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1/*
2** 2001 September 15
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12** The code in this file implements execution method of the
13** Virtual Database Engine (VDBE). A separate file ("vdbeaux.c")
14** handles housekeeping details such as creating and deleting
15** VDBE instances. This file is solely interested in executing
16** the VDBE program.
17**
18** In the external interface, an "sqlite3_stmt*" is an opaque pointer
19** to a VDBE.
20**
21** The SQL parser generates a program which is then executed by
22** the VDBE to do the work of the SQL statement. VDBE programs are
23** similar in form to assembly language. The program consists of
24** a linear sequence of operations. Each operation has an opcode
25** and 3 operands. Operands P1 and P2 are integers. Operand P3
26** is a null-terminated string. The P2 operand must be non-negative.
27** Opcodes will typically ignore one or more operands. Many opcodes
28** ignore all three operands.
29**
30** Computation results are stored on a stack. Each entry on the
31** stack is either an integer, a null-terminated string, a floating point
32** number, or the SQL "NULL" value. An inplicit conversion from one
33** type to the other occurs as necessary.
34**
35** Most of the code in this file is taken up by the sqlite3VdbeExec()
36** function which does the work of interpreting a VDBE program.
37** But other routines are also provided to help in building up
38** a program instruction by instruction.
39**
40** Various scripts scan this source file in order to generate HTML
41** documentation, headers files, or other derived files. The formatting
42** of the code in this file is, therefore, important. See other comments
43** in this file for details. If in doubt, do not deviate from existing
44** commenting and indentation practices when changing or adding code.
45**
46** $Id: vdbe.c,v 1.650 2007/09/03 15:19:36 drh Exp $
47*/
48#include "sqliteInt.h"
49#include <ctype.h>
50#include <math.h>
51#include "vdbeInt.h"
52
53/*
54** The following global variable is incremented every time a cursor
55** moves, either by the OP_MoveXX, OP_Next, or OP_Prev opcodes. The test
56** procedures use this information to make sure that indices are
57** working correctly. This variable has no function other than to
58** help verify the correct operation of the library.
59*/
60#ifdef SQLITE_TEST
61int sqlite3_search_count = 0;
62#endif
63
64/*
65** When this global variable is positive, it gets decremented once before
66** each instruction in the VDBE. When reaches zero, the u1.isInterrupted
67** field of the sqlite3 structure is set in order to simulate and interrupt.
68**
69** This facility is used for testing purposes only. It does not function
70** in an ordinary build.
71*/
72#ifdef SQLITE_TEST
73int sqlite3_interrupt_count = 0;
74#endif
75
76/*
77** The next global variable is incremented each type the OP_Sort opcode
78** is executed. The test procedures use this information to make sure that
79** sorting is occurring or not occuring at appropriate times. This variable
80** has no function other than to help verify the correct operation of the
81** library.
82*/
83#ifdef SQLITE_TEST
84int sqlite3_sort_count = 0;
85#endif
86
87/*
88** The next global variable records the size of the largest MEM_Blob
89** or MEM_Str that has appeared on the VDBE stack. The test procedures
90** use this information to make sure that the zero-blob functionality
91** is working correctly. This variable has no function other than to
92** help verify the correct operation of the library.
93*/
94#ifdef SQLITE_TEST
95int sqlite3_max_blobsize = 0;
96#endif
97
98/*
99** Release the memory associated with the given stack level. This
100** leaves the Mem.flags field in an inconsistent state.
101*/
102#define Release(P) if((P)->flags&MEM_Dyn){ sqlite3VdbeMemRelease(P); }
103
104/*
105** Convert the given stack entity into a string if it isn't one
106** already. Return non-zero if a malloc() fails.
107*/
108#define Stringify(P, enc) \
109 if(((P)->flags&(MEM_Str|MEM_Blob))==0 && sqlite3VdbeMemStringify(P,enc)) \
110 { goto no_mem; }
111
112/*
113** The header of a record consists of a sequence variable-length integers.
114** These integers are almost always small and are encoded as a single byte.
115** The following macro takes advantage this fact to provide a fast decode
116** of the integers in a record header. It is faster for the common case
117** where the integer is a single byte. It is a little slower when the
118** integer is two or more bytes. But overall it is faster.
119**
120** The following expressions are equivalent:
121**
122** x = sqlite3GetVarint32( A, &B );
123**
124** x = GetVarint( A, B );
125**
126*/
127#define GetVarint(A,B) ((B = *(A))<=0x7f ? 1 : sqlite3GetVarint32(A, &B))
128
129/*
130** An ephemeral string value (signified by the MEM_Ephem flag) contains
131** a pointer to a dynamically allocated string where some other entity
132** is responsible for deallocating that string. Because the stack entry
133** does not control the string, it might be deleted without the stack
134** entry knowing it.
135**
136** This routine converts an ephemeral string into a dynamically allocated
137** string that the stack entry itself controls. In other words, it
138** converts an MEM_Ephem string into an MEM_Dyn string.
139*/
140#define Deephemeralize(P) \
141 if( ((P)->flags&MEM_Ephem)!=0 \
142 && sqlite3VdbeMemMakeWriteable(P) ){ goto no_mem;}
143
144/*
145** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
146** P if required.
147*/
148#define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
149
150/*
151** Argument pMem points at a memory cell that will be passed to a
152** user-defined function or returned to the user as the result of a query.
153** The second argument, 'db_enc' is the text encoding used by the vdbe for
154** stack variables. This routine sets the pMem->enc and pMem->type
155** variables used by the sqlite3_value_*() routines.
156*/
157#define storeTypeInfo(A,B) _storeTypeInfo(A)
158static void _storeTypeInfo(Mem *pMem){
159 int flags = pMem->flags;
160 if( flags & MEM_Null ){
161 pMem->type = SQLITE_NULL;
162 }
163 else if( flags & MEM_Int ){
164 pMem->type = SQLITE_INTEGER;
165 }
166 else if( flags & MEM_Real ){
167 pMem->type = SQLITE_FLOAT;
168 }
169 else if( flags & MEM_Str ){
170 pMem->type = SQLITE_TEXT;
171 }else{
172 pMem->type = SQLITE_BLOB;
173 }
174}
175
176/*
177** Pop the stack N times.
178*/
179static void popStack(Mem **ppTos, int N){
180 Mem *pTos = *ppTos;
181 while( N>0 ){
182 N--;
183 Release(pTos);
184 pTos--;
185 }
186 *ppTos = pTos;
187}
188
189/*
190** Allocate cursor number iCur. Return a pointer to it. Return NULL
191** if we run out of memory.
192*/
193static Cursor *allocateCursor(Vdbe *p, int iCur, int iDb){
194 Cursor *pCx;
195 assert( iCur<p->nCursor );
196 if( p->apCsr[iCur] ){
197 sqlite3VdbeFreeCursor(p, p->apCsr[iCur]);
198 }
199 p->apCsr[iCur] = pCx = sqlite3MallocZero( sizeof(Cursor) );
200 if( pCx ){
201 pCx->iDb = iDb;
202 }
203 return pCx;
204}
205
206/*
207** Try to convert a value into a numeric representation if we can
208** do so without loss of information. In other words, if the string
209** looks like a number, convert it into a number. If it does not
210** look like a number, leave it alone.
211*/
212static void applyNumericAffinity(Mem *pRec){
213 if( (pRec->flags & (MEM_Real|MEM_Int))==0 ){
214 int realnum;
215 sqlite3VdbeMemNulTerminate(pRec);
216 if( (pRec->flags&MEM_Str)
217 && sqlite3IsNumber(pRec->z, &realnum, pRec->enc) ){
218 i64 value;
219 sqlite3VdbeChangeEncoding(pRec, SQLITE_UTF8);
220 if( !realnum && sqlite3Atoi64(pRec->z, &value) ){
221 sqlite3VdbeMemRelease(pRec);
222 pRec->u.i = value;
223 pRec->flags = MEM_Int;
224 }else{
225 sqlite3VdbeMemRealify(pRec);
226 }
227 }
228 }
229}
230
231/*
232** Processing is determine by the affinity parameter:
233**
234** SQLITE_AFF_INTEGER:
235** SQLITE_AFF_REAL:
236** SQLITE_AFF_NUMERIC:
237** Try to convert pRec to an integer representation or a
238** floating-point representation if an integer representation
239** is not possible. Note that the integer representation is
240** always preferred, even if the affinity is REAL, because
241** an integer representation is more space efficient on disk.
242**
243** SQLITE_AFF_TEXT:
244** Convert pRec to a text representation.
245**
246** SQLITE_AFF_NONE:
247** No-op. pRec is unchanged.
248*/
249static void applyAffinity(
250 Mem *pRec, /* The value to apply affinity to */
251 char affinity, /* The affinity to be applied */
252 u8 enc /* Use this text encoding */
253){
254 if( affinity==SQLITE_AFF_TEXT ){
255 /* Only attempt the conversion to TEXT if there is an integer or real
256 ** representation (blob and NULL do not get converted) but no string
257 ** representation.
258 */
259 if( 0==(pRec->flags&MEM_Str) && (pRec->flags&(MEM_Real|MEM_Int)) ){
260 sqlite3VdbeMemStringify(pRec, enc);
261 }
262 pRec->flags &= ~(MEM_Real|MEM_Int);
263 }else if( affinity!=SQLITE_AFF_NONE ){
264 assert( affinity==SQLITE_AFF_INTEGER || affinity==SQLITE_AFF_REAL
265 || affinity==SQLITE_AFF_NUMERIC );
266 applyNumericAffinity(pRec);
267 if( pRec->flags & MEM_Real ){
268 sqlite3VdbeIntegerAffinity(pRec);
269 }
270 }
271}
272
273/*
274** Try to convert the type of a function argument or a result column
275** into a numeric representation. Use either INTEGER or REAL whichever
276** is appropriate. But only do the conversion if it is possible without
277** loss of information and return the revised type of the argument.
278**
279** This is an EXPERIMENTAL api and is subject to change or removal.
280*/
281int sqlite3_value_numeric_type(sqlite3_value *pVal){
282 Mem *pMem = (Mem*)pVal;
283 applyNumericAffinity(pMem);
284 storeTypeInfo(pMem, 0);
285 return pMem->type;
286}
287
288/*
289** Exported version of applyAffinity(). This one works on sqlite3_value*,
290** not the internal Mem* type.
