[sql] Import reference version of SQLite 3.8.7.4.

third_party/sqlite/sqlite-src-3080704/src/callback.c

 /*
 ** 2005 May 23 
 **
 ** 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.
 **
@@ skipping 57 matching lines @@
 /*
 ** This function is responsible for invoking the collation factory callback
 ** or substituting a collation sequence of a different encoding when the
 ** requested collation sequence is not available in the desired encoding.
 ** 
 ** If it is not NULL, then pColl must point to the database native encoding 
 ** collation sequence with name zName, length nName.
 **
 ** The return value is either the collation sequence to be used in database
 ** db for collation type name zName, length nName, or NULL, if no collation
-** sequence can be found.
+** sequence can be found.  If no collation is found, leave an error message.
 **
 ** See also: sqlite3LocateCollSeq(), sqlite3FindCollSeq()
 */
 CollSeq *sqlite3GetCollSeq(
-  sqlite3* db,          /* The database connection */
+  Parse *pParse,        /* Parsing context */
   u8 enc,               /* The desired encoding for the collating sequence */
   CollSeq *pColl,       /* Collating sequence with native encoding, or NULL */
   const char *zName     /* Collating sequence name */
 ){
   CollSeq *p;
+  sqlite3 *db = pParse->db;
 
   p = pColl;
   if( !p ){
     p = sqlite3FindCollSeq(db, enc, zName, 0);
   }
   if( !p || !p->xCmp ){
     /* No collation sequence of this type for this encoding is registered.
     ** Call the collation factory to see if it can supply us with one.
     */
     callCollNeeded(db, enc, zName);
     p = sqlite3FindCollSeq(db, enc, zName, 0);
   }
   if( p && !p->xCmp && synthCollSeq(db, p) ){
     p = 0;
   }
   assert( !p || p->xCmp );
+  if( p==0 ){
+    sqlite3ErrorMsg(pParse, "no such collation sequence: %s", zName);
+  }
   return p;
 }
 
 /*
 ** This routine is called on a collation sequence before it is used to
 ** check that it is defined. An undefined collation sequence exists when
 ** a database is loaded that contains references to collation sequences
 ** that have not been defined by sqlite3_create_collation() etc.
 **
 ** If required, this routine calls the 'collation needed' callback to
 ** request a definition of the collating sequence. If this doesn't work, 
 ** an equivalent collating sequence that uses a text encoding different
 ** from the main database is substituted, if one is available.
 */
 int sqlite3CheckCollSeq(Parse *pParse, CollSeq *pColl){
   if( pColl ){
     const char *zName = pColl->zName;
     sqlite3 *db = pParse->db;
-    CollSeq *p = sqlite3GetCollSeq(db, ENC(db), pColl, zName);
+    CollSeq *p = sqlite3GetCollSeq(pParse, ENC(db), pColl, zName);
     if( !p ){
-      sqlite3ErrorMsg(pParse, "no such collation sequence: %s", zName);
-      pParse->nErr++;
       return SQLITE_ERROR;
     }
     assert( p==pColl );
   }
   return SQLITE_OK;
 }
 
 
 
 /*
 ** Locate and return an entry from the db.aCollSeq hash table. If the entry
 ** specified by zName and nName is not found and parameter 'create' is
 ** true, then create a new entry. Otherwise return NULL.
 **
 ** Each pointer stored in the sqlite3.aCollSeq hash table contains an
 ** array of three CollSeq structures. The first is the collation sequence
-** prefferred for UTF-8, the second UTF-16le, and the third UTF-16be.
+** preferred for UTF-8, the second UTF-16le, and the third UTF-16be.
 **
 ** Stored immediately after the three collation sequences is a copy of
 ** the collation sequence name. A pointer to this string is stored in
 ** each collation sequence structure.
 */
 static CollSeq *findCollSeqEntry(
   sqlite3 *db,          /* Database connection */
   const char *zName,    /* Name of the collating sequence */
   int create            /* Create a new entry if true */
 ){
   CollSeq *pColl;
-  int nName = sqlite3Strlen30(zName);
-  pColl = sqlite3HashFind(&db->aCollSeq, zName, nName);
+  pColl = sqlite3HashFind(&db->aCollSeq, zName);
 
   if( 0==pColl && create ){
-    pColl = sqlite3DbMallocZero(db, 3*sizeof(*pColl) + nName + 1 );
+    int nName = sqlite3Strlen30(zName);
+    pColl = sqlite3DbMallocZero(db, 3*sizeof(*pColl) + nName + 1);
     if( pColl ){
       CollSeq *pDel = 0;
       pColl[0].zName = (char*)&pColl[3];
       pColl[0].enc = SQLITE_UTF8;
       pColl[1].zName = (char*)&pColl[3];
       pColl[1].enc = SQLITE_UTF16LE;
       pColl[2].zName = (char*)&pColl[3];
       pColl[2].enc = SQLITE_UTF16BE;
       memcpy(pColl[0].zName, zName, nName);
       pColl[0].zName[nName] = 0;
-      pDel = sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, nName, pColl);
+      pDel = sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, pColl);
 
