// btree version threads2i sched_yield version
-// 30 JAN 2014
+// with reworked bt_deletekey code
+// 17 FEB 2014
// author: karl malbrain, malbrain@cal.berkeley.edu
#include <memory.h>
#include <string.h>
+#include <stddef.h>
typedef unsigned long long uid;
BtLockParent
} BtLock;
-// mode & definition for latch implementation
-
-enum {
- Mutex = 1,
- Write = 2,
- Pending = 4,
- Share = 8
-} LockMode;
+// definition for latch implementation
// exclusive is set for write access
// share is count of read accessors
// grant write lock when share == 0
-typedef struct {
- volatile ushort mutex:1;
- volatile ushort exclusive:1;
- volatile ushort pending:1;
- volatile ushort share:13;
+volatile typedef struct {
+ unsigned char mutex[1];
+ unsigned char exclusive:1;
+ unsigned char pending:1;
+ ushort share;
} BtSpinLatch;
// hash table entries
typedef struct {
BtSpinLatch readwr[1]; // read/write page lock
BtSpinLatch access[1]; // Access Intent/Page delete
- BtSpinLatch parent[1]; // adoption of foster children
+ BtSpinLatch parent[1]; // Posting of fence key in parent
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
} BtSlot;
// The key structure occupies space at the upper end of
-// each page. It's a length byte followed by the value
+// each page. It's a length byte followed by the key
// bytes.
typedef struct {
// It is immediately followed
// by the BtSlot array of keys.
-typedef struct Page {
+typedef struct BtPage_ {
uint cnt; // count of keys in page
uint act; // count of active keys
uint min; // next key offset
- unsigned char bits; // page size in bits
- unsigned char lvl:7; // level of page
+ unsigned char bits:7; // page size in bits
+ unsigned char free:1; // page is on free chain
+ unsigned char lvl:6; // level of page
+ unsigned char kill:1; // page is being deleted
unsigned char dirty:1; // page has deleted keys
unsigned char right[BtId]; // page number to right
} *BtPage;
// 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 slot; // slot index in this array
#endif
} BtPool;
+#define CLOCK_bit 0x8000 // bit in pool->pin
+
+// The loadpage interface object
+
+typedef struct {
+ uid page_no; // current page number
+ BtPage page; // current page pointer
+ BtPool *pool; // current page pool
+ BtLatchSet *latch; // current page latch set
+} BtPageSet;
+
// structure for latch manager on ALLOC_page
typedef struct {
- struct Page alloc[2]; // next & free page_nos in right ptr
+ struct BtPage_ 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
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 parent; // last loadpage was from a parent level
int found; // last delete or insert 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, uint lvl);
-extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len);
+extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uint lvl, uid id, uint tod);
+extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
extern uid bt_findkey (BtDb *bt, unsigned char *key, uint len);
extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
extern uint bt_nextkey (BtDb *bt, uint slot);
-// 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);
// 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.
+// Associated with each key is a 48 bit row-id,
+// or any other value desired.
// The b-tree root is always located at page 1.
// The first leaf page of level zero is always
// 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.
+// page cleanup. The fence key for a node is
+// always present
// Groups of pages called segments from the btree are optionally
// cached with a memory mapped pool. A hash table is used to keep
// Page 0 is dedicated to lock for new page extensions,
// and chains empty pages together for reuse.
-// The ParentModification lock on a node is obtained to prevent resplitting
-// or deleting a node before its fence is posted into its upper level.
+// The ParentModification lock on a node is obtained to serialize posting
+// or changing the fence key for a node.
// Empty pages are chained together through the ALLOC page and reused.
// Access macros to address slot and key values from the page
+// Page slots use 1 based indexing.
#define slotptr(page, slot) (((BtSlot *)(page+1)) + (slot-1))
#define keyptr(page, slot) ((BtKey)((unsigned char*)(page) + slotptr(page, slot)->off))
do {
// obtain latch mutex
#ifdef unix
- if( __sync_fetch_and_or((ushort *)latch, Mutex) & Mutex )
+ if( __sync_lock_test_and_set(latch->mutex, 1) )
continue;
#else
- if( prev = _InterlockedOr16((ushort *)latch, Mutex) & Mutex )
+ if( _InterlockedExchange8(latch->mutex, 1) )
continue;
#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
+ latch->share++;
#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
+ *latch->mutex = 0;
#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
+ _InterlockedExchange8(latch->mutex, 0);
#endif
if( prev )
return;
+
#ifdef unix
} while( sched_yield(), 1 );
#else
void bt_spinwritelock(BtSpinLatch *latch)
{
+uint prev;
+
do {
#ifdef unix
- if( __sync_fetch_and_or((ushort *)latch, Mutex | Pending) & Mutex )
+ if( __sync_lock_test_and_set(latch->mutex, 1) )
continue;
#else
- if( _InterlockedOr16((ushort *)latch, Mutex | Pending) & Mutex )
+ if( _InterlockedExchange8(latch->mutex, 1) )
continue;
#endif
- if( !(latch->share | latch->exclusive) ) {
+ if( prev = !(latch->share | latch->exclusive) )
+ latch->exclusive = 1, latch->pending = 0;
+ else
+ latch->pending = 1;
#ifdef unix
- __sync_fetch_and_or((ushort *)latch, Write);
- __sync_fetch_and_and ((ushort *)latch, ~(Mutex | Pending));
+ *latch->mutex = 0;
#else
- _InterlockedOr16((ushort *)latch, Write);
- _InterlockedAnd16((ushort *)latch, ~(Mutex | Pending));
+ _InterlockedExchange8(latch->mutex, 0);
#endif
+ if( prev )
return;
- }
-
-#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
-#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
