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Avoid unnecessary zeroing of fields in the Vdbe object when it is allocated.

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FossilOrigin-Name: 1e21bbe836539e64d24857f4faa3d12cd607dc7e
This commit is contained in:
drh
2016-10-01 00:37:50 +00:00
parent cd9af608e1
commit ab3182f7c4
4 changed files with 50 additions and 38 deletions
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55
src/vdbeInt.h
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@@ -340,34 +340,47 @@ struct ScanStatus {
*/
struct Vdbe {
sqlite3 *db; /* The database connection that owns this statement */
Vdbe *pPrev,*pNext; /* Linked list of VDBEs with the same Vdbe.db */
Parse *pParse; /* Parsing context used to create this Vdbe */
ynVar nVar; /* Number of entries in aVar[] */
ynVar nzVar; /* Number of entries in azVar[] */
u32 magic; /* Magic number for sanity checking */
int nMem; /* Number of memory locations currently allocated */
int nCursor; /* Number of slots in apCsr[] */
u32 cacheCtr; /* VdbeCursor row cache generation counter */
int pc; /* The program counter */
int rc; /* Value to return */
int nChange; /* Number of db changes made since last reset */
int iStatement; /* Statement number (or 0 if has not opened stmt) */
i64 iCurrentTime; /* Value of julianday('now') for this statement */
i64 nFkConstraint; /* Number of imm. FK constraints this VM */
i64 nStmtDefCons; /* Number of def. constraints when stmt started */
i64 nStmtDefImmCons; /* Number of def. imm constraints when stmt started */
/* When allocating a new Vdbe object, all of the fields below should be
** initialized to zero or NULL */
Op *aOp; /* Space to hold the virtual machine's program */
Mem *aMem; /* The memory locations */
Mem **apArg; /* Arguments to currently executing user function */
Mem *aColName; /* Column names to return */
Mem *pResultSet; /* Pointer to an array of results */
Parse *pParse; /* Parsing context used to create this Vdbe */
int nMem; /* Number of memory locations currently allocated */
int nOp; /* Number of instructions in the program */
int nCursor; /* Number of slots in apCsr[] */
u32 magic; /* Magic number for sanity checking */
char *zErrMsg; /* Error message written here */
Vdbe *pPrev,*pNext; /* Linked list of VDBEs with the same Vdbe.db */
VdbeCursor **apCsr; /* One element of this array for each open cursor */
Mem *aVar; /* Values for the OP_Variable opcode. */
char **azVar; /* Name of variables */
ynVar nVar; /* Number of entries in aVar[] */
ynVar nzVar; /* Number of entries in azVar[] */
u32 cacheCtr; /* VdbeCursor row cache generation counter */
int pc; /* The program counter */
int rc; /* Value to return */
#ifndef SQLITE_OMIT_TRACE
i64 startTime; /* Time when query started - used for profiling */
#endif
int nOp; /* Number of instructions in the program */
#ifdef SQLITE_DEBUG
int rcApp; /* errcode set by sqlite3_result_error_code() */
#endif
u16 nResColumn; /* Number of columns in one row of the result set */
u8 errorAction; /* Recovery action to do in case of an error */
u8 minWriteFileFormat; /* Minimum file format for writable database files */
bft expired:1; /* True if the VM needs to be recompiled */
bft doingRerun:1; /* True if rerunning after an auto-reprepare */
u8 minWriteFileFormat; /* Minimum file format for writable database files */
bft explain:2; /* True if EXPLAIN present on SQL command */
bft changeCntOn:1; /* True to update the change-counter */
bft runOnlyOnce:1; /* Automatically expire on reset */
@@ -375,18 +388,9 @@ struct Vdbe {
bft readOnly:1; /* True for statements that do not write */
bft bIsReader:1; /* True for statements that read */
bft isPrepareV2:1; /* True if prepared with prepare_v2() */
int nChange; /* Number of db changes made since last reset */
yDbMask btreeMask; /* Bitmask of db->aDb[] entries referenced */
yDbMask lockMask; /* Subset of btreeMask that requires a lock */
int iStatement; /* Statement number (or 0 if has not opened stmt) */
u32 aCounter[5]; /* Counters used by sqlite3_stmt_status() */
#ifndef SQLITE_OMIT_TRACE
i64 startTime; /* Time when query started - used for profiling */
#endif
i64 iCurrentTime; /* Value of julianday('now') for this statement */
i64 nFkConstraint; /* Number of imm. FK constraints this VM */
i64 nStmtDefCons; /* Number of def. constraints when stmt started */
i64 nStmtDefImmCons; /* Number of def. imm constraints when stmt started */
char *zSql; /* Text of the SQL statement that generated this */
void *pFree; /* Free this when deleting the vdbe */
VdbeFrame *pFrame; /* Parent frame */
@@ -405,10 +409,11 @@ struct Vdbe {
/*
** The following are allowed values for Vdbe.magic
*/
#define VDBE_MAGIC_INIT 0x26bceaa5 /* Building a VDBE program */
#define VDBE_MAGIC_RUN 0xbdf20da3 /* VDBE is ready to execute */
#define VDBE_MAGIC_HALT 0x519c2973 /* VDBE has completed execution */
#define VDBE_MAGIC_DEAD 0xb606c3c8 /* The VDBE has been deallocated */
#define VDBE_MAGIC_INIT 0x16bceaa5 /* Building a VDBE program */
#define VDBE_MAGIC_RUN 0x2df20da3 /* VDBE is ready to execute */
#define VDBE_MAGIC_HALT 0x319c2973 /* VDBE has completed execution */
#define VDBE_MAGIC_RESET 0x48fa9f76 /* Reset and ready to run again */
#define VDBE_MAGIC_DEAD 0x5606c3c8 /* The VDBE has been deallocated */
/*
** Structure used to store the context required by the