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Add the pcache module from the experimental branch. Also change things so that most of the built-in SQL functions are kept in single static hash-table, rather than creating and populating a separate hash table for each open database connection. (CVS 5566)

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FossilOrigin-Name: cb494e10d71852024647aaa254203579ad438ea9
This commit is contained in:
danielk1977
2008-08-20 14:49:23 +00:00
parent 2b300d5d6f
commit 8c0a791a58
29 changed files with 2204 additions and 1637 deletions
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92
src/callback.c
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@@ -13,7 +13,7 @@
** This file contains functions used to access the internal hash tables
** of user defined functions and collation sequences.
**
** $Id: callback.c,v 1.26 2008/07/28 19:34:53 drh Exp $
** $Id: callback.c,v 1.27 2008/08/20 14:49:24 danielk1977 Exp $
*/
#include "sqliteInt.h"
@@ -222,6 +222,44 @@ CollSeq *sqlite3FindCollSeq(
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.
**
** The returned value is always between 1 and 6, as follows:
**
** 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.
**
*/
static int matchQuality(FuncDef *p, int nArg, u8 enc){
int match = 0;
if( p->nArg==-1 || p->nArg==nArg || nArg==-1 ){
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;
}
}
return match;
}
/*
** 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
@@ -261,39 +299,26 @@ FuncDef *sqlite3FindFunction(
pFirst = (FuncDef*)sqlite3HashFind(&db->aFunc, zName, nName);
for(p=pFirst; p; p=p->pNext){
/* During the search for the best function definition, bestmatch is set
** as follows to indicate the quality of the match with the definition
** pointed to by pBest:
**
** 0: pBest is NULL. No match has been found.
** 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.
**
** A larger value of 'matchqual' indicates a more desirable match.
*/
if( p->nArg==-1 || p->nArg==nArg || nArg==-1 ){
int match = 1; /* Quality of this match */
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;
}
int match = matchQuality(p, nArg, enc);
if( match>bestmatch ){
pBest = p;
bestmatch = match;
}
}
/* If the createFlag parameter is false and no match was found amongst
** the custom functions stored in sqlite3.aFunc, try to find a built-in
** function to use.
*/
if( !createFlag && !pBest ){
FuncDef *aFunc;
int nFunc;
int i;
nFunc = sqlite3GetBuiltinFunction(zName, nName, &aFunc);
for(i=0; i<nFunc; i++){
int match = matchQuality(&aFunc[i], nArg, enc);
if( match>bestmatch ){
pBest = p;
pBest = &aFunc[i];
bestmatch = match;
}
}
@@ -304,7 +329,8 @@ FuncDef *sqlite3FindFunction(
** new entry to the hash table and return it.
*/
if( createFlag && bestmatch<6 &&
(pBest = sqlite3DbMallocZero(db, sizeof(*pBest)+nName))!=0 ){
(pBest = sqlite3DbMallocZero(db, sizeof(*pBest)+nName+1))!=0 ){
pBest->zName = (char *)&pBest[1];
pBest->nArg = nArg;
pBest->pNext = pFirst;
pBest->iPrefEnc = enc;