-#endif
-
#ifdef unix
} while( sched_yield(), 1 );
#else
int bt_spinwritetry(BtSpinLatch *latch)
{
-ushort prev;
+uint prev;
#ifdef unix
- if( prev = __sync_fetch_and_or((ushort *)latch, Mutex), prev & Mutex )
+ if( __sync_lock_test_and_set(latch->mutex, 1) )
return 0;
#else
- if( prev = _InterlockedOr16((ushort *)latch, Mutex), prev & Mutex )
+ if( _InterlockedExchange8(latch->mutex, 1) )
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
+ if( prev = !(latch->exclusive | latch->share) )
+ latch->exclusive = 1;
#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Mutex);
+ *latch->mutex = 0;
#else
- _InterlockedAnd16((ushort *)latch, ~Mutex);
+ _InterlockedExchange8(latch->mutex, 0);
#endif
- return !prev;
+ return prev;
}
// clear write mode
void bt_spinreleasewrite(BtSpinLatch *latch)
{
#ifdef unix
- __sync_fetch_and_and ((ushort *)latch, ~Write);
+ while( __sync_lock_test_and_set(latch->mutex, 1) )
+ sched_yield();
#else
- _InterlockedAnd16((ushort *)latch, ~Write);
+ while( _InterlockedExchange8(latch->mutex, 1) )
+ SwitchToThread();
+#endif
+ latch->exclusive = 0;
+#ifdef unix
+ *latch->mutex = 0;
+#else
+ _InterlockedExchange8(latch->mutex, 0);
#endif
}
void bt_spinreleaseread(BtSpinLatch *latch)
{
#ifdef unix
- __sync_fetch_and_add((ushort *)latch, -Share);
+ while( __sync_lock_test_and_set(latch->mutex, 1) )
+ sched_yield();
#else
- _InterlockedExchangeAdd16 ((ushort *)latch, -Share);
+ while( _InterlockedExchange8(latch->mutex, 1) )
+ SwitchToThread();
+#endif
+ latch->share--;
+#ifdef unix
+ *latch->mutex = 0;
+#else
+ _InterlockedExchange8(latch->mutex, 0);
#endif
}
close (mgr->idx);
free (mgr->pool);
free (mgr->hash);
- free (mgr->latch);
+ free ((void *)mgr->latch);
free (mgr);
#else
FlushFileBuffers(mgr->idx);
CloseHandle(mgr->idx);
GlobalFree (mgr->pool);
GlobalFree (mgr->hash);
- GlobalFree (mgr->latch);
+ GlobalFree ((void *)mgr->latch);
GlobalFree (mgr);
#endif
}
void bt_close (BtDb *bt)
{
#ifdef unix
- if ( bt->mem )
+ if( bt->mem )
free (bt->mem);
#else
- if ( bt->mem)
+ if( bt->mem)
VirtualFree (bt->mem, 0, MEM_RELEASE);
#endif
free (bt);
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->len = 2; // create stopper key
key->key[0] = 0xff;
key->key[1] = 0xff;
latchmgr->alloc->min = mgr->page_size - 3;
pool->hashprev = pool->hashnext = NULL;
pool->basepage = page_no & ~bt->mgr->poolmask;
- pool->lru = 1;
+ pool->pin = CLOCK_bit + 1;
if( slot = bt->mgr->hash[idx] ) {
node = bt->mgr->pool + slot;
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)
BtPool *bt_pinpool(BtDb *bt, uid page_no)
{
+uint slot, hashidx, idx, victim;
BtPool *pool, *node, *next;
-uint slot, idx, victim;
// lock hash table chain
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_spinreadlock (&bt->mgr->latch[idx]);
+ hashidx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
+ bt_spinwritelock (&bt->mgr->latch[hashidx]);
// look up in hash table
- if( pool = bt_findpool(bt, page_no, idx) ) {
+ if( pool = bt_findpool(bt, page_no, hashidx) ) {
#ifdef unix
+ __sync_fetch_and_or(&pool->pin, CLOCK_bit);
__sync_fetch_and_add(&pool->pin, 1);
#else
+ _InterlockedOr16 (&pool->pin, CLOCK_bit);
_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++;
+ bt_spinreleasewrite (&bt->mgr->latch[hashidx]);
return pool;
}
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]);
+ bt_linkhash(bt, pool, page_no, hashidx);
+ bt_spinreleasewrite (&bt->mgr->latch[hashidx]);
return pool;
}
#else
victim = _InterlockedIncrement (&bt->mgr->evicted) - 1;
#endif
- victim %= bt->mgr->hashsize;
+ victim %= bt->mgr->poolmax;
+ pool = bt->mgr->pool + victim;
+ idx = (uint)(pool->basepage >> bt->mgr->seg_bits) % bt->mgr->hashsize;
+
+ if( !victim )
+ continue;
// try to get write lock
// skip entry if not obtained
- if( !bt_spinwritetry (&bt->mgr->latch[victim]) )
+ if( !bt_spinwritetry (&bt->mgr->latch[idx]) )
continue;
- // if pool entry is empty
- // or any pages are pinned
- // skip this entry
+ // skip this entry if
+ // page is pinned
+ // or clock bit is set
- if( !(pool = bt_findlru(bt, bt->mgr->hash[victim])) ) {
- bt_spinreleasewrite (&bt->mgr->latch[victim]);
+ if( pool->pin ) {
+#ifdef unix
+ __sync_fetch_and_and(&pool->pin, ~CLOCK_bit);
+#else
+ _InterlockedAnd16 (&pool->pin, ~CLOCK_bit);
+#endif
+ bt_spinreleasewrite (&bt->mgr->latch[idx]);
continue;
}
if( node = pool->hashprev )
node->hashnext = pool->hashnext;
else if( node = pool->hashnext )
- bt->mgr->hash[victim] = node->slot;
+ bt->mgr->hash[idx] = node->slot;
else
- bt->mgr->hash[victim] = 0;
+ bt->mgr->hash[idx] = 0;
if( node = pool->hashnext )
node->hashprev = pool->hashprev;
- bt_spinreleasewrite (&bt->mgr->latch[victim]);
+ bt_spinreleasewrite (&bt->mgr->latch[idx]);
// remove old file mapping
#ifdef unix
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]);
+ bt_linkhash(bt, pool, page_no, hashidx);
+ bt_spinreleasewrite (&bt->mgr->latch[hashidx]);
return pool;
}
}
uid bt_newpage(BtDb *bt, BtPage page)
{
-BtLatchSet *set;
-BtPool *pool;
+BtPageSet set[1];
uid new_page;
-BtPage pmap;
int reuse;
// lock allocation page
// 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);
+ if( set->pool = bt_pinpool (bt, new_page) )
+ set->page = bt_page (bt, set->pool, new_page);
else
return 0;
- bt_putid(bt->mgr->latchmgr->alloc[1].right, bt_getid(pmap->right));
- bt_unpinpool (pool);
+
+ bt_putid(bt->mgr->latchmgr->alloc[1].right, bt_getid(set->page->right));
+ bt_unpinpool (set->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 )
+ 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 )
+ 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 )
+ if( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->poolmask) << bt->mgr->page_bits) < bt->mgr->page_size )
return bt->err = BTERR_wrt, 0;
}
#else
// bring new page into pool and copy page.
// this will extend the file into the new pages.
