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chromium/external/github.com/pwnall/sqlite/refs/heads/branch_3_2/./src/vdbe.c
blob: d7af8f0210c5ca4c5163e0d94f942807b9be0da9 [file] [edit]
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** The code in this file implements execution method of the
** Virtual Database Engine (VDBE). A separate file ("vdbeaux.c")
** handles housekeeping details such as creating and deleting
** VDBE instances. This file is solely interested in executing
** the VDBE program.
**
** In the external interface, an "sqlite3_stmt*" is an opaque pointer
** to a VDBE.
**
** The SQL parser generates a program which is then executed by
** the VDBE to do the work of the SQL statement. VDBE programs are
** similar in form to assembly language. The program consists of
** a linear sequence of operations. Each operation has an opcode
** and 3 operands. Operands P1 and P2 are integers. Operand P3
** is a null-terminated string. The P2 operand must be non-negative.
** Opcodes will typically ignore one or more operands. Many opcodes
** ignore all three operands.
**
** Computation results are stored on a stack. Each entry on the
** stack is either an integer, a null-terminated string, a floating point
** number, or the SQL "NULL" value. An inplicit conversion from one
** type to the other occurs as necessary.
**
** Most of the code in this file is taken up by the sqlite3VdbeExec()
** function which does the work of interpreting a VDBE program.
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files. The formatting
** of the code in this file is, therefore, important. See other comments
** in this file for details. If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.491 2005/09/20 17:42:23 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"
/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_MoveXX, OP_Next, or OP_Prev opcodes. The test
** procedures use this information to make sure that indices are
** working correctly. This variable has no function other than to
** help verify the correct operation of the library.
*/
int sqlite3_search_count = 0;
/*
** When this global variable is positive, it gets decremented once before
** each instruction in the VDBE. When reaches zero, the SQLITE_Interrupt
** of the db.flags field is set in order to simulate and interrupt.
**
** This facility is used for testing purposes only. It does not function
** in an ordinary build.
*/
int sqlite3_interrupt_count = 0;
/*
** The next global variable is incremented each type the OP_Sort opcode
** is executed. The test procedures use this information to make sure that
** sorting is occurring or not occuring at appropriate times. This variable
** has no function other than to help verify the correct operation of the
** library.
*/
int sqlite3_sort_count = 0;
/*
** Release the memory associated with the given stack level. This
** leaves the Mem.flags field in an inconsistent state.
*/
#define Release(P) if((P)->flags&MEM_Dyn){ sqlite3VdbeMemRelease(P); }
/*
** Convert the given stack entity into a string if it isn't one
** already. Return non-zero if a malloc() fails.
*/
#define Stringify(P, enc) \
if(((P)->flags&(MEM_Str|MEM_Blob))==0 && sqlite3VdbeMemStringify(P,enc)) \
{ goto no_mem; }
/*
** Convert the given stack entity into a string that has been obtained
** from sqliteMalloc(). This is different from Stringify() above in that
** Stringify() will use the NBFS bytes of static string space if the string
** will fit but this routine always mallocs for space.
** Return non-zero if we run out of memory.
*/
#define Dynamicify(P,enc) sqlite3VdbeMemDynamicify(P)
/*
** An ephemeral string value (signified by the MEM_Ephem flag) contains
** a pointer to a dynamically allocated string where some other entity
** is responsible for deallocating that string. Because the stack entry
** does not control the string, it might be deleted without the stack
** entry knowing it.
**
** This routine converts an ephemeral string into a dynamically allocated
** string that the stack entry itself controls. In other words, it
** converts an MEM_Ephem string into an MEM_Dyn string.
*/
#define Deephemeralize(P) \
if( ((P)->flags&MEM_Ephem)!=0 \
&& sqlite3VdbeMemMakeWriteable(P) ){ goto no_mem;}
/*
** Convert the given stack entity into a integer if it isn't one
** already.
**
** Any prior string or real representation is invalidated.
** NULLs are converted into 0.
*/
#define Integerify(P) sqlite3VdbeMemIntegerify(P)
/*
** Convert P so that it has type MEM_Real.
**
** Any prior string or integer representation is invalidated.
** NULLs are converted into 0.0.
*/
#define Realify(P) sqlite3VdbeMemRealify(P)
/*
** Argument pMem points at a memory cell that will be passed to a
** user-defined function or returned to the user as the result of a query.
** The second argument, 'db_enc' is the text encoding used by the vdbe for
** stack variables. This routine sets the pMem->enc and pMem->type
** variables used by the sqlite3_value_*() routines.
*/
#define storeTypeInfo(A,B) _storeTypeInfo(A)
static void _storeTypeInfo(Mem *pMem){
int flags = pMem->flags;
if( flags & MEM_Null ){
pMem->type = SQLITE_NULL;
}
else if( flags & MEM_Int ){
pMem->type = SQLITE_INTEGER;
}
else if( flags & MEM_Real ){
pMem->type = SQLITE_FLOAT;
}
else if( flags & MEM_Str ){
pMem->type = SQLITE_TEXT;
}else{
pMem->type = SQLITE_BLOB;
}
}
/*
** Pop the stack N times.
*/
static void popStack(Mem **ppTos, int N){
Mem *pTos = *ppTos;
while( N>0 ){
N--;
Release(pTos);
pTos--;
}
*ppTos = pTos;
}
/*
** Allocate cursor number iCur. Return a pointer to it. Return NULL
** if we run out of memory.
*/
static Cursor *allocateCursor(Vdbe *p, int iCur){
Cursor *pCx;
assert( iCur<p->nCursor );
if( p->apCsr[iCur] ){
sqlite3VdbeFreeCursor(p->apCsr[iCur]);
}
p->apCsr[iCur] = pCx = sqliteMalloc( sizeof(Cursor) );
return pCx;
}
/*
** Apply any conversion required by the supplied column affinity to
** memory cell pRec. affinity may be one of:
**
** SQLITE_AFF_NUMERIC
** SQLITE_AFF_TEXT
** SQLITE_AFF_NONE
** SQLITE_AFF_INTEGER
**
*/
static void applyAffinity(Mem *pRec, char affinity, u8 enc){
if( affinity==SQLITE_AFF_NONE ){
/* do nothing */
}else if( affinity==SQLITE_AFF_TEXT ){
/* Only attempt the conversion to TEXT if there is an integer or real
** representation (blob and NULL do not get converted) but no string
** representation.
*/
if( 0==(pRec->flags&MEM_Str) && (pRec->flags&(MEM_Real|MEM_Int)) ){
sqlite3VdbeMemStringify(pRec, enc);
}
pRec->flags &= ~(MEM_Real|MEM_Int);
}else{
if( 0==(pRec->flags&(MEM_Real|MEM_Int)) ){
/* pRec does not have a valid integer or real representation.
** Attempt a conversion if pRec has a string representation and
** it looks like a number.
*/
int realnum;
sqlite3VdbeMemNulTerminate(pRec);
if( pRec->flags&MEM_Str && sqlite3IsNumber(pRec->z, &realnum, enc) ){
if( realnum ){
Realify(pRec);
}else{
Integerify(pRec);
}
}
}
if( affinity==SQLITE_AFF_INTEGER ){
/* For INTEGER affinity, try to convert a real value to an int */
if( (pRec->flags&MEM_Real) && !(pRec->flags&MEM_Int) ){
pRec->i = pRec->r;
if( ((double)pRec->i)==pRec->r ){
pRec->flags |= MEM_Int;
}
}
}
}
}
/*
** Exported version of applyAffinity(). This one works on sqlite3_value*,
** not the internal Mem* type.
*/
void sqlite3ValueApplyAffinity(sqlite3_value *pVal, u8 affinity, u8 enc){
applyAffinity((Mem *)pVal, affinity, enc);
}
#ifdef SQLITE_DEBUG
/*
** Write a nice string representation of the contents of cell pMem
** into buffer zBuf, length nBuf.
*/
void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf, int nBuf){
char *zCsr = zBuf;
int f = pMem->flags;
static const char *const encnames[] = {"(X)", "(8)", "(16LE)", "(16BE)"};
if( f&MEM_Blob ){
int i;
char c;
if( f & MEM_Dyn ){
c = 'z';
assert( (f & (MEM_Static|MEM_Ephem))==0 );
}else if( f & MEM_Static ){
c = 't';
assert( (f & (MEM_Dyn|MEM_Ephem))==0 );
}else if( f & MEM_Ephem ){
c = 'e';
assert( (f & (MEM_Static|MEM_Dyn))==0 );
}else{
c = 's';
}
zCsr += sprintf(zCsr, "%c", c);
zCsr += sprintf(zCsr, "%d[", pMem->n);
for(i=0; i<16 && i<pMem->n; i++){
zCsr += sprintf(zCsr, "%02X ", ((int)pMem->z[i] & 0xFF));
}
for(i=0; i<16 && i<pMem->n; i++){
char z = pMem->z[i];
if( z<32 || z>126 ) *zCsr++ = '.';
else *zCsr++ = z;
}
zCsr += sprintf(zCsr, "]");
*zCsr = '\0';
}else if( f & MEM_Str ){
int j, k;
zBuf[0] = ' ';
if( f & MEM_Dyn ){
zBuf[1] = 'z';
assert( (f & (MEM_Static|MEM_Ephem))==0 );
}else if( f & MEM_Static ){
zBuf[1] = 't';
assert( (f & (MEM_Dyn|MEM_Ephem))==0 );
}else if( f & MEM_Ephem ){
zBuf[1] = 'e';
assert( (f & (MEM_Static|MEM_Dyn))==0 );
}else{
zBuf[1] = 's';
}
k = 2;
k += sprintf(&zBuf[k], "%d", pMem->n);
zBuf[k++] = '[';
for(j=0; j<15 && j<pMem->n; j++){
u8 c = pMem->z[j];
if( c>=0x20 && c<0x7f ){
zBuf[k++] = c;
}else{
zBuf[k++] = '.';
}
}
zBuf[k++] = ']';
k += sprintf(&zBuf[k], encnames[pMem->enc]);
zBuf[k++] = 0;
}
}
#endif
#ifdef VDBE_PROFILE
/*
** The following routine only works on pentium-class processors.
** It uses the RDTSC opcode to read the cycle count value out of the
** processor and returns that value. This can be used for high-res
** profiling.
*/
__inline__ unsigned long long int hwtime(void){
unsigned long long int x;
__asm__("rdtsc\n\t"
"mov %%edx, %%ecx\n\t"
:"=A" (x));
return x;
}
#endif
/*
** The CHECK_FOR_INTERRUPT macro defined here looks to see if the
** sqlite3_interrupt() routine has been called. If it has been, then
** processing of the VDBE program is interrupted.
**
** This macro added to every instruction that does a jump in order to
** implement a loop. This test used to be on every single instruction,
** but that meant we more testing that we needed. By only testing the
** flag on jump instructions, we get a (small) speed improvement.
*/
#define CHECK_FOR_INTERRUPT \
if( db->flags & SQLITE_Interrupt ) goto abort_due_to_interrupt;
/*
** Execute as much of a VDBE program as we can then return.
**
** sqlite3VdbeMakeReady() must be called before this routine in order to
** close the program with a final OP_Halt and to set up the callbacks
** and the error message pointer.
**
** Whenever a row or result data is available, this routine will either
** invoke the result callback (if there is one) or return with
** SQLITE_ROW.
**
** If an attempt is made to open a locked database, then this routine
** will either invoke the busy callback (if there is one) or it will
** return SQLITE_BUSY.
**
** If an error occurs, an error message is written to memory obtained
** from sqliteMalloc() and p->zErrMsg is made to point to that memory.
** The error code is stored in p->rc and this routine returns SQLITE_ERROR.
**
** If the callback ever returns non-zero, then the program exits
** immediately. There will be no error message but the p->rc field is
** set to SQLITE_ABORT and this routine will return SQLITE_ERROR.
**
** A memory allocation error causes p->rc to be set to SQLITE_NOMEM and this
** routine to return SQLITE_ERROR.
**
** Other fatal errors return SQLITE_ERROR.
**
** After this routine has finished, sqlite3VdbeFinalize() should be
** used to clean up the mess that was left behind.
*/
int sqlite3VdbeExec(
Vdbe *p /* The VDBE */
){
int pc; /* The program counter */
Op *pOp; /* Current operation */
int rc = SQLITE_OK; /* Value to return */
sqlite3 *db = p->db; /* The database */
Mem *pTos; /* Top entry in the operand stack */
#ifdef VDBE_PROFILE
unsigned long long start; /* CPU clock count at start of opcode */
int origPc; /* Program counter at start of opcode */
#endif
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
int nProgressOps = 0; /* Opcodes executed since progress callback. */
#endif
#ifndef NDEBUG
Mem *pStackLimit;
#endif
if( p->magic!=VDBE_MAGIC_RUN ) return SQLITE_MISUSE;
assert( db->magic==SQLITE_MAGIC_BUSY );
assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY );
p->rc = SQLITE_OK;
assert( p->explain==0 );
pTos = p->pTos;
if( sqlite3_malloc_failed ) goto no_mem;
if( p->popStack ){
popStack(&pTos, p->popStack);
p->popStack = 0;
}
p->resOnStack = 0;
db->busyHandler.nBusy = 0;
CHECK_FOR_INTERRUPT;
for(pc=p->pc; rc==SQLITE_OK; pc++){
assert( pc>=0 && pc<p->nOp );
assert( pTos<=&p->aStack[pc] );
if( sqlite3_malloc_failed ) goto no_mem;
#ifdef VDBE_PROFILE
origPc = pc;
start = hwtime();
#endif
pOp = &p->aOp[pc];
/* Only allow tracing if SQLITE_DEBUG is defined.
*/
#ifdef SQLITE_DEBUG
if( p->trace ){
if( pc==0 ){
printf("VDBE Execution Trace:\n");
sqlite3VdbePrintSql(p);
}
sqlite3VdbePrintOp(p->trace, pc, pOp);
}
if( p->trace==0 && pc==0 && sqlite3OsFileExists("vdbe_sqltrace") ){
sqlite3VdbePrintSql(p);
}
#endif
/* Check to see if we need to simulate an interrupt. This only happens
** if we have a special test build.
*/
#ifdef SQLITE_TEST
if( sqlite3_interrupt_count>0 ){
sqlite3_interrupt_count--;
if( sqlite3_interrupt_count==0 ){
sqlite3_interrupt(db);
}
}
#endif
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
/* Call the progress callback if it is configured and the required number
** of VDBE ops have been executed (either since this invocation of
** sqlite3VdbeExec() or since last time the progress callback was called).
** If the progress callback returns non-zero, exit the virtual machine with
** a return code SQLITE_ABORT.
*/
if( db->xProgress ){
if( db->nProgressOps==nProgressOps ){
if( db->xProgress(db->pProgressArg)!=0 ){
rc = SQLITE_ABORT;
continue; /* skip to the next iteration of the for loop */
}
nProgressOps = 0;
}
nProgressOps++;
}
#endif
#ifndef NDEBUG
/* This is to check that the return value of static function
** opcodeNoPush() (see vdbeaux.c) returns values that match the
** implementation of the virtual machine in this file. If
** opcodeNoPush() returns non-zero, then the stack is guarenteed
** not to grow when the opcode is executed. If it returns zero, then
** the stack may grow by at most 1.
**
** The global wrapper function sqlite3VdbeOpcodeUsesStack() is not
** available if NDEBUG is defined at build time.
*/
pStackLimit = pTos;
if( !sqlite3VdbeOpcodeNoPush(pOp->opcode) ){
pStackLimit++;
}
#endif
switch( pOp->opcode ){
/*****************************************************************************
** What follows is a massive switch statement where each case implements a
** separate instruction in the virtual machine. If we follow the usual
** indentation conventions, each case should be indented by 6 spaces. But
** that is a lot of wasted space on the left margin. So the code within
** the switch statement will break with convention and be flush-left. Another
** big comment (similar to this one) will mark the point in the code where
** we transition back to normal indentation.
**
** The formatting of each case is important. The makefile for SQLite
** generates two C files "opcodes.h" and "opcodes.c" by scanning this
** file looking for lines that begin with "case OP_". The opcodes.h files
** will be filled with #defines that give unique integer values to each
** opcode and the opcodes.c file is filled with an array of strings where
** each string is the symbolic name for the corresponding opcode. If the
** case statement is followed by a comment of the form "/# same as ... #/"
** that comment is used to determine the particular value of the opcode.
**
** If a comment on the same line as the "case OP_" construction contains
** the word "no-push", then the opcode is guarenteed not to grow the
** vdbe stack when it is executed. See function opcode() in
** vdbeaux.c for details.
**
** Documentation about VDBE opcodes is generated by scanning this file
** for lines of that contain "Opcode:". That line and all subsequent
** comment lines are used in the generation of the opcode.html documentation
** file.
**
** SUMMARY:
**
** Formatting is important to scripts that scan this file.
** Do not deviate from the formatting style currently in use.
**
*****************************************************************************/
/* Opcode: Goto * P2 *
**
** An unconditional jump to address P2.
** The next instruction executed will be
** the one at index P2 from the beginning of
** the program.
*/
case OP_Goto: { /* no-push */
CHECK_FOR_INTERRUPT;
pc = pOp->p2 - 1;
break;
}
/* Opcode: Gosub * P2 *
**
** Push the current address plus 1 onto the return address stack
** and then jump to address P2.
**
** The return address stack is of limited depth. If too many
** OP_Gosub operations occur without intervening OP_Returns, then
** the return address stack will fill up and processing will abort
** with a fatal error.
*/
case OP_Gosub: { /* no-push */
assert( p->returnDepth<sizeof(p->returnStack)/sizeof(p->returnStack[0]) );
p->returnStack[p->returnDepth++] = pc+1;
pc = pOp->p2 - 1;
break;
