--- /dev/null
+// btree version threadskv10h futex version
+// with reworked bt_deletekey code,
+// phase-fair re-entrant reader writer lock,
+// librarian page split code,
+// duplicate key management
+// bi-directional cursors
+// ACID batched key-value updates
+// LSM B-trees for write optimization
+// larger sized leaf pages than non-leaf
+// and LSM B-tree find & count operations
+
+// 15 DEC 2014
+
+// author: karl malbrain, malbrain@cal.berkeley.edu
+
+/*
+This work, including the source code, documentation
+and related data, is placed into the public domain.
+
+The orginal author is Karl Malbrain.
+
+THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
+OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
+MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
+ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
+RESULTING FROM THE USE, MODIFICATION, OR
+REDISTRIBUTION OF THIS SOFTWARE.
+*/
+
+// Please see the project home page for documentation
+// code.google.com/p/high-concurrency-btree
+
+#define _FILE_OFFSET_BITS 64
+#define _LARGEFILE64_SOURCE
+
+#ifdef linux
+#define _GNU_SOURCE
+#include <xmmintrin.h>
+#include <linux/futex.h>
+#include <sys/syscall.h>
+#endif
+
+#ifdef unix
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <sys/time.h>
+#include <sys/mman.h>
+#include <errno.h>
+#include <pthread.h>
+#include <limits.h>
+#else
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <fcntl.h>
+#include <process.h>
+#include <intrin.h>
+#endif
+
+#include <memory.h>
+#include <string.h>
+#include <stddef.h>
+
+typedef unsigned long long uid;
+typedef unsigned long long logseqno;
+
+#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_maxbits 26 // maximum page size in bits
+#define BT_minbits 9 // minimum page size in bits
+#define BT_minpage (1 << BT_minbits) // minimum page size
+#define BT_maxpage (1 << BT_maxbits) // maximum page size
+
+// BTree page number constants
+#define ALLOC_page 0 // allocation page
+#define ROOT_page 1 // root of the btree
+#define LATCH_page 2 // first page of latches
+
+#define SEG_bits 16 // number of leaf pages in a segment in bits
+#define MIN_seg 32 // initial number of mapping segments
+
+// Number of levels to create in a new BTree
+#define MIN_lvl 2
+
+/*
+There are six lock types for each node in four 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.
+6. (set 4) LinkModification: Exclusive. Update of a node's left link is underway. Incompatible with another LinkModification.
+*/
+
+typedef enum{
+ BtLockAccess = 1,
+ BtLockDelete = 2,
+ BtLockRead = 4,
+ BtLockWrite = 8,
+ BtLockParent = 16,
+ BtLockLink = 32
+} BtLock;
+
+typedef struct {
+ union {
+ struct {
+ volatile unsigned char xcl[1];
+ volatile unsigned char filler;
+ volatile ushort waiters[1];
+ } bits[1];
+ uint value[1];
+ };
+} MutexLatch;
+
+// definition for reader/writer reentrant lock implementation
+
+typedef struct {
+ MutexLatch xcl[1];
+ MutexLatch wrt[1];
+ ushort readers; // number of readers holding lock
+#ifdef DEBUG
+ ushort line; // owner source line number
+#endif
+ ushort dup; // re-entrant lock count
+ pid_t tid; // owner pid
+} RWLock;
+
+// hash table entries
+
+typedef struct {
+ MutexLatch latch[1];
+ uint entry; // Latch table entry at head of chain
+} BtHashEntry;
+
+// latch manager table structure
+
+typedef struct {
+ uid page_no; // latch set page number
+ MutexLatch modify[1]; // modify entry lite latch
+ RWLock readwr[1]; // read/write page lock
+ RWLock access[1]; // Access Intent/Page delete
+ RWLock parent[1]; // Posting of fence key in parent
+ RWLock link[1]; // left link update in progress
+ uint split; // right split page atomic insert
+ uint next; // next entry in hash table chain
+ uint prev; // prev entry in hash table chain
+ uint pin; // number of accessing threads
+} BtLatchSet;
+
+// Define the length of the page record numbers
+
+#define BtId 6
+
+// Page key slot definition.
+
+// Keys are marked dead, but remain on the page until
+// it cleanup is called. The fence key (highest key) for
+// a leaf page is always present, even after cleanup.
+
+// Slot types
+
+// In addition to the Unique keys that occupy slots
+// there are Librarian and Duplicate key
+// slots occupying the key slot array.
+
+// The Librarian slots are dead keys that
+// serve as filler, available to add new Unique
+// or Dup slots that are inserted into the B-tree.
+
+// The Duplicate slots have had their key bytes extended
+// by 6 bytes to contain a binary duplicate key uniqueifier.
+
+typedef enum {
+ Unique,
+ Update,
+ Librarian,
+ Duplicate,
+ Delete
+} BtSlotType;
+
+typedef struct {
+ uint off:BT_maxbits; // page offset for key start
+ uint type:3; // type of slot
+ uint dead:1; // set for deleted slot
+} BtSlot;
+
+// The key structure occupies space at the upper end of
+// each page. It's a length byte followed by the key
+// bytes.
+
+typedef struct {
+ unsigned char len; // this can be changed to a ushort or uint
+ unsigned char key[0];
+} BtKey;
+
+// the value structure also occupies space at the upper
+// end of the page. Each key is immediately followed by a value.
+
+typedef struct {
+ unsigned char len; // this can be changed to a ushort or uint
+ unsigned char value[0];
+} BtVal;
+
+#define BT_maxkey 255 // maximum number of bytes in a key
+#define BT_keyarray (BT_maxkey + sizeof(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/value offset
+ uint fence; // page fence key offset
+ uint garbage; // page garbage in bytes
+ unsigned char lvl; // level of page, zero = leaf
+ unsigned char free; // page is on the free chain
+ unsigned char kill; // page is being deleted
+ unsigned char nopromote; // page is being constructed
+ uid right, left; // page numbers to right and left
+} *BtPage;
+
+// The loadpage interface object
+
+typedef struct {
+ BtPage page; // current page pointer
+ BtLatchSet *latch; // current page latch set
+} BtPageSet;
+
+// structure for latch manager on shared ALLOC_page
+
+typedef struct {
+ uid allocpage; // page number of first available page
+ uid freechain; // head of free page_nos chain
+ uid leafchain; // head of leaf page_nos chain
+ uid leaf_page; // page number of leftmost leaf
+ uid rightleaf; // page number of rightmost leaf
+ uid leafpromote; // next leaf page to try promotion
+ unsigned long long leafpages; // number of active leaf pages
+ unsigned long long upperpages; // number of active upper pages
+ unsigned char leaf_xtra; // leaf page size in xtra bits
+ unsigned char page_bits; // base page size in bits
+ uint nlatchpage; // size of buffer pool & latchsets
+ uint latchtotal; // number of page latch entries
+ uint latchvictim; // next latch entry to test for pin
+ uint latchhash; // number of latch hash table slots
+ MutexLatch lock[1]; // allocation area lite latch
+ MutexLatch promote[1]; // promotion lite latch
+} BtPageZero;
+
+// The object structure for Btree access
+
+typedef struct {
+ uint page_size; // base page size
+ uint page_bits; // base page size in bits
+ uint leaf_xtra; // leaf xtra bits
+#ifdef unix
+ int idx;
+#else
+ HANDLE idx;
+#endif
+ BtPageZero *pagezero; // mapped allocation page
+ BtHashEntry *hashtable; // the buffer pool hash table entries
+ BtLatchSet *latchsets; // mapped latch set from buffer pool
+ uint maxleaves; // leaf page count to begin promote
+ int err; // last error
+ int line; // last error line no
+ int found; // number of keys found by delete
+ int type; // type of LSM tree 0=cache, 1=main
+ uint maxseg; // max number of memory mapped segments
+ uint segments; // number of memory mapped segments in use
+ MutexLatch maps[1]; // segment table mutex
+ unsigned char **pages; // memory mapped segments of b-tree
+} BtMgr;
+
+typedef struct {
+ BtMgr *mgr; // buffer manager for entire process
+ BtMgr *main; // buffer manager for main btree
+ pid_t tid; // thread-id of thread
+ BtPageSet cacheset[1]; // cached page frame for cache btree
+ BtPageSet mainset[1]; // cached page frame for main btree
+ uint cacheslot; // slot number in cacheset
+ uint mainslot; // slot number in mainset
+ ushort phase; // 1 = main btree 0 = cache btree 2 = both
+ BtSlot *cachenode;
+ BtSlot *mainnode;
+ BtKey *cachekey;
+ BtKey *mainkey;
+ BtVal *cacheval;
+ BtVal *mainval;
+} BtDb;
+
+typedef struct {
+ uint entry:31; // latch table entry number
+ uint reuse:1; // reused previous page
+ uint slot; // slot on page
+ uint src; // source slot
+} AtomicTxn;
+
+// Catastrophic errors
+
+typedef enum {
+ BTERR_ok = 0,
+ BTERR_struct,
+ BTERR_ovflw,
+ BTERR_lock,
+ BTERR_map,
+ BTERR_read,
+ BTERR_wrt,
+ BTERR_atomic
+} BTERR;
+
+// B-Tree functions
+
+extern void bt_close (BtDb *bt);
+extern BtDb *bt_open (BtMgr *mgr, BtMgr *main);
+extern BTERR bt_writepage (BtMgr *mgr, BtPage page, uid page_no, uint leaf);
+extern void bt_lockpage(BtLock mode, BtLatchSet *latch, pid_t tid, uint line);
+extern void bt_unlockpage(BtLock mode, BtLatchSet *latch, uint line);
+extern BTERR bt_insertkey (BtMgr *mgr, unsigned char *key, uint len, uint lvl, void *value, uint vallen, BtSlotType type);
+extern BTERR bt_deletekey (BtMgr *mgr, unsigned char *key, uint len, uint lvl);
+
+extern int bt_findkey (BtDb *db, unsigned char *key, uint keylen, unsigned char *value, uint valmax);
+
+extern BTERR bt_startkey (BtDb *db, unsigned char *key, uint len);
+extern BTERR bt_nextkey (BtDb *bt);
+
+extern uint bt_lastkey (BtDb *bt);
+extern uint bt_prevkey (BtDb *bt);
+
+// manager functions
+extern BtMgr *bt_mgr (char *name, uint bits, uint leaf_xtra, uint poolsize);
+extern void bt_mgrclose (BtMgr *mgr);
+
+// atomic transaction functions
+BTERR bt_atomicexec(BtMgr *mgr, BtPage source, uint count, pid_t tid);
+BTERR bt_promote (BtDb *bt);
+
+// The page is allocated from low and hi ends.
+// The key slots are allocated from the bottom,
+// while the text and value of the key
+// are 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 - 65535), and up to 253 bytes
+// of key value.
+
+// Associated with each key is a value byte string
+// containing any value desired.
+
+// 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 next
+// 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. The fence key for a leaf node is
+// always present
+
+// 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. It also
+// contains the latch manager hash table.
+
+// The ParentModification lock on a node is obtained to serialize posting
+// or changing the fence key for a node.
+
+// Empty pages are chained together through the ALLOC page and reused.
+
+// Access macros to address slot and key values from the page
+// Page slots use 1 based indexing.
