1.1 --- a/extensions/sqlite/sqlite-source/callback.c Fri Mar 28 06:21:34 2008 +0000
1.2 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000
1.3 @@ -1,378 +0,0 @@
1.4 -/*
1.5 -** 2005 May 23
1.6 -**
1.7 -** The author disclaims copyright to this source code. In place of
1.8 -** a legal notice, here is a blessing:
1.9 -**
1.10 -** May you do good and not evil.
1.11 -** May you find forgiveness for yourself and forgive others.
1.12 -** May you share freely, never taking more than you give.
1.13 -**
1.14 -*************************************************************************
1.15 -**
1.16 -** This file contains functions used to access the internal hash tables
1.17 -** of user defined functions and collation sequences.
1.18 -**
1.19 -** $Id$
1.20 -*/
1.21 -
1.22 -#include "sqliteInt.h"
1.23 -
1.24 -/*
1.25 -** Invoke the 'collation needed' callback to request a collation sequence
1.26 -** in the database text encoding of name zName, length nName.
1.27 -** If the collation sequence
1.28 -*/
1.29 -static void callCollNeeded(sqlite3 *db, const char *zName, int nName){
1.30 - assert( !db->xCollNeeded || !db->xCollNeeded16 );
1.31 - if( nName<0 ) nName = strlen(zName);
1.32 - if( db->xCollNeeded ){
1.33 - char *zExternal = sqlite3DbStrNDup(db, zName, nName);
1.34 - if( !zExternal ) return;
1.35 - db->xCollNeeded(db->pCollNeededArg, db, (int)ENC(db), zExternal);
1.36 - sqlite3_free(zExternal);
1.37 - }
1.38 -#ifndef SQLITE_OMIT_UTF16
1.39 - if( db->xCollNeeded16 ){
1.40 - char const *zExternal;
1.41 - sqlite3_value *pTmp = sqlite3ValueNew(db);
1.42 - sqlite3ValueSetStr(pTmp, nName, zName, SQLITE_UTF8, SQLITE_STATIC);
1.43 - zExternal = sqlite3ValueText(pTmp, SQLITE_UTF16NATIVE);
1.44 - if( zExternal ){
1.45 - db->xCollNeeded16(db->pCollNeededArg, db, (int)ENC(db), zExternal);
1.46 - }
1.47 - sqlite3ValueFree(pTmp);
1.48 - }
1.49 -#endif
1.50 -}
1.51 -
1.52 -/*
1.53 -** This routine is called if the collation factory fails to deliver a
1.54 -** collation function in the best encoding but there may be other versions
1.55 -** of this collation function (for other text encodings) available. Use one
1.56 -** of these instead if they exist. Avoid a UTF-8 <-> UTF-16 conversion if
1.57 -** possible.
1.58 -*/
1.59 -static int synthCollSeq(sqlite3 *db, CollSeq *pColl){
1.60 - CollSeq *pColl2;
1.61 - char *z = pColl->zName;
1.62 - int n = strlen(z);
1.63 - int i;
1.64 - static const u8 aEnc[] = { SQLITE_UTF16BE, SQLITE_UTF16LE, SQLITE_UTF8 };
1.65 - for(i=0; i<3; i++){
1.66 - pColl2 = sqlite3FindCollSeq(db, aEnc[i], z, n, 0);
1.67 - if( pColl2->xCmp!=0 ){
1.68 - memcpy(pColl, pColl2, sizeof(CollSeq));
1.69 - pColl->xDel = 0; /* Do not copy the destructor */
1.70 - return SQLITE_OK;
1.71 - }
1.72 - }
1.73 - return SQLITE_ERROR;
1.74 -}
1.75 -
1.76 -/*
1.77 -** This function is responsible for invoking the collation factory callback
1.78 -** or substituting a collation sequence of a different encoding when the
1.79 -** requested collation sequence is not available in the database native
1.80 -** encoding.
1.81 -**
1.82 -** If it is not NULL, then pColl must point to the database native encoding
1.83 -** collation sequence with name zName, length nName.
1.84 -**
1.85 -** The return value is either the collation sequence to be used in database
1.86 -** db for collation type name zName, length nName, or NULL, if no collation
1.87 -** sequence can be found.
1.88 -*/
1.89 -CollSeq *sqlite3GetCollSeq(
1.90 - sqlite3* db,
1.91 - CollSeq *pColl,
1.92 - const char *zName,
1.93 - int nName
1.94 -){
1.95 - CollSeq *p;
1.96 -
1.97 - p = pColl;
1.98 - if( !p ){
1.99 - p = sqlite3FindCollSeq(db, ENC(db), zName, nName, 0);
1.100 - }
1.101 - if( !p || !p->xCmp ){
1.102 - /* No collation sequence of this type for this encoding is registered.
