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Overview
| Comment: | Avoid unnecessary Mem initializations when generating a new sqlite3_stmt object. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: | 47ae1cda8dc255d100aeb8cb90ea4c9e |
| User & Date: | drh 2016-09-30 17:46:44 |
Context
|
2016-09-30
| ||
| 18:35 | Remove unnecessary fields from the Parse object. check-in: 814e41da user: drh tags: trunk | |
| 17:46 | Avoid unnecessary Mem initializations when generating a new sqlite3_stmt object. check-in: 47ae1cda user: drh tags: trunk | |
|
2016-09-29
| ||
| 20:28 | Small size and performance optimization to sqlite3VdbeChangeP5(). check-in: 3c93c8f5 user: drh tags: trunk | |
Changes
Changes to src/vdbe.c.
1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 |
case OP_Null: { /* out2 */
int cnt;
u16 nullFlag;
pOut = out2Prerelease(p, pOp);
cnt = pOp->p3-pOp->p2;
assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
pOut->flags = nullFlag = pOp->p1 ? (MEM_Null|MEM_Cleared) : MEM_Null;
while( cnt>0 ){
pOut++;
memAboutToChange(p, pOut);
sqlite3VdbeMemSetNull(pOut);
pOut->flags = nullFlag;
cnt--;
}
break;
}
/* Opcode: SoftNull P1 * * * *
** Synopsis: r[P1]=NULL
|
> > |
1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 |
case OP_Null: { /* out2 */
int cnt;
u16 nullFlag;
pOut = out2Prerelease(p, pOp);
cnt = pOp->p3-pOp->p2;
assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
pOut->flags = nullFlag = pOp->p1 ? (MEM_Null|MEM_Cleared) : MEM_Null;
pOut->n = 0;
while( cnt>0 ){
pOut++;
memAboutToChange(p, pOut);
sqlite3VdbeMemSetNull(pOut);
pOut->flags = nullFlag;
pOut->n = 0;
cnt--;
}
break;
}
/* Opcode: SoftNull P1 * * * *
** Synopsis: r[P1]=NULL
|
Changes to src/vdbeaux.c.
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fprintf(pOut, zFormat1, pc,
sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5,
zCom
);
fflush(pOut);
}
#endif
/*
** Release an array of N Mem elements
*/
static void releaseMemArray(Mem *p, int N){
if( p && N ){
Mem *pEnd = &p[N];
................................................................................
if( sqlite3VdbeMemClearAndResize(pMem, 100) ){ /* P4 */
assert( p->db->mallocFailed );
return SQLITE_ERROR;
}
pMem->flags = MEM_Str|MEM_Term;
zP4 = displayP4(pOp, pMem->z, pMem->szMalloc);
if( zP4!=pMem->z ){
sqlite3VdbeMemSetStr(pMem, zP4, -1, SQLITE_UTF8, 0);
}else{
assert( pMem->z!=0 );
pMem->n = sqlite3Strlen30(pMem->z);
pMem->enc = SQLITE_UTF8;
}
pMem++;
................................................................................
** of the prepared statement.
*/
n = ROUND8(sizeof(Op)*p->nOp); /* Bytes of opcode memory used */
x.pSpace = &((u8*)p->aOp)[n]; /* Unused opcode memory */
assert( EIGHT_BYTE_ALIGNMENT(x.pSpace) );
x.nFree = ROUNDDOWN8(pParse->szOpAlloc - n); /* Bytes of unused memory */
assert( x.nFree>=0 );
if( x.nFree>0 ){
memset(x.pSpace, 0, x.nFree);
assert( EIGHT_BYTE_ALIGNMENT(&x.pSpace[x.nFree]) );
}
resolveP2Values(p, &nArg);
p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);
if( pParse->explain && nMem<10 ){
nMem = 10;
}
p->expired = 0;
................................................................................
p->aVar = allocSpace(&x, p->aVar, nVar*sizeof(Mem));
p->apArg = allocSpace(&x, p->apArg, nArg*sizeof(Mem*));
p->apCsr = allocSpace(&x, p->apCsr, nCursor*sizeof(VdbeCursor*));
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
p->anExec = allocSpace(&x, p->anExec, p->nOp*sizeof(i64));
#endif
if( x.nNeeded==0 ) break;
x.pSpace = p->pFree = sqlite3DbMallocZero(db, x.nNeeded);
x.nFree = x.nNeeded;
}while( !db->mallocFailed );
p->nCursor = nCursor;
if( p->aVar ){
p->nVar = (ynVar)nVar;
for(n=0; n<nVar; n++){
p->aVar[n].flags = MEM_Null;
p->aVar[n].db = db;
}
}
p->nzVar = pParse->nzVar;
p->azVar = pParse->azVar;
pParse->nzVar = 0;
pParse->azVar = 0;
if( p->aMem ){
p->nMem = nMem;
for(n=0; n<nMem; n++){
p->aMem[n].flags = MEM_Undefined;
p->aMem[n].db = db;
}
}
p->explain = pParse->explain;
sqlite3VdbeRewind(p);
}
/*
** Close a VDBE cursor and release all the resources that cursor
** happens to hold.
*/
................................................................................
