bt_lockpage(bt, page_no, mode, &bt->page, bt->set)) )
- return 0;
-
- if( page_no > ROOT_page )
- if( bt_unlockpage(bt, page_no, BtLockAccess, bt->set) )
- return 0;
-
- // re-read and re-lock root after determining actual level of root
-
- if( bt->page_no == ROOT_page )
- if( bt->page->lvl != drill) {
- drill = bt->page->lvl;
-
- if( lock == BtLockWrite && drill == lvl )
- if( bt_unlockpage(bt, page_no, mode, bt->set) )
- return 0;
- else
- continue;
- }
-
- prevpage = bt->page_no;
- prevset = bt->set;
- prevmode = mode;
-
- // if page is being deleted,
- // move back to preceeding page
-
- if( bt->page->kill ) {
- page_no = bt_getid (bt->page->right);
- continue;
- }
-
- // find key on page at this level
- // and descend to requested level
-
- slot = bt_findslot (bt, key, len);
-
- // is this slot a foster child?
-
- if( slot <= bt->page->cnt - bt->page->foster )
- if( drill == lvl )
- return slot;
-
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
- continue;
- else
- goto slideright;
-
- if( slot <= bt->page->cnt - bt->page->foster )
- drill--;
-
- // continue down / right using overlapping locks
- // to protect pages being killed or split.
-
- page_no = bt_getid(slotptr(bt->page, slot)->id);
- continue;
-
-slideright:
- page_no = bt_getid(bt->page->right);
-
- } while( page_no );
-
- // return error on end of chain
-
- bt->err = BTERR_struct;
- return 0; // return error
-}
-
-// find and delete key on page by marking delete flag bit
-// when page becomes empty, delete it from the btree
-
-BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl)
-{
-unsigned char leftkey[256], rightkey[256];
-BtLatchSet *rset, *set;
-uid page_no, right;
-uint slot, tod;
-BtKey ptr;
-
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // if key is found delete it, otherwise ignore request
-
- if( !keycmp (ptr, key, len) )
- if( slotptr(bt->page, slot)->dead == 0 ) {
- slotptr(bt->page,slot)->dead = 1;
- if( slot < bt->page->cnt )
- bt->page->dirty = 1;
- bt->page->act--;
- }
-
- // return if page is not empty, or it has no right sibling
-
- right = bt_getid(bt->page->right);
- page_no = bt->page_no;
- set = bt->set;
-
- if( !right || bt->page->act )
- return bt_unlockpage(bt, page_no, BtLockWrite, set);
-
- // obtain Parent lock over write lock
-
- if( !bt_lockpage(bt, page_no, BtLockParent, NULL, set) )
- return bt->err;
-
- // cache copy of key to delete
-
- ptr = keyptr(bt->page, bt->page->cnt);
- memcpy(leftkey, ptr, ptr->len + 1);
-
- // lock and map right page
-
- if( !(rset = bt_lockpage(bt, right, BtLockWrite, &bt->temp, NULL)) )
- return bt->err;
-
- // pull contents of next page into current empty page
- memcpy (bt->page, bt->temp, bt->mgr->page_size);
-
- // cache copy of key to update
- ptr = keyptr(bt->temp, bt->temp->cnt);
- memcpy(rightkey, ptr, ptr->len + 1);
-
- // Mark right page as deleted and point it to left page
- // until we can post updates at higher level.
-
- bt_putid(bt->temp->right, page_no);
- bt->temp->kill = 1;
- bt->temp->cnt = 0;
-
- if( bt_unlockpage(bt, right, BtLockWrite, rset) )
- return bt->err;
- if( bt_unlockpage(bt, page_no, BtLockWrite, set) )
- return bt->err;
-
- // delete old lower key to consolidated node
-
- if( bt_deletekey (bt, leftkey + 1, *leftkey, lvl + 1) )
- return bt->err;
-
- // redirect higher key directly to consolidated node
-
- if( slot = bt_loadpage (bt, rightkey+1, *rightkey, lvl+1, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // since key already exists, update id
-
- if( keycmp (ptr, rightkey+1, *rightkey) )
- return bt->err = BTERR_struct;
-
- slotptr(bt->page, slot)->dead = 0;
- bt_putid(slotptr(bt->page,slot)->id, page_no);
-
- if( bt_unlockpage(bt, bt->page_no, BtLockWrite, bt->set) )
- return bt->err;
-
- // obtain write lock and
- // add right block to free chain
-
- if( bt_freepage (bt, right, rset) )
- return bt->err;
-
- // remove ParentModify lock
-
- if( bt_unlockpage(bt, page_no, BtLockParent, set) )
- return bt->err;
-
- return 0;
-}
-
-// find key in leaf level and return row-id
-
-uid bt_findkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-BtKey ptr;
-uid id;
-
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- ptr = keyptr(bt->page, slot);
- else
- return 0;
-
- // if key exists, return row-id
- // otherwise return 0
-
- if( ptr->len == len && !memcmp (ptr->key, key, len) )
- id = bt_getid(slotptr(bt->page,slot)->id);
- else
- id = 0;
-
- if( bt_unlockpage (bt, bt->page_no, BtLockRead, bt->set) )
- return 0;
-
- return id;
-}
-
-// check page for space available,
-// clean if necessary and return
-// 0 - page needs splitting
-// 1 - go ahead
-
-uint bt_cleanpage(BtDb *bt, uint amt)
-{
-uint nxt = bt->mgr->page_size;
-BtPage page = bt->page;
-uint cnt = 0, idx = 0;
-uint max = page->cnt;
-BtKey key;
-
- if( page->min >= (max+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- // skip cleanup if nothing to reclaim
-
- if( !page->dirty )
- return 0;
-
- memcpy (bt->frame, page, bt->mgr->page_size);
-
- // skip page info and set rest of page to zero
-
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- page->dirty = 0;
- page->act = 0;
-
- // try cleaning up page first
-
- while( cnt++ < max ) {
- // always leave fence key and foster children in list
- if( cnt < max - page->foster && slotptr(bt->frame,cnt)->dead )
- continue;
-
- // copy key
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
-
- // copy slot
- memcpy(slotptr(page, ++idx)->id, slotptr(bt->frame, cnt)->id, BtId);
- if( !(slotptr(page, idx)->dead = slotptr(bt->frame, cnt)->dead) )
- page->act++;
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // see if page has enough space now, or does it need splitting?
-
- if( page->min >= (idx+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
-
- return 0;
-}
-
-// add key to current page
-// page must already be writelocked
-
-void bt_addkeytopage (BtDb *bt, uint slot, unsigned char *key, uint len, uid id, uint tod)
-{
-BtPage page = bt->page;
-uint idx;
-
- // calculate next available slot and copy key into page
-
- page->min -= len + 1;
- ((unsigned char *)page)[page->min] = len;
- memcpy ((unsigned char *)page + page->min +1, key, len );
-
- for( idx = slot; idx < page->cnt; idx++ )
- if( slotptr(page, idx)->dead )
- break;
-
- // now insert key into array before slot
- // preserving the fence slot
-
- if( idx == page->cnt )
- idx++, page->cnt++;
-
- page->act++;
-
- while( idx > slot )
- *slotptr(page, idx) = *slotptr(page, idx -1), idx--;
-
- bt_putid(slotptr(page,slot)->id, id);
- slotptr(page, slot)->off = page->min;
- slotptr(page, slot)->tod = tod;
- slotptr(page, slot)->dead = 0;
-}
-
-// split the root and raise the height of the btree
-// call with current page locked and page no of foster child
-// return with current page (root) unlocked
-
-BTERR bt_splitroot(BtDb *bt, uid right)
-{
-uint nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-BtPage root = bt->page;
-uid new_page;
-BtKey key;
-
- // Obtain an empty page to use, and copy the left page
- // contents into it from the root. Strip foster child key.
- // (it's the stopper key)
-
- root->act--;
- root->cnt--;
- root->foster--;
-
- // Save left fence key.
-
- key = keyptr(root, root->cnt);
- memcpy (fencekey, key, key->len + 1);
-
- // copy the lower keys into a new left page
-
- if( !(new_page = bt_newpage(bt, root)) )
- return bt->err;
-
- // preserve the page info at the bottom
- // and set rest of the root to zero
-
- memset (root+1, 0, bt->mgr->page_size - sizeof(*root));
-
- // insert left fence key on empty newroot page
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 1)->id, new_page);
- slotptr(root, 1)->off = nxt;
-
- // insert stopper key on newroot page
- // and increase the root height
-
- nxt -= 3;
- fencekey[0] = 2;
- fencekey[1] = 0xff;
- fencekey[2] = 0xff;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 2)->id, right);
- slotptr(root, 2)->off = nxt;
-
- bt_putid(root->right, 0);
- root->min = nxt; // reset lowest used offset and key count
- root->cnt = 2;
- root->act = 2;
- root->lvl++;
-
- // release root (bt->page)
-
- return bt_unlockpage(bt, ROOT_page, BtLockWrite, bt->set);
-}
-
-// split already locked full node
-// in current page variables
-// return unlocked.
-
-BTERR bt_splitpage (BtDb *bt)
-{
-uint slot, cnt, idx, max, nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-uid page_no = bt->page_no;
-BtLatchSet *set = bt->set;
-BtPage page = bt->page;
-uint tod = time(NULL);
-uint lvl = page->lvl;
-uid new_page, right;
-BtKey key;
-
- // initialize frame buffer
-
- memset (bt->frame, 0, bt->mgr->page_size);
- max = page->cnt - page->foster;
- tod = (uint)time(NULL);
- cnt = max / 2;
- idx = 0;
-
- // split higher half of keys to bt->frame
- // leaving foster children in the left node.
