| Index: third_party/sqlite/ext/fts3/fts3_hash.c
|
| ===================================================================
|
| --- third_party/sqlite/ext/fts3/fts3_hash.c (revision 56608)
|
| +++ third_party/sqlite/ext/fts3/fts3_hash.c (working copy)
|
| @@ -1,373 +0,0 @@
|
| -/*
|
| -** 2001 September 22
|
| -**
|
| -** The author disclaims copyright to this source code. In place of
|
| -** a legal notice, here is a blessing:
|
| -**
|
| -** May you do good and not evil.
|
| -** May you find forgiveness for yourself and forgive others.
|
| -** May you share freely, never taking more than you give.
|
| -**
|
| -*************************************************************************
|
| -** This is the implementation of generic hash-tables used in SQLite.
|
| -** We've modified it slightly to serve as a standalone hash table
|
| -** implementation for the full-text indexing module.
|
| -*/
|
| -
|
| -/*
|
| -** The code in this file is only compiled if:
|
| -**
|
| -** * The FTS3 module is being built as an extension
|
| -** (in which case SQLITE_CORE is not defined), or
|
| -**
|
| -** * The FTS3 module is being built into the core of
|
| -** SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
|
| -*/
|
| -#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
|
| -
|
| -#include <assert.h>
|
| -#include <stdlib.h>
|
| -#include <string.h>
|
| -
|
| -#include "sqlite3.h"
|
| -#include "fts3_hash.h"
|
| -
|
| -/*
|
| -** Malloc and Free functions
|
| -*/
|
| -static void *fts3HashMalloc(int n){
|
| - void *p = sqlite3_malloc(n);
|
| - if( p ){
|
| - memset(p, 0, n);
|
| - }
|
| - return p;
|
| -}
|
| -static void fts3HashFree(void *p){
|
| - sqlite3_free(p);
|
| -}
|
| -
|
| -/* Turn bulk memory into a hash table object by initializing the
|
| -** fields of the Hash structure.
|
| -**
|
| -** "pNew" is a pointer to the hash table that is to be initialized.
|
| -** keyClass is one of the constants
|
| -** FTS3_HASH_BINARY or FTS3_HASH_STRING. The value of keyClass
|
| -** determines what kind of key the hash table will use. "copyKey" is
|
| -** true if the hash table should make its own private copy of keys and
|
| -** false if it should just use the supplied pointer.
|
| -*/
|
| -void sqlite3Fts3HashInit(fts3Hash *pNew, int keyClass, int copyKey){
|
| - assert( pNew!=0 );
|
| - assert( keyClass>=FTS3_HASH_STRING && keyClass<=FTS3_HASH_BINARY );
|
| - pNew->keyClass = keyClass;
|
| - pNew->copyKey = copyKey;
|
| - pNew->first = 0;
|
| - pNew->count = 0;
|
| - pNew->htsize = 0;
|
| - pNew->ht = 0;
|
| -}
|
| -
|
| -/* Remove all entries from a hash table. Reclaim all memory.
|
| -** Call this routine to delete a hash table or to reset a hash table
|
| -** to the empty state.