       /* If a malloc() failure occurred in sqlite3HashInsert(), it will 
       ** return the pColl pointer to be deleted (because it wasn't added
       ** to the hash table).
       */
       assert( pDel==0 || pDel==pColl );
       if( pDel!=0 ){
         db->mallocFailed = 1;
         sqlite3DbFree(db, pDel);
         pColl = 0;
@@ skipping 35 matching lines @@
   if( pColl ) pColl += enc-1;
   return pColl;
 }
 
 /* During the search for the best function definition, this procedure
 ** is called to test how well the function passed as the first argument
 ** matches the request for a function with nArg arguments in a system
 ** that uses encoding enc. The value returned indicates how well the
 ** request is matched. A higher value indicates a better match.
 **
+** If nArg is -1 that means to only return a match (non-zero) if p->nArg
+** is also -1.  In other words, we are searching for a function that
+** takes a variable number of arguments.
+**
+** If nArg is -2 that means that we are searching for any function 
+** regardless of the number of arguments it uses, so return a positive
+** match score for any
+**
 ** The returned value is always between 0 and 6, as follows:
 **
-** 0: Not a match, or if nArg<0 and the function is has no implementation.
-** 1: A variable arguments function that prefers UTF-8 when a UTF-16
-**    encoding is requested, or vice versa.
-** 2: A variable arguments function that uses UTF-16BE when UTF-16LE is
-**    requested, or vice versa.
-** 3: A variable arguments function using the same text encoding.
-** 4: A function with the exact number of arguments requested that
-**    prefers UTF-8 when a UTF-16 encoding is requested, or vice versa.
-** 5: A function with the exact number of arguments requested that
-**    prefers UTF-16LE when UTF-16BE is requested, or vice versa.
-** 6: An exact match.
+** 0: Not a match.
+** 1: UTF8/16 conversion required and function takes any number of arguments.
+** 2: UTF16 byte order change required and function takes any number of args.
+** 3: encoding matches and function takes any number of arguments
+** 4: UTF8/16 conversion required - argument count matches exactly
+** 5: UTF16 byte order conversion required - argument count matches exactly
+** 6: Perfect match:  encoding and argument count match exactly.
 **
+** If nArg==(-2) then any function with a non-null xStep or xFunc is
+** a perfect match and any function with both xStep and xFunc NULL is
+** a non-match.
 */
-static int matchQuality(FuncDef *p, int nArg, u8 enc){
-  int match = 0;
-  if( p->nArg==-1 || p->nArg==nArg 
-   || (nArg==-1 && (p->xFunc!=0 || p->xStep!=0))
-  ){
+#define FUNC_PERFECT_MATCH 6  /* The score for a perfect match */
+static int matchQuality(
+  FuncDef *p,     /* The function we are evaluating for match quality */
+  int nArg,       /* Desired number of arguments.  (-1)==any */
+  u8 enc          /* Desired text encoding */
+){
+  int match;
+
+  /* nArg of -2 is a special case */
+  if( nArg==(-2) ) return (p->xFunc==0 && p->xStep==0) ? 0 : FUNC_PERFECT_MATCH;
+
+  /* Wrong number of arguments means "no match" */
+  if( p->nArg!=nArg && p->nArg>=0 ) return 0;
+
+  /* Give a better score to a function with a specific number of arguments
+  ** than to function that accepts any number of arguments. */
+  if( p->nArg==nArg ){
+    match = 4;
+  }else{
     match = 1;
-    if( p->nArg==nArg || nArg==-1 ){
-      match = 4;
-    }
-    if( enc==p->iPrefEnc ){
-      match += 2;
-    }
-    else if( (enc==SQLITE_UTF16LE && p->iPrefEnc==SQLITE_UTF16BE) ||
-             (enc==SQLITE_UTF16BE && p->iPrefEnc==SQLITE_UTF16LE) ){
-      match += 1;
-    }
   }
+
+  /* Bonus points if the text encoding matches */
+  if( enc==(p->funcFlags & SQLITE_FUNC_ENCMASK) ){
+    match += 2;  /* Exact encoding match */
+  }else if( (enc & p->funcFlags & 2)!=0 ){
+    match += 1;  /* Both are UTF16, but with different byte orders */
+  }
+
   return match;
 }
 
 /*
 ** Search a FuncDefHash for a function with the given name.  Return
 ** a pointer to the matching FuncDef if found, or 0 if there is no match.
 */
 static FuncDef *functionSearch(
   FuncDefHash *pHash,  /* Hash table to search */
   int h,               /* Hash of the name */
@@ skipping 35 matching lines @@
   