- if( pool = bt_pinpool (bt, new_page) )
- pmap = bt_page (bt, pool, new_page);
+ if( set->pool = bt_pinpool (bt, new_page) )
+ set->page = bt_page (bt, set->pool, new_page);
else
return 0;
- memcpy(pmap, page, bt->mgr->page_size);
- bt_unpinpool (pool);
+ memcpy(set->page, page, bt->mgr->page_size);
+ bt_unpinpool (set->pool);
#endif
// unlock allocation latch and return new page no
// find slot in page for given key at a given level
-int bt_findslot (BtDb *bt, unsigned char *key, uint len)
+int bt_findslot (BtPageSet *set, unsigned char *key, uint len)
{
-uint diff, higher = bt->page->cnt, low = 1, slot;
+uint diff, higher = set->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) )
+ if( bt_getid (set->page->right) )
higher++;
else
good++;
- // low is the next candidate.
+ // low is the lowest candidate.
// loop ends when they meet
- // if good, higher is already
- // tested as .ge. the given key.
+ // higher is already
+ // tested as .ge. the passed key.
while( diff = higher - low ) {
slot = low + ( diff >> 1 );
- if( keycmp (keyptr(bt->page, slot), key, len) < 0 )
+ if( keycmp (keyptr(set->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;
+ 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)
+int bt_loadpage (BtDb *bt, BtPageSet *set, unsigned char *key, uint len, uint lvl, BtLock lock)
{
uid page_no = ROOT_page, prevpage = 0;
-BtLatchSet *set, *prevset;
uint drill = 0xff, slot;
+BtLatchSet *prevlatch;
uint mode, prevmode;
BtPool *prevpool;
-int parent = 1;
// start at root of btree and drill down
- bt->set = NULL;
-
do {
// determine lock mode of drill level
- mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead;
+ mode = (drill == lvl) ? lock : BtLockRead;
- bt->set = bt_pinlatch (bt, page_no);
- bt->page_no = page_no;
+ set->latch = bt_pinlatch (bt, page_no);
+ set->page_no = page_no;
// pin page contents
- if( bt->pool = bt_pinpool (bt, page_no) )
- bt->page = bt_page (bt, bt->pool, page_no);
+ if( set->pool = bt_pinpool (bt, page_no) )
+ set->page = bt_page (bt, set->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);
+ bt_lockpage(BtLockAccess, set->latch);
// release & unpin parent page
if( prevpage ) {
- bt_unlockpage(prevmode, prevset);
- bt_unpinlatch (prevset);
+ bt_unlockpage(prevmode, prevlatch);
+ bt_unpinlatch (prevlatch);
bt_unpinpool (prevpool);
prevpage = 0;
}
// obtain read lock using lock chaining
- bt_lockpage(mode, bt->set);
+ bt_lockpage(mode, set->latch);
+
+ if( set->page->free )
+ return bt->err = BTERR_struct, 0;
if( page_no > ROOT_page )
- bt_unlockpage(BtLockAccess, bt->set);
+ bt_unlockpage(BtLockAccess, set->latch);
// re-read and re-lock root after determining actual level of root
- if( bt->page->lvl != drill) {
- if ( bt->page_no != ROOT_page )
+ if( set->page->lvl != drill) {
+ if( set->page_no != ROOT_page )
return bt->err = BTERR_struct, 0;
- drill = bt->page->lvl;
+ drill = set->page->lvl;
- if( lock == BtLockWrite && drill == lvl ) {
- bt_unlockpage(mode, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
+ if( lock != BtLockRead && drill == lvl ) {
+ bt_unlockpage(mode, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
continue;
}
}
+ prevpage = set->page_no;
+ prevlatch = set->latch;
+ prevpool = set->pool;
+ prevmode = mode;
+
// find key on page at this level
// and descend to requested level
- if( slot = bt_findslot (bt, key, len) ) {
+ if( !set->page->kill )
+ if( slot = bt_findslot (set, key, len) ) {
if( drill == lvl )
- return bt->parent = parent, slot;
+ return slot;
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
+ while( slotptr(set->page, slot)->dead )
+ if( slot++ < set->page->cnt )
continue;
- else {
- page_no = bt_getid(bt->page->right);
- parent = 0;
+ else
goto slideright;
- }
- page_no = bt_getid(slotptr(bt->page, slot)->id);
- parent = 1;
+ page_no = bt_getid(slotptr(set->page, slot)->id);
drill--;
- }
+ continue;
+ }
// or slide right into next page
- else {
- page_no = bt_getid(bt->page->right);
- parent = 0;
- }
-
- // continue down / right using overlapping locks
- // to protect pages being split.
-
slideright:
- prevpage = bt->page_no;
- prevpool = bt->pool;
- prevset = bt->set;
- prevmode = mode;
+ page_no = bt_getid(set->page->right);
+
} while( page_no );
// return error on end of right chain
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.
+// return page to free list
+// page must be delete & write locked
-BTERR bt_mergeright (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl, uint slot)
+void bt_freepage (BtDb *bt, BtPageSet *set)
{
-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
- // 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;
- }
+ // lock allocation page
- // now that there are no more pointers to our right node
- // we can wait for delete lock on it
+ bt_spinwritelock (bt->mgr->latchmgr->lock);
- bt_lockpage(BtLockDelete, rset);
- bt_lockpage(BtLockWrite, rset);
+ // store chain in second right
+ bt_putid(set->page->right, bt_getid(bt->mgr->latchmgr->alloc[1].right));
+ bt_putid(bt->mgr->latchmgr->alloc[1].right, set->page_no);
+ set->page->free = 1;
- // pull contents of right page into our empty page
+ // unlock released page
- memcpy (page, rpage, bt->mgr->page_size);
+ bt_unlockpage (BtLockDelete, set->latch);
+ bt_unlockpage (BtLockWrite, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
- // ready to release right parent lock
- // now that we have a new page in place
+ // unlock allocation page
- if( ppage->act == 1 ) {
- bt_unlockpage (BtLockWrite, rpset);
- bt_unpinlatch (rpset);
- bt_unpinpool (rppool);
- }
+ bt_spinreleasewrite (bt->mgr->latchmgr->lock);
+}
- // add killed right block to free chain
- // lock latch mgr
+// a fence key was deleted from a page
+// push new fence value upwards
- bt_spinwritelock(bt->mgr->latchmgr->lock);
+BTERR bt_fixfence (BtDb *bt, BtPageSet *set, uint lvl)
+{
+unsigned char leftkey[256], rightkey[256];
+uid page_no;
+BtKey ptr;
- // store free chain in allocation page second right
+ // remove the old fence value
- bt_putid(rpage->right, bt_getid(bt->mgr->latchmgr->alloc[1].right));
- bt_putid(bt->mgr->latchmgr->alloc[1].right, right);
+ ptr = keyptr(set->page, set->page->cnt);
+ memcpy (rightkey, ptr, ptr->len + 1);
- // unlock latch mgr and right page
+ memset (slotptr(set->page, set->page->cnt--), 0, sizeof(BtSlot));
+ set->page->dirty = 1;
- bt_unlockpage(BtLockDelete, rset);
- bt_unlockpage(BtLockWrite, rset);
- bt_unpinlatch (rset);
- bt_unpinpool (rpool);
+ ptr = keyptr(set->page, set->page->cnt);
+ memcpy (leftkey, ptr, ptr->len + 1);
+ page_no = set->page_no;
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
+ bt_lockpage (BtLockParent, set->latch);
+ bt_unlockpage (BtLockWrite, set->latch);
- // delete our obsolete fence key from our parent
+ // insert new (now smaller) fence key
- slotptr(ppage, slot)->dead = 1;
- ppage->dirty = 1;
+ if( bt_insertkey (bt, leftkey+1, *leftkey, lvl+1, page_no, time(NULL)) )
+ return bt->err;
- // if our parent now empty
- // remove it from the tree
+ // now delete old fence key
- if( ppage->act-- == 1 )
- if( bt_mergeleft (bt, ppage, ppool, pset, parent, lvl+1) )
+ if( bt_deletekey (bt, rightkey+1, *rightkey, lvl+1) )
return bt->err;
-rmergexit:
- bt_unlockpage (BtLockWrite, pset);
- bt_unpinlatch (pset);
- bt_unpinpool (ppool);
-
- bt->found = 1;
- return bt->err = 0;
+ bt_unlockpage (BtLockParent, set->latch);
+ bt_unpinlatch(set->latch);
+ bt_unpinpool (set->pool);
+ return 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.