|
| -*/
|
| -void sqlite3Fts3HashClear(fts3Hash *pH){
|
| - fts3HashElem *elem; /* For looping over all elements of the table */
|
| -
|
| - assert( pH!=0 );
|
| - elem = pH->first;
|
| - pH->first = 0;
|
| - fts3HashFree(pH->ht);
|
| - pH->ht = 0;
|
| - pH->htsize = 0;
|
| - while( elem ){
|
| - fts3HashElem *next_elem = elem->next;
|
| - if( pH->copyKey && elem->pKey ){
|
| - fts3HashFree(elem->pKey);
|
| - }
|
| - fts3HashFree(elem);
|
| - elem = next_elem;
|
| - }
|
| - pH->count = 0;
|
| -}
|
| -
|
| -/*
|
| -** Hash and comparison functions when the mode is FTS3_HASH_STRING
|
| -*/
|
| -static int fts3StrHash(const void *pKey, int nKey){
|
| - const char *z = (const char *)pKey;
|
| - int h = 0;
|
| - if( nKey<=0 ) nKey = (int) strlen(z);
|
| - while( nKey > 0 ){
|
| - h = (h<<3) ^ h ^ *z++;
|
| - nKey--;
|
| - }
|
| - return h & 0x7fffffff;
|
| -}
|
| -static int fts3StrCompare(const void *pKey1, int n1, const void *pKey2, int n2){
|
| - if( n1!=n2 ) return 1;
|
| - return strncmp((const char*)pKey1,(const char*)pKey2,n1);
|
| -}
|
| -
|
| -/*
|
| -** Hash and comparison functions when the mode is FTS3_HASH_BINARY
|
| -*/
|
| -static int fts3BinHash(const void *pKey, int nKey){
|
| - int h = 0;
|
| - const char *z = (const char *)pKey;
|
| - while( nKey-- > 0 ){
|
| - h = (h<<3) ^ h ^ *(z++);
|
| - }
|
| - return h & 0x7fffffff;
|
| -}
|
| -static int fts3BinCompare(const void *pKey1, int n1, const void *pKey2, int n2){
|
| - if( n1!=n2 ) return 1;
|
| - return memcmp(pKey1,pKey2,n1);
|
| -}
|
| -
|
| -/*
|
| -** Return a pointer to the appropriate hash function given the key class.
|
| -**
|
| -** The C syntax in this function definition may be unfamilar to some
|
| -** programmers, so we provide the following additional explanation:
|
| -**
|
| -** The name of the function is "ftsHashFunction". The function takes a
|
| -** single parameter "keyClass". The return value of ftsHashFunction()
|
| -** is a pointer to another function. Specifically, the return value
|
| -** of ftsHashFunction() is a pointer to a function that takes two parameters
|
| -** with types "const void*" and "int" and returns an "int".
|
| -*/
|
| -static int (*ftsHashFunction(int keyClass))(const void*,int){
|
| - if( keyClass==FTS3_HASH_STRING ){
|
| - return &fts3StrHash;
|
| - }else{
|
| - assert( keyClass==FTS3_HASH_BINARY );
|
| - return &fts3BinHash;
|
| - }
|
| -}
|
| -
|
| -/*
|
| -** Return a pointer to the appropriate hash function given the key class.
|
| -**
|
| -** For help in interpreted the obscure C code in the function definition,
|
| -** see the header comment on the previous function.
|
| -*/
|
| -static int (*ftsCompareFunction(int keyClass))(const void*,int,const void*,int){
|
| - if( keyClass==FTS3_HASH_STRING ){
|
| - return &fts3StrCompare;
|
| - }else{
|
| - assert( keyClass==FTS3_HASH_BINARY );
|
| - return &fts3BinCompare;
|
| - }
|
| -}
|
| -
|
| -/* Link an element into the hash table
|
| -*/
|
| -static void fts3HashInsertElement(
|
| - fts3Hash *pH, /* The complete hash table */
|
| - struct _fts3ht *pEntry, /* The entry into which pNew is inserted */
|
| - fts3HashElem *pNew /* The element to be inserted */
|
| -){
|
| - fts3HashElem *pHead; /* First element already in pEntry */
|
| - pHead = pEntry->chain;
|
| - if( pHead ){
|
| - pNew->next = pHead;
|
| - pNew->prev = pHead->prev;
|
| - if( pHead->prev ){ pHead->prev->next = pNew; }
|
| - else { pH->first = pNew; }
|
| - pHead->prev = pNew;
|
| - }else{
|
| - pNew->next = pH->first;
|
| - if( pH->first ){ pH->first->prev = pNew; }
|
| - pNew->prev = 0;
|
| - pH->first = pNew;
|
| - }
|
| - pEntry->count++;
|
| - pEntry->chain = pNew;
|
| -}
|
| -
|
| -
|
| -/* Resize the hash table so that it cantains "new_size" buckets.
|
| -** "new_size" must be a power of 2. The hash table might fail
|
| -** to resize if sqliteMalloc() fails.
