From 6b4425e582af0e64d26e45936240f78ac5936d46 Mon Sep 17 00:00:00 2001 From: unknown Date: Wed, 19 Feb 2014 11:09:21 -0800 Subject: [PATCH] Remove foster btree from project. It doesn't add anything. --- README.md | 8 - fosterbtreee.c | 2825 ------------------------------------------------ fosterbtreef.c | 2727 ---------------------------------------------- fosterbtreeg.c | 2770 ----------------------------------------------- 4 files changed, 8330 deletions(-) delete mode 100644 fosterbtreee.c delete mode 100644 fosterbtreef.c delete mode 100644 fosterbtreeg.c diff --git a/README.md b/README.md index 9210f42..468f624 100644 --- a/README.md +++ b/README.md @@ -13,14 +13,6 @@ threads2i.c Multi-Threaded/Multi-Process with latching implemented by a latc threads2j.c Multi-Threaded/Multi-Process with latching implemented by a latch manager with test & set locks in the first few btree pages with Linux futex system calls during contention. Recommended for linux. -The Foster code set includes the same three types of latching: - -Fosterbtreee.c Multi-Threaded/Single Process with latching implemented by a latch manager with pthreads/SRW latches in the first few btree pages. - -Fosterbtreef.c Multi-Threaded/Multi-Process with latching implemented by a latch manager with test & set latches in the first few btree pages with thread yield system calls during contention. - -Fosterbtreeg.c Multi-Threaded/Multi-Process with latching implemented by a latch manager with test & set locks in the first few btree pages with Linux futex system calls during contention. - Compilation is achieved on linux or Windows by: gcc -D STANDALONE threads2h.c -lpthread diff --git a/fosterbtreee.c b/fosterbtreee.c deleted file mode 100644 index 89be3c0..0000000 --- a/fosterbtreee.c +++ /dev/null @@ -1,2825 +0,0 @@ -// foster btree version e -// 29 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 -#include -#include -#include -#include -#include -#include -#include -#else -#define WIN32_LEAN_AND_MEAN -#include -#include -#include -#include -#include -#include -#include -#endif - -#include -#include - -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; -#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 foster; // last search was to foster child - 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); - -// internal functions -BTERR bt_splitpage (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no); -uint bt_cleanpage(BtDb *bt, BtPage page, uint amt, uint slot); -BTERR bt_mergeleft (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl); - -// 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); -#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)); -#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; -#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)); - 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; -uint good = 0; - - // if no right link - // make stopper key an infinite fence value - // by setting the good flag - - if( bt_getid (bt->page->right) ) - higher++; - else - good++; - - // low is the next candidate. - // loop ends when they meet - - // if good, higher is already - // tested as .ge. the given key. - - while( diff = higher - low ) { - slot = low + ( diff >> 1 ); - if( keycmp (keyptr(bt->page, slot), key, len) < 0 ) - low = slot + 1; - else - higher = slot, good++; - } - - // 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 - -uint 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; -int foster = 0; - - // 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; - } - } - - // find key on page at this level - // and either descend to requested level - // or return key slot - - if( 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 bt->foster = foster, slot; - - // find next active slot - // note: foster children are never dead - - while( slotptr(bt->page, slot)->dead ) - if( slot++ < bt->page->cnt ) - continue; - else { - // we are waiting for fence key posting - page_no = bt_getid(bt->page->right); - goto slideright; - } - - // is this slot < foster child area - // if so, drill to next level - - if( slot <= bt->page->cnt - bt->page->foster ) - foster = 0, drill--; - else - foster = 1; - - // continue right onto foster child - // or down to next level. - - page_no = bt_getid(slotptr(bt->page, slot)->id); - - // or slide right into next page - - } else { - page_no = bt_getid(bt->page->right); - foster = 1; - } - -slideright: - prevpage = bt->page_no; - prevpool = bt->pool; - prevset = bt->set; - prevmode = mode; - - } while( page_no ); - - // return error on end of chain - - bt->err = BTERR_struct; - return 0; // return error -} - -// remove empty page from the B-tree -// by pulling our right node left over ourselves - -// call with bt->page, etc, set to page's locked parent -// returns with page locked. - -BTERR bt_mergeright (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl, uint slot) -{ -BtLatchSet *rset, *pset, *rpset; -BtPool *rpool, *ppool, *rppool; -BtPage rpage, ppage, rppage; -uid right, parent, rparent; -BtKey ptr; -uint idx; - - // cache node's parent page - - parent = bt->page_no; - ppage = bt->page; - ppool = bt->pool; - pset = bt->set; - - // lock and map our right page - // note that it cannot be our foster child - // since the our node is empty - // and it cannot be NULL because of the stopper - // in the last right page - - bt_lockpage (BtLockWrite, set); - - // if we aren't dead yet - - if( page->act ) - goto rmergexit; - - if( right = bt_getid (page->right) ) - if( rpool = bt_pinpool (bt, right) ) - rpage = bt_page (bt, rpool, right); - else - return bt->err; - else - return bt->err = BTERR_struct; - - rset = bt_pinlatch (bt, right); - - // find our right neighbor - - if( ppage->act > 1 ) { - for( idx = slot; idx++ < ppage->cnt; ) - if( !slotptr(ppage, idx)->dead ) - break; - - if( idx > ppage->cnt ) - return bt->err = BTERR_struct; - - // redirect right neighbor in parent to left node - - bt_putid(slotptr(ppage,idx)->id, page_no); - } - - // if parent has only our deleted page, e.g. no right neighbor - // prepare to merge parent itself - - if( ppage->act == 1 ) { - if( rparent = bt_getid (ppage->right) ) - if( rppool = bt_pinpool (bt, rparent) ) - rppage = bt_page (bt, rppool, rparent); - else - return bt->err; - else - return bt->err = BTERR_struct; - - rpset = bt_pinlatch (bt, rparent); - bt_lockpage (BtLockWrite, rpset); - - // find our right neighbor on right parent page - - for( idx = 0; idx++ < rppage->cnt; ) - if( !slotptr(rppage, idx)->dead ) { - bt_putid (slotptr(rppage, idx)->id, page_no); - break; - } - - if( idx > rppage->cnt ) - return bt->err = BTERR_struct; - } - - // now that there are no more pointers to our right node - // we can wait for delete lock on it - - bt_lockpage(BtLockDelete, rset); - bt_lockpage(BtLockWrite, rset); - - // pull contents of right page into our empty page - - memcpy (page, rpage, bt->mgr->page_size); - - // ready to release right parent lock - // now that we have a new page in place - - if( ppage->act == 1 ) { - bt_unlockpage (BtLockWrite, rpset); - bt_unpinlatch (rpset); - bt_unpinpool (rppool); - } - - // 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_unlockpage(BtLockDelete, rset); - bt_unlockpage(BtLockWrite, rset); - bt_unpinlatch (rset); - bt_unpinpool (rpool); - - bt_spinreleasewrite(bt->mgr->latchmgr->lock); - - // delete our obsolete fence key from our parent - - slotptr(ppage, slot)->dead = 1; - ppage->dirty = 1; - - // if our parent now empty - // remove it from the tree - - if( ppage->act-- == 1 ) - if( bt_mergeleft (bt, ppage, ppool, pset, parent, lvl+1) ) - return bt->err; - -rmergexit: - bt_unlockpage (BtLockWrite, pset); - bt_unpinlatch (pset); - bt_unpinpool (ppool); - - bt->found = 1; - return bt->err = 0; -} - -// remove empty page from the B-tree -// try merging left first. If no left -// sibling, then merge right. - -// call with page loaded and locked, -// return with page locked. - -BTERR bt_mergeleft (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl) -{ -unsigned char fencekey[256], postkey[256]; -uint slot, idx, postfence = 0; -BtLatchSet *lset, *pset; -BtPool *lpool, *ppool; -BtPage lpage, ppage; -uid left, parent; -BtKey ptr; - - ptr = keyptr(page, page->cnt); - memcpy(fencekey, ptr, ptr->len + 1); - bt_unlockpage (BtLockWrite, set); - - // load and lock our parent - -retry: - if( !(slot = bt_loadpage (bt, fencekey+1, *fencekey, lvl+1, BtLockWrite)) ) - return bt->err; - - parent = bt->page_no; - ppage = bt->page; - ppool = bt->pool; - pset = bt->set; - - // wait until we are not a foster child - - if( bt->foster ) { - bt_unlockpage (BtLockWrite, pset); - bt_unpinlatch (pset); - bt_unpinpool (ppool); -#ifdef unix - sched_yield(); -#else - SwitchToThread(); -#endif - goto retry; - } - - // find our left neighbor in our parent page - - for( idx = slot; --idx; ) - if( !slotptr(ppage, idx)->dead ) - break; - - // if no left neighbor, do right merge - - if( !idx ) - return bt_mergeright (bt, page, pool, set, page_no, lvl, slot); - - // lock and map our left neighbor's page - - left = bt_getid (slotptr(ppage, idx)->id); - - if( lpool = bt_pinpool (bt, left) ) - lpage = bt_page (bt, lpool, left); - else - return bt->err; - - lset = bt_pinlatch (bt, left); - bt_lockpage(BtLockWrite, lset); - - // wait until foster sibling is in our parent - - if( bt_getid (lpage->right) != page_no ) { - bt_unlockpage (BtLockWrite, pset); - bt_unpinlatch (pset); - bt_unpinpool (ppool); - bt_unlockpage (BtLockWrite, lset); - bt_unpinlatch (lset); - bt_unpinpool (lpool); -#ifdef linux - sched_yield(); -#else - SwitchToThread(); -#endif - goto retry; - } - - // since our page will have no more pointers to it, - // obtain Delete lock and wait for write locks to clear - - bt_lockpage(BtLockDelete, set); - bt_lockpage(BtLockWrite, set); - - // if we aren't dead yet, - // get ready for exit - - if( page->act ) { - bt_unlockpage(BtLockDelete, set); - bt_unlockpage(BtLockWrite, lset); - bt_unpinlatch (lset); - bt_unpinpool (lpool); - goto lmergexit; - } - - // are we are the fence key for our parent? - // if so, grab our old fence key - - if( postfence = slot == ppage->cnt ) { - ptr = keyptr (ppage, ppage->cnt); - memcpy(fencekey, ptr, ptr->len + 1); - memset(slotptr(ppage, ppage->cnt), 0, sizeof(BtSlot)); - - // clear out other dead slots - - while( --ppage->cnt ) - if( slotptr(ppage, ppage->cnt)->dead ) - memset(slotptr(ppage, ppage->cnt), 0, sizeof(BtSlot)); - else - break; - - ptr = keyptr (ppage, ppage->cnt); - memcpy(postkey, ptr, ptr->len + 1); - } else - slotptr(ppage,slot)->dead = 1; - - ppage->dirty = 1; - ppage->act--; - - // push our right neighbor pointer to our left - - memcpy (lpage->right, page->right, BtId); - - // add ourselves to free chain - // lock latch mgr - - bt_spinwritelock(bt->mgr->latchmgr->lock); - - // store free chain in allocation page second right - bt_putid(page->right, bt_getid(bt->mgr->latchmgr->alloc[1].right)); - bt_putid(bt->mgr->latchmgr->alloc[1].right, page_no); - - // unlock latch mgr and pages - - bt_spinreleasewrite(bt->mgr->latchmgr->lock); - bt_unlockpage(BtLockWrite, lset); - bt_unpinlatch (lset); - bt_unpinpool (lpool); - - // release our node's delete lock - - bt_unlockpage(BtLockDelete, set); - -lmergexit: - bt_unlockpage (BtLockWrite, pset); - bt_unpinpool (ppool); - - // do we need to post parent's fence key in its parent? - - if( !postfence || parent == ROOT_page ) { - bt_unpinlatch (pset); - bt->found = 1; - return bt->err = 0; - } - - // interlock parent fence post - - bt_lockpage (BtLockParent, pset); - - // load parent's parent page -posttry: - if( !(slot = bt_loadpage (bt, fencekey+1, *fencekey, lvl+2, BtLockWrite)) ) - return bt->err; - - if( !(slot = bt_cleanpage (bt, bt->page, *fencekey, slot)) ) - if( bt_splitpage (bt, bt->page, bt->pool, bt->set, bt->page_no) ) - return bt->err; - else - goto posttry; - - page = bt->page; - - page->min -= *postkey + 1; - ((unsigned char *)page)[page->min] = *postkey; - memcpy ((unsigned char *)page + page->min +1, postkey + 1, *postkey ); - slotptr(page, slot)->off = page->min; - - bt_unlockpage (BtLockParent, pset); - bt_unpinlatch (pset); - - bt_unlockpage (BtLockWrite, bt->set); - bt_unpinlatch (bt->set); - bt_unpinpool (bt->pool); - - bt->found = 1; - return bt->err = 0; -} - -// find and delete key on page by marking delete flag bit -// if page becomes empty, delete it from the btree - -BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len) -{ -BtLatchSet *set; -BtPool *pool; -BtPage page; -uid page_no; -BtKey ptr; -uint slot; - - if( !