-
- while( cnt++ < max ) {
- key = keyptr(page, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)bt->frame + nxt, key, key->len + 1);
- memcpy(slotptr(bt->frame,++idx)->id, slotptr(page,cnt)->id, BtId);
- slotptr(bt->frame, idx)->tod = slotptr(page, cnt)->tod;
- slotptr(bt->frame, idx)->off = nxt;
- bt->frame->act++;
- }
-
- // transfer right link node
-
- if( page_no > ROOT_page ) {
- right = bt_getid (page->right);
- bt_putid(bt->frame->right, right);
- }
-
- bt->frame->bits = bt->mgr->page_bits;
- bt->frame->min = nxt;
- bt->frame->cnt = idx;
- bt->frame->lvl = lvl;
-
- // get new free page and write frame to it.
-
- if( !(new_page = bt_newpage(bt, bt->frame)) )
- return bt->err;
-
- // remember fence key for new page to add
- // as foster child
-
- key = keyptr(bt->frame, idx);
- memcpy (fencekey, key, key->len + 1);
-
- // update lower keys and foster children to continue in old page
-
- memcpy (bt->frame, page, bt->mgr->page_size);
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
- nxt = bt->mgr->page_size;
- page->act = 0;
- cnt = 0;
- idx = 0;
-
- // assemble page of smaller keys
- // to remain in the old page
-
- while( cnt++ < max / 2 ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- // insert new foster child at beginning of the current foster children
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)page + nxt, fencekey, *fencekey + 1);
- bt_putid (slotptr(page,++idx)->id, new_page);
- slotptr(page, idx)->tod = tod;
- slotptr(page, idx)->off = nxt;
- page->foster++;
- page->act++;
-
- // continue with old foster child keys if any
-
- cnt = bt->frame->cnt - bt->frame->foster;
-
- while( cnt++ < bt->frame->cnt ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
- }
-
- page->min = nxt;
- page->cnt = idx;
-
- // link new right page
-
- bt_putid (page->right, new_page);
-
- // if current page is the root page, split it
-
- if( page_no == ROOT_page )
- return bt_splitroot (bt, new_page);
-
- // keep our latch set
- // release wr lock on our page
-
- if( !bt_lockpage (bt, page_no, BtLockPin, NULL, set) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockWrite, set) )
- return bt->err;
-
- // obtain ParentModification lock for current page
- // to fix fence key and highest foster child on page
-
- if( !bt_lockpage (bt, page_no, BtLockParent, NULL, set) )
- return bt->err;
-
- // get our highest foster child key to find in parent node
-
- if( !bt_lockpage (bt, page_no, BtLockRead, &page, set) )
- return bt->err;
-
- key = keyptr(page, page->cnt);
- memcpy (fencekey, key, key->len+1);
-
- if( bt_unlockpage (bt, page_no, BtLockRead, set) )
- return bt->err;
-
- // update our parent
-try_again:
-
- do {
- slot = bt_loadpage (bt, fencekey + 1, *fencekey, lvl + 1, BtLockWrite);
-
- if( !slot )
- return bt->err;
-
- // check if parent page has enough space for any possible key
-
- if( bt_cleanpage (bt, 256) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- } while( 1 );
-
- // see if we are still a foster child from another node
-
- if( bt_getid (slotptr(bt->page, slot)->id) != page_no ) {
- if( bt_unlockpage (bt, bt->page_no, BtLockWrite, bt->set) )
- return bt->err;
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- goto try_again;
- }
-
- // wait until readers from parent get their locks
- // on our page
-
- if( !bt_lockpage (bt, page_no, BtLockDelete, NULL, set) )
- return bt->err;
-
- // lock our page for writing
-
- if( !bt_lockpage (bt, page_no, BtLockWrite, &page, set) )
- return bt->err;
-
- // switch parent fence key to foster child
-
- if( slotptr(page, page->cnt)->dead )
- slotptr(bt->page, slot)->dead = 1;
- else
- bt_putid (slotptr(bt->page, slot)->id, bt_getid(slotptr(page, page->cnt)->id));
-
- // remove highest foster child from our page
-
- page->cnt--;
- page->act--;
- page->foster--;
- page->dirty = 1;
- key = keyptr(page, page->cnt);
-
- // add our new fence key for foster child to our parent
-
- bt_addkeytopage (bt, slot, key->key, key->len, page_no, tod);
-
- if( bt_unlockpage (bt, bt->page_no, BtLockWrite, bt->set) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockDelete, set) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockWrite, set) )
- return bt->err;
-
- if( bt_unlockpage (bt, page_no, BtLockParent, set) )
- return bt->err;
-
- // release extra latch pin
-
- return bt_unlockpage (bt, page_no, BtLockPin, set);
-}
-
-// Insert new key into the btree at leaf level.
-
-BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod)
-{
-uint slot, idx;
-BtPage page;
-BtKey ptr;
-
- while( 1 ) {
- if( slot = bt_loadpage (bt, key, len, 0, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- {
- if ( !bt->err )
- bt->err = BTERR_ovflw;
- return bt->err;
- }
-
- // if key already exists, update id and return
-
- page = bt->page;
-
- if( !keycmp (ptr, key, len) ) {
- slotptr(page, slot)->dead = 0;
- slotptr(page, slot)->tod = tod;
- bt_putid(slotptr(page,slot)->id, id);
- return bt_unlockpage(bt, bt->page_no, BtLockWrite, bt->set);
- }
-
- // check if page has enough space
-
- if( bt_cleanpage (bt, len) )
- break;
-
- if( bt_splitpage (bt) )
- return bt->err;
- }
-
- bt_addkeytopage (bt, slot, key, len, id, tod);
-
- return bt_unlockpage (bt, bt->page_no, BtLockWrite, bt->set);
-}
-
-// cache page of keys into cursor and return starting slot for given key
-
-uint bt_startkey (BtDb *bt, unsigned char *key, uint len)
-{
-uint slot;
-
- // cache page for retrieval
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- memcpy (bt->cursor, bt->page, bt->mgr->page_size);
- bt->cursor_page = bt->page_no;
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead, bt->set) )
- return 0;
-
- return slot;
-}
-
-// return next slot for cursor page
-// or slide cursor right into next page
-
-uint bt_nextkey (BtDb *bt, uint slot)
-{
-BtLatchSet *rset;
-BtPage page;
-uid right;
-
- do {
- right = bt_getid(bt->cursor->right);
- while( slot++ < bt->cursor->cnt - bt->cursor->foster )
- if( slotptr(bt->cursor,slot)->dead )
- continue;
- else if( right || (slot < bt->cursor->cnt - bt->cursor->foster) )
- return slot;
- else
- break;
-
- if( !right )
- break;
-
- bt->cursor_page = right;
-
- if( !(bt->set = bt_lockpage(bt, right, BtLockRead, &page, NULL)) )
- return 0;
-
- memcpy (bt->cursor, page, bt->mgr->page_size);
-
- if ( bt_unlockpage(bt, right, BtLockRead, bt->set) )
- return 0;
-
- slot = 0;
- } while( 1 );
-
- return bt->err = 0;
-}
-
-BtKey bt_key(BtDb *bt, uint slot)
-{
- return keyptr(bt->cursor, slot);
-}
-
-uid bt_uid(BtDb *bt, uint slot)
-{
- return bt_getid(slotptr(bt->cursor,slot)->id);
-}
-
-uint bt_tod(BtDb *bt, uint slot)
-{
- return slotptr(bt->cursor,slot)->tod;
-}
-
-
-#ifdef STANDALONE
-
-typedef struct {
- char type, idx;
- char *infile;
- BtMgr *mgr;
- int num;
-} ThreadArg;
-
-// standalone program to index file of keys
-// then list them onto std-out
-
-#ifdef unix
-void *index_file (void *arg)
-#else
-uint __stdcall index_file (void *arg)
-#endif
-{
-int line = 0, found = 0, cnt = 0;
-uid next, page_no = LEAF_page; // start on first page of leaves
-unsigned char key[256];
-ThreadArg *args = arg;
-int ch, len = 0, slot;
-time_t tod[1];
-BtPage page;
-BtKey ptr;
-BtDb *bt;
-FILE *in;
-
- bt = bt_open (args->mgr);
- time (tod);
-
- switch(args->type | 0x20)
- {
- case 'w':
- fprintf(stderr, "started indexing for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
-
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_insertkey (bt, key, len, line, *tod) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys\n", args->infile, line);
- break;
-
- case 'd':
- fprintf(stderr, "started deleting keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_deletekey (bt, key, len, 0) )
- fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for keys, %d \n", args->infile, line);
- break;
-
- case 'f':
- fprintf(stderr, "started finding keys for %s\n", args->infile);
- if( in = fopen (args->infile, "rb") )
- while( ch = getc(in), ch != EOF )
- if( ch == '\n' )
- {
- line++;
- if( args->num == 1 )
- sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
-
- else if( args->num )
- sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
-
- if( bt_findkey (bt, key, len) )
- found++;
- else if( bt->err )
- fprintf(stderr, "Error %d Syserr %d Line: %d\n", bt->err, errno, line), exit(0);
- len = 0;
- }
- else if( len < 255 )
- key[len++] = ch;
- fprintf(stderr, "finished %s for %d keys, found %d\n", args->infile, line, found);
- break;
-
- case 's':
- len = key[0] = 0;
-
- fprintf(stderr, "started reading\n");
-
- if( slot = bt_startkey (bt, key, len) )
- slot--;
- else
- fprintf(stderr, "Error %d in StartKey. Syserror: %d\n", bt->err, errno), exit(0);
-
- while( slot = bt_nextkey (bt, slot) ) {
- ptr = bt_key(bt, slot);
- fwrite (ptr->key, ptr->len, 1, stdout);
- fputc ('\n', stdout);
- }
-
- break;
-
- case 'c':
- fprintf(stderr, "started reading\n");
-
- do {
- bt->set = bt_lockpage (bt, page_no, BtLockRead, &page, NULL);
- cnt += page->act;
- next = bt_getid (page->right);
- bt_unlockpage (bt, page_no, BtLockRead, bt->set);
- } while( page_no = next );
-
- cnt--; // remove stopper key
- fprintf(stderr, " Total keys read %d\n", cnt);
- break;
- }
-
- bt_close (bt);
-#ifdef unix
- return NULL;
-#else
- return 0;
-#endif
-}
-
-typedef struct timeval timer;
-
-int main (int argc, char **argv)
-{
-int idx, cnt, len, slot, err;
-int segsize, bits = 16;
-#ifdef unix
-pthread_t *threads;
-timer start, stop;
-#else
