// phase-fair reader writer lock,
// librarian page split code,
// duplicate key management
+// bi-directional cursors
// traditional buffer pool manager
-// and ACID batched key updates
+// and ACID batched key-value updates
-// 21 SEP 2014
+// 26 SEP 2014
// author: karl malbrain, malbrain@cal.berkeley.edu
uint prev; // prev entry in hash table chain
volatile ushort pin; // number of outstanding threads
ushort dirty:1; // page in cache is dirty
-#ifdef unix
- pthread_t atomictid; // pid holding atomic lock
-#else
- uint atomictid; // pid holding atomic lock
-#endif
} BtLatchSet;
// Define the length of the page record numbers
Unique,
Librarian,
Duplicate,
- Delete
+ Delete,
+ Update
} BtSlotType;
typedef struct {
unsigned char lvl:7; // level of page
unsigned char kill:1; // page is being deleted
unsigned char right[BtId]; // page number to right
+ unsigned char left[BtId]; // page number to left
+ unsigned char filler[2]; // padding to multiple of 8
} *BtPage;
// The loadpage interface object
bt->mgr->latchsets[latch->next].prev = slot;
bt->mgr->hashtable[hashidx].slot = slot;
- memset (&latch->atomictid, 0, sizeof(latch->atomictid));
latch->page_no = page_no;
latch->entry = slot;
+ latch->split = 0;
latch->prev = 0;
latch->pin = 1;
pagezero->alloc->bits = mgr->page_bits;
bt_putid(pagezero->alloc->right, MIN_lvl+1);
+ // initialize left-most LEAF page in
+ // alloc->left.
+
+ bt_putid (pagezero->alloc->left, LEAF_page);
+
if( bt_writepage (mgr, pagezero->alloc, 0) ) {
fprintf (stderr, "Unable to create btree page zero\n");
return bt_mgrclose (mgr), NULL;
// place write, read, or parent lock on requested page_no.
-void bt_lockpage(BtLock mode, BtLatchSet *set)
+void bt_lockpage(BtLock mode, BtLatchSet *latch)
{
switch( mode ) {
case BtLockRead:
- ReadLock (set->readwr);
+ ReadLock (latch->readwr);
break;
case BtLockWrite:
- WriteLock (set->readwr);
+ WriteLock (latch->readwr);
break;
case BtLockAccess:
- ReadLock (set->access);
+ ReadLock (latch->access);
break;
case BtLockDelete:
- WriteLock (set->access);
+ WriteLock (latch->access);
break;
case BtLockParent:
- WriteLock (set->parent);
+ WriteLock (latch->parent);
break;
case BtLockAtomic:
- WriteLock (set->atomic);
- break;
- case BtLockAtomic | BtLockRead:
- WriteLock (set->atomic);
- ReadLock (set->readwr);
+ WriteLock (latch->atomic);
break;
}
}
// remove write, read, or parent lock on requested page
-void bt_unlockpage(BtLock mode, BtLatchSet *set)
+void bt_unlockpage(BtLock mode, BtLatchSet *latch)
{
switch( mode ) {
case BtLockRead:
- ReadRelease (set->readwr);
+ ReadRelease (latch->readwr);
break;
case BtLockWrite:
- WriteRelease (set->readwr);
+ WriteRelease (latch->readwr);
break;
case BtLockAccess:
- ReadRelease (set->access);
+ ReadRelease (latch->access);
break;
case BtLockDelete:
- WriteRelease (set->access);
+ WriteRelease (latch->access);
break;
case BtLockParent:
- WriteRelease (set->parent);
+ WriteRelease (latch->parent);
break;
case BtLockAtomic:
- memset (&set->atomictid, 0, sizeof(set->atomictid));
- WriteRelease (set->atomic);
- break;
- case BtLockAtomic | BtLockRead:
- ReadRelease (set->readwr);
- memset (&set->atomictid, 0, sizeof(set->atomictid));
- WriteRelease (set->atomic);
+ WriteRelease (latch->atomic);
break;
}
}
// find slot in page for given key at a given level
-int bt_findslot (BtPageSet *set, unsigned char *key, uint len)
+int bt_findslot (BtPage page, unsigned char *key, uint len)
{
-uint diff, higher = set->page->cnt, low = 1, slot;
+uint diff, higher = page->cnt, low = 1, slot;
uint good = 0;
// make stopper key an infinite fence value
- if( bt_getid (set->page->right) )
