// foster btree version e
-// 30 DEC 2013
+// 29 JAN 2014
// author: karl malbrain, malbrain@cal.berkeley.edu
// the tod field from the key.
// Keys are marked dead, but remain on the page until
-// it cleanup is called. The fence key (highest key) for
+// cleanup is called. The fence key (highest key) for
// the page is always present, even after cleanup.
typedef struct {
// by the BtSlot array of keys.
typedef struct Page {
- uint cnt; // count of keys in page
- uint act; // count of active keys
- uint min; // next key offset
- uint foster; // count of foster children
+ 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:6; // level of page
- unsigned char kill:1; // page is being deleted
+ 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;
volatile ushort slot; // Latch table entry at head of chain
} BtHashEntry;
-// latch table lock structure
-// implements a fair read-write lock
+// latch manager table structure
typedef struct {
#ifdef unix
uint mode; // read-write mode
#ifdef unix
int idx;
- char *pooladvise; // bit maps for pool page advisements
#else
HANDLE idx;
#endif
ushort poolcnt; // highest page pool node in use
ushort poolmax; // highest page pool node allocated
- ushort poolmask; // total size of pages in mmap segment - 1
+ ushort 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 *latchset; // first mapped latch set from latch pages
+ BtLatchSet *latchsets; // mapped latch set from latch pages
#ifndef unix
- HANDLE halloc, hlatch; // allocation and latch table handles
+ HANDLE halloc; // allocation and latch table handle
#endif
} BtMgr;
typedef struct {
BtMgr *mgr; // buffer manager for thread
- BtPage temp; // temporary frame buffer (memory mapped/file IO)
BtPage cursor; // cached frame for start/next (never mapped)
BtPage frame; // spare frame for the page split (never mapped)
BtPage zero; // page frame for zeroes at end of file
BtPage page; // current page
uid page_no; // current page number
uid cursor_page; // current cursor page number
+ BtLatchSet *set; // current page latch set
+ 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;
// B-Tree functions
extern void bt_close (BtDb *bt);
extern BtDb *bt_open (BtMgr *mgr);
-extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod);
-extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
+extern 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);
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);
do {
#ifdef unix
- do prev = __sync_fetch_and_or((ushort *)latch, Mutex);
- while( prev & Mutex );
+ while( __sync_fetch_and_or((ushort *)latch, Mutex) & Mutex )
+ sched_yield();
#else
- do prev = _InterlockedOr16((ushort *)latch, Mutex);
- while( prev & Mutex );
+ while( _InterlockedOr16((ushort *)latch, Mutex) & Mutex )
+ SwitchToThread();
#endif
- // see if exclusive request is pending, or granted
+ // see if exclusive request is granted or pending
if( prev = !(latch->exclusive | latch->pending) )
- latch->share++;
-
- latch->mutex = 0;
+#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
void bt_spinwritelock(BtSpinLatch *latch)
{
-ushort prev;
-
do {
-#ifdef unix
- do prev = __sync_fetch_and_or((ushort *)latch, (Pending | Mutex));
- while( prev & Mutex );
+#ifdef unix
+ while( __sync_fetch_and_or((ushort *)latch, Mutex | Pending) & Mutex )
+ sched_yield();
#else
- do prev = _InterlockedOr16((ushort *)latch, (Pending | Mutex));
- while( prev & Mutex );
+ 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
- if( prev = !(latch->share | latch->exclusive) )
- latch->exclusive = 1, latch->pending = 0;
-
- latch->mutex = 0;
-
- if( prev )
return;
+ }
+
+#ifdef unix
+ __sync_fetch_and_and ((ushort *)latch, ~Mutex);
+#else
+ _InterlockedAnd16((ushort *)latch, ~Mutex);
+#endif
#ifdef unix
sched_yield();
#else
ushort prev;
#ifdef unix
- do prev = __sync_fetch_and_or((ushort *)latch, Mutex);
- while( prev & Mutex );
+ if( prev = __sync_fetch_and_or((ushort *)latch, Mutex), prev & Mutex )
+ return 0;
#else
- do prev = _InterlockedOr16((ushort *)latch, Mutex);
- while( prev & Mutex );
+ if( prev = _InterlockedOr16((ushort *)latch, Mutex), prev & Mutex )
+ return 0;
#endif
// take write access if all bits are clear
if( !prev )
- latch->exclusive = 1;
+#ifdef unix