}
/* Opcode: Return * * *
**
** Jump immediately to the next instruction after the last unreturned
** OP_Gosub. If an OP_Return has occurred for all OP_Gosubs, then
** processing aborts with a fatal error.
*/
case OP_Return: { /* no-push */
assert( p->returnDepth>0 );
p->returnDepth--;
pc = p->returnStack[p->returnDepth] - 1;
break;
}
/* Opcode: Halt P1 P2 P3
**
** Exit immediately. All open cursors, Fifos, etc are closed
** automatically.
**
** P1 is the result code returned by sqlite3_exec(), sqlite3_reset(),
** or sqlite3_finalize(). For a normal halt, this should be SQLITE_OK (0).
** For errors, it can be some other value. If P1!=0 then P2 will determine
** whether or not to rollback the current transaction. Do not rollback
** if P2==OE_Fail. Do the rollback if P2==OE_Rollback. If P2==OE_Abort,
** then back out all changes that have occurred during this execution of the
** VDBE, but do not rollback the transaction.
**
** If P3 is not null then it is an error message string.
**
** There is an implied "Halt 0 0 0" instruction inserted at the very end of
** every program. So a jump past the last instruction of the program
** is the same as executing Halt.
*/
case OP_Halt: { /* no-push */
p->pTos = pTos;
p->rc = pOp->p1;
p->pc = pc;
p->errorAction = pOp->p2;
if( pOp->p3 ){
sqlite3SetString(&p->zErrMsg, pOp->p3, (char*)0);
}
rc = sqlite3VdbeHalt(p);
assert( rc==SQLITE_BUSY || rc==SQLITE_OK );
if( rc==SQLITE_BUSY ){
p->rc = SQLITE_BUSY;
return SQLITE_BUSY;
}
return p->rc ? SQLITE_ERROR : SQLITE_DONE;
}
/* Opcode: Integer P1 * *
**
** The 32-bit integer value P1 is pushed onto the stack.
*/
case OP_Integer: {
pTos++;
pTos->flags = MEM_Int;
pTos->i = pOp->p1;
break;
}
/* Opcode: Int64 * * P3
**
** P3 is a string representation of an integer. Convert that integer
** to a 64-bit value and push it onto the stack.
*/
case OP_Int64: {
pTos++;
assert( pOp->p3!=0 );
pTos->flags = MEM_Str|MEM_Static|MEM_Term;
pTos->z = pOp->p3;
pTos->n = strlen(pTos->z);
pTos->enc = SQLITE_UTF8;
pTos->i = sqlite3VdbeIntValue(pTos);
pTos->flags |= MEM_Int;
break;
}
/* Opcode: Real * * P3
**
** The string value P3 is converted to a real and pushed on to the stack.
*/
case OP_Real: { /* same as TK_FLOAT, */
pTos++;
pTos->flags = MEM_Str|MEM_Static|MEM_Term;
pTos->z = pOp->p3;
pTos->n = strlen(pTos->z);
pTos->enc = SQLITE_UTF8;
pTos->r = sqlite3VdbeRealValue(pTos);
pTos->flags |= MEM_Real;
sqlite3VdbeChangeEncoding(pTos, db->enc);
break;
}
/* Opcode: String8 * * P3
**
** P3 points to a nul terminated UTF-8 string. This opcode is transformed
** into an OP_String before it is executed for the first time.
*/
case OP_String8: { /* same as TK_STRING */
#ifndef SQLITE_OMIT_UTF16
pOp->opcode = OP_String;
assert( pOp->p3!=0 );
if( db->enc!=SQLITE_UTF8 ){
pTos++;
sqlite3VdbeMemSetStr(pTos, pOp->p3, -1, SQLITE_UTF8, SQLITE_STATIC);
if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pTos, db->enc) ) goto no_mem;
if( SQLITE_OK!=sqlite3VdbeMemDynamicify(pTos) ) goto no_mem;
pTos->flags &= ~(MEM_Dyn);
pTos->flags |= MEM_Static;
if( pOp->p3type==P3_DYNAMIC ){
sqliteFree(pOp->p3);
}
pOp->p3type = P3_DYNAMIC;
pOp->p3 = pTos->z;
break;
}
#endif
/* Otherwise fall through to the next case, OP_String */
}
/* Opcode: String * * P3
**
** The string value P3 is pushed onto the stack. If P3==0 then a
** NULL is pushed onto the stack. P3 is assumed to be a nul terminated
** string encoded with the database native encoding.
*/
case OP_String: {
pTos++;
assert( pOp->p3!=0 );
pTos->flags = MEM_Str|MEM_Static|MEM_Term;
pTos->z = pOp->p3;
#ifndef SQLITE_OMIT_UTF16
if( db->enc==SQLITE_UTF8 ){
pTos->n = strlen(pTos->z);
}else{
pTos->n = sqlite3utf16ByteLen(pTos->z, -1);
}
#else
assert( db->enc==SQLITE_UTF8 );
pTos->n = strlen(pTos->z);
#endif
pTos->enc = db->enc;
break;
}
/* Opcode: Null * * *
**
** Push a NULL onto the stack.
*/
case OP_Null: {
pTos++;
pTos->flags = MEM_Null;
pTos->n = 0;
break;
}
#ifndef SQLITE_OMIT_BLOB_LITERAL
/* Opcode: HexBlob * * P3
**
** P3 is an UTF-8 SQL hex encoding of a blob. The blob is pushed onto the
** vdbe stack.
**
** The first time this instruction executes, in transforms itself into a
** 'Blob' opcode with a binary blob as P3.
*/
case OP_HexBlob: { /* same as TK_BLOB */
pOp->opcode = OP_Blob;
pOp->p1 = strlen(pOp->p3)/2;
if( pOp->p1 ){
char *zBlob = sqlite3HexToBlob(pOp->p3);
if( !zBlob ) goto no_mem;
if( pOp->p3type==P3_DYNAMIC ){
sqliteFree(pOp->p3);
}
pOp->p3 = zBlob;
pOp->p3type = P3_DYNAMIC;
}else{
if( pOp->p3type==P3_DYNAMIC ){
sqliteFree(pOp->p3);
}
pOp->p3type = P3_STATIC;
pOp->p3 = "";
}
/* Fall through to the next case, OP_Blob. */
}
/* Opcode: Blob P1 * P3
**
** P3 points to a blob of data P1 bytes long. Push this
** value onto the stack. This instruction is not coded directly
** by the compiler. Instead, the compiler layer specifies
** an OP_HexBlob opcode, with the hex string representation of
** the blob as P3. This opcode is transformed to an OP_Blob
** the first time it is executed.
*/
case OP_Blob: {
pTos++;
sqlite3VdbeMemSetStr(pTos, pOp->p3, pOp->p1, 0, 0);
break;
}
#endif /* SQLITE_OMIT_BLOB_LITERAL */
/* Opcode: Variable P1 * *
**
** Push the value of variable P1 onto the stack. A variable is
** an unknown in the original SQL string as handed to sqlite3_compile().
** Any occurance of the '?' character in the original SQL is considered
** a variable. Variables in the SQL string are number from left to
** right beginning with 1. The values of variables are set using the
** sqlite3_bind() API.
*/
case OP_Variable: {
int j = pOp->p1 - 1;
assert( j>=0 && j<p->nVar );
pTos++;
sqlite3VdbeMemShallowCopy(pTos, &p->aVar[j], MEM_Static);
break;
}
/* Opcode: Pop P1 * *
**
** P1 elements are popped off of the top of stack and discarded.
*/
case OP_Pop: { /* no-push */
assert( pOp->p1>=0 );
popStack(&pTos, pOp->p1);
assert( pTos>=&p->aStack[-1] );
break;
}
/* Opcode: Dup P1 P2 *
**
** A copy of the P1-th element of the stack
** is made and pushed onto the top of the stack.
** The top of the stack is element 0. So the
** instruction "Dup 0 0 0" will make a copy of the
** top of the stack.
**
** If the content of the P1-th element is a dynamically
** allocated string, then a new copy of that string
** is made if P2==0. If P2!=0, then just a pointer
** to the string is copied.
**
** Also see the Pull instruction.
*/
case OP_Dup: {
Mem *pFrom = &pTos[-pOp->p1];
assert( pFrom<=pTos && pFrom>=p->aStack );
pTos++;
sqlite3VdbeMemShallowCopy(pTos, pFrom, MEM_Ephem);
if( pOp->p2 ){
Deephemeralize(pTos);
}
break;
}
/* Opcode: Pull P1 * *
**
** The P1-th element is removed from its current location on
** the stack and pushed back on top of the stack. The
** top of the stack is element 0, so "Pull 0 0 0" is
** a no-op. "Pull 1 0 0" swaps the top two elements of
** the stack.
**
** See also the Dup instruction.
*/
case OP_Pull: { /* no-push */
Mem *pFrom = &pTos[-pOp->p1];
int i;
Mem ts;
ts = *pFrom;
Deephemeralize(pTos);
for(i=0; i<pOp->p1; i++, pFrom++){
Deephemeralize(&pFrom[1]);
assert( (pFrom->flags & MEM_Ephem)==0 );
*pFrom = pFrom[1];
if( pFrom->flags & MEM_Short ){
assert( pFrom->flags & (MEM_Str|MEM_Blob) );
assert( pFrom->z==pFrom[1].zShort );
pFrom->z = pFrom->zShort;
}
}
*pTos = ts;
if( pTos->flags & MEM_Short ){
assert( pTos->flags & (MEM_Str|MEM_Blob) );
assert( pTos->z==pTos[-pOp->p1].zShort );
pTos->z = pTos->zShort;
}
break;
}
/* Opcode: Push P1 * *
**
** Overwrite the value of the P1-th element down on the
** stack (P1==0 is the top of the stack) with the value
** of the top of the stack. Then pop the top of the stack.
*/
case OP_Push: { /* no-push */
Mem *pTo = &pTos[-pOp->p1];
assert( pTo>=p->aStack );
sqlite3VdbeMemMove(pTo, pTos);
pTos--;
break;
}
/* Opcode: Callback P1 * *
**
** Pop P1 values off the stack and form them into an array. Then
** invoke the callback function using the newly formed array as the
** 3rd parameter.
*/
case OP_Callback: { /* no-push */
int i;
assert( p->nResColumn==pOp->p1 );
for(i=0; i<pOp->p1; i++){
Mem *pVal = &pTos[0-i];
sqlite3VdbeMemNulTerminate(pVal);
storeTypeInfo(pVal, db->enc);
}
p->resOnStack = 1;
p->nCallback++;
p->popStack = pOp->p1;
p->pc = pc + 1;
p->pTos = pTos;
return SQLITE_ROW;
}
/* Opcode: Concat P1 P2 *
**
** Look at the first P1+2 elements of the stack. Append them all
** together with the lowest element first. The original P1+2 elements
** are popped from the stack if P2==0 and retained if P2==1. If
** any element of the stack is NULL, then the result is NULL.
**
** When P1==1, this routine makes a copy of the top stack element
** into memory obtained from sqliteMalloc().
*/
case OP_Concat: { /* same as TK_CONCAT */
char *zNew;
int nByte;
int nField;
int i, j;
Mem *pTerm;
/* Loop through the stack elements to see how long the result will be. */
nField = pOp->p1 + 2;
pTerm = &pTos[1-nField];
nByte = 0;
for(i=0; i<nField; i++, pTerm++){
assert( pOp->p2==0 || (pTerm->flags&MEM_Str) );
if( pTerm->flags&MEM_Null ){
nByte = -1;
break;
}
Stringify(pTerm, db->enc);
nByte += pTerm->n;
}
if( nByte<0 ){
/* If nByte is less than zero, then there is a NULL value on the stack.
** In this case just pop the values off the stack (if required) and
** push on a NULL.
*/
if( pOp->p2==0 ){
popStack(&pTos, nField);
}
pTos++;
pTos->flags = MEM_Null;
}else{
/* Otherwise malloc() space for the result and concatenate all the
** stack values.
*/
zNew = sqliteMallocRaw( nByte+2 );
if( zNew==0 ) goto no_mem;
j = 0;
pTerm = &pTos[1-nField];
for(i=j=0; i<nField; i++, pTerm++){
int n = pTerm->n;
assert( pTerm->flags & (MEM_Str|MEM_Blob) );
memcpy(&zNew[j], pTerm->z, n);
j += n;
}
zNew[j] = 0;
zNew[j+1] = 0;
assert( j==nByte );
if( pOp->p2==0 ){
popStack(&pTos, nField);
}
pTos++;
pTos->n = j;
pTos->flags = MEM_Str|MEM_Dyn|MEM_Term;
pTos->xDel = 0;
pTos->enc = db->enc;
pTos->z = zNew;
}
break;
}
/* Opcode: Add * * *
**
** Pop the top two elements from the stack, add them together,
** and push the result back onto the stack. If either element
** is a string then it is converted to a double using the atof()
** function before the addition.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Multiply * * *
**
** Pop the top two elements from the stack, multiply them together,
** and push the result back onto the stack. If either element
** is a string then it is converted to a double using the atof()
** function before the multiplication.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Subtract * * *
**
** Pop the top two elements from the stack, subtract the
** first (what was on top of the stack) from the second (the
** next on stack)
** and push the result back onto the stack. If either element
** is a string then it is converted to a double using the atof()
** function before the subtraction.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Divide * * *
**
** Pop the top two elements from the stack, divide the
** first (what was on top of the stack) from the second (the
** next on stack)
** and push the result back onto the stack. If either element
** is a string then it is converted to a double using the atof()
** function before the division. Division by zero returns NULL.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Remainder * * *
**
** Pop the top two elements from the stack, divide the
** first (what was on top of the stack) from the second (the
** next on stack)
** and push the remainder after division onto the stack. If either element
** is a string then it is converted to a double using the atof()
** function before the division. Division by zero returns NULL.
** If either operand is NULL, the result is NULL.
*/
case OP_Add: /* same as TK_PLUS, no-push */
case OP_Subtract: /* same as TK_MINUS, no-push */
case OP_Multiply: /* same as TK_STAR, no-push */
case OP_Divide: /* same as TK_SLASH, no-push */
case OP_Remainder: { /* same as TK_REM, no-push */
Mem *pNos = &pTos[-1];
assert( pNos>=p->aStack );
if( ((pTos->flags | pNos->flags) & MEM_Null)!=0 ){
Release(pTos);
pTos--;
Release(pTos);
pTos->flags = MEM_Null;
}else if( (pTos->flags & pNos->flags & MEM_Int)==MEM_Int ){
i64 a, b;
a = pTos->i;
b = pNos->i;
switch( pOp->opcode ){
case OP_Add: b += a; break;
case OP_Subtract: b -= a; break;
case OP_Multiply: b *= a; break;
case OP_Divide: {
if( a==0 ) goto divide_by_zero;
b /= a;
break;
}
default: {
if( a==0 ) goto divide_by_zero;
b %= a;
break;
}
}
Release(pTos);
pTos--;
Release(pTos);
pTos->i = b;
pTos->flags = MEM_Int;
}else{
double a, b;
a = sqlite3VdbeRealValue(pTos);
b = sqlite3VdbeRealValue(pNos);
switch( pOp->opcode ){
case OP_Add: b += a; break;
case OP_Subtract: b -= a; break;
case OP_Multiply: b *= a; break;
case OP_Divide: {
if( a==0.0 ) goto divide_by_zero;
b /= a;
break;
}
default: {
int ia = (int)a;
int ib = (int)b;
if( ia==0.0 ) goto divide_by_zero;
b = ib % ia;
break;
}
}
Release(pTos);
pTos--;
Release(pTos);
pTos->r = b;
pTos->flags = MEM_Real;
}
break;
divide_by_zero:
Release(pTos);
pTos--;
Release(pTos);
pTos->flags = MEM_Null;
break;
}
/* Opcode: CollSeq * * P3
**
** P3 is a pointer to a CollSeq struct. If the next call to a user function
** or aggregate calls sqlite3GetFuncCollSeq(), this collation sequence will
** be returned. This is used by the built-in min(), max() and nullif()
** functions.
**
** The interface used by the implementation of the aforementioned functions
** to retrieve the collation sequence set by this opcode is not available
** publicly, only to user functions defined in func.c.
*/
case OP_CollSeq: { /* no-push */
assert( pOp->p3type==P3_COLLSEQ );
break;
}
/* Opcode: Function P1 P2 P3
**
** Invoke a user function (P3 is a pointer to a Function structure that
** defines the function) with P2 arguments taken from the stack. Pop all
** arguments from the stack and push back the result.
**
** P1 is a 32-bit bitmask indicating whether or not each argument to the
** function was determined to be constant at compile time. If the first
** argument was constant then bit 0 of P1 is set. This is used to determine
** whether meta data associated with a user function argument using the
** sqlite3_set_auxdata() API may be safely retained until the next
** invocation of this opcode.
**
** See also: AggStep and AggFinal
*/
case OP_Function: {
int i;
Mem *pArg;
sqlite3_context ctx;
sqlite3_value **apVal;
int n = pOp->p2;
apVal = p->apArg;
assert( apVal || n==0 );
pArg = &pTos[1-n];
for(i=0; i<n; i++, pArg++){
apVal[i] = pArg;
storeTypeInfo(pArg, db->enc);
}
assert( pOp->p3type==P3_FUNCDEF || pOp->p3type==P3_VDBEFUNC );
if( pOp->p3type==P3_FUNCDEF ){
ctx.pFunc = (FuncDef*)pOp->p3;
ctx.pVdbeFunc = 0;
}else{
ctx.pVdbeFunc = (VdbeFunc*)pOp->p3;
ctx.pFunc = ctx.pVdbeFunc->pFunc;
}
ctx.s.flags = MEM_Null;
ctx.s.z = 0;
ctx.s.xDel = 0;
ctx.isError = 0;
if( ctx.pFunc->needCollSeq ){
assert( pOp>p->aOp );
assert( pOp[-1].p3type==P3_COLLSEQ );
assert( pOp[-1].opcode==OP_CollSeq );
ctx.pColl = (CollSeq *)pOp[-1].p3;
}
if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
(*ctx.pFunc->xFunc)(&ctx, n, apVal);
if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
if( sqlite3_malloc_failed ) goto no_mem;
popStack(&pTos, n);
