| Index: third_party/sqlite/src/hash.c
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| ===================================================================
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| --- third_party/sqlite/src/hash.c	(revision 56608)
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| +++ third_party/sqlite/src/hash.c	(working copy)
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| @@ -1,279 +0,0 @@
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| -/*
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| -** 2001 September 22
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| -**
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| -** The author disclaims copyright to this source code.  In place of
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| -** a legal notice, here is a blessing:
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| -**
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| -**    May you do good and not evil.
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| -**    May you find forgiveness for yourself and forgive others.
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| -**    May you share freely, never taking more than you give.
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| -**
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| -*************************************************************************
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| -** This is the implementation of generic hash-tables
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| -** used in SQLite.
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| -**
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| -** $Id: hash.c,v 1.38 2009/05/09 23:29:12 drh Exp $
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| -*/
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| -#include "sqliteInt.h"
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| -#include <assert.h>
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| -
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| -/* Turn bulk memory into a hash table object by initializing the
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| -** fields of the Hash structure.
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| -**
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| -** "pNew" is a pointer to the hash table that is to be initialized.
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| -*/
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| -void sqlite3HashInit(Hash *pNew){
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| -  assert( pNew!=0 );
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| -  pNew->first = 0;
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| -  pNew->count = 0;
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| -  pNew->htsize = 0;
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| -  pNew->ht = 0;
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| -}
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| -
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| -/* Remove all entries from a hash table.  Reclaim all memory.
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| -** Call this routine to delete a hash table or to reset a hash table
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| -** to the empty state.
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| -*/
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| -void sqlite3HashClear(Hash *pH){
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| -  HashElem *elem;         /* For looping over all elements of the table */
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| -
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| -  assert( pH!=0 );
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| -  elem = pH->first;
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| -  pH->first = 0;
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| -  sqlite3_free(pH->ht);
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| -  pH->ht = 0;
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| -  pH->htsize = 0;
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| -  while( elem ){
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| -    HashElem *next_elem = elem->next;
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| -    sqlite3_free(elem);
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| -    elem = next_elem;
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| -  }
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| -  pH->count = 0;
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| -}
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| -
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| -/*
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| -** The hashing function.
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| -*/
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| -static unsigned int strHash(const char *z, int nKey){
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| -  int h = 0;
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| -  assert( nKey>=0 );
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| -  while( nKey > 0  ){
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| -    h = (h<<3) ^ h ^ sqlite3UpperToLower[(unsigned char)*z++];
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| -    nKey--;
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| -  }
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| -  return h;
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| -}
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| -
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| -
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| -/* Link pNew element into the hash table pH.  If pEntry!=0 then also
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| -** insert pNew into the pEntry hash bucket.
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| -*/
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| -static void insertElement(
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| -  Hash *pH,              /* The complete hash table */
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| -  struct _ht *pEntry,    /* The entry into which pNew is inserted */
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| -  HashElem *pNew         /* The element to be inserted */
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| -){
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| -  HashElem *pHead;       /* First element already in pEntry */
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| -  if( pEntry ){
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| -    pHead = pEntry->count ? pEntry->chain : 0;
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| -    pEntry->count++;
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| -    pEntry->chain = pNew;
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| -  }else{
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| -    pHead = 0;
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| -  }
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| -  if( pHead ){
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| -    pNew->next = pHead;
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| -    pNew->prev = pHead->prev;
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| -    if( pHead->prev ){ pHead->prev->next = pNew; }
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| -    else             { pH->first = pNew; }
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| -    pHead->prev = pNew;
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| -  }else{
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| -    pNew->next = pH->first;
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| -    if( pH->first ){ pH->first->prev = pNew; }
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| -    pNew->prev = 0;
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| -    pH->first = pNew;
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| -  }
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| -}
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| -
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| -
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| -/* Resize the hash table so that it cantains "new_size" buckets.
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| -**
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| -** The hash table might fail to resize if sqlite3_malloc() fails or
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| -** if the new size is the same as the prior size.
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| -** Return TRUE if the resize occurs and false if not.
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| -*/
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| -static int rehash(Hash *pH, unsigned int new_size){
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| -  struct _ht *new_ht;            /* The new hash table */
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| -  HashElem *elem, *next_elem;    /* For looping over existing elements */
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| -
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| -#if SQLITE_MALLOC_SOFT_LIMIT>0
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| -  if( new_size*sizeof(struct _ht)>SQLITE_MALLOC_SOFT_LIMIT ){
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| -    new_size = SQLITE_MALLOC_SOFT_LIMIT/sizeof(struct _ht);
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| -  }
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| -  if( new_size==pH->htsize ) return 0;
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| -#endif
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| -
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| -  /* The inability to allocates space for a larger hash table is
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| -  ** a performance hit but it is not a fatal error.  So mark the
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| -  ** allocation as a benign.
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| -  */
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| -  sqlite3BeginBenignMalloc();
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| -  new_ht = (struct _ht *)sqlite3Malloc( new_size*sizeof(struct _ht) );
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| -  sqlite3EndBenignMalloc();
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| -
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| -  if( new_ht==0 ) return 0;
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| -  sqlite3_free(pH->ht);
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| -  pH->ht = new_ht;
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| -  pH->htsize = new_size = sqlite3MallocSize(new_ht)/sizeof(struct _ht);
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| -  memset(new_ht, 0, new_size*sizeof(struct _ht));
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| -  for(elem=pH->first, pH->first=0; elem; elem = next_elem){
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| -    unsigned int h = strHash(elem->pKey, elem->nKey) % new_size;
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| -    next_elem = elem->next;
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| -    insertElement(pH, &new_ht[h], elem);
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| -  }
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| -  return 1;
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| -}
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| -
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| -/* This function (for internal use only) locates an element in an
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| -** hash table that matches the given key.  The hash for this key has
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| -** already been computed and is passed as the 4th parameter.