+
+#define slotptr(page, slot) (((BtSlot *)(page+1)) + ((slot)-1))
+#define keyptr(page, slot) ((BtKey*)((unsigned char*)(page) + slotptr(page, slot)->off))
+#define valptr(page, slot) ((BtVal*)(keyptr(page,slot)->key + keyptr(page,slot)->len))
+#define fenceptr(page) ((BtKey*)((unsigned char*)(page) + page->fence))
+
+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;
+}
+
+// lite weight spin lock Latch Manager
+
+pid_t sys_gettid ()
+{
+ return syscall(SYS_gettid);
+}
+
+int sys_futex(void *addr1, int op, int val1, struct timespec *timeout, void *addr2, int val3)
+{
+ return syscall(SYS_futex, addr1, op, val1, timeout, addr2, val3);
+}
+
+void bt_mutexlock(MutexLatch *latch)
+{
+uint idx, waited = 0;
+MutexLatch prev[1];
+
+ while( 1 ) {
+ for( idx = 0; idx < 100; idx++ ) {
+ *prev->value = __sync_fetch_and_or (latch->value, 1);
+ if( !*prev->bits->xcl ) {
+ if( waited )
+ __sync_fetch_and_sub (latch->bits->waiters, 1);
+ return;
+ }
+ }
+
+ if( !waited ) {
+ __sync_fetch_and_add (latch->bits->waiters, 1);
+ *prev->bits->waiters += 1;
+ waited++;
+ }
+
+ sys_futex (latch->value, FUTEX_WAIT_PRIVATE, *prev->value, NULL, NULL, 0);
+ }
+}
+
+int bt_mutextry(MutexLatch *latch)
+{
+ return !__sync_lock_test_and_set (latch->bits->xcl, 1);
+}
+
+void bt_releasemutex(MutexLatch *latch)
+{
+MutexLatch prev[1];
+
+ *prev->value = __sync_fetch_and_and (latch->value, 0xffff0000);
+
+ if( *prev->bits->waiters )
+ sys_futex( latch->value, FUTEX_WAKE_PRIVATE, 1, NULL, NULL, 0 );
+}
+
+// reader/writer lock implementation
+
+void WriteLock (RWLock *lock, pid_t tid, uint line)
+{
+ if( tid && lock->tid == tid ) {
+ lock->dup++;
+ return;
+ }
+ bt_mutexlock (lock->xcl);
+ bt_mutexlock (lock->wrt);
+ bt_releasemutex (lock->xcl);
+ lock->tid = tid;
+#ifdef DEBUG
+ lock->line = line;
+#endif
+}
+
+void WriteRelease (RWLock *lock)
+{
+ if( lock->dup ) {
+ lock->dup--;
+ return;
+ }
+ lock->tid = 0;
+ bt_releasemutex (lock->wrt);
+}
+
+void ReadLock (RWLock *lock)
+{
+ bt_mutexlock (lock->xcl);
+
+ if( !__sync_fetch_and_add (&lock->readers, 1) )
+ bt_mutexlock (lock->wrt);
+
+ bt_releasemutex (lock->xcl);
+}
+
+void ReadRelease (RWLock *lock)
+{
+ if( __sync_fetch_and_sub (&lock->readers, 1) == 1 )
+ bt_releasemutex (lock->wrt);
+}
+
+// read page into buffer pool from permanent location in Btree file
+
+BTERR bt_readpage (BtMgr *mgr, BtPage page, uid page_no, uint leaf)
+{
+uint page_size = mgr->page_size;
+
+ if( leaf )
+ page_size <<= mgr->leaf_xtra;
+
+ if( pread(mgr->idx, page, page_size, page_no << mgr->page_bits) < page_size )
+ return mgr->err = BTERR_read;
+
+ return 0;
+}
+
+// write page to location in Btree file
+
+BTERR bt_writepage (BtMgr *mgr, BtPage page, uid page_no, uint leaf)
+{
+uint page_size = mgr->page_size;
+
+ if( leaf )
+ page_size <<= mgr->leaf_xtra;
+
+ if( pwrite(mgr->idx, page, page_size, page_no << mgr->page_bits) < page_size )
+ return mgr->err = BTERR_wrt;
+
+ return 0;
+}
+
+// decrement pin count
+
+void bt_unpinlatch (BtLatchSet *latch)
+{
+ bt_mutexlock(latch->modify);
+ latch->pin--;
+ bt_releasemutex(latch->modify);
+}
+
+// return the btree cached page address
+
+BtPage bt_mappage (BtMgr *mgr, BtLatchSet *latch)
+{
+uint segment = latch->page_no >> SEG_bits;
+int flag = PROT_READ | PROT_WRITE;
+uid mask = (uid)1 << SEG_bits;
+BtPage page;
+
+ bt_mutexlock (mgr->maps);
+ mask--;
+
+ while( 1 ) {
+ if( segment < mgr->segments ) {
+ page = (BtPage)(mgr->pages[segment] + ((latch->page_no & mask) << mgr->page_bits));
+
+ bt_releasemutex (mgr->maps);
+ return page;
+ }
+
+ if( mgr->segments < mgr->maxseg ) {
+ mgr->pages[mgr->segments] = mmap (0, (uid)mgr->page_size << SEG_bits, flag, MAP_SHARED, mgr->idx, (uid)mgr->segments << mgr->page_bits << SEG_bits);
+ mgr->segments++;
+ continue;
+ }
+
+ mgr->maxseg <<= 1;
+ mgr->pages = realloc (mgr->pages, mgr->maxseg * sizeof(void *));
+ }
+}
+
+// return next available latch entry
+// and with latch entry locked
+
+uint bt_availnext (BtMgr *mgr)
+{
+BtLatchSet *latch;
+uint entry;
+
+ while( 1 ) {
+#ifdef unix
+ entry = __sync_fetch_and_add (&mgr->pagezero->latchvictim, 1) + 1;
+#else
+ entry = _InterlockedIncrement (&mgr->pagezero->latchvictim);
+#endif
+ entry %= mgr->pagezero->latchtotal;
+
+ if( !entry )
+ continue;
+
+ latch = mgr->latchsets + entry;
+
+ if( !bt_mutextry(latch->modify) )
+ continue;
+
+ // return this entry if it is not pinned
+
+ if( !latch->pin )
+ return entry;
+
+ bt_releasemutex(latch->modify);
+ }
+}
+
+// pin latch in latch pool
+
+BtLatchSet *bt_pinlatch (BtMgr *mgr, uid page_no)
+{
+uint hashidx = page_no % mgr->pagezero->latchhash;
+uint entry, oldidx;
+BtLatchSet *latch;
+BtPage page;
+
+ // try to find our entry
+
+ bt_mutexlock(mgr->hashtable[hashidx].latch);
+
+ if( entry = mgr->hashtable[hashidx].entry ) do
+ {
+ latch = mgr->latchsets + entry;
+
+ if( page_no == latch->page_no )
+ break;
+ } while( entry = latch->next );
+
+ // found our entry: increment pin
+
+ if( entry ) {
+ latch = mgr->latchsets + entry;
+ bt_mutexlock(latch->modify);
+ latch->pin++;
+ bt_releasemutex(latch->modify);
+ bt_releasemutex(mgr->hashtable[hashidx].latch);
+ return latch;
+ }
+
+ // find and reuse unpinned entry
+
+trynext:
+ entry = bt_availnext (mgr);
+ latch = mgr->latchsets + entry;
+ oldidx = latch->page_no % mgr->pagezero->latchhash;
+
+ // skip over this entry if latch not available
+
+ if( latch->page_no )
+ if( oldidx != hashidx )
+ if( !bt_mutextry (mgr->hashtable[oldidx].latch) ) {
+ bt_releasemutex(latch->modify);
+ goto trynext;
+ }
+
+ // if latch is on a different hash chain
+ // unlink from the old page_no chain
+
+ if( latch->page_no )
+ if( oldidx != hashidx ) {
+ if( latch->prev )
+ mgr->latchsets[latch->prev].next = latch->next;
+ else
+ mgr->hashtable[oldidx].entry = latch->next;
+
+ if( latch->next )
+ mgr->latchsets[latch->next].prev = latch->prev;
+
+ bt_releasemutex (mgr->hashtable[oldidx].latch);
+ }
+
+ // link page as head of hash table chain
+ // if this is a never before used entry,
+ // or it was previously on a different
+ // hash table chain. Otherwise, just
+ // leave it in its current hash table
+ // chain position.
+
+ if( !latch->page_no || hashidx != oldidx ) {
+ if( latch->next = mgr->hashtable[hashidx].entry )
+ mgr->latchsets[latch->next].prev = entry;
+
+ mgr->hashtable[hashidx].entry = entry;
+ latch->prev = 0;
+ }
+
+ // fill in latch structure
+
+ latch->page_no = page_no;
+ latch->pin = 1;
+
+ bt_releasemutex (latch->modify);
+ bt_releasemutex (mgr->hashtable[hashidx].latch);
+ return latch;
+}
+
+void bt_mgrclose (BtMgr *mgr)
+{
+char *name = mgr->type ? "Main" : "Cache";
+BtLatchSet *latch;
+uint num = 0;
+BtPage page;
+uint entry;
+
+ // flush previously written dirty pages
+ // and write recovery buffer to disk
+
+ fdatasync (mgr->idx);
+
+#ifdef unix
+ while( mgr->segments )
+ munmap (mgr->pages[--mgr->segments], (uid)mgr->page_size << SEG_bits);
+#else
+ while( mgr->segments ) {
+ FlushViewOfFile(mgr->pages[--mgr->segments], 0);
+ UnmapViewOfFile(mgr->pages[mgr->Segments]);
+ }
+#endif
+#ifdef unix
+ close (mgr->idx);
+ free (mgr);
+#else
+ FlushFileBuffers(mgr->idx);
+ CloseHandle(mgr->idx);
+ GlobalFree (mgr);
+#endif
+}
+
+// close and release memory
+
+void bt_close (BtDb *bt)
+{
+ free (bt);
+}
+
+void bt_initpage (BtMgr *mgr, BtPage page, uid leaf_page_no, uint lvl)
+{
+BtSlot *node = slotptr(page, 1);
+unsigned char value[BtId];
+uid page_no;
+BtKey* key;
+BtVal *val;
+
+ page_no = lvl ? ROOT_page : leaf_page_no;
+ node->off = mgr->page_size;
+
+ if( !lvl )
+ node->off <<= mgr->leaf_xtra;
+
+ node->off -= 3 + (lvl ? BtId + sizeof(BtVal): sizeof(BtVal));
+ node->type = Librarian;
+ node++->dead = 1;
+
+ node->off = node[-1].off;
+ key = keyptr(page, 2);
+ key = keyptr(page, 1);
+ key->len = 2; // create stopper key
+ key->key[0] = 0xff;
+ key->key[1] = 0xff;
+
+ bt_putid(value, leaf_page_no);
+ val = valptr(page, 1);
+ val->len = lvl ? BtId : 0;
+ memcpy (val->value, value, val->len);
+
+ page->min = node->off;
+ page->lvl = lvl;
+ page->cnt = 2;
+ page->act = 1;
+
+ if( bt_writepage (mgr, page, page_no, !lvl) ) {
+ fprintf (stderr, "Unable to create btree page %d\n", page_no);
+ exit(0);
+ }
+}
+
+// open/create new btree buffer manager
+
+// call with file_name, BT_openmode, bits in page size (e.g. 16),
+// extra bits for leaves (e.g. 4) size of latch pool (e.g. 500)
+
+BtMgr *bt_mgr (char *name, uint pagebits, uint leafxtra, uint nodemax)
+{
+uint lvl, attr, last, slot, idx, blk;
+int flag, initit = 0;
+BtPageZero *pagezero;
+BtLatchSet *latch;
+uid leaf_page;
+off64_t size;
+BtPage page;
+uint amt[1];
+BtMgr* mgr;
+
+ // determine sanity of page size and buffer pool
+
+ if( leafxtra | pagebits )
+ if( leafxtra + pagebits > BT_maxbits )
+ fprintf (stderr, "pagebits + leafxtra > maxbits\n"), exit(1);
+
+ if( pagebits )
+ if( pagebits < BT_minbits )
+ fprintf (stderr, "pagebits < minbits\n"), exit(1);
+
+#ifdef unix
+ mgr = calloc (1, sizeof(BtMgr));
+
+ mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
+
+ if( mgr->idx == -1 ) {
+ fprintf (stderr, "Unable to create/open btree file %s\n", name);
+ return free(mgr), NULL;
+ }
+#else
+ mgr = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtMgr));
+ attr = FILE_ATTRIBUTE_NORMAL;
+ mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
+
+ if( mgr->idx == INVALID_HANDLE_VALUE ) {
+ fprintf (stderr, "Unable to create/open btree file %s\n", name);
+ return GlobalFree(mgr), NULL;
+ }
+#endif
+
+#ifdef unix
+ pagezero = valloc (BT_maxpage);
+ page = (BtPage)pagezero;
+ *amt = 0;
+
+ // read minimum page size to get root info
+ // to support raw disk partition files
+ // check if page_bits == 0 on the disk.
+
+ if( size = lseek (mgr->idx, 0L, 2) )
+ if( pread(mgr->idx, pagezero, BT_minpage, 0) == BT_minpage )
+ if( pagezero->page_bits ) {
+ pagebits = pagezero->page_bits;
+ leafxtra = pagezero->leaf_xtra;
+ } else
+ initit = 1;
+ else
+ return free(mgr), free(pagezero), NULL;
+ else
+ initit = 1;
+#else
+ pagezero = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
+ size = GetFileSize(mgr->idx, amt);
+
+ if( size || *amt ) {
+ if( !ReadFile(mgr->idx, (char *)pagezero, BT_minpage, amt, NULL) )
+ return bt_mgrclose (mgr), NULL;
+ pagebits = pagezero->page_bits;
+ leafxtra = pagezero->leaf_xtra;
+ } else
+ initit = 1;
+#endif
+
+ mgr->page_size = 1 << pagebits;
+ mgr->page_bits = pagebits;
+ mgr->leaf_xtra = leafxtra;
+
+ if( !initit )
+ goto mgrlatch;
+
+ // calculate number of latch table & hash entries
+
+ memset (pagezero, 0, 1 << pagebits);
+ pagezero->nlatchpage = nodemax/16 * sizeof(BtHashEntry);
+
+ pagezero->nlatchpage += sizeof(BtLatchSet) * nodemax + mgr->page_size - 1;
+ pagezero->nlatchpage >>= mgr->page_bits;
+ pagezero->latchtotal = nodemax;
+
+ pagezero->latchhash = (((uid)pagezero->nlatchpage<< mgr->page_bits) - nodemax * sizeof(BtLatchSet)) / sizeof(BtHashEntry);
+
+ // initialize an empty b-tree with alloc page, root page, leaf page
+ // and page(s) of latches and page pool cache
+
+ pagezero->page_bits = mgr->page_bits;
+ pagezero->leaf_xtra = leafxtra;
+ pagezero->upperpages = 1;
+ pagezero->leafpages = 1;
+
+ leaf_page = pagezero->leaf_page = pagezero->nlatchpage + LATCH_page;
+
+ // round first leafpage up to leafxtra boundary
+
+ if( pagezero->leaf_page & ((1 << leafxtra) - 1)) {
+ blk = pagezero->leaf_page;
+ pagezero->leaf_page |= (1 << leafxtra) - 1;
+ pagezero->freechain = pagezero->leaf_page++;
+ leaf_page = pagezero->leaf_page;
+ } else
+ blk = 0;
+
+ pagezero->rightleaf = pagezero->leaf_page;
+ pagezero->allocpage = pagezero->leaf_page + (1 << leafxtra);
+
+ if( pwrite (mgr->idx, pagezero, 1 << pagebits, 0) < 1 << pagebits) {
+ fprintf (stderr, "Unable to create btree page zero\n");
+ return bt_mgrclose (mgr), NULL;
+ }
+
+ // initialize root level 1 page
+
+ memset (page, 0, 1 << pagebits);
+ bt_initpage (mgr, page, leaf_page, 1);
+
+ // chain unused pages as first freelist
+
+ memset (page, 0, 1 << pagebits);
+
+ while( blk & ((1 << leafxtra) - 1) ) {
+ if( bt_writepage (mgr, page, blk, 0) ) {
+ fprintf(stderr, "unable to write initial free blk %d\r\n", blk);
+ exit(1);
+ }
+ page->right = blk++;
+ }
+
+ // initialize first page of leaves
+
+ memset (page, 0, 1 << pagebits);
+ bt_initpage (mgr, page, leaf_page, 0);
+
+mgrlatch:
+#ifdef unix
+ free (pagezero);
+#else
+ VirtualFree (pagezero, 0, MEM_RELEASE);
+#endif
+
+ // map first segment
+
+ mgr->segments = 1;
+ mgr->maxseg = MIN_seg;
+ mgr->pages = calloc (MIN_seg, sizeof(unsigned char *));
+
+ flag = PROT_READ | PROT_WRITE;
+ mgr->pages[0] = mmap (0, (uid)mgr->page_size << SEG_bits, flag, MAP_SHARED, mgr->idx, 0);
+
+ if( mgr->pages[0] == MAP_FAILED ) {
+ fprintf (stderr, "Unable to mmap pagezero btree segment, error = %d\n", errno);
+ return bt_mgrclose (mgr), NULL;
+ }
+
+ mgr->pagezero = (BtPageZero *)mgr->pages[0];
+ mlock (mgr->pagezero, mgr->page_size);
+
+ // allocate latch pool
+
+ mgr->latchsets = (BtLatchSet *)(mgr->pages[0] + ((uid)LATCH_page << mgr->page_bits));
+ mgr->hashtable = (BtHashEntry *)(mgr->latchsets + mgr->pagezero->latchtotal);
+
+ return mgr;
+}
+
+// open BTree access method
+// based on buffer manager
+
+BtDb *bt_open (BtMgr *mgr, BtMgr *main)
+{
+BtDb *bt = malloc (sizeof(*bt));
+
+ memset (bt, 0, sizeof(*bt));
+ bt->tid = sys_gettid();
+ bt->main = main;
+ bt->mgr = mgr;
+ return bt;
+}
+
+// compare two keys, return > 0, = 0, or < 0
+// =0: keys are same
+// -1: key2 > key1
+// +1: key2 < key1
+// 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;
+}
+
+// place write, read, or parent lock on requested page_no.