+ __sync_fetch_and_or ((ushort *)latch, Write);
+#else
+ _InterlockedOr16((ushort *)latch, Write);
+#endif
- latch->mutex = 0;
+#ifdef unix
+ __sync_fetch_and_and ((ushort *)latch, ~Mutex);
+#else
+ _InterlockedAnd16((ushort *)latch, ~Mutex);
+#endif
return !prev;
}
void bt_spinreleasewrite(BtSpinLatch *latch)
{
-ushort prev;
-
#ifdef unix
- do prev = __sync_fetch_and_or((ushort *)latch, Mutex);
- while( prev & Mutex );
+ __sync_fetch_and_and ((ushort *)latch, ~Write);
#else
- do prev = _InterlockedOr16((ushort *)latch, Mutex);
- while( prev & Mutex );
+ _InterlockedAnd16((ushort *)latch, ~Write);
#endif
-
- latch->exclusive = 0;
- latch->mutex = 0;
}
// decrement reader count
void bt_spinreleaseread(BtSpinLatch *latch)
{
-ushort prev;
-
#ifdef unix
- do prev = __sync_fetch_and_or((ushort *)latch, Mutex);
- while( prev & Mutex );
+ __sync_fetch_and_add((ushort *)latch, -Share);
#else
- do prev = _InterlockedOr16((ushort *)latch, Mutex);
- while( prev & Mutex );
+ _InterlockedExchangeAdd16 ((ushort *)latch, -Share);
#endif
-
- latch->share--;
- latch->mutex = 0;
}
-void bt_initlockset (BtLatchSet *set)
+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);
void bt_latchlink (BtDb *bt, ushort hashidx, ushort victim, uid page_no)
{
-BtLatchSet *set = bt->mgr->latchset + victim;
+BtLatchSet *set = bt->mgr->latchsets + victim;
if( set->next = bt->mgr->latchmgr->table[hashidx].slot )
- bt->mgr->latchset[set->next].prev = victim;
+ bt->mgr->latchsets[set->next].prev = victim;
bt->mgr->latchmgr->table[hashidx].slot = victim;
set->page_no = page_no;
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_bindlatch (BtDb *bt, uid page_no, int incr)
+BtLatchSet *bt_pinlatch (BtDb *bt, uid page_no)
{
ushort hashidx = page_no % bt->mgr->latchmgr->latchhash;
ushort slot, avail = 0, victim, idx;
if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
{
- set = bt->mgr->latchset + slot;
+ set = bt->mgr->latchsets + slot;
if( page_no == set->page_no )
break;
} while( slot = set->next );
- if( slot && incr ) {
+ if( slot ) {
#ifdef unix
__sync_fetch_and_add(&set->pin, 1);
#else
if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
{
- set = bt->mgr->latchset + slot;
+ set = bt->mgr->latchsets + slot;
if( page_no == set->page_no )
break;
if( !set->pin && !avail )
// found our entry, or take over an unpinned one
if( slot || (slot = avail) ) {
- set = bt->mgr->latchset + slot;
- if( incr )
+ set = bt->mgr->latchsets + slot;
#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
+ __sync_fetch_and_add(&set->pin, 1);
#else
- _InterlockedIncrement16 (&set->pin);
+ _InterlockedIncrement16 (&set->pin);
#endif
set->page_no = page_no;
bt_spinreleasewrite(bt->mgr->latchmgr->table[hashidx].latch);
#endif
if( victim < bt->mgr->latchmgr->latchtotal ) {
- set = bt->mgr->latchset + victim;
- if( incr )
+ set = bt->mgr->latchsets + victim;
#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
+ __sync_fetch_and_add(&set->pin, 1);
#else
- _InterlockedIncrement16 (&set->pin);
+ _InterlockedIncrement16 (&set->pin);
#endif
- bt_initlockset (set);
+ bt_initlockset (set, 0);
bt_latchlink (bt, hashidx, victim, page_no);
bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch);
return set;
// we don't use slot zero
if( victim %= bt->mgr->latchmgr->latchtotal )
- set = bt->mgr->latchset + victim;
+ set = bt->mgr->latchsets + victim;
else
continue;
// unlink our available victim from its hash chain
if( set->prev )
- bt->mgr->latchset[set->prev].next = set->next;
+ bt->mgr->latchsets[set->prev].next = set->next;
else
bt->mgr->latchmgr->table[idx].slot = set->next;
if( set->next )
- bt->mgr->latchset[set->next].prev = set->prev;
+ bt->mgr->latchsets[set->next].prev = set->prev;
bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch);
-
- if( incr )
#ifdef unix
- __sync_fetch_and_add(&set->pin, 1);
+ __sync_fetch_and_add(&set->pin, 1);
#else
- _InterlockedIncrement16 (&set->pin);
+ _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);
#endif
}
+#ifdef unix
+ munmap (mgr->latchsets, mgr->latchmgr->nlatchpage * mgr->page_size);
+ munmap (mgr->latchmgr, mgr->page_size);
+#else
+ FlushViewOfFile(mgr->latchmgr, 0);
+ UnmapViewOfFile(mgr->latchmgr);
+ CloseHandle(mgr->halloc);
