diff options
Diffstat (limited to 'src/vdbeaux.c')
-rw-r--r-- | src/vdbeaux.c | 237 |
1 files changed, 130 insertions, 107 deletions
diff --git a/src/vdbeaux.c b/src/vdbeaux.c index 0322b04c2..8181f01aa 100644 --- a/src/vdbeaux.c +++ b/src/vdbeaux.c @@ -1391,44 +1391,88 @@ static void *allocSpace( } /* -** Prepare a virtual machine for execution. This involves things such +** Rewind the VDBE back to the beginning in preparation for +** running it. +*/ +void sqlite3VdbeRewind(Vdbe *p){ +#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE) + int i; +#endif + assert( p!=0 ); + assert( p->magic==VDBE_MAGIC_INIT ); + + /* There should be at least one opcode. + */ + assert( p->nOp>0 ); + + /* Set the magic to VDBE_MAGIC_RUN sooner rather than later. */ + p->magic = VDBE_MAGIC_RUN; + +#ifdef SQLITE_DEBUG + for(i=1; i<p->nMem; i++){ + assert( p->aMem[i].db==p->db ); + } +#endif + p->pc = -1; + p->rc = SQLITE_OK; + p->errorAction = OE_Abort; + p->magic = VDBE_MAGIC_RUN; + p->nChange = 0; + p->cacheCtr = 1; + p->minWriteFileFormat = 255; + p->iStatement = 0; + p->nFkConstraint = 0; +#ifdef VDBE_PROFILE + for(i=0; i<p->nOp; i++){ + p->aOp[i].cnt = 0; + p->aOp[i].cycles = 0; + } +#endif +} + +/* +** Prepare a virtual machine for execution for the first time after +** creating the virtual machine. This involves things such ** as allocating stack space and initializing the program counter. ** After the VDBE has be prepped, it can be executed by one or more ** calls to sqlite3VdbeExec(). ** -** This is the only way to move a VDBE from VDBE_MAGIC_INIT to -** VDBE_MAGIC_RUN. +** This function may be called exact once on a each virtual machine. +** After this routine is called the VM has been "packaged" and is ready +** to run. After this routine is called, futher calls to +** sqlite3VdbeAddOp() functions are prohibited. This routine disconnects +** the Vdbe from the Parse object that helped generate it so that the +** the Vdbe becomes an independent entity and the Parse object can be +** destroyed. ** -** This function may be called more than once on a single virtual machine. -** The first call is made while compiling the SQL statement. Subsequent -** calls are made as part of the process of resetting a statement to be -** re-executed (from a call to sqlite3_reset()). The nVar, nMem, nCursor -** and isExplain parameters are only passed correct values the first time -** the function is called. On subsequent calls, from sqlite3_reset(), nVar -** is passed -1 and nMem, nCursor and isExplain are all passed zero. +** Use the sqlite3VdbeRewind() procedure to restore a virtual machine back +** to its initial state after it has been run. */ void sqlite3VdbeMakeReady( Vdbe *p, /* The VDBE */ - int nVar, /* Number of '?' see in the SQL statement */ - int nMem, /* Number of memory cells to allocate */ - int nCursor, /* Number of cursors to allocate */ - int nArg, /* Maximum number of args in SubPrograms */ - int isExplain, /* True if the EXPLAIN keywords is present */ - int usesStmtJournal /* True to set Vdbe.usesStmtJournal */ + Parse *pParse /* Parsing context */ ){ - int n; - sqlite3 *db = p->db; + sqlite3 *db; /* The database connection */ + int nVar; /* Number of parameters */ + int nMem; /* Number of VM memory registers */ + int nCursor; /* Number of cursors required */ + int nArg; /* Number of arguments in subprograms */ + int n; /* Loop counter */ + u8 *zCsr; /* Memory available for allocation */ + u8 *zEnd; /* First byte past allocated memory */ + int nByte; /* How much extra memory is needed */ assert( p!