+ if( bt_getid (page->right) )
higher++;
else
good++;
while( diff = higher - low ) {
slot = low + ( diff >> 1 );
- if( keycmp (keyptr(set->page, slot), key, len) < 0 )
+ if( keycmp (keyptr(page, slot), key, len) < 0 )
low = slot + 1;
else
higher = slot, good++;
set->page = bt_mappage (bt, set->latch);
- // release & unpin parent page
+ // release & unpin parent or left sibling page
if( prevpage ) {
bt_unlockpage(prevmode, prevlatch);
prevpage = 0;
}
- // skip Atomic lock on leaf page if already held
-
- if( !drill )
- if( mode & BtLockAtomic )
- if( pthread_equal (set->latch->atomictid, pthread_self()) )
- mode &= ~BtLockAtomic;
-
// obtain mode lock using lock chaining through AccessLock
bt_lockpage(mode, set->latch);
- if( mode & BtLockAtomic )
- set->latch->atomictid = pthread_self();
-
if( set->page->free )
return bt->err = BTERR_struct, 0;
if( set->page->kill )
goto slideright;
- if( slot = bt_findslot (set, key, len) ) {
+ if( slot = bt_findslot (set->page, key, len) ) {
if( drill == lvl )
return slot;
+ // find next non-dead slot -- the fence key if nothing else
+
while( slotptr(set->page, slot)->dead )
if( slot++ < set->page->cnt )
- continue;
+ continue;
else
- goto slideright;
+ return bt->err = BTERR_struct, 0;
page_no = bt_getid(valptr(set->page, slot)->value);
drill--;
bt_unlockpage (BtLockDelete, set->latch);
bt_unlockpage (BtLockWrite, set->latch);
- bt_unpinlatch (set->latch);
// unlock allocation page
root->latch->dirty = 1;
bt_freepage (bt, child);
+ bt_unpinlatch (child->latch);
} while( root->page->lvl > 1 && root->page->act == 1 );
bt_lockpage (BtLockDelete, right->latch);
bt_lockpage (BtLockWrite, right->latch);
bt_freepage (bt, right);
+ bt_unpinlatch (right->latch);
bt_unlockpage (BtLockParent, set->latch);
bt_unpinlatch (set->latch);
typedef struct {
uint entry; // latch table entry number
- uint slot:30; // page slot number
+ uint slot:31; // page slot number
uint reuse:1; // reused previous page
- uint emptied:1; // page was emptied
} AtomicMod;
typedef struct {
uid page_no; // page number for split leaf
void *next; // next key to insert
- uint entry; // latch table entry number
+ uint entry:29; // latch table entry number
+ uint type:2; // 0 == insert, 1 == delete, 2 == free
+ uint nounlock:1; // don't unlock ParentModification
unsigned char leafkey[BT_keyarray];
} AtomicKey;
+// find and load leaf page for given key
+// leave page Atomic locked and Read locked.
+
+int bt_atomicload (BtDb *bt, BtPageSet *set, unsigned char *key, uint len)
+{
+BtLatchSet *prevlatch;
+uid page_no;
+uint slot;
+
+ // find level zero page
+
+ if( !(slot = bt_loadpage (bt, set, key, len, 1, BtLockRead)) )
+ return 0;
+
+ // find next non-dead entry on this page
+ // it will be the fence key if nothing else
+
+ while( slotptr(set->page, slot)->dead )
+ if( slot++ < set->page->cnt )
+ continue;
+ else
+ return bt->err = BTERR_struct, 0;
+
+ page_no = bt_getid(valptr(set->page, slot)->value);
+ prevlatch = set->latch;
+
+ while( page_no ) {
+ if( set->latch = bt_pinlatch (bt, page_no, 1) )
+ set->page = bt_mappage (bt, set->latch);
+ else
+ return 0;
+
+ if( set->page->free || set->page->lvl )
+ return bt->err = BTERR_struct, 0;
+
+ // obtain read lock using lock chaining with Access mode
+ // release & unpin parent/left sibling page
+
+ bt_lockpage(BtLockAccess, set->latch);
+
+ bt_unlockpage(BtLockRead, prevlatch);
+ bt_unpinlatch (prevlatch);
+
+ bt_lockpage(BtLockRead, set->latch);
+ bt_unlockpage(BtLockAccess, set->latch);
+
+ // find key on page at this level
+ // and descend to requested level
+
+ if( !set->page->kill )