 
 /*
 ** Locate a user function given a name, a number of arguments and a flag
 ** indicating whether the function prefers UTF-16 over UTF-8.  Return a
 ** pointer to the FuncDef structure that defines that function, or return
 ** NULL if the function does not exist.
 **
 ** If the createFlag argument is true, then a new (blank) FuncDef
 ** structure is created and liked into the "db" structure if a
-** no matching function previously existed.  When createFlag is true
-** and the nArg parameter is -1, then only a function that accepts
-** any number of arguments will be returned.
+** no matching function previously existed.
 **
-** If createFlag is false and nArg is -1, then the first valid
-** function found is returned.  A function is valid if either xFunc
-** or xStep is non-zero.
+** If nArg is -2, then the first valid function found is returned.  A
+** function is valid if either xFunc or xStep is non-zero.  The nArg==(-2)
+** case is used to see if zName is a valid function name for some number
+** of arguments.  If nArg is -2, then createFlag must be 0.
 **
 ** If createFlag is false, then a function with the required name and
 ** number of arguments may be returned even if the eTextRep flag does not
 ** match that requested.
 */
 FuncDef *sqlite3FindFunction(
   sqlite3 *db,       /* An open database */
   const char *zName, /* Name of the function.  Not null-terminated */
   int nName,         /* Number of characters in the name */
   int nArg,          /* Number of arguments.  -1 means any number */
   u8 enc,            /* Preferred text encoding */
-  int createFlag     /* Create new entry if true and does not otherwise exist */
+  u8 createFlag      /* Create new entry if true and does not otherwise exist */
 ){
   FuncDef *p;         /* Iterator variable */
   FuncDef *pBest = 0; /* Best match found so far */
   int bestScore = 0;  /* Score of best match */
   int h;              /* Hash value */
 
-
-  assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
+  assert( nArg>=(-2) );
+  assert( nArg>=(-1) || createFlag==0 );
   h = (sqlite3UpperToLower[(u8)zName[0]] + nName) % ArraySize(db->aFunc.a);
 
   /* First search for a match amongst the application-defined functions.
   */
   p = functionSearch(&db->aFunc, h, zName, nName);
   while( p ){
     int score = matchQuality(p, nArg, enc);
     if( score>bestScore ){
       pBest = p;
       bestScore = score;
@@ skipping 24 matching lines @@
         bestScore = score;
       }
       p = p->pNext;
     }
   }
 
   /* If the createFlag parameter is true and the search did not reveal an
   ** exact match for the name, number of arguments and encoding, then add a
   ** new entry to the hash table and return it.
   */
-  if( createFlag && (bestScore<6 || pBest->nArg!=nArg) && 
+  if( createFlag && bestScore<FUNC_PERFECT_MATCH && 
       (pBest = sqlite3DbMallocZero(db, sizeof(*pBest)+nName+1))!=0 ){
     pBest->zName = (char *)&pBest[1];
     pBest->nArg = (u16)nArg;
-    pBest->iPrefEnc = enc;
+    pBest->funcFlags = enc;
     memcpy(pBest->zName, zName, nName);
     pBest->zName[nName] = 0;
     sqlite3FuncDefInsert(&db->aFunc, pBest);
   }
 
   if( pBest && (pBest->xStep || pBest->xFunc || createFlag) ){
     return pBest;
   }
   return 0;
 }
@@ skipping 21 matching lines @@
   }
   sqlite3HashClear(&temp2);
   sqlite3HashInit(&pSchema->tblHash);
   for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){
     Table *pTab = sqliteHashData(pElem);
     sqlite3DeleteTable(0, pTab);
   }
   sqlite3HashClear(&temp1);
   sqlite3HashClear(&pSchema->fkeyHash);
   pSchema->pSeqTab = 0;
-  if( pSchema->flags & DB_SchemaLoaded ){
+  if( pSchema->schemaFlags & DB_SchemaLoaded ){
     pSchema->iGeneration++;
-    pSchema->flags &= ~DB_SchemaLoaded;
+    pSchema->schemaFlags &= ~DB_SchemaLoaded;
   }
 }
 
 /*
 ** Find and return the schema associated with a BTree.  Create
 ** a new one if necessary.
 */
 Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){
   Schema * p;
   if( pBt ){
     p = (Schema *)sqlite3BtreeSchema(pBt, sizeof(Schema), sqlite3SchemaClear);
   }else{
     p = (Schema *)sqlite3DbMallocZero(0, sizeof(Schema));
   }
   if( !p ){
     db->mallocFailed = 1;
   }else if ( 0==p->file_format ){
     sqlite3HashInit(&p->tblHash);
     sqlite3HashInit(&p->idxHash);
     sqlite3HashInit(&p->trigHash);
     sqlite3HashInit(&p->fkeyHash);
     p->enc = SQLITE_UTF8;
   }
   return p;
 }