/* ** Generate code for the trigger program associated with trigger p on ** table pTab. The reg, orconf and ignoreJump parameters passed to this ** function are the same as those described in the header function for ** sqlite3CodeRowTrigger() */ SQLITE_PRIVATE void sqlite3CodeRowTriggerDirect( Parse *pParse, /* Parse context */ Trigger *p, /* Trigger to code */ Table *pTab, /* The table to code triggers from */ int reg, /* Reg array containing OLD.* and NEW.* values */ int orconf, /* ON CONFLICT policy */ int ignoreJump /* Instruction to jump to for RAISE(IGNORE) */ ){ Vdbe *v = sqlite3GetVdbe(pParse); /* Main VM */ TriggerPrg *pPrg; pPrg = getRowTrigger(pParse, p, pTab, orconf); assert( pPrg || pParse->nErr || pParse->db->mallocFailed ); /* Code the OP_Program opcode in the parent VDBE. P4 of the OP_Program ** is a pointer to the sub-vdbe containing the trigger program. */ if( pPrg ){ int bRecursive = (p->zName && 0==(pParse->db->flags&SQLITE_RecTriggers)); sqlite3VdbeAddOp3(v, OP_Program, reg, ignoreJump, ++pParse->nMem); sqlite3VdbeChangeP4(v, -1, (const char *)pPrg->pProgram, P4_SUBPROGRAM); VdbeComment( (v, "Call: %s.%s", (p->zName?p->zName:"fkey"), onErrorText(orconf))); /* Set the P5 operand of the OP_Program instruction to non-zero if ** recursive invocation of this trigger program is disallowed. Recursive ** invocation is disallowed if (a) the sub-program is really a trigger, ** not a foreign key action, and (b) the flag to enable recursive triggers ** is clear. */ sqlite3VdbeChangeP5(v, (u8)bRecursive); } }
/* ** Generate code that will open cursors for a table and for all ** indices of that table. The "base" parameter is the cursor number used ** for the table. Indices are opened on subsequent cursors. */ void sqlite3OpenTableAndIndices( Parse *pParse, /* Parsing context */ Table *pTab, /* Table to be opened */ int base, /* Cursor number assigned to the table */ int op /* OP_OpenRead or OP_OpenWrite */ ){ int i; int iDb; Index *pIdx; Vdbe *v; if( IsVirtual(pTab) ) return; iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); v = sqlite3GetVdbe(pParse); assert( v!=0 ); sqlite3OpenTable(pParse, base, iDb, pTab, op); for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx); assert( pIdx->pSchema==pTab->pSchema ); sqlite3VdbeAddOp(v, OP_Integer, iDb, 0); VdbeComment((v, "# %s", pIdx->zName)); sqlite3VdbeOp3(v, op, i+base, pIdx->tnum, (char*)pKey, P3_KEYINFO_HANDOFF); } if( pParse->nTab<=base+i ){ pParse->nTab = base+i; } }
/* ** Generate code that will open a table for reading. */ void sqlite3OpenTableForReading( Vdbe *v, /* Generate code into this VDBE */ int iCur, /* The cursor number of the table */ Table *pTab /* The table to be opened */ ){ sqlite3VdbeAddOp(v, OP_Integer, pTab->iDb, 0); sqlite3VdbeAddOp(v, OP_OpenRead, iCur, pTab->tnum); VdbeComment((v, "# %s", pTab->zName)); sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, pTab->nCol); }
/* ** Generate bytecode that does an UPDATE as part of an upsert. ** ** If pIdx is NULL, then the UNIQUE constraint that failed was the IPK. ** In this case parameter iCur is a cursor open on the table b-tree that ** currently points to the conflicting table row. Otherwise, if pIdx ** is not NULL, then pIdx is the constraint that failed and iCur is a ** cursor points to the conflicting row. */ void sqlite3UpsertDoUpdate( Parse *pParse, /* The parsing and code-generating context */ Upsert *pUpsert, /* The ON CONFLICT clause for the upsert */ Table *pTab, /* The table being updated */ Index *pIdx, /* The UNIQUE constraint that failed */ int iCur /* Cursor for pIdx (or pTab if pIdx==NULL) */ ){ Vdbe *v = pParse->pVdbe; sqlite3 *db = pParse->db; SrcList *pSrc; /* FROM clause for the UPDATE */ int iDataCur; assert( v!=0 ); assert( pUpsert!=0 ); VdbeNoopComment((v, "Begin DO UPDATE of UPSERT")); iDataCur = pUpsert->iDataCur; if( pIdx && iCur!