+ if( !bt_getid (set->page->right) || keycmp (keyptr(set->page, set->page->cnt), key, len) >= 0 ) {
+ bt_unlockpage(BtLockRead, set->latch);
+ bt_lockpage(BtLockAtomic, set->latch);
+ bt_lockpage(BtLockAccess, set->latch);
+ bt_lockpage(BtLockRead, set->latch);
+ bt_unlockpage(BtLockAccess, set->latch);
+
+ if( slot = bt_findslot (set->page, key, len) )
+ return slot;
+
+ bt_unlockpage(BtLockAtomic, set->latch);
+ }
+
+ // slide right into next page
+
+ page_no = bt_getid(set->page->right);
+ prevlatch = set->latch;
+ }
+
+ // return error on end of right chain
+
+ bt->err = BTERR_struct;
+ return 0; // return error
+}
+
// determine actual page where key is located
-// return slot number with set page locked
+// return slot number
uint bt_atomicpage (BtDb *bt, BtPage source, AtomicMod *locks, uint src, BtPageSet *set)
{
uint entry;
if( src > 1 && locks[src].reuse )
- entry = locks[src-1].entry, locks[src].entry = entry, slot = 0;
+ entry = locks[src-1].entry, slot = 0;
else
entry = locks[src].entry;
set->latch = bt->mgr->latchsets + entry;
set->page = bt_mappage (bt, set->latch);
- if( slot = bt_findslot(set, key->key, key->len) )
- return slot;
-
+ if( slot = bt_findslot(set->page, key->key, key->len) ) {
+ if( locks[src].reuse )
+ locks[src].entry = entry;
+ return slot;
+ }
} while( entry = set->latch->split );
bt->err = BTERR_atomic;
BtVal *val = valptr(source, src);
BtLatchSet *latch;
BtPageSet set[1];
-uint slot, entry;
+uint entry;
+
+ while( locks[src].slot = bt_atomicpage (bt, source, locks, src, set) ) {
+ if( locks[src].slot = bt_cleanpage(bt, set, key->len, locks[src].slot, val->len) )
+ return bt_insertslot (bt, set, locks[src].slot, key->key, key->len, val->value, val->len, slotptr(source,src)->type, 0);
- while( slot = bt_atomicpage (bt, source, locks, src, set) ) {
- if( slot = bt_cleanpage(bt, set, key->len, slot, val->len) )
- return bt_insertslot (bt, set, slot, key->key, key->len, val->value, val->len, slotptr(source,src)->type, 0);
if( entry = bt_splitpage (bt, set) )
latch = bt->mgr->latchsets + entry;
else
return bt->err;
+
+ // splice right page into split chain
+ // and WriteLock it.
+
latch->split = set->latch->split;
set->latch->split = entry;
bt_lockpage(BtLockWrite, latch);
val = valptr(set->page, slot);
set->page->garbage += ptr->len + val->len + sizeof(BtKey) + sizeof(BtVal);
- set->page->act--;
-
- // collapse empty slots beneath the fence
-
- 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;
-
set->latch->dirty = 1;
+ set->page->act--;
return 0;
}
-// qsort comparison function
-
-int bt_qsortcmp (BtSlot *slot1, BtSlot *slot2, BtPage page)
+uint bt_parentmatch (AtomicKey *head, uint entry)
{
-BtKey *key1 = (BtKey *)((unsigned char *)page + slot1->off);
-BtKey *key2 = (BtKey *)((unsigned char *)page + slot2->off);
+uint cnt = 0;
+
+ if( head )
+ do if( head->entry == entry )
+ head->nounlock = 1, cnt++;
+ while( head = head->next );
- return keycmp (key1, key2->key, key2->len);
+ return cnt;
}
// atomic modification of a batch of keys.
// causing the key constraint violation
// or zero on successful completion.
-int bt_atomicmods (BtDb *bt, BtPage source)
+int bt_atomictxn (BtDb *bt, BtPage source)
{
-uint src, idx, slot, samepage, entry, next, split;
+uint src, idx, slot, samepage, entry;
AtomicKey *head, *tail, *leaf;
BtPageSet set[1], prev[1];
unsigned char value[BtId];
BtSlot temp[1];
BtPage page;
BtVal *val;
+uid right;
int type;
locks = calloc (source->cnt + 1, sizeof(AtomicMod));
head = NULL;
tail = NULL;
- // first sort the list of keys into order to
+ // stable sort the list of keys into order to
// prevent deadlocks between threads.