(slot = bt_loadpage (bt, key, len, 0, BtLockWrite)) ) - return bt->err; - - page_no = bt->page_no; - page = bt->page; - pool = bt->pool; - set = bt->set; - - // if key is found delete it, otherwise ignore request - - ptr = keyptr(page, slot); - - if( bt->found = !keycmp (ptr, key, len) ) - if( bt->found = slotptr(page, slot)->dead == 0 ) { - slotptr(page,slot)->dead = 1; - if( slot < page->cnt ) - page->dirty = 1; - if( !--page->act ) - if( bt_mergeleft (bt, page, pool, set, page_no, 0) ) - return bt->err; - } - - bt_unlockpage(BtLockWrite, set); - bt_unpinlatch (set); - bt_unpinpool (pool); - return bt->err = 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, BtPage page, uint amt, uint slot) -{ -uint nxt = bt->mgr->page_size; -uint cnt = 0, idx = 0; -uint max = page->cnt; -uint newslot = max; -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 - - while( cnt++ < max ) { - if( cnt == slot ) - newslot = idx + 1; - 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, BtPage page, uint slot, unsigned char *key, uint len, uid id, uint tod) -{ -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 -// return unlocked and unpinned. - -BTERR bt_splitpage (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no) -{ -uint slot, cnt, idx, max, nxt = bt->mgr->page_size; -unsigned char fencekey[256]; -uint tod = time(NULL); -uint lvl = page->lvl; -uid new_page; -BtKey key; - - // initialize frame buffer for right node - - memset (bt->frame, 0, bt->mgr->page_size); - max = page->cnt - page->foster; - 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 ) - memcpy (bt->frame->right, page->right, BtId); - - 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--; - - bt_unlockpage (BtLockParent, set); - - // if this emptied page, - // undo the foster child - - if( !page->act ) - if( bt_mergeleft (bt, page, pool, set, page_no, lvl) ) - return bt->err; - - // unlock and unpin - - bt_unlockpage (BtLockWrite, 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, bt->page, len, slot) ) - break; - - if( bt_splitpage (bt, bt->page, bt->pool, bt->set, bt->page_no) ) - return bt->err; - } - - bt_addkeytopage (bt, bt->page, 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 - -void bt_latchaudit (BtDb *bt) -{ -ushort idx, hashidx; -BtLatchSet *set; -BtPool *pool; -BtPage page; -uid page_no; - -#ifdef unix - for( idx = 1; idx < bt->mgr->latchmgr->latchdeployed; idx++ ) { - set = bt->mgr->latchsets + idx; - if( set->pin ) { - fprintf(stderr, "latchset %d pinned\n", idx); - set->pin = 0; - } - } - - for( hashidx = 0; hashidx < bt->mgr->latchmgr->latchhash; hashidx++ ) { - if( idx = bt->mgr->latchmgr->table[hashidx].slot ) do { - set = bt->mgr->latchsets + idx; - if( set->hash != hashidx ) - fprintf(stderr, "latchset %d wrong hashidx\n", idx); - if( set->pin ) - fprintf(stderr, "latchset %d pinned\n", idx); - } while( idx = set->next ); - } - page_no = LEAF_page; - - while( page_no ) { - fprintf(stderr, "page: %.6x\n", (uint)page_no); - pool = bt_pinpool (bt, page_no); - page = bt_page (bt, pool, page_no); - page_no = bt_getid(page->right); - bt_unpinpool (pool); - } - - page_no = bt_getid(bt->mgr->latchmgr->alloc[1].right); - - while( page_no ) { - fprintf(stderr, "free: %.6x\n", (uint)page_no); - pool = bt_pinpool (bt, page_no); - page = bt_page (bt, pool, page_no); - page_no = bt_getid(page->right); - bt_unpinpool (pool); - } -#endif -} - -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 'a': - fprintf(stderr, "started latch mgr audit\n"); - 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") ) - 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 diff --git a/fosterbtreef.c b/fosterbtreef.c deleted file mode 100644 index c437900..0000000 --- a/fosterbtreef.c +++ /dev/null @@ -1,2727 +0,0 @@ -// foster btree version f -// 29 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 -#include -#include -#include -#include -#include -#include -#include -#else -#define WIN32_LEAN_AND_MEAN -#include -#include -#include -#include -#include -#include -#include -#endif - -#include -#include - -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 { - 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; -#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 foster; // last search was to foster child - 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); - -// internal functions -BTERR bt_splitpage (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no); -uint bt_cleanpage(BtDb *bt, BtPage page, uint amt, uint slot); -BTERR bt_mergeleft (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl); - -// 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); - sched_yield(); -#else - _InterlockedAnd16((ushort *)latch, ~Mutex); - 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; -} - -// release latch pin - -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_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_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); -#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), 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)); -#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); - - 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; -} - -// 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; -#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)); - 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_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; - } -} - -// remove write, read, or parent lock on requested page_no. - -void bt_unlockpage(BtLock mode, BtLatchSet *set) -{ - 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; - } -} - -// 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; -uint good = 0; - - // if no right link - // make stopper key an infinite fence value - // by setting the good flag - - if( bt_getid (bt->page->right) ) - higher++; - else - good++; - - // low is the next candidate. - // loop ends when they meet - - // if good, higher is already - // tested as .ge. the given key. - - while( diff = higher - low ) { - slot = low + ( diff >> 1 ); - if( keycmp (keyptr(bt->page, slot), key, len) < 0 ) - low = slot + 1; - else - higher = slot, good++; - } - - // 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 - -uint 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; -int foster = 0; - - // 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; - } - } - - // find key on page at this level - // and either descend to requested level - // or return key slot - - if( 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 bt->foster = foster, slot; - - // find next active slot - // note: foster children are never dead - - while( slotptr(bt->page, slot)->dead ) - if( slot++ < bt->page->cnt ) - continue; - else { - // we are waiting for fence key posting - page_no = bt_getid(bt->page->right); - goto slideright; - } - - // is this slot < foster child area - // if so, drill to next level - - if( slot <= bt->page->cnt - bt->page->foster ) - foster = 0, drill--; - else - foster = 1; - - // continue right onto foster child - // or down to next level. - - page_no = bt_getid(slotptr(bt->page, slot)->id); - - // or slide right into next page - - } else { - page_no = bt_getid(bt->page->right); - foster = 1; - } - -slideright: - prevpage = bt->page_no; - prevpool = bt->pool; - prevset = bt->set; - prevmode = mode; - - } while( page_no ); - - // return error on end of chain - - bt->err = BTERR_struct; - return 0; // return error -} - -// remove empty page from the B-tree -// by pulling our right node left over ourselves - -// call with bt->page, etc, set to page's locked parent -// returns with page locked. - -BTERR bt_mergeright (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl, uint slot) -{ -BtLatchSet *rset, *pset, *rpset; -BtPool *rpool, *ppool, *rppool; -BtPage rpage, ppage, rppage; -uid right, parent, rparent; -BtKey ptr; -uint idx; - - // cache node's parent page - - parent = bt->page_no; - ppage = bt->page; - ppool = bt->pool; - pset = bt->set; - - // lock and map our right page - // note that it cannot be our foster child - // since the our node is empty - // and it cannot be NULL because of the stopper - // in the last right page - - bt_lockpage (BtLockWrite, set); - - // if we aren't dead yet - - if( page->act ) - goto rmergexit; - - if( right = bt_getid (page->right) ) - if( rpool = bt_pinpool (bt, right) ) - rpage = bt_page (bt, rpool, right); - else - return bt->err; - else - return bt->err = BTERR_struct; - - rset = bt_pinlatch (bt, right); - - // find our right neighbor - - if( ppage->act > 1 ) { - for( idx = slot; idx++ < ppage->cnt; ) - if( !slotptr(ppage, idx)->dead ) - break; - - if( idx > ppage->cnt ) - return bt->err = BTERR_struct; - - // redirect right neighbor in parent to left node - - bt_putid(slotptr(ppage,idx)->id, page_no); - } - - // if parent has only our deleted page, e.g. no right neighbor - // prepare to merge parent itself - - if( ppage->act == 1 ) { - if( rparent = bt_getid (ppage->right) ) - if( rppool = bt_pinpool (bt, rparent) ) - rppage = bt_page (bt, rppool, rparent); - else - return bt->err; - else - return bt->err = BTERR_struct; - - rpset = bt_pinlatch (bt, rparent); - bt_lockpage (BtLockWrite, rpset); - - // find our right neighbor on right parent page - - for( idx = 0; idx++ < rppage->cnt; ) - if( !slotptr(rppage, idx)->dead ) { - bt_putid (slotptr(rppage, idx)->id, page_no); - break; - } - - if( idx > rppage->cnt ) - return bt->err = BTERR_struct; - } - - // now that there are no more pointers to our right node - // we can wait for delete lock on it - - bt_lockpage(BtLockDelete, rset); - bt_lockpage(BtLockWrite, rset); - - // pull contents of right page into our empty page - - memcpy (page, rpage, bt->mgr->page_size); - - // ready to release right parent lock - // now that we have a new page in place - - if( ppage->act == 1 ) { - bt_unlockpage (BtLockWrite, rpset); - bt_unpinlatch (rpset); - bt_unpinpool (rppool); - } - - // 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_unlockpage(BtLockDelete, rset); - bt_unlockpage(BtLockWrite, rset); - bt_unpinlatch (rset); - bt_unpinpool (rpool); - - bt_spinreleasewrite(bt->mgr->latchmgr->lock); - - // delete our obsolete fence key from our parent - - slotptr(ppage, slot)->dead = 1; - ppage->dirty = 1; - - // if our parent now empty - // remove it from the tree - - if( ppage->act-- == 1 ) - if( bt_mergeleft (bt, ppage, ppool, pset, parent, lvl+1) ) - return bt->err; - -rmergexit: - bt_unlockpage (BtLockWrite, pset); - bt_unpinlatch (pset); - bt_unpinpool (ppool); - - bt->found = 1; - return bt->err = 0; -} - -// remove empty page from the B-tree -// try merging left first. If no left -// sibling, then merge right. - -// call with page loaded and locked, -// return with page locked. - -BTERR bt_mergeleft (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl) -{ -unsigned char fencekey[256], postkey[256]; -uint slot, idx, postfence = 0; -BtLatchSet *lset, *pset; -BtPool *lpool, *ppool; -BtPage lpage, ppage; -uid left, parent; -BtKey ptr; - - ptr = keyptr(page, page->cnt); - memcpy(fencekey, ptr, ptr->len + 1); - bt_unlockpage (BtLockWrite, set); - - // load and lock our parent - -retry: - if( !(slot = bt_loadpage (bt, fencekey+1, *fencekey, lvl+1, BtLockWrite)) ) - return bt->err; - - parent = bt->page_no; - ppage = bt->page; - ppool = bt->pool; - pset = bt->set; - - // wait until we are not a foster child - - if( bt->foster ) { - bt_unlockpage (BtLockWrite, pset); - bt_unpinlatch (pset); - bt_unpinpool (ppool); -#ifdef unix - sched_yield(); -#else - SwitchToThread(); -#endif - goto retry; - } - - // find our left neighbor in our parent page - - for( idx = slot; --idx; ) - if( !slotptr(ppage, idx)->dead ) - break; - - // if no left neighbor, do right merge - - if( !idx ) - return bt_mergeright (bt, page, pool, set, page_no, lvl, slot); - - // lock and map our left neighbor's page - - left = bt_getid (slotptr(ppage, idx)->id); - - if( lpool = bt_pinpool (bt, left) ) - lpage = bt_page (bt, lpool, left); - else - return bt->err; - - lset = bt_pinlatch (bt, left); - bt_lockpage(BtLockWrite, lset); - - // wait until foster sibling is in our parent - - if( bt_getid (lpage->right) != page_no ) { - bt_unlockpage (BtLockWrite, pset); - bt_unpinlatch (pset); - bt_unpinpool (ppool); - bt_unlockpage (BtLockWrite, lset); - bt_unpinlatch (lset); - bt_unpinpool (lpool); -#ifdef linux - sched_yield(); -#else - SwitchToThread(); -#endif - goto retry; - } - - // since our page will have no more pointers to it, - // obtain Delete lock and wait for write locks to clear - - bt_lockpage(BtLockDelete, set); - bt_lockpage(BtLockWrite, set); - - // if we aren't dead yet, - // get ready for exit - - if( page->act ) { - bt_unlockpage(BtLockDelete, set); - bt_unlockpage(BtLockWrite, lset); - bt_unpinlatch (lset); - bt_unpinpool (lpool); - goto lmergexit; - } - - // are we are the fence key for our parent? - // if so, grab our old