+++ /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
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