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-rw-r--r--src/main.c22
-rw-r--r--src/malloc.c36
-rw-r--r--src/sqliteInt.h5
-rw-r--r--src/status.c13
4 files changed, 72 insertions, 4 deletions
diff --git a/src/main.c b/src/main.c
index 1afeee0bd..96234bfe4 100644
--- a/src/main.c
+++ b/src/main.c
@@ -683,6 +683,7 @@ int sqlite3_config(int op, ...){
static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
#ifndef SQLITE_OMIT_LOOKASIDE
void *pStart;
+ sqlite3_int64 szAlloc = sz*(sqlite3_int64)cnt;
if( sqlite3LookasideUsed(db,0)>0 ){
return SQLITE_BUSY;
@@ -705,7 +706,7 @@ static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
pStart = 0;
}else if( pBuf==0 ){
sqlite3BeginBenignMalloc();
- pStart = sqlite3Malloc( sz*(sqlite3_int64)cnt ); /* IMP: R-61949-35727 */
+ pStart = sqlite3Malloc( szAlloc ); /* IMP: R-61949-35727 */
sqlite3EndBenignMalloc();
if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
}else{
@@ -714,6 +715,15 @@ static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
db->lookaside.pStart = pStart;
db->lookaside.pInit = 0;
db->lookaside.pFree = 0;
+#ifndef SQLITE_OMIT_MINI_LOOKASIDE
+ db->lookaside.pMiniInit = 0;
+ db->lookaside.pMiniFree = 0;
+ /* The arithmetic below causes the number of large lookaside slots to be 1/3
+ ** the number of mini slots, based on the observation that 75% of allocations
+ ** are <=128B.
+ */
+ cnt = szAlloc/(3*128+sz);
+#endif
db->lookaside.sz = (u16)sz;
db->lookaside.szTrue = (u16)sz;
if( pStart ){
@@ -727,6 +737,16 @@ static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
db->lookaside.pInit = p;
p = (LookasideSlot*)&((u8*)p)[sz];
}
+#ifndef SQLITE_OMIT_MINI_LOOKASIDE
+ db->lookaside.pMiddle = p;
+ /* Fill the remainder of the buffer with mini slots */
+ while(p<=(LookasideSlot*)&((u8*)pStart)[szAlloc-128]){
+ p->pNext = db->lookaside.pMiniInit;
+ db->lookaside.pMiniInit = p;
+ db->lookaside.nSlot++;
+ p = (LookasideSlot*)&((u8*)p)[128];
+ }
+#endif
db->lookaside.pEnd = p;
db->lookaside.bDisable = 0;
db->lookaside.bMalloced = pBuf==0 ?1:0;
diff --git a/src/malloc.c b/src/malloc.c
index 131ed6039..9241b97c7 100644
--- a/src/malloc.c
+++ b/src/malloc.c
@@ -332,6 +332,13 @@ int sqlite3MallocSize(void *p){
assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
return sqlite3GlobalConfig.m.xSize(p);
}
+static int lookasideMallocSize(sqlite3 *db, void *p){
+#ifndef SQLITE_OMIT_MINI_LOOKASIDE
+ return p<db->lookaside.pMiddle ? db->lookaside.szTrue : 128;
+#else
+ return db->lookaside.szTrue;
+#endif
+}
int sqlite3DbMallocSize(sqlite3 *db, void *p){
assert( p!=0 );
if( db==0 || !isLookaside(db,p) ){
@@ -347,7 +354,7 @@ int sqlite3DbMallocSize(sqlite3 *db, void *p){
return sqlite3GlobalConfig.m.xSize(p);
}else{
assert( sqlite3_mutex_held(db->mutex) );
- return db->lookaside.szTrue;
+ return lookasideMallocSize(db, p);
}
}
sqlite3_uint64 sqlite3_msize(void *p){
@@ -397,6 +404,17 @@ void sqlite3DbFreeNN(sqlite3 *db, void *p){
}
if( isLookaside(db, p) ){
LookasideSlot *pBuf = (LookasideSlot*)p;
+#ifndef SQLITE_OMIT_MINI_LOOKASIDE
+ if( p>=db->lookaside.pMiddle ){
+# ifdef SQLITE_DEBUG
+ /* Trash all content in the buffer being freed */
+ memset(p, 0xaa, 128);
+# endif
+ pBuf->pNext = db->lookaside.pMiniFree;