=0 ); - assert( p->magic==VDBE_MAGIC_INIT ); - - /* There should be at least one opcode. - */ assert( p->nOp>0 ); - - /* Set the magic to VDBE_MAGIC_RUN sooner rather than later. */ - p->magic = VDBE_MAGIC_RUN; - + assert( pParse!=0 ); + assert( p->magic==VDBE_MAGIC_INIT ); + db = p->db; + assert( db->mallocFailed==0 ); + nVar = pParse->nVar; + nMem = pParse->nMem; + nCursor = pParse->nTab; + nArg = pParse->nMaxArg; + /* For each cursor required, also allocate a memory cell. Memory ** cells (nMem+1-nCursor)..nMem, inclusive, will never be used by ** the vdbe program. Instead they are used to allocate space for @@ -1441,91 +1485,68 @@ void sqlite3VdbeMakeReady( nMem += nCursor; /* Allocate space for memory registers, SQL variables, VDBE cursors and - ** an array to marshal SQL function arguments in. This is only done the - ** first time this function is called for a given VDBE, not when it is - ** being called from sqlite3_reset() to reset the virtual machine. + ** an array to marshal SQL function arguments in. */ - if( nVar>=0 && ALWAYS(db->mallocFailed==0) ){ - u8 *zCsr = (u8 *)&p->aOp[p->nOp]; /* Memory avaliable for alloation */ - u8 *zEnd = (u8 *)&p->aOp[p->nOpAlloc]; /* First byte past available mem */ - int nByte; /* How much extra memory needed */ - - resolveP2Values(p, &nArg); - p->usesStmtJournal = (u8)usesStmtJournal; - if( isExplain && nMem<10 ){ - nMem = 10; - } - memset(zCsr, 0, zEnd-zCsr); - zCsr += (zCsr - (u8*)0)&7; - assert( EIGHT_BYTE_ALIGNMENT(zCsr) ); - - /* Memory for registers, parameters, cursor, etc, is allocated in two - ** passes. On the first pass, we try to reuse unused space at the - ** end of the opcode array. If we are unable to satisfy all memory - ** requirements by reusing the opcode array tail, then the second - ** pass will fill in the rest using a fresh allocation. - ** - ** This two-pass approach that reuses as much memory as possible from - ** the leftover space at the end of the opcode array can significantly - ** reduce the amount of memory held by a prepared statement. - */ - do { - nByte = 0; - p->aMem = allocSpace(p->aMem, nMem*sizeof(Mem), &zCsr, zEnd, &nByte); - p->aVar = allocSpace(p->aVar, nVar*sizeof(Mem), &zCsr, zEnd, &nByte); - p->apArg = allocSpace(p->apArg, nArg*sizeof(Mem*), &zCsr, zEnd, &nByte); - p->azVar = allocSpace(p->azVar, nVar*sizeof(char*), &zCsr, zEnd, &nByte); - p->apCsr = allocSpace(p->apCsr, nCursor*sizeof(VdbeCursor*), - &zCsr, zEnd, &nByte); - if( nByte ){ - p->pFree = sqlite3DbMallocZero(db, nByte); - } - zCsr = p->pFree; - zEnd = &zCsr[nByte]; - }while( nByte && !db->mallocFailed ); - - p->nCursor = (u16)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; - } - } - if( p->aMem ){ - p->aMem--; /* aMem[] goes from 1..nMem */ - p->nMem = nMem; /* not