|
| -*/
|
| -static void fts3Rehash(fts3Hash *pH, int new_size){
|
| - struct _fts3ht *new_ht; /* The new hash table */
|
| - fts3HashElem *elem, *next_elem; /* For looping over existing elements */
|
| - int (*xHash)(const void*,int); /* The hash function */
|
| -
|
| - assert( (new_size & (new_size-1))==0 );
|
| - new_ht = (struct _fts3ht *)fts3HashMalloc( new_size*sizeof(struct _fts3ht) );
|
| - if( new_ht==0 ) return;
|
| - fts3HashFree(pH->ht);
|
| - pH->ht = new_ht;
|
| - pH->htsize = new_size;
|
| - xHash = ftsHashFunction(pH->keyClass);
|
| - for(elem=pH->first, pH->first=0; elem; elem = next_elem){
|
| - int h = (*xHash)(elem->pKey, elem->nKey) & (new_size-1);
|
| - next_elem = elem->next;
|
| - fts3HashInsertElement(pH, &new_ht[h], elem);
|
| - }
|
| -}
|
| -
|
| -/* This function (for internal use only) locates an element in an
|
| -** hash table that matches the given key. The hash for this key has
|
| -** already been computed and is passed as the 4th parameter.
|
| -*/
|
| -static fts3HashElem *fts3FindElementByHash(
|
| - const fts3Hash *pH, /* The pH to be searched */
|
| - const void *pKey, /* The key we are searching for */
|
| - int nKey,
|
| - int h /* The hash for this key. */
|
| -){
|
| - fts3HashElem *elem; /* Used to loop thru the element list */
|
| - int count; /* Number of elements left to test */
|
| - int (*xCompare)(const void*,int,const void*,int); /* comparison function */
|
| -
|
| - if( pH->ht ){
|
| - struct _fts3ht *pEntry = &pH->ht[h];
|
| - elem = pEntry->chain;
|
| - count = pEntry->count;
|
| - xCompare = ftsCompareFunction(pH->keyClass);
|
| - while( count-- && elem ){
|
| - if( (*xCompare)(elem->pKey,elem->nKey,pKey,nKey)==0 ){
|
| - return elem;
|
| - }
|
| - elem = elem->next;
|
| - }
|
| - }
|
| - return 0;
|
| -}
|
| -
|
| -/* Remove a single entry from the hash table given a pointer to that
|
| -** element and a hash on the element's key.
|
| -*/
|
| -static void fts3RemoveElementByHash(
|
| - fts3Hash *pH, /* The pH containing "elem" */
|
| - fts3HashElem* elem, /* The element to be removed from the pH */
|
| - int h /* Hash value for the element */
|
| -){
|
| - struct _fts3ht *pEntry;
|
| - if( elem->prev ){
|
| - elem->prev->next = elem->next;
|
| - }else{
|
| - pH->first = elem->next;
|
| - }
|
| - if( elem->next ){
|
| - elem->next->prev = elem->prev;
|
| - }
|
| - pEntry = &pH->ht[h];
|
| - if( pEntry->chain==elem ){
|
| - pEntry->chain = elem->next;
|
| - }
|
| - pEntry->count--;
|
| - if( pEntry->count<=0 ){
|
| - pEntry->chain = 0;
|
| - }
|
| - if( pH->copyKey && elem->pKey ){
|
| - fts3HashFree(elem->pKey);
|
| - }
|
| - fts3HashFree( elem );
|
| - pH->count--;
|
| - if( pH->count<=0 ){
|
| - assert( pH->first==0 );
|
| - assert( pH->count==0 );
|
| - fts3HashClear(pH);
|
| - }
|
| -}
|
| -
|
| -/* Attempt to locate an element of the hash table pH with a key
|
| -** that matches pKey,nKey. Return the data for this element if it is
|
| -** found, or NULL if there is no match.
