Fix the Parse.aColCache column cache so that all of the valid entries are
in the first Parse.nColCache slots.
FossilOrigin-Name: 6028502059ccbd3699637b7a70a6d8ce1b7c3dad
diff --git a/src/expr.c b/src/expr.c
index e8c245e..0640029 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2964,32 +2964,19 @@
}
}
-#if defined(SQLITE_DEBUG)
/*
-** Verify the consistency of the column cache
+** Erase column-cache entry number i
*/
-static int cacheIsValid(Parse *pParse){
- int i, n;
- for(i=n=0; i<SQLITE_N_COLCACHE; i++){
- if( pParse->aColCache[i].iReg>0 ) n++;
- }
- return n==pParse->nColCache;
-}
-#endif
-
-/*
-** Clear a cache entry.
-*/
-static void cacheEntryClear(Parse *pParse, struct yColCache *p){
- if( p->tempReg ){
+static void cacheEntryClear(Parse *pParse, int i){
+ if( pParse->aColCache[i].tempReg ){
if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){
- pParse->aTempReg[pParse->nTempReg++] = p->iReg;
+ pParse->aTempReg[pParse->nTempReg++] = pParse->aColCache[i].iReg;
}
- p->tempReg = 0;
}
- p->iReg = 0;
pParse->nColCache--;
- assert( pParse->db->mallocFailed || cacheIsValid(pParse) );
+ if( i<pParse->nColCache ){
+ pParse->aColCache[i] = pParse->aColCache[pParse->nColCache];
+ }
}
@@ -3019,46 +3006,33 @@
** that the object will never already be in cache. Verify this guarantee.
*/
#ifndef NDEBUG
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- assert( p->iReg==0 || p->iTable!=iTab || p->iColumn!=iCol );
+ for(i=0, p=pParse->aColCache; i<pParse->nColCache; i++, p++){
+ assert( p->iTable!=iTab || p->iColumn!=iCol );
}
#endif
- /* Find an empty slot and replace it */
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- if( p->iReg==0 ){
- p->iLevel = pParse->iCacheLevel;
- p->iTable = iTab;
- p->iColumn = iCol;
- p->iReg = iReg;
- p->tempReg = 0;
- p->lru = pParse->iCacheCnt++;
- pParse->nColCache++;
- assert( pParse->db->mallocFailed || cacheIsValid(pParse) );
- return;
+ /* If the cache is already full, delete the least recently used entry */
+ if( pParse->nColCache>=SQLITE_N_COLCACHE ){
+ minLru = 0x7fffffff;
+ idxLru = -1;
+ for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
+ if( p->lru<minLru ){
+ idxLru = i;
+ minLru = p->lru;
+ }
}
+ p = &pParse->aColCache[idxLru];
+ }else{
+ p = &pParse->aColCache[pParse->nColCache++];
}
- /* Replace the last recently used */
- minLru = 0x7fffffff;
- idxLru = -1;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- if( p->lru<minLru ){
- idxLru = i;
- minLru = p->lru;
- }
- }
- if( ALWAYS(idxLru>=0) ){
- p = &pParse->aColCache[idxLru];
- p->iLevel = pParse->iCacheLevel;
- p->iTable = iTab;
- p->iColumn = iCol;
- p->iReg = iReg;
- p->tempReg = 0;
- p->lru = pParse->iCacheCnt++;
- assert( cacheIsValid(pParse) );
- return;
- }
+ /* Add the new entry to the end of the cache */
+ p->iLevel = pParse->iCacheLevel;
+ p->iTable = iTab;
+ p->iColumn = iCol;
+ p->iReg = iReg;
+ p->tempReg = 0;
+ p->lru = pParse->iCacheCnt++;
}
/*
@@ -3066,13 +3040,14 @@
** Purge the range of registers from the column cache.
*/
void sqlite3ExprCacheRemove(Parse *pParse, int iReg, int nReg){
- struct yColCache *p;
- if( iReg<=0 || pParse->nColCache==0 ) return;
- p = &pParse->aColCache[SQLITE_N_COLCACHE-1];
- while(1){
- if( p->iReg >= iReg && p->iReg < iReg+nReg ) cacheEntryClear(pParse, p);
- if( p==pParse->aColCache ) break;
- p--;
+ int i = 0;
+ while( i<pParse->nColCache ){
+ struct yColCache *p = &pParse->aColCache[i];
+ if( p->iReg >= iReg && p->iReg < iReg+nReg ){
+ cacheEntryClear(pParse, i);
+ }else{
+ i++;
+ }
}
}
@@ -3096,8 +3071,7 @@
** the cache to the state it was in prior the most recent Push.
*/
void sqlite3ExprCachePop(Parse *pParse){
- int i;
- struct yColCache *p;
+ int i = 0;
assert( pParse->iCacheLevel>=1 );
pParse->iCacheLevel--;
#ifdef SQLITE_DEBUG
@@ -3105,9 +3079,11 @@
printf("POP to %d\n", pParse->iCacheLevel);
}
#endif
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- if( p->iReg && p->iLevel>pParse->iCacheLevel ){
- cacheEntryClear(pParse, p);
+ while( i<pParse->nColCache ){
+ if( pParse->aColCache[i].iLevel>pParse->iCacheLevel ){
+ cacheEntryClear(pParse, i);
+ }else{
+ i++;
}
}
}
@@ -3121,7 +3097,7 @@
static void sqlite3ExprCachePinRegister(Parse *pParse, int iReg){
int i;
struct yColCache *p;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
+ for(i=0, p=pParse->aColCache; i<pParse->nColCache; i++, p++){
if( p->iReg==iReg ){
p->tempReg = 0;
}
@@ -3199,7 +3175,7 @@
int i;
struct yColCache *p;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
+ for(i=0, p=pParse->aColCache; i<pParse->nColCache; i++, p++){
if( p->iReg>0 && p->iTable==iTable && p->iColumn==iColumn ){
p->lru = pParse->iCacheCnt++;
sqlite3ExprCachePinRegister(pParse, p->iReg);
@@ -3232,18 +3208,20 @@
*/
void sqlite3ExprCacheClear(Parse *pParse){
int i;
- struct yColCache *p;
#if SQLITE_DEBUG
if( pParse->db->flags & SQLITE_VdbeAddopTrace ){
printf("CLEAR\n");
}
#endif
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- if( p->iReg ){
- cacheEntryClear(pParse, p);
+ for(i=0; i<pParse->nColCache; i++){
+ if( pParse->aColCache[i].tempReg
+ && pParse->nTempReg<ArraySize(pParse->aTempReg)
+ ){
+ pParse->aTempReg[pParse->nTempReg++] = pParse->aColCache[i].iReg;
}
}
+ pParse->nColCache = 0;
}
/*
@@ -3275,7 +3253,7 @@
static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
int i;
struct yColCache *p;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
+ for(i=0, p=pParse->aColCache; i<pParse->nColCache; i++, p++){
int r = p->iReg;
if( r>=iFrom && r<=iTo ) return 1; /*NO_TEST*/
}
@@ -4971,7 +4949,7 @@
if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){
int i;
struct yColCache *p;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
+ for(i=0, p=pParse->aColCache; i<pParse->nColCache; i++, p++){
if( p->iReg==iReg ){
p->tempReg = 1;
return;