1.103 - ** Call the collation factory to see if it can supply us with one.
1.104 - */
1.105 - callCollNeeded(db, zName, nName);
1.106 - p = sqlite3FindCollSeq(db, ENC(db), zName, nName, 0);
1.107 - }
1.108 - if( p && !p->xCmp && synthCollSeq(db, p) ){
1.109 - p = 0;
1.110 - }
1.111 - assert( !p || p->xCmp );
1.112 - return p;
1.113 -}
1.114 -
1.115 -/*
1.116 -** This routine is called on a collation sequence before it is used to
1.117 -** check that it is defined. An undefined collation sequence exists when
1.118 -** a database is loaded that contains references to collation sequences
1.119 -** that have not been defined by sqlite3_create_collation() etc.
1.120 -**
1.121 -** If required, this routine calls the 'collation needed' callback to
1.122 -** request a definition of the collating sequence. If this doesn't work,
1.123 -** an equivalent collating sequence that uses a text encoding different
1.124 -** from the main database is substituted, if one is available.
1.125 -*/
1.126 -int sqlite3CheckCollSeq(Parse *pParse, CollSeq *pColl){
1.127 - if( pColl ){
1.128 - const char *zName = pColl->zName;
1.129 - CollSeq *p = sqlite3GetCollSeq(pParse->db, pColl, zName, -1);
1.130 - if( !p ){
1.131 - if( pParse->nErr==0 ){
1.132 - sqlite3ErrorMsg(pParse, "no such collation sequence: %s", zName);
1.133 - }
1.134 - pParse->nErr++;
1.135 - return SQLITE_ERROR;
1.136 - }
1.137 - assert( p==pColl );
1.138 - }
1.139 - return SQLITE_OK;
1.140 -}
1.141 -
1.142 -
1.143 -
1.144 -/*
1.145 -** Locate and return an entry from the db.aCollSeq hash table. If the entry
1.146 -** specified by zName and nName is not found and parameter 'create' is
1.147 -** true, then create a new entry. Otherwise return NULL.
1.148 -**
1.149 -** Each pointer stored in the sqlite3.aCollSeq hash table contains an
1.150 -** array of three CollSeq structures. The first is the collation sequence
1.151 -** prefferred for UTF-8, the second UTF-16le, and the third UTF-16be.
1.152 -**
1.153 -** Stored immediately after the three collation sequences is a copy of
1.154 -** the collation sequence name. A pointer to this string is stored in
1.155 -** each collation sequence structure.
1.156 -*/
1.157 -static CollSeq *findCollSeqEntry(
1.158 - sqlite3 *db,
1.159 - const char *zName,
1.160 - int nName,
1.161 - int create
1.162 -){
1.163 - CollSeq *pColl;
1.164 - if( nName<0 ) nName = strlen(zName);
1.165 - pColl = sqlite3HashFind(&db->aCollSeq, zName, nName);
1.166 -
1.167 - if( 0==pColl && create ){
1.168 - pColl = sqlite3DbMallocZero(db, 3*sizeof(*pColl) + nName + 1 );
1.169 - if( pColl ){
1.170 - CollSeq *pDel = 0;
1.171 - pColl[0].zName = (char*)&pColl[3];
1.172 - pColl[0].enc = SQLITE_UTF8;
1.173 - pColl[1].zName = (char*)&pColl[3];
1.174 - pColl[1].enc = SQLITE_UTF16LE;
1.175 - pColl[2].zName = (char*)&pColl[3];
1.176 - pColl[2].enc = SQLITE_UTF16BE;
1.177 - memcpy(pColl[0].zName, zName, nName);
1.178 - pColl[0].zName[nName] = 0;
1.179 - pDel = sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, nName, pColl);
1.180 -
1.181 - /* If a malloc() failure occured in sqlite3HashInsert(), it will
1.182 - ** return the pColl pointer to be deleted (because it wasn't added
1.183 - ** to the hash table).
1.184 - */
1.185 - assert( pDel==0 || pDel==pColl );
1.186 - if( pDel!=0 ){
1.187 - db->mallocFailed = 1;
1.188 - sqlite3_free(pDel);
1.189 - pColl = 0;
1.190 - }
1.191 - }
1.192 - }
1.193 - return pColl;
1.194 -}
1.195 -
1.196 -/*
1.197 -** Parameter zName points to a UTF-8 encoded string nName bytes long.