=iDataCur ){ if( HasRowid(pTab) ){ int regRowid = sqlite3GetTempReg(pParse); sqlite3VdbeAddOp2(v, OP_IdxRowid, iCur, regRowid); sqlite3VdbeAddOp3(v, OP_SeekRowid, iDataCur, 0, regRowid); VdbeCoverage(v); sqlite3ReleaseTempReg(pParse, regRowid); }else{ Index *pPk = sqlite3PrimaryKeyIndex(pTab); int nPk = pPk->nKeyCol; int iPk = pParse->nMem+1; int i; pParse->nMem += nPk; for(i=0; i<nPk; i++){ int k; assert( pPk->aiColumn[i]>=0 ); k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]); sqlite3VdbeAddOp3(v, OP_Column, iCur, k, iPk+i); VdbeComment((v, "%s.%s", pIdx->zName, pTab->aCol[pPk->aiColumn[i]].zName)); } sqlite3VdbeVerifyAbortable(v, OE_Abort); i = sqlite3VdbeAddOp4Int(v, OP_Found, iDataCur, 0, iPk, nPk); VdbeCoverage(v); sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CORRUPT, OE_Abort, 0, "corrupt database", P4_STATIC); sqlite3VdbeJumpHere(v, i); } } /* pUpsert does not own pUpsertSrc - the outer INSERT statement does. So ** we have to make a copy before passing it down into sqlite3Update() */ pSrc = sqlite3SrcListDup(db, pUpsert->pUpsertSrc, 0); sqlite3Update(pParse, pSrc, pUpsert->pUpsertSet, pUpsert->pUpsertWhere, OE_Abort, 0, 0, pUpsert); pUpsert->pUpsertSet = 0; /* Will have been deleted by sqlite3Update() */ pUpsert->pUpsertWhere = 0; /* Will have been deleted by sqlite3Update() */ VdbeNoopComment((v, "End DO UPDATE of UPSERT")); }
/* ** The most recently coded instruction was an OP_Column to retrieve the ** i-th column of table pTab. This routine sets the P3 parameter of the ** OP_Column to the default value, if any. ** ** The default value of a column is specified by a DEFAULT clause in the ** column definition. This was either supplied by the user when the table ** was created, or added later to the table definition by an ALTER TABLE ** command. If the latter, then the row-records in the table btree on disk ** may not contain a value for the column and the default value, taken ** from the P3 parameter of the OP_Column instruction, is returned instead. ** If the former, then all row-records are guaranteed to include a value ** for the column and the P3 value is not required. ** ** Column definitions created by an ALTER TABLE command may only have ** literal default values specified: a number, null or a string. (If a more ** complicated default expression value was provided, it is evaluated ** when the ALTER TABLE is executed and one of the literal values written ** into the sqlite_master table.) ** ** Therefore, the P3 parameter is only required if the default value for ** the column is a literal number, string or null. The sqlite3ValueFromExpr() ** function is capable of transforming these types of expressions into ** sqlite3_value objects. */ void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i){ if( pTab && !pTab->pSelect ){ sqlite3_value *pValue; u8 enc = ENC(sqlite3VdbeDb(v)); Column *pCol = &pTab->aCol[i]; sqlite3ValueFromExpr(pCol->pDflt, enc, pCol->affinity, &pValue); if( pValue ){ sqlite3VdbeChangeP3(v, -1, (const char *)pValue, P3_MEM); }else{ VdbeComment((v, "# %s.%s", pTab->zName, pCol->zName)); } } }
/* ** Generate code that will open a table for reading. */ void sqlite3OpenTable( Parse *p, /* Generate code into this VDBE */ int iCur, /* The cursor number of the table */ int iDb, /* The database index in sqlite3.aDb[] */ Table *pTab, /* The table to be opened */ int opcode /* OP_OpenRead or OP_OpenWrite */ ){ Vdbe *v = sqlite3GetVdbe(p); assert( opcode==OP_OpenWrite || opcode==OP_OpenRead ); sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite), pTab->zName); sqlite3VdbeAddOp(v, OP_Integer, iDb, 0); VdbeComment((v, "# %s", pTab->zName)); sqlite3VdbeAddOp(v, opcode, iCur, pTab->tnum); sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, pTab->nCol); }