+
+void bt_lockpage(BtLock mode, BtLatchSet *latch, pid_t tid, uint line)
+{
+ switch( mode ) {
+ case BtLockRead:
+ ReadLock (latch->readwr);
+ break;
+ case BtLockWrite:
+ WriteLock (latch->readwr, tid, line);
+ break;
+ case BtLockAccess:
+ ReadLock (latch->access);
+ break;
+ case BtLockDelete:
+ WriteLock (latch->access, tid, line);
+ break;
+ case BtLockParent:
+ WriteLock (latch->parent, tid, line);
+ break;
+ case BtLockLink:
+ WriteLock (latch->link, tid, line);
+ break;
+ }
+}
+
+// remove write, read, or parent lock on requested page
+
+void bt_unlockpage(BtLock mode, BtLatchSet *latch, uint line)
+{
+ switch( mode ) {
+ case BtLockRead:
+ ReadRelease (latch->readwr);
+ break;
+ case BtLockWrite:
+ WriteRelease (latch->readwr);
+ break;
+ case BtLockAccess:
+ ReadRelease (latch->access);
+ break;
+ case BtLockDelete:
+ WriteRelease (latch->access);
+ break;
+ case BtLockParent:
+ WriteRelease (latch->parent);
+ break;
+ case BtLockLink:
+ WriteRelease (latch->link);
+ break;
+ }
+}
+
+// allocate a new page
+// return with page latched, but unlocked.
+// contents is cleared for lvl > 0
+
+int bt_newpage(BtMgr *mgr, BtPageSet *set, BtPage contents)
+{
+uint page_size = mgr->page_size, blk;
+uid *freechain;
+uid page_no;
+
+ // lock allocation page
+
+ bt_mutexlock(mgr->pagezero->lock);
+
+ if( contents->lvl ) {
+ freechain = &mgr->pagezero->freechain;
+ mgr->pagezero->upperpages++;
+ } else {
+ freechain = &mgr->pagezero->leafchain;
+ mgr->pagezero->leafpages++;
+ page_size <<= mgr->leaf_xtra;
+ }
+
+ // use empty chain first
+ // else allocate new page
+
+ if( page_no = *freechain ) {
+ if( set->latch = bt_pinlatch (mgr, page_no) )
+ set->page = bt_mappage (mgr, set->latch);
+ else
+ return mgr->line = __LINE__, mgr->err = BTERR_struct;
+
+ *freechain = set->page->right;
+
+ // the page is currently nopromote and this
+ // will keep bt_promote out.
+
+ // contents will replace this bit
+ // and pin will keep bt_promote out
+
+ contents->nopromote = 0;
+
+ memcpy (set->page, contents, page_size);
+
+// if( msync (mgr->pagezero, mgr->page_size, MS_SYNC) < 0 )
+// fprintf(stderr, "msync error %d line %d\n", errno, __LINE__);
+
+ bt_releasemutex(mgr->pagezero->lock);
+ return 0;
+ }
+
+ // obtain next available page number
+ // suitable for leaf or higher level
+
+ page_no = mgr->pagezero->allocpage;
+ mgr->pagezero->allocpage += 1 << mgr->leaf_xtra;
+
+ // keep bt_promote out of this page
+
+ contents->nopromote = 1;
+
+ // unlock allocation latch and
+ // extend file into new page.
+
+// if( msync (mgr->pagezero, mgr->page_size, MS_SYNC) < 0 )
+// fprintf(stderr, "msync error %d line %d\n", errno, __LINE__);
+
+ if( bt_writepage (mgr, contents, page_no, !contents->lvl) )
+ fprintf(stderr, "Write %lld error %d\n", page_no + blk, errno);
+
+ // chain together unused non-leaf allocation
+
+ if( contents->lvl ) {
+ memset (contents, 0, mgr->page_size);
+
+ for( blk = 1; blk < 1 << mgr->leaf_xtra; blk++ ) {
+ if( bt_writepage (mgr, contents, page_no + blk, 0) )
+ fprintf(stderr, "Write %lld error %d\n", page_no + blk, errno);
+ contents->right = page_no + blk;
+ *freechain = page_no + blk;
+ }
+ }
+
+ bt_releasemutex(mgr->pagezero->lock);
+
+ if( set->latch = bt_pinlatch (mgr, page_no) )
+ set->page = bt_mappage (mgr, set->latch);
+ else
+ return mgr->err;
+
+ // now pin will keep bt_promote out
+
+ set->page->nopromote = 0;
+ return 0;
+}
+
+// find slot in page for given key at a given level
+
+int bt_findslot (BtPage page, unsigned char *key, uint len)
+{
+uint diff, higher = page->cnt, low = 1, slot;
+uint good = 0;
+
+ // make stopper key an infinite fence value
+
+ if( page->right )
+ higher++;
+ else
+ good++;
+
+ // low is the lowest candidate.
+ // loop ends when they meet
+
+ // higher is already
+ // tested as .ge. the passed key.
+
+ while( diff = higher - low ) {
+ slot = low + ( diff >> 1 );
+ if( keycmp (keyptr(page, slot), key, len) < 0 )
+ low = slot + 1;
+ else
+ higher = slot, good++;
+ }
+
+ // return zero if key is on right link page
+
+ return good ? higher : 0;
+}
+
+// find and load page at given level for given key
+// leave page rd or wr locked as requested
+
+int bt_loadpage (BtMgr *mgr, BtPageSet *set, unsigned char *key, uint len, uint lvl, BtLock lock, pid_t tid)
+{
+uid page_no = ROOT_page, prevpage_no = 0;
+uint drill = 0xff, slot;
+uint mode, prevmode;
+BtPageSet prev[1];
+BtVal *val;
+BtKey *ptr;
+
+ // start at root of btree and drill down
+
+ do {
+ if( set->latch = bt_pinlatch (mgr, page_no) )
+ set->page = bt_mappage (mgr, set->latch);
+ else
+ return 0;
+
+ if( page_no > ROOT_page )
+ bt_lockpage(BtLockAccess, set->latch, tid, __LINE__);
+
+ // release & unpin parent or left sibling page
+
+ if( prevpage_no ) {
+ bt_unlockpage(prevmode, prev->latch, __LINE__);
+ bt_unpinlatch (prev->latch);
+ prevpage_no = 0;
+ }
+
+ // obtain mode lock using lock coupling through AccessLock
+ // determine lock mode of drill level
+
+ mode = (drill == lvl) ? lock : BtLockRead;
+ bt_lockpage(mode, set->latch, tid, __LINE__);
+
+ // grab our fence key
+
+ ptr=fenceptr(set->page);
+
+ if( set->page->free )
+ return mgr->err = BTERR_struct, mgr->line = __LINE__, 0;
+
+ if( page_no > ROOT_page )
+ bt_unlockpage(BtLockAccess, set->latch, __LINE__);
+
+ // re-read and re-lock root after determining actual level of root
+
+ if( set->page->lvl != drill) {
+ if( set->latch->page_no != ROOT_page )
+ return mgr->err = BTERR_struct, mgr->line = __LINE__, 0;
+
+ drill = set->page->lvl;
+
+ if( lock != BtLockRead && drill == lvl ) {
+ bt_unlockpage(mode, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+ continue;
+ }
+ }
+
+ prevpage_no = set->latch->page_no;
+ prevmode = mode;
+ *prev = *set;
+
+ // if requested key is beyond our fence,
+ // slide to the right
+
+ if( keycmp (ptr, key, len) < 0 )
+ if( page_no = set->page->right )
+ continue;
+
+ // if page is part of a delete operation,
+ // slide to the left;
+
+ if( set->page->kill ) {
+ bt_lockpage(BtLockLink, set->latch, tid, __LINE__);
+ page_no = set->page->left;
+ bt_unlockpage(BtLockLink, set->latch, __LINE__);
+ continue;
+ }
+
+ // find key on page at this level
+ // and descend to requested level
+
+ 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;
+ else
+ return mgr->err = BTERR_struct, mgr->line = __LINE__, 0;
+
+ val = valptr(set->page, slot);
+
+ if( val->len == BtId )
+ page_no = bt_getid(val->value);
+ else
+ return mgr->line = __LINE__, mgr->err = BTERR_struct, 0;
+
+ drill--;
+ continue;
+ }
+
+ // slide right into next page
+
+ page_no = set->page->right;
+
+ } while( page_no );
+
+ // return error on end of right chain
+
+ mgr->line = __LINE__, mgr->err = BTERR_struct;
+ return 0; // return error
+}
+
+// return page to free list
+// page must be delete, link & write locked
+// and have no keys pointing to it.
+
+void bt_freepage (BtMgr *mgr, BtPageSet *set)
+{
+uid *freechain;
+
+ // lock allocation page
+
+ bt_mutexlock (mgr->pagezero->lock);
+
+ if( set->page->lvl ) {
+ freechain = &mgr->pagezero->freechain;
+ mgr->pagezero->upperpages--;
+ } else {
+ freechain = &mgr->pagezero->leafchain;
+ mgr->pagezero->leafpages--;
+ }
+
+ // store chain link
+
+ set->page->right = *freechain;
+ *freechain = set->latch->page_no;
+ set->page->free = 1;
+
+// if( msync (mgr->pagezero, mgr->page_size, MS_SYNC) < 0 )
+// fprintf(stderr, "msync error %d line %d\n", errno, __LINE__);
+
+ // unlock released page
+ // and unlock allocation page
+
+ bt_unlockpage (BtLockDelete, set->latch, __LINE__);
+ bt_unlockpage (BtLockWrite, set->latch, __LINE__);
+ bt_unlockpage (BtLockLink, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+ bt_releasemutex (mgr->pagezero->lock);
+}
+
+// a fence key was deleted from an interiour level page
+// push new fence value upwards
+
+BTERR bt_fixfence (BtMgr *mgr, BtPageSet *set, uint lvl)
+{
+unsigned char leftkey[BT_keyarray], rightkey[BT_keyarray];
+unsigned char value[BtId];
+BtKey* ptr;
+uint idx;
+
+ // remove the old fence value
+
+ ptr = fenceptr(set->page);
+ memcpy (rightkey, ptr, ptr->len + sizeof(BtKey));
+ memset (slotptr(set->page, set->page->cnt--), 0, sizeof(BtSlot));
+ set->page->fence = slotptr(set->page, set->page->cnt)->off;
+
+ // cache new fence value
+
+ ptr = fenceptr(set->page);
+ memcpy (leftkey, ptr, ptr->len + sizeof(BtKey));
+
+ bt_lockpage (BtLockParent, set->latch, 0, __LINE__);
+ bt_unlockpage (BtLockWrite, set->latch, __LINE__);
+
+ // insert new (now smaller) fence key
+
+ bt_putid (value, set->latch->page_no);
+ ptr = (BtKey*)leftkey;
+
+ if( bt_insertkey (mgr, ptr->key, ptr->len, lvl+1, value, BtId, Unique) )
+ return mgr->err;
+
+ // now delete old fence key
+
+ ptr = (BtKey*)rightkey;
+
+ if( bt_deletekey (mgr, ptr->key, ptr->len, lvl+1) )
+ return mgr->err;
+
+ bt_unlockpage (BtLockParent, set->latch, __LINE__);
+ bt_unpinlatch(set->latch);
+ return 0;
+}
+
+// root has a single child
+// collapse a level from the tree
+
+BTERR bt_collapseroot (BtMgr *mgr, BtPageSet *root)
+{
+BtPageSet child[1];
+uid page_no;
+BtVal *val;
+uint idx;
+
+ // find the child entry and promote as new root contents
+
+ do {
+ for( idx = 0; idx++ < root->page->cnt; )
+ if( !slotptr(root->page, idx)->dead )
+ break;
+
+ val = valptr(root->page, idx);
+
+ if( val->len == BtId )
+ page_no = bt_getid (valptr(root->page, idx)->value);
+ else
+ return mgr->line = __LINE__, mgr->err = BTERR_struct;
+
+ if( child->latch = bt_pinlatch (mgr, page_no) )
+ child->page = bt_mappage (mgr, child->latch);
+ else
+ return mgr->err;
+
+ bt_lockpage (BtLockDelete, child->latch, 0, __LINE__);
+ bt_lockpage (BtLockWrite, child->latch, 0, __LINE__);
+
+ memcpy (root->page, child->page, mgr->page_size);
+ bt_freepage (mgr, child);
+
+ } while( root->page->lvl > 1 && root->page->act == 1 );
+
+ bt_unlockpage (BtLockWrite, root->latch, __LINE__);
+ bt_unpinlatch (root->latch);
+ return 0;
+}
+
+// delete a page and manage key
+// call with page writelocked
+
+// returns with page unpinned
+// from the page pool.
+
+BTERR bt_deletepage (BtMgr *mgr, BtPageSet *set, uint lvl)
+{
+unsigned char higherfence[BT_keyarray], lowerfence[BT_keyarray];
+uint page_size = mgr->page_size, kill;
+BtPageSet right[1], temp[1];
+unsigned char value[BtId];
+uid page_no, right2;
+BtKey *ptr;
+
+ if( !lvl )
+ page_size <<= mgr->leaf_xtra;
+
+ // cache original copy of original fence key
+ // that is going to be deleted.