fence key - - if( postfence = slot == ppage->cnt ) { - ptr = keyptr (ppage, ppage->cnt); - memcpy(fencekey, ptr, ptr->len + 1); - memset(slotptr(ppage, ppage->cnt), 0, sizeof(BtSlot)); - - // clear out other dead slots - - while( --ppage->cnt ) - if( slotptr(ppage, ppage->cnt)->dead ) - memset(slotptr(ppage, ppage->cnt), 0, sizeof(BtSlot)); - else - break; - - ptr = keyptr (ppage, ppage->cnt); - memcpy(postkey, ptr, ptr->len + 1); - } else - slotptr(ppage,slot)->dead = 1; - - ppage->dirty = 1; - ppage->act--; - - // push our right neighbor pointer to our left - - memcpy (lpage->right, page->right, BtId); - - // add ourselves to free chain - // lock latch mgr - - bt_spinwritelock(bt->mgr->latchmgr->lock); - - // store free chain in allocation page second right - bt_putid(page->right, bt_getid(bt->mgr->latchmgr->alloc[1].right)); - bt_putid(bt->mgr->latchmgr->alloc[1].right, page_no); - - // unlock latch mgr and pages - - bt_spinreleasewrite(bt->mgr->latchmgr->lock); - bt_unlockpage(BtLockWrite, lset); - bt_unpinlatch (lset); - bt_unpinpool (lpool); - - // release our node's delete lock - - bt_unlockpage(BtLockDelete, set); - -lmergexit: - bt_unlockpage (BtLockWrite, pset); - bt_unpinpool (ppool); - - // do we need to post parent's fence key in its parent? - - if( !postfence || parent == ROOT_page ) { - bt_unpinlatch (pset); - bt->found = 1; - return bt->err = 0; - } - - // interlock parent fence post - - bt_lockpage (BtLockParent, pset); - - // load parent's parent page -posttry: - if( !(slot = bt_loadpage (bt, fencekey+1, *fencekey, lvl+2, BtLockWrite)) ) - return bt->err; - - if( !(slot = bt_cleanpage (bt, bt->page, *fencekey, slot)) ) - if( bt_splitpage (bt, bt->page, bt->pool, bt->set, bt->page_no) ) - return bt->err; - else - goto posttry; - - page = bt->page; - - page->min -= *postkey + 1; - ((unsigned char *)page)[page->min] = *postkey; - memcpy ((unsigned char *)page + page->min +1, postkey + 1, *postkey ); - slotptr(page, slot)->off = page->min; - - bt_unlockpage (BtLockParent, pset); - bt_unpinlatch (pset); - - bt_unlockpage (BtLockWrite, bt->set); - bt_unpinlatch (bt->set); - bt_unpinpool (bt->pool); - - bt->found = 1; - return bt->err = 0; -} - -// find and delete key on page by marking delete flag bit -// if page becomes empty, delete it from the btree - -BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len) -{ -BtLatchSet *set; -BtPool *pool; -BtPage page; -uid page_no; -BtKey ptr; -uint slot; - - if( !(slot = bt_loadpage (bt, key, len, 0, BtLockWrite)) ) - return bt->err; - - page_no = bt->page_no; - page = bt->page; - pool = bt->pool; - set = bt->set; - - // if key is found delete it, otherwise ignore request - - ptr = keyptr(page, slot); - - if( bt->found = !keycmp (ptr, key, len) ) - if( bt->found = slotptr(page, slot)->dead == 0 ) { - slotptr(page,slot)->dead = 1; - if( slot < page->cnt ) - page->dirty = 1; - if( !--page->act ) - if( bt_mergeleft (bt, page, pool, set, page_no, 0) ) - return bt->err; - } - - bt_unlockpage(BtLockWrite, set); - bt_unpinlatch (set); - bt_unpinpool (pool); - return bt->err = 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, BtPage page, uint amt, uint slot) -{ -uint nxt = bt->mgr->page_size; -uint cnt = 0, idx = 0; -uint max = page->cnt; -uint newslot = max; -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 - - while( cnt++ < max ) { - if( cnt == slot ) - newslot = idx + 1; - 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, BtPage page, uint slot, unsigned char *key, uint len, uid id, uint tod) -{ -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 -// return unlocked and unpinned. - -BTERR bt_splitpage (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no) -{ -uint slot, cnt, idx, max, nxt = bt->mgr->page_size; -unsigned char fencekey[256]; -uint tod = time(NULL); -uint lvl = page->lvl; -uid new_page; -BtKey key; - - // initialize frame buffer for right node - - memset (bt->frame, 0, bt->mgr->page_size); - max = page->cnt - page->foster; - 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 ) - memcpy (bt->frame->right, page->right, BtId); - - 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--; - - bt_unlockpage (BtLockParent, set); - - // if this emptied page, - // undo the foster child - - if( !page->act ) - if( bt_mergeleft (bt, page, pool, set, page_no, lvl) ) - return bt->err; - - // unlock and unpin - - bt_unlockpage (BtLockWrite, 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, bt->page, len, slot) ) - break; - - if( bt_splitpage (bt, bt->page, bt->pool, bt->set, bt->page_no) ) - return bt->err; - } - - bt_addkeytopage (bt, bt->page, 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 - -void bt_latchaudit (BtDb *bt) -{ -ushort idx, hashidx; -BtLatchSet *set; -BtPool *pool; -BtPage page; -uid page_no; - -#ifdef unix - for( idx = 1; idx < bt->mgr->latchmgr->latchdeployed; idx++ ) { - set = bt->mgr->latchsets + idx; - if( *(ushort *)set->readwr || *(ushort *)set->access || *(ushort *)set->parent ) { - fprintf(stderr, "latchset %d locked for page %6x\n", idx, set->page_no); - *(ushort *)set->readwr = 0; - *(ushort *)set->access = 0; - *(ushort *)set->parent = 0; - } - if( set->pin ) { - fprintf(stderr, "latchset %d pinned\n", idx); - set->pin = 0; - } - } - - for( hashidx = 0; hashidx < bt->mgr->latchmgr->latchhash; hashidx++ ) { - 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( *(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); - if( set->pin ) - fprintf(stderr, "latchset %d pinned\n", idx); - } while( idx = set->next ); - } - page_no = bt_getid(bt->mgr->latchmgr->alloc[1].right); - - while( page_no ) { - fprintf(stderr, "free: %.6x\n", (uint)page_no); - pool = bt_pinpool (bt, page_no); - page = bt_page (bt, pool, page_no); - page_no = bt_getid(page->right); - bt_unpinpool (pool); - } -#endif -} - -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 'a': - fprintf(stderr, "started latch mgr audit\n"); - 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") ) - 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 diff --git a/fosterbtreeg.c b/fosterbtreeg.c deleted file mode 100644 index e43f576..0000000 --- a/fosterbtreeg.c +++ /dev/null @@ -1,2770 +0,0 @@ -// foster btree version g -// 29 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 -#include -#define SYS_futex 202 -#endif - -#ifdef unix -#include -#include -#include -#include -#include -#include -#include -#include -#include -#else -#define WIN32_LEAN_AND_MEAN -#include -#include -#include -#include -#include -#include -#include -#endif - -#include -#include - -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 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; - -// hash table entries - -typedef struct { - BtLatch latch[1]; - volatile ushort slot; // Latch table entry at head of chain -} BtHashEntry; - -// latch manager table structure - -typedef struct { - 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 - 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 - 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 - 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; -#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 - 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 - 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 foster; // last search was to foster child - 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); - -// internal functions -BTERR bt_splitpage (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no); -uint bt_cleanpage(BtDb *bt, BtPage page, uint amt, uint slot); -BTERR bt_mergeleft (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl); - -// 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; -} - -// 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(BtLatch *latch, int private) -{ -uint prev; - - if( private ) - private = FUTEX_PRIVATE_FLAG; - - while( 1 ) { - // obtain latch mutex - if( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex ) { - sched_yield(); - continue; - } - - // wait for writers to clear - // increment read waiters and wait - - 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 - - __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(BtLatch *latch, int private) -{ -uint prev; - - if( private ) - private = FUTEX_PRIVATE_FLAG; - - while( 1 ) { - // obtain latch mutex - if( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex ) { - sched_yield(); - continue; - } - - // 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(BtLatch *latch) -{ -int ans; - - // try for mutex, - // abandon request if not taken - - if( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex ) - return 0; - - // see if write mode is available - - 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 lock - -void bt_spinreleasewrite(BtLatch *latch, int private) -{ - 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(BtLatch *latch, int private) -{ - 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 - -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; -} - -// release latch pin - -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, 0); - - 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, 0); - - if( slot ) - return set; - - // try again, this time with write lock - - bt_spinwritelock(bt->mgr->latchmgr->table[hashidx].latch, 0); - - 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, 0); - 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_latchlink (bt, hashidx, victim, page_no); - bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch, 0); - 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, 0); - continue; - } - - if( set->pin ) { - bt_spinreleasewrite (set->busy, 0); - bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch, 0); - 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, 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, 0); - bt_spinreleasewrite (set->busy, 0); - 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); -#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), 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(BtLatch)); -#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(BtLatch)); -#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); - - 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; -} - -// 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; -#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)); - 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], 1); - - // 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], 1); - pool->lru++; - return pool; - } - - // upgrade to write lock - - bt_spinreleaseread (&bt->mgr->latch[idx], 1); - bt_spinwritelock (&bt->mgr->latch[idx], 1); - - // 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], 1); - 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], 1); - 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], 1); - 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], 1); - - // 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], 1); - 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_spinreadlock (set->readwr, 0); - break; - case BtLockWrite: - bt_spinwritelock (set->readwr, 0); - break; - case BtLockAccess: - bt_spinreadlock (set->access, 0); - break; - case BtLockDelete: - bt_spinwritelock (set->access, 0); - break; - case BtLockParent: - bt_spinwritelock (set->parent, 0); - break; - } -} - -// remove write, read, or parent lock on requested page_no. - -void bt_unlockpage(BtLock mode, BtLatchSet *set) -{ - switch( mode ) { - case BtLockRead: - bt_spinreleaseread (set->readwr, 0); - break; - case BtLockWrite: - bt_spinreleasewrite (set->readwr, 0); - break; - case BtLockAccess: - bt_spinreleaseread (set->access, 0); - break; - case BtLockDelete: - bt_spinreleasewrite (set->access, 0); - break; - case BtLockParent: - bt_spinreleasewrite (set->parent, 0); - 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, 0); - - // 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, 0); - - 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, 0); - - // 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; -uint good = 0; - - // if no right link - // make stopper key an infinite fence value - // by setting the good flag - - if( bt_getid (bt->page->right) ) - higher++; - else - good++; - - // low is the next candidate. - // loop ends when they meet - - // if good, higher is already - // tested as .ge. the given key. - - while( diff = higher - low ) { - slot = low + ( diff >> 1 ); - if( keycmp (keyptr(bt->page, slot), key, len) < 0 ) - low = slot + 1; - else - higher = slot, good++; - } - - // 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 - -uint 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; -int foster = 0; - - // 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; - } - } - - // find key on page