/* ** Generate code that will open cursors for a table and for all ** indices of that table. The "base" parameter is the cursor number used ** for the table. Indices are opened on subsequent cursors. */ void sqlite3OpenTableAndIndices( Parse *pParse, /* Parsing context */ Table *pTab, /* Table to be opened */ int base, /* Cursor number assigned to the table */ int op /* OP_OpenRead or OP_OpenWrite */ ){ int i; Index *pIdx; Vdbe *v = sqlite3GetVdbe(pParse); assert( v!=0 ); sqlite3VdbeAddOp(v, OP_Integer, pTab->iDb, 0); VdbeComment((v, "# %s", pTab->zName)); sqlite3VdbeAddOp(v, op, base, pTab->tnum); sqlite3VdbeAddOp(v, OP_SetNumColumns, base, pTab->nCol); for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ sqlite3VdbeAddOp(v, OP_Integer, pIdx->iDb, 0); VdbeComment((v, "# %s", pIdx->zName)); sqlite3VdbeOp3(v, op, i+base, pIdx->tnum, (char*)&pIdx->keyInfo, P3_KEYINFO); } if( pParse->nTab<=base+i ){ pParse->nTab = base+i; } }
/* ** The most recently coded instruction was an OP_Column to retrieve the ** i-th column of table pTab. This routine sets the P4 parameter of the ** OP_Column to the default value, if any. ** ** The default value of a column is specified by a DEFAULT clause in the ** column definition. This was either supplied by the user when the table ** was created, or added later to the table definition by an ALTER TABLE ** command. If the latter, then the row-records in the table btree on disk ** may not contain a value for the column and the default value, taken ** from the P4 parameter of the OP_Column instruction, is returned instead. ** If the former, then all row-records are guaranteed to include a value ** for the column and the P4 value is not required. ** ** Column definitions created by an ALTER TABLE command may only have ** literal default values specified: a number, null or a string. (If a more ** complicated default expression value was provided, it is evaluated ** when the ALTER TABLE is executed and one of the literal values written ** into the sqlite_master table.) ** ** Therefore, the P4 parameter is only required if the default value for ** the column is a literal number, string or null. The sqlite3ValueFromExpr() ** function is capable of transforming these types of expressions into ** sqlite3_value objects. ** ** If parameter iReg is not negative, code an OP_RealAffinity instruction ** on register iReg. This is used when an equivalent integer value is ** stored in place of an 8-byte floating point value in order to save ** space. */ void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){ assert( pTab!=0 ); if( !pTab->pSelect ){ sqlite3_value *pValue = 0; u8 enc = ENC(sqlite3VdbeDb(v)); Column *pCol = &pTab->aCol[i]; VdbeComment((v, "%s.%s", pTab->zName, pCol->zName)); assert( i<pTab->nCol ); sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, pCol->affinity, &pValue); if( pValue ){ sqlite3VdbeChangeP4(v, -1, (const char *)pValue, P4_MEM); } #ifndef SQLITE_OMIT_FLOATING_POINT if( pTab->aCol[i].affinity==SQLITE_AFF_REAL ){ sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg); } #endif } }
/* ** Create and populate a new TriggerPrg object with a sub-program ** implementing trigger pTrigger with ON CONFLICT policy orconf. */ static TriggerPrg *codeRowTrigger( Parse *pParse, /* Current parse context */ Trigger *pTrigger, /* Trigger to code */ Table *pTab, /* The table pTrigger is attached to */ int orconf /* ON CONFLICT policy to code trigger program with */ ){ Parse *pTop = sqlite3ParseToplevel(pParse); sqlite3 *db = pParse->db; /* Database handle */ TriggerPrg *pPrg; /* Value to return */ Expr *pWhen = 0; /* Duplicate of trigger WHEN expression */ Vdbe *v; /* Temporary VM */ NameContext sNC; /* Name context for sub-vdbe */ SubProgram *pProgram = 0; /* Sub-vdbe for trigger program */ Parse *pSubParse; /* Parse context for sub-vdbe */ int iEndTrigger = 0; /* Label to jump to if WHEN is false */ assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) ); assert( pTop->pVdbe ); /* Allocate the TriggerPrg and SubProgram objects. To ensure that they ** are freed if an error occurs, link them into the Parse.pTriggerPrg ** list of the top-level Parse object sooner rather