+
+ ptr = fenceptr(set->page);
+ memcpy (lowerfence, ptr, ptr->len + sizeof(BtKey));
+
+ // pin and lock our right page
+
+ page_no = set->page->right;
+
+ if( right->latch = bt_pinlatch (mgr, page_no) )
+ right->page = bt_mappage (mgr, right->latch);
+ else
+ return 0;
+
+ bt_lockpage (BtLockWrite, right->latch, 0, __LINE__);
+
+ if( right->page->kill || set->page->kill )
+ return mgr->line = __LINE__, mgr->err = BTERR_struct;
+
+ // pull contents of right sibling over our empty page
+ // preserving our left page number, and its right page number.
+
+ bt_lockpage (BtLockLink, set->latch, 0, __LINE__);
+ page_no = set->page->left;
+ memcpy (set->page, right->page, page_size);
+ set->page->left = page_no;
+ bt_unlockpage (BtLockLink, set->latch, __LINE__);
+
+ // fix left link from far right page
+
+ if( right2 = set->page->right ) {
+ if( temp->latch = bt_pinlatch (mgr, right2) )
+ temp->page = bt_mappage (mgr, temp->latch);
+ else
+ return 0;
+
+ bt_lockpage (BtLockAccess, temp->latch, 0, __LINE__);
+ bt_lockpage(BtLockLink, temp->latch, 0, __LINE__);
+ temp->page->left = set->latch->page_no;
+ bt_unlockpage(BtLockLink, temp->latch, __LINE__);
+ bt_unlockpage(BtLockAccess, temp->latch, __LINE__);
+ bt_unpinlatch (temp->latch);
+ } else if( !lvl ) { // our page is now rightmost leaf
+ bt_mutexlock (mgr->pagezero->lock);
+ mgr->pagezero->rightleaf = set->latch->page_no;
+ bt_releasemutex(mgr->pagezero->lock);
+ }
+
+ ptr = fenceptr(set->page);
+ memcpy (higherfence, ptr, ptr->len + sizeof(BtKey));
+
+ // mark right page as being deleted and release lock
+ // keep lock on parent modification.
+
+ right->page->kill = 1;
+ bt_lockpage (BtLockParent, right->latch, 0, __LINE__);
+ bt_unlockpage (BtLockWrite, right->latch, __LINE__);
+
+ bt_lockpage (BtLockParent, set->latch, 0, __LINE__);
+ bt_unlockpage (BtLockWrite, set->latch, __LINE__);
+
+ // redirect the new higher key directly to our new node
+
+ ptr = (BtKey *)higherfence;
+ bt_putid (value, set->latch->page_no);
+
+ if( bt_insertkey (mgr, ptr->key, ptr->len, lvl+1, value, BtId, Update) )
+ return mgr->err;
+
+ // delete our original fence key in parent
+
+ ptr = (BtKey *)lowerfence;
+
+ if( bt_deletekey (mgr, ptr->key, ptr->len, lvl+1) )
+ return mgr->err;
+
+ // wait for all access to drain away with delete lock,
+ // then obtain write lock to right node and free it.
+
+ bt_lockpage (BtLockDelete, right->latch, 0, __LINE__);
+ bt_lockpage (BtLockWrite, right->latch, 0, __LINE__);
+ bt_lockpage (BtLockLink, right->latch, 0, __LINE__);
+ bt_unlockpage (BtLockParent, right->latch, __LINE__);
+ bt_freepage (mgr, right);
+
+ // release parent lock to our node
+
+ bt_unlockpage (BtLockParent, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+ return 0;
+}
+
+// find and delete key on page by marking delete flag bit
+// if page becomes empty, delete it from the btree
+
+BTERR bt_deletekey (BtMgr *mgr, unsigned char *key, uint len, uint lvl)
+{
+uint slot, idx, found, fence;
+BtPageSet set[1];
+BtSlot *node;
+BtKey *ptr;
+BtVal *val;
+
+ if( slot = bt_loadpage (mgr, set, key, len, lvl, BtLockWrite, 0) ) {
+ node = slotptr(set->page, slot);
+ ptr = keyptr(set->page, slot);
+ } else
+ return mgr->err;
+
+ // if librarian slot, advance to real slot
+
+ if( node->type == Librarian ) {
+ ptr = keyptr(set->page, ++slot);
+ node = slotptr(set->page, slot);
+ }
+
+ fence = slot == set->page->cnt;
+
+ // delete the key, ignore request if already dead
+
+ if( found = !keycmp (ptr, key, len) )
+ if( found = node->dead == 0 ) {
+ val = valptr(set->page,slot);
+ set->page->garbage += ptr->len + val->len + sizeof(BtKey) + sizeof(BtVal);
+ set->page->act--;
+ node->dead = 1;
+
+ // collapse empty slots beneath the fence
+ // on interiour nodes
+
+ if( lvl )
+ 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( !found )
+ return 0;
+
+ // did we delete a fence key in an upper level?
+
+ if( lvl && set->page->act && fence )
+ return bt_fixfence (mgr, set, lvl);
+
+ // do we need to collapse root?
+
+ if( lvl > 1 && set->latch->page_no == ROOT_page && set->page->act == 1 )
+ return bt_collapseroot (mgr, set);
+
+ // delete empty page
+
+ if( !set->page->act )
+ return bt_deletepage (mgr, set, set->page->lvl);
+
+ bt_unlockpage(BtLockWrite, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+ return 0;
+}
+
+// check page for space available,
+// clean if necessary and return
+// 0 - page needs splitting
+// >0 new slot value
+
+uint bt_cleanpage(BtMgr *mgr, BtPageSet *set, uint keylen, uint slot, uint vallen)
+{
+uint page_size = mgr->page_size;
+BtPage page = set->page, frame;
+uint cnt = 0, idx = 0;
+uint max = page->cnt;
+uint newslot = max;
+BtKey *key;
+BtVal *val;
+
+ if( !set->page->lvl )
+ page_size <<= mgr->leaf_xtra;
+
+ if( page->min >= (max+2) * sizeof(BtSlot) + sizeof(*page) + keylen + sizeof(BtKey) + vallen + sizeof(BtVal))
+ return slot;
+
+ // skip cleanup and proceed to split
+ // if there's not enough garbage
+ // to bother with.
+
+ if( page->garbage < page_size / 5 )
+ return 0;
+
+ frame = malloc (page_size);
+ memcpy (frame, page, page_size);
+
+ // skip page info and set rest of page to zero
+
+ memset (page+1, 0, page_size - sizeof(*page));
+
+ page->min = page_size;
+ page->garbage = 0;
+ page->act = 0;
+
+ // clean up page first by
+ // removing dead keys
+
+ while( cnt++ < max ) {
+ if( cnt == slot )
+ newslot = idx + 2;
+
+ if( cnt < max || frame->lvl )
+ if( slotptr(frame,cnt)->dead )
+ continue;
+
+ // copy the value across
+
+ val = valptr(frame, cnt);
+ page->min -= val->len + sizeof(BtVal);
+ memcpy ((unsigned char *)page + page->min, val, val->len + sizeof(BtVal));
+
+ // copy the key across
+
+ key = keyptr(frame, cnt);
+ page->min -= key->len + sizeof(BtKey);
+ memcpy ((unsigned char *)page + page->min, key, key->len + sizeof(BtKey));
+
+ // make a librarian slot
+
+ slotptr(page, ++idx)->off = page->min;
+ slotptr(page, idx)->type = Librarian;
+ slotptr(page, idx)->dead = 1;
+
+ // set up the slot
+
+ slotptr(page, ++idx)->off = page->min;
+ slotptr(page, idx)->type = slotptr(frame, cnt)->type;
+
+ if( !(slotptr(page, idx)->dead = slotptr(frame, cnt)->dead) )
+ page->act++;
+ }
+
+ page->fence = page->min;
+ page->cnt = idx;
+ free (frame);
+
+ // see if page has enough space now, or does it need splitting?
+
+ if( page->min >= (idx+2) * sizeof(BtSlot) + sizeof(*page) + keylen + sizeof(BtKey) + vallen + sizeof(BtVal) )
+ return newslot;
+
+ return 0;
+}
+
+// split the root and raise the height of the btree
+
+BTERR bt_splitroot(BtMgr *mgr, BtPageSet *root, BtLatchSet *right)
+{
+unsigned char leftkey[BT_keyarray];
+uint nxt = mgr->page_size;
+unsigned char value[BtId];
+BtPage frame, page;
+BtPageSet left[1];
+uid left_page_no;
+BtKey *ptr;
+BtVal *val;
+
+ frame = malloc (mgr->page_size);
+ memcpy (frame, root->page, mgr->page_size);
+
+ // save left page fence key for new root
+
+ ptr = fenceptr(root->page);
+ memcpy (leftkey, ptr, ptr->len + sizeof(BtKey));
+
+ // Obtain an empty page to use, and copy the current
+ // root contents into it, e.g. lower keys
+
+ if( bt_newpage(mgr, left, frame) )
+ return mgr->err;
+
+ left_page_no = left->latch->page_no;
+ bt_unpinlatch (left->latch);
+ free (frame);
+
+ // left link the pages together
+
+ page = bt_mappage (mgr, right);
+ page->left = left_page_no;
+
+ // preserve the page info at the bottom
+ // of higher keys and set rest to zero
+
+ memset(root->page+1, 0, mgr->page_size - sizeof(*root->page));
+
+ // insert stopper key at top of newroot page
+ // and increase the root height
+
+ nxt -= BtId + sizeof(BtVal);
+ bt_putid (value, right->page_no);
+ val = (BtVal *)((unsigned char *)root->page + nxt);
+ memcpy (val->value, value, BtId);
+ val->len = BtId;
+
+ nxt -= 2 + sizeof(BtKey);
+ page->fence = nxt;
+
+ slotptr(root->page, 2)->off = nxt;
+ ptr = (BtKey *)((unsigned char *)root->page + nxt);
+ ptr->len = 2;
+ ptr->key[0] = 0xff;
+ ptr->key[1] = 0xff;
+
+ // insert lower keys page fence key on newroot page as first key
+
+ nxt -= BtId + sizeof(BtVal);
+ bt_putid (value, left_page_no);
+ val = (BtVal *)((unsigned char *)root->page + nxt);
+ memcpy (val->value, value, BtId);
+ val->len = BtId;
+
+ ptr = (BtKey *)leftkey;
+ nxt -= ptr->len + sizeof(BtKey);
+ slotptr(root->page, 1)->off = nxt;
+ memcpy ((unsigned char *)root->page + nxt, leftkey, ptr->len + sizeof(BtKey));
+
+ root->page->right = 0;
+ root->page->min = nxt; // reset lowest used offset and key count
+ root->page->cnt = 2;
+ root->page->act = 2;
+ root->page->lvl++;
+
+ // release and unpin root pages
+
+ bt_unlockpage(BtLockWrite, root->latch, __LINE__);
+ bt_unpinlatch (root->latch);
+
+ bt_unpinlatch (right);
+ return 0;
+}
+
+// split already locked full node
+// leave it locked.
+// return pool entry for new right
+// page, pinned & unlocked
+
+uint bt_splitpage (BtMgr *mgr, BtPageSet *set, uint linkleft)
+{
+uint page_size = mgr->page_size;
+BtPageSet right[1], temp[1];
+uint cnt = 0, idx = 0, max;
+uint lvl = set->page->lvl;
+BtPage frame;
+BtKey *key;
+BtVal *val;
+uid right2;
+uint entry;
+uint prev;
+
+ if( !set->page->lvl )
+ page_size <<= mgr->leaf_xtra;
+
+ // split higher half of keys to frame
+
+ frame = malloc (page_size);
+ memset (frame, 0, page_size);
+ frame->min = page_size;
+ max = set->page->cnt;
+ cnt = max / 2;
+ idx = 0;
+
+ while( cnt++ < max ) {
+ if( cnt < max || set->page->lvl )
+ if( slotptr(set->page, cnt)->dead )
+ continue;
+
+ val = valptr(set->page, cnt);
+ frame->min -= val->len + sizeof(BtVal);
+ memcpy ((unsigned char *)frame + frame->min, val, val->len + sizeof(BtVal));
+
+ key = keyptr(set->page, cnt);
+ frame->min -= key->len + sizeof(BtKey);
+ memcpy ((unsigned char *)frame + frame->min, key, key->len + sizeof(BtKey));
+
+ // add librarian slot
+
+ slotptr(frame, ++idx)->off = frame->min;
+ slotptr(frame, idx)->type = Librarian;
+ slotptr(frame, idx)->dead = 1;
+
+ // add actual slot
+
+ slotptr(frame, ++idx)->off = frame->min;
+ slotptr(frame, idx)->type = slotptr(set->page, cnt)->type;
+
+ if( !(slotptr(frame, idx)->dead = slotptr(set->page, cnt)->dead) )
+ frame->act++;
+ }
+
+ frame->fence = frame->min;
+ frame->cnt = idx;
+ frame->lvl = lvl;
+
+ // link right node
+
+ if( set->latch->page_no > ROOT_page ) {
+ right2 = set->page->right;
+ frame->right = right2;
+
+ if( linkleft )
+ frame->left = set->latch->page_no;
+ }
+
+ // get new free page and write higher keys to it.