/* If any auxilary data functions have been called by this user function,
** immediately call the destructor for any non-static values.
*/
if( ctx.pVdbeFunc ){
sqlite3VdbeDeleteAuxData(ctx.pVdbeFunc, pOp->p1);
pOp->p3 = (char *)ctx.pVdbeFunc;
pOp->p3type = P3_VDBEFUNC;
}
/* Copy the result of the function to the top of the stack */
sqlite3VdbeChangeEncoding(&ctx.s, db->enc);
pTos++;
pTos->flags = 0;
sqlite3VdbeMemMove(pTos, &ctx.s);
/* If the function returned an error, throw an exception */
if( ctx.isError ){
if( !(pTos->flags&MEM_Str) ){
sqlite3SetString(&p->zErrMsg, "user function error", (char*)0);
}else{
sqlite3SetString(&p->zErrMsg, sqlite3_value_text(pTos), (char*)0);
sqlite3VdbeChangeEncoding(pTos, db->enc);
}
rc = SQLITE_ERROR;
}
break;
}
/* Opcode: BitAnd * * *
**
** Pop the top two elements from the stack. Convert both elements
** to integers. Push back onto the stack the bit-wise AND of the
** two elements.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: BitOr * * *
**
** Pop the top two elements from the stack. Convert both elements
** to integers. Push back onto the stack the bit-wise OR of the
** two elements.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: ShiftLeft * * *
**
** Pop the top two elements from the stack. Convert both elements
** to integers. Push back onto the stack the second element shifted
** left by N bits where N is the top element on the stack.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: ShiftRight * * *
**
** Pop the top two elements from the stack. Convert both elements
** to integers. Push back onto the stack the second element shifted
** right by N bits where N is the top element on the stack.
** If either operand is NULL, the result is NULL.
*/
case OP_BitAnd: /* same as TK_BITAND, no-push */
case OP_BitOr: /* same as TK_BITOR, no-push */
case OP_ShiftLeft: /* same as TK_LSHIFT, no-push */
case OP_ShiftRight: { /* same as TK_RSHIFT, no-push */
Mem *pNos = &pTos[-1];
int a, b;
assert( pNos>=p->aStack );
if( (pTos->flags | pNos->flags) & MEM_Null ){
popStack(&pTos, 2);
pTos++;
pTos->flags = MEM_Null;
break;
}
a = sqlite3VdbeIntValue(pNos);
b = sqlite3VdbeIntValue(pTos);
switch( pOp->opcode ){
case OP_BitAnd: a &= b; break;
case OP_BitOr: a |= b; break;
case OP_ShiftLeft: a <<= b; break;
case OP_ShiftRight: a >>= b; break;
default: /* CANT HAPPEN */ break;
}
Release(pTos);
pTos--;
Release(pTos);
pTos->i = a;
pTos->flags = MEM_Int;
break;
}
/* Opcode: AddImm P1 * *
**
** Add the value P1 to whatever is on top of the stack. The result
** is always an integer.
**
** To force the top of the stack to be an integer, just add 0.
*/
case OP_AddImm: { /* no-push */
assert( pTos>=p->aStack );
Integerify(pTos);
pTos->i += pOp->p1;
break;
}
/* Opcode: ForceInt P1 P2 *
**
** Convert the top of the stack into an integer. If the current top of
** the stack is not numeric (meaning that is is a NULL or a string that
** does not look like an integer or floating point number) then pop the
** stack and jump to P2. If the top of the stack is numeric then
** convert it into the least integer that is greater than or equal to its
** current value if P1==0, or to the least integer that is strictly
** greater than its current value if P1==1.
*/
case OP_ForceInt: { /* no-push */
i64 v;
assert( pTos>=p->aStack );
applyAffinity(pTos, SQLITE_AFF_INTEGER, db->enc);
if( (pTos->flags & (MEM_Int|MEM_Real))==0 ){
Release(pTos);
pTos--;
pc = pOp->p2 - 1;
break;
}
if( pTos->flags & MEM_Int ){
v = pTos->i + (pOp->p1!=0);
}else{
Realify(pTos);
v = (int)pTos->r;
if( pTos->r>(double)v ) v++;
if( pOp->p1 && pTos->r==(double)v ) v++;
}
Release(pTos);
pTos->i = v;
pTos->flags = MEM_Int;
break;
}
/* Opcode: MustBeInt P1 P2 *
**
** Force the top of the stack to be an integer. If the top of the
** stack is not an integer and cannot be converted into an integer
** with out data loss, then jump immediately to P2, or if P2==0
** raise an SQLITE_MISMATCH exception.
**
** If the top of the stack is not an integer and P2 is not zero and
** P1 is 1, then the stack is popped. In all other cases, the depth
** of the stack is unchanged.
*/
case OP_MustBeInt: { /* no-push */
assert( pTos>=p->aStack );
applyAffinity(pTos, SQLITE_AFF_INTEGER, db->enc);
if( (pTos->flags & MEM_Int)==0 ){
if( pOp->p2==0 ){
rc = SQLITE_MISMATCH;
goto abort_due_to_error;
}else{
if( pOp->p1 ) popStack(&pTos, 1);
pc = pOp->p2 - 1;
}
}else{
Release(pTos);
pTos->flags = MEM_Int;
}
break;
}
#ifndef SQLITE_OMIT_CAST
/* Opcode: ToInt * * *
**
** Force the value on the top of the stack to be an integer. If
** The value is currently a real number, drop its fractional part.
** If the value is text or blob, try to convert it to an integer using the
** equivalent of atoi() and store 0 if no such conversion is possible.
**
** A NULL value is not changed by this routine. It remains NULL.
*/
case OP_ToInt: { /* no-push */
assert( pTos>=p->aStack );
if( pTos->flags & MEM_Null ) break;
assert( MEM_Str==(MEM_Blob>>3) );
pTos->flags |= (pTos->flags&MEM_Blob)>>3;
applyAffinity(pTos, SQLITE_AFF_INTEGER, db->enc);
sqlite3VdbeMemIntegerify(pTos);
break;
}
/* Opcode: ToNumeric * * *
**
** Force the value on the top of the stack to be numeric (either an
** integer or a floating-point number.
** If the value is text or blob, try to convert it to an using the
** equivalent of atoi() or atof() and store 0 if no such conversion
** is possible.
**
** A NULL value is not changed by this routine. It remains NULL.
*/
case OP_ToNumeric: { /* no-push */
assert( pTos>=p->aStack );
if( pTos->flags & MEM_Null ) break;
assert( MEM_Str==(MEM_Blob>>3) );
pTos->flags |= (pTos->flags&MEM_Blob)>>3;
applyAffinity(pTos, SQLITE_AFF_NUMERIC, db->enc);
if( (pTos->flags & (MEM_Int|MEM_Real))==0 ){
sqlite3VdbeMemRealify(pTos);
}else{
sqlite3VdbeMemRelease(pTos);
}
assert( (pTos->flags & MEM_Dyn)==0 );
pTos->flags &= (MEM_Int|MEM_Real);
break;
}
/* Opcode: ToText * * *
**
** Force the value on the top of the stack to be text.
** If the value is numeric, convert it to an using the
** equivalent of printf(). Blob values are unchanged and
** are afterwards simply interpreted as text.
**
** A NULL value is not changed by this routine. It remains NULL.
*/
case OP_ToText: { /* no-push */
assert( pTos>=p->aStack );
if( pTos->flags & MEM_Null ) break;
assert( MEM_Str==(MEM_Blob>>3) );
pTos->flags |= (pTos->flags&MEM_Blob)>>3;
applyAffinity(pTos, SQLITE_AFF_TEXT, db->enc);
assert( pTos->flags & MEM_Str );
pTos->flags &= ~(MEM_Int|MEM_Real|MEM_Blob);
break;
}
/* Opcode: ToBlob * * *
**
** Force the value on the top of the stack to be a BLOB.
** If the value is numeric, convert it to a string first.
** Strings are simply reinterpreted as blobs with no change
** to the underlying data.
**
** A NULL value is not changed by this routine. It remains NULL.
*/
case OP_ToBlob: { /* no-push */
assert( pTos>=p->aStack );
if( pTos->flags & MEM_Null ) break;
if( (pTos->flags & MEM_Blob)==0 ){
applyAffinity(pTos, SQLITE_AFF_TEXT, db->enc);
assert( pTos->flags & MEM_Str );
pTos->flags |= MEM_Blob;
}
pTos->flags &= ~(MEM_Int|MEM_Real|MEM_Str);
break;
}
#endif /* SQLITE_OMIT_CAST */
/* Opcode: Eq P1 P2 P3
**
** Pop the top two elements from the stack. If they are equal, then
** jump to instruction P2. Otherwise, continue to the next instruction.
**
** If the 0x100 bit of P1 is true and either operand is NULL then take the
** jump. If the 0x100 bit of P1 is clear then fall thru if either operand
** is NULL.
**
** If the 0x200 bit of P1 is set and either operand is NULL then
** both operands are converted to integers prior to comparison.
** NULL operands are converted to zero and non-NULL operands are
** converted to 1. Thus, for example, with 0x200 set, NULL==NULL is true
** whereas it would normally be NULL. Similarly, NULL==123 is false when
** 0x200 is set but is NULL when the 0x200 bit of P1 is clear.
**
** The least significant byte of P1 (mask 0xff) must be an affinity character -
** 'n', 't', 'i' or 'o' - or 0x00. An attempt is made to coerce both values
** according to the affinity before the comparison is made. If the byte is
** 0x00, then numeric affinity is used.
**
** Once any conversions have taken place, and neither value is NULL,
** the values are compared. If both values are blobs, or both are text,
** then memcmp() is used to determine the results of the comparison. If
** both values are numeric, then a numeric comparison is used. If the
** two values are of different types, then they are inequal.
**
** If P2 is zero, do not jump. Instead, push an integer 1 onto the
** stack if the jump would have been taken, or a 0 if not. Push a
** NULL if either operand was NULL.
**
** If P3 is not NULL it is a pointer to a collating sequence (a CollSeq
** structure) that defines how to compare text.
*/
/* Opcode: Ne P1 P2 P3
**
** This works just like the Eq opcode except that the jump is taken if
** the operands from the stack are not equal. See the Eq opcode for
** additional information.
*/
/* Opcode: Lt P1 P2 P3
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is less than the top of the stack.
** See the Eq opcode for additional information.
*/
/* Opcode: Le P1 P2 P3
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is less than or equal to the
** top of the stack. See the Eq opcode for additional information.
*/
/* Opcode: Gt P1 P2 P3
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is greater than the top of the stack.
** See the Eq opcode for additional information.
*/
/* Opcode: Ge P1 P2 P3
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is greater than or equal to the
** top of the stack. See the Eq opcode for additional information.
*/
case OP_Eq: /* same as TK_EQ, no-push */
case OP_Ne: /* same as TK_NE, no-push */
case OP_Lt: /* same as TK_LT, no-push */
case OP_Le: /* same as TK_LE, no-push */
case OP_Gt: /* same as TK_GT, no-push */
case OP_Ge: { /* same as TK_GE, no-push */
Mem *pNos;
int flags;
int res;
char affinity;
pNos = &pTos[-1];
flags = pTos->flags|pNos->flags;
/* If either value is a NULL P2 is not zero, take the jump if the least
** significant byte of P1 is true. If P2 is zero, then push a NULL onto
** the stack.
*/
if( flags&MEM_Null ){
if( (pOp->p1 & 0x200)!=0 ){
/* The 0x200 bit of P1 means, roughly "do not treat NULL as the
** magic SQL value it normally is - treat it as if it were another
** integer".
**
** With 0x200 set, if either operand is NULL then both operands
** are converted to integers prior to being passed down into the
** normal comparison logic below. NULL operands are converted to
** zero and non-NULL operands are converted to 1. Thus, for example,
** with 0x200 set, NULL==NULL is true whereas it would normally
** be NULL. Similarly, NULL!=123 is true.
*/
sqlite3VdbeMemSetInt64(pTos, (pTos->flags & MEM_Null)==0);
sqlite3VdbeMemSetInt64(pNos, (pNos->flags & MEM_Null)==0);
}else{
/* If the 0x200 bit of P1 is clear and either operand is NULL then
** the result is always NULL. The jump is taken if the 0x100 bit
** of P1 is set.
*/
popStack(&pTos, 2);
if( pOp->p2 ){
if( pOp->p1 & 0x100 ){
pc = pOp->p2-1;
}
}else{
pTos++;
pTos->flags = MEM_Null;
}
break;
}
}
affinity = pOp->p1 & 0xFF;
if( affinity ){
applyAffinity(pNos, affinity, db->enc);
applyAffinity(pTos, affinity, db->enc);
}
assert( pOp->p3type==P3_COLLSEQ || pOp->p3==0 );
res = sqlite3MemCompare(pNos, pTos, (CollSeq*)pOp->p3);
switch( pOp->opcode ){
case OP_Eq: res = res==0; break;
case OP_Ne: res = res!=0; break;
case OP_Lt: res = res<0; break;
case OP_Le: res = res<=0; break;
case OP_Gt: res = res>0; break;
default: res = res>=0; break;
}
popStack(&pTos, 2);
if( pOp->p2 ){
if( res ){
pc = pOp->p2-1;
}
}else{
pTos++;
pTos->flags = MEM_Int;
pTos->i = res;
}
break;
}
/* Opcode: And * * *
**
** Pop two values off the stack. Take the logical AND of the
** two values and push the resulting boolean value back onto the
** stack.
*/
/* Opcode: Or * * *
**
** Pop two values off the stack. Take the logical OR of the
** two values and push the resulting boolean value back onto the
** stack.
*/
case OP_And: /* same as TK_AND, no-push */
case OP_Or: { /* same as TK_OR, no-push */
Mem *pNos = &pTos[-1];
int v1, v2; /* 0==TRUE, 1==FALSE, 2==UNKNOWN or NULL */
assert( pNos>=p->aStack );
if( pTos->flags & MEM_Null ){
v1 = 2;
}else{
Integerify(pTos);
v1 = pTos->i==0;
}
if( pNos->flags & MEM_Null ){
v2 = 2;
}else{
Integerify(pNos);
v2 = pNos->i==0;
}
if( pOp->opcode==OP_And ){
static const unsigned char and_logic[] = { 0, 1, 2, 1, 1, 1, 2, 1, 2 };
v1 = and_logic[v1*3+v2];
}else{
static const unsigned char or_logic[] = { 0, 0, 0, 0, 1, 2, 0, 2, 2 };
v1 = or_logic[v1*3+v2];
}
popStack(&pTos, 2);
pTos++;
if( v1==2 ){
pTos->flags = MEM_Null;
}else{
pTos->i = v1==0;
pTos->flags = MEM_Int;
}
break;
}
/* Opcode: Negative * * *
**
** Treat the top of the stack as a numeric quantity. Replace it
** with its additive inverse. If the top of the stack is NULL
** its value is unchanged.
*/
/* Opcode: AbsValue * * *
**
** Treat the top of the stack as a numeric quantity. Replace it
** with its absolute value. If the top of the stack is NULL
** its value is unchanged.
*/
case OP_Negative: /* same as TK_UMINUS, no-push */
case OP_AbsValue: {
assert( pTos>=p->aStack );
if( pTos->flags & MEM_Real ){
Release(pTos);
if( pOp->opcode==OP_Negative || pTos->r<0.0 ){
pTos->r = -pTos->r;
}
pTos->flags = MEM_Real;
}else if( pTos->flags & MEM_Int ){
Release(pTos);
if( pOp->opcode==OP_Negative || pTos->i<0 ){
pTos->i = -pTos->i;
}
pTos->flags = MEM_Int;
}else if( pTos->flags & MEM_Null ){
/* Do nothing */
}else{
Realify(pTos);
if( pOp->opcode==OP_Negative || pTos->r<0.0 ){
pTos->r = -pTos->r;
}
pTos->flags = MEM_Real;
}
break;
}
/* Opcode: Not * * *
**
** Interpret the top of the stack as a boolean value. Replace it
** with its complement. If the top of the stack is NULL its value
** is unchanged.
*/
case OP_Not: { /* same as TK_NOT, no-push */
assert( pTos>=p->aStack );
if( pTos->flags & MEM_Null ) break; /* Do nothing to NULLs */
Integerify(pTos);
assert( (pTos->flags & MEM_Dyn)==0 );
pTos->i = !pTos->i;
pTos->flags = MEM_Int;
break;
}
/* Opcode: BitNot * * *
**
** Interpret the top of the stack as an value. Replace it
** with its ones-complement. If the top of the stack is NULL its
** value is unchanged.
*/
case OP_BitNot: { /* same as TK_BITNOT, no-push */
assert( pTos>=p->aStack );
if( pTos->flags & MEM_Null ) break; /* Do nothing to NULLs */
Integerify(pTos);
assert( (pTos->flags & MEM_Dyn)==0 );
pTos->i = ~pTos->i;
pTos->flags = MEM_Int;
break;
}
/* Opcode: Noop * * *
**
** Do nothing. This instruction is often useful as a jump
** destination.
*/
/*
** The magic Explain opcode are only inserted when explain==2 (which
** is to say when the EXPLAIN QUERY PLAN syntax is used.)
** This opcode records information from the optimizer. It is the
** the same as a no-op. This opcodesnever appears in a real VM program.
*/
case OP_Explain:
case OP_Noop: { /* no-push */
break;