+// root has a single child
+// collapse a level from the tree
-BTERR bt_mergeleft (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no, uint lvl)
+BTERR bt_collapseroot (BtDb *bt, BtPageSet *root)
{
-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 posted in our parent
-
- if( !bt->parent ) {
- bt_unlockpage (BtLockWrite, pset);
- bt_unpinlatch (pset);
- bt_unpinpool (ppool);
-#ifdef unix
- sched_yield();
-#else
- SwitchToThread();
-#endif
- goto retry;
- }
+BtPageSet child[1];
+uint idx;
- // find our left neighbor in our parent page
+ // find the child entry and promote as new root contents
- for( idx = slot; --idx; )
- if( !slotptr(ppage, idx)->dead )
+ do {
+ for( idx = 0; idx++ < root->page->cnt; )
+ if( !slotptr(root->page, 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
+ child->page_no = bt_getid (slotptr(root->page, idx)->id);
- left = bt_getid (slotptr(ppage, idx)->id);
+ child->latch = bt_pinlatch (bt, child->page_no);
+ bt_lockpage (BtLockDelete, child->latch);
+ bt_lockpage (BtLockWrite, child->latch);
- if( lpool = bt_pinpool (bt, left) )
- lpage = bt_page (bt, lpool, left);
+ if( child->pool = bt_pinpool (bt, child->page_no) )
+ child->page = bt_page (bt, child->pool, child->page_no);
else
return bt->err;
- lset = bt_pinlatch (bt, left);
- bt_lockpage(BtLockWrite, lset);
+ memcpy (root->page, child->page, bt->mgr->page_size);
+ bt_freepage (bt, child);
- // wait until 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;
- }
+ } while( root->page->lvl > 1 && root->page->act == 1 );
- // 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);
+ bt_unlockpage (BtLockWrite, root->latch);
+ bt_unpinlatch (root->latch);
+ bt_unpinpool (root->pool);
+ return 0;
+}
- // if we aren't dead yet,
- // get ready for exit
+// find and delete key on page by marking delete flag bit
+// if page becomes empty, delete it from the btree
- if( page->act ) {
- bt_unlockpage(BtLockDelete, set);
- bt_unlockpage(BtLockWrite, lset);
- bt_unpinlatch (lset);
- bt_unpinpool (lpool);
- goto lmergexit;
- }
+BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl)
+{
+unsigned char lowerfence[256], higherfence[256];
+uint slot, idx, dirty = 0, fence, found;
+BtPageSet set[1], right[1];
+BtKey ptr;
- // are we are the fence key for our parent?
- // if so, grab our old fence key
+ if( slot = bt_loadpage (bt, set, key, len, lvl, BtLockWrite) )
+ ptr = keyptr(set->page, slot);
+ else
+ return bt->err;
- if( postfence = slot == ppage->cnt ) {
- ptr = keyptr (ppage, ppage->cnt);
- memcpy(fencekey, ptr, ptr->len + 1);
- memset(slotptr(ppage, ppage->cnt), 0, sizeof(BtSlot));
+ // are we deleting a fence slot?
- // clear out other dead slots
+ fence = slot == set->page->cnt;
- while( --ppage->cnt )
- if( slotptr(ppage, ppage->cnt)->dead )
- memset(slotptr(ppage, ppage->cnt), 0, sizeof(BtSlot));
- else
- break;
+ // if key is found delete it, otherwise ignore request
- ptr = keyptr (ppage, ppage->cnt);
- memcpy(postkey, ptr, ptr->len + 1);
- } else
- slotptr(ppage,slot)->dead = 1;
+ if( found = !keycmp (ptr, key, len) )
+ if( found = slotptr(set->page, slot)->dead == 0 ) {
+ dirty = slotptr(set->page, slot)->dead = 1;
+ set->page->dirty = 1;
+ set->page->act--;
- ppage->dirty = 1;
- ppage->act--;
+ // collapse empty slots
- // push our right neighbor pointer to our left
+ while( idx = set->page->cnt - 1 )
+ if( slotptr(set->page, idx)->dead ) {
+ *slotptr(set->page, idx) = *slotptr(set->page, idx + 1);
+ memset (slotptr(set->page, set->page->cnt--), 0, sizeof(BtSlot));
+ } else
+ break;
+ }
- memcpy (lpage->right, page->right, BtId);
+ // did we delete a fence key in an upper level?
- // add ourselves to free chain
- // lock latch mgr
+ if( dirty && lvl && set->page->act && fence )
+ if( bt_fixfence (bt, set, lvl) )
+ return bt->err;
+ else
+ return bt->found = found, 0;
- bt_spinwritelock(bt->mgr->latchmgr->lock);
+ // is this a collapsed root?
