From: unknown Date: Fri, 14 Feb 2014 19:06:25 +0000 (-0800) Subject: fix original problem with bt_deletekey, obviating need for btree2t.c X-Git-Url: https://pd.if.org/git/?p=btree;a=commitdiff_plain;h=07891352e2c84646ffe3071b4ebf708a97cf5c3e fix original problem with bt_deletekey, obviating need for btree2t.c --- diff --git a/btree2s.c b/btree2s.c index e2f1ae1..af39f90 100644 --- a/btree2s.c +++ b/btree2s.c @@ -1,5 +1,5 @@ // btree version 2s -// 02 FEB 2014 +// 13 FEB 2014 // author: karl malbrain, malbrain@cal.berkeley.edu @@ -121,8 +121,10 @@ typedef struct { uint min; // next key offset unsigned char bits:7; // page size in bits unsigned char free:1; // page is on free list - unsigned char lvl:7; // level of page + unsigned char lvl:5; // level of page + unsigned char kill:1; // page is being deleted unsigned char dirty:1; // page is dirty + unsigned char posted:1; // page is posted in parent unsigned char right[BtId]; // page number to right } *BtPage; @@ -168,7 +170,6 @@ typedef struct _BtDb { int hashmask; // number of pages in segments - 1 int hashsize; // size of hash table int found; // last deletekey found key - int fence; // last load page used fence position BtHash *lrufirst; // lru list head BtHash *lrulast; // lru list tail ushort *cache; // hash table for cached segments @@ -893,16 +894,6 @@ int amt[1]; BTERR bt_freepage(BtDb *bt, uid page_no) { - // obtain delete lock on deleted node - - if( bt_lockpage(bt, page_no, BtLockDelete) ) - return bt->err; - - // obtain write lock on deleted node - - if( bt_lockpage(bt, page_no, BtLockWrite) ) - return bt->err; - if( bt_mappage (bt, &bt->temp, page_no) ) return bt->err; @@ -1110,7 +1101,8 @@ uint mode, prevmode; // find key on page at this level // and descend to requested level - if( slot = bt_findslot (bt, key, len) ) { + if( !bt->page->kill ) + if( slot = bt_findslot (bt, key, len) ) { if( drill == lvl ) return slot; @@ -1125,11 +1117,10 @@ uint mode, prevmode; if( slot <= bt->page->cnt ) { page_no = bt_getid(slotptr(bt->page, slot)->id); - bt->fence = slot == bt->page->cnt; drill--; continue; } - } + } // or slide right into next page @@ -1143,47 +1134,150 @@ uint mode, prevmode; return 0; // return error } +// a fence key was deleted from a page +// push new fence value up to the root + +BTERR bt_fixfence (BtDb *bt, uid page_no, uint lvl) +{ +unsigned char leftkey[256], rightkey[256]; +BtKey ptr; +uid left; + + // remove deleted key, the old fence value + + ptr = keyptr(bt->page, bt->page->cnt--); + memcpy(rightkey, ptr, ptr->len + 1); + + left = bt_getid (slotptr(bt->page, bt->page->cnt)->id); + ptr = keyptr(bt->page, bt->page->cnt); + memcpy(leftkey, ptr, ptr->len + 1); + + if( bt_update (bt, bt->page, page_no) ) + return bt->err; + + if( bt_unlockpage (bt, page_no, BtLockWrite) ) + return bt->err; + + if( bt_lockpage (bt, left, BtLockParent) ) + return bt->err; + + // insert new (now smaller) fence key + + if( bt_insertkey (bt, leftkey+1, *leftkey, lvl + 1, page_no, time(NULL)) ) + return bt->err; + + if( bt_unlockpage (bt, left, BtLockParent) ) + return bt->err; + + // remove old (larger) fence key + + return bt_deletekey (bt, rightkey+1, *rightkey, lvl + 1); +} + +// root has a single child +// collapse a level from the btree +// call with root locked in bt->page + +BTERR bt_collapseroot (BtDb *bt, BtPage root) +{ +uid child; +uint idx; + + // find the child entry + // and promote to new root + + do { + for( idx = 0; idx++ < root->cnt; ) + if( !slotptr(root, idx)->dead ) + break; + + child = bt_getid (slotptr(root, idx)->id); + + if( bt_lockpage (bt, child, BtLockDelete) ) + return bt->err; + + if( bt_lockpage (bt, child, BtLockWrite) ) + return bt->err; + + if( bt_mappage (bt, &bt->temp, child) ) + return bt->err; + + memcpy (root, bt->temp, bt->page_size); + + if( bt_update (bt, root, ROOT_page) ) + return bt->err; + + if( bt_freepage (bt, child) ) + return bt->err; + + } while( root->lvl > 1 && root->act == 1 ); + + return bt_unlockpage (bt, ROOT_page, BtLockWrite); +} + // find and delete key on page by marking delete flag bit // when page becomes empty, delete it BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl) { unsigned char lowerkey[256], higherkey[256]; -uint slot, tod, dirty = 0; +uint slot, dirty = 0, idx, fence; uid page_no, right; BtKey ptr; +retry: if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) ) ptr = keyptr(bt->page, slot); else return bt->err; + // are we deleting a fence slot? + + fence = slot == bt->page->cnt; + // if key is found delete it, otherwise ignore request if( !keycmp (ptr, key, len) ) - if( slotptr(bt->page, slot)->dead == 0 ) { - dirty = slotptr(bt->page,slot)->dead = 1; - if( slot < bt->page->cnt ) - bt->page->dirty = 1; - bt->page->act--; - } - - // return if page is not empty, or - // if non-leaf level or fence key + if( slotptr(bt->page, slot)->dead == 0 ) { + dirty = slotptr(bt->page,slot)->dead = 1; + if( slot < bt->page->cnt ) + bt->page->dirty = 1; + bt->page->act--; + + // collapse empty slots + + while( idx = bt->page->cnt - 1 ) + if( slotptr(bt->page, idx)->dead ) { + *slotptr(bt->page, idx) = *slotptr(bt->page, idx + 1); + memset (slotptr(bt->page, bt->page->cnt--), 0, sizeof(BtSlot)); + } else + break; + } right = bt_getid(bt->page->right); page_no = bt->page_no; - if( lvl || bt->page->act || bt->fence ) + // did we delete our fence key in an upper level? + + if( dirty && lvl && bt->page->act && fence ) + return bt_fixfence (bt, page_no, lvl); + + // is this a collapsed root? + + if( lvl > 1 && page_no == ROOT_page && bt->page->act == 1 ) + return bt_collapseroot (bt, bt->page); + + // return if page is not empty + + if( bt->page->act ) if ( dirty && bt_update(bt, bt->page, page_no) ) return bt->err; else return bt_unlockpage(bt, page_no, BtLockWrite); - // obtain Parent lock over write lock + // mark page being deleted - if( bt_lockpage(bt, page_no, BtLockParent) ) - return bt->err; + bt->page->kill = 1; // cache copy of fence key // in order to find parent @@ -1191,6 +1285,17 @@ BtKey ptr; ptr = keyptr(bt->page, bt->page->cnt); memcpy(lowerkey, ptr, ptr->len + 1); + if( bt_update(bt, bt->page, page_no) ) + return bt->err; + + if( bt_unlockpage(bt, page_no, BtLockWrite) ) + return bt->err; + + // obtain Parent lock + + if( bt_lockpage(bt, page_no, BtLockParent) ) + return bt->err; + // lock and map right page if ( bt_lockpage(bt, right, BtLockWrite) ) @@ -1199,6 +1304,28 @@ BtKey ptr; if( bt_mappage (bt, &bt->temp, right) ) return bt->err; + // is our right sibling being deleted? + + if( bt->temp->kill ) { + if ( bt_unlockpage(bt, right, BtLockWrite) ) + return bt->err; + + if( bt_unlockpage(bt, page_no, BtLockParent) ) + return bt->err; +#ifdef linux + sched_yield (); +#else + SwitchToThread(); +#endif + goto retry; + } + + if( bt_lockpage(bt, page_no, BtLockWrite) ) + return bt->err; + + if( bt_mappage (bt, &bt->page, page_no) ) + return bt->err; + // pull contents of next page into current empty page memcpy (bt->page, bt->temp, bt->page_size); @@ -1212,7 +1339,7 @@ BtKey ptr; // until we can post updates at higher level. bt_putid(bt->temp->right, page_no); - bt->temp->cnt = 0; + bt->temp->kill = 1; if( bt_update(bt, bt->page, page_no) ) return bt->err; @@ -1226,30 +1353,33 @@ BtKey ptr; if( bt_unlockpage(bt, page_no, BtLockWrite) ) return bt->err; + // redirect higher key directly to consolidated node + + if( bt_insertkey (bt, higherkey+1, *higherkey, lvl + 1, page_no, time(NULL)) ) + return bt->err; + // delete old lower key to consolidated node if( bt_deletekey (bt, lowerkey + 1, *lowerkey, lvl + 1) ) return bt->err; - // redirect higher key directly to consolidated node - - tod = (uint)time(NULL); + // obtain delete lock on deleted node + // add right block to free chain - if( bt_insertkey (bt, higherkey+1, *higherkey, lvl + 1, page_no, tod) ) + if( bt_lockpage(bt, right, BtLockDelete) ) return bt->err; - // obtain write lock and - // add right block to free chain + // obtain write lock on deleted node + + if( bt_lockpage(bt, right, BtLockWrite) ) + return bt->err; if( bt_freepage (bt, right) ) return bt->err; // remove ParentModify lock - if( bt_unlockpage(bt, page_no, BtLockParent) ) - return bt->err; - - return 0; + return bt_unlockpage(bt, page_no, BtLockParent); } // find key in leaf level and return row-id @@ -1340,16 +1470,16 @@ int ret; // split the root and raise the height of the btree -BTERR bt_splitroot(BtDb *bt, unsigned char *newkey, unsigned char *oldkey, uid page_no2) +BTERR bt_splitroot(BtDb *bt, unsigned char *leftkey, uid page_no2) { uint nxt = bt->page_size; BtPage root = bt->page; -uid new_page; +uid right; // Obtain an empty page to use, and copy the current // root contents into it - if( !