291*/
292void sqlite3ValueApplyAffinity(
293 sqlite3_value *pVal,
294 u8 affinity,
295 u8 enc
296){
297 applyAffinity((Mem *)pVal, affinity, enc);
298}
299
300#ifdef SQLITE_DEBUG
301/*
302** Write a nice string representation of the contents of cell pMem
303** into buffer zBuf, length nBuf.
304*/
305void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf){
306 char *zCsr = zBuf;
307 int f = pMem->flags;
308
309 static const char *const encnames[] = {"(X)", "(8)", "(16LE)", "(16BE)"};
310
311 if( f&MEM_Blob ){
312 int i;
313 char c;
314 if( f & MEM_Dyn ){
315 c = 'z';
316 assert( (f & (MEM_Static|MEM_Ephem))==0 );
317 }else if( f & MEM_Static ){
318 c = 't';
319 assert( (f & (MEM_Dyn|MEM_Ephem))==0 );
320 }else if( f & MEM_Ephem ){
321 c = 'e';
322 assert( (f & (MEM_Static|MEM_Dyn))==0 );
323 }else{
324 c = 's';
325 }
326
327 sqlite3_snprintf(100, zCsr, "%c", c);
328 zCsr += strlen(zCsr);
329 sqlite3_snprintf(100, zCsr, "%d[", pMem->n);
330 zCsr += strlen(zCsr);
331 for(i=0; i<16 && i<pMem->n; i++){
332 sqlite3_snprintf(100, zCsr, "%02X", ((int)pMem->z[i] & 0xFF));
333 zCsr += strlen(zCsr);
334 }
335 for(i=0; i<16 && i<pMem->n; i++){
336 char z = pMem->z[i];
337 if( z<32 || z>126 ) *zCsr++ = '.';
338 else *zCsr++ = z;
339 }
340
341 sqlite3_snprintf(100, zCsr, "]%s", encnames[pMem->enc]);
342 zCsr += strlen(zCsr);
343 if( f & MEM_Zero ){
344 sqlite3_snprintf(100, zCsr,"+%lldz",pMem->u.i);
345 zCsr += strlen(zCsr);
346 }
347 *zCsr = '\0';
348 }else if( f & MEM_Str ){
349 int j, k;
350 zBuf[0] = ' ';
351 if( f & MEM_Dyn ){
352 zBuf[1] = 'z';
353 assert( (f & (MEM_Static|MEM_Ephem))==0 );
354 }else if( f & MEM_Static ){
355 zBuf[1] = 't';
356 assert( (f & (MEM_Dyn|MEM_Ephem))==0 );
357 }else if( f & MEM_Ephem ){
358 zBuf[1] = 'e';
359 assert( (f & (MEM_Static|MEM_Dyn))==0 );
360 }else{
361 zBuf[1] = 's';
362 }
363 k = 2;
364 sqlite3_snprintf(100, &zBuf[k], "%d", pMem->n);
365 k += strlen(&zBuf[k]);
366 zBuf[k++] = '[';
367 for(j=0; j<15 && j<pMem->n; j++){
368 u8 c = pMem->z[j];
369 if( c>=0x20 && c<0x7f ){
370 zBuf[k++] = c;
371 }else{
372 zBuf[k++] = '.';
373 }
374 }
375 zBuf[k++] = ']';
376 sqlite3_snprintf(100,&zBuf[k], encnames[pMem->enc]);
377 k += strlen(&zBuf[k]);
378 zBuf[k++] = 0;
379 }
380}
381#endif
382
383
384#ifdef VDBE_PROFILE
385/*
386** The following routine only works on pentium-class processors.
387** It uses the RDTSC opcode to read the cycle count value out of the
388** processor and returns that value. This can be used for high-res
389** profiling.
390*/
391__inline__ unsigned long long int hwtime(void){
392 unsigned long long int x;
393 __asm__("rdtsc\n\t"
394 "mov %%edx, %%ecx\n\t"
395 :"=A" (x));
396 return x;
397}
398#endif
399
400/*
401** The CHECK_FOR_INTERRUPT macro defined here looks to see if the
402** sqlite3_interrupt() routine has been called. If it has been, then
403** processing of the VDBE program is interrupted.
404**
405** This macro added to every instruction that does a jump in order to
406** implement a loop. This test used to be on every single instruction,
407** but that meant we more testing that we needed. By only testing the
408** flag on jump instructions, we get a (small) speed improvement.
409*/
410#define CHECK_FOR_INTERRUPT \
411 if( db->u1.isInterrupted ) goto abort_due_to_interrupt;
412
413
414/*
415** Execute as much of a VDBE program as we can then return.
416**
417** sqlite3VdbeMakeReady() must be called before this routine in order to
418** close the program with a final OP_Halt and to set up the callbacks
419** and the error message pointer.
420**
421** Whenever a row or result data is available, this routine will either
422** invoke the result callback (if there is one) or return with
423** SQLITE_ROW.
424**
425** If an attempt is made to open a locked database, then this routine
426** will either invoke the busy callback (if there is one) or it will
427** return SQLITE_BUSY.
428**
429** If an error occurs, an error message is written to memory obtained
430** from sqlite3_malloc() and p->zErrMsg is made to point to that memory.
431** The error code is stored in p->rc and this routine returns SQLITE_ERROR.
432**
433** If the callback ever returns non-zero, then the program exits
434** immediately. There will be no error message but the p->rc field is
435** set to SQLITE_ABORT and this routine will return SQLITE_ERROR.
436**
437** A memory allocation error causes p->rc to be set to SQLITE_NOMEM and this
438** routine to return SQLITE_ERROR.
439**
440** Other fatal errors return SQLITE_ERROR.
441**
442** After this routine has finished, sqlite3VdbeFinalize() should be
443** used to clean up the mess that was left behind.
444*/
445int sqlite3VdbeExec(
446 Vdbe *p /* The VDBE */
447){
448 int pc; /* The program counter */
449 Op *pOp; /* Current operation */
450 int rc = SQLITE_OK; /* Value to return */
451 sqlite3 *db = p->db; /* The database */
452 u8 encoding = ENC(db); /* The database encoding */
453 Mem *pTos; /* Top entry in the operand stack */
454#ifdef VDBE_PROFILE
455 unsigned long long start; /* CPU clock count at start of opcode */
456 int origPc; /* Program counter at start of opcode */
457#endif
458#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
459 int nProgressOps = 0; /* Opcodes executed since progress callback. */
460#endif
461#ifndef NDEBUG
462 Mem *pStackLimit;
463#endif
464
465 if( p->magic!=VDBE_MAGIC_RUN ) return SQLITE_MISUSE;
466 assert( db->magic==SQLITE_MAGIC_BUSY );
467 pTos = p->pTos;
468 sqlite3BtreeMutexArrayEnter(&p->aMutex);
469 if( p->rc==SQLITE_NOMEM ){
470 /* This happens if a malloc() inside a call to sqlite3_column_text() or
471 ** sqlite3_column_text16() failed. */
472 goto no_mem;
473 }
474 assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY );
475 p->rc = SQLITE_OK;
476 assert( p->explain==0 );
477 if( p->popStack ){
478 popStack(&pTos, p->popStack);
479 p->popStack = 0;
480 }
481 p->resOnStack = 0;
482 db->busyHandler.nBusy = 0;
483 CHECK_FOR_INTERRUPT;
484 sqlite3VdbeIOTraceSql(p);
485#ifdef SQLITE_DEBUG
486 if( (p->db->flags & SQLITE_VdbeListing)!=0
487 || sqlite3OsAccess(db->pVfs, "vdbe_explain", SQLITE_ACCESS_EXISTS)
488 ){
489 int i;
490 printf("VDBE Program Listing:\n");
491 sqlite3VdbePrintSql(p);
492 for(i=0; i<p->nOp; i++){
493 sqlite3VdbePrintOp(stdout, i, &p->aOp[i]);
494 }
495 }
496 if( sqlite3OsAccess(db->pVfs, "vdbe_trace", SQLITE_ACCESS_EXISTS) ){
497 p->trace = stdout;
498 }
499#endif
500 for(pc=p->pc; rc==SQLITE_OK; pc++){
501 assert( pc>=0 && pc<p->nOp );
502 assert( pTos<=&p->aStack[pc] );
503 if( db->mallocFailed ) goto no_mem;
504#ifdef VDBE_PROFILE
505 origPc = pc;
506 start = hwtime();
507#endif
508 pOp = &p->aOp[pc];
509
510 /* Only allow tracing if SQLITE_DEBUG is defined.
511 */
512#ifdef SQLITE_DEBUG
513 if( p->trace ){
514 if( pc==0 ){
515 printf("VDBE Execution Trace:\n");
516 sqlite3VdbePrintSql(p);
517 }
518 sqlite3VdbePrintOp(p->trace, pc, pOp);
519 }
520 if( p->trace==0 && pc==0
521 && sqlite3OsAccess(db->pVfs, "vdbe_sqltrace", SQLITE_ACCESS_EXISTS) ){
522 sqlite3VdbePrintSql(p);
523 }
524#endif
525
526
527 /* Check to see if we need to simulate an interrupt. This only happens
528 ** if we have a special test build.
529 */
530#ifdef SQLITE_TEST
531 if( sqlite3_interrupt_count>0 ){
532 sqlite3_interrupt_count--;
533 if( sqlite3_interrupt_count==0 ){
534 sqlite3_interrupt(db);
535 }
536 }
537#endif
538
539#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
540 /* Call the progress callback if it is configured and the required number
541 ** of VDBE ops have been executed (either since this invocation of
542 ** sqlite3VdbeExec() or since last time the progress callback was called).
543 ** If the progress callback returns non-zero, exit the virtual machine with
544 ** a return code SQLITE_ABORT.
545 */
546 if( db->xProgress ){
547 if( db->nProgressOps==nProgressOps ){
548 int prc;
549 if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
550 prc =db->xProgress(db->pProgressArg);
551 if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
552 if( prc!=0 ){
553 rc = SQLITE_INTERRUPT;
554 goto vdbe_halt;
555 }
556 nProgressOps = 0;
557 }
558 nProgressOps++;
559 }
560#endif
561
562#ifndef NDEBUG
563 /* This is to check that the return value of static function
564 ** opcodeNoPush() (see vdbeaux.c) returns values that match the
565 ** implementation of the virtual machine in this file. If
566 ** opcodeNoPush() returns non-zero, then the stack is guarenteed
567 ** not to grow when the opcode is executed. If it returns zero, then
568 ** the stack may grow by at most 1.