+ db->lookaside.pMiniFree = pBuf;
+ return;
+ }
+#endif
#ifdef SQLITE_DEBUG
/* Trash all content in the buffer being freed */
memset(p, 0xaa, db->lookaside.szTrue);
@@ -564,6 +582,18 @@ void *sqlite3DbMallocRawNN(sqlite3 *db, u64 n){
return db->mallocFailed ? 0 : dbMallocRawFinish(db, n);
}
db->lookaside.anStat[1]++;
+# ifndef SQLITE_OMIT_MINI_LOOKASIDE
+ }else if( n<=128 ){
+ if( (pBuf = db->lookaside.pMiniFree)!=0 ){
+ db->lookaside.pMiniFree = pBuf->pNext;
+ db->lookaside.anStat[0]++;
+ return (void*)pBuf;
+ }else if( (pBuf = db->lookaside.pMiniInit)!=0 ){
+ db->lookaside.pMiniInit = pBuf->pNext;
+ db->lookaside.anStat[0]++;
+ return (void*)pBuf;
+ }
+# endif
}else if( (pBuf = db->lookaside.pFree)!=0 ){
db->lookaside.pFree = pBuf->pNext;
db->lookaside.anStat[0]++;
@@ -597,7 +627,7 @@ void *sqlite3DbRealloc(sqlite3 *db, void *p, u64 n){
assert( db!=0 );
if( p==0 ) return sqlite3DbMallocRawNN(db, n);
assert( sqlite3_mutex_held(db->mutex) );
- if( isLookaside(db,p) && n<=db->lookaside.szTrue ) return p;
+ if( isLookaside(db,p) && n<lookasideMallocSize(db, p) ) return p;
return dbReallocFinish(db, p, n);
}
static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n){
@@ -608,7 +638,7 @@ static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n){
if( isLookaside(db, p) ){
pNew = sqlite3DbMallocRawNN(db, n);
if( pNew ){
- memcpy(pNew, p, db->lookaside.szTrue);
+ memcpy(pNew, p, lookasideMallocSize(db, p));
sqlite3DbFree(db, p);
}
}else{
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 2aca2abfa..528092337 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1287,6 +1287,11 @@ struct Lookaside {
u32 anStat[3]; /* 0: hits. 1: size misses. 2: full misses */
LookasideSlot *pInit; /* List of buffers not previously used */
LookasideSlot *pFree; /* List of available buffers */
+#ifndef SQLITE_OMIT_MINI_LOOKASIDE
+ LookasideSlot *pMiniInit; /* List of mini buffers not prediously used */
+ LookasideSlot *pMiniFree; /* List of available mini buffers */
+ void *pMiddle; /* An address between the fullsize and mini buffers */
+#endif
void *pStart; /* First byte of available memory space */
void *pEnd; /* First byte past end of available space */
};
diff --git a/src/status.c b/src/status.c
index a5a39f4c1..d7ffe99ed 100644
--- a/src/status.c
+++ b/src/status.c
@@ -188,6 +188,10 @@ static u32 countLookasideSlots(LookasideSlot *p){
int sqlite3LookasideUsed(sqlite3 *db, int *pHighwater){
u32 nInit = countLookasideSlots(db->lookaside.pInit);
u32 nFree = countLookasideSlots(db->lookaside.pFree);
+#ifndef SQLITE_OMIT_MINI_LOOKASIDE
+ nInit += countLookasideSlots(db->lookaside.pMiniInit);
+ nFree += countLookasideSlots(db->lookaside.pMiniFree);
+#endif
if( pHighwater ) *pHighwater = db->lookaside.nSlot - nInit;
return db->lookaside.nSlot - (nInit+nFree);
}
@@ -220,6 +224,15 @@ int sqlite3_db_status(
db->lookaside.pInit = db->lookaside.pFree;
db->lookaside.pFree = 0;
}
+#ifndef SQLITE_OMIT_MINI_LOOKASIDE
+ p = db->lookaside.pMiniFree;
+ if( p ){
+ while( p->pNext ) p = p->pNext;
+ p->pNext = db->lookaside.pMiniInit;
+ db->lookaside.pMiniInit = db->lookaside.pMiniFree;
+ db->lookaside.pMiniFree = 0;
+ }
+#endif
}
break;
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-19 14:31:13 +0000