(new_page = bt_newpage(bt, root)) ) + if( !(right = bt_newpage(bt, root)) ) return bt->err; // preserve the page info at the bottom @@ -1359,16 +1489,18 @@ uid new_page; // insert first key on newroot page - nxt -= *newkey + 1; - memcpy ((unsigned char *)root + nxt, newkey, *newkey + 1); - bt_putid(slotptr(root, 1)->id, new_page); + nxt -= *leftkey + 1; + memcpy ((unsigned char *)root + nxt, leftkey, *leftkey + 1); + bt_putid(slotptr(root, 1)->id, right); slotptr(root, 1)->off = nxt; // insert second key on newroot page // and increase the root height - nxt -= *oldkey + 1; - memcpy ((unsigned char *)root + nxt, oldkey, *oldkey + 1); + nxt -= 3; + ((unsigned char *)root)[nxt] = 2; + ((unsigned char *)root)[nxt+1] = 0xff; + ((unsigned char *)root)[nxt+2] = 0xff; bt_putid(slotptr(root, 2)->id, page_no2); slotptr(root, 2)->off = nxt; @@ -1392,19 +1524,15 @@ uid new_page; BTERR bt_splitpage (BtDb *bt) { uint cnt = 0, idx = 0, max, nxt = bt->page_size; -unsigned char oldkey[256], lowerkey[256]; uid page_no = bt->page_no, right; +unsigned char fencekey[256]; BtPage page = bt->page; uint lvl = page->lvl; -uid new_page; BtKey key; -uint tod; // split higher half of keys to bt->frame // the last key (fence key) might be dead - tod = (uint)time(NULL); - memset (bt->frame, 0, bt->page_size); max = (int)page->cnt; cnt = max / 2; @@ -1421,10 +1549,6 @@ uint tod; slotptr(bt->frame, idx)->off = nxt; } - // remember existing fence key for new page to the right - - memcpy (oldkey, key, key->len + 1); - bt->frame->bits = bt->page_bits; bt->frame->min = nxt; bt->frame->cnt = idx; @@ -1432,14 +1556,12 @@ uint tod; // link 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); // get new free page and write frame to it. - if( !(new_page = bt_newpage(bt, bt->frame)) ) + if( !(right = bt_newpage(bt, bt->frame)) ) return bt->err; // update lower keys to continue in old page @@ -1447,6 +1569,8 @@ uint tod; memcpy (bt->frame, page, bt->page_size); memset (page+1, 0, bt->page_size - sizeof(*page)); nxt = bt->page_size; + page->posted = 0; + page->dirty = 0; page->act = 0; cnt = 0; idx = 0; @@ -1466,52 +1590,62 @@ uint tod; // remember fence key for old page - memcpy(lowerkey, key, key->len + 1); - bt_putid(page->right, new_page); + memcpy (fencekey, key, key->len + 1); + bt_putid(page->right, right); page->min = nxt; page->cnt = idx; // if current page is the root page, split it if( page_no == ROOT_page ) - return bt_splitroot (bt, lowerkey, oldkey, new_page); + return bt_splitroot (bt, fencekey, right); // update left (containing) node if( bt_update(bt, page, page_no) ) return bt->err; - // obtain Parent/Write locks - // for left and right node pages - - if( bt_lockpage (bt, new_page, BtLockParent) ) + if( bt_unlockpage (bt, page_no, BtLockWrite) ) return bt->err; - if( bt_lockpage (bt, page_no, BtLockParent) ) + // insert new fences in parent pages + + do { + if( bt_lockpage (bt, page_no, BtLockParent) ) return bt->err; - // release wr lock on left page + if( bt_lockpage (bt, page_no, BtLockWrite) ) + return bt->err; - if( bt_unlockpage (bt, page_no, BtLockWrite) ) + if( bt_mappage (bt, &bt->page, page_no) ) return bt->err; - // insert new fence for reformulated left block + key = keyptr(bt->page, bt->page->cnt); + memcpy (fencekey, key, key->len + 1); - if( bt_insertkey (bt, lowerkey+1, *lowerkey, lvl + 1, page_no, tod) ) - return bt->err; + if( bt->page->posted ) { + if( bt_unlockpage (bt, page_no, BtLockParent) ) + return bt->err; + return bt_unlockpage (bt, page_no, BtLockWrite); + } + + right = bt_getid (bt->page->right); + bt->page->posted = 1; - // fix old fence for newly allocated right block page + if( bt_update (bt, bt->page, page_no) ) + return bt->err; - if( bt_insertkey (bt, oldkey+1, *oldkey, lvl + 1, new_page, tod) ) + if( bt_unlockpage (bt, page_no, BtLockWrite) ) return bt->err; - // release Parent & Write locks + // insert new fence for reformulated left block - if( bt_unlockpage (bt, new_page, BtLockParent) ) + if( bt_insertkey (bt, fencekey+1, *fencekey, lvl + 1, page_no, time(NULL)) ) return bt->err; - if( bt_unlockpage (bt, page_no, BtLockParent) ) + if( bt_unlockpage (bt, page_no, BtLockParent) ) return bt->err; + } while( page_no = right ); return 0; } diff --git a/btree2t.c b/btree2t.c deleted file mode 100644 index 900cc1f..0000000 --- a/btree2t.c +++ /dev/null @@ -1,2332 +0,0 @@ -// btree version 2t -// 15 FEB 2014 - -// author: karl malbrain, malbrain@cal.berkeley.edu - -/* -This work, including the source code, documentation -and related data, is placed into the public domain. - -The orginal author is Karl Malbrain. - -THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY -OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF -MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE, -ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE -RESULTING FROM THE USE, MODIFICATION, OR -REDISTRIBUTION OF THIS SOFTWARE. -*/ - -// Please see the project home page for documentation -// code.google.com/p/high-concurrency-btree - -#define _FILE_OFFSET_BITS 64 -#define _LARGEFILE64_SOURCE - -#ifdef linux -#define _GNU_SOURCE -#endif - -#ifdef unix -#include -#include -#include -#include -#include -#include -#include -#include -#else -#define WIN32_LEAN_AND_MEAN -#include -#include -#include -#include -#include -#endif - -#include -#include -#include - -typedef unsigned long long uid; - -#ifndef unix -typedef unsigned long long off64_t; -typedef unsigned short ushort; -typedef unsigned int uint; -#endif - -#define BT_ro 0x6f72 // ro -#define BT_rw 0x7772 // rw -#define BT_fl 0x6c66 // fl - -#define BT_maxbits 24 // maximum page size in bits -#define BT_minbits 9 // minimum page size in bits -#define BT_minpage (1 << BT_minbits) // minimum page size - -/* -There are five lock types for each node in three independent sets: -1. (set 1) AccessIntent: Sharable. Going to Read the node. Incompatible with NodeDelete. -2. (set 1) NodeDelete: Exclusive. About to release the node. Incompatible with AccessIntent. -3. (set 2) ReadLock: Sharable. Read the node. Incompatible with WriteLock. -4. (set 2) WriteLock: Exclusive. Modify the node. Incompatible with ReadLock and other WriteLocks. -5. (set 3) ParentModification: Exclusive. Change the node's parent keys. Incompatible with another ParentModification. -*/ - -typedef enum{ - BtLockAccess, - BtLockDelete, - BtLockRead, - BtLockWrite, - BtLockParent -}BtLock; - -// Define the length of the page and key pointers - -#define BtId 6 - -// Page key slot definition. - -// If BT_maxbits is 15 or less, you can save 2 bytes -// for each key stored by making the first two uints -// into ushorts. You can also save 4 bytes by removing -// the tod field from the key. - -// Keys are marked dead, but remain on the page until -// cleanup is called. - -typedef struct { - uint off:BT_maxbits; // page offset for key start - uint dead:1; // set for deleted key - uint tod; // time-stamp for key - unsigned char id[BtId]; // id associated with key -} BtSlot; - -// The key structure occupies space at the upper end of -// each page. It's a length byte followed by the value -// bytes. - -typedef struct { - unsigned char len; - unsigned char key[0]; -} *BtKey; - -// The first part of an index page. -// It is immediately followed -// by the BtSlot array of keys. - -typedef struct BtPage_ { - uint cnt; // count of keys in page - uint act; // count of active keys - uint min; // next key offset - unsigned char bits:7; // page size in bits - unsigned char free:1; // page is on free list - unsigned char lvl:4; // level of page - unsigned char kill:1; // page is empty - unsigned char dirty:1; // page is dirty - unsigned char posted:1; // page fence is posted - unsigned char goright:1; // continue to right link - unsigned char right[BtId]; // page number to right - unsigned char fence[256]; // page fence key -} *BtPage; - -// The loadpage interface object - -typedef struct { - uid page_no; - BtPage page; -} BtPageSet; - -// The memory mapping hash table entry - -typedef struct { - BtPage page; // mapped page pointer - uid page_no; // mapped page number - void *lruprev; // least recently used previous cache block - void *lrunext; // lru next cache block - void *hashprev; // previous cache block for the same hash idx - void *hashnext; // next cache block for the same hash idx -#ifndef unix - HANDLE hmap; -#endif -} BtHash; - -// The object structure for Btree access - -typedef struct _BtDb { - uint page_size; // each page size - uint page_bits; // each page size in bits - uint seg_bits; // segment size in pages in bits - uid page_no; // current page number - uid cursor_page; // current cursor page number - int err; - uint mode; // read-write mode - uint mapped_io; // use memory mapping - BtPage temp; // temporary frame buffer (memory mapped/file IO) - BtPage temp2; // temporary frame buffer (memory mapped/file IO) - BtPage parent; // current page's parent node (memory mapped/file IO) - BtPage alloc; // frame for alloc page (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; // zeroes frame buffer (never mapped) - BtPage page; // temporary page (memory mapped/file IO) -#ifdef unix - int idx; -#else - HANDLE idx; -#endif - unsigned char *mem; // frame, cursor, page memory buffer - int nodecnt; // highest page cache segment in use - int nodemax; // highest page cache segment allocated - int hashmask; // number of pages in segments - 1 - int hashsize; // size of hash table - int posted; // last loadpage found posted key - int found; // last insert/delete found key - BtHash *lrufirst; // lru list head - BtHash *lrulast; // lru list tail - ushort *cache; // hash table for cached segments - BtHash nodes[1]; // segment cache follows -} BtDb; - -typedef enum { -BTERR_ok = 0, -BTERR_struct, -BTERR_ovflw, -BTERR_lock, -BTERR_map, -BTERR_wrt, -BTERR_hash -} BTERR; - -// B-Tree functions -extern void bt_close (BtDb *bt); -extern BtDb *bt_open (char *name, uint mode, uint bits, uint cacheblk, uint pgblk); -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); -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_removepage (BtDb *bt, uid page_no, uint lvl, unsigned char *pagefence); - -// Helper functions to return slot values - -extern BtKey bt_key (BtDb *bt, uint slot); -extern uid bt_uid (BtDb *bt, uint slot); -extern uint bt_tod (BtDb *bt, uint slot); - -// BTree page number constants -#define ALLOC_page 0 -#define ROOT_page 1 -#define LEAF_page 2 - -// Number of levels to create in a new BTree - -#define MIN_lvl 2 - -// The page is allocated from low and hi ends. -// The key offsets and row-id's are allocated -// from the bottom, while the text of the key -// is allocated from the top. When the two -// areas meet, the page is split into two. - -// A key consists of a length byte, two bytes of -// index number (0 - 65534), and up to 253 bytes -// of key value. Duplicate keys are discarded. -// Associated with each key is a 48 bit row-id. - -// The b-tree root is always located at page 1. -// The first leaf page of level zero is always -// located on page 2. - -// The b-tree pages are linked with right -// pointers to facilitate enumerators, -// and provide for concurrency. - -// When to root page fills, it is split in two and -// the tree height is raised by a new root at page -// one with two keys. - -// Deleted keys are marked with a dead bit until -// page cleanup - -// Groups of pages from the btree are optionally -// cached with memory mapping. A hash table is used to keep -// track of the cached pages. This behaviour is controlled -// by the number of cache blocks parameter and pages per block -// given to bt_open. - -// To achieve maximum concurrency one page is locked at a time -// as the tree is traversed to find leaf key in question. The right -// page numbers are used in cases where the page is being split, -// or consolidated. - -// Page 0 is dedicated to lock for new page extensions, -// and chains empty pages together for reuse. - -// Parent locks are obtained to prevent resplitting or deleting a node -// before its fence is posted into its upper level. - -// Empty nodes are chained together through the ALLOC page and reused. - -// A special open mode of BT_fl is provided to safely access files on -// WIN32 networks. WIN32 network operations should not use memory mapping. -// This WIN32 mode sets FILE_FLAG_NOBUFFERING and FILE_FLAG_WRITETHROUGH -// to prevent local caching of network file contents. - -// 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)) - -void bt_putid(unsigned char *dest, uid id) -{ -int i = BtId; - - while( i-- ) - dest[i] = (unsigned char)id, id >>= 8; -} - -uid bt_getid(unsigned char *src) -{ -uid id = 0; -int i; - - for( i = 0; i < BtId; i++ ) - id <<= 8, id |= *src++; - - return id; -} - -// place write, read, or parent lock on requested page_no. - -BTERR bt_lockpage(BtDb *bt, uid page_no, BtLock mode) -{ -off64_t off = page_no << bt->page_bits; -#ifdef unix -int flag = PROT_READ | ( bt->mode == BT_ro ? 0 : PROT_WRITE ); -struct flock lock[1]; -#else -uint flags = 0, len; -OVERLAPPED ovl[1]; -#endif - - if( mode == BtLockRead || mode == BtLockWrite ) - off += 1 * sizeof(*bt->page); // use second segment - - if( mode == BtLockParent ) - off += 2 * sizeof(*bt->page); // use third segment - -#ifdef unix - memset (lock, 0, sizeof(lock)); - - lock->l_start = off; - lock->l_type = (mode == BtLockDelete || mode == BtLockWrite || mode == BtLockParent) ? F_WRLCK : F_RDLCK; - lock->l_len = sizeof(*bt->page); - lock->l_whence = 0; - - if( fcntl (bt->idx, F_SETLKW, lock) < 0 ) - return bt->err = BTERR_lock; - - return 0; -#else - memset (ovl, 0, sizeof(ovl)); - ovl->OffsetHigh = (uint)(off >> 32); - ovl->Offset = (uint)off; - len = sizeof(*bt->page); - - // use large offsets to - // simulate advisory locking - - ovl->OffsetHigh |= 0x80000000; - - if( mode == BtLockDelete || mode == BtLockWrite || mode == BtLockParent ) - flags |= LOCKFILE_EXCLUSIVE_LOCK; - - if( LockFileEx (bt->idx, flags, 0, len, 0L, ovl) ) - return bt->err = 0; - - return bt->err = BTERR_lock; -#endif -} - -// remove write, read, or parent lock on requested page_no. - -BTERR bt_unlockpage(BtDb *bt, uid page_no, BtLock mode) -{ -off64_t off = page_no << bt->page_bits; -#ifdef unix -struct flock lock[1]; -#else -OVERLAPPED ovl[1]; -uint len; -#endif - - if( mode == BtLockRead || mode == BtLockWrite ) - off += 1 * sizeof(*bt->page); // use second segment - - if( mode == BtLockParent ) - off += 2 * sizeof(*bt->page); // use third segment - -#ifdef unix - memset (lock, 0, sizeof(lock)); - - lock->l_start = off; - lock->l_type = F_UNLCK; - lock->l_len = sizeof(*bt->page); - lock->l_whence = 0; - - if( fcntl (bt->idx, F_SETLK, lock) < 0 ) - return bt->err = BTERR_lock; -#else - memset (ovl, 0, sizeof(ovl)); - ovl->OffsetHigh = (uint)(off >> 32); - ovl->Offset = (uint)off; - len = sizeof(*bt->page); - - // use large offsets to - // simulate advisory locking - - ovl->OffsetHigh |= 0x80000000; - - if( !UnlockFileEx (bt->idx, 0, len, 0, ovl) ) - return GetLastError(), bt->err = BTERR_lock; -#endif - - return bt->err = 0; -} - -// close and release memory - -void bt_close (BtDb *bt) -{ -BtHash *hash; -#ifdef unix - // release mapped pages - - if( hash = bt->lrufirst ) - do munmap (hash->page, (bt->hashmask+1) << bt->page_bits); - while(hash = hash->lrunext); - - if ( bt->mem ) - free (bt->mem); - close (bt->idx); - free (bt->cache); - free (bt); -#else - if( hash = bt->lrufirst ) - do - { - FlushViewOfFile(hash->page, 0); - UnmapViewOfFile(hash->page); - CloseHandle(hash->hmap); - } while(hash = hash->lrunext); - - if ( bt->mem) - VirtualFree (bt->mem, 0, MEM_RELEASE); - FlushFileBuffers(bt->idx); - CloseHandle(bt->idx); - GlobalFree (bt->cache); - GlobalFree (bt); -#endif -} - -// open/create new btree -// call with file_name, BT_openmode, bits in page size (e.g. 16), -// size of mapped page cache (e.g. 8192) or zero for no mapping. - -BtDb *bt_open (char *name, uint mode, uint bits, uint nodemax, uint pgblk) -{ -uint lvl, attr, cacheblk, last; -BtLock lockmode = BtLockWrite; -BtPage alloc; -off64_t size; -uint amt[1]; -BtDb* bt; - -#ifndef unix -SYSTEM_INFO sysinfo[1]; -#endif - -#ifdef unix - bt = malloc (sizeof(BtDb) + nodemax * sizeof(BtHash)); - memset (bt, 0, sizeof(BtDb)); - - switch (mode & 0x7fff) - { - case BT_fl: - case BT_rw: - bt->idx = open ((char*)name, O_RDWR | O_CREAT, 0666); - break; - - case BT_ro: - default: - bt->idx = open ((char*)name, O_RDONLY); - lockmode = BtLockRead; - break; - } - if( bt->idx == -1 ) - return free(bt), NULL; - - if( nodemax ) - cacheblk = 4096; // page size for unix - else - cacheblk = 0; - -#else - bt = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtDb) + nodemax * sizeof(BtHash)); - attr = FILE_ATTRIBUTE_NORMAL; - switch (mode & 0x7fff) - { - case BT_fl: - attr |= FILE_FLAG_WRITE_THROUGH | FILE_FLAG_NO_BUFFERING; - - case BT_rw: - bt->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL); - break; - - case BT_ro: - default: - bt->idx = CreateFile(name, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, attr, NULL); - lockmode = BtLockRead; - break; - } - if( bt->idx == INVALID_HANDLE_VALUE ) - return GlobalFree(bt), NULL; - - // normalize cacheblk to multiple of sysinfo->dwAllocationGranularity - GetSystemInfo(sysinfo); - - if( nodemax ) - cacheblk = sysinfo->dwAllocationGranularity; - else - cacheblk = 0; -#endif - - // determine sanity of page size - - if( bits > BT_maxbits ) - bits = BT_maxbits; - else if( bits < BT_minbits ) - bits = BT_minbits; - - if ( bt_lockpage(bt, ALLOC_page, lockmode) ) - return bt_close (bt), NULL; - -#ifdef unix - *amt = 0; - - // read minimum page size to get root info - - if( size = lseek (bt->idx, 0L, 2) ) { - alloc = malloc (BT_minpage); - pread(bt->idx, alloc, BT_minpage, 0); - bits = alloc->bits; - free (alloc); - } else if( mode == BT_ro ) - return bt_close (bt), NULL; -#else - size = GetFileSize(bt->idx, amt); - - if( size || *amt ) { - alloc = VirtualAlloc(NULL, BT_minpage, MEM_COMMIT, PAGE_READWRITE); - if( !ReadFile(bt->idx, (char *)alloc, BT_minpage, amt, NULL) ) - return bt_close (bt), NULL; - bits = alloc->bits; - VirtualFree (alloc, 0, MEM_RELEASE); - } else if( mode == BT_ro ) - return bt_close (bt), NULL; -#endif - - bt->page_size = 1 << bits; - bt->page_bits = bits; - - bt->nodemax = nodemax; - bt->mode = mode; - - // setup cache mapping - - if( cacheblk ) { - if( cacheblk < bt->page_size ) - cacheblk = bt->page_size; - - bt->hashsize = nodemax / 8; - bt->hashmask = (cacheblk >> bits) - 1; - bt->mapped_io = 1; - } - - // requested number of pages per memmap segment - - if( cacheblk ) - if( (1 << pgblk) > bt->hashmask ) - bt->hashmask = (1 << pgblk) - 1; - - bt->seg_bits = 0; - - while( (1 << bt->seg_bits) <= bt->hashmask ) - bt->seg_bits++; - -#ifdef unix - bt->mem = malloc (8 *bt->page_size); - bt->cache = calloc (bt->hashsize, sizeof(ushort)); -#else - bt->mem = VirtualAlloc(NULL, 8 * bt->page_size, MEM_COMMIT, PAGE_READWRITE); - bt->cache = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, bt->hashsize * sizeof(ushort)); -#endif - bt->frame = (BtPage)bt->mem; - bt->cursor = (BtPage)(bt->mem + bt->page_size); - bt->page = (BtPage)(bt->mem + 2 * bt->page_size); - bt->alloc = (BtPage)(bt->mem + 3 * bt->page_size); - bt->temp = (BtPage)(bt->mem + 4 * bt->page_size); - bt->temp2 = (BtPage)(bt->mem + 5 * bt->page_size); - bt->parent = (BtPage)(bt->mem + 6 * bt->page_size); - bt->zero = (BtPage)(bt->mem + 7 * bt->page_size); - - if( size || *amt ) { - if ( bt_unlockpage(bt, ALLOC_page, lockmode) ) - return bt_close (bt), NULL; - - return bt; - } - - // initializes an empty b-tree with root page and page of leaves - - memset (bt->alloc, 0, bt->page_size); - bt_putid(bt->alloc->right, MIN_lvl+1); - bt->alloc->bits = bt->page_bits; - -#ifdef unix - if( write (bt->idx, bt->alloc, bt->page_size) < bt->page_size ) - return bt_close (bt), NULL; -#else - if( !WriteFile (bt->idx, (char *)bt->alloc, bt->page_size, amt, NULL) ) - return bt_close (bt), NULL; - - if( *amt < bt->page_size ) - return bt_close (bt), NULL; -#endif - - memset (bt->frame, 0, bt->page_size); - bt->frame->bits = bt->page_bits; - bt->frame->posted = 1; - - for( lvl=MIN_lvl; lvl--; ) { - slotptr(bt->frame, 1)->off = offsetof(struct BtPage_, fence); - bt_putid(slotptr(bt->frame, 1)->id, lvl ? MIN_lvl - lvl + 1 : 0); // next(lower) page number - bt->frame->fence[0] = 2; - bt->frame->fence[1] = 0xff; - bt->frame->fence[2] = 0xff; - bt->frame->min = bt->page_size; - bt->frame->lvl = lvl; - bt->frame->cnt = 1; - bt->frame->act = 1; -#ifdef unix - if( write (bt->idx, bt->frame, bt->page_size) < bt->page_size ) - return bt_close (bt), NULL; -#else - if( !WriteFile (bt->idx, (char *)bt->frame, bt->page_size, amt, NULL) ) - return bt_close (bt), NULL; - - if( *amt < bt->page_size ) - return bt_close (bt), NULL; -#endif - } - - // create empty page area by writing last page of first - // cache area (other pages are zeroed by O/S) - - if( bt->mapped_io && bt->hashmask ) { - memset(bt->frame, 0, bt->page_size); - last = bt->hashmask; - - while( last < MIN_lvl + 1 ) - last += bt->hashmask + 1; -#ifdef unix - pwrite(bt->idx, bt->frame, bt->page_size, last << bt->page_bits); -#else - SetFilePointer (bt->idx, last << bt->page_bits, NULL, FILE_BEGIN); - if( !WriteFile (bt->idx, (char *)bt->frame, bt->page_size, amt, NULL) ) - return bt_close (bt), NULL; - if( *amt < bt->page_size ) - return bt_close (bt), NULL; -#endif - } - - if( bt_unlockpage(bt, ALLOC_page, lockmode) ) - return bt_close (bt), NULL; - - return bt; -} - -// compare two keys, returning > 0, = 0, or < 0 -// as the comparison value - -int keycmp (BtKey key1, unsigned char *key2, uint len2) -{ -uint len1 = key1->len; -int ans; - - if( ans = memcmp (key1->key, key2, len1 > len2 ? len2 : len1) ) - return ans; - - if( len1 > len2 ) - return 1; - if( len1 < len2 ) - return -1; - - return 0; -} - -// Update current page of btree by writing file contents -// or flushing mapped area to disk. - -BTERR bt_update (BtDb *bt, BtPage page, uid page_no) -{ -off64_t off = page_no << bt->page_bits; - -#ifdef unix - if ( !bt->mapped_io ) - if ( pwrite(bt->idx, page, bt->page_size, off) != bt->page_size ) - return bt->err = BTERR_wrt; -#else -uint amt[1]; - if ( !bt->mapped_io ) - { - SetFilePointer (bt->idx, (long)off, (long*)(&off)+1, FILE_BEGIN); - if( !WriteFile (bt->idx, (char *)page, bt->page_size, amt, NULL) ) - return GetLastError(), bt->err = BTERR_wrt; - - if( *amt < bt->page_size ) - return GetLastError(), bt->err = BTERR_wrt; - } - else if ( bt->mode == BT_fl ) { - FlushViewOfFile(page, bt->page_size); - FlushFileBuffers(bt->idx); - } -#endif - return 0; -} - -// find page in cache - -BtHash *bt_findhash(BtDb *bt, uid page_no) -{ -BtHash *hash; -uint idx; - - // compute cache block first page and hash idx - - page_no &= ~bt->hashmask; - idx = (uint)(page_no >> bt->seg_bits) % bt->hashsize; - - if( bt->cache[idx] ) - hash = bt->nodes + bt->cache[idx]; - else - return NULL; - - do if( hash->page_no == page_no ) - break; - while(hash = hash->hashnext ); - - return hash; -} - -// add page cache entry to hash index - -void bt_linkhash(BtDb *bt, BtHash *node, uid page_no) -{ -uint idx = (uint)(page_no >> bt->seg_bits) % bt->hashsize; -BtHash *hash; - - if( bt->cache[idx] ) { - node->hashnext = hash = bt->nodes + bt->cache[idx]; - hash->hashprev = node; - } - - node->hashprev = NULL; - bt->cache[idx] = (ushort)(node - bt->nodes); -} - -// remove cache entry from hash table - -void bt_unlinkhash(BtDb *bt, BtHash *node) -{ -uint idx = (uint)(node->page_no >> bt->seg_bits) % bt->hashsize; -BtHash *hash; - - // unlink node - if( hash = node->hashprev ) - hash->hashnext = node->hashnext; - else if( hash = node->hashnext ) - bt->cache[idx] = (ushort)(hash - bt->nodes); - else - bt->cache[idx] = 0; - - if( hash = node->hashnext ) - hash->hashprev = node->hashprev; -} - -// add cache page to lru chain and map pages - -BtPage bt_linklru(BtDb *bt, BtHash *hash, uid page_no) -{ -int flag; -off64_t off = (page_no & ~bt->hashmask) << bt->page_bits; -off64_t limit = off + ((bt->hashmask+1) << bt->page_bits); -BtHash *node; - - memset(hash, 0, sizeof(BtHash)); - hash->page_no = (page_no & ~bt->hashmask); - bt_linkhash(bt, hash, page_no); - - if( node = hash->lrunext = bt->lrufirst ) - node->lruprev = hash; - else - bt->lrulast = hash; - - bt->lrufirst = hash; - -#ifdef unix - flag = PROT_READ | ( bt->mode == BT_ro ? 