at this level - // and either descend to requested level - // or return key slot - - if( 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 bt->foster = foster, slot; - - // find next active slot - // note: foster children are never dead - - while( slotptr(bt->page, slot)->dead ) - if( slot++ < bt->page->cnt ) - continue; - else { - // we are waiting for fence key posting - page_no = bt_getid(bt->page->right); - goto slideright; - } - - // is this slot < foster child area - // if so, drill to next level - - if( slot <= bt->page->cnt - bt->page->foster ) - foster = 0, drill--; - else - foster = 1; - - // continue right onto foster child - // or down to next level. - - page_no = bt_getid(slotptr(bt->page, slot)->id); - - // or slide right into next page - - } else { - page_no = bt_getid(bt->page->right); - foster = 1; - } - -slideright: - prevpage = bt->page_no; - prevpool = bt->pool; - prevset = bt->set; - prevmode = mode; - - } while( page_no ); - - // return error on end of chain - - bt->err = BTERR_struct; - return 0; // return error -} - -// remove empty page from the B-tree -// by pulling our right node left over ourselves - -// call with bt->page, etc, set to page's locked parent -// returns with page locked. - -BTERR bt_mergeright (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl, uint slot) -{ -BtLatchSet *rset, *pset, *rpset; -BtPool *rpool, *ppool, *rppool; -BtPage rpage, ppage, rppage; -uid right, parent, rparent; -BtKey ptr; -uint idx; - - // cache node's parent page - - parent = bt->page_no; - ppage = bt->page; - ppool = bt->pool; - pset = bt->set; - - // lock and map our right page - // note that it cannot be our foster child - // since the our node is empty - // and it cannot be NULL because of the stopper - // in the last right page - - bt_lockpage (BtLockWrite, set); - - // if we aren't dead yet - - if( page->act ) - goto rmergexit; - - if( right = bt_getid (page->right) ) - if( rpool = bt_pinpool (bt, right) ) - rpage = bt_page (bt, rpool, right); - else - return bt->err; - else - return bt->err = BTERR_struct; - - rset = bt_pinlatch (bt, right); - - // find our right neighbor - - if( ppage->act > 1 ) { - for( idx = slot; idx++ < ppage->cnt; ) - if( !slotptr(ppage, idx)->dead ) - break; - - if( idx > ppage->cnt ) - return bt->err = BTERR_struct; - - // redirect right neighbor in parent to left node - - bt_putid(slotptr(ppage,idx)->id, page_no); - } - - // if parent has only our deleted page, e.g. no right neighbor - // prepare to merge parent itself - - if( ppage->act == 1 ) { - if( rparent = bt_getid (ppage->right) ) - if( rppool = bt_pinpool (bt, rparent) ) - rppage = bt_page (bt, rppool, rparent); - else - return bt->err; - else - return bt->err = BTERR_struct; - - rpset = bt_pinlatch (bt, rparent); - bt_lockpage (BtLockWrite, rpset); - - // find our right neighbor on right parent page - - for( idx = 0; idx++ < rppage->cnt; ) - if( !slotptr(rppage, idx)->dead ) { - bt_putid (slotptr(rppage, idx)->id, page_no); - break; - } - - if( idx > rppage->cnt ) - return bt->err = BTERR_struct; - } - - // now that there are no more pointers to our right node - // we can wait for delete lock on it - - bt_lockpage(BtLockDelete, rset); - bt_lockpage(BtLockWrite, rset); - - // pull contents of right page into our empty page - - memcpy (page, rpage, bt->mgr->page_size); - - // ready to release right parent lock - // now that we have a new page in place - - if( ppage->act == 1 ) { - bt_unlockpage (BtLockWrite, rpset); - bt_unpinlatch (rpset); - bt_unpinpool (rppool); - } - - // add killed right block to free chain - // lock latch mgr - - 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)); - bt_putid(bt->mgr->latchmgr->alloc[1].right, right); - - // unlock latch mgr and right page - - bt_unlockpage(BtLockDelete, rset); - bt_unlockpage(BtLockWrite, rset); - bt_unpinlatch (rset); - bt_unpinpool (rpool); - - bt_spinreleasewrite(bt->mgr->latchmgr->lock, 0); - - // delete our obsolete fence key from our parent - - slotptr(ppage, slot)->dead = 1; - ppage->dirty = 1; - - // if our parent now empty - // remove it from the tree - - if( ppage->act-- == 1 ) - if( bt_mergeleft (bt, ppage, ppool, pset, parent, lvl+1) ) - return bt->err; - -rmergexit: - bt_unlockpage (BtLockWrite, pset); - bt_unpinlatch (pset); - bt_unpinpool (ppool); - - bt->found = 1; - return bt->err = 0; -} - -// remove empty page from the B-tree -// try merging left first. If no left -// sibling, then merge right. - -// call with page loaded and locked, -// return with page locked. - -BTERR bt_mergeleft (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl) -{ -unsigned char fencekey[256], postkey[256]; -uint slot, idx, postfence = 0; -BtLatchSet *lset, *pset; -BtPool *lpool, *ppool; -BtPage lpage, ppage; -uid left, parent; -BtKey ptr; - - ptr = keyptr(page, page->cnt); - memcpy(fencekey, ptr, ptr->len + 1); - bt_unlockpage (BtLockWrite, set); - - // load and lock our parent - -retry: - if( !(slot = bt_loadpage (bt, fencekey+1, *fencekey, lvl+1, BtLockWrite)) ) - return bt->err; - - parent = bt->page_no; - ppage = bt->page; - ppool = bt->pool; - pset = bt->set; - - // wait until we are not a foster child - - if( bt->foster ) { - bt_unlockpage (BtLockWrite, pset); - bt_unpinlatch (pset); - bt_unpinpool (ppool); -#ifdef unix - sched_yield(); -#else - SwitchToThread(); -#endif - goto retry; - } - - // find our left neighbor in our parent page - - for( idx = slot; --idx; ) - if( !slotptr(ppage, idx)->dead ) - break; - - // if no left neighbor, do right merge - - if( !idx ) - return bt_mergeright (bt, page, pool, set, page_no, lvl, slot); - - // lock and map our left neighbor's page - - left = bt_getid (slotptr(ppage, idx)->id); - - if( lpool = bt_pinpool (bt, left) ) - lpage = bt_page (bt, lpool, left); - else - return bt->err; - - lset = bt_pinlatch (bt, left); - bt_lockpage(BtLockWrite, lset); - - // wait until foster sibling is in our parent - - if( bt_getid (lpage->right) != page_no ) { - bt_unlockpage (BtLockWrite, pset); - bt_unpinlatch (pset); - bt_unpinpool (ppool); - bt_unlockpage (BtLockWrite, lset); - bt_unpinlatch (lset); - bt_unpinpool (lpool); -#ifdef linux - sched_yield(); -#else - SwitchToThread(); -#endif - goto retry; - } - - // since our page will have no more pointers to it, - // obtain Delete lock and wait for write locks to clear - - bt_lockpage(BtLockDelete, set); - bt_lockpage(BtLockWrite, set); - - // if we aren't dead yet, - // get ready for exit - - if( page->act ) { - bt_unlockpage(BtLockDelete, set); - bt_unlockpage(BtLockWrite, lset); - bt_unpinlatch (lset); - bt_unpinpool (lpool); - goto lmergexit; - } - - // are we are the fence key for our parent? - // if so, grab our old fence key - - if( postfence = slot == ppage->cnt ) { - ptr = keyptr (ppage, ppage->cnt); - memcpy(fencekey, ptr, ptr->len + 1); - memset(slotptr(ppage, ppage->cnt), 0, sizeof(BtSlot)); - - // clear out other dead slots - - while( --ppage->cnt ) - if( slotptr(ppage, ppage->cnt)->dead ) - memset(slotptr(ppage, ppage->cnt), 0, sizeof(BtSlot)); - else - break; - - ptr = keyptr (ppage, ppage->cnt); - memcpy(postkey, ptr, ptr->len + 1); - } else - slotptr(ppage,slot)->dead = 1; - - ppage->dirty = 1; - ppage->act--; - - // push our right neighbor pointer to our left - - memcpy (lpage->right, page->right, BtId); - - // add ourselves to free chain - // lock latch mgr - - bt_spinwritelock(bt->mgr->latchmgr->lock, 0); - - // store free chain in allocation page second right - bt_putid(page->right, bt_getid(bt->mgr->latchmgr->alloc[1].right)); - bt_putid(bt->mgr->latchmgr->alloc[1].right, page_no); - - // unlock latch mgr and pages - - bt_spinreleasewrite(bt->mgr->latchmgr->lock, 0); - bt_unlockpage(BtLockWrite, lset); - bt_unpinlatch (lset); - bt_unpinpool (lpool); - - // release our node's delete lock - - bt_unlockpage(BtLockDelete, set); - -lmergexit: - bt_unlockpage (BtLockWrite, pset); - bt_unpinpool (ppool); - - // do we need to post parent's fence key in its parent? - - if( !postfence || parent == ROOT_page ) { - bt_unpinlatch (pset); - bt->found = 1; - return bt->err = 0; - } - - // interlock parent fence post - - bt_lockpage (BtLockParent, pset); - - // load parent's parent page -posttry: - if( !(slot = bt_loadpage (bt, fencekey+1, *fencekey, lvl+2, BtLockWrite)) ) - return bt->err; - - if( !(slot = bt_cleanpage (bt, bt->page, *fencekey, slot)) ) - if( bt_splitpage (bt, bt->page, bt->pool, bt->set, bt->page_no) ) - return bt->err; - else - goto posttry; - - page = bt->page; - - page->min -= *postkey + 1; - ((unsigned char *)page)[page->min] = *postkey; - memcpy ((unsigned char *)page + page->min +1, postkey + 1, *postkey ); - slotptr(page, slot)->off = page->min; - - bt_unlockpage (BtLockParent, pset); - bt_unpinlatch (pset); - - bt_unlockpage (BtLockWrite, bt->set); - bt_unpinlatch (bt->set); - bt_unpinpool (bt->pool); - - bt->found = 1; - return bt->err = 0; -} - -// find and delete key on page by marking delete flag bit -// if page becomes empty, delete it from the btree - -BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len) -{ -BtLatchSet *set; -BtPool *pool; -BtPage page; -uid page_no; -BtKey ptr; -uint slot; - - if( !(slot = bt_loadpage (bt, key, len, 0, BtLockWrite)) ) - return bt->err; - - page_no = bt->page_no; - page = bt->page; - pool = bt->pool; - set = bt->set; - - // if key is found delete it, otherwise ignore request - - ptr = keyptr(page, slot); - - if( bt->found = !keycmp (ptr, key, len) ) - if( bt->found = slotptr(page, slot)->dead == 0 ) { - slotptr(page,slot)->dead = 1; - if( slot < page->cnt ) - page->dirty = 1; - if( !--page->act ) - if( bt_mergeleft (bt, page, pool, set, page_no, 0) ) - return bt->err; - } - - bt_unlockpage(BtLockWrite, set); - bt_unpinlatch (set); - bt_unpinpool (pool); - return bt->err = 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, BtPage page, uint amt, uint slot) -{ -uint nxt = bt->mgr->page_size; -uint cnt = 0, idx = 0; -uint max = page->cnt; -uint newslot = max; -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 - - while( cnt++ < max ) { - if( cnt == slot ) - newslot = idx + 1; - 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, BtPage page, uint slot, unsigned char *key, uint len, uid id, uint tod) -{ -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 -// return unlocked and unpinned. - -BTERR bt_splitpage (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no) -{ -uint slot, cnt, idx, max, nxt = bt->mgr->page_size; -unsigned char fencekey[256]; -uint tod = time(NULL); -uint lvl = page->lvl; -uid new_page; -BtKey key; - - // initialize frame buffer for right node - - memset (bt->frame, 0, bt->mgr->page_size); - max = page->cnt - page->foster; - 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 ) - memcpy (bt->frame->right, page->right, BtId); - - 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--; - - bt_unlockpage (BtLockParent, set); - - // if this emptied page, - // undo the foster child - - if( !page->act ) - if( bt_mergeleft (bt, page, pool, set, page_no, lvl) ) - return bt->err; - - // unlock and unpin - - bt_unlockpage (BtLockWrite, 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, bt->page, len, slot) ) - break; - - if( bt_splitpage (bt, bt->page, bt->pool, bt->set, bt->page_no) ) - return bt->err; - } - - bt_addkeytopage (bt, bt->page, 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 - -void bt_latchaudit (BtDb *bt) -{ -ushort idx, hashidx; -BtLatchSet *set; -BtPool *pool; -BtPage page; -uid page_no; - -#ifdef unix - for( idx = 1; idx < bt->mgr->latchmgr->latchdeployed; idx++ ) { - set = bt->mgr->latchsets + idx; - if( *(ushort *)set->readwr || *(ushort *)set->access || *(ushort *)set->parent ) { - fprintf(stderr, "latchset %d locked for page %6x\n", idx, set->page_no); - *(ushort *)set->readwr = 0; - *(ushort *)set->access = 0; - *(ushort *)set->parent = 0; - } - if( set->pin ) { - fprintf(stderr, "latchset %d pinned\n", idx); - set->pin = 0; - } - } - - for( hashidx = 0; hashidx < bt->mgr->latchmgr->latchhash; hashidx++ ) { - 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( *(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); - if( set->pin ) - fprintf(stderr, "latchset %d pinned\n", idx); - } while( idx = set->next ); - } - page_no = bt_getid(bt->mgr->latchmgr->alloc[1].right); - - while( page_no ) { - fprintf(stderr, "free: %.6x\n", (uint)page_no); - pool = bt_pinpool (bt, page_no); - page = bt_page (bt, pool, page_no); - page_no = bt_getid(page->right); - bt_unpinpool (pool); - } -#endif -} - -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 'a': - fprintf(stderr, "started latch mgr audit\n"); - 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") ) - 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 -- 2.40.0