than later. */ pPrg = sqlite3DbMallocZero(db, sizeof(TriggerPrg)); if( !pPrg ) return 0; pPrg->pNext = pTop->pTriggerPrg; pTop->pTriggerPrg = pPrg; pPrg->pProgram = pProgram = sqlite3DbMallocZero(db, sizeof(SubProgram)); if( !pProgram ) return 0; sqlite3VdbeLinkSubProgram(pTop->pVdbe, pProgram); pPrg->pTrigger = pTrigger; pPrg->orconf = orconf; pPrg->aColmask[0] = 0xffffffff; pPrg->aColmask[1] = 0xffffffff; /* Allocate and populate a new Parse context to use for coding the ** trigger sub-program. */ pSubParse = sqlite3StackAllocZero(db, sizeof(Parse)); if( !pSubParse ) return 0; memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pSubParse; pSubParse->db = db; pSubParse->pTriggerTab = pTab; pSubParse->pToplevel = pTop; pSubParse->zAuthContext = pTrigger->zName; pSubParse->eTriggerOp = pTrigger->op; pSubParse->nQueryLoop = pParse->nQueryLoop; v = sqlite3GetVdbe(pSubParse); if( v ){ VdbeComment((v, "Start: %s.%s (%s %s%s%s ON %s)", pTrigger->zName, onErrorText(orconf), (pTrigger->tr_tm==TRIGGER_BEFORE ? "BEFORE" : "AFTER"), (pTrigger->op==TK_UPDATE ? "UPDATE" : ""), (pTrigger->op==TK_INSERT ? "INSERT" : ""), (pTrigger->op==TK_DELETE ? "DELETE" : ""), pTab->zName )); #ifndef SQLITE_OMIT_TRACE sqlite3VdbeChangeP4(v, -1, sqlite3MPrintf(db, "-- TRIGGER %s", pTrigger->zName), P4_DYNAMIC ); #endif /* If one was specified, code the WHEN clause. If it evaluates to false ** (or NULL) the sub-vdbe is immediately halted by jumping to the ** OP_Halt inserted at the end of the program. */ if( pTrigger->pWhen ){ pWhen = sqlite3ExprDup(db, pTrigger->pWhen, 0); if( SQLITE_OK==sqlite3ResolveExprNames(&sNC, pWhen) && db->mallocFailed==0 ){ iEndTrigger = sqlite3VdbeMakeLabel(v); sqlite3ExprIfFalse(pSubParse, pWhen, iEndTrigger, SQLITE_JUMPIFNULL); } sqlite3ExprDelete(db, pWhen); } /* Code the trigger program into the sub-vdbe. */ codeTriggerProgram(pSubParse, pTrigger->step_list, orconf); /* Insert an OP_Halt at the end of the sub-program. */ if( iEndTrigger ){ sqlite3VdbeResolveLabel(v, iEndTrigger); } sqlite3VdbeAddOp0(v, OP_Halt); VdbeComment((v, "End: %s.%s", pTrigger->zName, onErrorText(orconf))); transferParseError(pParse, pSubParse); if( db->mallocFailed==0 ){ pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pTop->nMaxArg); } pProgram->nMem = pSubParse->nMem; pProgram->nCsr = pSubParse->nTab; pProgram->nOnce = pSubParse->nOnce; pProgram->token = (void *)pTrigger; pPrg->aColmask[0] = pSubParse->oldmask; pPrg->aColmask[1] = pSubParse->newmask; sqlite3VdbeDelete(v); } assert( !pSubParse->pAinc && !pSubParse->pZombieTab ); assert( !pSubParse->pTriggerPrg && !pSubParse->nMaxArg ); sqlite3StackFree(db, pSubParse); return pPrg; }
/* ** Generate VDBE code for zero or more statements inside the body of a ** trigger. */ static int codeTriggerProgram( Parse *pParse, /* The parser context */ TriggerStep *pStepList, /* List of statements inside the trigger body */ int orconfin /* Conflict algorithm. (OE_Abort, etc) */ ){ TriggerStep * pTriggerStep = pStepList; int orconf; Vdbe *v = pParse->pVdbe; sqlite3 *db = pParse->db; assert( pTriggerStep!=0 ); assert( v!=0 ); sqlite3VdbeAddOp(v, OP_ContextPush, 0, 0); VdbeComment((v, "# begin trigger %s", pStepList->pTrig->name)); while( pTriggerStep ){ orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin; pParse->trigStack->orconf = orconf; switch( pTriggerStep->op ){ case TK_SELECT: { Select *ss = sqlite3SelectDup(db, pTriggerStep->pSelect); if( ss ){ sqlite3SelectResolve(pParse, ss, 0); sqlite3Select(pParse, ss, SRT_Discard, 0, 0, 0, 0, 0); sqlite3SelectDelete(ss); } break; } case TK_UPDATE: { SrcList *pSrc; pSrc = targetSrcList(pParse, pTriggerStep); sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0); sqlite3Update(pParse, pSrc, sqlite3ExprListDup(db, pTriggerStep->pExprList), sqlite3ExprDup(db, pTriggerStep->pWhere), orconf); sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0); break; } case TK_INSERT: { SrcList *pSrc; pSrc = targetSrcList(pParse, pTriggerStep); sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0); sqlite3Insert(pParse, pSrc, sqlite3ExprListDup(db, pTriggerStep->pExprList), sqlite3SelectDup(db, pTriggerStep->pSelect), sqlite3IdListDup(db, pTriggerStep->pIdList), orconf); sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0); break; } case TK_DELETE: { SrcList *pSrc; sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0); pSrc = targetSrcList(pParse, pTriggerStep); sqlite3DeleteFrom(pParse, pSrc, sqlite3ExprDup(db, pTriggerStep->pWhere)); sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0); break; } default: assert(0); } pTriggerStep = pTriggerStep->pNext; } sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0); VdbeComment((v, "# end trigger %s", pStepList->pTrig->name)); return 0; }
/* ** Generate code to do an analysis of all indices associated with ** a single table. */ static void analyzeOneTable( Parse *pParse, /* Parser context */ Table *pTab, /* Table whose indices are to be analyzed */ int iStatCur, /* Cursor that writes to the sqlite_stat1 table */ int iMem /* Available memory locations begin here */ ){ Index *pIdx; /* An index to being analyzed */ int iIdxCur; /* Cursor number for index being analyzed */ int nCol; /* Number of columns in the index */ Vdbe *v; /* The virtual machine being built up */ int i; /* Loop counter */ int topOfLoop; /* The top of the loop */ int endOfLoop; /* The end of the loop */ int addr; /* The address of an instruction */ int iDb; /* Index of database containing pTab */ v = sqlite3GetVdbe(pParse); if( v==0 || pTab==0 || pTab->pIndex==0 ){ /* Do no analysis for tables that have no indices */ return; } assert( sqlite3BtreeHoldsAllMutexes(pParse->db) ); iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); assert( iDb>=0 ); #ifndef SQLITE_OMIT_AUTHORIZATION if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0, pParse->db->aDb[iDb].zName ) ){ return; } #endif /* Establish a read-lock on the table at the shared-cache level. */ sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName); iIdxCur = pParse->nTab; for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx); /* Open a cursor to the index to be analyzed */ assert( iDb==sqlite3SchemaToIndex(pParse->db, pIdx->pSchema) ); sqlite3VdbeAddOp(v, OP_Integer, iDb, 0); VdbeComment((v, "# %s", pIdx->zName)); sqlite3VdbeOp3(v, OP_OpenRead, iIdxCur, pIdx->tnum, (char *)pKey, P3_KEYINFO_HANDOFF); nCol = pIdx->nColumn; if( iMem+nCol*2>=pParse->nMem ){ pParse->nMem = iMem+nCol*2+1; } sqlite3VdbeAddOp(v, OP_SetNumColumns, iIdxCur, nCol+1); /* Memory cells are used as follows: ** ** mem[iMem]: The total number of rows in the table. ** mem[iMem+1]: Number of distinct values in column 1 ** ... ** mem[iMem+nCol]: Number of distinct values in column N ** mem[iMem+nCol+1] Last observed value of column 1 ** ... ** mem[iMem+nCol+nCol]: Last observed value of column N ** ** Cells iMem through iMem+nCol are initialized to 0. The others ** are initialized to NULL. */ for(i=0; i<=nCol; i++){ sqlite3VdbeAddOp(v, OP_MemInt, 0, iMem+i); } for(i=0; i<nCol; i++){ sqlite3VdbeAddOp(v, OP_MemNull, iMem+nCol+i+1, 0); } /* Do the analysis. */ endOfLoop = sqlite3VdbeMakeLabel(v); sqlite3VdbeAddOp(v, OP_Rewind, iIdxCur, endOfLoop); topOfLoop = sqlite3VdbeCurrentAddr(v); sqlite3VdbeAddOp(v, OP_MemIncr, 1, iMem); for(i=0; i<nCol; i++){ sqlite3VdbeAddOp(v, OP_Column, iIdxCur, i); sqlite3VdbeAddOp(v, OP_MemLoad, iMem+nCol+i+1, 0); sqlite3VdbeAddOp(v, OP_Ne, 0x100, 0); } sqlite3VdbeAddOp(v, OP_Goto, 0, endOfLoop); for(i=0; i<nCol; i++){ addr = sqlite3VdbeAddOp(v, OP_MemIncr, 1, iMem+i+1); sqlite3VdbeChangeP2(v, topOfLoop + 3*i + 3, addr); sqlite3VdbeAddOp(v, OP_Column, iIdxCur, i); sqlite3VdbeAddOp(v, OP_MemStore, iMem+nCol+i+1, 1); } sqlite3VdbeResolveLabel(v, endOfLoop); sqlite3VdbeAddOp(v, OP_Next, iIdxCur, topOfLoop); sqlite3VdbeAddOp(v, OP_Close, iIdxCur, 0); /* Store the results. ** ** The result