}
/* Opcode: If P1 P2 *
**
** Pop a single boolean from the stack. If the boolean popped is
** true, then jump to p2. Otherwise continue to the next instruction.
** An integer is false if zero and true otherwise. A string is
** false if it has zero length and true otherwise.
**
** If the value popped of the stack is NULL, then take the jump if P1
** is true and fall through if P1 is false.
*/
/* Opcode: IfNot P1 P2 *
**
** Pop a single boolean from the stack. If the boolean popped is
** false, then jump to p2. Otherwise continue to the next instruction.
** An integer is false if zero and true otherwise. A string is
** false if it has zero length and true otherwise.
**
** If the value popped of the stack is NULL, then take the jump if P1
** is true and fall through if P1 is false.
*/
case OP_If: /* no-push */
case OP_IfNot: { /* no-push */
int c;
assert( pTos>=p->aStack );
if( pTos->flags & MEM_Null ){
c = pOp->p1;
}else{
#ifdef SQLITE_OMIT_FLOATING_POINT
c = sqlite3VdbeIntValue(pTos);
#else
c = sqlite3VdbeRealValue(pTos)!=0.0;
#endif
if( pOp->opcode==OP_IfNot ) c = !c;
}
Release(pTos);
pTos--;
if( c ) pc = pOp->p2-1;
break;
}
/* Opcode: IsNull P1 P2 *
**
** If any of the top abs(P1) values on the stack are NULL, then jump
** to P2. Pop the stack P1 times if P1>0. If P1<0 leave the stack
** unchanged.
*/
case OP_IsNull: { /* same as TK_ISNULL, no-push */
int i, cnt;
Mem *pTerm;
cnt = pOp->p1;
if( cnt<0 ) cnt = -cnt;
pTerm = &pTos[1-cnt];
assert( pTerm>=p->aStack );
for(i=0; i<cnt; i++, pTerm++){
if( pTerm->flags & MEM_Null ){
pc = pOp->p2-1;
break;
}
}
if( pOp->p1>0 ) popStack(&pTos, cnt);
break;
}
/* Opcode: NotNull P1 P2 *
**
** Jump to P2 if the top P1 values on the stack are all not NULL. Pop the
** stack if P1 times if P1 is greater than zero. If P1 is less than
** zero then leave the stack unchanged.
*/
case OP_NotNull: { /* same as TK_NOTNULL, no-push */
int i, cnt;
cnt = pOp->p1;
if( cnt<0 ) cnt = -cnt;
assert( &pTos[1-cnt] >= p->aStack );
for(i=0; i<cnt && (pTos[1+i-cnt].flags & MEM_Null)==0; i++){}
if( i>=cnt ) pc = pOp->p2-1;
if( pOp->p1>0 ) popStack(&pTos, cnt);
break;
}
/* Opcode: SetNumColumns P1 P2 *
**
** Before the OP_Column opcode can be executed on a cursor, this
** opcode must be called to set the number of fields in the table.
**
** This opcode sets the number of columns for cursor P1 to P2.
**
** If OP_KeyAsData is to be applied to cursor P1, it must be executed
** before this op-code.
*/
case OP_SetNumColumns: { /* no-push */
Cursor *pC;
assert( (pOp->p1)<p->nCursor );
assert( p->apCsr[pOp->p1]!=0 );
pC = p->apCsr[pOp->p1];
pC->nField = pOp->p2;
break;
}
/* Opcode: Column P1 P2 P3
**
** Interpret the data that cursor P1 points to as a structure built using
** the MakeRecord instruction. (See the MakeRecord opcode for additional
** information about the format of the data.) Push onto the stack the value
** of the P2-th column contained in the data. If there are less that (P2+1)
** values in the record, push a NULL onto the stack.
**
** If the KeyAsData opcode has previously executed on this cursor, then the
** field might be extracted from the key rather than the data.
**
** If P1 is negative, then the record is stored on the stack rather than in
** a table. For P1==-1, the top of the stack is used. For P1==-2, the
** next on the stack is used. And so forth. The value pushed is always
** just a pointer into the record which is stored further down on the
** stack. The column value is not copied. The number of columns in the
** record is stored on the stack just above the record itself.
**
** If the column contains fewer than P2 fields, then push a NULL. Or
** if P3 is of type P3_MEM, then push the P3 value. The P3 value will
** be default value for a column that has been added using the ALTER TABLE
** ADD COLUMN command. If P3 is an ordinary string, just push a NULL.
** When P3 is a string it is really just a comment describing the value
** to be pushed, not a default value.
*/
case OP_Column: {
u32 payloadSize; /* Number of bytes in the record */
int p1 = pOp->p1; /* P1 value of the opcode */
int p2 = pOp->p2; /* column number to retrieve */
Cursor *pC = 0; /* The VDBE cursor */
char *zRec; /* Pointer to complete record-data */
BtCursor *pCrsr; /* The BTree cursor */
u32 *aType; /* aType[i] holds the numeric type of the i-th column */
u32 *aOffset; /* aOffset[i] is offset to start of data for i-th column */
u32 nField; /* number of fields in the record */
u32 szHdr; /* Number of bytes in the record header */
int len; /* The length of the serialized data for the column */
int offset = 0; /* Offset into the data */
int idx; /* Index into the header */
int i; /* Loop counter */
char *zData; /* Part of the record being decoded */
Mem sMem; /* For storing the record being decoded */
sMem.flags = 0;
assert( p1<p->nCursor );
pTos++;
pTos->flags = MEM_Null;
/* This block sets the variable payloadSize to be the total number of
** bytes in the record.
**
** zRec is set to be the complete text of the record if it is available.
** The complete record text is always available for pseudo-tables and
** when we are decoded a record from the stack. If the record is stored
** in a cursor, the complete record text might be available in the
** pC->aRow cache. Or it might not be. If the data is unavailable,
** zRec is set to NULL.
**
** We also compute the number of columns in the record. For cursors,
** the number of columns is stored in the Cursor.nField element. For
** records on the stack, the next entry down on the stack is an integer
** which is the number of records.
*/
assert( p1<0 || p->apCsr[p1]!=0 );
if( p1<0 ){
/* Take the record off of the stack */
Mem *pRec = &pTos[p1];
Mem *pCnt = &pRec[-1];
assert( pRec>=p->aStack );
assert( pRec->flags & MEM_Blob );
payloadSize = pRec->n;
zRec = pRec->z;
assert( pCnt>=p->aStack );
assert( pCnt->flags & MEM_Int );
nField = pCnt->i;
pCrsr = 0;
}else if( (pC = p->apCsr[p1])->pCursor!=0 ){
/* The record is stored in a B-Tree */
rc = sqlite3VdbeCursorMoveto(pC);
if( rc ) goto abort_due_to_error;
zRec = 0;
pCrsr = pC->pCursor;
if( pC->nullRow ){
payloadSize = 0;
}else if( pC->cacheValid ){
payloadSize = pC->payloadSize;
zRec = pC->aRow;
}else if( pC->isIndex ){
i64 payloadSize64;
sqlite3BtreeKeySize(pCrsr, &payloadSize64);
payloadSize = payloadSize64;
}else{
sqlite3BtreeDataSize(pCrsr, &payloadSize);
}
nField = pC->nField;
#ifndef SQLITE_OMIT_TRIGGER
}else if( pC->pseudoTable ){
/* The record is the sole entry of a pseudo-table */
payloadSize = pC->nData;
zRec = pC->pData;
pC->cacheValid = 0;
assert( payloadSize==0 || zRec!=0 );
nField = pC->nField;
pCrsr = 0;
#endif
}else{
zRec = 0;
payloadSize = 0;
pCrsr = 0;
nField = 0;
}
/* If payloadSize is 0, then just push a NULL onto the stack. */
if( payloadSize==0 ){
pTos->flags = MEM_Null;
break;
}
assert( p2<nField );
/* Read and parse the table header. Store the results of the parse
** into the record header cache fields of the cursor.
*/
if( pC && pC->cacheValid ){
aType = pC->aType;
aOffset = pC->aOffset;
}else{
int avail; /* Number of bytes of available data */
if( pC && pC->aType ){
aType = pC->aType;
}else{
aType = sqliteMallocRaw( 2*nField*sizeof(aType) );
}
aOffset = &aType[nField];
if( aType==0 ){
goto no_mem;
}
/* Figure out how many bytes are in the header */
if( zRec ){
zData = zRec;
}else{
if( pC->isIndex ){
zData = (char*)sqlite3BtreeKeyFetch(pCrsr, &avail);
}else{
zData = (char*)sqlite3BtreeDataFetch(pCrsr, &avail);
}
/* If KeyFetch()/DataFetch() managed to get the entire payload,
** save the payload in the pC->aRow cache. That will save us from
** having to make additional calls to fetch the content portion of
** the record.
*/
if( avail>=payloadSize ){
zRec = pC->aRow = zData;
}else{
pC->aRow = 0;
}
}
idx = sqlite3GetVarint32(zData, &szHdr);
/* The KeyFetch() or DataFetch() above are fast and will get the entire
** record header in most cases. But they will fail to get the complete
** record header if the record header does not fit on a single page
** in the B-Tree. When that happens, use sqlite3VdbeMemFromBtree() to
** acquire the complete header text.
*/
if( !zRec && avail<szHdr ){
rc = sqlite3VdbeMemFromBtree(pCrsr, 0, szHdr, pC->isIndex, &sMem);
if( rc!=SQLITE_OK ){
goto op_column_out;
}
zData = sMem.z;
}
/* Scan the header and use it to fill in the aType[] and aOffset[]
** arrays. aType[i] will contain the type integer for the i-th
** column and aOffset[i] will contain the offset from the beginning
** of the record to the start of the data for the i-th column
*/
offset = szHdr;
assert( offset>0 );
i = 0;
while( idx<szHdr && i<nField && offset<=payloadSize ){
aOffset[i] = offset;
idx += sqlite3GetVarint32(&zData[idx], &aType[i]);
offset += sqlite3VdbeSerialTypeLen(aType[i]);
i++;
}
Release(&sMem);
sMem.flags = MEM_Null;
/* If i is less that nField, then there are less fields in this
** record than SetNumColumns indicated there are columns in the
** table. Set the offset for any extra columns not present in
** the record to 0. This tells code below to push a NULL onto the
** stack instead of deserializing a value from the record.
*/
while( i<nField ){
aOffset[i++] = 0;
}
/* The header should end at the start of data and the data should
** end at last byte of the record. If this is not the case then
** we are dealing with a malformed record.
*/
if( idx!=szHdr || offset!=payloadSize ){
rc = SQLITE_CORRUPT_BKPT;
goto op_column_out;
}
/* Remember all aType and aColumn information if we have a cursor
** to remember it in. */
if( pC ){
pC->payloadSize = payloadSize;
pC->aType = aType;
pC->aOffset = aOffset;
pC->cacheValid = 1;
}
}
/* Get the column information. If aOffset[p2] is non-zero, then
** deserialize the value from the record. If aOffset[p2] is zero,
** then there are not enough fields in the record to satisfy the
** request. In this case, set the value NULL or to P3 if P3 is
** a pointer to a Mem object.
*/
if( aOffset[p2] ){
assert( rc==SQLITE_OK );
if( zRec ){
zData = &zRec[aOffset[p2]];
}else{
len = sqlite3VdbeSerialTypeLen(aType[p2]);
rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, pC->isIndex,&sMem);
if( rc!=SQLITE_OK ){
goto op_column_out;
}
zData = sMem.z;
}
sqlite3VdbeSerialGet(zData, aType[p2], pTos);
pTos->enc = db->enc;
}else{
if( pOp->p3type==P3_MEM ){
sqlite3VdbeMemShallowCopy(pTos, (Mem *)(pOp->p3), MEM_Static);
}else{
pTos->flags = MEM_Null;
}
}
/* If we dynamically allocated space to hold the data (in the
** sqlite3VdbeMemFromBtree() call above) then transfer control of that
** dynamically allocated space over to the pTos structure rather.
** This prevents a memory copy.
*/
if( (sMem.flags & MEM_Dyn)!=0 ){
assert( pTos->flags & MEM_Ephem );
assert( pTos->flags & (MEM_Str|MEM_Blob) );
assert( pTos->z==sMem.z );
assert( sMem.flags & MEM_Term );
pTos->flags &= ~MEM_Ephem;
pTos->flags |= MEM_Dyn|MEM_Term;
}
/* pTos->z might be pointing to sMem.zShort[]. Fix that so that we
** can abandon sMem */
rc = sqlite3VdbeMemMakeWriteable(pTos);
op_column_out:
/* Release the aType[] memory if we are not dealing with cursor */
if( !pC || !pC->aType ){
sqliteFree(aType);
}
break;
}
/* Opcode: MakeRecord P1 P2 P3
**
** Convert the top abs(P1) entries of the stack into a single entry
** suitable for use as a data record in a database table or as a key
** in an index. The details of the format are irrelavant as long as
** the OP_Column opcode can decode the record later and as long as the
** sqlite3VdbeRecordCompare function will correctly compare two encoded
** records. Refer to source code comments for the details of the record
** format.
**
** The original stack entries are popped from the stack if P1>0 but
** remain on the stack if P1<0.
**
** If P2 is not zero and one or more of the entries are NULL, then jump
** to the address given by P2. This feature can be used to skip a
** uniqueness test on indices.
**
** P3 may be a string that is P1 characters long. The nth character of the
** string indicates the column affinity that should be used for the nth
** field of the index key (i.e. the first character of P3 corresponds to the
** lowest element on the stack).
**
** The mapping from character to affinity is as follows:
** 'n' = NUMERIC.
** 'i' = INTEGER.
** 't' = TEXT.
** 'o' = NONE.
**
** If P3 is NULL then all index fields have the affinity NONE.
**
** See also OP_MakeIdxRec
*/
/* Opcode: MakeRecordI P1 P2 P3
**
** This opcode works just OP_MakeRecord except that it reads an extra
** integer from the stack (thus reading a total of abs(P1+1) entries)
** and appends that extra integer to the end of the record as a varint.
** This results in an index key.
*/
case OP_MakeIdxRec:
case OP_MakeRecord: {
/* Assuming the record contains N fields, the record format looks
** like this:
**
** ------------------------------------------------------------------------
** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 |
** ------------------------------------------------------------------------
**
** Data(0) is taken from the lowest element of the stack and data(N-1) is
** the top of the stack.
**
** Each type field is a varint representing the serial type of the
** corresponding data element (see sqlite3VdbeSerialType()). The
** hdr-size field is also a varint which is the offset from the beginning
** of the record to data0.
*/
unsigned char *zNewRecord;
unsigned char *zCsr;
Mem *pRec;
Mem *pRowid = 0;
int nData = 0; /* Number of bytes of data space */
int nHdr = 0; /* Number of bytes of header space */
int nByte = 0; /* Space required for this record */
int nVarint; /* Number of bytes in a varint */
u32 serial_type; /* Type field */
int containsNull = 0; /* True if any of the data fields are NULL */
char zTemp[NBFS]; /* Space to hold small records */
Mem *pData0;
int leaveOnStack; /* If true, leave the entries on the stack */
int nField; /* Number of fields in the record */
int jumpIfNull; /* Jump here if non-zero and any entries are NULL. */
int addRowid; /* True to append a rowid column at the end */
char *zAffinity; /* The affinity string for the record */
leaveOnStack = ((pOp->p1<0)?1:0);
nField = pOp->p1 * (leaveOnStack?-1:1);
jumpIfNull = pOp->p2;
addRowid = pOp->opcode==OP_MakeIdxRec;
zAffinity = pOp->p3;
pData0 = &pTos[1-nField];
assert( pData0>=p->aStack );
containsNull = 0;
/* Loop through the elements that will make up the record to figure
** out how much space is required for the new record.
*/
for(pRec=pData0; pRec<=pTos; pRec++){
if( zAffinity ){
applyAffinity(pRec, zAffinity[pRec-pData0], db->enc);
}
if( pRec->flags&MEM_Null ){
containsNull = 1;
}
serial_type = sqlite3VdbeSerialType(pRec);
nData += sqlite3VdbeSerialTypeLen(serial_type);
nHdr += sqlite3VarintLen(serial_type);
}
/* If we have to append a varint rowid to this record, set 'rowid'
** to the value of the rowid and increase nByte by the amount of space
** required to store it and the 0x00 seperator byte.
*/
if( addRowid ){
pRowid = &pTos[0-nField];
assert( pRowid>=p->aStack );
Integerify(pRowid);
serial_type = sqlite3VdbeSerialType(pRowid);
nData += sqlite3VdbeSerialTypeLen(serial_type);
nHdr += sqlite3VarintLen(serial_type);
}
/* Add the initial header varint and total the size */
nHdr += nVarint = sqlite3VarintLen(nHdr);
if( nVarint<sqlite3VarintLen(nHdr) ){
nHdr++;
}
nByte = nHdr+nData;
/* Allocate space for the new record. */
if( nByte>sizeof(zTemp) ){
zNewRecord = sqliteMallocRaw(nByte);
if( !zNewRecord ){
goto no_mem;
}
}else{
zNewRecord = zTemp;
}
/* Write the record */
zCsr = zNewRecord;
zCsr += sqlite3PutVarint(zCsr, nHdr);
for(pRec=pData0; pRec<=pTos; pRec++){
serial_type = sqlite3VdbeSerialType(pRec);
zCsr += sqlite3PutVarint(zCsr, serial_type); /* serial type */
}
if( addRowid ){
zCsr += sqlite3PutVarint(zCsr, sqlite3VdbeSerialType(pRowid));
}
for(pRec=pData0; pRec<=pTos; pRec++){
zCsr += sqlite3VdbeSerialPut(zCsr, pRec); /* serial data */
}
if( addRowid ){
zCsr += sqlite3VdbeSerialPut(zCsr, pRowid);
}
assert( zCsr==(zNewRecord+nByte) );
/* Pop entries off the stack if required. Push the new record on. */
if( !leaveOnStack ){
popStack(&pTos, nField+addRowid);
}
pTos++;
pTos->n = nByte;
if( nByte<=sizeof(zTemp) ){
assert( zNewRecord==(unsigned char *)zTemp );
pTos->z = pTos->zShort;
memcpy(pTos->zShort, zTemp, nByte);
pTos->flags = MEM_Blob | MEM_Short;
}else{
assert( zNewRecord!=(unsigned char *)zTemp );
pTos->z = zNewRecord;
pTos->flags = MEM_Blob | MEM_Dyn;
pTos->xDel = 0;
}
pTos->enc = SQLITE_UTF8; /* In case the blob is ever converted to text */
/* If a NULL was encountered and jumpIfNull is non-zero, take the jump. */
if( jumpIfNull && containsNull ){
pc = jumpIfNull - 1;
}
break;