+
+ if( bt_newpage(mgr, right, frame) )
+ return 0;
+
+ // link far right's left pointer to new page
+
+ if( linkleft && set->latch->page_no > ROOT_page )
+ if( right2 ) {
+ if( temp->latch = bt_pinlatch (mgr, right2) )
+ temp->page = bt_mappage (mgr, temp->latch);
+ else
+ return 0;
+
+ bt_lockpage(BtLockLink, temp->latch, 0, __LINE__);
+ temp->page->left = right->latch->page_no;
+ bt_unlockpage(BtLockLink, temp->latch, __LINE__);
+ bt_unpinlatch (temp->latch);
+ } else if( !lvl ) { // page is rightmost leaf
+ bt_mutexlock (mgr->pagezero->lock);
+ mgr->pagezero->rightleaf = right->latch->page_no;
+ bt_releasemutex(mgr->pagezero->lock);
+ }
+
+ // process lower keys
+
+ memcpy (frame, set->page, page_size);
+ memset (set->page+1, 0, page_size - sizeof(*set->page));
+
+ set->page->min = page_size;
+ set->page->garbage = 0;
+ set->page->act = 0;
+ max /= 2;
+ cnt = 0;
+ idx = 0;
+
+ // assemble page of smaller keys
+
+ while( cnt++ < max ) {
+ if( slotptr(frame, cnt)->dead )
+ continue;
+ val = valptr(frame, cnt);
+ set->page->min -= val->len + sizeof(BtVal);
+ memcpy ((unsigned char *)set->page + set->page->min, val, val->len + sizeof(BtVal));
+
+ key = keyptr(frame, cnt);
+ set->page->min -= key->len + sizeof(BtKey);
+ memcpy ((unsigned char *)set->page + set->page->min, key, key->len + sizeof(BtKey));
+
+ // add librarian slot
+
+ slotptr(set->page, ++idx)->off = set->page->min;
+ slotptr(set->page, idx)->type = Librarian;
+ slotptr(set->page, idx)->dead = 1;
+
+ // add actual slot
+
+ slotptr(set->page, ++idx)->off = set->page->min;
+ slotptr(set->page, idx)->type = slotptr(frame, cnt)->type;
+ set->page->act++;
+ }
+
+ set->page->right = right->latch->page_no;
+ set->page->fence = set->page->min;
+ set->page->cnt = idx;
+ free(frame);
+
+ entry = right->latch - mgr->latchsets;
+ return entry;
+}
+
+// fix keys for newly split page
+// call with both pages pinned & locked
+// return unlocked and unpinned
+
+BTERR bt_splitkeys (BtMgr *mgr, BtPageSet *set, BtLatchSet *right)
+{
+unsigned char leftkey[BT_keyarray], rightkey[BT_keyarray];
+unsigned char value[BtId];
+uint lvl = set->page->lvl;
+BtPageSet temp[1];
+BtPage page;
+BtKey *ptr;
+uid right2;
+
+ // if current page is the root page, split it
+
+ if( set->latch->page_no == ROOT_page )
+ return bt_splitroot (mgr, set, right);
+
+ ptr = fenceptr(set->page);
+ memcpy (leftkey, ptr, ptr->len + sizeof(BtKey));
+
+ page = bt_mappage (mgr, right);
+
+ ptr = fenceptr(page);
+ memcpy (rightkey, ptr, ptr->len + sizeof(BtKey));
+
+ // splice in far right page's left page_no
+
+ if( right2 = page->right ) {
+ if( temp->latch = bt_pinlatch (mgr, right2) )
+ temp->page = bt_mappage (mgr, temp->latch);
+ else
+ return 0;
+
+ bt_lockpage(BtLockLink, temp->latch, 0, __LINE__);
+ temp->page->left = right->page_no;
+ bt_unlockpage(BtLockLink, temp->latch, __LINE__);
+ bt_unpinlatch (temp->latch);
+ } else if( !lvl ) { // right page is far right page
+ bt_mutexlock (mgr->pagezero->lock);
+ mgr->pagezero->rightleaf = right->page_no;
+ bt_releasemutex(mgr->pagezero->lock);
+ }
+ // insert new fences in their parent pages
+
+ bt_lockpage (BtLockParent, right, 0, __LINE__);
+
+ bt_lockpage (BtLockParent, set->latch, 0, __LINE__);
+ bt_unlockpage (BtLockWrite, set->latch, __LINE__);
+
+ // insert new fence for reformulated left block of smaller keys
+
+ bt_putid (value, set->latch->page_no);
+ ptr = (BtKey *)leftkey;
+
+ if( bt_insertkey (mgr, ptr->key, ptr->len, lvl+1, value, BtId, Unique) )
+ return mgr->err;
+
+ // switch fence for right block of larger keys to new right page
+
+ bt_putid (value, right->page_no);
+ ptr = (BtKey *)rightkey;
+
+ if( bt_insertkey (mgr, ptr->key, ptr->len, lvl+1, value, BtId, Unique) )
+ return mgr->err;
+
+ bt_unlockpage (BtLockParent, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+
+ bt_unlockpage (BtLockParent, right, __LINE__);
+ bt_unpinlatch (right);
+ return 0;
+}
+
+// install new key and value onto page
+// page must already be checked for
+// adequate space
+
+BTERR bt_insertslot (BtMgr *mgr, BtPageSet *set, uint slot, unsigned char *key,uint keylen, unsigned char *value, uint vallen, uint type)
+{
+uint idx, librarian;
+BtSlot *node;
+BtKey *ptr;
+BtVal *val;
+int rate;
+
+ // if previous slot is a librarian slot, use it
+
+ if( slot > 1 )
+ if( slotptr(set->page, slot-1)->type == Librarian )
+ slot--;
+
+ // copy value onto page
+
+ set->page->min -= vallen + sizeof(BtVal);
+ val = (BtVal*)((unsigned char *)set->page + set->page->min);
+ memcpy (val->value, value, vallen);
+ val->len = vallen;
+
+ // copy key onto page
+
+ set->page->min -= keylen + sizeof(BtKey);
+ ptr = (BtKey*)((unsigned char *)set->page + set->page->min);
+ memcpy (ptr->key, key, keylen);
+ ptr->len = keylen;
+
+ // find first empty slot at or above our insert slot
+
+ for( idx = slot; idx < set->page->cnt; idx++ )
+ if( slotptr(set->page, idx)->dead )
+ break;
+
+ // now insert key into array before slot.
+
+ // if we're going all the way to the top,
+ // add as many librarian slots as
+ // makes sense.
+
+ if( idx == set->page->cnt ) {
+ int avail = 4 * set->page->min / 5 - sizeof(*set->page) - ++set->page->cnt * sizeof(BtSlot);
+
+ librarian = ++idx - slot;
+ avail /= sizeof(BtSlot);
+
+ if( avail < 0 )
+ avail = 0;
+
+ if( librarian > avail )
+ librarian = avail;
+
+ if( librarian ) {
+ rate = (idx - slot) / librarian;
+ set->page->cnt += librarian;
+ idx += librarian;
+ } else
+ rate = 0;
+ } else
+ librarian = 0, rate = 0;
+
+ // transfer slots and add librarian slots
+
+ while( idx > slot ) {
+ *slotptr(set->page, idx) = *slotptr(set->page, idx-librarian-1);
+
+ // add librarian slot per rate
+
+ if( librarian )
+ if( (idx - slot)/2 <= librarian * rate ) {
+ node = slotptr(set->page, --idx);
+ node->off = node[1].off;
+ node->type = Librarian;
+ node->dead = 1;
+ librarian--;
+ }
+
+ --idx;
+ }
+
+ set->page->act++;
+
+ // fill in new slot
+
+ node = slotptr(set->page, slot);
+ node->off = set->page->min;
+ node->type = type;
+ node->dead = 0;
+ return 0;
+}
+
+// Insert new key into the btree at given level.
+// either add a new key or update/add an existing one
+
+BTERR bt_insertkey (BtMgr *mgr, unsigned char *key, uint keylen, uint lvl, void *value, uint vallen, BtSlotType type)
+{
+uint slot, idx, len, entry;
+BtPageSet set[1];
+BtSlot *node;
+BtKey *ptr;
+BtVal *val;
+
+ while( 1 ) { // find the page and slot for the current key
+ if( slot = bt_loadpage (mgr, set, key, keylen, lvl, BtLockWrite, 0) ) {
+ node = slotptr(set->page, slot);
+ ptr = keyptr(set->page, slot);
+ } else
+ return mgr->err;
+
+ // if librarian slot == found slot, advance to real slot
+
+ if( node->type == Librarian ) {
+ node = slotptr(set->page, ++slot);
+ ptr = keyptr(set->page, slot);
+ }
+
+ // if inserting a duplicate key or unique
+ // key that doesn't exist on the page,
+ // check for adequate space on the page
+ // and insert the new key before slot.
+
+ switch( type ) {
+ case Unique:
+ case Duplicate:
+ if( !keycmp (ptr, key, keylen) )
+ break;
+
+ if( slot = bt_cleanpage (mgr, set, keylen, slot, vallen) )
+ if( bt_insertslot (mgr, set, slot, key, keylen, value, vallen, type) )
+ return mgr->err;
+ else
+ goto insxit;
+
+ if( entry = bt_splitpage (mgr, set, 1) )
+ if( !bt_splitkeys (mgr, set, entry + mgr->latchsets) )
+ continue;
+
+ return mgr->err;
+
+ case Update:
+ if( keycmp (ptr, key, keylen) )
+ goto insxit;
+
+ break;
+ }
+
+ // if key already exists, update value and return
+
+ val = valptr(set->page, slot);
+
+ if( val->len >= vallen ) {
+ if( node->dead )
+ set->page->act++;
+ node->type = type;
+ node->dead = 0;
+
+ set->page->garbage += val->len - vallen;
+ val->len = vallen;
+ memcpy (val->value, value, vallen);
+ goto insxit;
+ }
+
+ // new update value doesn't fit in existing value area
+ // make sure page has room
+
+ if( !node->dead )
+ set->page->garbage += val->len + ptr->len + sizeof(BtKey) + sizeof(BtVal);
+ else
+ set->page->act++;
+
+ node->type = type;
+ node->dead = 0;
+
+ if( slot = bt_cleanpage (mgr, set, keylen, slot, vallen) )
+ break;
+
+ if( entry = bt_splitpage (mgr, set, 1) )
+ if( !bt_splitkeys (mgr, set, entry + mgr->latchsets) )
+ continue;
+
+ return mgr->err;
+ }
+
+ // copy key and value onto page and update slot
+
+ set->page->min -= vallen + sizeof(BtVal);
+ val = (BtVal*)((unsigned char *)set->page + set->page->min);
+ memcpy (val->value, value, vallen);
+ val->len = vallen;
+
+ set->page->min -= keylen + sizeof(BtKey);
+ ptr = (BtKey*)((unsigned char *)set->page + set->page->min);
+ memcpy (ptr->key, key, keylen);
+ ptr->len = keylen;
+
+ slotptr(set->page,slot)->off = set->page->min;
+
+insxit:
+ bt_unlockpage(BtLockWrite, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+ return 0;
+}
+
+// determine actual page where key is located
+// return slot number
+
+uint bt_atomicpage (BtMgr *mgr, BtPage source, AtomicTxn *locks, uint idx, BtPageSet *set)
+{
+BtKey *key = keyptr(source,locks[idx].src), *ptr;
+uint slot = locks[idx].slot;
+uint entry;
+
+ if( locks[idx].reuse )
+ entry = locks[idx-1].entry;
+ else
+ entry = locks[idx].entry;
+
+ if( slot ) {
+ set->latch = mgr->latchsets + entry;
+ set->page = bt_mappage (mgr, set->latch);
+ return slot;
+ }
+
+ // find where our key is located
+ // on current page or pages split on
+ // same page txn operations.
+
+ do {
+ set->latch = mgr->latchsets + entry;
+ set->page = bt_mappage (mgr, set->latch);
+
+ if( slot = bt_findslot(set->page, key->key, key->len) ) {
+ if( slotptr(set->page, slot)->type == Librarian )
+ slot++;
+ if( locks[idx].reuse )
+ locks[idx].entry = entry;
+ return slot;
+ }
+ } while( entry = set->latch->split );
+
+ mgr->line = __LINE__, mgr->err = BTERR_atomic;
+ return 0;
+}
+
+BTERR bt_atomicinsert (BtMgr *mgr, BtPage source, AtomicTxn *locks, uint idx)
+{
+BtKey *key = keyptr(source, locks[idx].src);
+BtVal *val = valptr(source, locks[idx].src);
+BtLatchSet *latch;
+BtPageSet set[1];
+uint entry, slot;
+
+ while( slot = bt_atomicpage (mgr, source, locks, idx, set) ) {
+ if( slot = bt_cleanpage(mgr, set, key->len, slot, val->len) ) {
+ if( bt_insertslot (mgr, set, slot, key->key, key->len, val->value, val->len, slotptr(source,locks[idx].src)->type) )
+ return mgr->err;
+
+ return 0;
+ }
+
+ // split page
+
+ if( entry = bt_splitpage (mgr, set, 0) )
+ latch = mgr->latchsets + entry;
+ else
+ return mgr->err;
+
+ // splice right page into split chain
+ // and WriteLock it
+
+ bt_lockpage(BtLockWrite, latch, 0, __LINE__);
+ latch->split = set->latch->split;
+ set->latch->split = entry;
+
+ // clear slot number for atomic page
+
+ locks[idx].slot = 0;
+ }
+
+ return mgr->line = __LINE__, mgr->err = BTERR_atomic;
+}
+
+// perform delete from smaller btree
+// insert a delete slot if not found there
+
+BTERR bt_atomicdelete (BtMgr *mgr, BtPage source, AtomicTxn *locks, uint idx)
+{
+BtKey *key = keyptr(source, locks[idx].src);
+BtLatchSet *latch;
+uint slot, entry;
+BtPageSet set[1];
+BtSlot *node;
+BtKey *ptr;
+BtVal *val;
+
+ while( slot = bt_atomicpage (mgr, source, locks, idx, set) ) {
+ node = slotptr(set->page, slot);
+ ptr = keyptr(set->page, slot);
+ val = valptr(set->page, slot);
+
+ // if slot is not found on cache btree, insert a delete slot
+ // otherwise ignore the request.
+
+ if( keycmp (ptr, key->key, key->len) )
+ if( !mgr->type )
+ if( slot = bt_cleanpage(mgr, set, key->len, slot, 0) )
+ return bt_insertslot (mgr, set, slot, key->key, key->len, NULL, 0, Delete);
+ else { // split page before inserting Delete slot
+ if( entry = bt_splitpage (mgr, set, 0) )
+ latch = mgr->latchsets + entry;
+ else
+ return mgr->err;
+
+ // splice right page into split chain
+ // and WriteLock it
+
+ bt_lockpage(BtLockWrite, latch, 0, __LINE__);
+ latch->split = set->latch->split;
+ set->latch->split = entry;
+
+ // clear slot number for atomic page
+
+ locks[idx].slot = 0;
+ continue;
+ }
+ else
+ return 0;
+
+ // if node is already dead,
+ // ignore the request.
+
+ if( node->type == Delete || node->dead )
+ return 0;
+
+ // if main LSM btree, delete the slot
+ // else change to delete type.