0 : PROT_WRITE ); - hash->page = (BtPage)mmap (0, (bt->hashmask+1) << bt->page_bits, flag, MAP_SHARED, bt->idx, off); - if( hash->page == MAP_FAILED ) - return bt->err = BTERR_map, (BtPage)NULL; - -#else - flag = ( bt->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE ); - hash->hmap = CreateFileMapping(bt->idx, NULL, flag, (DWORD)(limit >> 32), (DWORD)limit, NULL); - if( !hash->hmap ) - return bt->err = BTERR_map, NULL; - - flag = ( bt->mode == BT_ro ? FILE_MAP_READ : FILE_MAP_WRITE ); - hash->page = MapViewOfFile(hash->hmap, flag, (DWORD)(off >> 32), (DWORD)off, (bt->hashmask+1) << bt->page_bits); - if( !hash->page ) - return bt->err = BTERR_map, NULL; -#endif - - return (BtPage)((char*)hash->page + ((uint)(page_no & bt->hashmask) << bt->page_bits)); -} - -// find or place requested page in page-cache -// return memory address where page is located. - -BtPage bt_hashpage(BtDb *bt, uid page_no) -{ -BtHash *hash, *node, *next; -BtPage page; - - // find page in cache and move to top of lru list - - if( hash = bt_findhash(bt, page_no) ) { - page = (BtPage)((char*)hash->page + ((uint)(page_no & bt->hashmask) << bt->page_bits)); - // swap node in lru list - if( node = hash->lruprev ) { - if( next = node->lrunext = hash->lrunext ) - next->lruprev = node; - else - bt->lrulast = node; - - if( next = hash->lrunext = bt->lrufirst ) - next->lruprev = hash; - else - return bt->err = BTERR_hash, (BtPage)NULL; - - hash->lruprev = NULL; - bt->lrufirst = hash; - } - return page; - } - - // map pages and add to cache entry - - if( bt->nodecnt < bt->nodemax ) { - hash = bt->nodes + ++bt->nodecnt; - return bt_linklru(bt, hash, page_no); - } - - // hash table is already full, replace last lru entry from the cache - - if( hash = bt->lrulast ) { - // unlink from lru list - if( node = bt->lrulast = hash->lruprev ) - node->lrunext = NULL; - else - return bt->err = BTERR_hash, (BtPage)NULL; - -#ifdef unix - munmap (hash->page, (bt->hashmask+1) << bt->page_bits); -#else - FlushViewOfFile(hash->page, 0); - UnmapViewOfFile(hash->page); - CloseHandle(hash->hmap); -#endif - // unlink from hash table - - bt_unlinkhash(bt, hash); - - // map and add to cache - - return bt_linklru(bt, hash, page_no); - } - - return bt->err = BTERR_hash, (BtPage)NULL; -} - -// map a btree page onto current page - -BTERR bt_mappage (BtDb *bt, BtPage *page, uid page_no) -{ -off64_t off = page_no << bt->page_bits; -#ifndef unix -int amt[1]; -#endif - - if( bt->mapped_io ) { - bt->err = 0; - *page = bt_hashpage(bt, page_no); - return bt->err; - } -#ifdef unix - if ( pread(bt->idx, *page, bt->page_size, off) < bt->page_size ) - return bt->err = BTERR_map; -#else - SetFilePointer (bt->idx, (long)off, (long*)(&off)+1, FILE_BEGIN); - - if( !ReadFile(bt->idx, *page, bt->page_size, amt, NULL) ) - return bt->err = BTERR_map; - - if( *amt < bt->page_size ) - return bt->err = BTERR_map; -#endif - return 0; -} - -// allocate a new page and write page into it - -uid bt_newpage(BtDb *bt, BtPage page) -{ -uid new_page; -char *pmap; -int reuse; - - // lock page zero - - if ( bt_lockpage(bt, ALLOC_page, BtLockWrite) ) - return 0; - - if( bt_mappage (bt, &bt->alloc, ALLOC_page) ) - return 0; - - // use empty chain first - // else allocate empty page - - if( new_page = bt_getid(bt->alloc[1].right) ) { - if( bt_mappage (bt, &bt->temp, new_page) ) - return 0; // don't unlock on error - memcpy(bt->alloc[1].right, bt->temp->right, BtId); - reuse = 1; - } else { - new_page = bt_getid(bt->alloc->right); - bt_putid(bt->alloc->right, new_page+1); - reuse = 0; - } - - if( bt_update(bt, bt->alloc, ALLOC_page) ) - return 0; // don't unlock on error - - if( !bt->mapped_io ) { - if( bt_update(bt, page, new_page) ) - return 0; //don't unlock on error - - // unlock page zero - - if ( bt_unlockpage(bt, ALLOC_page, BtLockWrite) ) - return 0; - - return new_page; - } - -#ifdef unix - if ( pwrite(bt->idx, page, bt->page_size, new_page << bt->page_bits) < bt->page_size ) - return bt->err = BTERR_wrt, 0; - - // if writing first page of hash block, zero last page in the block - - if ( !reuse && bt->hashmask > 0 && (new_page & bt->hashmask) == 0 ) - { - // use temp buffer to write zeros - memset(bt->zero, 0, bt->page_size); - if ( pwrite(bt->idx,bt->zero, bt->page_size, (new_page | bt->hashmask) << bt->page_bits) < bt->page_size ) - return bt->err = BTERR_wrt, 0; - } -#else - // bring new page into page-cache and copy page. - // this will extend the file into the new pages. - - if( !(pmap = (char*)bt_hashpage(bt, new_page & ~bt->hashmask)) ) - return 0; - - memcpy(pmap+((new_page & bt->hashmask) << bt->page_bits), page, bt->page_size); -#endif - - // unlock page zero - - if ( bt_unlockpage(bt, ALLOC_page, BtLockWrite) ) - return 0; - - return new_page; -} - -// find slot in page for given key at a given level -// return 0 if beyond fence value - -int bt_findslot (BtPageSet *set, unsigned char *key, uint len) -{ -uint diff, higher = set->page->cnt, low = 1, slot; - - // make stopper key an infinite fence value - - if( bt_getid (set->page->right) ) - higher++; - - // low is the lowest candidate, higher is already - // tested as .ge. the given key, loop ends when they meet - - while( diff = higher - low ) { - slot = low + ( diff >> 1 ); - if( keycmp (keyptr(set->page, slot), key, len) < 0 ) - low = slot + 1; - else - higher = slot; - } - - if( higher <= set->page->cnt ) - return higher; - - // if leaf page, compare against fence value - - // return zero if key is on right link page - // or return slot beyond last key - - if( set->page->lvl || keycmp ((BtKey)set->page->fence, key, len) < 0 ) - return 0; - - return higher; -} - -// find and load page at given level for given key -// leave page rd or wr locked as requested - -int bt_loadpage (BtDb *bt, BtPageSet *set, unsigned char *key, uint len, uint lvl, uint lock) -{ -uid page_no = ROOT_page, prevpage = 0; -uint drill = 0xff, slot; -uint mode, prevmode; - - // start at root of btree and drill down - - do { - // determine lock mode of drill level - mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead; - - set->page_no = page_no; - - // obtain access lock using lock chaining - - if( page_no > ROOT_page ) - if( bt_lockpage(bt, page_no, BtLockAccess) ) - return 0; - - if( prevpage ) - if( bt_unlockpage(bt, prevpage, prevmode) ) - return 0; - - // obtain read lock using lock chaining - - if( bt_lockpage(bt, page_no, mode) ) - return 0; - - if( page_no > ROOT_page ) - if( bt_unlockpage(bt, page_no, BtLockAccess) ) - return 0; - - // map/obtain page contents - - if( bt_mappage (bt, &set->page, page_no) ) - return 0; - - // re-read and re-lock root after determining actual level of root - - if( set->page->lvl != drill) { - if ( page_no != ROOT_page ) - return bt->err = BTERR_struct, 0; - - drill = set->page->lvl; - - if( lock == BtLockWrite && drill == lvl ) - if( bt_unlockpage(bt, page_no, mode) ) - return 0; - else - continue; - } - - prevpage = page_no; - prevmode = mode; - - // if page is being deleted and we should continue right - - if( set->page->kill && set->page->goright ) { - page_no = bt_getid (set->page->right); - continue; - } - - // otherwise, wait for deleted node to clear - - if( set->page->kill ) { - if( bt_unlockpage(bt, set->page_no, mode) ) - return bt->err; - page_no = ROOT_page; - prevpage = 0; - drill = 0xff; -#ifdef unix - sched_yield(); -#else - SwitchToThread(); -#endif - continue; - } - - // find key on page at this level - // and descend to requested level - - if( slot = bt_findslot (set, key, len) ) { - if( drill == lvl ) - return slot; - - if( slot > set->page->cnt ) - return bt->err = BTERR_struct, 0; - - // if drilling down, find next active key - - while( slotptr(set->page, slot)->dead ) - if( slot++ < set->page->cnt ) - continue; - else - return bt->err = BTERR_struct, 0; - - page_no = bt_getid(slotptr(set->page, slot)->id); - drill--; - continue; - } - - // or slide right into next page - // (slide left from deleted page) - - page_no = bt_getid(set->page->right); - - } while( page_no ); - - // return error on end of right chain - - bt->err = BTERR_struct; - return 0; // return error -} - -// drill down fixing fence values for left sibling tree - -// call with set write locked mapped to bt->temp -// return with set unlocked & unpinned. - -BTERR bt_fixfences (BtDb *bt, BtPageSet *set, unsigned char *newfence) -{ -unsigned char oldfence[256]; -BtPageSet next[1]; -uid right; -int chk; - - next->page_no = bt_getid(slotptr(set->page, set->page->cnt)->id); - memcpy (oldfence, set->page->fence, 256); - next->page = bt->temp2; - bt->temp2 = bt->temp; - bt->temp = next->page; - - while( !set->page->kill && set->page->lvl ) { - if( bt_lockpage (bt, next->page_no, BtLockParent) ) - return bt->err; - if( bt_lockpage (bt, next->page_no, BtLockAccess) ) - return bt->err; - if( bt_lockpage (bt, next->page_no, BtLockWrite) ) - return bt->err; - if( bt_unlockpage (bt, next->page_no, BtLockAccess) ) - return bt->err; - - if( bt_mappage (bt, &next->page, next->page_no) ) - return bt->err; - - chk = keycmp ((BtKey)next->page->fence, oldfence + 1, *oldfence); - - if( chk < 0 ) { - right = bt_getid (next->page->right); - if( bt_unlockpage (bt, next->page_no, BtLockWrite) ) - return bt->err; - if( bt_unlockpage (bt, next->page_no, BtLockParent) ) - return bt->err; - next->page_no = right; - continue; - } - - if( chk > 0 ) - return bt->err = BTERR_struct; - - if( bt_fixfences (bt, next, newfence) ) - return