}
/* Opcode: Statement P1 * *
**
** Begin an individual statement transaction which is part of a larger
** BEGIN..COMMIT transaction. This is needed so that the statement
** can be rolled back after an error without having to roll back the
** entire transaction. The statement transaction will automatically
** commit when the VDBE halts.
**
** The statement is begun on the database file with index P1. The main
** database file has an index of 0 and the file used for temporary tables
** has an index of 1.
*/
case OP_Statement: { /* no-push */
int i = pOp->p1;
Btree *pBt;
if( i>=0 && i<db->nDb && (pBt = db->aDb[i].pBt) && !(db->autoCommit) ){
assert( sqlite3BtreeIsInTrans(pBt) );
if( !sqlite3BtreeIsInStmt(pBt) ){
rc = sqlite3BtreeBeginStmt(pBt);
}
}
break;
}
/* Opcode: AutoCommit P1 P2 *
**
** Set the database auto-commit flag to P1 (1 or 0). If P2 is true, roll
** back any currently active btree transactions. If there are any active
** VMs (apart from this one), then the COMMIT or ROLLBACK statement fails.
**
** This instruction causes the VM to halt.
*/
case OP_AutoCommit: { /* no-push */
u8 i = pOp->p1;
u8 rollback = pOp->p2;
assert( i==1 || i==0 );
assert( i==1 || rollback==0 );
assert( db->activeVdbeCnt>0 ); /* At least this one VM is active */
if( db->activeVdbeCnt>1 && i && !db->autoCommit ){
/* If this instruction implements a COMMIT or ROLLBACK, other VMs are
** still running, and a transaction is active, return an error indicating
** that the other VMs must complete first.
*/
sqlite3SetString(&p->zErrMsg, "cannot ", rollback?"rollback":"commit",
" transaction - SQL statements in progress", 0);
rc = SQLITE_ERROR;
}else if( i!=db->autoCommit ){
db->autoCommit = i;
if( pOp->p2 ){
assert( i==1 );
sqlite3RollbackAll(db);
}else if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
p->pTos = pTos;
p->pc = pc;
db->autoCommit = 1-i;
p->rc = SQLITE_BUSY;
return SQLITE_BUSY;
}
return SQLITE_DONE;
}else{
sqlite3SetString(&p->zErrMsg,
(!i)?"cannot start a transaction within a transaction":(
(rollback)?"cannot rollback - no transaction is active":
"cannot commit - no transaction is active"), 0);
rc = SQLITE_ERROR;
}
break;
}
/* Opcode: Transaction P1 P2 *
**
** Begin a transaction. The transaction ends when a Commit or Rollback
** opcode is encountered. Depending on the ON CONFLICT setting, the
** transaction might also be rolled back if an error is encountered.
**
** P1 is the index of the database file on which the transaction is
** started. Index 0 is the main database file and index 1 is the
** file used for temporary tables.
**
** If P2 is non-zero, then a write-transaction is started. A RESERVED lock is
** obtained on the database file when a write-transaction is started. No
** other process can start another write transaction while this transaction is
** underway. Starting a write transaction also creates a rollback journal. A
** write transaction must be started before any changes can be made to the
** database. If P2 is 2 or greater then an EXCLUSIVE lock is also obtained
** on the file.
**
** If P2 is zero, then a read-lock is obtained on the database file.
*/
case OP_Transaction: { /* no-push */
int i = pOp->p1;
Btree *pBt;
assert( i>=0 && i<db->nDb );
pBt = db->aDb[i].pBt;
if( pBt ){
rc = sqlite3BtreeBeginTrans(pBt, pOp->p2);
if( rc==SQLITE_BUSY ){
p->pc = pc;
p->rc = SQLITE_BUSY;
p->pTos = pTos;
return SQLITE_BUSY;
}
if( rc!=SQLITE_OK && rc!=SQLITE_READONLY /* && rc!=SQLITE_BUSY */ ){
goto abort_due_to_error;
}
}
break;
}
/* Opcode: ReadCookie P1 P2 *
**
** Read cookie number P2 from database P1 and push it onto the stack.
** P2==0 is the schema version. P2==1 is the database format.
** P2==2 is the recommended pager cache size, and so forth. P1==0 is
** the main database file and P1==1 is the database file used to store
** temporary tables.
**
** There must be a read-lock on the database (either a transaction
** must be started or there must be an open cursor) before
** executing this instruction.
*/
case OP_ReadCookie: {
int iMeta;
assert( pOp->p2<SQLITE_N_BTREE_META );
assert( pOp->p1>=0 && pOp->p1<db->nDb );
assert( db->aDb[pOp->p1].pBt!=0 );
/* The indexing of meta values at the schema layer is off by one from
** the indexing in the btree layer. The btree considers meta[0] to
** be the number of free pages in the database (a read-only value)
** and meta[1] to be the schema cookie. The schema layer considers
** meta[1] to be the schema cookie. So we have to shift the index
** by one in the following statement.
*/
rc = sqlite3BtreeGetMeta(db->aDb[pOp->p1].pBt, 1 + pOp->p2, (u32 *)&iMeta);
pTos++;
pTos->i = iMeta;
pTos->flags = MEM_Int;
break;
}
/* Opcode: SetCookie P1 P2 *
**
** Write the top of the stack into cookie number P2 of database P1.
** P2==0 is the schema version. P2==1 is the database format.
** P2==2 is the recommended pager cache size, and so forth. P1==0 is
** the main database file and P1==1 is the database file used to store
** temporary tables.
**
** A transaction must be started before executing this opcode.
*/
case OP_SetCookie: { /* no-push */
Db *pDb;
assert( pOp->p2<SQLITE_N_BTREE_META );
assert( pOp->p1>=0 && pOp->p1<db->nDb );
pDb = &db->aDb[pOp->p1];
assert( pDb->pBt!=0 );
assert( pTos>=p->aStack );
Integerify(pTos);
/* See note about index shifting on OP_ReadCookie */
rc = sqlite3BtreeUpdateMeta(pDb->pBt, 1+pOp->p2, (int)pTos->i);
if( pOp->p2==0 ){
/* When the schema cookie changes, record the new cookie internally */
pDb->schema_cookie = pTos->i;
db->flags |= SQLITE_InternChanges;
}
assert( (pTos->flags & MEM_Dyn)==0 );
pTos--;
break;
}
/* Opcode: VerifyCookie P1 P2 *
**
** Check the value of global database parameter number 0 (the
** schema version) and make sure it is equal to P2.
** P1 is the database number which is 0 for the main database file
** and 1 for the file holding temporary tables and some higher number
** for auxiliary databases.
**
** The cookie changes its value whenever the database schema changes.
** This operation is used to detect when that the cookie has changed
** and that the current process needs to reread the schema.
**
** Either a transaction needs to have been started or an OP_Open needs
** to be executed (to establish a read lock) before this opcode is
** invoked.
*/
case OP_VerifyCookie: { /* no-push */
int iMeta;
Btree *pBt;
assert( pOp->p1>=0 && pOp->p1<db->nDb );
pBt = db->aDb[pOp->p1].pBt;
if( pBt ){
rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&iMeta);
}else{
rc = SQLITE_OK;
iMeta = 0;
}
if( rc==SQLITE_OK && iMeta!=pOp->p2 ){
sqlite3SetString(&p->zErrMsg, "database schema has changed", (char*)0);
rc = SQLITE_SCHEMA;
}
break;
}
/* Opcode: OpenRead P1 P2 P3
**
** Open a read-only cursor for the database table whose root page is
** P2 in a database file. The database file is determined by an
** integer from the top of the stack. 0 means the main database and
** 1 means the database used for temporary tables. Give the new
** cursor an identifier of P1. The P1 values need not be contiguous
** but all P1 values should be small integers. It is an error for
** P1 to be negative.
**
** If P2==0 then take the root page number from the next of the stack.
**
** There will be a read lock on the database whenever there is an
** open cursor. If the database was unlocked prior to this instruction
** then a read lock is acquired as part of this instruction. A read
** lock allows other processes to read the database but prohibits
** any other process from modifying the database. The read lock is
** released when all cursors are closed. If this instruction attempts
** to get a read lock but fails, the script terminates with an
** SQLITE_BUSY error code.
**
** The P3 value is a pointer to a KeyInfo structure that defines the
** content and collating sequence of indices. P3 is NULL for cursors
** that are not pointing to indices.
**
** See also OpenWrite.
*/
/* Opcode: OpenWrite P1 P2 P3
**
** Open a read/write cursor named P1 on the table or index whose root
** page is P2. If P2==0 then take the root page number from the stack.
**
** The P3 value is a pointer to a KeyInfo structure that defines the
** content and collating sequence of indices. P3 is NULL for cursors
** that are not pointing to indices.
**
** This instruction works just like OpenRead except that it opens the cursor
** in read/write mode. For a given table, there can be one or more read-only
** cursors or a single read/write cursor but not both.
**
** See also OpenRead.
*/
case OP_OpenRead: /* no-push */
case OP_OpenWrite: { /* no-push */
int i = pOp->p1;
int p2 = pOp->p2;
int wrFlag;
Btree *pX;
int iDb;
Cursor *pCur;
assert( pTos>=p->aStack );
Integerify(pTos);
iDb = pTos->i;
assert( (pTos->flags & MEM_Dyn)==0 );
pTos--;
assert( iDb>=0 && iDb<db->nDb );
pX = db->aDb[iDb].pBt;
assert( pX!=0 );
wrFlag = pOp->opcode==OP_OpenWrite;
if( p2<=0 ){
assert( pTos>=p->aStack );
Integerify(pTos);
p2 = pTos->i;
assert( (pTos->flags & MEM_Dyn)==0 );
pTos--;
assert( p2>=2 );
}
assert( i>=0 );
pCur = allocateCursor(p, i);
if( pCur==0 ) goto no_mem;
pCur->nullRow = 1;
if( pX==0 ) break;
/* We always provide a key comparison function. If the table being
** opened is of type INTKEY, the comparision function will be ignored. */
rc = sqlite3BtreeCursor(pX, p2, wrFlag,
sqlite3VdbeRecordCompare, pOp->p3,
&pCur->pCursor);
if( pOp->p3type==P3_KEYINFO ){
pCur->pKeyInfo = (KeyInfo*)pOp->p3;
pCur->pIncrKey = &pCur->pKeyInfo->incrKey;
pCur->pKeyInfo->enc = p->db->enc;
}else{
pCur->pKeyInfo = 0;
pCur->pIncrKey = &pCur->bogusIncrKey;
}
switch( rc ){
case SQLITE_BUSY: {
p->pc = pc;
p->rc = SQLITE_BUSY;
p->pTos = &pTos[1 + (pOp->p2<=0)]; /* Operands must remain on stack */
return SQLITE_BUSY;
}
case SQLITE_OK: {
int flags = sqlite3BtreeFlags(pCur->pCursor);
/* Sanity checking. Only the lower four bits of the flags byte should
** be used. Bit 3 (mask 0x08) is unpreditable. The lower 3 bits
** (mask 0x07) should be either 5 (intkey+leafdata for tables) or
** 2 (zerodata for indices). If these conditions are not met it can
** only mean that we are dealing with a corrupt database file
*/
if( (flags & 0xf0)!=0 || ((flags & 0x07)!=5 && (flags & 0x07)!=2) ){
rc = SQLITE_CORRUPT_BKPT;
goto abort_due_to_error;
}
pCur->isTable = (flags & BTREE_INTKEY)!=0;
pCur->isIndex = (flags & BTREE_ZERODATA)!=0;
/* If P3==0 it means we are expected to open a table. If P3!=0 then
** we expect to be opening an index. If this is not what happened,
** then the database is corrupt
*/
if( (pCur->isTable && pOp->p3type==P3_KEYINFO)
|| (pCur->isIndex && pOp->p3type!=P3_KEYINFO) ){
rc = SQLITE_CORRUPT_BKPT;
goto abort_due_to_error;
}
break;
}
case SQLITE_EMPTY: {
pCur->isTable = pOp->p3type!=P3_KEYINFO;
pCur->isIndex = !pCur->isTable;
rc = SQLITE_OK;
break;
}
default: {
goto abort_due_to_error;
}
}
break;
}
/* Opcode: OpenVirtual P1 P2 P3
**
** Open a new cursor P1 to a transient or virtual table.
** The cursor is always opened read/write even if
** the main database is read-only. The transient or virtual
** table is deleted automatically when the cursor is closed.
**
** P2 is the number of columns in the virtual table.
** The cursor points to a BTree table if P3==0 and to a BTree index
** if P3 is not 0. If P3 is not NULL, it points to a KeyInfo structure
** that defines the format of keys in the index.
*/
case OP_OpenVirtual: { /* no-push */
int i = pOp->p1;
Cursor *pCx;
assert( i>=0 );
pCx = allocateCursor(p, i);
if( pCx==0 ) goto no_mem;
pCx->nullRow = 1;
rc = sqlite3BtreeFactory(db, 0, 1, TEMP_PAGES, &pCx->pBt);
if( rc==SQLITE_OK ){
rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);
}
if( rc==SQLITE_OK ){
/* If a transient index is required, create it by calling
** sqlite3BtreeCreateTable() with the BTREE_ZERODATA flag before
** opening it. If a transient table is required, just use the
** automatically created table with root-page 1 (an INTKEY table).
*/
if( pOp->p3 ){
int pgno;
assert( pOp->p3type==P3_KEYINFO );
rc = sqlite3BtreeCreateTable(pCx->pBt, &pgno, BTREE_ZERODATA);
if( rc==SQLITE_OK ){
assert( pgno==MASTER_ROOT+1 );
rc = sqlite3BtreeCursor(pCx->pBt, pgno, 1, sqlite3VdbeRecordCompare,
pOp->p3, &pCx->pCursor);
pCx->pKeyInfo = (KeyInfo*)pOp->p3;
pCx->pKeyInfo->enc = p->db->enc;
pCx->pIncrKey = &pCx->pKeyInfo->incrKey;
}
pCx->isTable = 0;
}else{
rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, 1, 0, 0, &pCx->pCursor);
pCx->isTable = 1;
pCx->pIncrKey = &pCx->bogusIncrKey;
}
}
pCx->nField = pOp->p2;
pCx->isIndex = !pCx->isTable;
break;
}
#ifndef SQLITE_OMIT_TRIGGER
/* Opcode: OpenPseudo P1 * *
**
** Open a new cursor that points to a fake table that contains a single
** row of data. Any attempt to write a second row of data causes the
** first row to be deleted. All data is deleted when the cursor is
** closed.
**
** A pseudo-table created by this opcode is useful for holding the
** NEW or OLD tables in a trigger.
*/
case OP_OpenPseudo: { /* no-push */
int i = pOp->p1;
Cursor *pCx;
assert( i>=0 );
pCx = allocateCursor(p, i);
if( pCx==0 ) goto no_mem;
pCx->nullRow = 1;
pCx->pseudoTable = 1;
pCx->pIncrKey = &pCx->bogusIncrKey;
pCx->isTable = 1;
pCx->isIndex = 0;
break;
}
#endif
/* Opcode: Close P1 * *
**
** Close a cursor previously opened as P1. If P1 is not
** currently open, this instruction is a no-op.
*/
case OP_Close: { /* no-push */
int i = pOp->p1;
if( i>=0 && i<p->nCursor ){
sqlite3VdbeFreeCursor(p->apCsr[i]);
p->apCsr[i] = 0;
}
break;