+
+ if( mgr->type ) {
+ set->page->act--;
+ node->dead = 1;
+ } else
+ node->type = Delete;
+
+ __sync_fetch_and_add(&mgr->found, 1);
+ return 0;
+ }
+
+ return mgr->line = __LINE__, mgr->err = BTERR_struct;
+}
+
+// release master's splits from right to left
+
+void bt_atomicrelease (BtMgr *mgr, uint entry)
+{
+BtLatchSet *latch = mgr->latchsets + entry;
+
+ if( latch->split )
+ bt_atomicrelease (mgr, latch->split);
+
+ latch->split = 0;
+ bt_unlockpage(BtLockWrite, latch, __LINE__);
+ bt_unpinlatch(latch);
+}
+
+int qsortcmp (BtSlot *slot1, BtSlot *slot2, BtPage page)
+{
+BtKey *key1 = (BtKey *)((char *)page + slot1->off);
+BtKey *key2 = (BtKey *)((char *)page + slot2->off);
+
+ return keycmp (key1, key2->key, key2->len);
+}
+// atomic modification of a batch of keys.
+
+BTERR bt_atomictxn (BtDb *bt, BtPage source)
+{
+uint src, idx, slot, samepage, entry, que = 0;
+BtKey *key, *ptr, *key2;
+int result = 0;
+BtSlot temp[1];
+int type;
+
+ // stable sort the list of keys into order to
+ // prevent deadlocks between threads.
+/*
+ for( src = 1; src++ < source->cnt; ) {
+ *temp = *slotptr(source,src);
+ key = keyptr (source,src);
+
+ for( idx = src; --idx; ) {
+ key2 = keyptr (source,idx);
+ if( keycmp (key, key2->key, key2->len) < 0 ) {
+ *slotptr(source,idx+1) = *slotptr(source,idx);
+ *slotptr(source,idx) = *temp;
+ } else
+ break;
+ }
+ }
+*/
+ qsort_r (slotptr(source,1), source->cnt, sizeof(BtSlot), (__compar_d_fn_t)qsortcmp, source);
+
+ // perform the individual actions in the transaction
+
+ if( bt_atomicexec (bt->mgr, source, source->cnt, bt->tid) )
+ return bt->mgr->err;
+
+ // if number of active pages
+ // is greater than the buffer pool
+ // promote page into larger btree
+
+ if( bt->main )
+ if( bt->mgr->pagezero->leafpages > bt->mgr->maxleaves )
+ if( bt_promote (bt) )
+ return bt->mgr->err;
+
+ // return success
+
+ return 0;
+}
+
+// execute the source list of inserts/deletes
+
+BTERR bt_atomicexec(BtMgr *mgr, BtPage source, uint count, pid_t tid)
+{
+uint slot, src, idx, samepage, entry, outidx;
+BtPageSet set[1], prev[1];
+unsigned char value[BtId];
+BtLatchSet *latch;
+uid right_page_no;
+AtomicTxn *locks;
+BtKey *key, *ptr;
+BtPage page;
+BtVal *val;
+
+ locks = calloc (count, sizeof(AtomicTxn));
+ memset (set, 0, sizeof(BtPageSet));
+ outidx = 0;
+
+ // Load the leaf page for each key
+ // group same page references with reuse bit
+
+ for( src = 0; src++ < count; ) {
+ if( slotptr(source,src)->dead )
+ continue;
+
+ key = keyptr(source, src);
+
+ // first determine if this modification falls
+ // on the same page as the previous modification
+ // note that the far right leaf page is a special case
+
+ if( samepage = !!set->page )
+ samepage = !set->page->right || keycmp (ptr, key->key, key->len) >= 0;
+
+ if( !samepage )
+ if( slot = bt_loadpage(mgr, set, key->key, key->len, 0, BtLockWrite, tid) )
+ ptr = fenceptr(set->page), set->latch->split = 0;
+ else
+ return mgr->err;
+ else
+ slot = 0;
+
+ if( slot )
+ if( slotptr(set->page, slot)->type == Librarian )
+ slot++;
+
+ entry = set->latch - mgr->latchsets;
+ locks[outidx].reuse = samepage;
+ locks[outidx].entry = entry;
+ locks[outidx].slot = slot;
+ locks[outidx].src = src;
+ outidx++;
+ }
+
+ // insert or delete each key
+ // process any splits or merges
+ // run through txn list backwards
+
+ samepage = outidx;
+
+ for( src = outidx; src--; ) {
+ if( locks[src].reuse )
+ continue;
+
+ // perform the txn operations
+ // from smaller to larger on
+ // the same page
+
+ for( idx = src; idx < samepage; idx++ )
+ switch( slotptr(source,locks[idx].src)->type ) {
+ case Delete:
+ if( bt_atomicdelete (mgr, source, locks, idx) )
+ return mgr->err;
+ break;
+
+ case Duplicate:
+ case Unique:
+ if( bt_atomicinsert (mgr, source, locks, idx) )
+ return mgr->err;
+ break;
+
+ default:
+ bt_atomicpage (mgr, source, locks, idx, set);
+ break;
+ }
+
+ // after the same page operations have finished,
+ // process master page for splits or deletion.
+
+ latch = prev->latch = mgr->latchsets + locks[src].entry;
+ prev->page = bt_mappage (mgr, prev->latch);
+ samepage = src;
+
+ // pick-up all splits from master page
+ // each one is already pinned & WriteLocked.
+
+ while( entry = prev->latch->split ) {
+ set->latch = mgr->latchsets + entry;
+ set->page = bt_mappage (mgr, set->latch);
+
+ // delete empty master page by undoing its split
+ // (this is potentially another empty page)
+ // note that there are no pointers to it yet
+
+ if( !prev->page->act ) {
+ set->page->left = prev->page->left;
+ memcpy (prev->page, set->page, mgr->page_size << mgr->leaf_xtra);
+ bt_lockpage (BtLockDelete, set->latch, 0, __LINE__);
+ bt_lockpage (BtLockLink, set->latch, 0, __LINE__);
+ prev->latch->split = set->latch->split;
+ bt_freepage (mgr, set);
+ continue;
+ }
+
+ // remove empty split page from the split chain
+ // and return it to the free list. No other
+ // thread has its page number yet.
+
+ if( !set->page->act ) {
+ prev->page->right = set->page->right;
+ prev->latch->split = set->latch->split;
+
+ bt_lockpage (BtLockDelete, set->latch, 0, __LINE__);
+ bt_lockpage (BtLockLink, set->latch, 0, __LINE__);
+ bt_freepage (mgr, set);
+ continue;
+ }
+
+ // update prev's fence key
+
+ ptr = fenceptr(prev->page);
+ bt_putid (value, prev->latch->page_no);
+
+ if( bt_insertkey (mgr, ptr->key, ptr->len, 1, value, BtId, Unique) )
+ return mgr->err;
+
+ // splice in the left link into the split page
+
+ set->page->left = prev->latch->page_no;
+ *prev = *set;
+ }
+
+ // update left pointer in next right page from last split page
+ // (if all splits were reversed or none occurred, latch->split == 0)
+
+ if( latch->split ) {
+ // fix left pointer in master's original (now split)
+ // far right sibling or set rightmost page in page zero
+
+ if( right_page_no = prev->page->right ) {
+ if( set->latch = bt_pinlatch (mgr, right_page_no) )
+ set->page = bt_mappage (mgr, set->latch);
+ else
+ return mgr->err;
+
+ bt_lockpage (BtLockLink, set->latch, 0, __LINE__);
+ set->page->left = prev->latch->page_no;
+ bt_unlockpage (BtLockLink, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+ } else { // prev is rightmost page
+ bt_mutexlock (mgr->pagezero->lock);
+ mgr->pagezero->rightleaf = prev->latch->page_no;
+ bt_releasemutex(mgr->pagezero->lock);
+ }
+
+ // switch the original fence key from the
+ // master page to the last split page.
+
+ ptr = fenceptr(prev->page);
+ bt_putid (value, prev->latch->page_no);
+
+ if( bt_insertkey (mgr, ptr->key, ptr->len, 1, value, BtId, Update) )
+ return mgr->err;
+
+ // unlock and unpin the split pages
+
+ bt_atomicrelease (mgr, latch->split);
+
+ // unlock and unpin the master page
+
+ latch->split = 0;
+ bt_unlockpage(BtLockWrite, latch, __LINE__);
+ bt_unpinlatch(latch);
+ continue;
+ }
+
+ // since there are no splits remaining, we're
+ // finished if master page occupied
+
+ if( prev->page->act ) {
+ bt_unlockpage(BtLockWrite, prev->latch, __LINE__);
+ bt_unpinlatch(prev->latch);
+ continue;
+ }
+
+ // any and all splits were reversed, and the
+ // master page located in prev is empty, delete it
+
+ if( bt_deletepage (mgr, prev, 0) )
+ return mgr->err;
+ }
+
+ // delete the slots
+
+ for( idx = 0; idx++ < count; ) {
+ if( slotptr(source,idx)->dead )
+ continue;
+
+ slotptr(source,idx)->dead = 1;
+ source->act--;
+ }
+
+ free (locks);
+ return 0;
+}
+
+// pick & promote a page into the larger btree
+
+BTERR bt_promote (BtDb *bt)
+{
+BtPageSet set[1];
+uint slot, idx;
+BtSlot *node;
+uid page_no;
+BtKey *ptr;
+BtVal *val;
+
+ bt_mutexlock(bt->mgr->pagezero->promote);
+
+ while( 1 ) {
+ if( bt->mgr->pagezero->leafpromote < bt->mgr->pagezero->allocpage )
+ page_no = bt->mgr->pagezero->leafpromote;
+ else
+ page_no = bt->mgr->pagezero->leaf_page;
+
+ bt->mgr->pagezero->leafpromote = page_no + (1 << bt->mgr->leaf_xtra);
+
+ if( page_no < bt->mgr->pagezero->leaf_page )
+ continue;
+
+ if( set->latch = bt_pinlatch (bt->mgr, page_no) )
+ set->page = bt_mappage (bt->mgr,set->latch);
+
+ // skip upper level pages
+
+ if( set->page->lvl ) {
+ set->latch->pin--;
+ bt_releasemutex(set->latch->modify);
+ continue;
+ }
+
+ if( !bt_mutextry(set->latch->modify) ) {
+ set->latch->pin--;
+ bt_releasemutex(set->latch->modify);
+ continue;
+ }
+
+ // skip this page if it was pinned
+
+ if( set->latch->pin > 1 ) {
+ set->latch->pin--;
+ bt_releasemutex(set->latch->modify);
+ continue;
+ }
+
+ // page has no right sibling
+
+ if( !set->page->right ) {
+ set->latch->pin--;
+ bt_releasemutex(set->latch->modify);
+ continue;
+ }
+
+ // page is being killed or constructed
+
+ if( set->page->nopromote || set->page->kill ) {
+ set->latch->pin--;
+ bt_releasemutex(set->latch->modify);
+ continue;
+ }
+
+ // leave it locked for the
+ // duration of the promotion.
+
+ bt_releasemutex(bt->mgr->pagezero->promote);
+ bt_lockpage (BtLockWrite, set->latch, 0, __LINE__);
+ bt_releasemutex(set->latch->modify);
+
+ // transfer slots in our selected page to the main btree
+
+if( !((page_no>>bt->mgr->leaf_xtra)%100) )
+fprintf(stderr, "Promote page %lld, %d keys\n", page_no, set->page->act);
+
+ if( bt_atomicexec (bt->main, set->page, set->page->cnt, bt->tid) ) {
+ fprintf (stderr, "Promote error = %d line = %d\n", bt->main->err, bt->main->line);
+ return bt->main->err;
+ }
+
+ // now delete the page
+
+ if( bt_deletepage (bt->mgr, set, 0) )
+ fprintf (stderr, "Promote: delete page err = %d\n", bt->mgr->err);
+
+ return bt->mgr->err;
+ }
+}
+
+// find unique key == given key, or first duplicate key in
+// leaf level and return number of value bytes
+// or (-1) if not found.
+
+int bt_findkey (BtDb *bt, unsigned char *key, uint keylen, unsigned char *value, uint valmax)
+{
+int ret = -1, type;
+BtPageSet set[1];
+BtSlot *node;
+BtKey *ptr;
+BtVal *val;
+uint slot;
+
+ for( type = 0; type < 2; type++ )
+ if( slot = bt_loadpage (type ? bt->main : bt->mgr, set, key, keylen, 0, BtLockRead, 0) ) {
+ node = slotptr(set->page, slot);
+
+ // skip librarian slot place holder
+
+ if( node->type == Librarian )
+ node = slotptr(set->page, ++slot);
+
+ ptr = keyptr(set->page, slot);
+
+ // not there if we reach the stopper key
+ // or the key doesn't match what's on the page.
+
+ if( slot == set->page->cnt )
+ if( !set->page->right ) {
+ bt_unlockpage (BtLockRead, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+ continue;
+ }
+
+ if( keycmp (ptr, key, keylen) ) {
+ bt_unlockpage (BtLockRead, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+ continue;
+ }
+
+ // key matches, return >= 0 value bytes copied
+ // or -1 if not there.