-time_t start[1], stop[1];
-HANDLE *threads;
-#endif
-double real_time;
-ThreadArg *args;
-uint poolsize = 0;
-int num = 0;
-char key[1];
-BtMgr *mgr;
-BtKey ptr;
-BtDb *bt;
-
- if( argc < 3 ) {
- fprintf (stderr, "Usage: %s idx_file Read/Write/Scan/Delete/Find [page_bits mapped_segments seg_bits line_numbers src_file1 src_file2 ... ]\n", argv[0]);
- fprintf (stderr, " where page_bits is the page size in bits\n");
- fprintf (stderr, " mapped_segments is the number of mmap segments in buffer pool\n");
- fprintf (stderr, " seg_bits is the size of individual segments in buffer pool in pages in bits\n");
- fprintf (stderr, " line_numbers = 1 to append line numbers to keys\n");
- fprintf (stderr, " src_file1 thru src_filen are files of keys separated by newline\n");
- exit(0);
- }
-
-#ifdef unix
- gettimeofday(&start, NULL);
-#else
- time(start);
-#endif
-
- if( argc > 3 )
- bits = atoi(argv[3]);
-
- if( argc > 4 )
- poolsize = atoi(argv[4]);
-
- if( !poolsize )
- fprintf (stderr, "Warning: no mapped_pool\n");
-
- if( poolsize > 65535 )
- fprintf (stderr, "Warning: mapped_pool > 65535 segments\n");
-
- if( argc > 5 )
- segsize = atoi(argv[5]);
- else
- segsize = 4; // 16 pages per mmap segment
-
- if( argc > 6 )
- num = atoi(argv[6]);
-
- cnt = argc - 7;
-#ifdef unix
- threads = malloc (cnt * sizeof(pthread_t));
-#else
- threads = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, cnt * sizeof(HANDLE));
-#endif
- args = malloc (cnt * sizeof(ThreadArg));
-
- mgr = bt_mgr ((argv[1]), BT_rw, bits, poolsize, segsize, poolsize / 8);
-
- if( !mgr ) {
- fprintf(stderr, "Index Open Error %s\n", argv[1]);
- exit (1);
- }
-
- // fire off threads
-
- for( idx = 0; idx < cnt; idx++ ) {
- args[idx].infile = argv[idx + 7];
- args[idx].type = argv[2][0];
- args[idx].mgr = mgr;
- args[idx].num = num;
- args[idx].idx = idx;
-#ifdef unix
- if( err = pthread_create (threads + idx, NULL, index_file, args + idx) )
- fprintf(stderr, "Error creating thread %d\n", err);
-#else
- threads[idx] = (HANDLE)_beginthreadex(NULL, 65536, index_file, args + idx, 0, NULL);
-#endif
- }
-
- // wait for termination
-
-#ifdef unix
- for( idx = 0; idx < cnt; idx++ )
- pthread_join (threads[idx], NULL);
- gettimeofday(&stop, NULL);
- real_time = 1000.0 * ( stop.tv_sec - start.tv_sec ) + 0.001 * (stop.tv_usec - start.tv_usec );
-#else
- WaitForMultipleObjects (cnt, threads, TRUE, INFINITE);
-
- for( idx = 0; idx < cnt; idx++ )
- CloseHandle(threads[idx]);
-
- time (stop);
- real_time = 1000 * (*stop - *start);
-#endif
- fprintf(stderr, " Time to complete: %.2f seconds\n", real_time/1000);
- bt_mgrclose (mgr);
-}
-
-#endif //STANDALONE
-// foster btree version f2
-// 18 JAN 2014
+// btree version threads2j linux futex concurrency version
+// 24 JAN 2014
// author: karl malbrain, malbrain@cal.berkeley.edu
#ifdef linux
#define _GNU_SOURCE
+#include <linux/futex.h>
+#define SYS_futex 202
#endif
#ifdef unix
#include <sys/mman.h>
#include <errno.h>
#include <pthread.h>
+#include <limits.h>
#else
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
2. (set 1) NodeDelete: Exclusive. About to release the node. Incompatible with AccessIntent.
3. (set 2) ReadLock: Sharable. Read the node. Incompatible with WriteLock.
4. (set 2) WriteLock: Exclusive. Modify the node. Incompatible with ReadLock and other WriteLocks.
-5. (set 3) ParentLock: Exclusive. Have parent adopt/delete maximum foster child from the node.
+5. (set 3) ParentModification: Exclusive. Change the node's parent keys. Incompatible with another ParentModification.
*/
typedef enum{
BtLockRead,
BtLockWrite,
BtLockParent
-}BtLock;
+} BtLock;
+
+// mode & definition for latch implementation
+
+enum {
+ Mutex = 1 << 0, // the mutex bit
+ Write = 1 << 1, // the writers bit
+ Share = 1 << 2, // reader count
+ PendRd = 1 << 12, // reader contended count
+ PendWr = 1 << 22 // writer contended count
+} LockMode;
+
+enum {
+ QueRd = 1, // reader queue
+ QueWr = 2 // writer queue
+} RWQueue;
+
+// share is count of read accessors
+// grant write lock when share == 0
+
+typedef struct {
+ volatile uint mutex:1; // 1 = busy
+ volatile uint write:1; // 1 = exclusive
+ volatile uint share:10; // count of readers holding locks
+ volatile uint readwait:10; // count of readers waiting
+ volatile uint writewait:10; // count of writers waiting
+} BtLatch;
// Define the length of the page and key pointers
// by the BtSlot array of keys.
typedef struct Page {
- volatile uint cnt; // count of keys in page
- volatile uint act; // count of active keys
- volatile uint min; // next key offset
- volatile uint foster; // count of foster children
+ uint cnt; // count of keys in page
+ uint act; // count of active keys
+ uint min; // next key offset
unsigned char bits; // page size in bits
- unsigned char lvl:7; // level of page
- unsigned char dirty:1; // page needs to be cleaned
+ unsigned char lvl:6; // level of page
+ unsigned char kill:1; // page is being deleted
+ unsigned char dirty:1; // page has deleted keys
unsigned char right[BtId]; // page number to right
} *BtPage;
-// mode & definition for hash latch implementation
-
-enum {
- Mutex = 1,
- Write = 2,
- Pending = 4,
- Share = 8
-} LockMode;
-
-// mutex locks the other fields
-// exclusive is set for write access
-// share is count of read accessors
-
-typedef struct {
- volatile ushort mutex:1;
- volatile ushort exclusive:1;
- volatile ushort pending:1;
- volatile ushort share:13;
-} BtSpinLatch;
-
// hash table entries
typedef struct {
- BtSpinLatch latch[1];
+ BtLatch latch[1];
volatile ushort slot; // Latch table entry at head of chain
} BtHashEntry;
// latch manager table structure
typedef struct {
- BtSpinLatch readwr[1]; // read/write page lock
- BtSpinLatch access[1]; // Access Intent/Page delete
- BtSpinLatch parent[1]; // adoption of foster children
- BtSpinLatch busy[1]; // slot is being moved between chains
+ BtLatch readwr[1]; // read/write page lock
+ BtLatch access[1]; // Access Intent/Page delete
+ BtLatch parent[1]; // adoption of foster children
+ BtLatch busy[1]; // slot is being moved between chains
volatile ushort next; // next entry in hash table chain
volatile ushort prev; // prev entry in hash table chain
volatile ushort pin; // number of outstanding locks
unsigned long long int lru; // number of times accessed
uid basepage; // mapped base page number
char *map; // mapped memory pointer
- ushort pin; // mapped page pin counter
ushort slot; // slot index in this array
+ ushort pin; // mapped page pin counter
void *hashprev; // previous pool entry for the same hash idx
void *hashnext; // next pool entry for the same hash idx
#ifndef unix
typedef struct {
struct Page alloc[2]; // next & free page_nos in right ptr
- BtSpinLatch lock[1]; // allocation area lite latch
+ BtLatch lock[1]; // allocation area lite latch
ushort latchdeployed; // highest number of latch entries deployed
ushort nlatchpage; // number of latch pages at BT_latch
ushort latchtotal; // number of page latch entries
uint seg_bits; // seg size in pages in bits
uint mode; // read-write mode
#ifdef unix
- int idx;
char *pooladvise; // bit maps for pool page advisements
+ int idx;
#else
HANDLE idx;
#endif
ushort poolcnt; // highest page pool node in use
ushort poolmax; // highest page pool node allocated
ushort poolmask; // total number of pages in mmap segment - 1
- ushort hashsize; // size of Hash Table for pool entries
ushort evicted; // last evicted hash table slot
- ushort *hash; // hash table of pool entries
+ ushort hashsize; // size of Hash Table for pool entries
+ ushort *hash; // pool index for hash entries
BtPool *pool; // memory pool page segments
- BtSpinLatch *latch; // latches for pool hash slots
+ BtLatch *latch; // latches for pool hash slots
BtLatchMgr *latchmgr; // mapped latch page from allocation page
BtLatchSet *latchsets; // mapped latch set from latch pages
#ifndef unix
BtMgr *mgr; // buffer manager for thread
BtPage cursor; // cached frame for start/next (never mapped)
BtPage frame; // spare frame for the page split (never mapped)
- BtPage zero; // page frame for zeroes at end of file
- BtPage page; // current page
+ BtPage zero; // page of zeroes to extend the file (never mapped)
+ BtPage page; // current page mapped from file
uid page_no; // current page number
uid cursor_page; // current cursor page number
- BtLatchSet *set; // current page latch set
+ BtLatchSet *set; // current page latchset
BtPool *pool; // current page pool
unsigned char *mem; // frame, cursor, page memory buffer
int found; // last delete was found
// B-Tree functions
extern void bt_close (BtDb *bt);
extern BtDb *bt_open (BtMgr *mgr);
-extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod, uint lvl);
-extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len);
+extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uint lvl, uid id, uint tod);
+extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
extern uid bt_findkey (BtDb *bt, unsigned char *key, uint len);
extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
extern uint bt_nextkey (BtDb *bt, uint slot);
extern BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolsize, uint segsize, uint hashsize);
void bt_mgrclose (BtMgr *mgr);
-// Helper functions to return cursor slot values
+// Helper functions to return slot values
extern BtKey bt_key (BtDb *bt, uint slot);
extern uid bt_uid (BtDb *bt, uint slot);
// The first leaf page of level zero is always
// located on page 2.