bt->err; - - break; - } - - set->page = bt->temp; - - if( bt_mappage (bt, &set->page, set->page_no) ) - return bt->err; - - memcpy (set->page->fence, newfence, 256); - - if( bt_update(bt, set->page, set->page_no) ) - return bt->err; - if( bt_unlockpage (bt, set->page_no, BtLockWrite) ) - return bt->err; - if( bt_unlockpage (bt, set->page_no, BtLockParent) ) - return bt->err; - return 0; -} - - -// return page to free list -// page must be delete & write locked - -BTERR bt_freepage (BtDb *bt, BtPageSet *set) -{ - // lock & map allocation page - - if( bt_lockpage (bt, ALLOC_page, BtLockWrite) ) - return bt->err; - - if( bt_mappage (bt, &bt->alloc, ALLOC_page) ) - return bt->err; - - // store chain in second right - bt_putid(set->page->right, bt_getid(bt->alloc[1].right)); - bt_putid(bt->alloc[1].right, set->page_no); - set->page->free = 1; - - if( bt_update(bt, bt->alloc, ALLOC_page) ) - return bt->err; - if( bt_update(bt, set->page, set->page_no) ) - return bt->err; - - // unlock page zero - - if( bt_unlockpage(bt, ALLOC_page, BtLockWrite) ) - return bt->err; - - // remove write lock on deleted node - - if( bt_unlockpage(bt, set->page_no, BtLockWrite) ) - return bt->err; - - return bt_unlockpage (bt, set->page_no, BtLockDelete); -} - -// remove the root level by promoting its only child - -BTERR bt_removeroot (BtDb *bt, BtPageSet *root, BtPageSet *child) -{ -uid next = 0; - - do { - if( next ) { - if( bt_lockpage (bt, next, BtLockDelete) ) - return bt->err; - if( bt_lockpage (bt, next, BtLockWrite) ) - return bt->err; - - if( bt_mappage (bt, &child->page, next) ) - return bt->err; - - child->page_no = next; - } - - memcpy (root->page, child->page, bt->page_size); - next = bt_getid (slotptr(child->page, child->page->cnt)->id); - - if( bt_freepage (bt, child) ) - return bt->err; - } while( root->page->lvl > 1 && root->page->cnt == 1 ); - - if( bt_update (bt, root->page, ROOT_page) ) - return bt->err; - - return bt_unlockpage (bt, ROOT_page, BtLockWrite); -} - -// pull right page over ourselves in simple merge - -BTERR bt_mergeright (BtDb *bt, BtPageSet *set, BtPageSet *parent, BtPageSet *right, uint slot, uint idx) -{ - // install ourselves as child page - // and delete ourselves from parent - - bt_putid (slotptr(parent->page, idx)->id, set->page_no); - slotptr(parent->page, slot)->dead = 1; - parent->page->act--; - - // collapse any empty slots - - while( idx = parent->page->cnt - 1 ) - if( slotptr(parent->page, idx)->dead ) { - *slotptr(parent->page, idx) = *slotptr(parent->page, idx + 1); - memset (slotptr(parent->page, parent->page->cnt--), 0, sizeof(BtSlot)); - } else - break; - - memcpy (set->page, right->page, bt->page_size); - - if( bt_unlockpage (bt, right->page_no, BtLockParent) ) - return bt->err; - - if( bt_freepage (bt, right) ) - return bt->err; - - // do we need to remove a btree level? - // (leave the first page of leaves alone) - - if( parent->page_no == ROOT_page && parent->page->cnt == 1 ) - if( set->page->lvl ) - return bt_removeroot (bt, parent, set); - - if( bt_update (bt, parent->page, parent->page_no) ) - return bt->err; - - if( bt_unlockpage (bt, parent->page_no, BtLockWrite) ) - return bt->err; - - if( bt_update (bt, set->page, set->page_no) ) - return bt->err; - - if( bt_unlockpage (bt, set->page_no, BtLockWrite) ) - return bt->err; - - if( bt_unlockpage (bt, set->page_no, BtLockDelete) ) - return bt->err; - - return 0; -} - -// remove both child and parent from the btree -// from the fence position in the parent - -BTERR bt_removeparent (BtDb *bt, BtPageSet *child, BtPageSet *parent, BtPageSet *right, BtPageSet *rparent, uint lvl) -{ -unsigned char pagefence[256]; -uint idx; - - // pull right sibling over ourselves and unlock - - memcpy (child->page, right->page, bt->page_size); - - if( bt_update(bt, child->page, child->page_no) ) - return bt->err; - - if( bt_unlockpage (bt, child->page_no, BtLockWrite) ) - return bt->err; - - // install ourselves into right link of old right page - - bt_putid (right->page->right, child->page_no); - right->page->goright = 1; // tell bt_loadpage to go right to us - right->page->kill = 1; - - if( bt_update(bt, right->page, right->page_no) ) - return bt->err; - - if( bt_unlockpage (bt, right->page_no, BtLockWrite) ) - return bt->err; - - // remove our slot from our parent - // signal to move right - - parent->page->goright = 1; // tell bt_findslot to go right to rparent - parent->page->kill = 1; - parent->page->act--; - - // redirect right page pointer in right parent to us - - for( idx = 0; idx++ < rparent->page->cnt; ) - if( !slotptr(rparent->page, idx)->dead ) - break; - - if( bt_getid (slotptr(rparent->page, idx)->id) != right->page_no ) - return bt->err = BTERR_struct; - - bt_putid (slotptr(rparent->page, idx)->id, child->page_no); - - if( bt_update (bt, rparent->page, rparent->page_no) ) - return bt->err; - - if( bt_unlockpage (bt, rparent->page_no, BtLockWrite) ) - return bt->err; - - // save parent page fence value - - memcpy (pagefence, parent->page->fence, 256); - - if( bt_update (bt, parent->page, parent->page_no) ) - return bt->err; - if( bt_unlockpage (bt, parent->page_no, BtLockWrite) ) - return bt->err; - - return bt_removepage (bt, parent->page_no, lvl, pagefence); -} - -// remove page from btree -// call with page unlocked -// returns with page on free list - -BTERR bt_removepage (BtDb *bt, uid page_no, uint lvl, unsigned char *pagefence) -{ -BtPageSet parent[1], rparent[1], sibling[1], set[1]; -unsigned char newfence[256]; -uint slot, idx; -BtKey ptr; - - parent->page = bt->parent; - set->page_no = page_no; - set->page = bt->page; - - // load and lock our parent - - while( 1 ) { - if( !(slot = bt_loadpage (bt, parent, pagefence+1, *pagefence, lvl+1, BtLockWrite)) ) - return bt->err; - - // wait until we are posted in our parent - - if( set->page_no != bt_getid (slotptr (parent->page, slot)->id) ) { - if( bt_unlockpage (bt, parent->page_no, BtLockWrite) ) - return bt->err; -#ifdef unix - sched_yield(); -#else - SwitchToThread(); -#endif - continue; - } - - // can we do a simple merge entirely - // between siblings on the parent page? - - if( slot < parent->page->cnt ) { - // find our right neighbor - // right must exist because the stopper prevents - // the rightmost page from deleting - - for( idx = slot; idx++ < parent->page->cnt; ) - if( !slotptr(parent->page, idx)->dead ) - break; - - sibling->page_no = bt_getid (slotptr (parent->page, idx)->id); - - if( bt_lockpage (bt, set->page_no, BtLockDelete) ) - return bt->err; - - if( bt_lockpage (bt, set->page_no, BtLockWrite) ) - return bt->err; - - if( bt_mappage (bt, &set->page, set->page_no) ) - return bt->err; - - // merge right if sibling shows up in - // our parent and is not being killed - - if( sibling->page_no == bt_getid (set->page->right) ) { - if( bt_lockpage (bt, sibling->page_no, BtLockParent) ) - return bt->err; - - if( bt_lockpage (bt, sibling->page_no, BtLockDelete) ) - return bt->err; - - if( bt_lockpage (bt, sibling->page_no, BtLockWrite) ) - return bt->err; - - sibling->page = bt->temp; - - if( bt_mappage (bt, &sibling->page, sibling->page_no) ) - return bt->err; - - if( !sibling->page->kill ) - return bt_mergeright(bt, set, parent, sibling, slot, idx); - - // try again later - - if( bt_unlockpage (bt, sibling->page_no, BtLockWrite) ) - return bt->err; - } - - if( bt_unlockpage (bt, set->page_no, BtLockDelete) ) - return bt->err; - - if( bt_unlockpage (bt, set->page_no, BtLockWrite) ) - return bt->err; - - if( bt_unlockpage (bt, parent->page_no, BtLockWrite) ) - return bt->err; -#ifdef linux - sched_yield (); -#else - SwitchToThread(); -#endif - continue; - } - - // find our left neighbor in our parent page - - for( idx = slot; --idx; ) - if( !slotptr(parent->page, idx)->dead ) - break; - - // if no left neighbor, delete ourselves and our parent - - if( !idx ) { - if( bt_lockpage (bt, set->page_no, BtLockAccess) ) - return bt->err; - - if( bt_lockpage (bt, set->page_no, BtLockWrite) ) - return bt->err; - - if( bt_unlockpage (bt, set->page_no, BtLockAccess) ) - return bt->err; - - if( bt_mappage (bt, &set->page, set->page_no) ) - return bt->err; - - rparent->page_no = bt_getid (parent->page->right); - rparent->page = bt->temp; - - if( bt_lockpage (bt, rparent->page_no, BtLockAccess) ) - return bt->err; - - if( bt_lockpage (bt, rparent->page_no, BtLockWrite) ) - return bt->err; - - if( bt_unlockpage (bt, rparent->page_no, BtLockAccess) ) - return bt->err; - - if( bt_mappage (bt, &rparent->page, rparent->page_no) ) - return