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Enhance user function API to support association of meta-data with constant

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arguments and the specification of text encoding preference. The LIKE
operator takes advantage of both. (CVS 1534)

FossilOrigin-Name: 92337d8f79b9754cd61c73e7db2e792a1f482f50
This commit is contained in:
danielk1977
2004-06-06 09:44:03 +00:00
parent 51c6d9633f
commit d02eb1fdf4
12 changed files with 491 additions and 189 deletions
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103
src/expr.c
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@@ -12,7 +12,7 @@
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.134 2004/06/05 10:22:17 danielk1977 Exp $
** $Id: expr.c,v 1.135 2004/06/06 09:44:04 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -968,11 +968,12 @@ int sqlite3ExprCheck(Parse *pParse, Expr *pExpr, int allowAgg, int *pIsAgg){
int nId; /* Number of characters in function name */
const char *zId; /* The function name. */
FuncDef *pDef;
int iPrefEnc = (pParse->db->enc==TEXT_Utf8)?0:1;
getFunctionName(pExpr, &zId, &nId);
pDef = sqlite3FindFunction(pParse->db, zId, nId, n, 0);
pDef = sqlite3FindFunction(pParse->db, zId, nId, n, iPrefEnc, 0);
if( pDef==0 ){
pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, 0);
pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, iPrefEnc, 0);
if( pDef==0 ){
no_such_func = 1;
}else{
@@ -1233,12 +1234,15 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
const char *zId;
int p2 = 0;
int i;
int iPrefEnc = (pParse->db->enc==TEXT_Utf8)?0:1;
getFunctionName(pExpr, &zId, &nId);
pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, 0);
pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, iPrefEnc, 0);
assert( pDef!=0 );
nExpr = sqlite3ExprCodeExprList(pParse, pList);
for(i=0; i<nExpr && i<32; i++){
p2 &= (1<<i);
if( sqlite3ExprIsConstant(pList->a[i].pExpr) ){
p2 |= (1<<i);
}
}
sqlite3VdbeOp3(v, OP_Function, nExpr, p2, (char*)pDef, P3_FUNCDEF);
break;
@@ -1645,13 +1649,14 @@ int sqlite3ExprAnalyzeAggregates(Parse *pParse, Expr *pExpr){
}
}
if( i>=pParse->nAgg ){
int iPrefEnc = (pParse->db->enc==TEXT_Utf8)?0:1;
i = appendAggInfo(pParse);
if( i<0 ) return 1;
pParse->aAgg[i].isAgg = 1;
pParse->aAgg[i].pExpr = pExpr;
pParse->aAgg[i].pFunc = sqlite3FindFunction(pParse->db,
pExpr->token.z, pExpr->token.n,
pExpr->pList ? pExpr->pList->nExpr : 0, 0);
pExpr->pList ? pExpr->pList->nExpr : 0, iPrefEnc, 0);
}
pExpr->iAgg = i;
break;
@@ -1677,9 +1682,10 @@ int sqlite3ExprAnalyzeAggregates(Parse *pParse, Expr *pExpr){
}
/*
** Locate a user function given a name and a number of arguments.
** Return a pointer to the FuncDef structure that defines that
** function, or return NULL if the function does not exist.
** 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
@@ -1690,39 +1696,70 @@ int sqlite3ExprAnalyzeAggregates(Parse *pParse, Expr *pExpr){
** 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 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(
sqlite *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 */
int eTextRep, /* True to retrieve UTF-16 versions. */
int createFlag /* Create new entry if true and does not otherwise exist */
){
FuncDef *pFirst, *p, *pMaybe;
pFirst = p = (FuncDef*)sqlite3HashFind(&db->aFunc, zName, nName);
if( p && !createFlag && nArg<0 ){
while( p && p->xFunc==0 && p->xStep==0 ){ p = p->pNext; }
return p;
FuncDef *p; /* Iterator variable */
FuncDef *pFirst; /* First function with this name */
FuncDef *pBest = 0; /* Best match found so far */
int matchqual = 0;
/* Normalize argument values to simplify comparisons below. */
if( eTextRep ) eTextRep = 1;
if( nArg<-1 ) nArg = -1;
pFirst = (FuncDef*)sqlite3HashFind(&db->aFunc, zName, nName);
for(p=pFirst; p; p=p->pNext){
if( 1 || p->xFunc || p->xStep ){
if( p->nArg==nArg && p->iPrefEnc==eTextRep ){
/* A perfect match. */
pBest = p;
matchqual = 4;
break;
}
if( p->nArg==nArg ){
/* Number of arguments matches, but not the text encoding */
pBest = p;
matchqual = 3;
}
else if( (p->nArg<0) || (nArg<0) ){
if( matchqual<2 && p->iPrefEnc==eTextRep ){
/* Matched a varargs function with correct text encoding */
pBest = p;
matchqual = 2;
}
if( matchqual<1 ){
/* Matched a varargs function with incorrect text encoding */
pBest = p;
matchqual = 1;
}
}
}
}
pMaybe = 0;
while( p && p->nArg!=nArg ){
if( p->nArg<0 && !createFlag && (p->xFunc || p->xStep) ) pMaybe = p;
p = p->pNext;
if( createFlag && matchqual<4 &&
(pBest = sqliteMalloc(sizeof(*pBest)+nName+1)) ){
pBest->nArg = nArg;
pBest->pNext = pFirst;
pBest->zName = (char*)&pBest[1];
memcpy(pBest->zName, zName, nName);
pBest->zName[nName] = 0;
sqlite3HashInsert(&db->aFunc, pBest->zName, nName, (void*)pBest);
}
if( p && !createFlag && p->xFunc==0 && p->xStep==0 ){
return 0;
if( pBest && (pBest->xStep || pBest->xFunc || createFlag) ){
return pBest;
}
if( p==0 && pMaybe ){
assert( createFlag==0 );
return pMaybe;
}
if( p==0 && createFlag && (p = sqliteMalloc(sizeof(*p)+nName+1))!=0 ){
p->nArg = nArg;
p->pNext = pFirst;
p->zName = (char*)&p[1];
memcpy(p->zName, zName, nName);
p->zName[nName] = 0;
sqlite3HashInsert(&db->aFunc, p->zName, nName, (void*)p);
}
return p;
return 0;
}