569 **
570 ** The global wrapper function sqlite3VdbeOpcodeUsesStack() is not
571 ** available if NDEBUG is defined at build time.
572 */
573 pStackLimit = pTos;
574 if( !sqlite3VdbeOpcodeNoPush(pOp->opcode) ){
575 pStackLimit++;
576 }
577#endif
578
579 switch( pOp->opcode ){
580
581/*****************************************************************************
582** What follows is a massive switch statement where each case implements a
583** separate instruction in the virtual machine. If we follow the usual
584** indentation conventions, each case should be indented by 6 spaces. But
585** that is a lot of wasted space on the left margin. So the code within
586** the switch statement will break with convention and be flush-left. Another
587** big comment (similar to this one) will mark the point in the code where
588** we transition back to normal indentation.
589**
590** The formatting of each case is important. The makefile for SQLite
591** generates two C files "opcodes.h" and "opcodes.c" by scanning this
592** file looking for lines that begin with "case OP_". The opcodes.h files
593** will be filled with #defines that give unique integer values to each
594** opcode and the opcodes.c file is filled with an array of strings where
595** each string is the symbolic name for the corresponding opcode. If the
596** case statement is followed by a comment of the form "/# same as ... #/"
597** that comment is used to determine the particular value of the opcode.
598**
599** If a comment on the same line as the "case OP_" construction contains
600** the word "no-push", then the opcode is guarenteed not to grow the
601** vdbe stack when it is executed. See function opcode() in
602** vdbeaux.c for details.
603**
604** Documentation about VDBE opcodes is generated by scanning this file
605** for lines of that contain "Opcode:". That line and all subsequent
606** comment lines are used in the generation of the opcode.html documentation
607** file.
608**
609** SUMMARY:
610**
611** Formatting is important to scripts that scan this file.
612** Do not deviate from the formatting style currently in use.
613**
614*****************************************************************************/
615
616/* Opcode: Goto * P2 *
617**
618** An unconditional jump to address P2.
619** The next instruction executed will be
620** the one at index P2 from the beginning of
621** the program.
622*/
623case OP_Goto: { /* no-push */
624 CHECK_FOR_INTERRUPT;
625 pc = pOp->p2 - 1;
626 break;
627}
628
629/* Opcode: Gosub * P2 *
630**
631** Push the current address plus 1 onto the return address stack
632** and then jump to address P2.
633**
634** The return address stack is of limited depth. If too many
635** OP_Gosub operations occur without intervening OP_Returns, then
636** the return address stack will fill up and processing will abort
637** with a fatal error.
638*/
639case OP_Gosub: { /* no-push */
640 assert( p->returnDepth<sizeof(p->returnStack)/sizeof(p->returnStack[0]) );
641 p->returnStack[p->returnDepth++] = pc+1;
642 pc = pOp->p2 - 1;
643 break;
644}
645
646/* Opcode: Return * * *
647**
648** Jump immediately to the next instruction after the last unreturned
649** OP_Gosub. If an OP_Return has occurred for all OP_Gosubs, then
650** processing aborts with a fatal error.
651*/
652case OP_Return: { /* no-push */
653 assert( p->returnDepth>0 );
654 p->returnDepth--;
655 pc = p->returnStack[p->returnDepth] - 1;
656 break;
657}
658
659/* Opcode: Halt P1 P2 P3
660**
661** Exit immediately. All open cursors, Fifos, etc are closed
662** automatically.
663**
664** P1 is the result code returned by sqlite3_exec(), sqlite3_reset(),
665** or sqlite3_finalize(). For a normal halt, this should be SQLITE_OK (0).
666** For errors, it can be some other value. If P1!=0 then P2 will determine
667** whether or not to rollback the current transaction. Do not rollback
668** if P2==OE_Fail. Do the rollback if P2==OE_Rollback. If P2==OE_Abort,
669** then back out all changes that have occurred during this execution of the
670** VDBE, but do not rollback the transaction.
671**
672** If P3 is not null then it is an error message string.
673**
674** There is an implied "Halt 0 0 0" instruction inserted at the very end of
675** every program. So a jump past the last instruction of the program
676** is the same as executing Halt.
677*/
678case OP_Halt: { /* no-push */
679 p->pTos = pTos;
680 p->rc = pOp->p1;
681 p->pc = pc;
682 p->errorAction = pOp->p2;
683 if( pOp->p3 ){
684 sqlite3SetString(&p->zErrMsg, pOp->p3, (char*)0);
685 }
686 rc = sqlite3VdbeHalt(p);
687 assert( rc==SQLITE_BUSY || rc==SQLITE_OK );
688 if( rc==SQLITE_BUSY ){
689 p->rc = rc = SQLITE_BUSY;
690 }else{
691 rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;
692 }
693 goto vdbe_return;
694}
695
696/* Opcode: Integer P1 * *
697**
698** The 32-bit integer value P1 is pushed onto the stack.
699*/
700case OP_Integer: {
701 pTos++;
702 pTos->flags = MEM_Int;
703 pTos->u.i = pOp->p1;
704 break;
705}
706
707/* Opcode: Int64 * * P3
708**
709** P3 is a string representation of an integer. Convert that integer
710** to a 64-bit value and push it onto the stack.
711*/
712case OP_Int64: {
713 pTos++;
714 assert( pOp->p3!=0 );
715 pTos->flags = MEM_Str|MEM_Static|MEM_Term;
716 pTos->z = pOp->p3;
717 pTos->n = strlen(pTos->z);
718 pTos->enc = SQLITE_UTF8;
719 pTos->u.i = sqlite3VdbeIntValue(pTos);
720 pTos->flags |= MEM_Int;
721 break;
722}
723
724/* Opcode: Real * * P3
725**
726** The string value P3 is converted to a real and pushed on to the stack.
727*/
728case OP_Real: { /* same as TK_FLOAT, */
729 pTos++;
730 pTos->flags = MEM_Str|MEM_Static|MEM_Term;
731 pTos->z = pOp->p3;
732 pTos->n = strlen(pTos->z);
733 pTos->enc = SQLITE_UTF8;
734 pTos->r = sqlite3VdbeRealValue(pTos);
735 pTos->flags |= MEM_Real;
736 sqlite3VdbeChangeEncoding(pTos, encoding);
737 break;
738}
739
740/* Opcode: String8 * * P3
741**
742** P3 points to a nul terminated UTF-8 string. This opcode is transformed
743** into an OP_String before it is executed for the first time.
744*/
745case OP_String8: { /* same as TK_STRING */
746 assert( pOp->p3!=0 );
747 pOp->opcode = OP_String;
748 pOp->p1 = strlen(pOp->p3);
749 assert( SQLITE_MAX_SQL_LENGTH < SQLITE_MAX_LENGTH );
750 assert( pOp->p1 < SQLITE_MAX_LENGTH );
751
752#ifndef SQLITE_OMIT_UTF16
753 if( encoding!=SQLITE_UTF8 ){
754 pTos++;
755 sqlite3VdbeMemSetStr(pTos, pOp->p3, -1, SQLITE_UTF8, SQLITE_STATIC);
756 if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pTos, encoding) ) goto no_mem;
757 if( SQLITE_OK!=sqlite3VdbeMemDynamicify(pTos) ) goto no_mem;
758 pTos->flags &= ~(MEM_Dyn);
759 pTos->flags |= MEM_Static;
760 if( pOp->p3type==P3_DYNAMIC ){
761 sqlite3_free(pOp->p3);
762 }
763 pOp->p3type = P3_DYNAMIC;
764 pOp->p3 = pTos->z;
765 pOp->p1 = pTos->n;
766 assert( pOp->p1 < SQLITE_MAX_LENGTH ); /* Due to SQLITE_MAX_SQL_LENGTH */
767 break;
768 }
769#endif
770 /* Otherwise fall through to the next case, OP_String */
771}
772
773/* Opcode: String P1 * P3
774**
775** The string value P3 of length P1 (bytes) is pushed onto the stack.
776*/
777case OP_String: {
778 assert( pOp->p1 < SQLITE_MAX_LENGTH ); /* Due to SQLITE_MAX_SQL_LENGTH */
779 pTos++;
780 assert( pOp->p3!=0 );
781 pTos->flags = MEM_Str|MEM_Static|MEM_Term;
782 pTos->z = pOp->p3;
783 pTos->n = pOp->p1;
784 pTos->enc = encoding;
785 break;
786}
787
788/* Opcode: Null * * *
789**
790** Push a NULL onto the stack.
791*/
792case OP_Null: {
793 pTos++;
794 pTos->flags = MEM_Null;
795 pTos->n = 0;
796 break;
797}
798
799
800#ifndef SQLITE_OMIT_BLOB_LITERAL
801/* Opcode: HexBlob * * P3
802**
803** P3 is an UTF-8 SQL hex encoding of a blob. The blob is pushed onto the
804** vdbe stack.
805**
806** The first time this instruction executes, in transforms itself into a
807** 'Blob' opcode with a binary blob as P3.
808*/
809case OP_HexBlob: { /* same as TK_BLOB */
810 pOp->opcode = OP_Blob;
811 pOp->p1 = strlen(pOp->p3)/2;
812 assert( SQLITE_MAX_SQL_LENGTH < SQLITE_MAX_LENGTH );
813 assert( pOp->p1 < SQLITE_MAX_LENGTH );
814 if( pOp->p1 ){
815 char *zBlob = sqlite3HexToBlob(db, pOp->p3);
816 if( !zBlob ) goto no_mem;
817 if( pOp->p3type==P3_DYNAMIC ){
818 sqlite3_free(pOp->p3);
819 }
820 pOp->p3 = zBlob;
821 pOp->p3type = P3_DYNAMIC;
822 }else{
823 if( pOp->p3type==P3_DYNAMIC ){
824 sqlite3_free(pOp->p3);
825 }
826 pOp->p3type = P3_STATIC;
827 pOp->p3 = "";
828 }
829
830 /* Fall through to the next case, OP_Blob. */
831}
832
833/* Opcode: Blob P1 * P3
834**
835** P3 points to a blob of data P1 bytes long. Push this
836** value onto the stack. This instruction is not coded directly
837** by the compiler. Instead, the compiler layer specifies
838** an OP_HexBlob opcode, with the hex string representation of
839** the blob as P3. This opcode is transformed to an OP_Blob
840** the first time it is executed.