+#endif
#ifdef unix
close (mgr->idx);
free (mgr->pool);
free (mgr->hash);
free (mgr->latch);
- free (mgr->pooladvise);
free (mgr);
#else
FlushFileBuffers(mgr->idx);
uint lvl, attr, cacheblk, last, slot, idx;
uint nlatchpage, latchhash;
BtLatchMgr *latchmgr;
-int lockmode;
off64_t size;
uint amt[1];
BtMgr* mgr;
#ifdef unix
mgr = calloc (1, sizeof(BtMgr));
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
- lockmode = 1;
- break;
+ mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
- case BT_ro:
- default:
- mgr->idx = open ((char*)name, O_RDONLY);
- lockmode = 0;
- break;
- }
if( mgr->idx == -1 )
return free(mgr), NULL;
#else
mgr = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtMgr));
attr = FILE_ATTRIBUTE_NORMAL;
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
- lockmode = 1;
- break;
+ mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
- case BT_ro:
- default:
- mgr->idx = CreateFile(name, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, attr, NULL);
- lockmode = 0;
- break;
- }
if( mgr->idx == INVALID_HANDLE_VALUE )
return GlobalFree(mgr), NULL;
else
return free(mgr), free(latchmgr), NULL;
} else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
+ return free(latchmgr), free (mgr), NULL;
#else
latchmgr = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
size = GetFileSize(mgr->idx, amt);
mgr->pool = calloc (poolmax, sizeof(BtPool));
mgr->hash = calloc (hashsize, sizeof(ushort));
mgr->latch = calloc (hashsize, sizeof(BtSpinLatch));
- mgr->pooladvise = calloc (poolmax, (mgr->poolmask + 8) / 8);
#else
mgr->pool = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, poolmax * sizeof(BtPool));
mgr->hash = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(ushort));
#ifdef unix
if( write (mgr->idx, latchmgr, mgr->page_size) < mgr->page_size )
- return bt_mgrclose (mgr), NULL;
+ return free(latchmgr), bt_mgrclose (mgr), NULL;
#else
if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
return bt_mgrclose (mgr), NULL;
mgrlatch:
#ifdef unix
- flag = PROT_READ | ( mgr->mode == BT_ro ? 0 : PROT_WRITE );
+ 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->latchset = (BtLatchSet *)mmap (0, mgr->latchmgr->nlatchpage * mgr->page_size, flag, MAP_SHARED, mgr->idx, LATCH_page * mgr->page_size);
- if( mgr->latchset == MAP_FAILED )
+ 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 = ( mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
- mgr->halloc = CreateFileMapping(mgr->idx, NULL, flag, 0, mgr->page_size, NULL);
+ 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 = ( mgr->mode == BT_ro ? FILE_MAP_READ : FILE_MAP_WRITE );
- mgr->latchmgr = MapViewOfFile(mgr->halloc, flag, 0, ALLOC_page * mgr->page_size, mgr->page_size);
+ 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 bt_mgrclose (mgr), NULL;
- flag = ( mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
- mgr->hlatch = CreateFileMapping(mgr->idx, NULL, flag, 0, (mgr->latchmgr->nlatchpage + LATCH_page) * mgr->page_size, NULL);
- if( !mgr->hlatch )
- return bt_mgrclose (mgr), NULL;
+ return GetLastError(), bt_mgrclose (mgr), NULL;
- flag = ( mgr->mode == BT_ro ? FILE_MAP_READ : FILE_MAP_WRITE );
- mgr->latchset = MapViewOfFile(mgr->halloc, flag, 0, LATCH_page * mgr->page_size, mgr->page_size * mgr->latchmgr->nlatchpage);
- if( !mgr->latchmgr )
- return bt_mgrclose (mgr), NULL;
+ mgr->latchsets = (void *)((char *)mgr->latchmgr + LATCH_page * mgr->page_size);
#endif
#ifdef unix
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;
}
pool->map = mmap (0, (bt->mgr->poolmask+1) << bt->mgr->page_bits, flag, MAP_SHARED, bt->mgr->idx, off);
if( pool->map == MAP_FAILED )
return bt->err = BTERR_map;
- // clear out madvise issued bits
- memset (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8) / 8), 0, (bt->mgr->poolmask + 8)/8);
#else
flag = ( bt->mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
pool->hmap = CreateFileMapping(bt->mgr->idx, NULL, flag, (DWORD)(limit >> 32), (DWORD)limit, NULL);
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_pinpage(BtDb *bt, uid page_no)
+BtPool *bt_pinpool(BtDb *bt, uid page_no)
{
BtPool *pool, *node, *next;
uint slot, idx, victim;
}
// place write, read, or parent lock on requested page_no.