+
+ if( node->type == Delete || node->dead ) {
+ ret = -1;
+ goto findxit;
+ }
+
+ val = valptr (set->page,slot);
+
+ if( valmax > val->len )
+ valmax = val->len;
+
+ memcpy (value, val->value, valmax);
+ ret = valmax;
+ goto findxit;
+ }
+
+ ret = -1;
+
+findxit:
+ if( type < 2 ) {
+ bt_unlockpage (BtLockRead, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+ }
+ return ret;
+}
+
+// set cursor to highest slot on right-most page
+
+BTERR bt_lastkey (BtDb *bt)
+{
+uid cache_page_no = bt->mgr->pagezero->rightleaf;
+uid main_page_no = bt->main->pagezero->rightleaf;
+
+ if( bt->cacheset->latch = bt_pinlatch (bt->mgr, cache_page_no) )
+ bt->cacheset->page = bt_mappage (bt->mgr, bt->cacheset->latch);
+ else
+ return bt->mgr->err;
+
+ bt_lockpage(BtLockRead, bt->cacheset->latch, 0, __LINE__);
+ bt->cacheslot = bt->cacheset->page->cnt;
+
+ if( bt->mainset->latch = bt_pinlatch (bt->main, main_page_no) )
+ bt->mainset->page = bt_mappage (bt->main, bt->mainset->latch);
+ else
+ return bt->main->err;
+
+ bt_lockpage(BtLockRead, bt->mainset->latch, 0, __LINE__);
+ bt->mainslot = bt->mainset->page->cnt;
+ bt->phase = 2;
+ return 0;
+}
+
+// return previous slot on cursor page
+
+uint bt_prevslot (BtMgr *mgr, BtPageSet *set, uint slot)
+{
+uid next, us = set->latch->page_no;
+
+ while( 1 ) {
+ while( --slot )
+ if( slotptr(set->page, slot)->dead )
+ continue;
+ else
+ return slot;
+
+ next = set->page->left;
+
+ if( !next )
+ return 0;
+
+ do {
+ bt_unlockpage(BtLockRead, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+
+ if( set->latch = bt_pinlatch (mgr, next) )
+ set->page = bt_mappage (mgr, set->latch);
+ else
+ return 0;
+
+ bt_lockpage(BtLockRead, set->latch, 0, __LINE__);
+ next = set->page->right;
+
+ } while( next != us );
+
+ slot = set->page->cnt + 1;
+ }
+}
+
+// advance to previous key
+
+BTERR bt_prevkey (BtDb *bt)
+{
+int cmp;
+
+ // first advance last key(s) one previous slot
+
+ while( 1 ) {
+ switch( bt->phase ) {
+ case 0:
+ bt->cacheslot = bt_prevslot (bt->mgr, bt->cacheset, bt->cacheslot);
+ break;
+ case 1:
+ bt->mainslot = bt_prevslot (bt->main, bt->mainset, bt->mainslot);
+ break;
+ case 2:
+ bt->cacheslot = bt_prevslot (bt->mgr, bt->cacheset, bt->cacheslot);
+ bt->mainslot = bt_prevslot (bt->main, bt->mainset, bt->mainslot);
+ break;
+ }
+
+ // return next key
+
+ if( bt->cacheslot ) {
+ bt->cachenode = slotptr(bt->cacheset->page, bt->cacheslot);
+ bt->cachekey = keyptr(bt->cacheset->page, bt->cacheslot);
+ bt->cacheval = valptr(bt->cacheset->page, bt->cacheslot);
+ }
+
+ if( bt->mainslot ) {
+ bt->mainnode = slotptr(bt->mainset->page, bt->mainslot);
+ bt->mainkey = keyptr(bt->mainset->page, bt->mainslot);
+ bt->mainval = valptr(bt->mainset->page, bt->mainslot);
+ }
+
+ if( bt->mainslot && bt->cacheslot )
+ cmp = keycmp (bt->cachekey, bt->mainkey->key, bt->mainkey->len);
+ else if( bt->cacheslot )
+ cmp = 1;
+ else if( bt->mainslot )
+ cmp = -1;
+ else
+ return 0;
+
+ // cache key is larger
+
+ if( cmp > 0 ) {
+ bt->phase = 0;
+ if( bt->cachenode->type == Delete )
+ continue;
+ return bt->cacheslot;
+ }
+
+ // main key is larger
+
+ if( cmp < 0 ) {
+ bt->phase = 1;
+ return bt->mainslot;
+ }
+
+ // keys are equal
+
+ bt->phase = 2;
+
+ if( bt->cachenode->type == Delete )
+ continue;
+
+ return bt->cacheslot;
+ }
+}
+
+// advance to next slot in cache or main btree
+// return 0 for EOF/error
+
+uint bt_nextslot (BtMgr *mgr, BtPageSet *set, uint slot)
+{
+BtPage page;
+uid page_no;
+
+ while( 1 ) {
+ while( slot++ < set->page->cnt )
+ if( slotptr(set->page, slot)->dead )
+ continue;
+ else if( slot < set->page->cnt || set->page->right )
+ return slot;
+ else
+ return 0;
+
+ bt_unlockpage(BtLockRead, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+
+ if( page_no = set->page->right )
+ if( set->latch = bt_pinlatch (mgr, page_no) )
+ set->page = bt_mappage (mgr, set->latch);
+ else
+ return 0;
+ else
+ return 0; // EOF
+
+ // obtain access lock using lock chaining with Access mode
+
+ bt_lockpage(BtLockAccess, set->latch, 0, __LINE__);
+ bt_lockpage(BtLockRead, set->latch, 0, __LINE__);
+ bt_unlockpage(BtLockAccess, set->latch, __LINE__);
+ slot = 0;
+ }
+}
+
+// advance to next key
+
+BTERR bt_nextkey (BtDb *bt)
+{
+int cmp;
+
+ // first advance last key(s) one next slot
+
+ while( 1 ) {
+ switch( bt->phase ) {
+ case 0:
+ bt->cacheslot = bt_nextslot (bt->mgr, bt->cacheset, bt->cacheslot);
+ break;
+ case 1:
+ bt->mainslot = bt_nextslot (bt->main, bt->mainset, bt->mainslot);
+ break;
+ case 2:
+ bt->cacheslot = bt_nextslot (bt->mgr, bt->cacheset, bt->cacheslot);
+ bt->mainslot = bt_nextslot (bt->main, bt->mainset, bt->mainslot);
+ break;
+ }
+
+ // return next key
+
+ if( bt->cacheslot ) {
+ bt->cachenode = slotptr(bt->cacheset->page, bt->cacheslot);
+ bt->cachekey = keyptr(bt->cacheset->page, bt->cacheslot);
+ bt->cacheval = valptr(bt->cacheset->page, bt->cacheslot);
+ }
+
+ if( bt->mainslot ) {
+ bt->mainnode = slotptr(bt->mainset->page, bt->mainslot);
+ bt->mainkey = keyptr(bt->mainset->page, bt->mainslot);
+ bt->mainval = valptr(bt->mainset->page, bt->mainslot);
+ }
+
+ if( bt->mainslot && bt->cacheslot )
+ cmp = keycmp (bt->cachekey, bt->mainkey->key, bt->mainkey->len);
+ else if( bt->mainslot )
+ cmp = 1;
+ else if( bt->cacheslot )
+ cmp = -1;
+ else
+ return 0;
+
+ // main key is larger
+ // return smaller key
+
+ if( cmp < 0 ) {
+ bt->phase = 0;
+ if( bt->cachenode->type == Delete )
+ continue;
+ return bt->cacheslot;
+ }
+
+ // cache key is larger
+
+ if( cmp > 0 ) {
+ bt->phase = 1;
+ return bt->mainslot;
+ }
+
+ // keys are equal
+
+ bt->phase = 2;
+
+ if( bt->cachenode->type == Delete )
+ continue;
+
+ return bt->cacheslot;
+ }
+}
+
+// start sweep of keys
+
+BTERR bt_startkey (BtDb *bt, unsigned char *key, uint len)
+{
+BtPageSet set[1];
+uint slot;
+
+ // cache btree page
+
+ if( slot = bt_loadpage (bt->mgr, bt->cacheset, key, len, 0, BtLockRead, 0) )
+ bt->cacheslot = slot - 1;
+ else
+ return bt->mgr->err;
+
+ // main btree page
+
+ if( slot = bt_loadpage (bt->main, bt->mainset, key, len, 0, BtLockRead, 0) )
+ bt->mainslot = slot - 1;
+ else
+ return bt->mgr->err;
+
+ bt->phase = 2;
+ return 0;
+}
+
+// flush cache pages to main btree
+
+BTERR bt_flushmain (BtDb *bt)
+{
+uint count, cnt = 0;
+BtPageSet set[1];
+
+ while( bt->mgr->pagezero->leafpages > 0 ) {
+ if( set->latch = bt_pinlatch (bt->mgr, bt->mgr->pagezero->leaf_page) )
+ set->page = bt_mappage (bt->mgr, set->latch);
+ else
+ return bt->mgr->err;
+
+ bt_lockpage(BtLockWrite, set->latch, 0, __LINE__);
+ count = set->page->cnt;
+
+ if( !set->page->right )
+ count--;
+
+if( !(cnt++ % 100) )
+fprintf(stderr, "Promote LEAF_page %d with %d keys\n", cnt, set->page->act);
+
+ if( bt_atomicexec (bt->main, set->page, count, bt->tid) )
+ return bt->mgr->line = bt->main->line, bt->mgr->err = bt->main->err;
+
+ if( set->page->right )
+ if( bt_deletepage (bt->mgr, set, 0) )
+ return bt->mgr->err;
+ else
+ continue;
+
+ bt_unlockpage(BtLockWrite, set->latch, __LINE__);
+ bt_unpinlatch (set->latch);
+ return 0;
+ }
+
+ // leaf page count is off
+
+ bt->mgr->line = __LINE__;
+ return bt->mgr->err = BTERR_ovflw;
+}
+
+#ifdef STANDALONE
+
+#ifndef unix
+double getCpuTime(int type)
+{
+FILETIME crtime[1];
+FILETIME xittime[1];
+FILETIME systime[1];
+FILETIME usrtime[1];
+SYSTEMTIME timeconv[1];
+double ans = 0;
+
+ memset (timeconv, 0, sizeof(SYSTEMTIME));
+
+ switch( type ) {
+ case 0:
+ GetSystemTimeAsFileTime (xittime);
+ FileTimeToSystemTime (xittime, timeconv);
+ ans = (double)timeconv->wDayOfWeek * 3600 * 24;
+ break;
+ case 1:
+ GetProcessTimes (GetCurrentProcess(), crtime, xittime, systime, usrtime);
+ FileTimeToSystemTime (usrtime, timeconv);
+ break;
+ case 2:
+ GetProcessTimes (GetCurrentProcess(), crtime, xittime, systime, usrtime);
+ FileTimeToSystemTime (systime, timeconv);
+ break;
+ }
+
+ ans += (double)timeconv->wHour * 3600;
+ ans += (double)timeconv->wMinute * 60;
+ ans += (double)timeconv->wSecond;
+ ans += (double)timeconv->wMilliseconds / 1000;
+ return ans;
+}
+#else
+#include <time.h>
+#include <sys/resource.h>
+
+double getCpuTime(int type)
+{
+struct rusage used[1];
+struct timeval tv[1];
+
+ switch( type ) {
+ case 0:
+ gettimeofday(tv, NULL);
+ return (double)tv->tv_sec + (double)tv->tv_usec / 1000000;
+
+ case 1:
+ getrusage(RUSAGE_SELF, used);
+ return (double)used->ru_utime.tv_sec + (double)used->ru_utime.tv_usec / 1000000;
+
+ case 2:
+ getrusage(RUSAGE_SELF, used);
+ return (double)used->ru_stime.tv_sec + (double)used->ru_stime.tv_usec / 1000000;
+ }
+
+ return 0;
+}
+#endif
+
+void bt_poolaudit (BtMgr *mgr, char *type)
+{
+BtLatchSet *latch, test[1];
+uint entry;
+
+ memset (test, 0, sizeof(test));
+
+ if( memcmp (test, mgr->latchsets, sizeof(test)) )
+ fprintf(stderr, "%s latchset zero overwritten\n", type);
+
+ for( entry = 0; ++entry < mgr->pagezero->latchtotal; ) {
+ latch = mgr->latchsets + entry;
+
+ if( *latch->modify->value )
+ fprintf(stderr, "%s latchset %d modifylocked for page %lld\n", type, entry, latch->page_no);
+
+ if( latch->pin )
+ fprintf(stderr, "%s latchset %d pinned %d times for page %lld\n", type, entry, latch->pin, latch->page_no);
+ }
+}
+
+typedef struct {
+ char idx;
+ char *type;
+ char *infile;
+ BtMgr *main;
+ BtMgr *mgr;
+ int num;
+} ThreadArg;
+
+// standalone program to index file of keys
+// then list them onto std-out
+
+#ifdef unix
+void *index_file (void *arg)
+#else
+uint __stdcall index_file (void *arg)
+#endif
+{
+int line = 0, found = 0, cnt = 0, cachecnt, idx;
+int ch, len = 0, slot, type = 0;
+unsigned char key[BT_maxkey];
+unsigned char buff[65536];
+uint nxt = sizeof(buff);
+ThreadArg *args = arg;
+uint counts[8][2];
+BtPageSet set[1];
+BtPage page;
+uid page_no;
+int vallen;
+BtKey *ptr;
+BtVal *val;
+uint size;
+BtDb *bt;
+FILE *in;
+
+ bt = bt_open (args->mgr, args->main);
+ page = (BtPage)buff;
+
+ if( args->idx < strlen (args->type) )
+ ch = args->type[args->idx];
+ else
+ ch = args->type[strlen(args->type) - 1];
+
+ switch(ch | 0x20)
+ {
+ case 'm':
+ fprintf(stderr, "started flushing cache to main btree\n");
+
+ if( bt->main )
+ if( bt_flushmain(bt) )
+ fprintf(stderr, "Error %d Line: %d\n", bt->mgr->err, bt->mgr->line), exit(0);
+
+ break;
+
+ case 'd':
+ type = Delete;
+
+ case 'p':
+ if( !type )
+ type = Unique;
+
+ if( args->num )
+ if( type == Delete )
+ fprintf(stderr, "started TXN pennysort delete for %s\n", args->infile);
+ else
+ fprintf(stderr, "started TXN pennysort insert for %s\n", args->infile);
+ else
+ if( type == Delete )
+ fprintf(stderr, "started pennysort delete for %s\n", args->infile);
+ else
+ fprintf(stderr, "started pennysort insert for %s\n", args->infile);
+
+ if( in = fopen (args->infile, "rb") )
+ while( ch = getc(in), ch != EOF )
+ if( ch == '\n' )
+ {
+ line++;
+
+ if( !args->num ) {
+ if( bt_insertkey (bt->mgr, key, 10, 0, key + 10, len - 10, Unique) )
+ fprintf(stderr, "Error %d Line: %d source: %d\n", bt->mgr->err, bt->mgr->line, line), exit(0);