841*/
842case OP_Blob: {
843 pTos++;
844 assert( pOp->p1 < SQLITE_MAX_LENGTH ); /* Due to SQLITE_MAX_SQL_LENGTH */
845 sqlite3VdbeMemSetStr(pTos, pOp->p3, pOp->p1, 0, 0);
846 pTos->enc = encoding;
847 break;
848}
849#endif /* SQLITE_OMIT_BLOB_LITERAL */
850
851/* Opcode: Variable P1 * *
852**
853** Push the value of variable P1 onto the stack. A variable is
854** an unknown in the original SQL string as handed to sqlite3_compile().
855** Any occurance of the '?' character in the original SQL is considered
856** a variable. Variables in the SQL string are number from left to
857** right beginning with 1. The values of variables are set using the
858** sqlite3_bind() API.
859*/
860case OP_Variable: {
861 int j = pOp->p1 - 1;
862 Mem *pVar;
863 assert( j>=0 && j<p->nVar );
864
865 pVar = &p->aVar[j];
866 if( sqlite3VdbeMemTooBig(pVar) ){
867 goto too_big;
868 }
869 pTos++;
870 sqlite3VdbeMemShallowCopy(pTos, &p->aVar[j], MEM_Static);
871 break;
872}
873
874/* Opcode: Pop P1 * *
875**
876** P1 elements are popped off of the top of stack and discarded.
877*/
878case OP_Pop: { /* no-push */
879 assert( pOp->p1>=0 );
880 popStack(&pTos, pOp->p1);
881 assert( pTos>=&p->aStack[-1] );
882 break;
883}
884
885/* Opcode: Dup P1 P2 *
886**
887** A copy of the P1-th element of the stack
888** is made and pushed onto the top of the stack.
889** The top of the stack is element 0. So the
890** instruction "Dup 0 0 0" will make a copy of the
891** top of the stack.
892**
893** If the content of the P1-th element is a dynamically
894** allocated string, then a new copy of that string
895** is made if P2==0. If P2!=0, then just a pointer
896** to the string is copied.
897**
898** Also see the Pull instruction.
899*/
900case OP_Dup: {
901 Mem *pFrom = &pTos[-pOp->p1];
902 assert( pFrom<=pTos && pFrom>=p->aStack );
903 pTos++;
904 sqlite3VdbeMemShallowCopy(pTos, pFrom, MEM_Ephem);
905 if( pOp->p2 ){
906 Deephemeralize(pTos);
907 }
908 break;
909}
910
911/* Opcode: Pull P1 * *
912**
913** The P1-th element is removed from its current location on
914** the stack and pushed back on top of the stack. The
915** top of the stack is element 0, so "Pull 0 0 0" is
916** a no-op. "Pull 1 0 0" swaps the top two elements of
917** the stack.
918**
919** See also the Dup instruction.
920*/
921case OP_Pull: { /* no-push */
922 Mem *pFrom = &pTos[-pOp->p1];
923 int i;
924 Mem ts;
925
926 ts = *pFrom;
927 Deephemeralize(pTos);
928 for(i=0; i<pOp->p1; i++, pFrom++){
929 Deephemeralize(&pFrom[1]);
930 assert( (pFrom[1].flags & MEM_Ephem)==0 );
931 *pFrom = pFrom[1];
932 if( pFrom->flags & MEM_Short ){
933 assert( pFrom->flags & (MEM_Str|MEM_Blob) );
934 assert( pFrom->z==pFrom[1].zShort );
935 pFrom->z = pFrom->zShort;
936 }
937 }
938 *pTos = ts;
939 if( pTos->flags & MEM_Short ){
940 assert( pTos->flags & (MEM_Str|MEM_Blob) );
941 assert( pTos->z==pTos[-pOp->p1].zShort );
942 pTos->z = pTos->zShort;
943 }
944 break;
945}
946
947/* Opcode: Push P1 * *
948**
949** Overwrite the value of the P1-th element down on the
950** stack (P1==0 is the top of the stack) with the value
951** of the top of the stack. Then pop the top of the stack.
952*/
953case OP_Push: { /* no-push */
954 Mem *pTo = &pTos[-pOp->p1];
955
956 assert( pTo>=p->aStack );
957 sqlite3VdbeMemMove(pTo, pTos);
958 pTos--;
959 break;
960}
961
962/* Opcode: Callback P1 * *
963**
964** The top P1 values on the stack represent a single result row from
965** a query. This opcode causes the sqlite3_step() call to terminate
966** with an SQLITE_ROW return code and it sets up the sqlite3_stmt
967** structure to provide access to the top P1 values as the result
968** row. When the sqlite3_step() function is run again, the top P1
969** values will be automatically popped from the stack before the next
970** instruction executes.
971*/
972case OP_Callback: { /* no-push */
973 Mem *pMem;
974 Mem *pFirstColumn;
975 assert( p->nResColumn==pOp->p1 );
976
977 /* Data in the pager might be moved or changed out from under us
978 ** in between the return from this sqlite3_step() call and the
979 ** next call to sqlite3_step(). So deephermeralize everything on
980 ** the stack. Note that ephemeral data is never stored in memory
981 ** cells so we do not have to worry about them.
982 */
983 pFirstColumn = &pTos[0-pOp->p1];
984 for(pMem = p->aStack; pMem<pFirstColumn; pMem++){
985 Deephemeralize(pMem);
986 }
987
988 /* Invalidate all ephemeral cursor row caches */
989 p->cacheCtr = (p->cacheCtr + 2)|1;
990
991 /* Make sure the results of the current row are \000 terminated
992 ** and have an assigned type. The results are deephemeralized as
993 ** as side effect.
994 */
995 for(; pMem<=pTos; pMem++ ){
996 sqlite3VdbeMemNulTerminate(pMem);
997 storeTypeInfo(pMem, encoding);
998 }
999
1000 /* Set up the statement structure so that it will pop the current
1001 ** results from the stack when the statement returns.
1002 */
1003 p->resOnStack = 1;
1004 p->nCallback++;
1005 p->popStack = pOp->p1;
1006 p->pc = pc + 1;
1007 p->pTos = pTos;
1008 rc = SQLITE_ROW;
1009 goto vdbe_return;
1010}
1011
1012/* Opcode: Concat P1 P2 *
1013**
1014** Look at the first P1+2 elements of the stack. Append them all
1015** together with the lowest element first. The original P1+2 elements
1016** are popped from the stack if P2==0 and retained if P2==1. If
1017** any element of the stack is NULL, then the result is NULL.
1018**
1019** When P1==1, this routine makes a copy of the top stack element
1020** into memory obtained from sqlite3_malloc().
1021*/
1022case OP_Concat: { /* same as TK_CONCAT */
1023 char *zNew;
1024 i64 nByte;
1025 int nField;
1026 int i, j;
1027 Mem *pTerm;
1028
1029 /* Loop through the stack elements to see how long the result will be. */
1030 nField = pOp->p1 + 2;
1031 pTerm = &pTos[1-nField];
1032 nByte = 0;
1033 for(i=0; i<nField; i++, pTerm++){
1034 assert( pOp->p2==0 || (pTerm->flags&MEM_Str) );
1035 if( pTerm->flags&MEM_Null ){
1036 nByte = -1;
1037 break;
1038 }
1039 ExpandBlob(pTerm);
1040 Stringify(pTerm, encoding);
1041 nByte += pTerm->n;
1042 }
1043
1044 if( nByte<0 ){
1045 /* If nByte is less than zero, then there is a NULL value on the stack.
1046 ** In this case just pop the values off the stack (if required) and
1047 ** push on a NULL.
1048 */
1049 if( pOp->p2==0 ){
1050 popStack(&pTos, nField);
1051 }
1052 pTos++;
1053 pTos->flags = MEM_Null;
1054 }else{
1055 /* Otherwise malloc() space for the result and concatenate all the
1056 ** stack values.
1057 */
1058 if( nByte+2>SQLITE_MAX_LENGTH ){
1059 goto too_big;
1060 }
1061 zNew = sqlite3DbMallocRaw(db, nByte+2 );
1062 if( zNew==0 ) goto no_mem;
1063 j = 0;
1064 pTerm = &pTos[1-nField];
1065 for(i=j=0; i<nField; i++, pTerm++){
1066 int n = pTerm->n;
1067 assert( pTerm->flags & (MEM_Str|MEM_Blob) );
1068 memcpy(&zNew[j], pTerm->z, n);
1069 j += n;
1070 }
1071 zNew[j] = 0;
1072 zNew[j+1] = 0;
1073 assert( j==nByte );
1074
1075 if( pOp->p2==0 ){
1076 popStack(&pTos, nField);
1077 }
1078 pTos++;
1079 pTos->n = j;
1080 pTos->flags = MEM_Str|MEM_Dyn|MEM_Term;
1081 pTos->xDel = 0;
1082 pTos->enc = encoding;
1083 pTos->z = zNew;
1084 }
1085 break;
1086}
1087
1088/* Opcode: Add * * *
1089**
1090** Pop the top two elements from the stack, add them together,
1091** and push the result back onto the stack. If either element
1092** is a string then it is converted to a double using the atof()
1093** function before the addition.
1094** If either operand is NULL, the result is NULL.
1095*/
1096/* Opcode: Multiply * * *
1097**
1098** Pop the top two elements from the stack, multiply them together,
1099** and push the result back onto the stack. If either element
1100** is a string then it is converted to a double using the atof()
1101** function before the multiplication.
1102** If either operand is NULL, the result is NULL.
1103*/
1104/* Opcode: Subtract * * *
1105**
1106** Pop the top two elements from the stack, subtract the
1107** first (what was on top of the stack) from the second (the
1108** next on stack)
1109** and push the result back onto the stack. If either element
1110** is a string then it is converted to a double using the atof()
1111** function before the subtraction.
1112** If either operand is NULL, the result is NULL.
1113*/
1114/* Opcode: Divide * * *
1115**
1116** Pop the top two elements from the stack, divide the
1117** first (what was on top of the stack) from the second (the
1118** next on stack)
1119** and push the result back onto the stack. If either element
1120** is a string then it is converted to a double using the atof()
1121** function before the division. Division by zero returns NULL.