-// pin to buffer pool and return page pointer
+// pin to buffer pool and return latchset pointer
-BTERR bt_lockpage(BtDb *bt, uid page_no, BtLock mode, BtPage *pageptr)
+void bt_lockpage(BtLock mode, BtLatchSet *set)
{
-BtLatchSet *set;
-BtPool *pool;
-uint subpage;
-BtPage page;
-
- // find/create maping in pool table
- // and pin our pool slot
-
- if( pool = bt_pinpage(bt, page_no) )
- subpage = (uint)(page_no & bt->mgr->poolmask); // page within mapping
- else
- return bt->err;
-
- if( !(set = bt_bindlatch (bt, page_no, 1)) )
- return bt->err;
-
- page = (BtPage)(pool->map + (subpage << bt->mgr->page_bits));
-
-#ifdef unix
- {
- uint idx = subpage / 8;
- uint bit = subpage % 8;
-
- if( mode == BtLockRead || mode == BtLockWrite )
- if( ~((bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] >> bit) & 1 ) {
- madvise (page, bt->mgr->page_size, MADV_WILLNEED);
- (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] |= 1 << bit;
- }
- }
-#endif
-
switch( mode ) {
case BtLockRead:
bt_readlock (set->readwr);
case BtLockParent:
bt_writelock (set->parent);
break;
- default:
- return bt->err = BTERR_lock;
}
-
- if( pageptr )
- *pageptr = page;
-
- return bt->err = 0;
}
// remove write, read, or parent lock on requested page_no.
-BTERR bt_unlockpage(BtDb *bt, uid page_no, BtLock mode)
+void bt_unlockpage(BtLock mode, BtLatchSet *set)
{
-BtLatchSet *set;
-BtPool *pool;
-uint idx;
-
- // since page is pinned
- // it should still be in the buffer pool
- // and is in no danger of being a victim for reuse
-
- if( !(set = bt_bindlatch (bt, page_no, 0)) )
- return bt->err = BTERR_latch;
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_spinreadlock (&bt->mgr->latch[idx]);
-
- if( !(pool = bt_findpool(bt, page_no, idx)) )
- return bt->err = BTERR_hash;
-
- bt_spinreleaseread (&bt->mgr->latch[idx]);
-
switch( mode ) {
case BtLockRead:
bt_releaseread (set->readwr);
case BtLockParent:
bt_releasewrite (set->parent);
break;
- default:
- return bt->err = BTERR_lock;
}
-
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, -1);
- __sync_fetch_and_add (&set->pin, -1);
-#else
- _InterlockedDecrement16 (&pool->pin);
- _InterlockedDecrement16 (&set->pin);
-#endif
- return bt->err = 0;
-}
-
-// deallocate a deleted page
-// place on free chain out of allocator page
-// fence key must already be removed from parent
-
-BTERR bt_freepage(BtDb *bt, uid page_no)
-{
- // obtain delete lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- // obtain write lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // lock allocation page
-
- bt_spinwritelock(bt->mgr->latchmgr->lock);
-
- // store free chain in allocation page second right
- bt_putid(bt->temp->right, bt_getid(bt->mgr->latchmgr->alloc[1].right));
- bt_putid(bt->mgr->latchmgr->alloc[1].right, page_no);
-
- // unlock page zero
-
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
-
- // remove write lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // remove delete lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockDelete) )
- return bt->err;
-
- return 0;
}
// allocate a new page and write page into it
uid bt_newpage(BtDb *bt, BtPage page)
{
+BtLatchSet *set;
+BtPool *pool;
uid new_page;
BtPage pmap;
int reuse;
// else allocate empty page
if( new_page = bt_getid(bt->mgr->latchmgr->alloc[1].right) ) {
- if( bt_lockpage (bt, new_page, BtLockWrite, &bt->temp) )
- return 0;
- bt_putid(bt->mgr->latchmgr->alloc[1].right, bt_getid(bt->temp->right));
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
+ 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);
reuse = 0;
}
#ifdef unix
- if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
- return bt->err = BTERR_wrt, 0;
-
// if writing first page of pool block, zero last page in the block
if ( !reuse && bt->mgr->poolmask > 0 && (new_page & bt->mgr->poolmask) == 0 )
{
// use zero buffer to write zeros
- memset(bt->zero, 0, bt->mgr->page_size);
if ( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->poolmask) << bt->mgr->page_bits) < bt->mgr->page_size )
return bt->err = BTERR_wrt, 0;
}
+
+ // unlock allocation latch
+
+ bt_spinreleasewrite(bt->mgr->latchmgr->lock);
+
+ if ( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
+ return bt->err = BTERR_wrt, 0;
+
#else
+ // unlock allocation latch
+
+ bt_spinreleasewrite(bt->mgr->latchmgr->lock);
+
// bring new page into pool and copy page.
// this will extend the file into the new pages.