+// The b-tree pages are linked with next
+// pointers to facilitate enumerators,
+// and provide for concurrency.
+
// When to root page fills, it is split in two and
// the tree height is raised by a new root at page
// one with two keys.
// page cleanup The fence key for a node is always
// present, even after deletion and cleanup.
-// Groups of pages called segments from the btree are
-// cached with memory mapping. A hash table is used to keep
+// Groups of pages called segments from the btree are optionally
+// cached with a memory mapped pool. A hash table is used to keep
// track of the cached segments. This behaviour is controlled
// by the cache block size parameter to bt_open.
// To achieve maximum concurrency one page is locked at a time
-// as the tree is traversed to find leaf key in question.
-
-// An adoption traversal leaves the parent node locked as the
-// tree is traversed to the level in quesiton.
+// as the tree is traversed to find leaf key in question. The right
+// page numbers are used in cases where the page is being split,
+// or consolidated.
// Page 0 is dedicated to lock for new page extensions,
// and chains empty pages together for reuse.
+// The ParentModification lock on a node is obtained to prevent resplitting
+// or deleting a node before its fence is posted into its upper level.
+
// Empty pages are chained together through the ALLOC page and reused.
// Access macros to address slot and key values from the page
return id;
}
+// Latch Manager
+
+int sys_futex(void *addr1, int op, int val1, struct timespec *timeout, void *addr2, int val3)
+{
+ return syscall(SYS_futex, addr1, op, val1, timeout, addr2, val3);
+}
+
// wait until write lock mode is clear
// and add 1 to the share count
-void bt_spinreadlock(BtSpinLatch *latch)
+void bt_spinreadlock(BtLatch *latch, int private)
{
-ushort prev;
+uint prev;
- do {
-#ifdef unix
- while( __sync_fetch_and_or((ushort *)latch, Mutex) & Mutex )
+ if( private )
+ private = FUTEX_PRIVATE_FLAG;
+
+ while( 1 ) {
+ // obtain latch mutex
+ if( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex ) {
sched_yield();
-#else
- while( _InterlockedOr16((ushort *)latch, Mutex) & Mutex )
- SwitchToThread();
-#endif
+ continue;
+ }
- // see if exclusive request is granted or pending
+ // wait for writers to clear
+ // increment read waiters and wait
- if( prev = !(latch->exclusive | latch->pending) )
-#ifdef unix
- __sync_fetch_and_add((ushort *)latch, Share);
-#else
- _InterlockedExchangeAdd16 ((ushort *)latch, Share);
-#endif
+ if( latch->write || latch->writewait ) {
+ __sync_fetch_and_add ((uint *)latch, PendRd);
+ prev = __sync_fetch_and_and ((uint *)latch, ~Mutex) & ~Mutex;
+ sys_futex( (uint *)latch, FUTEX_WAIT_BITSET | private, prev, NULL, NULL, QueRd );
+ __sync_fetch_and_sub ((uint *)latch, PendRd);
+ continue;
+ }
+
+ // increment reader lock count
+ // and release latch mutex
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
-#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
-#endif
- if( prev )
- return;
-#ifdef unix
- } while( sched_yield(), 1 );
-#else
- } while( SwitchToThread(), 1 );
-#endif
+ __sync_fetch_and_add ((uint *)latch, Share);
+ __sync_fetch_and_and ((uint *)latch, ~Mutex);
+ return;
+ }
}
// wait for other read and write latches to relinquish
-void bt_spinwritelock(BtSpinLatch *latch)
+void bt_spinwritelock(BtLatch *latch, int private)
{
- do {
-#ifdef unix
- while( __sync_fetch_and_or((ushort *)latch, Mutex | Pending) & Mutex )
+uint prev;
+
+ if( private )
+ private = FUTEX_PRIVATE_FLAG;
+
+ while( 1 ) {
+ // obtain latch mutex
+ if( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex ) {
sched_yield();
-#else
- while( _InterlockedOr16((ushort *)latch, Mutex | Pending) & Mutex )
- SwitchToThread();
-#endif
- if( !(latch->share | latch->exclusive) ) {
-#ifdef unix
- __sync_fetch_and_or((ushort *)latch, Write);
- __sync_fetch_and_and ((ushort *)latch, ~(Mutex | Pending));
-#else
- _InterlockedOr16((ushort *)latch, Write);
- _InterlockedAnd16((ushort *)latch, ~(Mutex | Pending));
-#endif
- return;
+ continue;
}
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
- sched_yield();
-#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
- SwitchToThread();
-#endif
- } while( 1 );
+ // wait for write and reader count to clear
+
+ if( latch->write || latch->share ) {
+ __sync_fetch_and_add ((uint *)latch, PendWr);
+ prev = __sync_fetch_and_and ((uint *)latch, ~Mutex) & ~Mutex;
+ sys_futex( (uint *)latch, FUTEX_WAIT_BITSET | private, prev, NULL, NULL, QueWr );
+ __sync_fetch_and_sub ((uint *)latch, PendWr);
+ continue;
+ }
+
+ // take write mutex
+ // release latch mutex
+
+ __sync_fetch_and_or ((uint *)latch, Write);
+ __sync_fetch_and_and ((uint *)latch, ~Mutex);
+ return;
+ }
}
// try to obtain write lock
// return 1 if obtained,
// 0 otherwise
-int bt_spinwritetry(BtSpinLatch *latch)
+int bt_spinwritetry(BtLatch *latch)
{
-ushort prev;
+int ans;
-#ifdef unix
- if( prev = __sync_fetch_and_or((ushort *)latch, Mutex), prev & Mutex )
- return 0;
-#else
- if( prev = _InterlockedOr16((ushort *)latch, Mutex), prev & Mutex )
+ // try for mutex,
+ // abandon request if not taken
+
+ if( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex )
return 0;
-#endif
- // take write access if all bits are clear
- if( !prev )
-#ifdef unix
- __sync_fetch_and_or ((ushort *)latch, Write);
-#else
- _InterlockedOr16((ushort *)latch, Write);
-#endif
+ // see if write mode is available
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
-#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
-#endif
- return !prev;
+ if( !latch->write && !latch->share ) {
+ __sync_fetch_and_or ((uint *)latch, Write);
+ ans = 1;
+ } else
+ ans = 0;
+
+ // release latch mutex
+
+ __sync_fetch_and_and ((uint *)latch, ~Mutex);
+ return ans;
}
-// clear write mode
+// clear write lock
-void bt_spinreleasewrite(BtSpinLatch *latch)
+void bt_spinreleasewrite(BtLatch *latch, int private)
{
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Write);
-#else
- _InterlockedAnd16((ushort *)latch, ~Write);
-#endif
+ if( private )
+ private = FUTEX_PRIVATE_FLAG;
+
+ // obtain latch mutex
+
+ while( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex )
+ sched_yield();
+
+ __sync_fetch_and_and ((uint *)latch, ~Write);
+
+ // favor writers
+
+ if( latch->writewait )
+ if( sys_futex( (uint *)latch, FUTEX_WAKE_BITSET | private, 1, NULL, NULL, QueWr ) )
+ goto wakexit;
+
+ if( latch->readwait )
+ sys_futex( (uint *)latch, FUTEX_WAKE_BITSET | private, INT_MAX, NULL, NULL, QueRd );
+
+ // release latch mutex
+
+wakexit:
+ __sync_fetch_and_and ((uint *)latch, ~Mutex);
}
// decrement reader count
-void bt_spinreleaseread(BtSpinLatch *latch)
+void bt_spinreleaseread(BtLatch *latch, int private)
{
-#ifdef unix
- __sync_fetch_and_add((ushort *)latch, -Share);
-#else
- _InterlockedExchangeAdd16 ((ushort *)latch, -Share);
-#endif
+ if( private )
+ private = FUTEX_PRIVATE_FLAG;
+
+ // obtain latch mutex
+
+ while( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex )
+ sched_yield();
+
+ __sync_fetch_and_sub ((uint *)latch, Share);
+
+ // wake waiting writers
+
+ if( !latch->share && latch->writewait )
+ sys_futex( (uint *)latch, FUTEX_WAKE_BITSET | private, 1, NULL, NULL, QueWr );
+
+ // release latch mutex
+
+ __sync_fetch_and_and ((uint *)latch, ~Mutex);
}
// link latch table entry into latch hash table
// obtain read lock on hash table entry
- bt_spinreadlock(bt->mgr->latchmgr->table[hashidx].latch);
+ bt_spinreadlock(bt->mgr->latchmgr->table[hashidx].latch, 0);
if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
{
#endif
}
- bt_spinreleaseread (bt->mgr->latchmgr->table[hashidx].latch);
+ bt_spinreleaseread (bt->mgr->latchmgr->table[hashidx].latch, 0);
if( slot )
return set;
// try again, this time with write lock
- bt_spinwritelock(bt->mgr->latchmgr->table[hashidx].latch);
+ bt_spinwritelock(bt->mgr->latchmgr->table[hashidx].latch, 0);
if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
{
_InterlockedIncrement16 (&set->pin);
#endif