+ len = 0;
+ continue;
+ }
+
+ nxt -= len - 10;
+ memcpy (buff + nxt, key + 10, len - 10);
+ nxt -= 1;
+ buff[nxt] = len - 10;
+ nxt -= 10;
+ memcpy (buff + nxt, key, 10);
+ nxt -= 1;
+ buff[nxt] = 10;
+ slotptr(page,++cnt)->off = nxt;
+ slotptr(page,cnt)->type = type;
+ slotptr(page,cnt)->dead = 0;
+ len = 0;
+
+ if( cnt < args->num )
+ continue;
+
+ page->cnt = cnt;
+ page->act = cnt;
+ page->min = nxt;
+
+ if( bt_atomictxn (bt, page) )
+ fprintf(stderr, "Error %d Line: %d source: %d\n", bt->mgr->err, bt->mgr->line, line), exit(0);
+ nxt = sizeof(buff);
+ cnt = 0;
+
+ }
+ else if( len < BT_maxkey )
+ key[len++] = ch;
+ fprintf(stderr, "finished %s for %d keys\n", args->infile, line);
+ break;
+
+ case 'w':
+ fprintf(stderr, "started indexing for %s\n", args->infile);
+ if( in = fopen (args->infile, "r") )
+ while( ch = getc(in), ch != EOF )
+ if( ch == '\n' )
+ {
+ line++;
+
+ if( bt_insertkey (bt->mgr, key, len, 0, NULL, 0, Unique) )
+ fprintf(stderr, "Error %d Line: %d source: %d\n", bt->mgr->err, bt->mgr->line, line), exit(0);
+ len = 0;
+ }
+ else if( len < BT_maxkey )
+ key[len++] = ch;
+ fprintf(stderr, "finished %s for %d keys\n", args->infile, line);
+ break;
+
+ case 'f':
+ fprintf(stderr, "started finding keys for %s\n", args->infile);
+ if( in = fopen (args->infile, "rb") )
+ while( ch = getc(in), ch != EOF )
+ if( ch == '\n' )
+ {
+ line++;
+ if( bt_findkey (bt, key, len, NULL, 0) == 0 )
+ found++;
+ else if( bt->mgr->err )
+ fprintf(stderr, "Error %d Syserr %d Line: %d source: %d\n", bt->mgr->err, errno, bt->mgr->line, line), exit(0);
+ len = 0;
+ }
+ else if( len < BT_maxkey )
+ key[len++] = ch;
+ fprintf(stderr, "finished %s for %d keys, found %d\n", args->infile, line, found);
+ break;
+
+ case 's':
+ fprintf(stderr, "started forward scan\n");
+ if( bt_startkey (bt, NULL, 0) )
+ fprintf(stderr, "unable to begin scan error %d Line: %d\n", bt->mgr->err, bt->mgr->line);
+
+ while( bt_nextkey (bt) ) {
+ if( bt->phase == 1 ) {
+ len = bt->mainkey->len;
+
+ if( bt->mainnode->type == Duplicate )
+ len -= BtId;
+
+ fwrite (bt->mainkey->key, len, 1, stdout);
+ fwrite (bt->mainval->value, bt->mainval->len, 1, stdout);
+ } else {
+ len = bt->cachekey->len;
+
+ if( bt->cachenode->type == Duplicate )
+ len -= BtId;
+
+ fwrite (bt->cachekey->key, len, 1, stdout);
+ fwrite (bt->cacheval->value, bt->cacheval->len, 1, stdout);
+ }
+
+ fputc ('\n', stdout);
+ cnt++;
+ }
+
+ bt_unlockpage(BtLockRead, bt->cacheset->latch, __LINE__);
+ bt_unpinlatch (bt->cacheset->latch);
+
+ bt_unlockpage(BtLockRead, bt->mainset->latch, __LINE__);
+ bt_unpinlatch (bt->mainset->latch);
+
+ fprintf(stderr, " Total keys read %d\n", cnt);
+ break;
+
+ case 'r':
+ fprintf(stderr, "started reverse scan\n");
+ if( bt_lastkey (bt) )
+ fprintf(stderr, "unable to begin scan error %d Line: %d\n", bt->mgr->err, bt->mgr->line);
+
+ while( bt_prevkey (bt) ) {
+ if( bt->phase == 1 ) {
+ len = bt->mainkey->len;
+
+ if( bt->mainnode->type == Duplicate )
+ len -= BtId;
+
+ fwrite (bt->mainkey->key, len, 1, stdout);
+ fwrite (bt->mainval->value, bt->mainval->len, 1, stdout);
+ } else {
+ len = bt->cachekey->len;
+
+ if( bt->cachenode->type == Duplicate )
+ len -= BtId;
+
+ fwrite (bt->cachekey->key, len, 1, stdout);
+ fwrite (bt->cacheval->value, bt->cacheval->len, 1, stdout);
+ }
+
+ fputc ('\n', stdout);
+ cnt++;
+ }
+
+ bt_unlockpage(BtLockRead, bt->cacheset->latch, __LINE__);
+ bt_unpinlatch (bt->cacheset->latch);
+
+ bt_unlockpage(BtLockRead, bt->mainset->latch, __LINE__);
+ bt_unpinlatch (bt->mainset->latch);
+
+ fprintf(stderr, " Total keys read %d\n", cnt);
+ break;
+
+ case 'c':
+ fprintf(stderr, "started counting LSM cache btree\n");
+ memset (counts, 0, sizeof(counts));
+ page_no = bt->mgr->pagezero->leaf_page;
+
+ size = bt->mgr->page_size << bt->mgr->leaf_xtra;
+ page = malloc(size);
+
+#ifdef unix
+ posix_fadvise( bt->mgr->idx, 0, 0, POSIX_FADV_SEQUENTIAL);
+#endif
+ while( page_no < bt->mgr->pagezero->allocpage ) {
+ if( bt_readpage (bt->mgr, page, page_no, 0) )
+ fprintf(stderr, "Unable to read page %lld from cache\n", page_no), exit(1);
+ if( !page->lvl && !page->free ) {
+ cnt += page->act;
+
+ for( idx = 0; idx++ < page->cnt; ) {
+ BtSlot *node = slotptr (page, idx);
+ counts[node->type][node->dead]++;
+ }
+ }
+ page_no += 1 << bt->mgr->leaf_xtra;
+ }
+
+ cachecnt = --cnt; // remove stopper key
+ counts[Unique][0]--;
+
+ fprintf(stderr, " Unique : %d dead: %d\n", counts[Unique][0], counts[Unique][1]);
+ fprintf(stderr, " Duplicates: %d dead: %d\n", counts[Duplicate][0], counts[Duplicate][1]);
+ fprintf(stderr, " Librarian : %d dead: %d\n", counts[Librarian][0], counts[Librarian][1]);
+ fprintf(stderr, " Deletion : %d dead: %d\n", counts[Delete][0], counts[Delete][1]);
+ fprintf(stderr, "total cache keys count: %d\n", cachecnt);
+ free (page);
+
+ fprintf(stderr, "started counting LSM main btree\n");
+ memset (counts, 0, sizeof(counts));
+ size = bt->main->page_size << bt->main->leaf_xtra;
+ page_no = bt->mgr->pagezero->leaf_page;
+ page = malloc(size);
+ cnt = 0;
+
+#ifdef unix
+ posix_fadvise( bt->main->idx, 0, 0, POSIX_FADV_SEQUENTIAL);
+#endif
+ while( page_no < bt->main->pagezero->allocpage ) {
+ if( bt_readpage (bt->main, page, page_no, 0) )
+ fprintf(stderr, "Unable to read page %lld from main\n", page_no), exit(1);
+ if( !page->lvl && !page->free ) {
+ cnt += page->act;
+
+ for( idx = 0; idx++ < page->cnt; ) {
+ BtSlot *node = slotptr (page, idx);
+ counts[node->type][node->dead]++;
+ }
+ }
+ page_no += 1 << bt->main->leaf_xtra;
+ }
+
+ cnt--; // remove stopper key
+ counts[Unique][0]--;
+
+ fprintf(stderr, " Unique : %d dead: %d\n", counts[Unique][0], counts[Unique][1]);
+ fprintf(stderr, " Duplicates: %d dead: %d\n", counts[Duplicate][0], counts[Duplicate][1]);
+ fprintf(stderr, " Librarian : %d dead: %d\n", counts[Librarian][0], counts[Librarian][1]);
+ fprintf(stderr, " Deletion : %d dead: %d\n", counts[Delete][0], counts[Delete][1]);
+ fprintf(stderr, "total main keys count : %d\n", cnt);
+ fprintf(stderr, "Total keys counted : %d\n", cnt + cachecnt);
+ free (page);
+ break;
+ }
+
+ bt_close (bt);
+#ifdef unix
+ return NULL;
+#else
+ return 0;
+#endif
+}
+
+typedef struct timeval timer;
+
+int main (int argc, char **argv)
+{
+int idx, cnt, len, slot, err;
+double start, stop;
+#ifdef unix
+pthread_t *threads;
+#else
+HANDLE *threads;
+#endif
+ThreadArg *args;
+uint mainleafpool = 0;
+uint mainleafxtra = 0;
+uint maxleaves = 0;
+uint poolsize = 0;
+uint leafpool = 0;
+uint leafxtra = 0;
+uint mainpool = 0;
+uint mainbits = 0;
+int bits = 16;
+float elapsed;
+int num = 0;
+char key[1];
+BtMgr *main;
+BtMgr *mgr;
+BtKey *ptr;
+
+ if( argc < 3 ) {
+ fprintf (stderr, "Usage: %s idx_file main_file cmds [pagebits leafbits poolsize txnsize mainbits mainleafbits mainpool maxleaves src_file1 src_file2 ... ]\n", argv[0]);
+ fprintf (stderr, " where idx_file is the name of the cache btree file\n");
+ fprintf (stderr, " where main_file is the name of the main btree file\n");
+ fprintf (stderr, " cmds is a string of (r)ev scan/(w)rite/(s)can/(d)elete/(f)ind/(p)ennysort/(c)ount/(m)ainflush, with a one character command for each input src_file. A command can also be given with no input file\n");
+ fprintf (stderr, " pagebits is the page size in bits for the cache btree\n");
+ fprintf (stderr, " leafbits is the number of xtra bits for a leaf page\n");
+ fprintf (stderr, " poolsize is the number of latches in latch pool for the cache btree\n");
+ fprintf (stderr, " txnsize = n to block transactions into n units, or zero for no transactions\n");
+ fprintf (stderr, " mainbits is the page size of the main btree in bits\n");
+ fprintf (stderr, " mainpool is the number of latches in the main latch pool\n");
+ fprintf (stderr, " maxleaves is the threashold for LSM leaf page promotion\n");
+ fprintf (stderr, " src_file1 thru src_filen are files of keys separated by newline\n");
+ exit(0);
+ }
+
+ start = getCpuTime(0);
+
+ if( argc > 4 )
+ bits = atoi(argv[4]);
+
+ if( argc > 5 )
+ leafxtra = atoi(argv[5]);
+
+ if( argc > 6 )
+ poolsize = atoi(argv[6]);
+
+ if( argc > 7 )
+ num = atoi(argv[7]);
+
+ if( argc > 8 )
+ mainbits = atoi(argv[8]);
+
+ if( argc > 9 )
+ mainleafxtra = atoi(argv[9]);
+
+ if( argc > 10 )
+ mainpool = atoi(argv[10]);
+
+ if( argc > 11 )
+ maxleaves = atoi(argv[11]);
+
+ if( argc > 12 )
+ cnt = argc - 12;
+ else
+ cnt = 0;
+
+#ifdef unix
+ threads = malloc (cnt * sizeof(pthread_t));
+#else
+ threads = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, cnt * sizeof(HANDLE));
+#endif
+ args = malloc ((cnt + 1) * sizeof(ThreadArg));
+
+ mgr = bt_mgr (argv[1], bits, leafxtra, poolsize);
+
+ if( !mgr ) {
+ fprintf(stderr, "Index Open Error %s\n", argv[1]);
+ exit (1);
+ } else {
+ mgr->maxleaves = maxleaves;
+ mgr->type = 0;
+ }
+
+ main = bt_mgr (argv[2], mainbits, mainleafxtra, mainpool);
+
+ if( !main ) {
+ fprintf(stderr, "Index Open Error %s\n", argv[2]);
+ exit (1);
+ } else
+ main->type = 1;
+
+ // fire off threads
+
+ if( cnt > 0 )
+ for( idx = 0; idx < cnt; idx++ ) {
+ args[idx].infile = argv[idx + 12];
+ args[idx].type = argv[3];
+ args[idx].main = main;
+ args[idx].mgr = mgr;
+ args[idx].num = num;
+ args[idx].idx = idx;
+#ifdef unix
+ if( err = pthread_create (threads + idx, NULL, index_file, args + idx) )
+ fprintf(stderr, "Error creating thread %d\n", err);
+#else
+ threads[idx] = (HANDLE)_beginthreadex(NULL, 131072, index_file, args + idx, 0, NULL);
+#endif
+ }
+ else {
+ args[0].type = argv[3];
+ args[0].main = main;
+ args[0].mgr = mgr;
+ args[0].num = num;
+ args[0].idx = 0;
+ index_file (args);
+ }
+
+ // wait for termination
+
+#ifdef unix
+ for( idx = 0; idx < cnt; idx++ )
+ pthread_join (threads[idx], NULL);
+#else
+ WaitForMultipleObjects (cnt, threads, TRUE, INFINITE);
+
+ for( idx = 0; idx < cnt; idx++ )
+ CloseHandle(threads[idx]);
+#endif
+ bt_poolaudit(mgr, "cache");
+
+ if( main )
+ bt_poolaudit(main, "main");
+
+ fprintf(stderr, "cache %lld leaves %lld upper %d found\n", mgr->pagezero->leafpages, mgr->pagezero->upperpages, mgr->found);
+ if( main )
+ fprintf(stderr, "main %lld leaves %lld upper %d found\n", main->pagezero->leafpages, main->pagezero->upperpages, main->found);
+
+ bt_mgrclose (mgr);
+
+ if( main )
+ bt_mgrclose (main);
+
+ elapsed = getCpuTime(0) - start;
+ fprintf(stderr, " real %dm%.3fs\n", (int)(elapsed/60), elapsed - (int)(elapsed/60)*60);
+ elapsed = getCpuTime(1);
+ fprintf(stderr, " user %dm%.3fs\n", (int)(elapsed/60), elapsed - (int)(elapsed/60)*60);
+ elapsed = getCpuTime(2);
+ fprintf(stderr, " sys %dm%.3fs\n", (int)(elapsed/60), elapsed - (int)(elapsed/60)*60);
+}
+
+BtKey *bt_fence (BtPage page)
+{
+return fenceptr(page);
+}
+
+BtKey *bt_key (BtPage page, uint slot)
+{
+return keyptr(page,slot);
+}
+
+BtSlot *bt_slot (BtPage page, uint slot)
+{
+return slotptr(page,slot);
+}
+#endif //STANDALONE
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