+ // NB -- no latch required
- if( bt_lockpage(bt, new_page, BtLockWrite, &pmap) )
+ if( pool = bt_pinpool (bt, new_page) )
+ pmap = bt_page (bt, pool, new_page);
+ else
return 0;
memcpy(pmap, page, bt->mgr->page_size);
-
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
+ bt_unpinpool (pool);
#endif
- // unlock allocation latch and return new page no
-
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
return new_page;
}
int bt_findslot (BtDb *bt, unsigned char *key, uint len)
{
uint diff, higher = bt->page->cnt, low = 1, slot;
+uint good = 0;
+
+ // 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 lowest candidate, higher is already
- // tested as .ge. the given key, loop ends when they meet
+ // 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;
+ higher = slot, good++;
}
- return higher;
+ // return zero if key is on right link page
+
+ return good ? higher : 0;
}
// find and load page at given level for given key
// leave page rd or wr locked as requested
-int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, uint lock)
+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
// 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 )
- if( bt_lockpage(bt, page_no, BtLockAccess, NULL) )
- return 0;
+ bt_lockpage(BtLockAccess, bt->set);
- // now unlock our (possibly foster) parent
+ // now unlock and unpin our (possibly foster) parent
- if( prevpage )
- if( bt_unlockpage(bt, prevpage, prevmode) )
- return 0;
- else
- prevpage = 0;
+ if( prevpage ) {
+ bt_unlockpage(prevmode, prevset);
+ bt_unpinlatch (prevset);
+ bt_unpinpool (prevpool);
+ prevpage = 0;
+ }
// obtain read lock using lock chaining
- // and pin page contents
- if( bt_lockpage(bt, page_no, mode, &bt->page) )
- return 0;
+ bt_lockpage(mode, bt->set);
if( page_no > ROOT_page )
- if( bt_unlockpage(bt, page_no, BtLockAccess) )
- return 0;
+ bt_unlockpage(BtLockAccess, bt->set);
// re-read and re-lock root after determining actual level of root
- if( bt->page_no == ROOT_page )
+ if( page_no == ROOT_page )
if( bt->page->lvl != drill) {
drill = bt->page->lvl;
- if( lock == BtLockWrite && drill == lvl )
- if( bt_unlockpage(bt, page_no, mode) )
- return 0;
- else
- continue;
+ if( lock == BtLockWrite && drill == lvl ) {
+ bt_unlockpage(mode, bt->set);
+ bt_unpinlatch (bt->set);
+ bt_unpinpool (bt->pool);
+ continue;
+ }
}
- prevpage = bt->page_no;
- prevmode = mode;
-
- // if page is being deleted,
- // move back to preceeding page
-
- if( bt->page->kill ) {
- page_no = bt_getid (bt->page->right);
- continue;
- }
-
// find key on page at this level
- // and descend to requested level
+ // and either descend to requested level
+ // or return key slot
- slot = bt_findslot (bt, key, len);
+ if( slot = bt_findslot (bt, key, len) ) {
+ // is this slot < foster child area
+ // on the requested level?
- // is this slot a foster child?
+ // if so, return actual slot even if dead
- if( slot <= bt->page->cnt - bt->page->foster )
- if( drill == lvl )
- return slot;
+ if( slot <= bt->page->cnt - bt->page->foster )
+ if( drill == lvl )
+ return bt->foster = foster, slot;
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
+ // find next active slot
+ // note: foster children are never dead
+
+ while( slotptr(bt->page, slot)->dead )
+ if( slot++ < bt->page->cnt )
continue;
- else
+ 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;
- if( slot <= bt->page->cnt - bt->page->foster )
- drill--;
+ // continue right onto foster child
+ // or down to next level.
- // continue down / right using overlapping locks
- // to protect pages being killed or split.
+ page_no = bt_getid(slotptr(bt->page, slot)->id);
- page_no = bt_getid(slotptr(bt->page, slot)->id);
- continue;
+ // or slide right into next page
+
+ } else {
+ page_no = bt_getid(bt->page->right);
+ foster = 1;
+ }
slideright:
- page_no = bt_getid(bt->page->right);
+ prevpage = bt->page_no;
+ prevpool = bt->pool;
+ prevset = bt->set;
+ prevmode = mode;
} while( page_no );
return 0; // return error
}
-// find and delete key on page by marking delete flag bit
-// when page becomes empty, delete it from the btree
+// 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_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl)
+BTERR bt_mergeright (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl, uint slot)
{
-unsigned char leftkey[256], rightkey[256];
-uid page_no, right;
-uint slot, tod;
+BtLatchSet *rset, *pset, *rpset;
+BtPool *rpool, *ppool, *rppool;
+BtPage rpage, ppage, rppage;
+uid right, parent, rparent;
BtKey ptr;
+uint idx;
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
+ // 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;
- // if key is found delete it, otherwise ignore request
+ rpset = bt_pinlatch (bt, rparent);
+ bt_lockpage (BtLockWrite, rpset);
+
+ // find our right neighbor on right parent page
- if( !keycmp (ptr, key, len) )
- if( slotptr(bt->page, slot)->dead == 0 ) {
- slotptr(bt->page,slot)->dead = 1;
- if( slot < bt->page->cnt )
- bt->page->dirty = 1;