set->page_no = page_no;
- bt_spinreleasewrite(bt->mgr->latchmgr->table[hashidx].latch);
+ bt_spinreleasewrite(bt->mgr->latchmgr->table[hashidx].latch, 0);
return set;
}
_InterlockedIncrement16 (&set->pin);
#endif
bt_latchlink (bt, hashidx, victim, page_no);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch);
+ bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch, 0);
return set;
}
// or has outstanding locks
if( !bt_spinwritetry (bt->mgr->latchmgr->table[idx].latch) ) {
- bt_spinreleasewrite (set->busy);
+ bt_spinreleasewrite (set->busy, 0);
continue;
}
if( set->pin ) {
- bt_spinreleasewrite (set->busy);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch);
+ bt_spinreleasewrite (set->busy, 0);
+ bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch, 0);
continue;
}
if( set->next )
bt->mgr->latchsets[set->next].prev = set->prev;
- bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch);
+ bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch, 0);
#ifdef unix
__sync_fetch_and_add(&set->pin, 1);
#else
_InterlockedIncrement16 (&set->pin);
#endif
bt_latchlink (bt, hashidx, victim, page_no);
- bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch);
- bt_spinreleasewrite (set->busy);
+ bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch, 0);
+ bt_spinreleasewrite (set->busy, 0);
return set;
}
}
#ifdef unix
munmap (mgr->latchsets, mgr->latchmgr->nlatchpage * mgr->page_size);
- munmap (mgr->latchmgr, mgr->page_size);
+ munmap (mgr->latchmgr, mgr->page_size);
#else
FlushViewOfFile(mgr->latchmgr, 0);
UnmapViewOfFile(mgr->latchmgr);
BtMgr* mgr;
BtKey key;
int flag;
-
#ifndef unix
SYSTEM_INFO sysinfo[1];
#endif
#ifdef unix
mgr = calloc (1, sizeof(BtMgr));
-
mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
if( mgr->idx == -1 )
else
return free(mgr), free(latchmgr), NULL;
} else if( mode == BT_ro )
- return free(latchmgr), bt_mgrclose (mgr), NULL;
+ return free(latchmgr), free (mgr), NULL;
#else
latchmgr = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
size = GetFileSize(mgr->idx, amt);
#ifdef unix
mgr->pool = calloc (poolmax, sizeof(BtPool));
mgr->hash = calloc (hashsize, sizeof(ushort));
- mgr->latch = calloc (hashsize, sizeof(BtSpinLatch));
+ mgr->latch = calloc (hashsize, sizeof(BtLatch));
mgr->pooladvise = calloc (poolmax, (mgr->poolmask + 8) / 8);
#else
mgr->pool = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, poolmax * sizeof(BtPool));
mgr->hash = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(ushort));
- mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtSpinLatch));
+ mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtLatch));
#endif
if( size || *amt )
last++;
}
+ // create empty page area by writing last page of first
+ // segment area (other pages are zeroed by O/S)
+
+ if( mgr->poolmask ) {
+ memset(latchmgr, 0, mgr->page_size);
+ last = mgr->poolmask;
+
+ while( last < MIN_lvl + 1 )
+ last += mgr->poolmask + 1;
+
+#ifdef unix
+ pwrite(mgr->idx, latchmgr, mgr->page_size, last << mgr->page_bits);
+#else
+ SetFilePointer (mgr->idx, last << mgr->page_bits, NULL, FILE_BEGIN);
+ if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
+ return bt_mgrclose (mgr), NULL;
+ if( *amt < mgr->page_size )
+ return bt_mgrclose (mgr), NULL;
+#endif
+ }
+
mgrlatch:
#ifdef unix
flag = PROT_READ | PROT_WRITE;
bt->zero = (BtPage)(bt->mem + 1 * mgr->page_size);
bt->cursor = (BtPage)(bt->mem + 2 * mgr->page_size);
- memset(bt->zero, 0, mgr->page_size);
+ memset (bt->zero, 0, mgr->page_size);
return bt;
}
node = bt->mgr->pool + hashslot;
- // scan pool entries under hash table slot
+ // scan pool entries under hash table slot
do {
if( node->pin )
pool->map = mmap (0, (bt->mgr->poolmask+1) << bt->mgr->page_bits, flag, MAP_SHARED, bt->mgr->idx, off);
if( pool->map == MAP_FAILED )
return bt->err = BTERR_map;
+
// clear out madvise issued bits
memset (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8) / 8), 0, (bt->mgr->poolmask + 8)/8);
#else
{
BtPool *pool, *node, *next;
uint slot, idx, victim;
-BtLatchSet *set;
// lock hash table chain
idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_spinreadlock (&bt->mgr->latch[idx]);
+ bt_spinreadlock (&bt->mgr->latch[idx], 1);
// look up in hash table
#else
_InterlockedIncrement16 (&pool->pin);
#endif
- bt_spinreleaseread (&bt->mgr->latch[idx]);
+ bt_spinreleaseread (&bt->mgr->latch[idx], 1);
pool->lru++;
return pool;
}
// upgrade to write lock
- bt_spinreleaseread (&bt->mgr->latch[idx]);
- bt_spinwritelock (&bt->mgr->latch[idx]);
+ bt_spinreleaseread (&bt->mgr->latch[idx], 1);
+ bt_spinwritelock (&bt->mgr->latch[idx], 1);
// try to find page in pool with write lock
#else
_InterlockedIncrement16 (&pool->pin);
#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
+ bt_spinreleasewrite (&bt->mgr->latch[idx], 1);
pool->lru++;
return pool;
}
#else
_InterlockedIncrement16 (&pool->pin);
#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
+ bt_spinreleasewrite (&bt->mgr->latch[idx], 1);
return pool;
}
if( !bt_spinwritetry (&bt->mgr->latch[victim]) )
continue;
- // if cache entry is empty
- // or no slots are unpinned
+ // if pool entry is empty
+ // or any pages are pinned
// skip this entry
if( !(pool = bt_findlru(bt, bt->mgr->hash[victim])) ) {
- bt_spinreleasewrite (&bt->mgr->latch[victim]);
+ bt_spinreleasewrite (&bt->mgr->latch[victim], 1);
continue;
}
if( node = pool->hashnext )
node->hashprev = pool->hashprev;
- bt_spinreleasewrite (&bt->mgr->latch[victim]);
+ bt_spinreleasewrite (&bt->mgr->latch[victim], 1);
// remove old file mapping
#ifdef unix
#else
_InterlockedIncrement16 (&pool->pin);
#endif
- bt_spinreleasewrite (&bt->mgr->latch[idx]);
+ bt_spinreleasewrite (&bt->mgr->latch[idx], 1);
return pool;
}
}
// place write, read, or parent lock on requested page_no.
-// pin to buffer pool and return latchset pointer
+// pin to buffer pool and return page pointer
void bt_lockpage(BtLock mode, BtLatchSet *set)
{
switch( mode ) {
case BtLockRead:
- bt_spinreadlock (set->readwr);
+ bt_spinreadlock (set->readwr, 0);
break;
case BtLockWrite:
- bt_spinwritelock (set->readwr);
+ bt_spinwritelock (set->readwr, 0);
break;
case BtLockAccess:
- bt_spinreadlock (set->access);
+ bt_spinreadlock (set->access, 0);
break;
case BtLockDelete:
- bt_spinwritelock (set->access);
+ bt_spinwritelock (set->access, 0);
break;
case BtLockParent:
- bt_spinwritelock (set->parent);
+ bt_spinwritelock (set->parent, 0);
break;
}
}
-// remove write, read, or parent lock on requested page_no.
+// remove write, read, or parent lock on requested page
void bt_unlockpage(BtLock mode, BtLatchSet *set)
{
switch( mode ) {
case BtLockRead:
- bt_spinreleaseread (set->readwr);
+ bt_spinreleaseread (set->readwr, 0);
break;
case BtLockWrite:
- bt_spinreleasewrite (set->readwr);
+ bt_spinreleasewrite (set->readwr, 0);
break;
case BtLockAccess:
- bt_spinreleaseread (set->access);
+ bt_spinreleaseread (set->access, 0);
break;
case BtLockDelete:
- bt_spinreleasewrite (set->access);
+ bt_spinreleasewrite (set->access, 0);
break;
case BtLockParent:
- bt_spinreleasewrite (set->parent);
+ bt_spinreleasewrite (set->parent, 0);
break;
}
}
// lock allocation page
- bt_spinwritelock(bt->mgr->latchmgr->lock);
+ bt_spinwritelock(bt->mgr->latchmgr->lock, 0);
// use empty chain first
// else allocate empty page
reuse = 0;
}
#ifdef unix
+ if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
+ return bt->err = BTERR_wrt, 0;
+
// if writing first page of pool block, zero last page in the block
if ( !reuse && bt->mgr->poolmask > 0 && (new_page & bt->mgr->poolmask) == 0 )
{
// use zero buffer to write zeros
+ memset(bt->zero, 0, bt->mgr->page_size);
if ( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->poolmask) << bt->mgr->page_bits) < bt->mgr->page_size )
return bt->err = BTERR_wrt, 0;
}
-
- // unlock allocation latch
-
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
-
- if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
-
#else
- // unlock allocation latch
-
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
-
// bring new page into pool and copy page.