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| -*/
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| -static HashElem *findElementGivenHash(
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| -  const Hash *pH,     /* The pH to be searched */
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| -  const char *pKey,   /* The key we are searching for */
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| -  int nKey,           /* Bytes in key (not counting zero terminator) */
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| -  unsigned int h      /* The hash for this key. */
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| -){
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| -  HashElem *elem;                /* Used to loop thru the element list */
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| -  int count;                     /* Number of elements left to test */
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| -
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| -  if( pH->ht ){
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| -    struct _ht *pEntry = &pH->ht[h];
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| -    elem = pEntry->chain;
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| -    count = pEntry->count;
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| -  }else{
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| -    elem = pH->first;
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| -    count = pH->count;
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| -  }
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| -  while( count-- && ALWAYS(elem) ){
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| -    if( elem->nKey==nKey && sqlite3StrNICmp(elem->pKey,pKey,nKey)==0 ){ 
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| -      return elem;
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| -    }
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| -    elem = elem->next;
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| -  }
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| -  return 0;
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| -}
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| -
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| -/* Remove a single entry from the hash table given a pointer to that
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| -** element and a hash on the element's key.
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| -*/
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| -static void removeElementGivenHash(
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| -  Hash *pH,         /* The pH containing "elem" */
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| -  HashElem* elem,   /* The element to be removed from the pH */
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| -  unsigned int h    /* Hash value for the element */
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| -){
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| -  struct _ht *pEntry;
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| -  if( elem->prev ){
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| -    elem->prev->next = elem->next; 
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| -  }else{
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| -    pH->first = elem->next;
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| -  }
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| -  if( elem->next ){
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| -    elem->next->prev = elem->prev;
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| -  }
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| -  if( pH->ht ){
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| -    pEntry = &pH->ht[h];
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| -    if( pEntry->chain==elem ){
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| -      pEntry->chain = elem->next;
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| -    }
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| -    pEntry->count--;
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| -    assert( pEntry->count>=0 );
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| -  }
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| -  sqlite3_free( elem );
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| -  pH->count--;
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| -  if( pH->count<=0 ){
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| -    assert( pH->first==0 );
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| -    assert( pH->count==0 );
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| -    sqlite3HashClear(pH);
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| -  }
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| -}
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| -
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| -/* Attempt to locate an element of the hash table pH with a key
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| -** that matches pKey,nKey.  Return the data for this element if it is
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| -** found, or NULL if there is no match.
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| -*/
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| -void *sqlite3HashFind(const Hash *pH, const char *pKey, int nKey){
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| -  HashElem *elem;    /* The element that matches key */
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| -  unsigned int h;    /* A hash on key */
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| -
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| -  assert( pH!=0 );
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| -  assert( pKey!=0 );
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| -  assert( nKey>=0 );
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| -  if( pH->ht ){
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| -    h = strHash(pKey, nKey) % pH->htsize;
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| -  }else{
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| -    h = 0;
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| -  }
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| -  elem = findElementGivenHash(pH, pKey, nKey, h);
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| -  return elem ? elem->data : 0;
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| -}
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| -
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| -/* Insert an element into the hash table pH.  The key is pKey,nKey
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| -** and the data is "data".
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| -**
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| -** If no element exists with a matching key, then a new
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| -** element is created and NULL is returned.
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| -**
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| -** If another element already exists with the same key, then the
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| -** new data replaces the old data and the old data is returned.
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| -** The key is not copied in this instance.  If a malloc fails, then
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| -** the new data is returned and the hash table is unchanged.
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| -**
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| -** If the "data" parameter to this function is NULL, then the
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| -** element corresponding to "key" is removed from the hash table.
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| -*/
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| -void *sqlite3HashInsert(Hash *pH, const char *pKey, int nKey, void *data){
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| -  unsigned int h;       /* the hash of the key modulo hash table size */
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| -  HashElem *elem;       /* Used to loop thru the element list */
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| -  HashElem *new_elem;   /* New element added to the pH */
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| -
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| -  assert( pH!=0 );
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| -  assert( pKey!=0 );
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| -  assert( nKey>=0 );
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| -  if( pH->htsize ){
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| -    h = strHash(pKey, nKey) % pH->htsize;
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| -  }else{
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| -    h = 0;
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| -  }
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| -  elem = findElementGivenHash(pH,pKey,nKey,h);
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| -  if( elem ){
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| -    void *old_data = elem->data;
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| -    if( data==0 ){
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| -      removeElementGivenHash(pH,elem,h);
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| -    }else{
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| -      elem->data = data;
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| -      elem->pKey = pKey;
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| -      assert(nKey==elem->nKey);
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| -    }
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| -    return old_data;
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| -  }
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| -  if( data==0 ) return 0;
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| -  new_elem = (HashElem*)sqlite3Malloc( sizeof(HashElem) );
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| -  if( new_elem==0 ) return data;
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| -  new_elem->pKey = pKey;
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| -  new_elem->nKey = nKey;
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| -  new_elem->data = data;
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| -  pH->count++;
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| -  if( pH->count>=10 && pH->count > 2*pH->htsize ){
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| -    if( rehash(pH, pH->count*2) ){
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| -      assert( pH->htsize>0 );
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| -      h = strHash(pKey, nKey) % pH->htsize;
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| -    }
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| -  }
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| -  if( pH->ht ){
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| -    insertElement(pH, &pH->ht[h], new_elem);
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| -  }else{
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| -    insertElement(pH, 0, new_elem);
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| -  }
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| -  return 0;
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| -}
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| 
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