- qsort_r (slotptr(source,1), source->cnt, sizeof(BtSlot), (__compar_d_fn_t)bt_qsortcmp, source);
-/*
+
for( src = 1; src++ < source->cnt; ) {
*temp = *slotptr(source,src);
key = keyptr (source,src);
break;
}
}
-*/
- // Load the leafpage for each key
+
+ // Load the leaf page for each key
+ // group same page references with reuse bit
// and determine any constraint violations
for( src = 0; src++ < source->cnt; ) {
key = keyptr(source, src);
- val = valptr(source, src);
slot = 0;
// first determine if this modification falls
// note that the far right leaf page is a special case
if( samepage = src > 1 )
- if( samepage = !bt_getid(set->page->right) || keycmp (keyptr(set->page, set->page->cnt), key->key, key->len) > 0 )
- slot = bt_findslot(set, key->key, key->len);
+ if( samepage = !bt_getid(set->page->right) || keycmp (keyptr(set->page, set->page->cnt), key->key, key->len) >= 0 )
+ slot = bt_findslot(set->page, key->key, key->len);
else // release read on previous page
bt_unlockpage(BtLockRead, set->latch);
- if( !slot ) {
- slot = bt_loadpage (bt, set, key->key, key->len, 0, BtLockAtomic | BtLockRead);
- set->latch->split = 0;
- }
-
if( !slot )
- return -1;
+ if( slot = bt_atomicload(bt, set, key->key, key->len) )
+ set->latch->split = 0;
+ else
+ return -1;
+
+ if( slotptr(set->page, slot)->type == Librarian )
+ ptr = keyptr(set->page, ++slot);
+ else
+ ptr = keyptr(set->page, slot);
if( !samepage ) {
- for(idx = 0; idx++ < source->cnt; )
- if( locks[idx].entry == set->latch->entry )
- abort();
locks[src].entry = set->latch->entry;
locks[src].slot = slot;
locks[src].reuse = 0;
locks[src].reuse = 1;
}
- if( slotptr(set->page, slot)->type == Librarian )
- ptr = keyptr(set->page, ++slot);
- else
- ptr = keyptr(set->page, slot);
-
switch( slotptr(source, src)->type ) {
case Duplicate:
case Unique:
if( !slotptr(set->page, slot)->dead )
if( slot < set->page->cnt || bt_getid (set->page->right) )
- if( ptr->len == key->len && !memcmp (ptr->key, key->key, key->len) ) {
+ if( !keycmp (ptr, key->key, key->len) ) {
// return constraint violation if key already exists
+ bt_unlockpage(BtLockRead, set->latch);
result = src;
while( src ) {
if( locks[src].entry ) {
set->latch = bt->mgr->latchsets + locks[src].entry;
bt_unlockpage(BtLockAtomic, set->latch);
- bt_unlockpage(BtLockRead, set->latch);
bt_unpinlatch (set->latch);
}
src--;
}
-
+ free (locks);
return result;
}
-
break;
-
- case Delete:
- if( !slotptr(set->page, slot)->dead )
- if( ptr->len == key->len )
- if( !memcmp (ptr->key, key->key, key->len) )
- break;
-
- // Key to delete doesn't exist
-
- result = src;
-
- while( src ) {
- if( locks[src].entry ) {
- set->latch = bt->mgr->latchsets + locks[src].entry;
- bt_unlockpage(BtLockAtomic, set->latch);
- bt_unlockpage(BtLockRead, set->latch);
- bt_unpinlatch (set->latch);
- }
- src--;
- }
-
- return result;
}
}
if( source->cnt > 1 )
bt_unlockpage(BtLockRead, set->latch);
- // obtain write lock for each page
+ // obtain write lock for each master page
for( src = 0; src++ < source->cnt; )
- if( locks[src].entry )
+ if( locks[src].reuse )
+ continue;
+ else
bt_lockpage(BtLockWrite, bt->mgr->latchsets + locks[src].entry);
// insert or delete each key
+ // process any splits or merges
+ // release Write & Atomic latches
+ // set ParentModifications and build
+ // queue of keys to insert for split pages
+ // or delete for deleted pages.