|
| -*/
|
| -void *sqlite3Fts3HashFind(const fts3Hash *pH, const void *pKey, int nKey){
|
| - int h; /* A hash on key */
|
| - fts3HashElem *elem; /* The element that matches key */
|
| - int (*xHash)(const void*,int); /* The hash function */
|
| -
|
| - if( pH==0 || pH->ht==0 ) return 0;
|
| - xHash = ftsHashFunction(pH->keyClass);
|
| - assert( xHash!=0 );
|
| - h = (*xHash)(pKey,nKey);
|
| - assert( (pH->htsize & (pH->htsize-1))==0 );
|
| - elem = fts3FindElementByHash(pH,pKey,nKey, h & (pH->htsize-1));
|
| - return elem ? elem->data : 0;
|
| -}
|
| -
|
| -/* Insert an element into the hash table pH. The key is pKey,nKey
|
| -** and the data is "data".
|
| -**
|
| -** If no element exists with a matching key, then a new
|
| -** element is created. A copy of the key is made if the copyKey
|
| -** flag is set. NULL is returned.
|
| -**
|
| -** If another element already exists with the same key, then the
|
| -** new data replaces the old data and the old data is returned.
|
| -** The key is not copied in this instance. If a malloc fails, then
|
| -** the new data is returned and the hash table is unchanged.
|
| -**
|
| -** If the "data" parameter to this function is NULL, then the
|
| -** element corresponding to "key" is removed from the hash table.
|
| -*/
|
| -void *sqlite3Fts3HashInsert(
|
| - fts3Hash *pH, /* The hash table to insert into */
|
| - const void *pKey, /* The key */
|
| - int nKey, /* Number of bytes in the key */
|
| - void *data /* The data */
|
| -){
|
| - int hraw; /* Raw hash value of the key */
|
| - int h; /* the hash of the key modulo hash table size */
|
| - fts3HashElem *elem; /* Used to loop thru the element list */
|
| - fts3HashElem *new_elem; /* New element added to the pH */
|
| - int (*xHash)(const void*,int); /* The hash function */
|
| -
|
| - assert( pH!=0 );
|
| - xHash = ftsHashFunction(pH->keyClass);
|
| - assert( xHash!=0 );
|
| - hraw = (*xHash)(pKey, nKey);
|
| - assert( (pH->htsize & (pH->htsize-1))==0 );
|
| - h = hraw & (pH->htsize-1);
|
| - elem = fts3FindElementByHash(pH,pKey,nKey,h);
|
| - if( elem ){
|
| - void *old_data = elem->data;
|
| - if( data==0 ){
|
| - fts3RemoveElementByHash(pH,elem,h);
|
| - }else{
|
| - elem->data = data;
|
| - }
|
| - return old_data;
|
| - }
|
| - if( data==0 ) return 0;
|
| - if( pH->htsize==0 ){
|
| - fts3Rehash(pH,8);
|
| - if( pH->htsize==0 ){
|
| - pH->count = 0;
|
| - return data;
|
| - }
|
| - }
|
| - new_elem = (fts3HashElem*)fts3HashMalloc( sizeof(fts3HashElem) );
|
| - if( new_elem==0 ) return data;
|
| - if( pH->copyKey && pKey!=0 ){
|
| - new_elem->pKey = fts3HashMalloc( nKey );
|
| - if( new_elem->pKey==0 ){
|
| - fts3HashFree(new_elem);
|
| - return data;
|
| - }
|
| - memcpy((void*)new_elem->pKey, pKey, nKey);
|
| - }else{
|
| - new_elem->pKey = (void*)pKey;
|
| - }
|
| - new_elem->nKey = nKey;
|
| - pH->count++;
|
| - if( pH->count > pH->htsize ){
|
| - fts3Rehash(pH,pH->htsize*2);
|
| - }
|
| - assert( pH->htsize>0 );
|
| - assert( (pH->htsize & (pH->htsize-1))==0 );
|
| - h = hraw & (pH->htsize-1);
|
| - fts3HashInsertElement(pH, &pH->ht[h], new_elem);
|
| - new_elem->data = data;
|
| - return 0;
|
| -}
|
| -
|
| -#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
|
|
|