- bt->page->act--;
+ for( idx = 0; idx++ < rppage->cnt; )
+ if( !slotptr(rppage, idx)->dead ) {
+ bt_putid (slotptr(rppage, idx)->id, page_no);
+ break;
}
- // return if page is not empty, or it has no right sibling
+ if( idx > rppage->cnt )
+ return bt->err = BTERR_struct;
+ }
- right = bt_getid(bt->page->right);
- page_no = bt->page_no;
+ // now that there are no more pointers to our right node
+ // we can wait for delete lock on it
- if( !right || bt->page->act )
- return bt_unlockpage(bt, page_no, BtLockWrite);
+ bt_lockpage(BtLockDelete, rset);
+ bt_lockpage(BtLockWrite, rset);
- // obtain Parent lock over write lock
+ // pull contents of right page into our empty page
- if( bt_lockpage(bt, page_no, BtLockParent, NULL) )
- return bt->err;
+ memcpy (page, rpage, bt->mgr->page_size);
- // cache copy of key to delete
+ // ready to release right parent lock
+ // now that we have a new page in place
- ptr = keyptr(bt->page, bt->page->cnt);
- memcpy(leftkey, ptr, ptr->len + 1);
+ if( ppage->act == 1 ) {
+ bt_unlockpage (BtLockWrite, rpset);
+ bt_unpinlatch (rpset);
+ bt_unpinpool (rppool);
+ }
- // lock and map right page
+ // add killed right block to free chain
+ // lock latch mgr
- if( bt_lockpage(bt, right, BtLockWrite, &bt->temp) )
- return bt->err;
+ bt_spinwritelock(bt->mgr->latchmgr->lock);
- // pull contents of next page into current empty page
- memcpy (bt->page, bt->temp, bt->mgr->page_size);
+ // store free chain in allocation page second right
- // cache copy of key to update
- ptr = keyptr(bt->temp, bt->temp->cnt);
- memcpy(rightkey, ptr, ptr->len + 1);
+ bt_putid(rpage->right, bt_getid(bt->mgr->latchmgr->alloc[1].right));
+ bt_putid(bt->mgr->latchmgr->alloc[1].right, right);
- // Mark right page as deleted and point it to left page
- // until we can post updates at higher level.
+ // unlock latch mgr and right page
- bt_putid(bt->temp->right, page_no);
- bt->temp->kill = 1;
- bt->temp->cnt = 0;
+ bt_unlockpage(BtLockDelete, rset);
+ bt_unlockpage(BtLockWrite, rset);
+ bt_unpinlatch (rset);
+ bt_unpinpool (rpool);
- if( bt_unlockpage(bt, right, BtLockWrite) )
- return bt->err;
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
+ 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;
- // delete old lower key to consolidated node
+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
- if( bt_deletekey (bt, leftkey + 1, *leftkey, lvl + 1) )
+retry:
+ if( !(slot = bt_loadpage (bt, fencekey+1, *fencekey, lvl+1, BtLockWrite)) )
return bt->err;
- // redirect higher key directly to consolidated node
+ parent = bt->page_no;
+ ppage = bt->page;
+ ppool = bt->pool;
+ pset = bt->set;
- if( slot = bt_loadpage (bt, rightkey+1, *rightkey, lvl+1, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
+ // 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;
- // since key already exists, update id
+ lset = bt_pinlatch (bt, left);
+ bt_lockpage(BtLockWrite, lset);
- if( keycmp (ptr, rightkey+1, *rightkey) )
- return bt->err = BTERR_struct;
+ // 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;
+ }
- slotptr(bt->page, slot)->dead = 0;
- bt_putid(slotptr(bt->page,slot)->id, page_no);
+ // since our page will have no more pointers to it,
+ // obtain Delete lock and wait for write locks to clear
- if( bt_unlockpage(bt, bt->page_no, BtLockWrite) )
- return bt->err;
+ 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);
- // obtain write lock and
- // add right block to free chain
+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( bt_freepage (bt, right) )
+ 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
- // remove ParentModify lock
+BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len)
+{
+BtLatchSet *set;
+BtPool *pool;
+BtPage page;
+uid page_no;
+BtKey ptr;
+uint slot;
- if( bt_unlockpage(bt, page_no, BtLockParent) )
+ if( !(slot = bt_loadpage (bt, key, len, 0, BtLockWrite)) )
return bt->err;
-
- return 0;
+
+ 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
// if key exists, return row-id
// otherwise return 0
- if( ptr->len == len && !memcmp (ptr->key, key, len) )
+ if( slot <= bt->page->cnt && !keycmp (ptr, key, len) )
id = bt_getid(slotptr(bt->page,slot)->id);
else
id = 0;
- if( bt_unlockpage (bt, bt->page_no, BtLockRead) )
- return 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
-// 1 - go ahead
+// >0 new slot value
-uint bt_cleanpage(BtDb *bt, uint amt)
+uint bt_cleanpage(BtDb *bt, BtPage page, uint amt, uint slot)
{
uint nxt = bt->mgr->page_size;
-BtPage page = bt->page;
uint cnt = 0, idx = 0;
uint max = page->cnt;
+uint newslot = max;
BtKey key;
if( page->min >= (max+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
+ return slot;
// skip cleanup if nothing to reclaim
// 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 ) {
- // always leave fence key and foster children in list
- if( cnt < max - page->foster && slotptr(bt->frame,cnt)->dead )
+ 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);
// see if page has enough space now, or does it need splitting?