- for( src = 0; src++ < source->cnt; )
- if( slotptr(source,src)->type == Delete )
- if( bt_atomicdelete (bt, source, locks, src) )
- return -1;
- else
- continue;
- else if( bt_atomicinsert (bt, source, locks, src) )
- return -1;
- else
- continue;
+ // run through txn list backwards
- // set ParentModification and release WriteLock
- // leave empty pages locked for later processing
- // build queue of keys to insert for split pages
+ samepage = source->cnt + 1;
- for( src = 0; src++ < source->cnt; ) {
+ for( src = source->cnt; src; src-- ) {
if( locks[src].reuse )
continue;
- prev->latch = bt->mgr->latchsets + locks[src].entry;
- prev->page = bt_mappage (bt, prev->latch);
+ // perform the txn operations
+ // from smaller to larger on
+ // the same page
- // pick-up all splits from first entry
- // save page that points to this entry
+ for( idx = src; idx < samepage; idx++ )
+ switch( slotptr(source,idx)->type ) {
+ case Delete:
+ if( bt_atomicdelete (bt, source, locks, idx) )
+ return -1;
+ break;
- split = next = prev->latch->split;
+ case Duplicate:
+ case Unique:
+ if( bt_atomicinsert (bt, source, locks, idx) )
+ return -1;
+ break;
+ }
+
+ // after the same page operations have finished,
+ // process master page for splits or deletion.
- if( !prev->page->act )
- locks[src].emptied = 1;
+ latch = prev->latch = bt->mgr->latchsets + locks[src].entry;
+ prev->page = bt_mappage (bt, prev->latch);
+ samepage = src;
+
+ // pick-up all splits from master page
- while( entry = next ) {
+ entry = prev->latch->split;
+
+ while( entry ) {
set->latch = bt->mgr->latchsets + entry;
set->page = bt_mappage (bt, set->latch);
- next = set->latch->split;
+ entry = set->latch->split;
- // delete empty previous page
+ // delete empty master page
if( !prev->page->act ) {
+ memcpy (set->page->left, prev->page->left, BtId);
memcpy (prev->page, set->page, bt->mgr->page_size);
bt_lockpage (BtLockDelete, set->latch);
bt_freepage (bt, set);
+ bt_unpinlatch (set->latch);
prev->latch->dirty = 1;
-
- if( prev->page->act )
- locks[src].emptied = 0;
-
continue;
}
- // prev page is not emptied
+ // remove empty page from the split chain
- locks[src].emptied = 0;
+ if( !set->page->act ) {
+ memcpy (prev->page->right, set->page->right, BtId);
+ prev->latch->split = set->latch->split;
+ bt_lockpage (BtLockDelete, set->latch);
+ bt_freepage (bt, set);
+ bt_unpinlatch (set->latch);
+ continue;
+ }
- // schedule previous fence key update
+ // schedule prev fence key update
ptr = keyptr(prev->page,prev->page->cnt);
- leaf = malloc (sizeof(AtomicKey));
+ leaf = calloc (sizeof(AtomicKey), 1);
memcpy (leaf->leafkey, ptr, ptr->len + sizeof(BtKey));
leaf->page_no = prev->latch->page_no;
leaf->entry = prev->latch->entry;
- leaf->next = NULL;
+ leaf->type = 0;
if( tail )
tail->next = leaf;
else
head = leaf;
- latch = prev->latch;
tail = leaf;
- // remove empty block from the split chain
+ bt_putid (set->page->left, prev->latch->page_no);
+ bt_lockpage(BtLockParent, prev->latch);
+ bt_unlockpage(BtLockWrite, prev->latch);
+ *prev = *set;
+ }
- if( !set->page->act ) {
- memcpy (prev->page->right, set->page->right, BtId);
- bt_lockpage (BtLockDelete, set->latch);
- bt_freepage (bt, set);
+ // update left pointer in next right page
+ // if we did any now non-empty splits
+
+ if( latch->split ) {
+ // fix left pointer in master's original right sibling
+ // or set rightmost page in page zero
+
+ if( right = bt_getid (prev->page->right) ) {