bt->err; - - if( !rparent->page->kill ) { - sibling->page_no = bt_getid (set->page->right); - - if( bt_lockpage (bt, sibling->page_no, BtLockAccess) ) - return bt->err; - - if( bt_lockpage (bt, sibling->page_no, BtLockWrite) ) - return bt->err; - - if( bt_unlockpage (bt, sibling->page_no, BtLockAccess) ) - return bt->err; - - sibling->page = bt->temp2; - - if( bt_mappage (bt, &sibling->page, sibling->page_no) ) - return bt->err; - - if( !sibling->page->kill ) - return bt_removeparent (bt, set, parent, sibling, rparent, lvl+1); - - // try again later - - if( bt_unlockpage (bt, sibling->page_no, BtLockWrite) ) - return bt->err; - } - - if( bt_unlockpage (bt, set->page_no, BtLockWrite) ) - return bt->err; - - if( bt_unlockpage (bt, rparent->page_no, BtLockWrite) ) - return bt->err; - - if( bt_unlockpage (bt, parent->page_no, BtLockWrite) ) - return bt->err; -#ifdef linux - sched_yield(); -#else - SwitchToThread(); -#endif - continue; - } - - // redirect parent to our left sibling - // lock and map our left sibling's page - - sibling->page_no = bt_getid (slotptr(parent->page, idx)->id); - sibling->page = bt->temp; - - // wait our turn on fence key maintenance - - if( bt_lockpage(bt, sibling->page_no, BtLockParent) ) - return bt->err; - - if( bt_lockpage(bt, sibling->page_no, BtLockAccess) ) - return bt->err; - - if( bt_lockpage(bt, sibling->page_no, BtLockWrite) ) - return bt->err; - - if( bt_unlockpage(bt, sibling->page_no, BtLockAccess) ) - return bt->err; - - if( bt_mappage (bt, &sibling->page, sibling->page_no) ) - return bt->err; - - // wait until sibling is in our parent - - if( bt_getid (sibling->page->right) != set->page_no ) { - if( bt_unlockpage (bt, parent->page_no, BtLockWrite) ) - return bt->err; - if( bt_unlockpage (bt, sibling->page_no, BtLockWrite) ) - return bt->err; - if( bt_unlockpage (bt, sibling->page_no, BtLockParent) ) - return bt->err; -#ifdef linux - sched_yield(); -#else - SwitchToThread(); -#endif - continue; - } - - // map page being killed - - if( bt_lockpage (bt, set->page_no, BtLockDelete) ) - return bt->err; - - if( bt_lockpage (bt, set->page_no, BtLockWrite) ) - return bt->err; - - if( bt_mappage (bt, &set->page, set->page_no) ) - return bt->err; - - // delete our left sibling from parent - - slotptr(parent->page,idx)->dead = 1; - parent->page->dirty = 1; - parent->page->act--; - - // redirect our parent slot to our left sibling - - bt_putid (slotptr(parent->page, slot)->id, sibling->page_no); - memcpy (sibling->page->right, set->page->right, BtId); - - if( bt_update (bt, sibling->page, sibling->page_no) ) - return bt->err; - - // collapse dead slots from parent - - while( idx = parent->page->cnt - 1 ) - if( slotptr(parent->page, idx)->dead ) { - *slotptr(parent->page, idx) = *slotptr(parent->page, parent->page->cnt); - memset (slotptr(parent->page, parent->page->cnt--), 0, sizeof(BtSlot)); - } else - break; - - // update parent page - - if( bt_update (bt, parent->page, parent->page_no) ) - return bt->err; - - // free our original page - - if( bt_freepage (bt, set) ) - return bt->err; - - // go down the left node's fence keys to the leaf level - // and update the fence keys in each page - - memcpy (newfence, parent->page->fence, 256); - - if( bt_fixfences (bt, sibling, newfence) ) - return bt->err; - - // promote sibling as new root? - - if( parent->page_no == ROOT_page && parent->page->cnt == 1 ) - if( sibling->page->lvl ) { - if( bt_lockpage (bt, sibling->page_no, BtLockDelete) ) - return bt->err; - - if( bt_lockpage (bt, sibling->page_no, BtLockWrite) ) - return bt->err; - - if( bt_mappage (bt, &sibling->page, set->page_no) ) - return bt->err; - - return bt_removeroot (bt, parent, sibling); - } - - return bt_unlockpage (bt, parent->page_no, BtLockWrite); - } -} - -// find and delete key on page by marking delete flag bit -// when page becomes empty, delete it - -BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len) -{ -unsigned char pagefence[256]; -uint slot, found, idx; -BtPageSet set[1]; -BtKey ptr; - - set->page = bt->page; - - if( slot = bt_loadpage (bt, set, key, len, 0, BtLockWrite) ) - ptr = keyptr(set->page, slot); - else - return bt->err; - - // if key is found delete it, otherwise ignore request - - if( found = slot <= set->page->cnt ) - if( found = !keycmp (ptr, key, len) ) - if( found = slotptr(set->page, slot)->dead == 0 ) { - slotptr(set->page,slot)->dead = 1; - set->page->dirty = 1; - set->page->act--; - - // collapse empty slots - - 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; - } - - if( set->page->act ) { - if( bt_update(bt, set->page, set->page_no) ) - return bt->err; - bt->found = found; - return bt_unlockpage (bt, set->page_no, BtLockWrite); - } - - // delete page when empty - - memcpy (pagefence, set->page->fence, 256); - set->page->kill = 1; - - if( bt_update(bt, set->page, set->page_no) ) - return bt->err; - - if( bt_unlockpage(bt, set->page_no, BtLockWrite) ) - return bt->err; - - if( bt_removepage (bt, set->page_no, 0, pagefence) ) - return bt->err; - - 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; - - set->page = bt->page; - - 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 <= set->page->cnt ) - if( !keycmp (ptr, key, len) ) - id = bt_getid(slotptr(set->page,slot)->id); - - if ( bt_unlockpage(bt, set->page_no, BtLockRead) ) - return 0; - - return id; -} - -// check page for space available, -// clean if necessary and return -// 0 - page needs splitting -// >0 - new slot value - -uint bt_cleanpage(BtDb *bt, BtPage page, uint amt, uint slot) -{ -uint nxt = bt->page_size, off; -uint cnt = 0, idx = 0; -uint max = page->cnt; -uint newslot = max; -BtKey key; - - if( page->min >= (max+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 ) - return slot; - - // skip cleanup if nothing to reclaim - - if( !page->dirty ) - return 0; - - memcpy (bt->frame, page, bt->page_size); - - // skip page info and set rest of page to zero - - memset (page+1, 0, bt->page_size - sizeof(*page)); - page->dirty = 0; - page->act = 0; - - while( cnt++ < max ) { - if( cnt == slot ) - newslot = idx + 1; - if( slotptr(bt->frame,cnt)->dead ) - continue; - - off = slotptr(bt->frame,cnt)->off; - - // copy key - - if( off >= sizeof(*page) ) { - key = keyptr(bt->frame, cnt); - off = 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); - slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod; - slotptr(page, idx)->off = off; - page->act++; - } - page->min = nxt; - page->cnt = idx; - - if( page->min >= (idx+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 ) - return newslot; - - return 0; -} - -// split the root and raise the height of the btree - -BTERR bt_splitroot(BtDb *bt, BtPageSet *root, uid page_no2) -{ -unsigned char leftkey[256]; -uint nxt = bt->page_size; -uid new_page; - - // Obtain an empty page to use, and copy the current - // root contents into it, e.g. lower keys - - memcpy (leftkey, root->page->fence, 256); - root->page->posted = 1; - - if( !(new_page = bt_newpage(bt, root->page)) ) - return bt->err; - - // preserve the page info at the bottom - // of higher keys and set rest to zero - - memset(root->page+1, 0, bt->page_size - sizeof(*root->page)); - memset(root->page->fence, 0, 256); - root->page->fence[0] = 2; - root->page->fence[1] = 0xff; - root->page->fence[2] = 0xff; - - // insert new page fence key on newroot page - - nxt -= *leftkey + 1; - memcpy ((unsigned char *)root->page + nxt, leftkey, *leftkey + 1); - bt_putid(slotptr(root->page, 1)->id, new_page); - slotptr(root->page, 1)->off = nxt; - - // insert stopper key on newroot page - // and increase the root height - - bt_putid(slotptr(root->page, 2)->id, page_no2); - slotptr(root->page, 2)->off = offsetof(struct BtPage_, fence); - - 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++; - - // update and release root - - if( bt_update(bt, root->page, root->page_no) ) - return bt->err; - - return bt_unlockpage(bt, root->page_no, BtLockWrite); -} - -// split already locked full node -// return unlocked. - -BTERR bt_splitpage (BtDb *bt, BtPageSet *set) -{ -uint cnt = 0, idx = 0, max, nxt = bt->page_size, off; -unsigned char fencekey[256]; -uint lvl = set->page->lvl; -uid right; -BtKey key; - - // split higher half of keys to bt->frame - - memset (bt->frame, 0, bt->page_size); - max = set->page->cnt; - cnt = max / 2; - idx = 0; - - while( cnt++ < max ) { - if( !lvl || cnt < max ) { - key = keyptr(set->page, cnt); - off = nxt -= key->len + 1; - memcpy ((unsigned char *)bt->frame + nxt, key, key->len + 1); - } else - off = offsetof(struct BtPage_, fence); - - memcpy(slotptr(bt->frame,++idx)->id, slotptr(set->page,cnt)->id, BtId); - slotptr(bt->frame, idx)->tod = slotptr(set->page, cnt)->tod; - slotptr(bt->frame, idx)->off = off; - bt->frame->act++; - } - - if( set->page_no == ROOT_page ) - bt->frame->posted = 1; - - memcpy (bt->frame->fence, set->page->fence, 256); - bt->frame->bits = bt->page_bits; - bt->frame->min = nxt; - bt->frame->cnt = idx; - bt->frame->lvl = lvl; - - // link right node - - if( set->page_no > ROOT_page ) - memcpy (bt->frame->right, set->page->right, BtId); - - // get new free page and write higher keys to it. - - if( !