if( page->min >= (idx+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
+ return newslot;
return 0;
}
// add key to current page
// page must already be writelocked
-void bt_addkeytopage (BtDb *bt, uint slot, unsigned char *key, uint len, uid id, uint tod)
+void bt_addkeytopage (BtDb *bt, BtPage page, uint slot, unsigned char *key, uint len, uid id, uint tod)
{
-BtPage page = bt->page;
uint idx;
- // calculate next available slot and copy key into page
+ // find next available dead slot and copy key onto page
+ // note that foster children on the page are never dead
- page->min -= len + 1;
- ((unsigned char *)page)[page->min] = len;
- memcpy ((unsigned char *)page + page->min +1, key, len );
+ // look for next hole, but stay back from the fence key
for( idx = slot; idx < page->cnt; idx++ )
if( slotptr(page, idx)->dead )
break;
- // now insert key into array before slot
- // preserving the fence slot
-
if( idx == page->cnt )
idx++, page->cnt++;
page->act++;
+ // 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;
// 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--;
- root->foster--;
// Save left fence key.
root->act = 2;
root->lvl++;
- // release root (bt->page)
+ // release and unpin root (bt->page)
- return bt_unlockpage(bt, ROOT_page, BtLockWrite);
+ bt_unlockpage(BtLockWrite, bt->set);
+ bt_unpinlatch (bt->set);
+ bt_unpinpool (bt->pool);
+ return 0;
}
// split already locked full node
-// in current page variables
-// return unlocked.
+// return unlocked and unpinned.
-BTERR bt_splitpage (BtDb *bt)
+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];
-uid page_no = bt->page_no;
-BtPage page = bt->page;
uint tod = time(NULL);
uint lvl = page->lvl;
-uid new_page, right;
+uid new_page;
BtKey key;
- // initialize frame buffer
+ // initialize frame buffer for right node
memset (bt->frame, 0, bt->mgr->page_size);
max = page->cnt - page->foster;
- tod = (uint)time(NULL);
cnt = max / 2;
idx = 0;
// split higher half of keys to bt->frame
- // leaving foster children in the left node.
+ // 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;
- bt->frame->act++;
}
- // transfer right link node
+ // transfer right link node to new right node
- if( page_no > ROOT_page ) {
- right = bt_getid (page->right);
- bt_putid(bt->frame->right, right);
- }
+ 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 frame to it.
+ // 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 page to add
- // as foster child
+ // 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);
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;
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;
- page->act++;
}
- // insert new foster child at beginning of the current foster children
+ // 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 if any
+ // continue with old foster child keys
+ // note that none will be dead
cnt = bt->frame->cnt - bt->frame->foster;
// release wr lock on our page
- if( bt_unlockpage (bt, page_no, BtLockWrite) )
- return bt->err;
+ bt_unlockpage (BtLockWrite, set);
// obtain ParentModification lock for current page
- // to fix fence key and highest foster child on page
+ // to fix new fence key and oldest foster child on page
- if( bt_lockpage (bt, page_no, BtLockParent, NULL) )
- return bt->err;
+ bt_lockpage (BtLockParent, set);
- // get our highest foster child key to find in parent node
+ // get our new fence key to insert in parent node
- if( bt_lockpage (bt, page_no, BtLockRead, &page) )
- return bt->err;
+ bt_lockpage (BtLockRead, set);
- key = keyptr(page, page->cnt);
+ key = keyptr(page, page->cnt-1);
memcpy (fencekey, key, key->len+1);
- if( bt_unlockpage (bt, page_no, BtLockRead) )
- return bt->err;
-
- // update our parent
-try_again:
-
- do {
- slot = bt_loadpage (bt, fencekey + 1, *fencekey, lvl + 1, BtLockWrite);
-
- if( !slot )
- return bt->err;
-
- // check if parent page has enough space for any possible key
-
- if( bt_cleanpage (bt, 256) )
- break;
+ bt_unlockpage (BtLockRead, set);
- if( bt_splitpage (bt) )
+ if( bt_insertkey (bt, fencekey + 1, *fencekey, page_no, tod, lvl + 1) )
return bt->err;
- } while( 1 );
- // see if we are still a foster child from another node
+ // lock our page for writing
- if( bt_getid (slotptr(bt->page, slot)->id) != page_no ) {
- if( bt_unlockpage (bt, bt->page_no, BtLockWrite) )
- return bt->err;
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- goto try_again;