1.198 -** Return the CollSeq* pointer for the collation sequence named zName
1.199 -** for the encoding 'enc' from the database 'db'.
1.200 -**
1.201 -** If the entry specified is not found and 'create' is true, then create a
1.202 -** new entry. Otherwise return NULL.
1.203 -**
1.204 -** A separate function sqlite3LocateCollSeq() is a wrapper around
1.205 -** this routine. sqlite3LocateCollSeq() invokes the collation factory
1.206 -** if necessary and generates an error message if the collating sequence
1.207 -** cannot be found.
1.208 -*/
1.209 -CollSeq *sqlite3FindCollSeq(
1.210 - sqlite3 *db,
1.211 - u8 enc,
1.212 - const char *zName,
1.213 - int nName,
1.214 - int create
1.215 -){
1.216 - CollSeq *pColl;
1.217 - if( zName ){
1.218 - pColl = findCollSeqEntry(db, zName, nName, create);
1.219 - }else{
1.220 - pColl = db->pDfltColl;
1.221 - }
1.222 - assert( SQLITE_UTF8==1 && SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
1.223 - assert( enc>=SQLITE_UTF8 && enc<=SQLITE_UTF16BE );
1.224 - if( pColl ) pColl += enc-1;
1.225 - return pColl;
1.226 -}
1.227 -
1.228 -/*
1.229 -** Locate a user function given a name, a number of arguments and a flag
1.230 -** indicating whether the function prefers UTF-16 over UTF-8. Return a
1.231 -** pointer to the FuncDef structure that defines that function, or return
1.232 -** NULL if the function does not exist.
1.233 -**
1.234 -** If the createFlag argument is true, then a new (blank) FuncDef
1.235 -** structure is created and liked into the "db" structure if a
1.236 -** no matching function previously existed. When createFlag is true
1.237 -** and the nArg parameter is -1, then only a function that accepts
1.238 -** any number of arguments will be returned.
1.239 -**
1.240 -** If createFlag is false and nArg is -1, then the first valid
1.241 -** function found is returned. A function is valid if either xFunc
1.242 -** or xStep is non-zero.
1.243 -**
1.244 -** If createFlag is false, then a function with the required name and
1.245 -** number of arguments may be returned even if the eTextRep flag does not
1.246 -** match that requested.
1.247 -*/
1.248 -FuncDef *sqlite3FindFunction(
1.249 - sqlite3 *db, /* An open database */
1.250 - const char *zName, /* Name of the function. Not null-terminated */
1.251 - int nName, /* Number of characters in the name */
1.252 - int nArg, /* Number of arguments. -1 means any number */
1.253 - u8 enc, /* Preferred text encoding */
1.254 - int createFlag /* Create new entry if true and does not otherwise exist */
1.255 -){
1.256 - FuncDef *p; /* Iterator variable */
1.257 - FuncDef *pFirst; /* First function with this name */
1.258 - FuncDef *pBest = 0; /* Best match found so far */
1.259 - int bestmatch = 0;
1.260 -
1.261 -
1.262 - assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
1.263 - if( nArg<-1 ) nArg = -1;
1.264 -
1.265 - pFirst = (FuncDef*)sqlite3HashFind(&db->aFunc, zName, nName);
1.266 - for(p=pFirst; p; p=p->pNext){
1.267 - /* During the search for the best function definition, bestmatch is set
1.268 - ** as follows to indicate the quality of the match with the definition
1.269 - ** pointed to by pBest:
1.270 - **
1.271 - ** 0: pBest is NULL. No match has been found.
1.272 - ** 1: A variable arguments function that prefers UTF-8 when a UTF-16
1.273 - ** encoding is requested, or vice versa.
1.274 - ** 2: A variable arguments function that uses UTF-16BE when UTF-16LE is
1.275 - ** requested, or vice versa.
1.276 - ** 3: A variable arguments function using the same text encoding.
1.277 - ** 4: A function with the exact number of arguments requested that
1.278 - ** prefers UTF-8 when a UTF-16 encoding is requested, or vice versa.
1.279 - ** 5: A function with the exact number of arguments requested that
1.280 - ** prefers UTF-16LE when UTF-16BE is requested, or vice versa.
1.281 - ** 6: An exact match.
1.282 - **
1.283 - ** A larger value of 'matchqual' indicates a more desirable match.
