From: drh Date: Sat, 16 Jan 2016 20:50:21 +0000 (+0000) Subject: Improvements to the way sqlite3VdbeAddOpList() works, resulting in a slightly X-Git-Tag: version-3.11.0~133 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2ce1865dd86b6a96e305e0736d719de7e60e7b46;p=thirdparty%2Fsqlite.git Improvements to the way sqlite3VdbeAddOpList() works, resulting in a slightly smaller and faster binary. FossilOrigin-Name: 88ceb588bcdb3ca86d0c58cfdeb61b5fe070872f --- diff --git a/manifest b/manifest index 8872e8fc50..c9a3b49a57 100644 --- a/manifest +++ b/manifest @@ -1,5 +1,5 @@ -C Add\sfurther\stests\sfor\sfts5.\sFix\ssome\sproblems\swith\sdetail=col\smode\sand\sauxiliary\sfunctions. -D 2016-01-16T18:58:51.767 +C Improvements\sto\sthe\sway\ssqlite3VdbeAddOpList()\sworks,\sresulting\sin\sa\sslightly\nsmaller\sand\sfaster\sbinary. +D 2016-01-16T20:50:21.742 F Makefile.in a476545d0c8626224d0bacac85c6e2967474af81 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434 F Makefile.msc 01e855f958932d0d3ed62ec675fc63e2cef61fcb @@ -336,7 +336,7 @@ F src/parse.y caad1e98edeca6960493d0c60d31b76820dd7776 F src/pcache.c 73895411fa6b7bd6f0091212feabbe833b358d23 F src/pcache.h 4d0ccaad264d360981ec5e6a2b596d6e85242545 F src/pcache1.c 72f644dc9e1468c72922eff5904048427b817051 -F src/pragma.c f3e7147299ca05ef4304a36f1fd6e002729c72c6 +F src/pragma.c 53c95f5454e2a8bdb25ebf1567bed6690910ce25 F src/pragma.h 64c78a648751b9f4f297276c4eb7507b14b4628c F src/prepare.c 74855ddbdfad6a1c4a4d5c4b0913ebb01174ba19 F src/printf.c af589a27b7d40f6f4f704e9eea99f02f18ad6d32 @@ -409,11 +409,11 @@ F src/utf.c 32d7f82aa921322f3e1c956f4b58f019ebd2c6b3 F src/util.c e802e8e311a0d6c48cd1b3e89db164f6f0248d70 F src/vacuum.c 2ddd5cad2a7b9cef7f9e431b8c7771634c6b1701 F src/vdbe.c b90d9d38e5e0260c2eafa3cb4c2274d8ea94da27 -F src/vdbe.h efb7a8c1459e31f3ea4377824c6a7e4cb5068637 +F src/vdbe.h 22f8c913bd2c8549b3d3a897da3428efbe944378 F src/vdbeInt.h 42eefa4f9e7432b9968d321b44e48821ec13b189 F src/vdbeapi.c ffae8f5af4570fbd548504e815e9fb7227f0822e -F src/vdbeaux.c 906c0350f316dd13a26d8a91865f1dd7f14dc19b -F src/vdbeblob.c fdc4a81605ae7a35ae94a55bd768b66d6be16f15 +F src/vdbeaux.c 82969fb2558e6cf57601e283f0101d0f60f5a4f2 +F src/vdbeblob.c 8542f282b58293bd61c2ea4b2125f250f4fc9543 F src/vdbemem.c b9181e77eca2a095929d46250daf85c8d2621fc0 F src/vdbesort.c 0971557e5d3c289e46f56a52aed2197c13251de7 F src/vdbetrace.c 8befe829faff6d9e6f6e4dee5a7d3f85cc85f1a0 @@ -1417,7 +1417,7 @@ F tool/vdbe_profile.tcl 246d0da094856d72d2c12efec03250d71639d19f F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f -P a4258cd4613c55acacb5c7b61faa3de7eb0759d2 -R 7d01724b879e1ef98656daadba5b9cfb -U dan -Z d745955e2f048d17831d9a126adffb23 +P de77d6026e8035c505a704e7b8cfe5af6579d35f +R e442832cd3e3e0853ec0a993c2468ee7 +U drh +Z 51b7d6e877f13b345892ef271baf2a12 diff --git a/manifest.uuid b/manifest.uuid index 94a16261bf..fda58e60e8 100644 --- a/manifest.uuid +++ b/manifest.uuid @@ -1 +1 @@ -de77d6026e8035c505a704e7b8cfe5af6579d35f \ No newline at end of file +88ceb588bcdb3ca86d0c58cfdeb61b5fe070872f \ No newline at end of file diff --git a/src/pragma.c b/src/pragma.c index 0d48057d21..50f7229c33 100644 --- a/src/pragma.c +++ b/src/pragma.c @@ -430,15 +430,17 @@ void sqlite3Pragma( { OP_Noop, 0, 0, 0}, { OP_ResultRow, 1, 1, 0}, }; - int addr; + VdbeOp *aOp; sqlite3VdbeUsesBtree(v, iDb); if( !zRight ){ setOneColumnName(v, "cache_size"); pParse->nMem += 2; - addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize,iLn); - sqlite3VdbeChangeP1(v, addr, iDb); - sqlite3VdbeChangeP1(v, addr+1, iDb); - sqlite3VdbeChangeP1(v, addr+6, SQLITE_DEFAULT_CACHE_SIZE); + sqlite3VdbeVerifyAvailableSpace(v, ArraySize(getCacheSize)); + aOp = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize, iLn); + assert( aOp!=0 ); + aOp[0].p1 = iDb; + aOp[1].p1 = iDb; + aOp[6].p1 = SQLITE_DEFAULT_CACHE_SIZE; }else{ int size = sqlite3AbsInt32(sqlite3Atoi(zRight)); sqlite3BeginWriteOperation(pParse, 0, iDb); @@ -684,13 +686,16 @@ void sqlite3Pragma( { OP_Integer, 0, 1, 0}, /* 4 */ { OP_SetCookie, 0, BTREE_INCR_VACUUM, 1}, /* 5 */ }; - int iAddr; - iAddr = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6, iLn); - sqlite3VdbeChangeP1(v, iAddr, iDb); - sqlite3VdbeChangeP1(v, iAddr+1, iDb); - sqlite3VdbeChangeP2(v, iAddr+2, iAddr+4); - sqlite3VdbeChangeP1(v, iAddr+4, eAuto-1); - sqlite3VdbeChangeP1(v, iAddr+5, iDb); + VdbeOp *aOp; + int iAddr = sqlite3VdbeCurrentAddr(v); + sqlite3VdbeVerifyAvailableSpace(v, ArraySize(setMeta6)); + aOp = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6, iLn); + assert( aOp!=0 ); + aOp[0].p1 = iDb; + aOp[1].p1 = iDb; + aOp[2].p2 = iAddr+4; + aOp[4].p1 = eAuto - 1; + aOp[5].p1 = iDb; sqlite3VdbeUsesBtree(v, iDb); } } @@ -1396,18 +1401,6 @@ void sqlite3Pragma( case PragTyp_INTEGRITY_CHECK: { int i, j, addr, mxErr; - /* Code that appears at the end of the integrity check. If no error - ** messages have been generated, output OK. Otherwise output the - ** error message - */ - static const int iLn = VDBE_OFFSET_LINENO(2); - static const VdbeOpList endCode[] = { - { OP_AddImm, 1, 0, 0}, /* 0 */ - { OP_If, 1, 0, 0}, /* 1 */ - { OP_String8, 0, 3, 0}, /* 2 */ - { OP_ResultRow, 3, 1, 0}, - }; - int isQuick = (sqlite3Tolower(zLeft[0])=='q'); /* If the PRAGMA command was of the form "PRAGMA .integrity_check", @@ -1604,10 +1597,24 @@ void sqlite3Pragma( #endif /* SQLITE_OMIT_BTREECOUNT */ } } - addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode, iLn); - sqlite3VdbeChangeP2(v, addr, -mxErr); - sqlite3VdbeJumpHere(v, addr+1); - sqlite3VdbeChangeP4(v, addr+2, "ok", P4_STATIC); + { + static const int iLn = VDBE_OFFSET_LINENO(2); + static const VdbeOpList endCode[] = { + { OP_AddImm, 1, 0, 0}, /* 0 */ + { OP_If, 1, 0, 0}, /* 1 */ + { OP_String8, 0, 3, 0}, /* 2 */ + { OP_ResultRow, 3, 1, 0}, + }; + VdbeOp *aOp; + + aOp = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode, iLn); + if( aOp ){ + aOp[0].p2 = -mxErr; + aOp[1].p2 = sqlite3VdbeCurrentAddr(v); + aOp[2].p4type = P4_STATIC; + aOp[2].p4.z = "ok"; + } + } } break; #endif /* SQLITE_OMIT_INTEGRITY_CHECK */ @@ -1724,11 +1731,14 @@ void sqlite3Pragma( { OP_Integer, 0, 1, 0}, /* 1 */ { OP_SetCookie, 0, 0, 1}, /* 2 */ }; - int addr = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie, 0); - sqlite3VdbeChangeP1(v, addr, iDb); - sqlite3VdbeChangeP1(v, addr+1, sqlite3Atoi(zRight)); - sqlite3VdbeChangeP1(v, addr+2, iDb); - sqlite3VdbeChangeP2(v, addr+2, iCookie); + VdbeOp *aOp; + sqlite3VdbeVerifyAvailableSpace(v, ArraySize(setCookie)); + aOp = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie, 0); + assert( aOp!=0 ); + aOp[0].p1 = iDb; + aOp[1].p1 = sqlite3Atoi(zRight); + aOp[2].p1 = iDb; + aOp[2].p2 = iCookie; }else{ /* Read the specified cookie value */ static const VdbeOpList readCookie[] = { @@ -1736,10 +1746,13 @@ void sqlite3Pragma( { OP_ReadCookie, 0, 1, 0}, /* 1 */ { OP_ResultRow, 1, 1, 0} }; - int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie, 0); - sqlite3VdbeChangeP1(v, addr, iDb); - sqlite3VdbeChangeP1(v, addr+1, iDb); - sqlite3VdbeChangeP3(v, addr+1, iCookie); + VdbeOp *aOp; + sqlite3VdbeVerifyAvailableSpace(v, ArraySize(readCookie)); + aOp = sqlite3VdbeAddOpList(v, ArraySize(readCookie),readCookie,0); + assert( aOp!=0 ); + aOp[0].p1 = iDb; + aOp[1].p1 = iDb; + aOp[1].p3 = iCookie; sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, SQLITE_TRANSIENT); } diff --git a/src/vdbe.h b/src/vdbe.h index 68a4f6b2a8..a0ff16d891 100644 --- a/src/vdbe.h +++ b/src/vdbe.h @@ -180,7 +180,12 @@ int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int); int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int); int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int); int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int); -int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno); +#ifdef SQLITE_DEBUG + void sqlite3VdbeVerifyAvailableSpace(Vdbe *p, int N); +#else +# define sqlite3VdbeVerifyAvailableSpace(A,B) +#endif +VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno); void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*); void sqlite3VdbeChangeOpcode(Vdbe*, u32 addr, u8); void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1); @@ -188,7 +193,7 @@ void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2); void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3); void sqlite3VdbeChangeP5(Vdbe*, u8 P5); void sqlite3VdbeJumpHere(Vdbe*, int addr); -void sqlite3VdbeChangeToNoop(Vdbe*, int addr); +int sqlite3VdbeChangeToNoop(Vdbe*, int addr); int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op); void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N); void sqlite3VdbeSetP4KeyInfo(Parse*, Index*); diff --git a/src/vdbeaux.c b/src/vdbeaux.c index 758c85fd1c..9859054ba4 100644 --- a/src/vdbeaux.c +++ b/src/vdbeaux.c @@ -250,8 +250,7 @@ void sqlite3VdbeMultiLoad(Vdbe *p, int iDest, const char *zTypes, ...){ for(i=0; (c = zTypes[i])!