is a single row of the sqlite_stat1 table. The first ** two columns are the names of the table and index. The third column ** is a string composed of a list of integer statistics about the ** index. The first integer in the list is the total number of entires ** in the index. There is one additional integer in the list for each ** column of the table. This additional integer is a guess of how many ** rows of the table the index will select. If D is the count of distinct ** values and K is the total number of rows, then the integer is computed ** as: ** ** I = (K+D-1)/D ** ** If K==0 then no entry is made into the sqlite_stat1 table. ** If K>0 then it is always the case the D>0 so division by zero ** is never possible. */ sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0); addr = sqlite3VdbeAddOp(v, OP_IfNot, 0, 0); sqlite3VdbeAddOp(v, OP_NewRowid, iStatCur, 0); sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->zName, 0); sqlite3VdbeOp3(v, OP_String8, 0, 0, pIdx->zName, 0); sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0); sqlite3VdbeOp3(v, OP_String8, 0, 0, " ", 0); for(i=0; i<nCol; i++){ sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0); sqlite3VdbeAddOp(v, OP_MemLoad, iMem+i+1, 0); sqlite3VdbeAddOp(v, OP_Add, 0, 0); sqlite3VdbeAddOp(v, OP_AddImm, -1, 0); sqlite3VdbeAddOp(v, OP_MemLoad, iMem+i+1, 0); sqlite3VdbeAddOp(v, OP_Divide, 0, 0); sqlite3VdbeAddOp(v, OP_ToInt, 0, 0); if( i==nCol-1 ){ sqlite3VdbeAddOp(v, OP_Concat, nCol*2-1, 0); }else{ sqlite3VdbeAddOp(v, OP_Dup, 1, 0); } } sqlite3VdbeOp3(v, OP_MakeRecord, 3, 0, "aaa", 0); sqlite3VdbeAddOp(v, OP_Insert, iStatCur, OPFLAG_APPEND); sqlite3VdbeJumpHere(v, addr); } }
/* ** Generate code to do an analysis of all indices associated with ** a single table. */ static void analyzeOneTable( Parse *pParse, /* Parser context */ Table *pTab, /* Table whose indices are to be analyzed */ Index *pOnlyIdx, /* If not NULL, only analyze this one index */ int iStatCur, /* Index of VdbeCursor that writes the sqlite_stat1 table */ int iMem /* Available memory locations begin here */ ){ sqlite3 *db = pParse->db; /* Database handle */ Index *pIdx; /* An index to being analyzed */ int iIdxCur; /* Cursor open on index being analyzed */ Vdbe *v; /* The virtual machine being built up */ int i; /* Loop counter */ int topOfLoop; /* The top of the loop */ int endOfLoop; /* The end of the loop */ int jZeroRows = -1; /* Jump from here if number of rows is zero */ int iDb; /* Index of database containing pTab */ int regTabname = iMem++; /* Register containing table name */ int regIdxname = iMem++; /* Register containing index name */ int regSampleno = iMem++; /* Register containing next sample number */ int regCol = iMem++; /* Content of a column analyzed table */ int regRec = iMem++; /* Register holding completed record */ int regTemp = iMem++; /* Temporary use register */ int regRowid = iMem++; /* Rowid for the inserted record */ #ifdef SQLITE_ENABLE_STAT2 int addr = 0; /* Instruction address */ int regTemp2 = iMem++; /* Temporary use register */ int regSamplerecno = iMem++; /* Index of next sample to record */ int regRecno = iMem++; /* Current sample index */ int regLast = iMem++; /* Index of last sample to record */ int regFirst = iMem++; /* Index of first sample to record */ #endif v = sqlite3GetVdbe(pParse); if( v==0 || NEVER(pTab==0) ){ return; } if( pTab->tnum==0 ){ /* Do not gather statistics on views or virtual tables */ return; } if( memcmp(pTab->zName, "sqlite_", 7)==0 ){ /* Do not gather statistics on system tables */ return; } assert( sqlite3BtreeHoldsAllMutexes(db) ); iDb = sqlite3SchemaToIndex(db, pTab->pSchema); assert( iDb>=0 ); assert( sqlite3SchemaMutexHeld(db, iDb, 0) ); #ifndef SQLITE_OMIT_AUTHORIZATION if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0, db->aDb[iDb].zName ) ){ return; } #endif /* Establish a read-lock on the table at the shared-cache level. */ sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName); iIdxCur = pParse->nTab++; sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0); for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ int nCol; KeyInfo *pKey; if( pOnlyIdx && pOnlyIdx!