(right = bt_newpage(bt, bt->frame)) ) - return bt->err; - - // update lower keys to continue in old page - - memcpy (bt->frame, set->page, bt->page_size); - memset (set->page+1, 0, bt->page_size - sizeof(*set->page)); - nxt = bt->page_size; - set->page->posted = 0; - set->page->dirty = 0; - set->page->act = 0; - cnt = 0; - idx = 0; - - // assemble page of smaller keys - - while( cnt++ < max / 2 ) { - key = keyptr(bt->frame, cnt); - - if( !lvl || cnt < max / 2 ) { - off = nxt -= key->len + 1; - memcpy ((unsigned char *)set->page + nxt, key, key->len + 1); - } else - off = offsetof(struct BtPage_, fence); - - 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 = off; - set->page->act++; - } - - // install fence key for smaller key page - - memset(set->page->fence, 0, 256); - memcpy(set->page->fence, key, key->len + 1); - - bt_putid(set->page->right, right); - set->page->min = nxt; - set->page->cnt = idx; - - // if current page is the root page, split it - - if( set->page_no == ROOT_page ) - return bt_splitroot (bt, set, right); - - if( bt_update (bt, set->page, set->page_no) ) - return bt->err; - - if( bt_unlockpage (bt, set->page_no, BtLockWrite) ) - return bt->err; - - // insert new fences in their parent pages - - while( 1 ) { - if( bt_lockpage (bt, set->page_no, BtLockParent) ) - return bt->err; - - if( bt_lockpage (bt, set->page_no, BtLockWrite) ) - return bt->err; - - if( bt_mappage (bt, &set->page, set->page_no) ) - return bt->err; - - memcpy (fencekey, set->page->fence, 256); - right = bt_getid (set->page->right); - - if( set->page->posted ) { - if( bt_unlockpage (bt, set->page_no, BtLockParent) ) - return bt->err; - - return bt_unlockpage (bt, set->page_no, BtLockWrite); - } - - set->page->posted = 1; - - if( bt_update (bt, set->page, set->page_no) ) - return bt->err; - - if( bt_unlockpage (bt, set->page_no, BtLockWrite) ) - return bt->err; - - if( bt_insertkey (bt, fencekey+1, *fencekey, lvl+1, set->page_no, time(NULL)) ) - return bt->err; - - if( bt_unlockpage (bt, set->page_no, BtLockParent) ) - return bt->err; - - if( !(set->page_no = right) ) - break; - } - - return 0; -} - -// Insert new key into the btree at requested level. - -BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uint lvl, uid id, uint tod) -{ -BtPageSet set[1]; -uint slot, idx; -BtKey ptr; - - set->page = bt->page; - - while( 1 ) { - if( slot = bt_loadpage (bt, set, key, len, lvl, BtLockWrite) ) - ptr = keyptr(set->page, slot); - else - { - if ( !bt->err ) - bt->err = BTERR_ovflw; - return bt->err; - } - - // if key already exists, update id and return - - if( slot <= set->page->cnt ) - if( !keycmp (ptr, key, len) ) { - 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); - - if ( bt_update(bt, set->page, set->page_no) ) - return bt->err; - - return bt_unlockpage(bt, set->page_no, BtLockWrite); - } - - // check if page has enough space - - if( slot = bt_cleanpage (bt, set->page, len, slot) ) - break; - - if( bt_splitpage (bt, set) ) - return bt->err; - } - - // 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 - - if( idx > set->page->cnt ) - 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; - - if( bt_update(bt, set->page, set->page_no) ) - return bt->err; - - return bt_unlockpage(bt, set->page_no, BtLockWrite); -} - -// cache page of keys into cursor and return starting slot for given key - -uint bt_startkey (BtDb *bt, unsigned char *key, uint len) -{ -BtPageSet set[1]; -uint slot; - - set->page = bt->page; - - // cache page for retrieval - if( slot = bt_loadpage (bt, set, key, len, 0, BtLockRead) ) - memcpy (bt->cursor, set->page, bt->page_size); - - bt->cursor_page = set->page_no; - - if ( bt_unlockpage(bt, set->page_no, BtLockRead) ) - return 0; - - return slot; -} - -// return next slot for cursor page -// or slide cursor right into next page - -uint bt_nextkey (BtDb *bt, uint slot) -{ -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)) // skip infinite stopper - return slot; - else - break; - - if( !right ) - break; - - bt->cursor_page = right; - set->page = bt->page; - - if( bt_lockpage(bt, right, BtLockRead) ) - return 0; - - if( bt_mappage (bt, &set->page, right) ) - break; - - memcpy (bt->cursor, set->page, bt->page_size); - - if( bt_unlockpage(bt, right, BtLockRead) ) - return 0; - - slot = 0; - } while( 1 ); - - return bt->err = 0; -} - -BtKey bt_key(BtDb *bt, uint slot) -{ - return keyptr(bt->cursor, slot); -} - -uid bt_uid(BtDb *bt, uint slot) -{ - return bt_getid(slotptr(bt->cursor,slot)->id); -} - -uint bt_tod(BtDb *bt, uint slot) -{ - return slotptr(bt->cursor,slot)->tod; -} - - -#ifdef STANDALONE -// standalone program to index file of keys -// then list them onto std-out - -int main (int argc, char **argv) -{ -uint slot, line = 0, off = 0, found = 0; -int dead, ch, cnt = 0, bits = 12; -unsigned char key[256]; -clock_t done, start; -uint pgblk = 0; -time_t tod[1]; -uint scan = 0; -uint len = 0; -uint map = 0; -BtKey ptr; -BtDb *bt; -FILE *in; - - if( argc < 4 ) { - fprintf (stderr, "Usage: %s idx_file src_file Read/Write/Scan/Delete/Find [page_bits mapped_pool_segments pages_per_segment start_line_number]\n", argv[0]); - fprintf (stderr, " page_bits: size of btree page in bits\n"); - fprintf (stderr, " mapped_pool_segments: size of buffer pool in segments\n"); - fprintf (stderr, " pages_per_segment: size of buffer pool segment in pages in bits\n"); - exit(0); - } - - start = clock(); - time(tod); - - if( argc > 4 ) - bits = atoi(argv[4]); - - if( argc > 5 ) - map = atoi(argv[5]); - - if( map > 65536 ) - fprintf (stderr, "Warning: buffer_pool > 65536 segments\n"); - - if( map && map < 8 ) - fprintf (stderr, "Buffer_pool too small\n"); - - if( argc > 6 ) - pgblk = atoi(argv[6]); - - if( bits + pgblk > 30 ) - fprintf (stderr, "Warning: very large buffer pool segment size\n"); - - if( argc > 7 ) - off = atoi(argv[7]); - - bt = bt_open ((argv[1]), BT_rw, bits, map, pgblk); - - if( !bt ) { - fprintf(stderr, "Index Open Error %s\n", argv[1]); - exit (1); - } - - switch(argv[3][0]| 0x20) - { - case 'w': - fprintf(stderr, "started indexing for %s\n", argv[2]); - if( argc > 2 && (in = fopen (argv[2], "rb")) ) - while( ch = getc(in), ch != EOF ) - if( ch == '\n' ) - { - if( off ) - sprintf((char *)key+len, "%.9d", line + off), len += 9; - - 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( len < 245 ) - key[len++] = ch; - fprintf(stderr, "finished adding keys, %d \n", line); - break; - - case 'd': - fprintf(stderr, "started deleting keys for %s\n", argv[2]); - if( argc > 2 && (in = fopen (argv[2], "rb")) ) - while( ch = getc(in), ch != EOF ) - if( ch == '\n' ) - { - if( off ) - sprintf((char *)key+len, "%.9d", line + off), len += 9; - line++; - if( bt_deletekey (bt, key, len) ) - fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0); - len = 0; - } - else if( len < 245 ) - key[len++] = ch; - fprintf(stderr, "finished deleting keys, %d \n", line); - break; - - case 'f': - fprintf(stderr, "started finding keys for %s\n", argv[2]); - if( argc > 2 && (in = fopen (argv[2], "rb")) ) - while( ch = getc(in), ch != EOF ) - if( ch == '\n' ) - { - if( off ) - sprintf((char *)key+len, "%.9d", line + off), len += 9; - line++; - if( bt_findkey (bt, key, len) ) - found++; - else if( bt->err ) - fprintf(stderr, "Error %d Syserr %d Line: %d\n", bt->err, errno, line), exit(0); - len = 0; - } - else if( len < 245 ) - key[len++] = ch; - fprintf(stderr, "finished search of %d keys, found %d\n", line, found); - break; - - case 's': - scan++; - break; - - } - - done = clock(); - fprintf(stderr, " Time to complete: %.2f seconds\n", (float)(done - start) / CLOCKS_PER_SEC); - - dead = cnt = 0; - 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) ) - if( cnt++, scan ) { - ptr = bt_key(bt, slot); - fwrite (ptr->key, ptr->len, 1, stdout); - fputc ('\n', stdout); - } - - fprintf(stderr, " Total keys read %d\n", cnt); - return 0; -} - -#endif //STANDALONE