// this will extend the file into the new pages.
- // NB -- no latch required
if( pool = bt_pinpool (bt, new_page) )
pmap = bt_page (bt, pool, new_page);
memcpy(pmap, page, bt->mgr->page_size);
bt_unpinpool (pool);
#endif
+ // unlock allocation latch and return new page no
+
+ bt_spinreleasewrite(bt->mgr->latchmgr->lock, 0);
return new_page;
}
int bt_findslot (BtDb *bt, unsigned char *key, uint len)
{
uint diff, higher = bt->page->cnt, low = 1, slot;
+uint good = 0;
+
+ // make stopper key an infinite fence value
- // low is the lowest candidate, higher is already
+ if( bt_getid (bt->page->right) )
+ higher++;
+ else
+ good++;
+
+ // low is the next candidate, higher is already
// tested as .ge. the given key, loop ends when they meet
while( diff = higher - low ) {
if( keycmp (keyptr(bt->page, slot), key, len) < 0 )
low = slot + 1;
else
- higher = slot;
+ higher = slot, good++;
}
- return higher;
+ // return zero if key is on right link page
+
+ return good ? higher : 0;
}
// find and load page at given level for given key
// leave page rd or wr locked as requested
-int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, BtLock lock)
+int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, uint lock)
{
uid page_no = ROOT_page, prevpage = 0;
BtLatchSet *set, *prevset;
// start at root of btree and drill down
+ bt->set = NULL;
+
do {
// determine lock mode of drill level
mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead;
- // obtain latch set for this page
-
bt->set = bt_pinlatch (bt, page_no);
bt->page_no = page_no;
if( page_no > ROOT_page )
bt_lockpage(BtLockAccess, bt->set);
- // now unlock and unpin our (possibly foster) parent
+ // release & unpin parent page
if( prevpage ) {
bt_unlockpage(prevmode, prevset);
// re-read and re-lock root after determining actual level of root
- if( page_no == ROOT_page )
- if( bt->page->lvl != drill) {
+ if( bt->page->lvl != drill) {
+ if ( bt->page_no != ROOT_page )
+ return bt->err = BTERR_struct, 0;
+
drill = bt->page->lvl;
- if( lock == BtLockWrite && drill == lvl ) {
+ if( lock == BtLockWrite && drill == lvl ) {
bt_unlockpage(mode, bt->set);
bt_unpinlatch (bt->set);
bt_unpinpool (bt->pool);
continue;
}
- }
-
- prevpage = bt->page_no;
- prevpool = bt->pool;
- prevset = bt->set;
- prevmode = mode;
+ }
// find key on page at this level
- // and either descend to requested level
- // or return key slot
-
- slot = bt_findslot (bt, key, len);
+ // and descend to requested level
- // is this slot < foster child area
- // on the requested level?
-
- // if so, return actual slot even if dead
-
- if( slot <= bt->page->cnt - bt->page->foster )
+ if( !bt->page->kill && (slot = bt_findslot (bt, key, len)) ) {
if( drill == lvl )
return slot;
- // find next active slot
-
- // note: foster children are never dead
- // nor fence keys for interiour nodes
-
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
- continue;
- else
- return bt->err = BTERR_struct, 0; // last key shouldn't be deleted
+ while( slotptr(bt->page, slot)->dead )
+ if( slot++ < bt->page->cnt )
+ continue;
+ else {
+ page_no = bt_getid(bt->page->right);
+ goto slideright;
+ }
- // is this slot < foster child area
- // if so, drill to next level
+ page_no = bt_getid(slotptr(bt->page, slot)->id);
+ drill--;
+ }
- if( slot <= bt->page->cnt - bt->page->foster )
- drill--;
+ // or slide right into next page
+ // (slide left from deleted page)
- // continue right onto foster child
- // or down to next level.
+ else
+ page_no = bt_getid(bt->page->right);
- page_no = bt_getid(slotptr(bt->page, slot)->id);
+ // continue down / right using overlapping locks
+ // to protect pages being killed or split.
+slideright:
+ prevpage = bt->page_no;
+ prevpool = bt->pool;
+ prevset = bt->set;
+ prevmode = mode;
} while( page_no );
- // return error on end of chain
+ // return error on end of right chain
bt->err = BTERR_struct;
return 0; // return error
}
// find and delete key on page by marking delete flag bit
-// when leaf page becomes empty, delete it from the btree
+// when page becomes empty, delete it
-BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len)
+BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl)
{
-unsigned char leftkey[256];
+unsigned char lowerkey[256], higherkey[256];
BtLatchSet *rset, *set;
BtPool *pool, *rpool;
-BtPage rpage, page;
uid page_no, right;
uint slot, tod;
+BtPage rpage;
BtKey ptr;
- if( slot = bt_loadpage (bt, key, len, 0, BtLockWrite) )
+ if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
ptr = keyptr(bt->page, slot);
else
return bt->err;
// if key is found delete it, otherwise ignore request
- // note that fence keys of interiour nodes are not deleted.
if( bt->found = !keycmp (ptr, key, len) )
if( bt->found = slotptr(bt->page, slot)->dead == 0 ) {
- slotptr(bt->page,slot)->dead = 1;
+ slotptr(bt->page,slot)->dead = 1;
if( slot < bt->page->cnt )
- bt->page->dirty = 1;
- bt->page->act--;
+ bt->page->dirty = 1;
+ bt->page->act--;
}
+ // return if page is not empty, or it has no right sibling
+
+ right = bt_getid(bt->page->right);
page_no = bt->page_no;
pool = bt->pool;
- page = bt->page;
set = bt->set;
- // return if page is not empty or not found
-
- if( page->act || !bt->found ) {
+ if( !right || bt->page->act ) {
bt_unlockpage(BtLockWrite, set);
bt_unpinlatch (set);
bt_unpinpool (pool);
return bt->err;
}
- // cache copy of fence key of empty node
-
- ptr = keyptr(page, page->cnt);
- memcpy(leftkey, ptr, ptr->len + 1);
+ // obtain Parent lock over write lock
- // release write lock on empty node
- // obtain Parent lock
-
- bt_unlockpage(BtLockWrite, set);
bt_lockpage(BtLockParent, set);
- // load and lock parent to see
- // if delete of empty node is OK
- // ie, not a fence key of parent
-
- while( 1 ) {
- if( slot = bt_loadpage (bt, leftkey+1, *leftkey, 1, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- return bt->err;
-
- // does parent level contain our fence key yet?
- // and is it free of foster children?
-
- if( !bt->page->foster )
- if( !keycmp (ptr, leftkey+1, *leftkey) )
- break;
-
- bt_unlockpage(BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- }
-
- // find our left fence key
-
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
- continue;
- else
- return bt->err = BTERR_struct; // last key shouldn't be deleted
-
- // now we have both parent and child
-
- bt_lockpage(BtLockDelete, set);
- bt_lockpage(BtLockWrite, set);
+ // keep copy of key to delete
- // return if page has no right sibling within parent
- // or if empty node is no longer empty
-
- if( page->act || slot == bt->page->cnt ) {
- // unpin parent
- bt_unlockpage(BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
- // unpin empty node
- bt_unlockpage(BtLockParent, set);
- bt_unlockpage(BtLockDelete, set);
- bt_unlockpage(BtLockWrite, set);
- bt_unpinlatch (set);
- bt_unpinpool (pool);
- return bt->err;
- }
+ ptr = keyptr(bt->page, bt->page->cnt);
+ memcpy(lowerkey, ptr, ptr->len + 1);
- // lock and map our right page
- // note that it cannot be our foster child
- // since the our node is empty
-
- right = bt_getid(page->right);
+ // lock and map right page
if( rpool = bt_pinpool (bt, right) )
rpage = bt_page (bt, rpool, right);
rset = bt_pinlatch (bt, right);
bt_lockpage(BtLockWrite, rset);
- bt_lockpage(BtLockDelete, rset);
-
- // pull contents of right page into empty page
- memcpy (page, rpage, bt->mgr->page_size);
+ // pull contents of next page into current empty page
- // delete left parent slot for old empty page
- // and redirect right parent slot to it
+ memcpy (bt->page, rpage, bt->mgr->page_size);
- bt->page->act--;
- bt->page->dirty = 1;
- slotptr(bt->page, slot)->dead = 1;
+ // keep copy of key to update
- while( slot++ < bt->page->cnt )
- if( !slotptr(bt->page, slot)->dead )
- break;
+ ptr = keyptr(rpage, rpage->cnt);
+ memcpy(higherkey, ptr, ptr->len + 1);
- bt_putid(slotptr(bt->page,slot)->id, page_no);
+ // Mark right page as deleted and point it to left page
+ // until we can post updates at higher level.