=pIdx ) continue; nCol = pIdx->nColumn; pKey = sqlite3IndexKeyinfo(pParse, pIdx); if( iMem+1+(nCol*2)>pParse->nMem ){ pParse->nMem = iMem+1+(nCol*2); } /* Open a cursor to the index to be analyzed. */ assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) ); sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb, (char *)pKey, P4_KEYINFO_HANDOFF); VdbeComment((v, "%s", pIdx->zName)); /* Populate the register containing the index name. */ sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, pIdx->zName, 0); #ifdef SQLITE_ENABLE_STAT2 /* If this iteration of the loop is generating code to analyze the ** first index in the pTab->pIndex list, then register regLast has ** not been populated. In this case populate it now. */ if( pTab->pIndex==pIdx ){ sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES, regSamplerecno); sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES*2-1, regTemp); sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES*2, regTemp2); sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regLast); sqlite3VdbeAddOp2(v, OP_Null, 0, regFirst); addr = sqlite3VdbeAddOp3(v, OP_Lt, regSamplerecno, 0, regLast); sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regLast, regFirst); sqlite3VdbeAddOp3(v, OP_Multiply, regLast, regTemp, regLast); sqlite3VdbeAddOp2(v, OP_AddImm, regLast, SQLITE_INDEX_SAMPLES*2-2); sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regLast, regLast); sqlite3VdbeJumpHere(v, addr); } /* Zero the regSampleno and regRecno registers. */ sqlite3VdbeAddOp2(v, OP_Integer, 0, regSampleno); sqlite3VdbeAddOp2(v, OP_Integer, 0, regRecno); sqlite3VdbeAddOp2(v, OP_Copy, regFirst, regSamplerecno); #endif /* The block of memory cells initialized here is used as follows. ** ** iMem: ** The total number of rows in the table. ** ** iMem+1 .. iMem+nCol: ** Number of distinct entries in index considering the ** left-most N columns only, where N is between 1 and nCol, ** inclusive. ** ** iMem+nCol+1 .. Mem+2*nCol: ** Previous value of indexed columns, from left to right. ** ** Cells iMem through iMem+nCol are initialized to 0. The others are ** initialized to contain an SQL NULL. */ for(i=0; i<=nCol; i++){ sqlite3VdbeAddOp2(v, OP_Integer, 0, iMem+i); } for(i=0; i<nCol; i++){ sqlite3VdbeAddOp2(v, OP_Null, 0, iMem+nCol+i+1); } /* Start the analysis loop. This loop runs through all the entries in ** the index b-tree. */ endOfLoop = sqlite3VdbeMakeLabel(v); sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop); topOfLoop = sqlite3VdbeCurrentAddr(v); sqlite3VdbeAddOp2(v, OP_AddImm, iMem, 1); for(i=0; i<nCol; i++){ CollSeq *pColl; sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regCol); if( i==0 ){ #ifdef SQLITE_ENABLE_STAT2 /* Check if the record that cursor iIdxCur points to contains a ** value that should be stored in the sqlite_stat2 table. If so, ** store it. */ int ne = sqlite3VdbeAddOp3(v, OP_Ne, regRecno, 0, regSamplerecno); assert( regTabname+1==regIdxname && regTabname+2==regSampleno && regTabname+3==regCol ); sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL); sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 4, regRec, "aaab", 0); sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regRowid); sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regRec, regRowid); /* Calculate new values for regSamplerecno and regSampleno. ** ** sampleno = sampleno + 1 ** samplerecno = samplerecno+(remaining records)/(remaining samples) */ sqlite3VdbeAddOp2(v, OP_AddImm, regSampleno, 1); sqlite3VdbeAddOp3(v, OP_Subtract, regRecno, regLast, regTemp); sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1); sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES, regTemp2); sqlite3VdbeAddOp3(v, OP_Subtract, regSampleno, regTemp2, regTemp2); sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regTemp, regTemp); sqlite3VdbeAddOp3(v, OP_Add, regSamplerecno, regTemp, regSamplerecno); sqlite3VdbeJumpHere(v, ne); sqlite3VdbeAddOp2(v, OP_AddImm, regRecno, 1); #endif /* Always record the very first row */ sqlite3VdbeAddOp1(v, OP_IfNot, iMem+1); } assert( pIdx->azColl!