1.284 - */
1.285 - if( p->nArg==-1 || p->nArg==nArg || nArg==-1 ){
1.286 - int match = 1; /* Quality of this match */
1.287 - if( p->nArg==nArg || nArg==-1 ){
1.288 - match = 4;
1.289 - }
1.290 - if( enc==p->iPrefEnc ){
1.291 - match += 2;
1.292 - }
1.293 - else if( (enc==SQLITE_UTF16LE && p->iPrefEnc==SQLITE_UTF16BE) ||
1.294 - (enc==SQLITE_UTF16BE && p->iPrefEnc==SQLITE_UTF16LE) ){
1.295 - match += 1;
1.296 - }
1.297 -
1.298 - if( match>bestmatch ){
1.299 - pBest = p;
1.300 - bestmatch = match;
1.301 - }
1.302 - }
1.303 - }
1.304 -
1.305 - /* If the createFlag parameter is true, and the seach did not reveal an
1.306 - ** exact match for the name, number of arguments and encoding, then add a
1.307 - ** new entry to the hash table and return it.
1.308 - */
1.309 - if( createFlag && bestmatch<6 &&
1.310 - (pBest = sqlite3DbMallocZero(db, sizeof(*pBest)+nName))!=0 ){
1.311 - pBest->nArg = nArg;
1.312 - pBest->pNext = pFirst;
1.313 - pBest->iPrefEnc = enc;
1.314 - memcpy(pBest->zName, zName, nName);
1.315 - pBest->zName[nName] = 0;
1.316 - if( pBest==sqlite3HashInsert(&db->aFunc,pBest->zName,nName,(void*)pBest) ){
1.317 - db->mallocFailed = 1;
1.318 - sqlite3_free(pBest);
1.319 - return 0;
1.320 - }
1.321 - }
1.322 -
1.323 - if( pBest && (pBest->xStep || pBest->xFunc || createFlag) ){
1.324 - return pBest;
1.325 - }
1.326 - return 0;
1.327 -}
1.328 -
1.329 -/*
1.330 -** Free all resources held by the schema structure. The void* argument points
1.331 -** at a Schema struct. This function does not call sqlite3_free() on the
1.332 -** pointer itself, it just cleans up subsiduary resources (i.e. the contents
1.333 -** of the schema hash tables).
1.334 -*/
1.335 -void sqlite3SchemaFree(void *p){
1.336 - Hash temp1;
1.337 - Hash temp2;
1.338 - HashElem *pElem;
1.339 - Schema *pSchema = (Schema *)p;
1.340 -
1.341 - temp1 = pSchema->tblHash;
1.342 - temp2 = pSchema->trigHash;
1.343 - sqlite3HashInit(&pSchema->trigHash, SQLITE_HASH_STRING, 0);
1.344 - sqlite3HashClear(&pSchema->aFKey);
1.345 - sqlite3HashClear(&pSchema->idxHash);
1.346 - for(pElem=sqliteHashFirst(&temp2); pElem; pElem=sqliteHashNext(pElem)){
1.347 - sqlite3DeleteTrigger((Trigger*)sqliteHashData(pElem));
1.348 - }
1.349 - sqlite3HashClear(&temp2);
1.350 - sqlite3HashInit(&pSchema->tblHash, SQLITE_HASH_STRING, 0);
1.351 - for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){
1.352 - Table *pTab = sqliteHashData(pElem);
1.353 - sqlite3DeleteTable(pTab);
1.354 - }
1.355 - sqlite3HashClear(&temp1);
1.356 - pSchema->pSeqTab = 0;
1.357 - pSchema->flags &= ~DB_SchemaLoaded;
1.358 -}
1.359 -
1.360 -/*
1.361 -** Find and return the schema associated with a BTree. Create
1.362 -** a new one if necessary.
1.363 -*/
1.364 -Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){
1.365 - Schema * p;
1.366 - if( pBt ){
1.367 - p = (Schema *)sqlite3BtreeSchema(pBt, sizeof(Schema), sqlite3SchemaFree);
1.368 - }else{
1.369 - p = (Schema *)sqlite3MallocZero(sizeof(Schema));
1.370 - }
1.371 - if( !p ){
1.372 - db->mallocFailed = 1;
1.373 - }else if ( 0==p->file_format ){
1.374 - sqlite3HashInit(&p->tblHash, SQLITE_HASH_STRING, 0);
1.375 - sqlite3HashInit(&p->idxHash, SQLITE_HASH_STRING, 0);
1.376 - sqlite3HashInit(&p->trigHash, SQLITE_HASH_STRING, 0);
1.377 - sqlite3HashInit(&p->aFKey, SQLITE_HASH_STRING, 1);
1.378 - p->enc = SQLITE_UTF8;
1.379 - }
1.380 - return p;
1.381 -}