1122** If either operand is NULL, the result is NULL.
1123*/
1124/* Opcode: Remainder * * *
1125**
1126** Pop the top two elements from the stack, divide the
1127** first (what was on top of the stack) from the second (the
1128** next on stack)
1129** and push the remainder after division onto the stack. If either element
1130** is a string then it is converted to a double using the atof()
1131** function before the division. Division by zero returns NULL.
1132** If either operand is NULL, the result is NULL.
1133*/
1134case OP_Add: /* same as TK_PLUS, no-push */
1135case OP_Subtract: /* same as TK_MINUS, no-push */
1136case OP_Multiply: /* same as TK_STAR, no-push */
1137case OP_Divide: /* same as TK_SLASH, no-push */
1138case OP_Remainder: { /* same as TK_REM, no-push */
1139 Mem *pNos = &pTos[-1];
1140 int flags;
1141 assert( pNos>=p->aStack );
1142 flags = pTos->flags | pNos->flags;
1143 if( (flags & MEM_Null)!=0 ){
1144 Release(pTos);
1145 pTos--;
1146 Release(pTos);
1147 pTos->flags = MEM_Null;
1148 }else if( (pTos->flags & pNos->flags & MEM_Int)==MEM_Int ){
1149 i64 a, b;
1150 a = pTos->u.i;
1151 b = pNos->u.i;
1152 switch( pOp->opcode ){
1153 case OP_Add: b += a; break;
1154 case OP_Subtract: b -= a; break;
1155 case OP_Multiply: b *= a; break;
1156 case OP_Divide: {
1157 if( a==0 ) goto divide_by_zero;
1158 /* Dividing the largest possible negative 64-bit integer (1<<63) by
1159 ** -1 returns an integer to large to store in a 64-bit data-type. On
1160 ** some architectures, the value overflows to (1<<63). On others,
1161 ** a SIGFPE is issued. The following statement normalizes this
1162 ** behaviour so that all architectures behave as if integer
1163 ** overflow occured.
1164 */
1165 if( a==-1 && b==(((i64)1)<<63) ) a = 1;
1166 b /= a;
1167 break;
1168 }
1169 default: {
1170 if( a==0 ) goto divide_by_zero;
1171 if( a==-1 ) a = 1;
1172 b %= a;
1173 break;
1174 }
1175 }
1176 Release(pTos);
1177 pTos--;
1178 Release(pTos);
1179 pTos->u.i = b;
1180 pTos->flags = MEM_Int;
1181 }else{
1182 double a, b;
1183 a = sqlite3VdbeRealValue(pTos);
1184 b = sqlite3VdbeRealValue(pNos);
1185 switch( pOp->opcode ){
1186 case OP_Add: b += a; break;
1187 case OP_Subtract: b -= a; break;
1188 case OP_Multiply: b *= a; break;
1189 case OP_Divide: {
1190 if( a==0.0 ) goto divide_by_zero;
1191 b /= a;
1192 break;
1193 }
1194 default: {
1195 i64 ia = (i64)a;
1196 i64 ib = (i64)b;
1197 if( ia==0 ) goto divide_by_zero;
1198 if( ia==-1 ) ia = 1;
1199 b = ib % ia;
1200 break;
1201 }
1202 }
1203 if( sqlite3_isnan(b) ){
1204 goto divide_by_zero;
1205 }
1206 Release(pTos);
1207 pTos--;
1208 Release(pTos);
1209 pTos->r = b;
1210 pTos->flags = MEM_Real;
1211 if( (flags & MEM_Real)==0 ){
1212 sqlite3VdbeIntegerAffinity(pTos);
1213 }
1214 }
1215 break;
1216
1217divide_by_zero:
1218 Release(pTos);
1219 pTos--;
1220 Release(pTos);
1221 pTos->flags = MEM_Null;
1222 break;
1223}
1224
1225/* Opcode: CollSeq * * P3
1226**
1227** P3 is a pointer to a CollSeq struct. If the next call to a user function
1228** or aggregate calls sqlite3GetFuncCollSeq(), this collation sequence will
1229** be returned. This is used by the built-in min(), max() and nullif()
1230** functions.
1231**
1232** The interface used by the implementation of the aforementioned functions
1233** to retrieve the collation sequence set by this opcode is not available
1234** publicly, only to user functions defined in func.c.
1235*/
1236case OP_CollSeq: { /* no-push */
1237 assert( pOp->p3type==P3_COLLSEQ );
1238 break;
1239}
1240
1241/* Opcode: Function P1 P2 P3
1242**
1243** Invoke a user function (P3 is a pointer to a Function structure that
1244** defines the function) with P2 arguments taken from the stack. Pop all
1245** arguments from the stack and push back the result.
1246**
1247** P1 is a 32-bit bitmask indicating whether or not each argument to the
1248** function was determined to be constant at compile time. If the first
1249** argument was constant then bit 0 of P1 is set. This is used to determine
1250** whether meta data associated with a user function argument using the
1251** sqlite3_set_auxdata() API may be safely retained until the next
1252** invocation of this opcode.
1253**
1254** See also: AggStep and AggFinal
1255*/
1256case OP_Function: {
1257 int i;
1258 Mem *pArg;
1259 sqlite3_context ctx;
1260 sqlite3_value **apVal;
1261 int n = pOp->p2;
1262
1263 apVal = p->apArg;
1264 assert( apVal || n==0 );
1265
1266 pArg = &pTos[1-n];
1267 for(i=0; i<n; i++, pArg++){
1268 apVal[i] = pArg;
1269 storeTypeInfo(pArg, encoding);
1270 }
1271
1272 assert( pOp->p3type==P3_FUNCDEF || pOp->p3type==P3_VDBEFUNC );
1273 if( pOp->p3type==P3_FUNCDEF ){
1274 ctx.pFunc = (FuncDef*)pOp->p3;
1275 ctx.pVdbeFunc = 0;
1276 }else{
1277 ctx.pVdbeFunc = (VdbeFunc*)pOp->p3;
1278 ctx.pFunc = ctx.pVdbeFunc->pFunc;
1279 }
1280
1281 ctx.s.flags = MEM_Null;
1282 ctx.s.z = 0;
1283 ctx.s.xDel = 0;
1284 ctx.s.db = db;
1285 ctx.isError = 0;
1286 if( ctx.pFunc->needCollSeq ){
1287 assert( pOp>p->aOp );
1288 assert( pOp[-1].p3type==P3_COLLSEQ );
1289 assert( pOp[-1].opcode==OP_CollSeq );
1290 ctx.pColl = (CollSeq *)pOp[-1].p3;
1291 }
1292 if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
1293 (*ctx.pFunc->xFunc)(&ctx, n, apVal);
1294 if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
1295 if( db->mallocFailed ){
1296 /* Even though a malloc() has failed, the implementation of the
1297 ** user function may have called an sqlite3_result_XXX() function
1298 ** to return a value. The following call releases any resources
1299 ** associated with such a value.
1300 **
1301 ** Note: Maybe MemRelease() should be called if sqlite3SafetyOn()
1302 ** fails also (the if(...) statement above). But if people are
1303 ** misusing sqlite, they have bigger problems than a leaked value.
1304 */
1305 sqlite3VdbeMemRelease(&ctx.s);
1306 goto no_mem;
1307 }
1308 popStack(&pTos, n);
1309
1310 /* If any auxilary data functions have been called by this user function,
1311 ** immediately call the destructor for any non-static values.
1312 */
1313 if( ctx.pVdbeFunc ){
1314 sqlite3VdbeDeleteAuxData(ctx.pVdbeFunc, pOp->p1);
1315 pOp->p3 = (char *)ctx.pVdbeFunc;
1316 pOp->p3type = P3_VDBEFUNC;
1317 }
1318
1319 /* If the function returned an error, throw an exception */
1320 if( ctx.isError ){
1321 sqlite3SetString(&p->zErrMsg, sqlite3_value_text(&ctx.s), (char*)0);
1322 rc = SQLITE_ERROR;
1323 }
1324
1325 /* Copy the result of the function to the top of the stack */
1326 sqlite3VdbeChangeEncoding(&ctx.s, encoding);
1327 pTos++;
1328 pTos->flags = 0;
1329 sqlite3VdbeMemMove(pTos, &ctx.s);
1330 if( sqlite3VdbeMemTooBig(pTos) ){
1331 goto too_big;
1332 }
1333 break;
1334}
1335
1336/* Opcode: BitAnd * * *
1337**
1338** Pop the top two elements from the stack. Convert both elements
1339** to integers. Push back onto the stack the bit-wise AND of the
1340** two elements.
1341** If either operand is NULL, the result is NULL.
1342*/
1343/* Opcode: BitOr * * *
1344**
1345** Pop the top two elements from the stack. Convert both elements
1346** to integers. Push back onto the stack the bit-wise OR of the
1347** two elements.
1348** If either operand is NULL, the result is NULL.
1349*/
1350/* Opcode: ShiftLeft * * *
1351**
1352** Pop the top two elements from the stack. Convert both elements
1353** to integers. Push back onto the stack the second element shifted
1354** left by N bits where N is the top element on the stack.
1355** If either operand is NULL, the result is NULL.
1356*/
1357/* Opcode: ShiftRight * * *
1358**
1359** Pop the top two elements from the stack. Convert both elements
1360** to integers. Push back onto the stack the second element shifted
1361** right by N bits where N is the top element on the stack.
1362** If either operand is NULL, the result is NULL.
1363*/
1364case OP_BitAnd: /* same as TK_BITAND, no-push */
1365case OP_BitOr: /* same as TK_BITOR, no-push */
1366case OP_ShiftLeft: /* same as TK_LSHIFT, no-push */
1367case OP_ShiftRight: { /* same as TK_RSHIFT, no-push */
1368 Mem *pNos = &pTos[-1];
1369 i64 a, b;
1370
1371 assert( pNos>=p->aStack );
1372 if( (pTos->flags | pNos->flags) & MEM_Null ){
1373 popStack(&pTos, 2);
1374 pTos++;
1375 pTos->flags = MEM_Null;
1376 break;
1377 }
1378 a = sqlite3VdbeIntValue(pNos);
1379 b = sqlite3VdbeIntValue(pTos);
1380 switch( pOp->opcode ){
1381 case OP_BitAnd: a &= b; break;
1382 case OP_BitOr: a |= b; break;
1383 case OP_ShiftLeft: a <<= b; break;
1384 case OP_ShiftRight: a >>= b; break;
1385 default: /* CANT HAPPEN */ break;
1386 }
1387 Release(pTos);
1388 pTos--;
1389 Release(pTos);
1390 pTos->u.i = a;
1391 pTos->flags = MEM_Int;
1392 break;
1393}
1394
1395/* Opcode: AddImm P1 * *
1396**
1397** Add the value P1 to whatever is on top of the stack. The result
1398** is always an integer.