- // release parent level lock
- // and our empty node lock
+ bt_putid(rpage->right, page_no);
+ rpage->kill = 1;
+ rpage->cnt = 0;
+ bt_unlockpage(BtLockWrite, rset);
bt_unlockpage(BtLockWrite, set);
- bt_unlockpage(BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
+
+ // delete old lower key to consolidated node
+
+ if( bt_deletekey (bt, lowerkey + 1, *lowerkey, lvl + 1) )
+ return bt->err;
+
+ // redirect higher key directly to consolidated node
+
+ tod = (uint)time(NULL);
+
+ if( bt_insertkey (bt, higherkey+1, *higherkey, lvl + 1, page_no, tod) )
+ return bt->err;
// add killed right block to free chain
// lock latch mgr
- bt_spinwritelock(bt->mgr->latchmgr->lock);
+ bt_spinwritelock(bt->mgr->latchmgr->lock, 0);
// store free chain in allocation page second right
bt_putid(rpage->right, bt_getid(bt->mgr->latchmgr->alloc[1].right));
// unlock latch mgr and right page
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
+ bt_spinreleasewrite(bt->mgr->latchmgr->lock, 0);
bt_unlockpage(BtLockWrite, rset);
bt_unlockpage(BtLockDelete, rset);
// remove ParentModify lock
bt_unlockpage(BtLockParent, set);
- bt_unlockpage(BtLockDelete, set);
bt_unpinlatch (set);
bt_unpinpool (pool);
return 0;
-}
+}
// find key in leaf level and return row-id
// if key exists, return row-id
// otherwise return 0
- if( slot <= bt->page->cnt && !keycmp (ptr, key, len) )
+ if( ptr->len == len && !memcmp (ptr->key, key, len) )
id = bt_getid(slotptr(bt->page,slot)->id);
else
id = 0;
// check page for space available,
// clean if necessary and return
-// 0 - page needs splitting
-// >0 new slot value
+// =0 - page needs splitting
+// >0 - go ahead at returned slot
uint bt_cleanpage(BtDb *bt, uint amt, uint slot)
{
page->dirty = 0;
page->act = 0;
- // try cleaning up page first
-
- // always leave fence key in the array
- // otherwise, remove deleted key
-
- // note: foster children are never dead
- // nor are fence keys for interiour nodes
+ // always leave fence key in list
while( cnt++ < max ) {
if( cnt == slot )
continue;
// copy key
-
key = keyptr(bt->frame, cnt);
nxt -= key->len + 1;
memcpy ((unsigned char *)page + nxt, key, key->len + 1);
slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
slotptr(page, idx)->off = nxt;
}
-
page->min = nxt;
page->cnt = idx;
- // see if page has enough space now, or does it need splitting?
-
if( page->min >= (idx+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
return newslot;
return 0;
}
-// add key to current page
-// page must already be writelocked
-
-void bt_addkeytopage (BtDb *bt, uint slot, unsigned char *key, uint len, uid id, uint tod)
-{
-BtPage page = bt->page;
-uint idx;
-
- // find next available dead slot and copy key onto page
- // note that foster children on the page are never dead
-
- // look for next hole, but stay back from the fence key
-
- for( idx = slot; idx < page->cnt; idx++ )
- if( slotptr(page, idx)->dead )
- break;
-
- if( idx == page->cnt )
- idx++, page->cnt++;
-
- page->act++;
-
- // now insert key into array before slot
-
- while( idx > slot )
- *slotptr(page, idx) = *slotptr(page, idx -1), idx--;
-
- page->min -= len + 1;
- ((unsigned char *)page)[page->min] = len;
- memcpy ((unsigned char *)page + page->min +1, key, len );
-
- bt_putid(slotptr(page,slot)->id, id);
- slotptr(page, slot)->off = page->min;
- slotptr(page, slot)->tod = tod;
- slotptr(page, slot)->dead = 0;
-}
-
// split the root and raise the height of the btree
-// call with current page locked and page no of foster child
-// return with current page (root) unlocked
-BTERR bt_splitroot(BtDb *bt, uid right)
+BTERR bt_splitroot(BtDb *bt, unsigned char *newkey, unsigned char *oldkey, uid page_no2)
{
uint nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
BtPage root = bt->page;
uid new_page;
-BtKey key;
- // Obtain an empty page to use, and copy the left page
- // contents into it from the root. Strip foster child key.
- // (it's the stopper key)
-
- memset (slotptr(root, root->cnt), 0, sizeof(BtSlot));
- root->dirty = 1;
- root->foster--;
- root->act--;
- root->cnt--;
-
- // Save left fence key.
-
- key = keyptr(root, root->cnt);
- memcpy (fencekey, key, key->len + 1);
-
- // copy the lower keys into a new left page
+ // Obtain an empty page to use, and copy the current
+ // root contents into it which is the lower half of
+ // the old root.
if( !(new_page = bt_newpage(bt, root)) )
return bt->err;
// preserve the page info at the bottom
- // and set rest of the root to zero
+ // and set rest to zero
- memset (root+1, 0, bt->mgr->page_size - sizeof(*root));
+ memset(root+1, 0, bt->mgr->page_size - sizeof(*root));
- // insert left fence key on empty newroot page
+ // insert first key on newroot page
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
+ nxt -= *newkey + 1;
+ memcpy ((unsigned char *)root + nxt, newkey, *newkey + 1);
bt_putid(slotptr(root, 1)->id, new_page);
slotptr(root, 1)->off = nxt;
- // insert stopper key on newroot page
+ // insert second key on newroot page
// and increase the root height
- nxt -= 3;
- fencekey[0] = 2;
- fencekey[1] = 0xff;
- fencekey[2] = 0xff;
- memcpy ((unsigned char *)root + nxt, fencekey, *fencekey + 1);
- bt_putid(slotptr(root, 2)->id, right);
+ nxt -= *oldkey + 1;
+ memcpy ((unsigned char *)root + nxt, oldkey, *oldkey + 1);
+ bt_putid(slotptr(root, 2)->id, page_no2);
slotptr(root, 2)->off = nxt;
bt_putid(root->right, 0);
}
// split already locked full node
-// in current page variables
-// return unlocked and unpinned.
+// return unlocked.
BTERR bt_splitpage (BtDb *bt)
{
-uint slot, cnt, idx, max, nxt = bt->mgr->page_size;
-unsigned char fencekey[256];
-uid page_no = bt->page_no;
-BtLatchSet *set = bt->set;
+uint cnt = 0, idx = 0, max, nxt = bt->mgr->page_size;
+unsigned char oldkey[256], lowerkey[256];
+uid page_no = bt->page_no, right;
+BtLatchSet *nset, *set = bt->set;
BtPool *pool = bt->pool;
BtPage page = bt->page;
-uint tod = time(NULL);
uint lvl = page->lvl;
-uid new_page, right;
+uid new_page;
BtKey key;
+uint tod;
- // initialize frame buffer for right node
+ // split higher half of keys to bt->frame
+ // the last key (fence key) might be dead
- memset (bt->frame, 0, bt->mgr->page_size);
- max = page->cnt - page->foster;
tod = (uint)time(NULL);
+
+ memset (bt->frame, 0, bt->mgr->page_size);
+ max = (int)page->cnt;
cnt = max / 2;
idx = 0;
- // split higher half of keys to bt->frame
- // leaving old foster children in the left node,
- // and adding a new foster child there.
-
while( cnt++ < max ) {
key = keyptr(page, cnt);
nxt -= key->len + 1;
slotptr(bt->frame, idx)->off = nxt;
}
- // transfer right link node to new right node
+ // remember existing fence key for new page to the right
- if( page_no > ROOT_page ) {
- right = bt_getid (page->right);
- bt_putid(bt->frame->right, right);
- }
+ memcpy (oldkey, key, key->len + 1);
bt->frame->bits = bt->mgr->page_bits;
bt->frame->min = nxt;
bt->frame->cnt = idx;
bt->frame->lvl = lvl;
- // get new free page and write right frame to it.
+ // link right node
- if( !(new_page = bt_newpage(bt, bt->frame)) )
- return bt->err;
+ if( page_no > ROOT_page ) {
+ right = bt_getid (page->right);
+ bt_putid(bt->frame->right, right);
+ }
- // remember fence key for new right page to add
- // as foster child to the left node
+ // get new free page and write frame to it.
