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Performance optimization on the Column opcode. 

FossilOrigin-Name: ecc98bef43c2fd07d64e4efddf340929a875ebac
This commit is contained in:
drh 2016-01-11 18:05:00 +00:00
parent 50922cfc7c
commit 69f6e2587b
3 changed files with 35 additions and 33 deletions
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12
manifest
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@ -1,5 +1,5 @@
C Performance\soptimization\sin\ssqlite3WalkExpr().
D 2016-01-11T14:19:14.339
C Performance\soptimization\son\sthe\sColumn\sopcode.
D 2016-01-11T18:05:00.482
F Makefile.in 7c8cc4c2f0179efc6fa9492141d1fb65f4807054
F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
F Makefile.msc e45d8b9b56dfa3f2cd860b2c28bd9d304513b042
@ -398,7 +398,7 @@ F src/update.c 17332f9fe818cbc0444c36a811800af8498af4c3
F src/utf.c 32d7f82aa921322f3e1c956f4b58f019ebd2c6b3
F src/util.c e802e8e311a0d6c48cd1b3e89db164f6f0248d70
F src/vacuum.c 2ddd5cad2a7b9cef7f9e431b8c7771634c6b1701
F src/vdbe.c 6ac8e5d808d48afc369316e147c191102f0584c1
F src/vdbe.c 6572d00eefeaa0b14b325fdf3a409920ec3fee82
F src/vdbe.h efb7a8c1459e31f3ea4377824c6a7e4cb5068637
F src/vdbeInt.h 42eefa4f9e7432b9968d321b44e48821ec13b189
F src/vdbeapi.c 020681b943e77766b32ae1cddf86d7831b7374ca
@ -1407,7 +1407,7 @@ F tool/vdbe_profile.tcl 246d0da094856d72d2c12efec03250d71639d19f
F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
P 8e807bfaa197027d0cb73532baa96755ce71ea12
R 177e5551beb5399a29df920e18a04961
P 2f8bd5fab8cc51d1f8932c3490fd24dbccf6ef31
R 68508ce4367c0efdf38feafa98972c4a
U drh
Z b8d12fcc18213355136dacd10d5cf924
Z e90441a49428aea3c83069305613bb8e

2
manifest.uuid
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@ -1 +1 @@
2f8bd5fab8cc51d1f8932c3490fd24dbccf6ef31
ecc98bef43c2fd07d64e4efddf340929a875ebac

54
src/vdbe.c
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@ -2374,7 +2374,6 @@ case OP_Column: {
u64 offset64; /* 64-bit offset */
u32 avail; /* Number of bytes of available data */
u32 t; /* A type code from the record header */
u16 fx; /* pDest->flags value */
Mem *pReg; /* PseudoTable input register */
p2 = pOp->p2;
@ -2552,10 +2551,31 @@ case OP_Column: {
assert( sqlite3VdbeCheckMemInvariants(pDest) );
if( VdbeMemDynamic(pDest) ) sqlite3VdbeMemSetNull(pDest);
assert( t==pC->aType[p2] );
pDest->enc = encoding;
if( pC->szRow>=aOffset[p2+1] ){
/* This is the common case where the desired content fits on the original
** page - where the content is not on an overflow page */
sqlite3VdbeSerialGet(pC->aRow+aOffset[p2], t, pDest);
zData = pC->aRow + aOffset[p2];
if( t<12 ){
sqlite3VdbeSerialGet(zData, t, pDest);
}else{
/* If the column value is a string, we need a persistent value, not
** a MEM_Ephem value. This branch is a fast short-cut that is equivalent
** to calling sqlite3VdbeSerialGet() and sqlite3VdbeDeephemeralize().
*/
static const u16 aFlag[] = { MEM_Blob, MEM_Str|MEM_Term };
pDest->n = len = (t-12)/2;
if( pDest->szMalloc < len+2 ){
pDest->flags = MEM_Null;
if( sqlite3VdbeMemGrow(pDest, len+2, 0) ) goto no_mem;
}else{
pDest->z = pDest->zMalloc;
}
memcpy(pDest->z, zData, len);
pDest->z[len] = 0;
pDest->z[len+1] = 0;
pDest->flags = aFlag[t&1];
}
}else{
/* This branch happens only when content is on overflow pages */
if( ((pOp->p5 & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG))!=0
@ -2567,38 +2587,20 @@ case OP_Column: {
** 2. the length(X) function if X is a blob, and
** 3. if the content length is zero.
** So we might as well use bogus content rather than reading
** content from disk. NULL will work for the value for strings
** and blobs and whatever is in the payloadSize64 variable
** will work for everything else. */
sqlite3VdbeSerialGet(t<=13 ? (u8*)&payloadSize64 : 0, t, pDest);
** content from disk. */
static u8 aZero[8]; /* This is the bogus content */
sqlite3VdbeSerialGet(aZero, t, pDest);
}else{
rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, !pC->isTable,
pDest);
if( rc!=SQLITE_OK ){
goto op_column_error;
if( rc==SQLITE_OK ){
sqlite3VdbeSerialGet((const u8*)pDest->z, t, pDest);
pDest->flags &= ~MEM_Ephem;
}
sqlite3VdbeSerialGet((const u8*)pDest->z, t, pDest);
pDest->flags &= ~MEM_Ephem;
}
}
pDest->enc = encoding;
op_column_out:
/* If the column value is an ephemeral string, go ahead and persist
** that string in case the cursor moves before the column value is
** used. The following code does the equivalent of Deephemeralize()
** but does it faster. */
if( (pDest->flags & MEM_Ephem)!=0 && pDest->z ){
fx = pDest->flags & (MEM_Str|MEM_Blob);
assert( fx!=0 );
zData = (const u8*)pDest->z;
len = pDest->n;
if( sqlite3VdbeMemClearAndResize(pDest, len+2) ) goto no_mem;
memcpy(pDest->z, zData, len);
pDest->z[len] = 0;
pDest->z[len+1] = 0;
pDest->flags = fx|MEM_Term;
}
op_column_error:
UPDATE_MAX_BLOBSIZE(pDest);
REGISTER_TRACE(pOp->p3, pDest);