from 0..nMem-1 */ - for(n=1; n<=nMem; n++){ - p->aMem[n].flags = MEM_Null; - p->aMem[n].db = db; - } - } - } -#ifdef SQLITE_DEBUG - for(n=1; n<p->nMem; n++){ - assert( p->aMem[n].db==db ); + zCsr = (u8*)&p->aOp[p->nOp]; /* Memory avaliable for allocation */ + zEnd = (u8*)&p->aOp[p->nOpAlloc]; /* First byte past end of zCsr[] */ + + resolveP2Values(p, &nArg); + p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort); + if( pParse->explain && nMem<10 ){ + nMem = 10; + } + memset(zCsr, 0, zEnd-zCsr); + zCsr += (zCsr - (u8*)0)&7; + assert( EIGHT_BYTE_ALIGNMENT(zCsr) ); + + /* Memory for registers, parameters, cursor, etc, is allocated in two + ** passes. On the first pass, we try to reuse unused space at the + ** end of the opcode array. If we are unable to satisfy all memory + ** requirements by reusing the opcode array tail, then the second + ** pass will fill in the rest using a fresh allocation. + ** + ** This two-pass approach that reuses as much memory as possible from + ** the leftover space at the end of the opcode array can significantly + ** reduce the amount of memory held by a prepared statement. + */ + do { + nByte = 0; + p->aMem = allocSpace(p->aMem, nMem*sizeof(Mem), &zCsr, zEnd, &nByte); + p->aVar = allocSpace(p->aVar, nVar*sizeof(Mem), &zCsr, zEnd, &nByte); + p->apArg = allocSpace(p->apArg, nArg*sizeof(Mem*), &zCsr, zEnd, &nByte); + p->azVar = allocSpace(p->azVar, nVar*sizeof(char*), &zCsr, zEnd, &nByte); + p->apCsr = allocSpace(p->apCsr, nCursor*sizeof(VdbeCursor*), + &zCsr, zEnd, &nByte); + if( nByte ){ + p->pFree = sqlite3DbMallocZero(db, nByte); + } + zCsr = p->pFree; + zEnd = &zCsr[nByte]; + }while( nByte && !db->mallocFailed ); + + p->nCursor = (u16)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; + } + } + if( p->azVar ){ + p->nzVar = pParse->nzVar; + memcpy(p->azVar, pParse->azVar, p->nzVar*sizeof(p->azVar[0])); + memset(pParse->azVar, 0, pParse->nzVar*sizeof(pParse->azVar[0])); } -#endif - - p->pc = -1; - p->rc = SQLITE_OK; - p->errorAction = OE_Abort; - p->explain |= isExplain; - p->magic = VDBE_MAGIC_RUN; - p->nChange = 0; - p->cacheCtr = 1; - p->minWriteFileFormat = 255; - p->iStatement = 0; - p->nFkConstraint = 0; -#ifdef VDBE_PROFILE - { - int i; - for(i=0; i<p->nOp; i++){ - p->aOp[i].cnt = 0; - p->aOp[i].cycles = 0; + if( p->aMem ){ + p->aMem--; /* aMem[] goes from 1..nMem */ + p->nMem = nMem; /* not from 0..nMem-1 */ + for(n=1; n<=nMem; n++){ + p->aMem[n].flags = MEM_Null; + p->aMem[n].db = db; } } -#endif + p->explain = pParse->explain; + sqlite3VdbeRewind(p); } /* @@ -2399,6 +2420,7 @@ void sqlite3VdbeDeleteAuxData(VdbeFunc *pVdbeFunc, int mask){ */ void sqlite3VdbeDeleteObject(sqlite3 *db, Vdbe *p){ SubProgram *pSub, *pNext; + int i; assert( p->db==0 || p->db==db ); releaseMemArray(p->aVar, p->nVar); releaseMemArray(p->aColName, p->nResColumn*COLNAME_N); @@ -2407,6 +2429,7 @@ void sqlite3VdbeDeleteObject(sqlite3 *db, Vdbe *p){ vdbeFreeOpArray(db, pSub->aOp, pSub->nOp); sqlite3DbFree(db, pSub); } + for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]); vdbeFreeOpArray(db, p->aOp, p->nOp); sqlite3DbFree(db, p->aLabel); sqlite3DbFree(db, p->aColName); |