- key = keyptr(bt->frame, idx);
- memcpy (fencekey, key, key->len + 1);
+ if( !(new_page = bt_newpage(bt, bt->frame)) )
+ return bt->err;
- // update lower keys and foster children to continue in old page
+ // update lower keys to continue in old page
memcpy (bt->frame, page, bt->mgr->page_size);
memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
nxt = bt->mgr->page_size;
- page->dirty = 0;
page->act = 0;
cnt = 0;
idx = 0;
// assemble page of smaller keys
- // to remain in the old page
+ // (they're all active keys)
while( cnt++ < max / 2 ) {
key = keyptr(bt->frame, cnt);
nxt -= key->len + 1;
memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- if( !(slotptr(page, idx)->dead = slotptr(bt->frame, cnt)->dead) )
- page->act++;
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- }
-
- // insert new foster child for right page in queue
- // before any of the current foster children
-
- nxt -= *fencekey + 1;
- memcpy ((unsigned char *)page + nxt, fencekey, *fencekey + 1);
-
- bt_putid (slotptr(page,++idx)->id, new_page);
- slotptr(page, idx)->tod = tod;
- slotptr(page, idx)->off = nxt;
- page->foster++;
- page->act++;
-
- // continue with old foster child keys
- // note that none will be dead
-
- cnt = bt->frame->cnt - bt->frame->foster;
-
- while( cnt++ < bt->frame->cnt ) {
- key = keyptr(bt->frame, cnt);
- nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy (slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
+ memcpy(slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
slotptr(page, idx)->off = nxt;
page->act++;
}
+ // remember fence key for old page
+
+ memcpy(lowerkey, key, key->len + 1);
+ bt_putid(page->right, new_page);
page->min = nxt;
page->cnt = idx;
- // link new right page
-
- bt_putid (page->right, new_page);
-
// if current page is the root page, split it
if( page_no == ROOT_page )
- return bt_splitroot (bt, new_page);
+ return bt_splitroot (bt, lowerkey, oldkey, new_page);
- // release wr lock on our page
+ // release wr lock on left page
bt_unlockpage (BtLockWrite, set);
- // obtain ParentModification lock for current page
- // to fix new fence key and oldest foster child on page
+ // obtain Parent/Write locks
+ // for left and right node pages
- bt_lockpage (BtLockParent, set);
+ nset = bt_pinlatch (bt, new_page);
- // get our new fence key to insert in parent node
-
- bt_lockpage (BtLockRead, set);
-
- key = keyptr(page, page->cnt-1);
- memcpy (fencekey, key, key->len+1);
+ bt_lockpage (BtLockParent, nset);
+ bt_lockpage (BtLockParent, set);
- bt_unlockpage (BtLockRead, set);
+ // insert new fence for reformulated left block
- if( bt_insertkey (bt, fencekey + 1, *fencekey, page_no, tod, lvl + 1) )
+ if( bt_insertkey (bt, lowerkey+1, *lowerkey, lvl + 1, page_no, tod) )
return bt->err;
- // lock our page for writing
-
- bt_lockpage (BtLockRead, set);
-
- // switch old parent key from us to our oldest foster child
+ // fix old fence for newly allocated right block page
- key = keyptr(page, page->cnt);
- memcpy (fencekey, key, key->len+1);
-
- new_page = bt_getid (slotptr(page, page->cnt)->id);
- bt_unlockpage (BtLockRead, set);
-
- if( bt_insertkey (bt, fencekey + 1, *fencekey, new_page, tod, lvl + 1) )
+ if( bt_insertkey (bt, oldkey+1, *oldkey, lvl + 1, new_page, tod) )
return bt->err;
- // now that it has its own parent pointer,
- // remove oldest foster child from our page
-
- bt_lockpage (BtLockWrite, set);
- memset (slotptr(page, page->cnt), 0, sizeof(BtSlot));
- page->dirty = 1;
- page->foster--;
- page->cnt--;
- page->act--;
+ // release Parent locks
- // unlock and unpin
-
- bt_unlockpage (BtLockWrite, set);
+ bt_unlockpage (BtLockParent, nset);
bt_unlockpage (BtLockParent, set);
+ bt_unpinlatch (nset);
bt_unpinlatch (set);
bt_unpinpool (pool);
return 0;
}
-// Insert new key into the btree at leaf level.
+// Insert new key into the btree at requested level.
+// Level zero pages are leaf pages. Page is unlocked at exit.
-BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod, uint lvl)
+BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uint lvl, uid id, uint tod)
{
uint slot, idx;
BtPage page;
BtKey ptr;
- while( 1 ) {
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- {
- if ( !bt->err )
- bt->err = BTERR_ovflw;
- return bt->err;
- }
+ while( 1 ) {
+ if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
+ ptr = keyptr(bt->page, slot);
+ else
+ {
+ if ( !bt->err )
+ bt->err = BTERR_ovflw;
+ return bt->err;
+ }
- // if key already exists, update id and return
+ // if key already exists, update id and return
- page = bt->page;
+ page = bt->page;
- if( !keycmp (ptr, key, len) ) {
- if( slotptr(page, slot)->dead )
- page->act++;
- slotptr(page, slot)->dead = 0;
- slotptr(page, slot)->tod = tod;
- bt_putid(slotptr(page,slot)->id, id);
- bt_unlockpage(BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
- return bt->err;
- }
+ if( !keycmp (ptr, key, len) ) {
+ slotptr(page, slot)->dead = 0;
+ slotptr(page, slot)->tod = tod;
+ bt_putid(slotptr(page,slot)->id, id);
+ bt_unlockpage(BtLockWrite, bt->set);
+ bt_unpinlatch(bt->set);
+ bt_unpinpool (bt->pool);
+ return bt->err;
+ }
- // check if page has enough space
+ // check if page has enough space
- if( slot = bt_cleanpage (bt, len, slot) )
- break;
+ if( slot = bt_cleanpage (bt, len, slot) )
+ break;
- if( bt_splitpage (bt) )
- return bt->err;
- }
+ if( bt_splitpage (bt) )
+ return bt->err;
+ }
- bt_addkeytopage (bt, slot, key, len, id, tod);
+ // calculate next available slot and copy key into page
- bt_unlockpage (BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
- return 0;
+ page->min -= len + 1; // reset lowest used offset
+ ((unsigned char *)page)[page->min] = len;
+ memcpy ((unsigned char *)page + page->min +1, key, len );
+
+ for( idx = slot; idx < page->cnt; idx++ )
+ if( slotptr(page, idx)->dead )
+ break;
+
+ // now insert key into array before slot
+ // preserving the fence slot
+
+ if( idx == page->cnt )
+ idx++, page->cnt++;
+
+ page->act++;
+
+ while( idx > slot )
+ *slotptr(page, idx) = *slotptr(page, idx -1), idx--;
+
+ bt_putid(slotptr(page,slot)->id, id);
+ slotptr(page, slot)->off = page->min;
+ slotptr(page, slot)->tod = tod;
+ slotptr(page, slot)->dead = 0;
+
+ bt_unlockpage (BtLockWrite, bt->set);
+ bt_unpinlatch (bt->set);
+ bt_unpinpool (bt->pool);
+ return 0;
}
// cache page of keys into cursor and return starting slot for given key
// cache page for retrieval
if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
memcpy (bt->cursor, bt->page, bt->mgr->page_size);
-
bt->cursor_page = bt->page_no;
-
bt_unlockpage(BtLockRead, bt->set);
bt_unpinlatch (bt->set);
bt_unpinpool (bt->pool);
uint bt_nextkey (BtDb *bt, uint slot)
{
-BtLatchSet *set;
BtPool *pool;
BtPage page;
uid right;
do {
right = bt_getid(bt->cursor->right);
- while( slot++ < bt->cursor->cnt - bt->cursor->foster )
+ while( slot++ < bt->cursor->cnt )
if( slotptr(bt->cursor,slot)->dead )
continue;
- else if( right || (slot < bt->cursor->cnt - bt->cursor->foster) )
+ else if( right || (slot < bt->cursor->cnt))
return slot;
else
break;
break;
bt->cursor_page = right;
+
if( pool = bt_pinpool (bt, right) )
page = bt_page (bt, pool, right);
else
return 0;
- set = bt_pinlatch (bt, right);
- bt_lockpage(BtLockRead, set);
+ bt->set = bt_pinlatch (bt, right);
+ bt_lockpage(BtLockRead, bt->set);
memcpy (bt->cursor, page, bt->mgr->page_size);
- bt_unlockpage(BtLockRead, set);
- bt_unpinlatch (set);
+ bt_unlockpage(BtLockRead, bt->set);
+ bt_unpinlatch (bt->set);
bt_unpinpool (pool);
slot = 0;
} while( 1 );
return slotptr(bt->cursor,slot)->tod;
}
-
#ifdef STANDALONE
void bt_latchaudit (BtDb *bt)
}
for( hashidx = 0; hashidx < bt->mgr->latchmgr->latchhash; hashidx++ ) {
- if( *(ushort *)bt->mgr->latchmgr->table[hashidx].latch )
+ if( *(uint *)bt->mgr->latchmgr->table[hashidx].latch )
fprintf(stderr, "latchmgr locked\n");
if( idx = bt->mgr->latchmgr->table[hashidx].slot ) do {
set = bt->mgr->latchsets + idx;
- if( *(ushort *)set->readwr || *(ushort *)set->access || *(ushort *)set->parent )
+ if( *(uint *)set->readwr || *(ushort *)set->access || *(ushort *)set->parent )
fprintf(stderr, "latchset %d locked\n", idx);
if( set->hash != hashidx )
fprintf(stderr, "latchset %d wrong hashidx\n", idx);
unsigned char key[256];
ThreadArg *args = arg;
int ch, len = 0, slot;
-BtLatchSet *set;
time_t tod[1];
BtPool *pool;
BtPage page;
bt_latchaudit (bt);
fprintf(stderr, "finished latch mgr audit\n");
break;
+
case 'w':
fprintf(stderr, "started indexing for %s\n", args->infile);
if( in = fopen (args->infile, "rb") )
else if( args->num )
sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
- if( bt_insertkey (bt, key, len, line, *tod, 0) )
+ if( bt_insertkey (bt, key, len, 0, line, *tod) )
fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
len = 0;
}
else if( args->num )
sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
- if( bt_deletekey (bt, key, len) )
+ if( bt_deletekey (bt, key, len, 0) )
fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
len = 0;
}
fprintf(stderr, "started reading\n");
do {
- if( pool = bt_pinpool (bt, page_no) )
- page = bt_page (bt, pool, page_no);
+ if( bt->pool = bt_pinpool (bt, page_no) )
+ page = bt_page (bt, bt->pool, page_no);
else
break;
- set = bt_pinlatch (bt, page_no);
- bt_lockpage (BtLockRead, set);
+ bt->set = bt_pinlatch (bt, page_no);
+ bt_lockpage (BtLockRead, bt->set);
cnt += page->act;
next = bt_getid (page->right);
- bt_unlockpage (BtLockRead, set);
- bt_unpinlatch (set);
- bt_unpinpool (pool);
+ bt_unlockpage (BtLockRead, bt->set);
+ bt_unpinlatch (bt->set);
+ bt_unpinpool (bt->pool);
} while( page_no = next );
cnt--; // remove stopper key
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