}
/* Opcode: MoveGe P1 P2 *
**
** Pop the top of the stack and use its value as a key. Reposition
** cursor P1 so that it points to the smallest entry that is greater
** than or equal to the key that was popped ffrom the stack.
** If there are no records greater than or equal to the key and P2
** is not zero, then jump to P2.
**
** See also: Found, NotFound, Distinct, MoveLt, MoveGt, MoveLe
*/
/* Opcode: MoveGt P1 P2 *
**
** Pop the top of the stack and use its value as a key. Reposition
** cursor P1 so that it points to the smallest entry that is greater
** than the key from the stack.
** If there are no records greater than the key and P2 is not zero,
** then jump to P2.
**
** See also: Found, NotFound, Distinct, MoveLt, MoveGe, MoveLe
*/
/* Opcode: MoveLt P1 P2 *
**
** Pop the top of the stack and use its value as a key. Reposition
** cursor P1 so that it points to the largest entry that is less
** than the key from the stack.
** If there are no records less than the key and P2 is not zero,
** then jump to P2.
**
** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLe
*/
/* Opcode: MoveLe P1 P2 *
**
** Pop the top of the stack and use its value as a key. Reposition
** cursor P1 so that it points to the largest entry that is less than
** or equal to the key that was popped from the stack.
** If there are no records less than or eqal to the key and P2 is not zero,
** then jump to P2.
**
** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLt
*/
case OP_MoveLt: /* no-push */
case OP_MoveLe: /* no-push */
case OP_MoveGe: /* no-push */
case OP_MoveGt: { /* no-push */
int i = pOp->p1;
Cursor *pC;
assert( pTos>=p->aStack );
assert( i>=0 && i<p->nCursor );
pC = p->apCsr[i];
assert( pC!=0 );
if( pC->pCursor!=0 ){
int res, oc;
oc = pOp->opcode;
pC->nullRow = 0;
*pC->pIncrKey = oc==OP_MoveGt || oc==OP_MoveLe;
if( pC->isTable ){
i64 iKey;
Integerify(pTos);
iKey = intToKey(pTos->i);
if( pOp->p2==0 && pOp->opcode==OP_MoveGe ){
pC->movetoTarget = iKey;
pC->deferredMoveto = 1;
assert( (pTos->flags & MEM_Dyn)==0 );
pTos--;
break;
}
rc = sqlite3BtreeMoveto(pC->pCursor, 0, (u64)iKey, &res);
if( rc!=SQLITE_OK ){
goto abort_due_to_error;
}
pC->lastRowid = pTos->i;
pC->rowidIsValid = res==0;
}else{
Stringify(pTos, db->enc);
rc = sqlite3BtreeMoveto(pC->pCursor, pTos->z, pTos->n, &res);
if( rc!=SQLITE_OK ){
goto abort_due_to_error;
}
pC->rowidIsValid = 0;
}
pC->deferredMoveto = 0;
pC->cacheValid = 0;
*pC->pIncrKey = 0;
sqlite3_search_count++;
if( oc==OP_MoveGe || oc==OP_MoveGt ){
if( res<0 ){
rc = sqlite3BtreeNext(pC->pCursor, &res);
if( rc!=SQLITE_OK ) goto abort_due_to_error;
pC->rowidIsValid = 0;
}else{
res = 0;
}
}else{
assert( oc==OP_MoveLt || oc==OP_MoveLe );
if( res>=0 ){
rc = sqlite3BtreePrevious(pC->pCursor, &res);
if( rc!=SQLITE_OK ) goto abort_due_to_error;
pC->rowidIsValid = 0;
}else{
/* res might be negative because the table is empty. Check to
** see if this is the case.
*/
res = sqlite3BtreeEof(pC->pCursor);
}
}
if( res ){
if( pOp->p2>0 ){
pc = pOp->p2 - 1;
}else{
pC->nullRow = 1;
}
}
}
Release(pTos);
pTos--;
break;
}
/* Opcode: Distinct P1 P2 *
**
** Use the top of the stack as a record created using MakeRecord. P1 is a
** cursor on a table that declared as an index. If that table contains an
** entry that matches the top of the stack fall thru. If the top of the stack
** matches no entry in P1 then jump to P2.
**
** The cursor is left pointing at the matching entry if it exists. The
** record on the top of the stack is not popped.
**
** This instruction is similar to NotFound except that this operation
** does not pop the key from the stack.
**
** The instruction is used to implement the DISTINCT operator on SELECT
** statements. The P1 table is not a true index but rather a record of
** all results that have produced so far.
**
** See also: Found, NotFound, MoveTo, IsUnique, NotExists
*/
/* Opcode: Found P1 P2 *
**
** Top of the stack holds a blob constructed by MakeRecord. P1 is an index.
** If an entry that matches the top of the stack exists in P1 then
** jump to P2. If the top of the stack does not match any entry in P1
** then fall thru. The P1 cursor is left pointing at the matching entry
** if it exists. The blob is popped off the top of the stack.
**
** This instruction is used to implement the IN operator where the
** left-hand side is a SELECT statement. P1 is not a true index but
** is instead a temporary index that holds the results of the SELECT
** statement. This instruction just checks to see if the left-hand side
** of the IN operator (stored on the top of the stack) exists in the
** result of the SELECT statement.
**
** See also: Distinct, NotFound, MoveTo, IsUnique, NotExists
*/
/* Opcode: NotFound P1 P2 *
**
** The top of the stack holds a blob constructed by MakeRecord. P1 is
** an index. If no entry exists in P1 that matches the blob then jump
** to P1. If an entry does existing, fall through. The cursor is left
** pointing to the entry that matches. The blob is popped from the stack.
**
** The difference between this operation and Distinct is that
** Distinct does not pop the key from the stack.
**
** See also: Distinct, Found, MoveTo, NotExists, IsUnique
*/
case OP_Distinct: /* no-push */
case OP_NotFound: /* no-push */
case OP_Found: { /* no-push */
int i = pOp->p1;
int alreadyExists = 0;
Cursor *pC;
assert( pTos>=p->aStack );
assert( i>=0 && i<p->nCursor );
assert( p->apCsr[i]!=0 );
if( (pC = p->apCsr[i])->pCursor!=0 ){
int res, rx;
assert( pC->isTable==0 );
Stringify(pTos, db->enc);
rx = sqlite3BtreeMoveto(pC->pCursor, pTos->z, pTos->n, &res);
alreadyExists = rx==SQLITE_OK && res==0;
pC->deferredMoveto = 0;
pC->cacheValid = 0;
}
if( pOp->opcode==OP_Found ){
if( alreadyExists ) pc = pOp->p2 - 1;
}else{
if( !alreadyExists ) pc = pOp->p2 - 1;
}
if( pOp->opcode!=OP_Distinct ){
Release(pTos);
pTos--;
}
break;
}
/* Opcode: IsUnique P1 P2 *
**
** The top of the stack is an integer record number. Call this
** record number R. The next on the stack is an index key created
** using MakeIdxKey. Call it K. This instruction pops R from the
** stack but it leaves K unchanged.
**
** P1 is an index. So it has no data and its key consists of a
** record generated by OP_MakeRecord where the last field is the
** rowid of the entry that the index refers to.
**
** This instruction asks if there is an entry in P1 where the
** fields matches K but the rowid is different from R.
** If there is no such entry, then there is an immediate
** jump to P2. If any entry does exist where the index string
** matches K but the record number is not R, then the record
** number for that entry is pushed onto the stack and control
** falls through to the next instruction.
**
** See also: Distinct, NotFound, NotExists, Found
*/
case OP_IsUnique: { /* no-push */
int i = pOp->p1;
Mem *pNos = &pTos[-1];
Cursor *pCx;
BtCursor *pCrsr;
i64 R;
/* Pop the value R off the top of the stack
*/
assert( pNos>=p->aStack );
Integerify(pTos);
R = pTos->i;
assert( (pTos->flags & MEM_Dyn)==0 );
pTos--;
assert( i>=0 && i<=p->nCursor );
pCx = p->apCsr[i];
assert( pCx!=0 );
pCrsr = pCx->pCursor;
if( pCrsr!=0 ){
int res, rc;
i64 v; /* The record number on the P1 entry that matches K */
char *zKey; /* The value of K */
int nKey; /* Number of bytes in K */
int len; /* Number of bytes in K without the rowid at the end */
int szRowid; /* Size of the rowid column at the end of zKey */
/* Make sure K is a string and make zKey point to K
*/
Stringify(pNos, db->enc);
zKey = pNos->z;
nKey = pNos->n;
szRowid = sqlite3VdbeIdxRowidLen(nKey, zKey);
len = nKey-szRowid;
/* Search for an entry in P1 where all but the last four bytes match K.
** If there is no such entry, jump immediately to P2.
*/
assert( pCx->deferredMoveto==0 );
pCx->cacheValid = 0;
rc = sqlite3BtreeMoveto(pCrsr, zKey, len, &res);
if( rc!=SQLITE_OK ) goto abort_due_to_error;
if( res<0 ){
rc = sqlite3BtreeNext(pCrsr, &res);
if( res ){
pc = pOp->p2 - 1;
break;
}
}
rc = sqlite3VdbeIdxKeyCompare(pCx, len, zKey, &res);
if( rc!=SQLITE_OK ) goto abort_due_to_error;
if( res>0 ){
pc = pOp->p2 - 1;
break;
}
/* At this point, pCrsr is pointing to an entry in P1 where all but
** the final entry (the rowid) matches K. Check to see if the
** final rowid column is different from R. If it equals R then jump
** immediately to P2.
*/
rc = sqlite3VdbeIdxRowid(pCrsr, &v);
if( rc!=SQLITE_OK ){
goto abort_due_to_error;
}
if( v==R ){
pc = pOp->p2 - 1;
break;
}
/* The final varint of the key is different from R. Push it onto
** the stack. (The record number of an entry that violates a UNIQUE
** constraint.)
*/
pTos++;
pTos->i = v;
pTos->flags = MEM_Int;
}
break;
}
/* Opcode: NotExists P1 P2 *
**
** Use the top of the stack as a integer key. If a record with that key
** does not exist in table of P1, then jump to P2. If the record
** does exist, then fall thru. The cursor is left pointing to the
** record if it exists. The integer key is popped from the stack.
**
** The difference between this operation and NotFound is that this
** operation assumes the key is an integer and that P1 is a table whereas
** NotFound assumes key is a blob constructed from MakeRecord and
** P1 is an index.
**
** See also: Distinct, Found, MoveTo, NotFound, IsUnique
*/
case OP_NotExists: { /* no-push */
int i = pOp->p1;
Cursor *pC;
BtCursor *pCrsr;
assert( pTos>=p->aStack );
assert( i>=0 && i<p->nCursor );
assert( p->apCsr[i]!=0 );
if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
int res;
u64 iKey;
assert( pTos->flags & MEM_Int );
assert( p->apCsr[i]->isTable );
iKey = intToKey(pTos->i);
rc = sqlite3BtreeMoveto(pCrsr, 0, iKey, &res);
pC->lastRowid = pTos->i;
pC->rowidIsValid = res==0;
pC->nullRow = 0;
pC->cacheValid = 0;
if( res!=0 ){
pc = pOp->p2 - 1;
pC->rowidIsValid = 0;
}
}
Release(pTos);
pTos--;
break;
}
/* Opcode: Sequence P1 * *
**
** Push an integer onto the stack which is the next available
** sequence number for cursor P1. The sequence number on the
** cursor is incremented after the push.
*/
case OP_Sequence: {
int i = pOp->p1;
assert( pTos>=p->aStack );
assert( i>=0 && i<p->nCursor );
assert( p->apCsr[i]!=0 );
pTos++;
pTos->i = p->apCsr[i]->seqCount++;
pTos->flags = MEM_Int;
break;
}
/* Opcode: NewRowid P1 P2 *
**
** Get a new integer record number (a.k.a "rowid") used as the key to a table.
** The record number is not previously used as a key in the database
** table that cursor P1 points to. The new record number is pushed
** onto the stack.
**
** If P2>0 then P2 is a memory cell that holds the largest previously
** generated record number. No new record numbers are allowed to be less
** than this value. When this value reaches its maximum, a SQLITE_FULL
** error is generated. The P2 memory cell is updated with the generated
** record number. This P2 mechanism is used to help implement the
** AUTOINCREMENT feature.
*/
case OP_NewRowid: {
int i = pOp->p1;
i64 v = 0;
Cursor *pC;
assert( i>=0 && i<p->nCursor );
assert( p->apCsr[i]!=0 );
if( (pC = p->apCsr[i])->pCursor==0 ){
/* The zero initialization above is all that is needed */
}else{
/* The next rowid or record number (different terms for the same
** thing) is obtained in a two-step algorithm.
**
** First we attempt to find the largest existing rowid and add one
** to that. But if the largest existing rowid is already the maximum
** positive integer, we have to fall through to the second
** probabilistic algorithm
**
** The second algorithm is to select a rowid at random and see if
** it already exists in the table. If it does not exist, we have
** succeeded. If the random rowid does exist, we select a new one
** and try again, up to 1000 times.
**
** For a table with less than 2 billion entries, the probability
** of not finding a unused rowid is about 1.0e-300. This is a
** non-zero probability, but it is still vanishingly small and should
** never cause a problem. You are much, much more likely to have a
** hardware failure than for this algorithm to fail.
**
** The analysis in the previous paragraph assumes that you have a good
** source of random numbers. Is a library function like lrand48()
** good enough? Maybe. Maybe not. It's hard to know whether there
** might be subtle bugs is some implementations of lrand48() that
** could cause problems. To avoid uncertainty, SQLite uses its own
** random number generator based on the RC4 algorithm.
**
** To promote locality of reference for repetitive inserts, the
** first few attempts at chosing a random rowid pick values just a little
** larger than the previous rowid. This has been shown experimentally
** to double the speed of the COPY operation.
*/
int res, rx=SQLITE_OK, cnt;
i64 x;
cnt = 0;
if( (sqlite3BtreeFlags(pC->pCursor)&(BTREE_INTKEY|BTREE_ZERODATA)) !=
BTREE_INTKEY ){
rc = SQLITE_CORRUPT_BKPT;
goto abort_due_to_error;
}
assert( (sqlite3BtreeFlags(pC->pCursor) & BTREE_INTKEY)!=0 );
assert( (sqlite3BtreeFlags(pC->pCursor) & BTREE_ZERODATA)==0 );
#ifdef SQLITE_32BIT_ROWID
# define MAX_ROWID 0x7fffffff
#else
/* Some compilers complain about constants of the form 0x7fffffffffffffff.
** Others complain about 0x7ffffffffffffffffLL. The following macro seems
** to provide the constant while making all compilers happy.
*/
# define MAX_ROWID ( (((u64)0x7fffffff)<<32) | (u64)0xffffffff )
#endif
if( !pC->useRandomRowid ){
if( pC->nextRowidValid ){
v = pC->nextRowid;
}else{
rx = sqlite3BtreeLast(pC->pCursor, &res);
if( res ){
v = 1;
}else{
sqlite3BtreeKeySize(pC->pCursor, &v);
v = keyToInt(v);
if( v==MAX_ROWID ){
pC->useRandomRowid = 1;
}else{
v++;
}
}
}
#ifndef SQLITE_OMIT_AUTOINCREMENT
if( pOp->p2 ){
Mem *pMem;
assert( pOp->p2>0 && pOp->p2<p->nMem ); /* P2 is a valid memory cell */
pMem = &p->aMem[pOp->p2];
Integerify(pMem);
assert( (pMem->flags & MEM_Int)!=0 ); /* mem(P2) holds an integer */
if( pMem->i==MAX_ROWID || pC->useRandomRowid ){
rc = SQLITE_FULL;
goto abort_due_to_error;
}
if( v<pMem->i+1 ){
v = pMem->i + 1;
}
pMem->i = v;
}
#endif
if( v<MAX_ROWID ){
pC->nextRowidValid = 1;
pC->nextRowid = v+1;
}else{
pC->nextRowidValid = 0;
}
}
if( pC->useRandomRowid ){
assert( pOp->p2==0 ); /* SQLITE_FULL must have occurred prior to this */
v = db->priorNewRowid;
cnt = 0;
do{
if( v==0 || cnt>2 ){
sqlite3Randomness(sizeof(v), &v);
if( cnt<5 ) v &= 0xffffff;
}else{
unsigned char r;
sqlite3Randomness(1, &r);
v += r + 1;
}
if( v==0 ) continue;
x = intToKey(v);
rx = sqlite3BtreeMoveto(pC->pCursor, 0, (u64)x, &res);
cnt++;
}while( cnt<1000 && rx==SQLITE_OK && res==0 );
db->priorNewRowid = v;
if( rx==SQLITE_OK && res==0 ){
rc = SQLITE_FULL;
goto abort_due_to_error;
}
}
pC->rowidIsValid = 0;
pC->deferredMoveto = 0;
pC->cacheValid = 0;
}
pTos++;
pTos->i = v;
pTos->flags = MEM_Int;
break;
}
/* Opcode: Insert P1 P2 *
**
** Write an entry into the table of cursor P1. A new entry is
** created if it doesn't already exist or the data for an existing
** entry is overwritten. The data is the value on the top of the
** stack. The key is the next value down on the stack. The key must
** be an integer. The stack is popped twice by this instruction.
**
** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
** incremented (otherwise not). If the OPFLAG_LASTROWID flag of P2 is set,
** then rowid is stored for subsequent return by the
** sqlite3_last_insert_rowid() function (otherwise it's unmodified).
**
** This instruction only works on tables. The equivalent instruction
** for indices is OP_IdxInsert.
*/
case OP_Insert: { /* no-push */
Mem *pNos = &pTos[-1];
int i = pOp->p1;
Cursor *pC;
assert( pNos>=p->aStack );
assert( i>=0 && i<p->nCursor );
assert( p->apCsr[i]!=0 );
if( ((pC = p->apCsr[i])->pCursor!=0 || pC->pseudoTable) ){
i64 iKey; /* The integer ROWID or key for the record to be inserted */
assert( pNos->flags & MEM_Int );
assert( pC->isTable );
iKey = intToKey(pNos->i);
if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
if( pOp->p2 & OPFLAG_LASTROWID ) db->lastRowid = pNos->i;
if( pC->nextRowidValid && pTos->i>=pC->nextRowid ){
pC->nextRowidValid = 0;
}
if( pTos->flags & MEM_Null ){
pTos->z = 0;
pTos->n = 0;
}else{
assert( pTos->flags & (MEM_Blob|MEM_Str) );
}
#ifndef SQLITE_OMIT_TRIGGER
if( pC->pseudoTable ){
sqliteFree(pC->pData);
pC->iKey = iKey;
pC->nData = pTos->n;
if( pTos->flags & MEM_Dyn ){
pC->pData = pTos->z;
pTos->flags = MEM_Null;
}else{
pC->pData = sqliteMallocRaw( pC->nData+2 );
if( !pC->pData ) goto no_mem;
memcpy(pC->pData, pTos->z, pC->nData);
pC->pData[pC->nData] = 0;
pC->pData[pC->nData+1] = 0;
}
pC->nullRow = 0;
}else{
#endif
rc = sqlite3BtreeInsert(pC->pCursor, 0, iKey, pTos->z, pTos->n);
#ifndef SQLITE_OMIT_TRIGGER
}
#endif
pC->rowidIsValid = 0;
pC->deferredMoveto = 0;
pC->cacheValid = 0;
}
popStack(&pTos, 2);
break;