- }
+ bt_lockpage (BtLockRead, set);
- // wait until readers from parent get their locks
- // on our page
+ // switch old parent key from us to our oldest foster child
- if( bt_lockpage (bt, page_no, BtLockDelete, NULL) )
- return bt->err;
+ key = keyptr(page, page->cnt);
+ memcpy (fencekey, key, key->len+1);
- // lock our page for writing
+ new_page = bt_getid (slotptr(page, page->cnt)->id);
+ bt_unlockpage (BtLockRead, set);
- if( bt_lockpage (bt, page_no, BtLockWrite, &page) )
+ if( bt_insertkey (bt, fencekey + 1, *fencekey, new_page, tod, lvl + 1) )
return bt->err;
- // switch parent fence key to foster child
-
- if( slotptr(page, page->cnt)->dead )
- slotptr(bt->page, slot)->dead = 1;
- else
- bt_putid (slotptr(bt->page, slot)->id, bt_getid(slotptr(page, page->cnt)->id));
-
- // remove highest foster child from our page
+ // 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--;
- page->foster--;
- page->dirty = 1;
- key = keyptr(page, page->cnt);
-
- // add our new fence key for foster child to our parent
- bt_addkeytopage (bt, slot, key->key, key->len, page_no, tod);
+ bt_unlockpage (BtLockParent, set);
- if( bt_unlockpage (bt, bt->page_no, BtLockWrite) )
- return bt->err;
+ // if this emptied page,
+ // undo the foster child
- if( bt_unlockpage (bt, page_no, BtLockDelete) )
+ if( !page->act )
+ if( bt_mergeleft (bt, page, pool, set, page_no, lvl) )
return bt->err;
- if( bt_unlockpage (bt, page_no, BtLockWrite) )
- return bt->err;
+ // unlock and unpin
- return bt_unlockpage (bt, page_no, BtLockParent);
+ 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)
+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, 0, BtLockWrite) )
+ if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
ptr = keyptr(bt->page, slot);
else
{
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);
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
+ bt_unlockpage(BtLockWrite, bt->set);
+ bt_unpinlatch (bt->set);
+ bt_unpinpool (bt->pool);
+ return bt->err;
}
// check if page has enough space
- if( bt_cleanpage (bt, len) )
+ if( slot = bt_cleanpage (bt, bt->page, len, slot) )
break;
- if( bt_splitpage (bt) )
+ if( bt_splitpage (bt, bt->page, bt->pool, bt->set, bt->page_no) )
return bt->err;
}
- bt_addkeytopage (bt, slot, key, len, id, tod);
+ bt_addkeytopage (bt, bt->page, slot, key, len, id, tod);
- return bt_unlockpage (bt, bt->page_no, BtLockWrite);
+ bt_unlockpage (BtLockWrite, bt->set);
+ bt_unpinlatch (bt->set);
+ bt_unpinpool (bt->pool);
+ return 0;
}
// cache page of keys into cursor and return starting slot for given key
// cache page for retrieval
if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
memcpy (bt->cursor, bt->page, bt->mgr->page_size);
+
bt->cursor_page = bt->page_no;
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
+ bt_unlockpage(BtLockRead, bt->set);
+ bt_unpinlatch (bt->set);
+ bt_unpinpool (bt->pool);
return slot;
}
uint bt_nextkey (BtDb *bt, uint slot)
{
+BtLatchSet *set;
+BtPool *pool;
BtPage page;
uid right;
break;
bt->cursor_page = right;
-
- if( bt_lockpage(bt, right, BtLockRead, &page) )
+ if( pool = bt_pinpool (bt, right) )
+ page = bt_page (bt, pool, right);
+ else
return 0;
- memcpy (bt->cursor, page, bt->mgr->page_size);
+ set = bt_pinlatch (bt, right);
+ bt_lockpage(BtLockRead, set);
- if ( bt_unlockpage(bt, right, BtLockRead) )
- return 0;
+ memcpy (bt->cursor, page, bt->mgr->page_size);
+ bt_unlockpage(BtLockRead, set);
+ bt_unpinlatch (set);
+ bt_unpinpool (pool);
slot = 0;
} while( 1 );
#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;
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;
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") )
else if( args->num )
sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
- if( bt_insertkey (bt, key, len, line, *tod) )
+ 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( args->num )
sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
- if( bt_deletekey (bt, key, len, 0) )
+ if( bt_deletekey (bt, key, len) )
fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
len = 0;
}
fprintf(stderr, "started reading\n");
do {
- bt_lockpage (bt, page_no, BtLockRead, &page);
+ 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 (bt, page_no, BtLockRead);
+ bt_unlockpage (BtLockRead, set);
+ bt_unpinlatch (set);
+ bt_unpinpool (pool);
} while( page_no = next );
cnt--; // remove stopper key
projects / btree / blobdiff