- // 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);
+ if( lvl > 1 && set->page_no == ROOT_page && set->page->act == 1 )
+ if( bt_collapseroot (bt, set) )
+ return bt->err;
+ else
+ return bt->found = found, 0;
- // unlock latch mgr and pages
+ // return if page is not empty
- bt_spinreleasewrite(bt->mgr->latchmgr->lock);
- bt_unlockpage(BtLockWrite, lset);
- bt_unpinlatch (lset);
- bt_unpinpool (lpool);
+ if( set->page->act ) {
+ bt_unlockpage(BtLockWrite, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+ return bt->found = found, 0;
+ }
- // release our node's delete lock
+ // cache copy of fence key
+ // to post in parent
- bt_unlockpage(BtLockDelete, set);
+ ptr = keyptr(set->page, set->page->cnt);
+ memcpy (lowerfence, ptr, ptr->len + 1);
-lmergexit:
- bt_unlockpage (BtLockWrite, pset);
- bt_unpinpool (ppool);
+ // obtain lock on right page
- // do we need to post parent's fence key in its parent?
+ right->page_no = bt_getid(set->page->right);
+ right->latch = bt_pinlatch (bt, right->page_no);
+ bt_lockpage (BtLockWrite, right->latch);
- if( !postfence || parent == ROOT_page ) {
- bt_unpinlatch (pset);
- bt->found = 1;
- return bt->err = 0;
- }
+ // pin page contents
- // interlock parent fence post
+ if( right->pool = bt_pinpool (bt, right->page_no) )
+ right->page = bt_page (bt, right->pool, right->page_no);
+ else
+ return 0;
- bt_lockpage (BtLockParent, pset);
+ if( right->page->kill )
+ return bt->err = BTERR_struct;
- // load parent's parent page
-posttry:
- if( !(slot = bt_loadpage (bt, fencekey+1, *fencekey, lvl+2, BtLockWrite)) )
- return bt->err;
+ // pull contents of right peer into our empty page
- 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;
+ memcpy (set->page, right->page, bt->mgr->page_size);
- page = bt->page;
+ // cache copy of key to update
- 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;
+ ptr = keyptr(right->page, right->page->cnt);
+ memcpy (higherfence, ptr, ptr->len + 1);
- bt_unlockpage (BtLockParent, pset);
- bt_unpinlatch (pset);
+ // mark right page deleted and point it to left page
+ // until we can post parent updates
- bt_unlockpage (BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
+ bt_putid (right->page->right, set->page_no);
+ right->page->kill = 1;
- bt->found = 1;
- return bt->err = 0;
-}
+ bt_lockpage (BtLockParent, right->latch);
+ bt_unlockpage (BtLockWrite, right->latch);
-// find and delete key on page by marking delete flag bit
-// if page becomes empty, delete it from the btree
+ bt_lockpage (BtLockParent, set->latch);
+ bt_unlockpage (BtLockWrite, set->latch);
-BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len)
-{
-BtLatchSet *set;
-BtPool *pool;
-BtPage page;
-uid page_no;
-BtKey ptr;
-uint slot;
+ // redirect higher key directly to our new node contents
- if( !(slot = bt_loadpage (bt, key, len, 0, BtLockWrite)) )
- return bt->err;
+ if( bt_insertkey (bt, higherfence+1, *higherfence, lvl+1, set->page_no, time(NULL)) )
+ return bt->err;
- page_no = bt->page_no;
- page = bt->page;
- pool = bt->pool;
- set = bt->set;
+ // delete old lower key to our node
- // if key is found delete it, otherwise ignore request
+ if( bt_deletekey (bt, lowerfence+1, *lowerfence, lvl+1) )
+ return bt->err;
- ptr = keyptr(page, slot);
+ // obtain delete and write locks to right node
- 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 (BtLockParent, right->latch);
+ bt_lockpage (BtLockDelete, right->latch);
+ bt_lockpage (BtLockWrite, right->latch);
+ bt_freepage (bt, right);
- bt_unlockpage(BtLockWrite, set);
- bt_unpinlatch (set);
- bt_unpinpool (pool);
- return bt->err = 0;
+ bt_unlockpage (BtLockParent, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+ bt->found = found;
+ return 0;
}
// find key in leaf level and return row-id
uid bt_findkey (BtDb *bt, unsigned char *key, uint len)
{
+BtPageSet set[1];
uint slot;
+uid id = 0;
BtKey ptr;
-uid id;
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- ptr = keyptr(bt->page, slot);
+ if( slot = bt_loadpage (bt, set, key, len, 0, BtLockRead) )
+ ptr = keyptr(set->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;
+ if( slot <= set->page->cnt )
+ if( !keycmp (ptr, key, len) )
+ id = bt_getid(slotptr(set->page,slot)->id);
- bt_unlockpage (BtLockRead, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
+ bt_unlockpage (BtLockRead, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
return id;
}
page->act = 0;
// try cleaning up page first
-
- // always leave fence key in the array
- // otherwise, remove deleted key
+ // by removing deleted keys
while( cnt++ < max ) {
if( cnt == slot )
if( cnt < max && slotptr(bt->frame,cnt)->dead )
continue;
- // copy key
+ // copy the key across
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++;
return 0;
}
-// add key to current page
-// page must already be writelocked
+// split the root and raise the height of the btree
-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
-
- 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;
-}
-
-BTERR bt_splitroot(BtDb *bt, unsigned char *leftkey, uid page_no2)
+BTERR bt_splitroot(BtDb *bt, BtPageSet *root, unsigned char *leftkey, uid page_no2)
{
uint nxt = bt->mgr->page_size;
-BtPage root = bt->page;
-uid new_page;
+uid left;
// Obtain an empty page to use, and copy the current
- // root contents into it
+ // root contents into it, e.g. lower keys
- if( !(new_page = bt_newpage(bt, root)) )
+ if( !(left = bt_newpage(bt, root->page)) )
return bt->err;
// preserve the page info at the bottom
- // and set rest to zero
+ // of higher keys and set rest to zero
- memset(root+1, 0, bt->mgr->page_size - sizeof(*root));
+ memset(root->page+1, 0, bt->mgr->page_size - sizeof(*root->page));
- // insert first key on newroot page
+ // insert lower keys page fence key on newroot page as first key
nxt -= *leftkey + 1;
- memcpy ((unsigned char *)root + nxt, leftkey, *leftkey + 1);
- bt_putid(slotptr(root, 1)->id, new_page);
- slotptr(root, 1)->off = nxt;
+ memcpy ((unsigned char *)root->page + nxt, leftkey, *leftkey + 1);
+ bt_putid(slotptr(root->page, 1)->id, left);
+ slotptr(root->page, 1)->off = nxt;
- // insert second key (stopper key) on newroot page
+ // insert stopper key on newroot page
// and increase the root height
nxt -= 3;
- *((unsigned char *)root + nxt) = 2;
- memset ((unsigned char *)root + nxt + 1, 0xff, 2);
- bt_putid(slotptr(root, 2)->id, page_no2);
- 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);
+ ((unsigned char *)root->page)[nxt] = 2;
+ ((unsigned char *)root->page)[nxt+1] = 0xff;
+ ((unsigned char *)root->page)[nxt+2] = 0xff;
+ bt_putid(slotptr(root->page, 2)->id, page_no2);
+ slotptr(root->page, 2)->off = nxt;
+
+ bt_putid(root->page->right, 0);
+ root->page->min = nxt; // reset lowest used offset and key count
+ root->page->cnt = 2;
+ root->page->act = 2;
+ root->page->lvl++;
+
+ // release and unpin root
+
+ bt_unlockpage(BtLockWrite, root->latch);
+ bt_unpinlatch (root->latch);
+ bt_unpinpool (root->pool);
return 0;
}
// split already locked full node
-// return unlocked and unpinned.