}
/* Opcode: Delete P1 P2 *
**
** Delete the record at which the P1 cursor is currently pointing.
**
** The cursor will be left pointing at either the next or the previous
** record in the table. If it is left pointing at the next record, then
** the next Next instruction will be a no-op. Hence it is OK to delete
** a record from within an Next loop.
**
** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
** incremented (otherwise not).
**
** If P1 is a pseudo-table, then this instruction is a no-op.
*/
case OP_Delete: { /* no-push */
int i = pOp->p1;
Cursor *pC;
assert( i>=0 && i<p->nCursor );
pC = p->apCsr[i];
assert( pC!=0 );
if( pC->pCursor!=0 ){
rc = sqlite3VdbeCursorMoveto(pC);
if( rc ) goto abort_due_to_error;
rc = sqlite3BtreeDelete(pC->pCursor);
pC->nextRowidValid = 0;
pC->cacheValid = 0;
}
if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
break;
}
/* Opcode: ResetCount P1 * *
**
** This opcode resets the VMs internal change counter to 0. If P1 is true,
** then the value of the change counter is copied to the database handle
** change counter (returned by subsequent calls to sqlite3_changes())
** before it is reset. This is used by trigger programs.
*/
case OP_ResetCount: { /* no-push */
if( pOp->p1 ){
sqlite3VdbeSetChanges(db, p->nChange);
}
p->nChange = 0;
break;
}
/* Opcode: RowData P1 * *
**
** Push onto the stack the complete row data for cursor P1.
** There is no interpretation of the data. It is just copied
** onto the stack exactly as it is found in the database file.
**
** If the cursor is not pointing to a valid row, a NULL is pushed
** onto the stack.
*/
/* Opcode: RowKey P1 * *
**
** Push onto the stack the complete row key for cursor P1.
** There is no interpretation of the key. It is just copied
** onto the stack exactly as it is found in the database file.
**
** If the cursor is not pointing to a valid row, a NULL is pushed
** onto the stack.
*/
case OP_RowKey:
case OP_RowData: {
int i = pOp->p1;
Cursor *pC;
u32 n;
/* Note that RowKey and RowData are really exactly the same instruction */
pTos++;
assert( i>=0 && i<p->nCursor );
pC = p->apCsr[i];
assert( pC->isTable || pOp->opcode==OP_RowKey );
assert( pC->isIndex || pOp->opcode==OP_RowData );
assert( pC!=0 );
if( pC->nullRow ){
pTos->flags = MEM_Null;
}else if( pC->pCursor!=0 ){
BtCursor *pCrsr = pC->pCursor;
rc = sqlite3VdbeCursorMoveto(pC);
if( rc ) goto abort_due_to_error;
if( pC->nullRow ){
pTos->flags = MEM_Null;
break;
}else if( pC->isIndex ){
i64 n64;
assert( !pC->isTable );
sqlite3BtreeKeySize(pCrsr, &n64);
n = n64;
}else{
sqlite3BtreeDataSize(pCrsr, &n);
}
pTos->n = n;
if( n<=NBFS ){
pTos->flags = MEM_Blob | MEM_Short;
pTos->z = pTos->zShort;
}else{
char *z = sqliteMallocRaw( n );
if( z==0 ) goto no_mem;
pTos->flags = MEM_Blob | MEM_Dyn;
pTos->xDel = 0;
pTos->z = z;
}
if( pC->isIndex ){
sqlite3BtreeKey(pCrsr, 0, n, pTos->z);
}else{
sqlite3BtreeData(pCrsr, 0, n, pTos->z);
}
#ifndef SQLITE_OMIT_TRIGGER
}else if( pC->pseudoTable ){
pTos->n = pC->nData;
pTos->z = pC->pData;
pTos->flags = MEM_Blob|MEM_Ephem;
#endif
}else{
pTos->flags = MEM_Null;
}
pTos->enc = SQLITE_UTF8; /* In case the blob is ever cast to text */
break;
}
/* Opcode: Rowid P1 * *
**
** Push onto the stack an integer which is the key of the table entry that
** P1 is currently point to.
*/
case OP_Rowid: {
int i = pOp->p1;
Cursor *pC;
i64 v;
assert( i>=0 && i<p->nCursor );
pC = p->apCsr[i];
assert( pC!=0 );
rc = sqlite3VdbeCursorMoveto(pC);
if( rc ) goto abort_due_to_error;
pTos++;
if( pC->rowidIsValid ){
v = pC->lastRowid;
}else if( pC->pseudoTable ){
v = keyToInt(pC->iKey);
}else if( pC->nullRow || pC->pCursor==0 ){
pTos->flags = MEM_Null;
break;
}else{
assert( pC->pCursor!=0 );
sqlite3BtreeKeySize(pC->pCursor, &v);
v = keyToInt(v);
}
pTos->i = v;
pTos->flags = MEM_Int;
break;
}
/* Opcode: NullRow P1 * *
**
** Move the cursor P1 to a null row. Any OP_Column operations
** that occur while the cursor is on the null row will always push
** a NULL onto the stack.
*/
case OP_NullRow: { /* no-push */
int i = pOp->p1;
Cursor *pC;
assert( i>=0 && i<p->nCursor );
pC = p->apCsr[i];
assert( pC!=0 );
pC->nullRow = 1;
pC->rowidIsValid = 0;
break;
}
/* Opcode: Last P1 P2 *
**
** The next use of the Rowid or Column or Next instruction for P1
** will refer to the last entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
*/
case OP_Last: { /* no-push */
int i = pOp->p1;
Cursor *pC;
BtCursor *pCrsr;
assert( i>=0 && i<p->nCursor );
pC = p->apCsr[i];
assert( pC!=0 );
if( (pCrsr = pC->pCursor)!=0 ){
int res;
rc = sqlite3BtreeLast(pCrsr, &res);
pC->nullRow = res;
pC->deferredMoveto = 0;
pC->cacheValid = 0;
if( res && pOp->p2>0 ){
pc = pOp->p2 - 1;
}
}else{
pC->nullRow = 0;
}
break;
}
/* Opcode: Sort P1 P2 *
**
** This opcode does exactly the same thing as OP_Rewind except that
** it increments an undocumented global variable used for testing.
**
** Sorting is accomplished by writing records into a sorting index,
** then rewinding that index and playing it back from beginning to
** end. We use the OP_Sort opcode instead of OP_Rewind to do the
** rewinding so that the global variable will be incremented and
** regression tests can determine whether or not the optimizer is
** correctly optimizing out sorts.
*/
case OP_Sort: { /* no-push */
sqlite3_sort_count++;
sqlite3_search_count--;
/* Fall through into OP_Rewind */
}
/* Opcode: Rewind P1 P2 *
**
** The next use of the Rowid or Column or Next instruction for P1
** will refer to the first entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
*/
case OP_Rewind: { /* no-push */
int i = pOp->p1;
Cursor *pC;
BtCursor *pCrsr;
int res;
assert( i>=0 && i<p->nCursor );
pC = p->apCsr[i];
assert( pC!=0 );
if( (pCrsr = pC->pCursor)!=0 ){
rc = sqlite3BtreeFirst(pCrsr, &res);
pC->atFirst = res==0;
pC->deferredMoveto = 0;
pC->cacheValid = 0;
}else{
res = 1;
}
pC->nullRow = res;
if( res && pOp->p2>0 ){
pc = pOp->p2 - 1;
}
break;
}
/* Opcode: Next P1 P2 *
**
** Advance cursor P1 so that it points to the next key/data pair in its
** table or index. If there are no more key/value pairs then fall through
** to the following instruction. But if the cursor advance was successful,
** jump immediately to P2.
**
** See also: Prev
*/
/* Opcode: Prev P1 P2 *
**
** Back up cursor P1 so that it points to the previous key/data pair in its
** table or index. If there is no previous key/value pairs then fall through
** to the following instruction. But if the cursor backup was successful,
** jump immediately to P2.
*/
case OP_Prev: /* no-push */
case OP_Next: { /* no-push */
Cursor *pC;
BtCursor *pCrsr;
CHECK_FOR_INTERRUPT;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
if( (pCrsr = pC->pCursor)!=0 ){
int res;
if( pC->nullRow ){
res = 1;
}else{
assert( pC->deferredMoveto==0 );
rc = pOp->opcode==OP_Next ? sqlite3BtreeNext(pCrsr, &res) :
sqlite3BtreePrevious(pCrsr, &res);
pC->nullRow = res;
pC->cacheValid = 0;
}
if( res==0 ){
pc = pOp->p2 - 1;
sqlite3_search_count++;
}
}else{
pC->nullRow = 1;
}
pC->rowidIsValid = 0;
break;
}
/* Opcode: IdxInsert P1 * *
**
** The top of the stack holds a SQL index key made using the
** MakeIdxKey instruction. This opcode writes that key into the
** index P1. Data for the entry is nil.
**
** This instruction only works for indices. The equivalent instruction
** for tables is OP_Insert.
*/
case OP_IdxInsert: { /* no-push */
int i = pOp->p1;
Cursor *pC;
BtCursor *pCrsr;
assert( pTos>=p->aStack );
assert( i>=0 && i<p->nCursor );
assert( p->apCsr[i]!=0 );
assert( pTos->flags & MEM_Blob );
assert( pOp->p2==0 );
if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
int nKey = pTos->n;
const char *zKey = pTos->z;
assert( pC->isTable==0 );
rc = sqlite3BtreeInsert(pCrsr, zKey, nKey, "", 0);
assert( pC->deferredMoveto==0 );
pC->cacheValid = 0;
}
Release(pTos);
pTos--;
break;
}
/* Opcode: IdxDelete P1 * *
**
** The top of the stack is an index key built using the MakeIdxKey opcode.
** This opcode removes that entry from the index.
*/
case OP_IdxDelete: { /* no-push */
int i = pOp->p1;
Cursor *pC;
BtCursor *pCrsr;
assert( pTos>=p->aStack );
assert( pTos->flags & MEM_Blob );
assert( i>=0 && i<p->nCursor );
assert( p->apCsr[i]!=0 );
if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
int rx, res;
rx = sqlite3BtreeMoveto(pCrsr, pTos->z, pTos->n, &res);
if( rx==SQLITE_OK && res==0 ){
rc = sqlite3BtreeDelete(pCrsr);
}
assert( pC->deferredMoveto==0 );
pC->cacheValid = 0;
}
Release(pTos);
pTos--;
break;
}
/* Opcode: IdxRowid P1 * *
**
** Push onto the stack an integer which is the last entry in the record at
** the end of the index key pointed to by cursor P1. This integer should be
** the rowid of the table entry to which this index entry points.
**
** See also: Rowid, MakeIdxKey.
*/
case OP_IdxRowid: {
int i = pOp->p1;
BtCursor *pCrsr;
Cursor *pC;
assert( i>=0 && i<p->nCursor );
assert( p->apCsr[i]!=0 );
pTos++;
pTos->flags = MEM_Null;
if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
i64 rowid;
assert( pC->deferredMoveto==0 );
assert( pC->isTable==0 );
if( pC->nullRow ){
pTos->flags = MEM_Null;
}else{
rc = sqlite3VdbeIdxRowid(pCrsr, &rowid);
if( rc!=SQLITE_OK ){
goto abort_due_to_error;
}
pTos->flags = MEM_Int;
pTos->i = rowid;
}
}
break;
}
/* Opcode: IdxGT P1 P2 *
**
** The top of the stack is an index entry that omits the ROWID. Compare
** the top of stack against the index that P1 is currently pointing to.
** Ignore the ROWID on the P1 index.
**
** The top of the stack might have fewer columns that P1.
**
** If the P1 index entry is greater than the top of the stack
** then jump to P2. Otherwise fall through to the next instruction.
** In either case, the stack is popped once.
*/
/* Opcode: IdxGE P1 P2 P3
**
** The top of the stack is an index entry that omits the ROWID. Compare
** the top of stack against the index that P1 is currently pointing to.
** Ignore the ROWID on the P1 index.
**
** If the P1 index entry is greater than or equal to the top of the stack
** then jump to P2. Otherwise fall through to the next instruction.
** In either case, the stack is popped once.
**
** If P3 is the "+" string (or any other non-NULL string) then the
** index taken from the top of the stack is temporarily increased by
** an epsilon prior to the comparison. This make the opcode work
** like IdxGT except that if the key from the stack is a prefix of
** the key in the cursor, the result is false whereas it would be
** true with IdxGT.
*/
/* Opcode: IdxLT P1 P2 P3
**
** The top of the stack is an index entry that omits the ROWID. Compare
** the top of stack against the index that P1 is currently pointing to.
** Ignore the ROWID on the P1 index.
**
** If the P1 index entry is less than the top of the stack
** then jump to P2. Otherwise fall through to the next instruction.
** In either case, the stack is popped once.
**
** If P3 is the "+" string (or any other non-NULL string) then the
** index taken from the top of the stack is temporarily increased by
** an epsilon prior to the comparison. This makes the opcode work
** like IdxLE.
*/
case OP_IdxLT: /* no-push */
case OP_IdxGT: /* no-push */
case OP_IdxGE: { /* no-push */
int i= pOp->p1;
Cursor *pC;
assert( i>=0 && i<p->nCursor );
assert( p->apCsr[i]!=0 );
assert( pTos>=p->aStack );
if( (pC = p->apCsr[i])->pCursor!=0 ){
int res, rc;
assert( pTos->flags & MEM_Blob ); /* Created using OP_Make*Key */
Stringify(pTos, db->enc);
assert( pC->deferredMoveto==0 );
*pC->pIncrKey = pOp->p3!=0;
assert( pOp->p3==0 || pOp->opcode!=OP_IdxGT );
rc = sqlite3VdbeIdxKeyCompare(pC, pTos->n, pTos->z, &res);
*pC->pIncrKey = 0;
if( rc!=SQLITE_OK ){
break;
}
if( pOp->opcode==OP_IdxLT ){
res = -res;
}else if( pOp->opcode==OP_IdxGE ){
res++;
}
if( res>0 ){
pc = pOp->p2 - 1 ;
}
}
Release(pTos);
pTos--;
break;
}
/* Opcode: IdxIsNull P1 P2 *
**
** The top of the stack contains an index entry such as might be generated
** by the MakeIdxKey opcode. This routine looks at the first P1 fields of
** that key. If any of the first P1 fields are NULL, then a jump is made
** to address P2. Otherwise we fall straight through.
**
** The index entry is always popped from the stack.
*/
case OP_IdxIsNull: { /* no-push */
int i = pOp->p1;
int k, n;
const char *z;
u32 serial_type;
assert( pTos>=p->aStack );
assert( pTos->flags & MEM_Blob );
z = pTos->z;
n = pTos->n;
k = sqlite3GetVarint32(z, &serial_type);
for(; k<n && i>0; i--){
k += sqlite3GetVarint32(&z[k], &serial_type);
if( serial_type==0 ){ /* Serial type 0 is a NULL */
pc = pOp->p2-1;
break;
}
}
Release(pTos);
pTos--;
break;
}
/* Opcode: Destroy P1 P2 *
**
** Delete an entire database table or index whose root page in the database
** file is given by P1.
**
** The table being destroyed is in the main database file if P2==0. If
** P2==1 then the table to be clear is in the auxiliary database file
** that is used to store tables create using CREATE TEMPORARY TABLE.
**
** If AUTOVACUUM is enabled then it is possible that another root page
** might be moved into the newly deleted root page in order to keep all
** root pages contiguous at the beginning of the database. The former
** value of the root page that moved - its value before the move occurred -
** is pushed onto the stack. If no page movement was required (because
** the table being dropped was already the last one in the database) then
** a zero is pushed onto the stack. If AUTOVACUUM is disabled
** then a zero is pushed onto the stack.
**
** See also: Clear
*/
case OP_Destroy: {
int iMoved;
if( db->activeVdbeCnt>1 ){
rc = SQLITE_LOCKED;
}else{
assert( db->activeVdbeCnt==1 );
rc = sqlite3BtreeDropTable(db->aDb[pOp->p2].pBt, pOp->p1, &iMoved);
pTos++;
pTos->flags = MEM_Int;
pTos->i = iMoved;
#ifndef SQLITE_OMIT_AUTOVACUUM
if( rc==SQLITE_OK && iMoved!=0 ){
sqlite3RootPageMoved(&db->aDb[pOp->p2], iMoved, pOp->p1);
}
#endif
}
break;
}
/* Opcode: Clear P1 P2 *
**
** Delete all contents of the database table or index whose root page
** in the database file is given by P1. But, unlike Destroy, do not
** remove the table or index from the database file.
**
** The table being clear is in the main database file if P2==0. If
** P2==1 then the table to be clear is in the auxiliary database file
** that is used to store tables create using CREATE TEMPORARY TABLE.
**
** See also: Destroy
*/
case OP_Clear: { /* no-push */
rc = sqlite3BtreeClearTable(db->aDb[pOp->p2].pBt, pOp->p1);
break;
}
/* Opcode: CreateTable P1 * *
**
** Allocate a new table in the main database file if P2==0 or in the
** auxiliary database file if P2==1. Push the page number
** for the root page of the new table onto the stack.
**
** The difference between a table and an index is this: A table must
** have a 4-byte integer key and can have arbitrary data. An index
** has an arbitrary key but no data.
**
** See also: CreateIndex
*/
/* Opcode: CreateIndex P1 * *
**
** Allocate a new index in the main database file if P2==0 or in the
** auxiliary database file if P2==1. Push the page number of the
** root page of the new index onto the stack.
**
** See documentation on OP_CreateTable for additional information.
*/
case OP_CreateIndex:
case OP_CreateTable: {
int pgno;
int flags;
Db *pDb;
assert( pOp->p1>=0 && pOp->p1<db->nDb );
pDb = &db->aDb[pOp->p1];
assert( pDb->pBt!=0 );
if( pOp->opcode==OP_CreateTable ){
/* flags = BTREE_INTKEY; */
flags = BTREE_LEAFDATA|BTREE_INTKEY;
}else{
flags = BTREE_ZERODATA;
}
rc = sqlite3BtreeCreateTable(pDb->pBt, &pgno, flags);
pTos++;
if( rc==SQLITE_OK ){
pTos->i = pgno;
pTos->flags = MEM_Int;
}else{
pTos->flags = MEM_Null;
}
break;