1399**
1400** To force the top of the stack to be an integer, just add 0.
1401*/
1402case OP_AddImm: { /* no-push */
1403 assert( pTos>=p->aStack );
1404 sqlite3VdbeMemIntegerify(pTos);
1405 pTos->u.i += pOp->p1;
1406 break;
1407}
1408
1409/* Opcode: ForceInt P1 P2 *
1410**
1411** Convert the top of the stack into an integer. If the current top of
1412** the stack is not numeric (meaning that is is a NULL or a string that
1413** does not look like an integer or floating point number) then pop the
1414** stack and jump to P2. If the top of the stack is numeric then
1415** convert it into the least integer that is greater than or equal to its
1416** current value if P1==0, or to the least integer that is strictly
1417** greater than its current value if P1==1.
1418*/
1419case OP_ForceInt: { /* no-push */
1420 i64 v;
1421 assert( pTos>=p->aStack );
1422 applyAffinity(pTos, SQLITE_AFF_NUMERIC, encoding);
1423 if( (pTos->flags & (MEM_Int|MEM_Real))==0 ){
1424 Release(pTos);
1425 pTos--;
1426 pc = pOp->p2 - 1;
1427 break;
1428 }
1429 if( pTos->flags & MEM_Int ){
1430 v = pTos->u.i + (pOp->p1!=0);
1431 }else{
1432 /* FIX ME: should this not be assert( pTos->flags & MEM_Real ) ??? */
1433 sqlite3VdbeMemRealify(pTos);
1434 v = (int)pTos->r;
1435 if( pTos->r>(double)v ) v++;
1436 if( pOp->p1 && pTos->r==(double)v ) v++;
1437 }
1438 Release(pTos);
1439 pTos->u.i = v;
1440 pTos->flags = MEM_Int;
1441 break;
1442}
1443
1444/* Opcode: MustBeInt P1 P2 *
1445**
1446** Force the top of the stack to be an integer. If the top of the
1447** stack is not an integer and cannot be converted into an integer
1448** with out data loss, then jump immediately to P2, or if P2==0
1449** raise an SQLITE_MISMATCH exception.
1450**
1451** If the top of the stack is not an integer and P2 is not zero and
1452** P1 is 1, then the stack is popped. In all other cases, the depth
1453** of the stack is unchanged.
1454*/
1455case OP_MustBeInt: { /* no-push */
1456 assert( pTos>=p->aStack );
1457 applyAffinity(pTos, SQLITE_AFF_NUMERIC, encoding);
1458 if( (pTos->flags & MEM_Int)==0 ){
1459 if( pOp->p2==0 ){
1460 rc = SQLITE_MISMATCH;
1461 goto abort_due_to_error;
1462 }else{
1463 if( pOp->p1 ) popStack(&pTos, 1);
1464 pc = pOp->p2 - 1;
1465 }
1466 }else{
1467 Release(pTos);
1468 pTos->flags = MEM_Int;
1469 }
1470 break;
1471}
1472
1473/* Opcode: RealAffinity * * *
1474**
1475** If the top of the stack is an integer, convert it to a real value.
1476**
1477** This opcode is used when extracting information from a column that
1478** has REAL affinity. Such column values may still be stored as
1479** integers, for space efficiency, but after extraction we want them
1480** to have only a real value.
1481*/
1482case OP_RealAffinity: { /* no-push */
1483 assert( pTos>=p->aStack );
1484 if( pTos->flags & MEM_Int ){
1485 sqlite3VdbeMemRealify(pTos);
1486 }
1487 break;
1488}
1489
1490#ifndef SQLITE_OMIT_CAST
1491/* Opcode: ToText * * *
1492**
1493** Force the value on the top of the stack to be text.
1494** If the value is numeric, convert it to a string using the
1495** equivalent of printf(). Blob values are unchanged and
1496** are afterwards simply interpreted as text.
1497**
1498** A NULL value is not changed by this routine. It remains NULL.
1499*/
1500case OP_ToText: { /* same as TK_TO_TEXT, no-push */
1501 assert( pTos>=p->aStack );
1502 if( pTos->flags & MEM_Null ) break;
1503 assert( MEM_Str==(MEM_Blob>>3) );
1504 pTos->flags |= (pTos->flags&MEM_Blob)>>3;
1505 applyAffinity(pTos, SQLITE_AFF_TEXT, encoding);
1506 rc = ExpandBlob(pTos);
1507 assert( pTos->flags & MEM_Str );
1508 pTos->flags &= ~(MEM_Int|MEM_Real|MEM_Blob);
1509 break;
1510}
1511
1512/* Opcode: ToBlob * * *
1513**
1514** Force the value on the top of the stack to be a BLOB.
1515** If the value is numeric, convert it to a string first.
1516** Strings are simply reinterpreted as blobs with no change
1517** to the underlying data.
1518**
1519** A NULL value is not changed by this routine. It remains NULL.
1520*/
1521case OP_ToBlob: { /* same as TK_TO_BLOB, no-push */
1522 assert( pTos>=p->aStack );
1523 if( pTos->flags & MEM_Null ) break;
1524 if( (pTos->flags & MEM_Blob)==0 ){
1525 applyAffinity(pTos, SQLITE_AFF_TEXT, encoding);
1526 assert( pTos->flags & MEM_Str );
1527 pTos->flags |= MEM_Blob;
1528 }
1529 pTos->flags &= ~(MEM_Int|MEM_Real|MEM_Str);
1530 break;
1531}
1532
1533/* Opcode: ToNumeric * * *
1534**
1535** Force the value on the top of the stack to be numeric (either an
1536** integer or a floating-point number.)
1537** If the value is text or blob, try to convert it to an using the
1538** equivalent of atoi() or atof() and store 0 if no such conversion
1539** is possible.
1540**
1541** A NULL value is not changed by this routine. It remains NULL.
1542*/
1543case OP_ToNumeric: { /* same as TK_TO_NUMERIC, no-push */
1544 assert( pTos>=p->aStack );
1545 if( (pTos->flags & (MEM_Null|MEM_Int|MEM_Real))==0 ){
1546 sqlite3VdbeMemNumerify(pTos);
1547 }
1548 break;
1549}
1550#endif /* SQLITE_OMIT_CAST */
1551
1552/* Opcode: ToInt * * *
1553**
1554** Force the value on the top of the stack to be an integer. If
1555** The value is currently a real number, drop its fractional part.
1556** If the value is text or blob, try to convert it to an integer using the
1557** equivalent of atoi() and store 0 if no such conversion is possible.
1558**
1559** A NULL value is not changed by this routine. It remains NULL.
1560*/
1561case OP_ToInt: { /* same as TK_TO_INT, no-push */
1562 assert( pTos>=p->aStack );
1563 if( (pTos->flags & MEM_Null)==0 ){
1564 sqlite3VdbeMemIntegerify(pTos);
1565 }
1566 break;
1567}
1568
1569#ifndef SQLITE_OMIT_CAST
1570/* Opcode: ToReal * * *
1571**
1572** Force the value on the top of the stack to be a floating point number.
1573** If The value is currently an integer, convert it.
1574** If the value is text or blob, try to convert it to an integer using the
1575** equivalent of atoi() and store 0 if no such conversion is possible.
1576**
1577** A NULL value is not changed by this routine. It remains NULL.
1578*/
1579case OP_ToReal: { /* same as TK_TO_REAL, no-push */
1580 assert( pTos>=p->aStack );
1581 if( (pTos->flags & MEM_Null)==0 ){
1582 sqlite3VdbeMemRealify(pTos);
1583 }
1584 break;
1585}
1586#endif /* SQLITE_OMIT_CAST */
1587
1588/* Opcode: Eq P1 P2 P3
1589**
1590** Pop the top two elements from the stack. If they are equal, then
1591** jump to instruction P2. Otherwise, continue to the next instruction.
1592**
1593** If the 0x100 bit of P1 is true and either operand is NULL then take the
1594** jump. If the 0x100 bit of P1 is clear then fall thru if either operand
1595** is NULL.
1596**
1597** If the 0x200 bit of P1 is set and either operand is NULL then
1598** both operands are converted to integers prior to comparison.
1599** NULL operands are converted to zero and non-NULL operands are
1600** converted to 1. Thus, for example, with 0x200 set, NULL==NULL is true
1601** whereas it would normally be NULL. Similarly, NULL==123 is false when
1602** 0x200 is set but is NULL when the 0x200 bit of P1 is clear.
1603**
1604** The least significant byte of P1 (mask 0xff) must be an affinity character -
1605** SQLITE_AFF_TEXT, SQLITE_AFF_INTEGER, and so forth. An attempt is made
1606** to coerce both values
1607** according to the affinity before the comparison is made. If the byte is
1608** 0x00, then numeric affinity is used.
1609**
1610** Once any conversions have taken place, and neither value is NULL,
1611** the values are compared. If both values are blobs, or both are text,
1612** then memcmp() is used to determine the results of the comparison. If
1613** both values are numeric, then a numeric comparison is used. If the
1614** two values are of different types, then they are inequal.
1615**
1616** If P2 is zero, do not jump. Instead, push an integer 1 onto the
1617** stack if the jump would have been taken, or a 0 if not. Push a
1618** NULL if either operand was NULL.
1619**
1620** If P3 is not NULL it is a pointer to a collating sequence (a CollSeq
1621** structure) that defines how to compare text.
1622*/
1623/* Opcode: Ne P1 P2 P3
1624**
1625** This works just like the Eq opcode except that the jump is taken if
1626** the operands from the stack are not equal. See the Eq opcode for
1627** additional information.
1628*/
1629/* Opcode: Lt P1 P2 P3
1630**
1631** This works just like the Eq opcode except that the jump is taken if
1632** the 2nd element down on the stack is less than the top of the stack.