+// return unlocked.
-BTERR bt_splitpage (BtDb *bt, BtPage page, BtPool *pool, BtLatchSet *set, uid page_no)
+BTERR bt_splitpage (BtDb *bt, BtPageSet *set)
{
-uint slot, cnt, idx, max, nxt = bt->mgr->page_size;
-unsigned char rightkey[256], leftkey[256];
-uint tod = time(NULL);
-uint lvl = page->lvl;
-uid new_page;
+uint cnt = 0, idx = 0, max, nxt = bt->mgr->page_size;
+unsigned char fencekey[256], rightkey[256];
+uint lvl = set->page->lvl;
+BtPageSet right[1];
+uint prev;
BtKey key;
- // initialize frame buffer for right node
+ // split higher half of keys to bt->frame
memset (bt->frame, 0, bt->mgr->page_size);
- max = page->cnt;
+ max = set->page->cnt;
cnt = max / 2;
idx = 0;
- // split higher half of keys to bt->frame
-
while( cnt++ < max ) {
- key = keyptr(page, cnt);
+ key = keyptr(set->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) )
+
+ memcpy(slotptr(bt->frame,++idx)->id, slotptr(set->page,cnt)->id, BtId);
+ if( !(slotptr(bt->frame, idx)->dead = slotptr(set->page, cnt)->dead) )
bt->frame->act++;
- slotptr(bt->frame, idx)->tod = slotptr(page, cnt)->tod;
+ slotptr(bt->frame, idx)->tod = slotptr(set->page, cnt)->tod;
slotptr(bt->frame, idx)->off = nxt;
}
- // transfer right link node to new right node
+ // remember existing fence key for new page to the right
- if( page_no > ROOT_page )
- memcpy (bt->frame->right, page->right, BtId);
+ memcpy (rightkey, key, key->len + 1);
bt->frame->bits = bt->mgr->page_bits;
bt->frame->min = nxt;
bt->frame->cnt = idx;
bt->frame->lvl = lvl;
- // get new free page and write right frame to it.
+ // link right node
- if( !(new_page = bt_newpage(bt, bt->frame)) )
- return bt->err;
+ if( set->page_no > ROOT_page )
+ memcpy (bt->frame->right, set->page->right, BtId);
- // remember fence key for new right page to add
- // as right sibling to the left node
+ // get new free page and write higher keys to it.
- key = keyptr(bt->frame, idx);
- memcpy (rightkey, key, key->len + 1);
+ if( !(right->page_no = bt_newpage(bt, bt->frame)) )
+ return bt->err;
// update lower keys to continue in old page
- memcpy (bt->frame, page, bt->mgr->page_size);
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
+ memcpy (bt->frame, set->page, bt->mgr->page_size);
+ memset (set->page+1, 0, bt->mgr->page_size - sizeof(*set->page));
nxt = bt->mgr->page_size;
- page->dirty = 0;
- page->act = 0;
+ set->page->dirty = 0;
+ set->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;
+ memcpy ((unsigned char *)set->page + nxt, key, key->len + 1);
+ memcpy(slotptr(set->page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
+ slotptr(set->page, idx)->tod = slotptr(bt->frame, cnt)->tod;
+ slotptr(set->page, idx)->off = nxt;
+ set->page->act++;
}
- // finalize left page and save fence key
-
- memcpy(leftkey, key, key->len + 1);
- page->min = nxt;
- page->cnt = idx;
+ // remember fence key for smaller page
- // link new right page
+ memcpy(fencekey, key, key->len + 1);
- bt_putid (page->right, new_page);
+ bt_putid(set->page->right, right->page_no);
+ set->page->min = nxt;
+ set->page->cnt = idx;
// if current page is the root page, split it
- if( page_no == ROOT_page )
- return bt_splitroot (bt, leftkey, new_page);
+ if( set->page_no == ROOT_page )
+ return bt_splitroot (bt, set, fencekey, right->page_no);
- // obtain ParentModification lock for current page
+ // insert new fences in their parent pages
- bt_lockpage (BtLockParent, set);
+ right->latch = bt_pinlatch (bt, right->page_no);
+ bt_lockpage (BtLockParent, right->latch);
- // release wr lock on our page.
- // this will keep out another SMO
+ bt_lockpage (BtLockParent, set->latch);
+ bt_unlockpage (BtLockWrite, set->latch);
- bt_unlockpage (BtLockWrite, set);
+ // insert new fence for reformulated left block of smaller keys
- // insert key for old page (lower keys)
-
- if( bt_insertkey (bt, leftkey + 1, *leftkey, page_no, tod, lvl + 1) )
+ if( bt_insertkey (bt, fencekey+1, *fencekey, lvl+1, set->page_no, time(NULL)) )
return bt->err;
- // switch old parent key from us to our right page
+ // switch fence for right block of larger keys to new right page
- if( bt_insertkey (bt, rightkey + 1, *rightkey, new_page, tod, lvl + 1) )
+ if( bt_insertkey (bt, rightkey+1, *rightkey, lvl+1, right->page_no, time(NULL)) )
return bt->err;
- // unlock and unpin
+ bt_unlockpage (BtLockParent, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
- bt_unlockpage (BtLockParent, set);
- bt_unpinlatch (set);
- bt_unpinpool (pool);
+ bt_unlockpage (BtLockParent, right->latch);
+ bt_unpinlatch (right->latch);
return 0;
}
-
// Insert new key into the btree at given level.
-BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uid id, uint tod, uint lvl)
+BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uint lvl, uid id, uint tod)
{
+BtPageSet set[1];
uint slot, idx;
-BtPage page;
BtKey ptr;
while( 1 ) {
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
+ if( slot = bt_loadpage (bt, set, key, len, lvl, BtLockWrite) )
+ ptr = keyptr(set->page, slot);
else
{
- if ( !bt->err )
+ 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;
+ if( slotptr(set->page, slot)->dead )
+ set->page->act++;
+ slotptr(set->page, slot)->dead = 0;
+ slotptr(set->page, slot)->tod = tod;
+ bt_putid(slotptr(set->page,slot)->id, id);
+ bt_unlockpage(BtLockWrite, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+ return 0;
}
// check if page has enough space
- if( slot = bt_cleanpage (bt, bt->page, len, slot) )
+ if( slot = bt_cleanpage (bt, set->page, len, slot) )
break;
- if( bt_splitpage (bt, bt->page, bt->pool, bt->set, bt->page_no) )
+ if( bt_splitpage (bt, set) )
return bt->err;
}
- bt_addkeytopage (bt, bt->page, slot, key, len, id, tod);
+ // calculate next available slot and copy key into page
+
+ set->page->min -= len + 1; // reset lowest used offset
+ ((unsigned char *)set->page)[set->page->min] = len;
+ memcpy ((unsigned char *)set->page + set->page->min +1, key, len );
+
+ for( idx = slot; idx < set->page->cnt; idx++ )
+ if( slotptr(set->page, idx)->dead )
+ break;
+
+ // now insert key into array before slot
- bt_unlockpage (BtLockWrite, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
+ if( idx == set->page->cnt )
+ idx++, set->page->cnt++;
+
+ set->page->act++;
+
+ while( idx > slot )
+ *slotptr(set->page, idx) = *slotptr(set->page, idx -1), idx--;
+
+ bt_putid(slotptr(set->page,slot)->id, id);
+ slotptr(set->page, slot)->off = set->page->min;
+ slotptr(set->page, slot)->tod = tod;
+ slotptr(set->page, slot)->dead = 0;
+
+ bt_unlockpage (BtLockWrite, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
return 0;
}
uint bt_startkey (BtDb *bt, unsigned char *key, uint len)
{
+BtPageSet set[1];
uint slot;
// cache page for retrieval
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- memcpy (bt->cursor, bt->page, bt->mgr->page_size);
- bt->cursor_page = bt->page_no;
+ if( slot = bt_loadpage (bt, set, key, len, 0, BtLockRead) )
+ memcpy (bt->cursor, set->page, bt->mgr->page_size);
+ else
+ return 0;
+
+ bt->cursor_page = set->page_no;
- bt_unlockpage(BtLockRead, bt->set);
- bt_unpinlatch (bt->set);
- bt_unpinpool (bt->pool);
+ bt_unlockpage(BtLockRead, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
return slot;
}
uint bt_nextkey (BtDb *bt, uint slot)
{
-BtLatchSet *set;
-BtPool *pool;
-BtPage page;
+BtPageSet set[1];
uid right;
do {
right = bt_getid(bt->cursor->right);
+
while( slot++ < bt->cursor->cnt )
if( slotptr(bt->cursor,slot)->dead )
continue;
- else if( right || (slot < bt->cursor->cnt) )
+ else if( right || (slot < bt->cursor->cnt) ) // skip infinite stopper
return slot;
else
break;
break;
bt->cursor_page = right;
- if( pool = bt_pinpool (bt, right) )
- page = bt_page (bt, pool, right);
+
+ if( set->pool = bt_pinpool (bt, right) )
+ set->page = bt_page (bt, set->pool, right);
else
return 0;
- set = bt_pinlatch (bt, right);
- bt_lockpage(BtLockRead, set);
+ set->latch = bt_pinlatch (bt, right);
+ bt_lockpage(BtLockRead, set->latch);
- memcpy (bt->cursor, page, bt->mgr->page_size);
+ memcpy (bt->cursor, set->page, bt->mgr->page_size);
- bt_unlockpage(BtLockRead, set);
- bt_unpinlatch (set);
- bt_unpinpool (pool);
+ bt_unlockpage(BtLockRead, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
slot = 0;
+
} while( 1 );
return bt->err = 0;
return slotptr(bt->cursor,slot)->tod;
}
-
#ifdef STANDALONE
+#ifndef unix
+double getCpuTime(int type)
+{
+FILETIME crtime[1];
+FILETIME xittime[1];
+FILETIME systime[1];
+FILETIME usrtime[1];
+SYSTEMTIME timeconv[1];
+double ans = 0;
+
+ memset (timeconv, 0, sizeof(SYSTEMTIME));
+
+ switch( type ) {
+ case 0:
+ GetSystemTimeAsFileTime (xittime);
+ FileTimeToSystemTime (xittime, timeconv);
+ ans = (double)timeconv->wDayOfWeek * 3600 * 24;
+ break;
+ case 1:
+ GetProcessTimes (GetCurrentProcess(), crtime, xittime, systime, usrtime);
+ FileTimeToSystemTime (usrtime, timeconv);
+ break;
+ case 2:
+ GetProcessTimes (GetCurrentProcess(), crtime, xittime, systime, usrtime);
+ FileTimeToSystemTime (systime, timeconv);
+ break;
+ }
+
+ ans += (double)timeconv->wHour * 3600;
+ ans += (double)timeconv->wMinute * 60;
+ ans += (double)timeconv->wSecond;
+ ans += (double)timeconv->wMilliseconds / 1000;
+ return ans;
+}
+#else
+#include <time.h>
+#include <sys/resource.h>
+
+double getCpuTime(int type)
+{
+struct rusage used[1];
+struct timeval tv[1];
+
+ switch( type ) {
+ case 0:
+ gettimeofday(tv, NULL);
+ return (double)tv->tv_sec + (double)tv->tv_usec / 1000000;
+
+ case 1:
+ getrusage(RUSAGE_SELF, used);
+ return (double)used->ru_utime.tv_sec + (double)used->ru_utime.tv_usec / 1000000;
+
+ case 2:
+ getrusage(RUSAGE_SELF, used);
+ return (double)used->ru_stime.tv_sec + (double)used->ru_stime.tv_usec / 1000000;
+ }
+
+ return 0;
+}
+#endif
+
void bt_latchaudit (BtDb *bt)
{
ushort idx, hashidx;
-BtLatchSet *set;
-BtPool *pool;
-BtPage page;
-uid page_no;
+uid next, page_no;
+BtLatchSet *latch;
+BtKey ptr;
#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;