}
/* Opcode: ParseSchema P1 * P3
**
** Read and parse all entries from the SQLITE_MASTER table of database P1
** that match the WHERE clause P3.
**
** This opcode invokes the parser to create a new virtual machine,
** then runs the new virtual machine. It is thus a reentrant opcode.
*/
case OP_ParseSchema: { /* no-push */
char *zSql;
int iDb = pOp->p1;
const char *zMaster;
InitData initData;
assert( iDb>=0 && iDb<db->nDb );
if( !DbHasProperty(db, iDb, DB_SchemaLoaded) ) break;
zMaster = SCHEMA_TABLE(iDb);
initData.db = db;
initData.pzErrMsg = &p->zErrMsg;
zSql = sqlite3MPrintf(
"SELECT name, rootpage, sql, %d FROM '%q'.%s WHERE %s",
pOp->p1, db->aDb[iDb].zName, zMaster, pOp->p3);
if( zSql==0 ) goto no_mem;
sqlite3SafetyOff(db);
assert( db->init.busy==0 );
db->init.busy = 1;
rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
db->init.busy = 0;
sqlite3SafetyOn(db);
sqliteFree(zSql);
break;
}
#ifndef SQLITE_OMIT_ANALYZE
/* Opcode: LoadAnalysis P1 * *
**
** Read the sqlite_stat1 table for database P1 and load the content
** of that table into the internal index hash table. This will cause
** the analysis to be used when preparing all subsequent queries.
*/
case OP_LoadAnalysis: { /* no-push */
int iDb = pOp->p1;
assert( iDb>=0 && iDb<db->nDb );
sqlite3AnalysisLoad(db, iDb);
break;
}
#endif /* SQLITE_OMIT_ANALYZE */
/* Opcode: DropTable P1 * P3
**
** Remove the internal (in-memory) data structures that describe
** the table named P3 in database P1. This is called after a table
** is dropped in order to keep the internal representation of the
** schema consistent with what is on disk.
*/
case OP_DropTable: { /* no-push */
sqlite3UnlinkAndDeleteTable(db, pOp->p1, pOp->p3);
break;
}
/* Opcode: DropIndex P1 * P3
**
** Remove the internal (in-memory) data structures that describe
** the index named P3 in database P1. This is called after an index
** is dropped in order to keep the internal representation of the
** schema consistent with what is on disk.
*/
case OP_DropIndex: { /* no-push */
sqlite3UnlinkAndDeleteIndex(db, pOp->p1, pOp->p3);
break;
}
/* Opcode: DropTrigger P1 * P3
**
** Remove the internal (in-memory) data structures that describe
** the trigger named P3 in database P1. This is called after a trigger
** is dropped in order to keep the internal representation of the
** schema consistent with what is on disk.
*/
case OP_DropTrigger: { /* no-push */
sqlite3UnlinkAndDeleteTrigger(db, pOp->p1, pOp->p3);
break;
}
#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/* Opcode: IntegrityCk * P2 *
**
** Do an analysis of the currently open database. Push onto the
** stack the text of an error message describing any problems.
** If there are no errors, push a "ok" onto the stack.
**
** The root page numbers of all tables in the database are integer
** values on the stack. This opcode pulls as many integers as it
** can off of the stack and uses those numbers as the root pages.
**
** If P2 is not zero, the check is done on the auxiliary database
** file, not the main database file.
**
** This opcode is used for testing purposes only.
*/
case OP_IntegrityCk: {
int nRoot;
int *aRoot;
int j;
char *z;
for(nRoot=0; &pTos[-nRoot]>=p->aStack; nRoot++){
if( (pTos[-nRoot].flags & MEM_Int)==0 ) break;
}
assert( nRoot>0 );
aRoot = sqliteMallocRaw( sizeof(int*)*(nRoot+1) );
if( aRoot==0 ) goto no_mem;
for(j=0; j<nRoot; j++){
Mem *pMem = &pTos[-j];
aRoot[j] = pMem->i;
}
aRoot[j] = 0;
popStack(&pTos, nRoot);
pTos++;
z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p2].pBt, aRoot, nRoot);
if( z==0 || z[0]==0 ){
if( z ) sqliteFree(z);
pTos->z = "ok";
pTos->n = 2;
pTos->flags = MEM_Str | MEM_Static | MEM_Term;
}else{
pTos->z = z;
pTos->n = strlen(z);
pTos->flags = MEM_Str | MEM_Dyn | MEM_Term;
pTos->xDel = 0;
}
pTos->enc = SQLITE_UTF8;
sqlite3VdbeChangeEncoding(pTos, db->enc);
sqliteFree(aRoot);
break;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
/* Opcode: FifoWrite * * *
**
** Write the integer on the top of the stack
** into the Fifo.
*/
case OP_FifoWrite: { /* no-push */
assert( pTos>=p->aStack );
Integerify(pTos);
sqlite3VdbeFifoPush(&p->sFifo, pTos->i);
assert( (pTos->flags & MEM_Dyn)==0 );
pTos--;
break;
}
/* Opcode: FifoRead * P2 *
**
** Attempt to read a single integer from the Fifo
** and push it onto the stack. If the Fifo is empty
** push nothing but instead jump to P2.
*/
case OP_FifoRead: {
i64 v;
CHECK_FOR_INTERRUPT;
if( sqlite3VdbeFifoPop(&p->sFifo, &v)==SQLITE_DONE ){
pc = pOp->p2 - 1;
}else{
pTos++;
pTos->i = v;
pTos->flags = MEM_Int;
}
break;
}
#ifndef SQLITE_OMIT_TRIGGER
/* Opcode: ContextPush * * *
**
** Save the current Vdbe context such that it can be restored by a ContextPop
** opcode. The context stores the last insert row id, the last statement change
** count, and the current statement change count.
*/
case OP_ContextPush: { /* no-push */
int i = p->contextStackTop++;
Context *pContext;
assert( i>=0 );
/* FIX ME: This should be allocated as part of the vdbe at compile-time */
if( i>=p->contextStackDepth ){
p->contextStackDepth = i+1;
sqlite3ReallocOrFree((void**)&p->contextStack, sizeof(Context)*(i+1));
if( p->contextStack==0 ) goto no_mem;
}
pContext = &p->contextStack[i];
pContext->lastRowid = db->lastRowid;
pContext->nChange = p->nChange;
pContext->sFifo = p->sFifo;
sqlite3VdbeFifoInit(&p->sFifo);
break;
}
/* Opcode: ContextPop * * *
**
** Restore the Vdbe context to the state it was in when contextPush was last
** executed. The context stores the last insert row id, the last statement
** change count, and the current statement change count.
*/
case OP_ContextPop: { /* no-push */
Context *pContext = &p->contextStack[--p->contextStackTop];
assert( p->contextStackTop>=0 );
db->lastRowid = pContext->lastRowid;
p->nChange = pContext->nChange;
sqlite3VdbeFifoClear(&p->sFifo);
p->sFifo = pContext->sFifo;
break;
}
#endif /* #ifndef SQLITE_OMIT_TRIGGER */
/* Opcode: MemStore P1 P2 *
**
** Write the top of the stack into memory location P1.
** P1 should be a small integer since space is allocated
** for all memory locations between 0 and P1 inclusive.
**
** After the data is stored in the memory location, the
** stack is popped once if P2 is 1. If P2 is zero, then
** the original data remains on the stack.
*/
case OP_MemStore: { /* no-push */
assert( pTos>=p->aStack );
assert( pOp->p1>=0 && pOp->p1<p->nMem );
rc = sqlite3VdbeMemMove(&p->aMem[pOp->p1], pTos);
pTos--;
/* If P2 is 0 then fall thru to the next opcode, OP_MemLoad, that will
** restore the top of the stack to its original value.
*/
if( pOp->p2 ){
break;
}
}
/* Opcode: MemLoad P1 * *
**
** Push a copy of the value in memory location P1 onto the stack.
**
** If the value is a string, then the value pushed is a pointer to
** the string that is stored in the memory location. If the memory
** location is subsequently changed (using OP_MemStore) then the
** value pushed onto the stack will change too.
*/
case OP_MemLoad: {
int i = pOp->p1;
assert( i>=0 && i<p->nMem );
pTos++;
sqlite3VdbeMemShallowCopy(pTos, &p->aMem[i], MEM_Ephem);
break;
}
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* Opcode: MemMax P1 * *
**
** Set the value of memory cell P1 to the maximum of its current value
** and the value on the top of the stack. The stack is unchanged.
**
** This instruction throws an error if the memory cell is not initially
** an integer.
*/
case OP_MemMax: { /* no-push */
int i = pOp->p1;
Mem *pMem;
assert( pTos>=p->aStack );
assert( i>=0 && i<p->nMem );
pMem = &p->aMem[i];
Integerify(pMem);
Integerify(pTos);
if( pMem->i<pTos->i){
pMem->i = pTos->i;
}
break;
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */
/* Opcode: MemIncr P1 P2 *
**
** Increment the integer valued memory cell P1 by 1. If P2 is not zero
** and the result after the increment is exactly 1, then jump
** to P2.
**
** This instruction throws an error if the memory cell is not initially
** an integer.
*/
case OP_MemIncr: { /* no-push */
int i = pOp->p1;
Mem *pMem;
assert( i>=0 && i<p->nMem );
pMem = &p->aMem[i];
assert( pMem->flags==MEM_Int );
pMem->i++;
if( pOp->p2>0 && pMem->i==1 ){
pc = pOp->p2 - 1;
}
break;
}
/* Opcode: IfMemPos P1 P2 *
**
** If the value of memory cell P1 is 1 or greater, jump to P2. This
** opcode assumes that memory cell P1 holds an integer value.
*/
case OP_IfMemPos: { /* no-push */
int i = pOp->p1;
Mem *pMem;
assert( i>=0 && i<p->nMem );
pMem = &p->aMem[i];
assert( pMem->flags==MEM_Int );
if( pMem->i>0 ){
pc = pOp->p2 - 1;
}
break;
}
/* Opcode: MemNull P1 * *
**
** Store a NULL in memory cell P1
*/
case OP_MemNull: {
assert( pOp->p1>=0 && pOp->p1<p->nMem );
sqlite3VdbeMemSetNull(&p->aMem[pOp->p1]);
break;
}
/* Opcode: MemInt P1 P2 *
**
** Store the integer value P1 in memory cell P2.
*/
case OP_MemInt: {
assert( pOp->p2>=0 && pOp->p2<p->nMem );
sqlite3VdbeMemSetInt64(&p->aMem[pOp->p2], pOp->p1);
break;
}
/* Opcode: MemMove P1 P2 *
**
** Move the content of memory cell P2 over to memory cell P1.
** Any prior content of P1 is erased. Memory cell P2 is left
** containing a NULL.
*/
case OP_MemMove: {
assert( pOp->p1>=0 && pOp->p1<p->nMem );
assert( pOp->p2>=0 && pOp->p2<p->nMem );
rc = sqlite3VdbeMemMove(&p->aMem[pOp->p1], &p->aMem[pOp->p2]);
break;
}
/* Opcode: AggStep P1 P2 P3
**
** Execute the step function for an aggregate. The
** function has P2 arguments. P3 is a pointer to the FuncDef
** structure that specifies the function. Use memory location
** P1 as the accumulator.
**
** The P2 arguments are popped from the stack.
*/
case OP_AggStep: { /* no-push */
int n = pOp->p2;
int i;
Mem *pMem, *pRec;
sqlite3_context ctx;
sqlite3_value **apVal;
assert( n>=0 );
pRec = &pTos[1-n];
assert( pRec>=p->aStack );
apVal = p->apArg;
assert( apVal || n==0 );
for(i=0; i<n; i++, pRec++){
apVal[i] = pRec;
storeTypeInfo(pRec, db->enc);
}
ctx.pFunc = (FuncDef*)pOp->p3;
assert( pOp->p1>=0 && pOp->p1<p->nMem );
ctx.pMem = pMem = &p->aMem[pOp->p1];
pMem->n++;
ctx.isError = 0;
ctx.pColl = 0;
if( ctx.pFunc->needCollSeq ){
assert( pOp>p->aOp );
assert( pOp[-1].p3type==P3_COLLSEQ );
assert( pOp[-1].opcode==OP_CollSeq );
ctx.pColl = (CollSeq *)pOp[-1].p3;
}
(ctx.pFunc->xStep)(&ctx, n, apVal);
popStack(&pTos, n);
if( ctx.isError ){
rc = SQLITE_ERROR;
}
break;
}
/* Opcode: AggFinal P1 P2 P3
**
** Execute the finalizer function for an aggregate. P1 is
** the memory location that is the accumulator for the aggregate.
**
** P2 is the number of arguments that the step function takes and
** P3 is a pointer to the FuncDef for this function. The P2
** argument is not used by this opcode. It is only there to disambiguate
** functions that can take varying numbers of arguments. The
** P3 argument is only needed for the degenerate case where
** the step function was not previously called.
*/
case OP_AggFinal: { /* no-push */
Mem *pMem;
assert( pOp->p1>=0 && pOp->p1<p->nMem );
pMem = &p->aMem[pOp->p1];
assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
sqlite3VdbeMemFinalize(pMem, (FuncDef*)pOp->p3);
break;
}
/* Opcode: Vacuum * * *
**
** Vacuum the entire database. This opcode will cause other virtual
** machines to be created and run. It may not be called from within
** a transaction.
*/
case OP_Vacuum: { /* no-push */
if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
rc = sqlite3RunVacuum(&p->zErrMsg, db);
if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
break;
}
/* Opcode: Expire P1 * *
**
** Cause precompiled statements to become expired. An expired statement
** fails with an error code of SQLITE_SCHEMA if it is ever executed
** (via sqlite3_step()).
**
** If P1 is 0, then all SQL statements become expired. If P1 is non-zero,
** then only the currently executing statement is affected.
*/
case OP_Expire: { /* no-push */
if( !pOp->p1 ){
sqlite3ExpirePreparedStatements(db);
}else{
p->expired = 1;
}
break;
}
/* An other opcode is illegal...
*/
default: {
assert( 0 );
break;
}
/*****************************************************************************
** The cases of the switch statement above this line should all be indented
** by 6 spaces. But the left-most 6 spaces have been removed to improve the
** readability. From this point on down, the normal indentation rules are
** restored.
*****************************************************************************/
}
/* Make sure the stack limit was not exceeded */
assert( pTos<=pStackLimit );
#ifdef VDBE_PROFILE
{
long long elapse = hwtime() - start;
pOp->cycles += elapse;
pOp->cnt++;
#if 0
fprintf(stdout, "%10lld ", elapse);
sqlite3VdbePrintOp(stdout, origPc, &p->aOp[origPc]);
#endif
}
#endif
/* The following code adds nothing to the actual functionality
** of the program. It is only here for testing and debugging.
** On the other hand, it does burn CPU cycles every time through
** the evaluator loop. So we can leave it out when NDEBUG is defined.
*/
#ifndef NDEBUG
/* Sanity checking on the top element of the stack */
if( pTos>=p->aStack ){
sqlite3VdbeMemSanity(pTos, db->enc);
}
assert( pc>=-1 && pc<p->nOp );
#ifdef SQLITE_DEBUG
/* Code for tracing the vdbe stack. */
if( p->trace && pTos>=p->aStack ){
int i;
fprintf(p->trace, "Stack:");
for(i=0; i>-5 && &pTos[i]>=p->aStack; i--){
if( pTos[i].flags & MEM_Null ){
fprintf(p->trace, " NULL");
}else if( (pTos[i].flags & (MEM_Int|MEM_Str))==(MEM_Int|MEM_Str) ){
fprintf(p->trace, " si:%lld", pTos[i].i);
}else if( pTos[i].flags & MEM_Int ){
fprintf(p->trace, " i:%lld", pTos[i].i);
}else if( pTos[i].flags & MEM_Real ){
fprintf(p->trace, " r:%g", pTos[i].r);
}else{
char zBuf[100];
sqlite3VdbeMemPrettyPrint(&pTos[i], zBuf, 100);
fprintf(p->trace, " ");
fprintf(p->trace, "%s", zBuf);
}
}
if( rc!=0 ) fprintf(p->trace," rc=%d",rc);
fprintf(p->trace,"\n");
}
#endif /* SQLITE_DEBUG */
#endif /* NDEBUG */
} /* The end of the for(;;) loop the loops through opcodes */
/* If we reach this point, it means that execution is finished.
*/
vdbe_halt:
if( rc ){
p->rc = rc;
rc = SQLITE_ERROR;
}else{
rc = SQLITE_DONE;
}
sqlite3VdbeHalt(p);
p->pTos = pTos;
return rc;
/* Jump to here if a malloc() fails. It's hard to get a malloc()
** to fail on a modern VM computer, so this code is untested.
*/
no_mem:
sqlite3SetString(&p->zErrMsg, "out of memory", (char*)0);
rc = SQLITE_NOMEM;
goto vdbe_halt;
/* Jump to here for an SQLITE_MISUSE error.
*/
abort_due_to_misuse:
rc = SQLITE_MISUSE;
/* Fall thru into abort_due_to_error */
/* Jump to here for any other kind of fatal error. The "rc" variable
** should hold the error number.
*/
abort_due_to_error:
if( p->zErrMsg==0 ){
if( sqlite3_malloc_failed ) rc = SQLITE_NOMEM;
sqlite3SetString(&p->zErrMsg, sqlite3ErrStr(rc), (char*)0);
}
goto vdbe_halt;
/* Jump to here if the sqlite3_interrupt() API sets the interrupt
** flag.
*/
abort_due_to_interrupt:
assert( db->flags & SQLITE_Interrupt );
db->flags &= ~SQLITE_Interrupt;
if( db->magic!=SQLITE_MAGIC_BUSY ){
rc = SQLITE_MISUSE;
}else{
rc = SQLITE_INTERRUPT;
}
p->rc = rc;
sqlite3SetString(&p->zErrMsg, sqlite3ErrStr(rc), (char*)0);
goto vdbe_halt;
}