1633** See the Eq opcode for additional information.
1634*/
1635/* Opcode: Le P1 P2 P3
1636**
1637** This works just like the Eq opcode except that the jump is taken if
1638** the 2nd element down on the stack is less than or equal to the
1639** top of the stack. See the Eq opcode for additional information.
1640*/
1641/* Opcode: Gt P1 P2 P3
1642**
1643** This works just like the Eq opcode except that the jump is taken if
1644** the 2nd element down on the stack is greater than the top of the stack.
1645** See the Eq opcode for additional information.
1646*/
1647/* Opcode: Ge P1 P2 P3
1648**
1649** This works just like the Eq opcode except that the jump is taken if
1650** the 2nd element down on the stack is greater than or equal to the
1651** top of the stack. See the Eq opcode for additional information.
1652*/
1653case OP_Eq: /* same as TK_EQ, no-push */
1654case OP_Ne: /* same as TK_NE, no-push */
1655case OP_Lt: /* same as TK_LT, no-push */
1656case OP_Le: /* same as TK_LE, no-push */
1657case OP_Gt: /* same as TK_GT, no-push */
1658case OP_Ge: { /* same as TK_GE, no-push */
1659 Mem *pNos;
1660 int flags;
1661 int res;
1662 char affinity;
1663
1664 pNos = &pTos[-1];
1665 flags = pTos->flags|pNos->flags;
1666
1667 /* If either value is a NULL P2 is not zero, take the jump if the least
1668 ** significant byte of P1 is true. If P2 is zero, then push a NULL onto
1669 ** the stack.
1670 */
1671 if( flags&MEM_Null ){
1672 if( (pOp->p1 & 0x200)!=0 ){
1673 /* The 0x200 bit of P1 means, roughly "do not treat NULL as the
1674 ** magic SQL value it normally is - treat it as if it were another
1675 ** integer".
1676 **
1677 ** With 0x200 set, if either operand is NULL then both operands
1678 ** are converted to integers prior to being passed down into the
1679 ** normal comparison logic below. NULL operands are converted to
1680 ** zero and non-NULL operands are converted to 1. Thus, for example,
1681 ** with 0x200 set, NULL==NULL is true whereas it would normally
1682 ** be NULL. Similarly, NULL!=123 is true.
1683 */
1684 sqlite3VdbeMemSetInt64(pTos, (pTos->flags & MEM_Null)==0);
1685 sqlite3VdbeMemSetInt64(pNos, (pNos->flags & MEM_Null)==0);
1686 }else{
1687 /* If the 0x200 bit of P1 is clear and either operand is NULL then
1688 ** the result is always NULL. The jump is taken if the 0x100 bit
1689 ** of P1 is set.
1690 */
1691 popStack(&pTos, 2);
1692 if( pOp->p2 ){
1693 if( pOp->p1 & 0x100 ){
1694 pc = pOp->p2-1;
1695 }
1696 }else{
1697 pTos++;
1698 pTos->flags = MEM_Null;
1699 }
1700 break;
1701 }
1702 }
1703
1704 affinity = pOp->p1 & 0xFF;
1705 if( affinity ){
1706 applyAffinity(pNos, affinity, encoding);
1707 applyAffinity(pTos, affinity, encoding);
1708 }
1709
1710 assert( pOp->p3type==P3_COLLSEQ || pOp->p3==0 );
1711 ExpandBlob(pNos);
1712 ExpandBlob(pTos);
1713 res = sqlite3MemCompare(pNos, pTos, (CollSeq*)pOp->p3);
1714 switch( pOp->opcode ){
1715 case OP_Eq: res = res==0; break;
1716 case OP_Ne: res = res!=0; break;
1717 case OP_Lt: res = res<0; break;
1718 case OP_Le: res = res<=0; break;
1719 case OP_Gt: res = res>0; break;
1720 default: res = res>=0; break;
1721 }
1722
1723 popStack(&pTos, 2);
1724 if( pOp->p2 ){
1725 if( res ){
1726 pc = pOp->p2-1;
1727 }
1728 }else{
1729 pTos++;
1730 pTos->flags = MEM_Int;
1731 pTos->u.i = res;
1732 }
1733 break;
1734}
1735
1736/* Opcode: And * * *
1737**
1738** Pop two values off the stack. Take the logical AND of the
1739** two values and push the resulting boolean value back onto the
1740** stack.
1741*/
1742/* Opcode: Or * * *
1743**
1744** Pop two values off the stack. Take the logical OR of the
1745** two values and push the resulting boolean value back onto the
1746** stack.
1747*/
1748case OP_And: /* same as TK_AND, no-push */
1749case OP_Or: { /* same as TK_OR, no-push */
1750 Mem *pNos = &pTos[-1];
1751 int v1, v2; /* 0==TRUE, 1==FALSE, 2==UNKNOWN or NULL */
1752
1753 assert( pNos>=p->aStack );
1754 if( pTos->flags & MEM_Null ){
1755 v1 = 2;
1756 }else{
1757 sqlite3VdbeMemIntegerify(pTos);
1758 v1 = pTos->u.i==0;
1759 }
1760 if( pNos->flags & MEM_Null ){
1761 v2 = 2;
1762 }else{
1763 sqlite3VdbeMemIntegerify(pNos);
1764 v2 = pNos->u.i==0;
1765 }
1766 if( pOp->opcode==OP_And ){
1767 static const unsigned char and_logic[] = { 0, 1, 2, 1, 1, 1, 2, 1, 2 };
1768 v1 = and_logic[v1*3+v2];
1769 }else{
1770 static const unsigned char or_logic[] = { 0, 0, 0, 0, 1, 2, 0, 2, 2 };
1771 v1 = or_logic[v1*3+v2];
1772 }
1773 popStack(&pTos, 2);
1774 pTos++;
1775 if( v1==2 ){
1776 pTos->flags = MEM_Null;
1777 }else{
1778 pTos->u.i = v1==0;
1779 pTos->flags = MEM_Int;
1780 }
1781 break;
1782}
1783
1784/* Opcode: Negative * * *
1785**
1786** Treat the top of the stack as a numeric quantity. Replace it
1787** with its additive inverse. If the top of the stack is NULL
1788** its value is unchanged.
1789*/
1790/* Opcode: AbsValue * * *
1791**
1792** Treat the top of the stack as a numeric quantity. Replace it
1793** with its absolute value. If the top of the stack is NULL
1794** its value is unchanged.
1795*/
1796case OP_Negative: /* same as TK_UMINUS, no-push */
1797case OP_AbsValue: {
1798 assert( pTos>=p->aStack );
1799 if( (pTos->flags & (MEM_Real|MEM_Int|MEM_Null))==0 ){
1800 sqlite3VdbeMemNumerify(pTos);
1801 }
1802 if( pTos->flags & MEM_Real ){
1803 Release(pTos);
1804 if( pOp->opcode==OP_Negative || pTos->r<0.0 ){
1805 pTos->r = -pTos->r;
1806 }
1807 pTos->flags = MEM_Real;
1808 }else if( pTos->flags & MEM_Int ){
1809 Release(pTos);
1810 if( pOp->opcode==OP_Negative || pTos->u.i<0 ){
1811 pTos->u.i = -pTos->u.i;
1812 }
1813 pTos->flags = MEM_Int;
1814 }
1815 break;
1816}
1817
1818/* Opcode: Not * * *
1819**
1820** Interpret the top of the stack as a boolean value. Replace it
1821** with its complement. If the top of the stack is NULL its value
1822** is unchanged.
1823*/
1824case OP_Not: { /* same as TK_NOT, no-push */
1825 assert( pTos>=p->aStack );
1826 if( pTos->flags & MEM_Null ) break; /* Do nothing to NULLs */
1827 sqlite3VdbeMemIntegerify(pTos);
1828 assert( (pTos->flags & MEM_Dyn)==0 );
1829 pTos->u.i = !pTos->u.i;
1830 pTos->flags = MEM_Int;
1831 break;
1832}
1833
1834/* Opcode: BitNot * * *
1835**
1836** Interpret the top of the stack as an value. Replace it
1837** with its ones-complement. If the top of the stack is NULL its
1838** value is unchanged.
1839*/
1840case OP_BitNot: { /* same as TK_BITNOT, no-push */
1841 assert( pTos>=p->aStack );
1842 if( pTos->flags & MEM_Null ) break; /* Do nothing to NULLs */
1843 sqlite3VdbeMemIntegerify(pTos);
1844 assert( (pTos->flags & MEM_Dyn)==0 );
1845 pTos->u.i = ~pTos->u.i;
1846 pTos->flags = MEM_Int;
1847 break;
1848}
1849
1850/* Opcode: Noop * * *
1851**
1852** Do nothing. This instruction is often useful as a jump
1853** destination.
1854*/
1855/*
1856** The magic Explain opcode are only inserted when explain==2 (which
1857** is to say when the EXPLAIN QUERY PLAN syntax is used.)
1858** This opcode records information from the optimizer. It is the
1859** the same as a no-op. This opcodesnever appears in a real VM program.
1860*/
1861case OP_Explain:
1862case OP_Noop: { /* no-push */
1863 break;
1864}
1865
1866/* Opcode: If P1 P2 *
1867**
1868** Pop a single boolean from the stack. If the boolean popped is
1869** true, then jump to p2. Otherwise continue to the next instruction.
1870** An integer is false if zero and true otherwise. A string is
1871** false if it has zero length and true otherwise.
1872**
1873** If the value popped of the stack is NULL, then take the jump if P1
1874** is true and fall through if P1 is false.
1875*/
1876/* Opcode: IfNot P1 P2 *
1877**
1878** Pop a single boolean from the stack. If the boolean popped is
1879** false, then jump to p2. Otherwise continue to the next instruction.
1880** An integer is false if zero and true otherwise. A string is
1881** false if it has zero length and true otherwise.
1882**
1883** If the value popped of the stack is NULL, then take the jump if P1
1884** is true and fall through if P1 is false.