+ if( set->latch = bt_pinlatch (bt, bt_getid(prev->page->right), 1) )
+ set->page = bt_mappage (bt, set->latch);
+ else
+ return -1;
+
+ bt_lockpage (BtLockWrite, set->latch);
+ bt_putid (set->page->left, prev->latch->page_no);
+ set->latch->dirty = 1;
+ bt_unlockpage (BtLockWrite, set->latch);
+ bt_unpinlatch (set->latch);
} else
- *prev = *set;
+ bt_putid (bt->mgr->pagezero->alloc->left, prev->latch->page_no);
- bt_lockpage(BtLockParent, latch);
- bt_unlockpage(BtLockWrite, latch);
+ // Process last page split in chain
+
+ ptr = keyptr(prev->page,prev->page->cnt);
+ leaf = calloc (sizeof(AtomicKey), 1);
+
+ memcpy (leaf->leafkey, ptr, ptr->len + sizeof(BtKey));
+ leaf->page_no = prev->latch->page_no;
+ leaf->entry = prev->latch->entry;
+ leaf->type = 0;
+
+ if( tail )
+ tail->next = leaf;
+ else
+ head = leaf;
+
+ tail = leaf;
+
+ bt_lockpage(BtLockParent, prev->latch);
+ bt_unlockpage(BtLockWrite, prev->latch);
+ bt_unlockpage(BtLockAtomic, latch);
+ continue;
}
- if( !prev->page->act )
- continue;
+ // finished if prev page occupied (either master or final split)
- if( !split ) {
- bt_unlockpage(BtLockWrite, prev->latch);
- continue;
+ if( prev->page->act ) {
+ bt_unlockpage(BtLockWrite, latch);
+ bt_unlockpage(BtLockAtomic, latch);
+ bt_unpinlatch(latch);
+ continue;
}
- // Process last page split in chain
+ // any splits were reversed, and the
+ // master page located in prev is empty, delete it
+ // by pulling over master's right sibling.
+ // Delete empty master's fence
ptr = keyptr(prev->page,prev->page->cnt);
- leaf = malloc (sizeof(AtomicKey));
+ leaf = calloc (sizeof(AtomicKey), 1);
memcpy (leaf->leafkey, ptr, ptr->len + sizeof(BtKey));
leaf->page_no = prev->latch->page_no;
leaf->entry = prev->latch->entry;
- leaf->next = NULL;
-
+ leaf->type = 1;
+
if( tail )
tail->next = leaf;
else
bt_lockpage(BtLockParent, prev->latch);
bt_unlockpage(BtLockWrite, prev->latch);
- }
+
+ // grab master's right sibling
+
+ if( set->latch = bt_pinlatch(bt, bt_getid (prev->page->right), 1) )
+ set->page = bt_mappage (bt, set->latch);
+ else
+ return -1;
+
+ bt_lockpage(BtLockWrite, set->latch);
+
+ // pull contents over empty page
+
+ memcpy (set->page->left, prev->page->left, BtId);
+ memcpy (prev->page, set->page, bt->mgr->page_size);
+
+ bt_putid (set->page->right, prev->latch->page_no);
+ set->latch->dirty = 1;
+ set->page->kill = 1;
+
+ // add new fence key for new master page contents, delete
+ // right sibling after parent posts the new master fence.
+
+ ptr = keyptr(set->page,set->page->cnt);
+ leaf = calloc (sizeof(AtomicKey), 1);
+
+ memcpy (leaf->leafkey, ptr, ptr->len + sizeof(BtKey));
+ leaf->page_no = prev->latch->page_no;
+ leaf->entry = set->latch->entry;
+ leaf->type = 2;
- // remove Atomic locks and
- // process any empty pages
+ // see if right sibling is not yet in the FIFO
- for( src = source->cnt; src; src-- ) {
- if( locks[src].reuse )
- continue;
+ if( !bt_parentmatch (head, leaf->entry) )
+ bt_lockpage(BtLockParent, set->latch);
- // delete page emptied by our atomic action
+ bt_unlockpage(BtLockWrite, set->latch);
- set->latch = bt->mgr->latchsets + locks[src].entry;
- set->page = bt_mappage (bt, set->latch);
+ if( tail )
+ tail->next = leaf;
+ else
+ head = leaf;
- if( locks[src].emptied ) {
- bt_unlockpage (BtLockAtomic, set->latch);
- if( bt_deletepage (bt, set) )
- return bt->err;
- continue;
- }
+ tail = leaf;
- bt_unlockpage (BtLockAtomic, set->latch);