+ if( *(uint *)(bt->mgr->latchmgr->lock) )
+ fprintf(stderr, "Alloc page locked\n");
+ *(uint *)(bt->mgr->latchmgr->lock) = 0;
+
+ for( idx = 1; idx <= bt->mgr->latchmgr->latchdeployed; idx++ ) {
+ latch = bt->mgr->latchsets + idx;
+ if( *(uint *)latch->readwr )
+ fprintf(stderr, "latchset %d rwlocked for page %.8x\n", idx, latch->page_no);
+ *(uint *)latch->readwr = 0;
+
+ if( *(uint *)latch->access )
+ fprintf(stderr, "latchset %d accesslocked for page %.8x\n", idx, latch->page_no);
+ *(uint *)latch->access = 0;
+
+ if( *(uint *)latch->parent )
+ fprintf(stderr, "latchset %d parentlocked for page %.8x\n", idx, latch->page_no);
+ *(uint *)latch->parent = 0;
+
+ if( latch->pin ) {
+ fprintf(stderr, "latchset %d pinned for page %.8x\n", idx, latch->page_no);
+ latch->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( *(uint *)(bt->mgr->latchmgr->table[hashidx].latch) )
+ fprintf(stderr, "hash entry %d locked\n", hashidx);
+
+ *(uint *)(bt->mgr->latchmgr->table[hashidx].latch) = 0;
+
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 )
+ latch = bt->mgr->latchsets + idx;
+ if( *(uint *)latch->busy )
+ fprintf(stderr, "latchset %d busylocked for page %.8x\n", idx, latch->page_no);
+ *(uint *)latch->busy = 0;
+ if( latch->hash != hashidx )
fprintf(stderr, "latchset %d wrong hashidx\n", idx);
- if( set->pin )
- fprintf(stderr, "latchset %d pinned\n", idx);
- } while( idx = set->next );
+ if( latch->pin )
+ fprintf(stderr, "latchset %d pinned for page %.8x\n", idx, latch->page_no);
+ } while( idx = latch->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);
+
+ next = bt->mgr->latchmgr->nlatchpage + LATCH_page;
+ page_no = LEAF_page;
+
+ while( page_no < bt_getid(bt->mgr->latchmgr->alloc->right) ) {
+ pread (bt->mgr->idx, bt->frame, bt->mgr->page_size, page_no << bt->mgr->page_bits);
+ if( !bt->frame->free )
+ for( idx = 0; idx++ < bt->frame->cnt - 1; ) {
+ ptr = keyptr(bt->frame, idx+1);
+ if( keycmp (keyptr(bt->frame, idx), ptr->key, ptr->len) >= 0 )
+ fprintf(stderr, "page %.8x idx %.2x out of order\n", page_no, idx);
+ }
+
+ if( page_no > LEAF_page )
+ next = page_no + 1;
+ page_no = next;
}
#endif
}
unsigned char key[256];
ThreadArg *args = arg;
int ch, len = 0, slot;
-BtLatchSet *set;
+BtPageSet set[1];
time_t tod[1];
-BtPool *pool;
-BtPage page;
BtKey ptr;
BtDb *bt;
FILE *in;
else if( args->num )
sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
- if( bt_insertkey (bt, key, len, line, *tod, 0) )
+ if( bt_insertkey (bt, key, len, 0, line, *tod) )
fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
len = 0;
}
else if( args->num )
sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
- if( bt_deletekey (bt, key, len) )
+ if( bt_deletekey (bt, key, len, 0) )
fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
len = 0;
}
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);
- }
+ fprintf(stderr, "started scanning\n");
+ do {
+ if( set->pool = bt_pinpool (bt, page_no) )
+ set->page = bt_page (bt, set->pool, page_no);
+ else
+ break;
+ set->latch = bt_pinlatch (bt, page_no);
+ bt_lockpage (BtLockRead, set->latch);
+ next = bt_getid (set->page->right);
+ cnt += set->page->act;
+
+ for( slot = 0; slot++ < set->page->cnt; )
+ if( next || slot < set->page->cnt )
+ if( !slotptr(set->page, slot)->dead ) {
+ ptr = keyptr(set->page, slot);
+ fwrite (ptr->key, ptr->len, 1, stdout);
+ fputc ('\n', stdout);
+ }
+
+ bt_unlockpage (BtLockRead, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+ } while( page_no = next );
+ cnt--; // remove stopper key
+ fprintf(stderr, " Total keys read %d\n", cnt);
break;
case 'c':
- fprintf(stderr, "started reading\n");
+ fprintf(stderr, "started counting\n");
+ next = bt->mgr->latchmgr->nlatchpage + LATCH_page;
+ page_no = LEAF_page;
- 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 );
+ while( page_no < bt_getid(bt->mgr->latchmgr->alloc->right) ) {
+ uid off = page_no << bt->mgr->page_bits;
+#ifdef unix
+ pread (bt->mgr->idx, bt->frame, bt->mgr->page_size, off);
+#else
+ DWORD amt[1];
+
+ SetFilePointer (bt->mgr->idx, (long)off, (long*)(&off)+1, FILE_BEGIN);
+ if( !ReadFile(bt->mgr->idx, bt->frame, bt->mgr->page_size, amt, NULL))
+ return bt->err = BTERR_map;
+
+ if( *amt < bt->mgr->page_size )
+ return bt->err = BTERR_map;
+#endif
+ if( !bt->frame->free && !bt->frame->lvl )
+ cnt += bt->frame->act;
+ if( page_no > LEAF_page )
+ next = page_no + 1;
+ page_no = next;
+ }
+
cnt--; // remove stopper key
fprintf(stderr, " Total keys read %d\n", cnt);
break;
{
int idx, cnt, len, slot, err;
int segsize, bits = 16;
+double start, stop;
#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;
+float elapsed;
int num = 0;
char key[1];
BtMgr *mgr;
exit(0);
}
-#ifdef unix
- gettimeofday(&start, NULL);
-#else
- time(start);
-#endif
+ start = getCpuTime(0);
if( argc > 3 )
bits = atoi(argv[3]);
#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);
+ elapsed = getCpuTime(0) - start;
+ fprintf(stderr, " real %dm%.3fs\n", (int)(elapsed/60), elapsed - (int)(elapsed/60)*60);
+ elapsed = getCpuTime(1);
+ fprintf(stderr, " user %dm%.3fs\n", (int)(elapsed/60), elapsed - (int)(elapsed/60)*60);
+ elapsed = getCpuTime(2);
+ fprintf(stderr, " sys %dm%.3fs\n", (int)(elapsed/60), elapsed - (int)(elapsed/60)*60);
+
bt_mgrclose (mgr);
}
projects / btree / blobdiff