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Performance improvements for LIKE. It is still too slow though. (CVS 1535)

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FossilOrigin-Name: 30b81507fc404355751705c6f9856c178249eff1
This commit is contained in:
danielk1977
2004-06-06 12:41:49 +00:00
parent d02eb1fdf4
commit ad7dd42558
6 changed files with 77 additions and 38 deletions
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57
src/func.c
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@@ -16,7 +16,7 @@
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.63 2004/06/06 09:44:04 danielk1977 Exp $
** $Id: func.c,v 1.64 2004/06/06 12:41:50 danielk1977 Exp $
*/
#include <ctype.h>
#include <math.h>
@@ -418,7 +418,11 @@ LikePattern *compileLike(sqlite3_value *pPattern, u8 enc){
if( pc_state<0 ){
aState[n].failstate = -1;
}else if( pc_state==n ){
aState[n].failstate = pc_state;
if( c ){
aState[n].failstate = pc_state;
}else{
aState[n].failstate = -2;
}
}else{
int k = pLike->aState[n-1].failstate;
while( k>pc_state && aState[k+1].val!=-1 && aState[k+1].val!=c ){
@@ -461,13 +465,13 @@ static void likeFunc(
int argc,
sqlite3_value **argv
){
int s;
int c;
int nc;
register int c;
u8 enc;
int offset = 0;
const unsigned char *zString;
LikePattern *pLike = sqlite3_get_auxdata(context, 0);
struct LikeState *aState;
register struct LikeState *pState;
/* If either argument is NULL, the result is NULL */
if( sqlite3_value_type(argv[1])==SQLITE_NULL ||
@@ -479,6 +483,7 @@ static void likeFunc(
if( sqlite3_user_data(context) ){
enc = TEXT_Utf16;
zString = (const unsigned char *)sqlite3_value_text16(argv[1]);
assert(0);
}else{
enc = TEXT_Utf8;
zString = sqlite3_value_text(argv[1]);
@@ -493,33 +498,39 @@ static void likeFunc(
}
sqlite3_set_auxdata(context, 0, pLike, deleteLike);
}
aState = pLike->aState;
pState = aState;
s = 0;
nc = 1;
do {
int val = pLike->aState[s].val;
if( nc ) c = sqlite3ReadUniChar(zString, &offset, &enc, 1);
if( enc==TEXT_Utf8 ){
c = zString[offset++];
if( c&0x80 ){
offset--;
c = sqlite3ReadUniChar(zString, &offset, &enc, 1);
}
}else{
c = sqlite3ReadUniChar(zString, &offset, &enc, 1);
}
skip_read:
#if defined(TRACE_LIKE) && !defined(NDEBUG)
printf("State=%d:(%d, %d) Input=%d\n",
s, pLike->aState[s].val,
pLike->aState[s].failstate, c);
(aState - pState), pState->val, pState->failstate, c);
#endif
if( val==-1 || val==c ){
s++;
nc = 1;
if( pState->val==-1 || pState->val==c ){
pState++;
}else{
if( pLike->aState[s].failstate==s ){
nc = 1;
}else{
nc = 0;
s = pLike->aState[s].failstate;
struct LikeState *pFailState = &aState[pState->failstate];
if( pState!=pFailState ){
pState = pFailState;
if( c && pState>=aState ) goto skip_read;
}
}
}while( c && s>=0 );
}while( c && pState>=aState );
if( s==pLike->nState ){
if( (pState-aState)==pLike->nState || (pState-aState)<-1 ){
sqlite3_result_int(context, 1);
}else{
sqlite3_result_int(context, 0);
@@ -916,8 +927,8 @@ void sqlite3RegisterBuiltinFunctions(sqlite *db){
case 1: pArg = db; break;
case 2: pArg = (void *)(-1); break;
}
sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg, 0, 0,
pArg, aFuncs[i].xFunc, 0, 0);
sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg,
aFuncs[i].eTextRep, 0, pArg, aFuncs[i].xFunc, 0, 0);
}
for(i=0; i<sizeof(aAggs)/sizeof(aAggs[0]); i++){
void *pArg = 0;