=0; i++){ if( c=='s' ){ const char *z = va_arg(ap, const char*); - int addr = sqlite3VdbeAddOp2(p, z==0 ? OP_Null : OP_String8, 0, iDest++); - if( z ) sqlite3VdbeChangeP4(p, addr, z, 0); + sqlite3VdbeAddOp4(p, z==0 ? OP_Null : OP_String8, 0, iDest++, 0, z, 0); }else{ assert( c=='i' ); sqlite3VdbeAddOp2(p, OP_Integer, va_arg(ap, int), iDest++); @@ -606,6 +605,17 @@ int sqlite3VdbeCurrentAddr(Vdbe *p){ return p->nOp; } +/* +** Verify that at least N opcode slots are available in p without +** having to malloc for more space. This interface is used for +** testing only. +*/ +#ifdef SQLITE_DEBUG +void sqlite3VdbeVerifyAvailableSpace(Vdbe *p, int N){ + assert( p->nOp + N <= p->pParse->nOpAlloc ); +} +#endif + /* ** This function returns a pointer to the array of opcodes associated with ** the Vdbe passed as the first argument. It is the callers responsibility @@ -631,19 +641,23 @@ VdbeOp *sqlite3VdbeTakeOpArray(Vdbe *p, int *pnOp, int *pnMaxArg){ } /* -** Add a whole list of operations to the operation stack. Return the -** address of the first operation added. +** Add a whole list of operations to the operation stack. Return a +** pointer to the first operation inserted. */ -int sqlite3VdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp, int iLineno){ - int addr, i; - VdbeOp *pOut; +VdbeOp *sqlite3VdbeAddOpList( + Vdbe *p, /* Add opcodes to the prepared statement */ + int nOp, /* Number of opcodes to add */ + VdbeOpList const *aOp, /* The opcodes to be added */ + int iLineno /* Source-file line number of first opcode */ +){ + int i; + VdbeOp *pOut, *pFirst; assert( nOp>0 ); assert( p->magic==VDBE_MAGIC_INIT ); if( p->nOp + nOp > p->pParse->nOpAlloc && growOpArray(p, nOp) ){ return 0; } - addr = p->nOp; - pOut = &p->aOp[addr]; + pFirst = pOut = &p->aOp[p->nOp]; for(i=0; iopcode = aOp->opcode; pOut->p1 = aOp->p1; @@ -663,12 +677,12 @@ int sqlite3VdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp, int iLineno){ #endif #ifdef SQLITE_DEBUG if( p->db->flags & SQLITE_VdbeAddopTrace ){ - sqlite3VdbePrintOp(0, i+addr, &p->aOp[i+addr]); + sqlite3VdbePrintOp(0, i+p->nOp, &p->aOp[i+p->nOp]); } #endif } p->nOp += nOp; - return addr; + return pFirst; } #if defined(SQLITE_ENABLE_STMT_SCANSTATUS) @@ -826,14 +840,15 @@ void sqlite3VdbeLinkSubProgram(Vdbe *pVdbe, SubProgram *p){ /* ** Change the opcode at addr into OP_Noop */ -void sqlite3VdbeChangeToNoop(Vdbe *p, int addr){ - if( addrnOp ){ - VdbeOp *pOp = &p->aOp[addr]; - sqlite3 *db = p->db; - freeP4(db, pOp->p4type, pOp->p4.p); - memset(pOp, 0, sizeof(pOp[0])); - pOp->opcode = OP_Noop; - } +int sqlite3VdbeChangeToNoop(Vdbe *p, int addr){ + VdbeOp *pOp; + if( p->db->mallocFailed ) return 0; + assert( addr>=0 && addrnOp ); + pOp = &p->aOp[addr]; + freeP4(p->db, pOp->p4type, pOp->p4.p); + memset(pOp, 0, sizeof(pOp[0])); + pOp->opcode = OP_Noop; + return 1; } /* @@ -842,8 +857,7 @@ void sqlite3VdbeChangeToNoop(Vdbe *p, int addr){ */ int