+ // fix master's far right sibling's left pointer
- if( !set->latch->split )
- bt_unpinlatch (set->latch);
- }
+ if( right = bt_getid (set->page->right) ) {
+ if( set->latch = bt_pinlatch (bt, right, 1) )
+ set->page = bt_mappage (bt, set->latch);
- // add keys for any pages split during action
+ bt_lockpage (BtLockWrite, set->latch);
+ bt_putid (set->page->left, prev->latch->page_no);
+ set->latch->dirty = 1;
+
+ bt_unlockpage (BtLockWrite, set->latch);
+ bt_unpinlatch (set->latch);
+ }
+
+ bt_unlockpage(BtLockAtomic, latch);
+ }
+
+ // add & delete keys for any pages split or merged during transaction
if( leaf = head )
do {
- ptr = (BtKey *)leaf->leafkey;
+ set->latch = bt->mgr->latchsets + leaf->entry;
+ set->page = bt_mappage (bt, set->latch);
+
bt_putid (value, leaf->page_no);
+ ptr = (BtKey *)leaf->leafkey;
- if( bt_insertkey (bt, ptr->key, ptr->len, 1, value, BtId, 1) )
- return bt->err;
+ switch( leaf->type ) {
+ case 0: // insert key
+ if( bt_insertkey (bt, ptr->key, ptr->len, 1, value, BtId, 1) )
+ return -1;
+
+ break;
- bt_unlockpage (BtLockParent, bt->mgr->latchsets + leaf->entry);
- bt_unpinlatch (bt->mgr->latchsets + leaf->entry);
+ case 1: // delete key
+ if( bt_deletekey (bt, ptr->key, ptr->len, 1) )
+ return -1;
+
+ break;
+
+ case 2: // insert key & free
+ if( bt_insertkey (bt, ptr->key, ptr->len, 1, value, BtId, 1) )
+ return -1;
+
+ bt_lockpage (BtLockDelete, set->latch);
+ bt_lockpage (BtLockWrite, set->latch);
+ bt_freepage (bt, set);
+ break;
+ }
+
+ if( !leaf->nounlock )
+ bt_unlockpage (BtLockParent, set->latch);
+
+ bt_unpinlatch (set->latch);
tail = leaf->next;
free (leaf);
} while( leaf = tail );
return 0;
}
+// set cursor to highest slot on highest page
+
+uint bt_lastkey (BtDb *bt)
+{
+uid page_no = bt_getid (bt->mgr->pagezero->alloc->left);
+BtPageSet set[1];
+uint slot;
+
+ if( set->latch = bt_pinlatch (bt, page_no, 1) )
+ set->page = bt_mappage (bt, set->latch);
+ else
+ return 0;
+
+ bt_lockpage(BtLockRead, set->latch);
+
+ memcpy (bt->cursor, set->page, bt->mgr->page_size);
+ slot = set->page->cnt;
+
+ bt_unlockpage(BtLockRead, set->latch);
+ bt_unpinlatch (set->latch);
+ return slot;
+}
+
+// return previous slot on cursor page
+
+uint bt_prevkey (BtDb *bt, uint slot)
+{
+uid ourright, next, us = bt->cursor_page;
+BtPageSet set[1];
+
+ if( --slot )
+ return slot;
+
+ ourright = bt_getid(bt->cursor->right);
+
+goleft:
+ if( !(next = bt_getid(bt->cursor->left)) )
+ return 0;
+
+findourself:
+ bt->cursor_page = next;
+
+ if( set->latch = bt_pinlatch (bt, next, 1) )
+ set->page = bt_mappage (bt, set->latch);
+ else
+ return 0;
+
+ bt_lockpage(BtLockRead, set->latch);
+ memcpy (bt->cursor, set->page, bt->mgr->page_size);
+ bt_unlockpage(BtLockRead, set->latch);
+ bt_unpinlatch (set->latch);
+
+ next = bt_getid (bt->cursor->right);
+
+ if( next != us )
+ if( next == ourright )
+ goto goleft;
+ else
+ goto findourself;
+
+ return bt->cursor->cnt;
+}
+
// return next slot on cursor page
// or slide cursor right into next page
nxt -= 1;
txn[nxt] = 10;
slotptr(page,++cnt)->off = nxt;
- slotptr(page,cnt)->type = Unique;
+ slotptr(page,cnt)->type = Delete;
len = 0;
- if( cnt < 25 )
+ if( cnt < args->num )
continue;
page->cnt = cnt;
page->act = cnt;
page->min = nxt;
- if( bt_atomicmods (bt, page) )
+ if( bt_atomictxn (bt, page) )
fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
nxt = 65536;
cnt = 0;
projects / btree / blobdiff