Index: third_party/sqlite/sqlite-src-3080704/ext/fts3/fts3_hash.c |
diff --git a/third_party/sqlite/sqlite-src-3080704/ext/fts3/fts3_hash.c b/third_party/sqlite/sqlite-src-3080704/ext/fts3/fts3_hash.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..1a32a537b406947c89efe383e338a651ed655936 |
--- /dev/null |
+++ b/third_party/sqlite/sqlite-src-3080704/ext/fts3/fts3_hash.c |
@@ -0,0 +1,383 @@ |
+/* |
+** 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). |
+*/ |
+#include "fts3Int.h" |
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) |
+ |
+#include <assert.h> |
+#include <stdlib.h> |
+#include <string.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, char keyClass, char 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; |
+ unsigned h = 0; |
+ if( nKey<=0 ) nKey = (int) strlen(z); |
+ while( nKey > 0 ){ |
+ h = (h<<3) ^ h ^ *z++; |
+ nKey--; |
+ } |
+ return (int)(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. |
+** |
+** Return non-zero if a memory allocation error occurs. |
+*/ |
+static int 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 1; |
+ 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); |
+ } |
+ return 0; |
+} |
+ |
+/* 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); |
+ } |
+} |
+ |
+Fts3HashElem *sqlite3Fts3HashFindElem( |
+ const Fts3Hash *pH, |
+ const void *pKey, |
+ int nKey |
+){ |
+ int h; /* A hash on 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 ); |
+ return fts3FindElementByHash(pH,pKey,nKey, h & (pH->htsize-1)); |
+} |
+ |
+/* |
+** 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){ |
+ Fts3HashElem *pElem; /* The element that matches key (if any) */ |
+ |
+ pElem = sqlite3Fts3HashFindElem(pH, pKey, nKey); |
+ return pElem ? pElem->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)) |
+ || (pH->count>=pH->htsize && fts3Rehash(pH, pH->htsize*2)) |
+ ){ |
+ pH->count = 0; |
+ return data; |
+ } |
+ assert( pH->htsize>0 ); |
+ 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++; |
+ 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) */ |