sqlite3VdbeDeletePriorOpcode(Vdbe *p, u8 op){ if( (p->nOp-1)>(p->pParse->iFixedOp) && p->aOp[p->nOp-1].opcode==op ){ - sqlite3VdbeChangeToNoop(p, p->nOp-1); - return 1; + return sqlite3VdbeChangeToNoop(p, p->nOp-1); }else{ return 0; } diff --git a/src/vdbeblob.c b/src/vdbeblob.c index a4718efacc..e5f08ce933 100644 --- a/src/vdbeblob.c +++ b/src/vdbeblob.c @@ -115,38 +115,6 @@ int sqlite3_blob_open( ){ int nAttempt = 0; int iCol; /* Index of zColumn in row-record */ - - /* This VDBE program seeks a btree cursor to the identified - ** db/table/row entry. The reason for using a vdbe program instead - ** of writing code to use the b-tree layer directly is that the - ** vdbe program will take advantage of the various transaction, - ** locking and error handling infrastructure built into the vdbe. - ** - ** After seeking the cursor, the vdbe executes an OP_ResultRow. - ** Code external to the Vdbe then "borrows" the b-tree cursor and - ** uses it to implement the blob_read(), blob_write() and - ** blob_bytes() functions. - ** - ** The sqlite3_blob_close() function finalizes the vdbe program, - ** which closes the b-tree cursor and (possibly) commits the - ** transaction. - */ - static const int iLn = VDBE_OFFSET_LINENO(4); - static const VdbeOpList openBlob[] = { - /* {OP_Transaction, 0, 0, 0}, // 0: Inserted separately */ - {OP_TableLock, 0, 0, 0}, /* 1: Acquire a read or write lock */ - /* One of the following two instructions is replaced by an OP_Noop. */ - {OP_OpenRead, 0, 0, 0}, /* 2: Open cursor 0 for reading */ - {OP_OpenWrite, 0, 0, 0}, /* 3: Open cursor 0 for read/write */ - {OP_Variable, 1, 1, 1}, /* 4: Push the rowid to the stack */ - {OP_NotExists, 0, 10, 1}, /* 5: Seek the cursor */ - {OP_Column, 0, 0, 1}, /* 6 */ - {OP_ResultRow, 1, 0, 0}, /* 7 */ - {OP_Goto, 0, 4, 0}, /* 8 */ - {OP_Close, 0, 0, 0}, /* 9 */ - {OP_Halt, 0, 0, 0}, /* 10 */ - }; - int rc = SQLITE_OK; char *zErr = 0; Table *pTab; @@ -265,45 +233,80 @@ int sqlite3_blob_open( pBlob->pStmt = (sqlite3_stmt *)sqlite3VdbeCreate(pParse); assert( pBlob->pStmt || db->mallocFailed ); if( pBlob->pStmt ){ + + /* This VDBE program seeks a btree cursor to the identified + ** db/table/row entry. The reason for using a vdbe program instead + ** of writing code to use the b-tree layer directly is that the + ** vdbe program will take advantage of the various transaction, + ** locking and error handling infrastructure built into the vdbe. + ** + ** After seeking the cursor, the vdbe executes an OP_ResultRow. + ** Code external to the Vdbe then "borrows" the b-tree cursor and + ** uses it to implement the blob_read(), blob_write() and + ** blob_bytes() functions. + ** + ** The sqlite3_blob_close() function finalizes the vdbe program, + ** which closes the b-tree cursor and (possibly) commits the + ** transaction. + */ + static const int iLn = VDBE_OFFSET_LINENO(3); + static const VdbeOpList openBlob[] = { + /* {OP_Transaction, 0, 0, 0}, // inserted separately */ + {OP_TableLock, 0, 0, 0}, /* 0: Acquire a read or write lock */ + {OP_OpenRead, 0, 0, 0}, /* 1: Open cursor 0 for reading */ + {OP_OpenWrite, 0, 0, 0}, /* 2: Open cursor 0 for read/write */ + {OP_Variable, 1, 1, 1}, /* 3: Push the rowid to the stack */ + {OP_NotExists, 0, 10, 1}, /* 4: Seek the cursor */ + {OP_Column, 0, 0, 1}, /* 5 */ + {OP_ResultRow, 1, 0, 0}, /* 6 */ + {OP_Goto, 0, 4, 0}, /* 7 */ + {OP_Close, 0, 0, 0}, /* 8 */ + {OP_Halt, 0, 0, 0}, /* 9 */ + }; Vdbe *v = (Vdbe *)pBlob->pStmt; int iDb = sqlite3SchemaToIndex(db, pTab->pSchema); - + VdbeOp *aOp; sqlite3VdbeAddOp4Int(v, OP_Transaction, iDb, flags, pTab->pSchema->schema_cookie, pTab->pSchema->iGeneration); sqlite3VdbeChangeP5(v, 1); - sqlite3VdbeAddOpList(v, ArraySize(openBlob), openBlob, iLn); + aOp = sqlite3VdbeAddOpList(v, ArraySize(openBlob), openBlob, iLn); /* Make sure a mutex is held on the table to be accessed */ sqlite3VdbeUsesBtree(v, iDb); - /* Configure the OP_TableLock instruction */ + if( db->mallocFailed==0 ){ + assert( aOp!=0 ); + /* Configure the OP_TableLock instruction */ #ifdef SQLITE_OMIT_SHARED_CACHE - sqlite3VdbeChangeToNoop(v, 1); + aOp[0].opcode = OP_Noop; #else - sqlite3VdbeChangeP1(v, 1, iDb); - sqlite3VdbeChangeP2(v, 1, pTab->tnum); - sqlite3VdbeChangeP3(v, 1, flags); - sqlite3VdbeChangeP4(v, 1, pTab->zName, P4_TRANSIENT); + aOp[0].p1 = iDb; + aOp[0].p2 = pTab->tnum; + aOp[0].p3 = flags; + sqlite3VdbeChangeP4(v, 1, pTab->zName, P4_TRANSIENT); + } + if( db->mallocFailed==0 ){ #endif - /* Remove either the OP_OpenWrite or OpenRead. Set the P2 - ** parameter of the other to pTab->tnum. */ - sqlite3VdbeChangeToNoop(v, 3 - flags); - sqlite3VdbeChangeP2(v, 2 + flags, pTab->tnum); - sqlite3VdbeChangeP3(v, 2 + flags, iDb); - - /* Configure the number of columns. Configure the cursor to - ** think that the table has one more column than it really - ** does. An OP_Column to retrieve this imaginary column will - ** always return an SQL NULL. This is useful because it means - ** we can invoke OP_Column to fill in the vdbe cursors type - ** and offset cache without causing any IO. - */ - sqlite3VdbeChangeP4(v, 2+flags, SQLITE_INT_TO_PTR(pTab->nCol+1),P4_INT32); - sqlite3VdbeChangeP2(v, 6, pTab->nCol); - if( !db->mallocFailed ){ + /* Remove either the OP_OpenWrite or OpenRead. Set the P2 + ** parameter of the other to pTab->tnum. */ + aOp[2-flags].opcode = OP_Noop; + aOp[1+flags].p2 = pTab->tnum; + aOp[1+flags].p3 = iDb; + + /* Configure the number of columns. Configure the cursor to + ** think that the table has one more column than it really + ** does. An OP_Column to retrieve this imaginary column will + ** always return an SQL NULL. This is useful because it means + ** we can invoke OP_Column to fill in the vdbe cursors type + ** and offset cache without causing any IO. + */ + aOp[1+flags].p4type = P4_INT32; + aOp[1+flags].p4.i = pTab->nCol+1; + aOp[5].p2 = pTab->nCol; + pParse->nVar = 1; pParse->nMem = 1; pParse->nTab = 1;