=0 ); assert( pIdx->azColl[i]!=0 ); pColl = sqlite3LocateCollSeq(pParse, pIdx->azColl[i]); sqlite3VdbeAddOp4(v, OP_Ne, regCol, 0, iMem+nCol+i+1, (char*)pColl, P4_COLLSEQ); sqlite3VdbeChangeP5(v, SQLITE_NULLEQ); } if( db->mallocFailed ){ /* If a malloc failure has occurred, then the result of the expression ** passed as the second argument to the call to sqlite3VdbeJumpHere() ** below may be negative. Which causes an assert() to fail (or an ** out-of-bounds write if SQLITE_DEBUG is not defined). */ return; } sqlite3VdbeAddOp2(v, OP_Goto, 0, endOfLoop); for(i=0; i<nCol; i++){ int addr2 = sqlite3VdbeCurrentAddr(v) - (nCol*2); if( i==0 ){ sqlite3VdbeJumpHere(v, addr2-1); /* Set jump dest for the OP_IfNot */ } sqlite3VdbeJumpHere(v, addr2); /* Set jump dest for the OP_Ne */ sqlite3VdbeAddOp2(v, OP_AddImm, iMem+i+1, 1); sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, iMem+nCol+i+1); } /* End of the analysis loop. */ sqlite3VdbeResolveLabel(v, endOfLoop); sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop); sqlite3VdbeAddOp1(v, OP_Close, iIdxCur); /* Store the results in sqlite_stat1. ** ** The result is a single row of the sqlite_stat1 table. The first ** two columns are the names of the table and index. The third column ** is a string composed of a list of integer statistics about the ** index. The first integer in the list is the total number of entries ** in the index. There is one additional integer in the list for each ** column of the table. This additional integer is a guess of how many ** rows of the table the index will select. If D is the count of distinct ** values and K is the total number of rows, then the integer is computed ** as: ** ** I = (K+D-1)/D ** ** If K==0 then no entry is made into the sqlite_stat1 table. ** If K>0 then it is always the case the D>0 so division by zero ** is never possible. */ sqlite3VdbeAddOp2(v, OP_SCopy, iMem, regSampleno); if( jZeroRows<0 ){ jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, iMem); } for(i=0; i<nCol; i++){ sqlite3VdbeAddOp4(v, OP_String8, 0, regTemp, 0, " ", 0); sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regSampleno, regSampleno); sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp); sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1); sqlite3VdbeAddOp3(v, OP_Divide, iMem+i+1, regTemp, regTemp); sqlite3VdbeAddOp1(v, OP_ToInt, regTemp); sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regSampleno, regSampleno); } sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0); sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid); sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid); sqlite3VdbeChangeP5(v, OPFLAG_APPEND); } /* If the table has no indices, create a single sqlite_stat1 entry ** containing NULL as the index name and the row count as the content. */ if( pTab->pIndex==0 ){ sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pTab->tnum, iDb); VdbeComment((v, "%s", pTab->zName)); sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regSampleno); sqlite3VdbeAddOp1(v, OP_Close, iIdxCur); jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regSampleno); }else{ sqlite3VdbeJumpHere(v, jZeroRows); jZeroRows = sqlite3VdbeAddOp0(v, OP_Goto); } sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname); sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0); sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid); sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid); sqlite3VdbeChangeP5(v, OPFLAG_APPEND); if( pParse->nMem<regRec ) pParse->nMem = regRec; sqlite3VdbeJumpHere(v, jZeroRows); }