int n;
sqlite3 *db = p->db;
releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
sqlite3DbFree(db, p->aColName);
n = nResColumn*COLNAME_N;
p->nResColumn = (u16)nResColumn;
p->aColName = pColName = (Mem*)sqlite3DbMallocZero(db, sizeof(Mem)*n );
if( p->aColName==0 ) return;
while( n-- > 0 ){
pColName->flags = MEM_Null;
pColName->db = p->db;
pColName++;
}
}
/*
** Set the name of the idx'th column to be returned by the SQL statement.
** zName must be a pointer to a nul terminated string.
**
** This call must be made after a call to sqlite3VdbeSetNumCols().
|
> > > > > > > > > > > > > > > > < < | < | < < < < < < < < | > > > > < < < > > > > > > | < < | | < < < < |
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fprintf(pOut, zFormat1, pc,
sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5,
zCom
);
fflush(pOut);
}
#endif
/*
** Initialize an array of N Mem element.
*/
static void initMemArray(Mem *p, int N, sqlite3 *db, u16 flags){
while( (N--)>0 ){
p->db = db;
p->flags = flags;
p->szMalloc = 0;
#ifdef SQLITE_DEBUG
p->pScopyFrom = 0;
#endif
p++;
}
}
/*
** Release an array of N Mem elements
*/
static void releaseMemArray(Mem *p, int N){
if( p && N ){
Mem *pEnd = &p[N];
................................................................................
if( sqlite3VdbeMemClearAndResize(pMem, 100) ){ /* P4 */
assert( p->db->mallocFailed );
return SQLITE_ERROR;
}
pMem->flags = MEM_Str|MEM_Term;
zP4 = displayP4(pOp, pMem->z, pMem->szMalloc);
if( zP4!=pMem->z ){
pMem->n = 0;
sqlite3VdbeMemSetStr(pMem, zP4, -1, SQLITE_UTF8, 0);
}else{
assert( pMem->z!=0 );
pMem->n = sqlite3Strlen30(pMem->z);
pMem->enc = SQLITE_UTF8;
}
pMem++;
................................................................................
** of the prepared statement.
*/
n = ROUND8(sizeof(Op)*p->nOp); /* Bytes of opcode memory used */
x.pSpace = &((u8*)p->aOp)[n]; /* Unused opcode memory */
assert( EIGHT_BYTE_ALIGNMENT(x.pSpace) );
x.nFree = ROUNDDOWN8(pParse->szOpAlloc - n); /* Bytes of unused memory */
assert( x.nFree>=0 );
assert( EIGHT_BYTE_ALIGNMENT(&x.pSpace[x.nFree]) );
resolveP2Values(p, &nArg);
p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);
if( pParse->explain && nMem<10 ){
nMem = 10;
}
p->expired = 0;
................................................................................
p->aVar = allocSpace(&x, p->aVar, nVar*sizeof(Mem));
p->apArg = allocSpace(&x, p->apArg, nArg*sizeof(Mem*));
p->apCsr = allocSpace(&x, p->apCsr, nCursor*sizeof(VdbeCursor*));
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
p->anExec = allocSpace(&x, p->anExec, p->nOp*sizeof(i64));
#endif
if( x.nNeeded==0 ) break;
x.pSpace = p->pFree = sqlite3DbMallocRawNN(db, x.nNeeded);
x.nFree = x.nNeeded;
}while( !db->mallocFailed );
p->nzVar = pParse->nzVar;
p->azVar = pParse->azVar;
pParse->nzVar = 0;
pParse->azVar = 0;
p->explain = pParse->explain;
if( db->mallocFailed==0 ){
p->nCursor = nCursor;
p->nVar = (ynVar)nVar;
initMemArray(p->aVar, nVar, db, MEM_Null);
p->nMem = nMem;
initMemArray(p->aMem, nMem, db, MEM_Undefined);
memset(p->apArg, 0, nArg*sizeof(Mem*));
memset(p->apCsr, 0, nCursor*sizeof(VdbeCursor*));
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
memset(p->anExec, 0, p->nOp*sizeof(i64));
#endif
}
sqlite3VdbeRewind(p);
}
/*
** Close a VDBE cursor and release all the resources that cursor
** happens to hold.
*/
................................................................................
int n;
sqlite3 *db = p->db;
releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
sqlite3DbFree(db, p->aColName);
n = nResColumn*COLNAME_N;
p->nResColumn = (u16)nResColumn;
p->aColName = pColName = (Mem*)sqlite3DbMallocRawNN(db, sizeof(Mem)*n );
if( p->aColName==0 ) return;
initMemArray(p->aColName, n, p->db, MEM_Null);
}
/*
** Set the name of the idx'th column to be returned by the SQL statement.
** zName must be a pointer to a nul terminated string.
**
** This call must be made after a call to sqlite3VdbeSetNumCols().
|
Changes to src/vdbemem.c.
289 290 291 292 293 294 295 296 297 298 299 300 301 302 |
assert( !(fg&(MEM_Str|MEM_Blob)) );
assert( fg&(MEM_Int|MEM_Real) );
assert( (pMem->flags&MEM_RowSet)==0 );
assert( EIGHT_BYTE_ALIGNMENT(pMem) );
if( sqlite3VdbeMemClearAndResize(pMem, nByte) ){
return SQLITE_NOMEM_BKPT;
}
/* For a Real or Integer, use sqlite3_snprintf() to produce the UTF-8
** string representation of the value. Then, if the required encoding
** is UTF-16le or UTF-16be do a translation.
**
|
> |
289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 |
assert( !(fg&(MEM_Str|MEM_Blob)) );
assert( fg&(MEM_Int|MEM_Real) );
assert( (pMem->flags&MEM_RowSet)==0 );
assert( EIGHT_BYTE_ALIGNMENT(pMem) );
if( sqlite3VdbeMemClearAndResize(pMem, nByte) ){
pMem->enc = 0;
return SQLITE_NOMEM_BKPT;
}
/* For a Real or Integer, use sqlite3_snprintf() to produce the UTF-8
** string representation of the value. Then, if the required encoding
** is UTF-16le or UTF-16be do a translation.
**
|