1885*/
1886case OP_If: /* no-push */
1887case OP_IfNot: { /* no-push */
1888 int c;
1889 assert( pTos>=p->aStack );
1890 if( pTos->flags & MEM_Null ){
1891 c = pOp->p1;
1892 }else{
1893#ifdef SQLITE_OMIT_FLOATING_POINT
1894 c = sqlite3VdbeIntValue(pTos);
1895#else
1896 c = sqlite3VdbeRealValue(pTos)!=0.0;
1897#endif
1898 if( pOp->opcode==OP_IfNot ) c = !c;
1899 }
1900 Release(pTos);
1901 pTos--;
1902 if( c ) pc = pOp->p2-1;
1903 break;
1904}
1905
1906/* Opcode: IsNull P1 P2 *
1907**
1908** Check the top of the stack and jump to P2 if the top of the stack
1909** is NULL. If P1 is positive, then pop P1 elements from the stack
1910** regardless of whether or not the jump is taken. If P1 is negative,
1911** pop -P1 elements from the stack only if the jump is taken and leave
1912** the stack unchanged if the jump is not taken.
1913*/
1914case OP_IsNull: { /* same as TK_ISNULL, no-push */
1915 if( pTos->flags & MEM_Null ){
1916 pc = pOp->p2-1;
1917 if( pOp->p1<0 ){
1918 popStack(&pTos, -pOp->p1);
1919 }
1920 }
1921 if( pOp->p1>0 ){
1922 popStack(&pTos, pOp->p1);
1923 }
1924 break;
1925}
1926
1927/* Opcode: NotNull P1 P2 *
1928**
1929** Jump to P2 if the top abs(P1) values on the stack are all not NULL.
1930** Regardless of whether or not the jump is taken, pop the stack
1931** P1 times if P1 is greater than zero. But if P1 is negative,
1932** leave the stack unchanged.
1933*/
1934case OP_NotNull: { /* same as TK_NOTNULL, no-push */
1935 int i, cnt;
1936 cnt = pOp->p1;
1937 if( cnt<0 ) cnt = -cnt;
1938 assert( &pTos[1-cnt] >= p->aStack );
1939 for(i=0; i<cnt && (pTos[1+i-cnt].flags & MEM_Null)==0; i++){}
1940 if( i>=cnt ) pc = pOp->p2-1;
1941 if( pOp->p1>0 ) popStack(&pTos, cnt);
1942 break;
1943}
1944
1945/* Opcode: SetNumColumns P1 P2 *
1946**
1947** Before the OP_Column opcode can be executed on a cursor, this
1948** opcode must be called to set the number of fields in the table.
1949**
1950** This opcode sets the number of columns for cursor P1 to P2.
1951**
1952** If OP_KeyAsData is to be applied to cursor P1, it must be executed
1953** before this op-code.
1954*/
1955case OP_SetNumColumns: { /* no-push */
1956 Cursor *pC;
1957 assert( (pOp->p1)<p->nCursor );
1958 assert( p->apCsr[pOp->p1]!=0 );
1959 pC = p->apCsr[pOp->p1];
1960 pC->nField = pOp->p2;
1961 break;
1962}
1963
1964/* Opcode: Column P1 P2 P3
1965**
1966** Interpret the data that cursor P1 points to as a structure built using
1967** the MakeRecord instruction. (See the MakeRecord opcode for additional
1968** information about the format of the data.) Push onto the stack the value
1969** of the P2-th column contained in the data. If there are less that (P2+1)
1970** values in the record, push a NULL onto the stack.
1971**
1972** If the KeyAsData opcode has previously executed on this cursor, then the
1973** field might be extracted from the key rather than the data.
1974**
1975** If the column contains fewer than P2 fields, then push a NULL. Or
1976** if P3 is of type P3_MEM, then push the P3 value. The P3 value will
1977** be default value for a column that has been added using the ALTER TABLE
1978** ADD COLUMN command. If P3 is an ordinary string, just push a NULL.
1979** When P3 is a string it is really just a comment describing the value
1980** to be pushed, not a default value.
1981*/
1982case OP_Column: {
1983 u32 payloadSize; /* Number of bytes in the record */
1984 int p1 = pOp->p1; /* P1 value of the opcode */
1985 int p2 = pOp->p2; /* column number to retrieve */
1986 Cursor *pC = 0; /* The VDBE cursor */
1987 char *zRec; /* Pointer to complete record-data */
1988 BtCursor *pCrsr; /* The BTree cursor */
1989 u32 *aType; /* aType[i] holds the numeric type of the i-th column */
1990 u32 *aOffset; /* aOffset[i] is offset to start of data for i-th column */
1991 u32 nField; /* number of fields in the record */
1992 int len; /* The length of the serialized data for the column */
1993 int i; /* Loop counter */
1994 char *zData; /* Part of the record being decoded */
1995 Mem sMem; /* For storing the record being decoded */
1996
1997 sMem.flags = 0;
1998 assert( p1<p->nCursor );
1999 pTos++;
2000 pTos->flags = MEM_Null;
2001
2002 /* This block sets the variable payloadSize to be the total number of
2003 ** bytes in the record.
2004 **
2005 ** zRec is set to be the complete text of the record if it is available.
2006 ** The complete record text is always available for pseudo-tables
2007 ** If the record is stored in a cursor, the complete record text
2008 ** might be available in the pC->aRow cache. Or it might not be.
2009 ** If the data is unavailable, zRec is set to NULL.
2010 **
2011 ** We also compute the number of columns in the record. For cursors,
2012 ** the number of columns is stored in the Cursor.nField element. For
2013 ** records on the stack, the next entry down on the stack is an integer
2014 ** which is the number of records.
2015 */
2016 pC = p->apCsr[p1];
2017#ifndef SQLITE_OMIT_VIRTUALTABLE
2018 assert( pC->pVtabCursor==0 );
2019#endif
2020 assert( pC!=0 );
2021 if( pC->pCursor!=0 ){
2022 /* The record is stored in a B-Tree */
2023 rc = sqlite3VdbeCursorMoveto(pC);
2024 if( rc ) goto abort_due_to_error;
2025 zRec = 0;
2026 pCrsr = pC->pCursor;
2027 if( pC->nullRow ){
2028 payloadSize = 0;
2029 }else if( pC->cacheStatus==p->cacheCtr ){
2030 payloadSize = pC->payloadSize;
2031 zRec = (char*)pC->aRow;
2032 }else if( pC->isIndex ){
2033 i64 payloadSize64;
2034 sqlite3BtreeKeySize(pCrsr, &payloadSize64);
2035 payloadSize = payloadSize64;
2036 }else{
2037 sqlite3BtreeDataSize(pCrsr, &payloadSize);
2038 }
2039 nField = pC->nField;
2040 }else if( pC->pseudoTable ){
2041 /* The record is the sole entry of a pseudo-table */
2042 payloadSize = pC->nData;
2043 zRec = pC->pData;
2044 pC->cacheStatus = CACHE_STALE;
2045 assert( payloadSize==0 || zRec!=0 );
2046 nField = pC->nField;
2047 pCrsr = 0;
2048 }else{
2049 zRec = 0;
2050 payloadSize = 0;
2051 pCrsr = 0;
2052 nField = 0;
2053 }
2054
2055 /* If payloadSize is 0, then just push a NULL onto the stack. */
2056 if( payloadSize==0 ){
2057 assert( pTos->flags==MEM_Null );
2058 break;
2059 }
2060 if( payloadSize>SQLITE_MAX_LENGTH ){
2061 goto too_big;
2062 }
2063
2064 assert( p2<nField );
2065
2066 /* Read and parse the table header. Store the results of the parse
2067 ** into the record header cache fields of the cursor.
2068 */
2069 if( pC && pC->cacheStatus==p->cacheCtr ){
2070 aType = pC->aType;
2071 aOffset = pC->aOffset;
2072 }else{
2073 u8 *zIdx; /* Index into header */
2074 u8 *zEndHdr; /* Pointer to first byte after the header */
2075 u32 offset; /* Offset into the data */
2076 int szHdrSz; /* Size of the header size field at start of record */
2077 int avail; /* Number of bytes of available data */
2078
2079 aType = pC->aType;
2080 if( aType==0 ){
2081 pC->aType = aType = sqlite3DbMallocRaw(db, 2*nField*sizeof(aType) );
2082 }
2083 if( aType==0 ){
2084 goto no_mem;
2085 }
2086 pC->aOffset = aOffset = &aType[nField];
2087 pC->payloadSize = payloadSize;
2088 pC->cacheStatus = p->cacheCtr;
2089
2090 /* Figure out how many bytes are in the header */
2091 if( zRec ){
2092 zData = zRec;
2093 }else{
2094 if( pC->isIndex ){
2095 zData = (char*)sqlite3BtreeKeyFetch(pCrsr, &avail);
2096 }else{
2097 zData = (char*)sqlite3BtreeDataFetch(pCrsr, &avail);
2098 }
2099 /* If KeyFetch()/DataFetch() managed to get the entire payload,
2100 ** save the payload in the pC->aRow cache. That will save us from
2101 ** having to make additional calls to fetch the content portion of
2102 ** the record.
2103 */
2104 if( avail>=payloadSize ){
2105 zRec = zData;
2106 pC->aRow = (u8*)zData;
2107 }else{
2108 pC->aRow = 0;
2109 }
2110 }
2111 /* The following assert is true in all cases accept when
2112 ** the database file has been corrupted externally.
2113 ** assert( zRec!=0 || avail>=payloadSize || avail>=9 ); */
2114 szHdrSz = GetVarint((u8*)zData, offset);
2115
2116 /* The KeyFetch() or DataFetch() above are fast and will get the entire
2117 ** record header in most cases. But they will fail to get the complete
2118 ** record header if the record header does not fit on a single page
2119 ** in the B-Tree. When that happens, use sqlite3VdbeMemFromBtree() to
2120 ** acquire the complete header text.
2121 */
2122 if( !zRec && avail<offset ){
2123 rc = sqlite3VdbeMemFromBtree(pCrsr, 0, offset, pC->isIndex, &sMem);
2124 if( rc!=SQLITE_OK ){
2125 goto op_column_out;
2126 }
2127 zData = sMem.z;
2128 }
2129 zEndHdr = (u8 *)&zData[offset];
2130 zIdx = (u8 *)&zData[szHdrSz];
2131
2132 /* Scan the header and use it to fill in the aType[] and aOffset[]
2133 ** arrays. aType[i] will contain the type integer for the i-th
2134 ** column and aOffset[i] will contain the offset from the beginning
2135 ** of the record to the start of the data for the i-th column
2136 */
2137 for(i=0; i<nField; i++){
2138 if( zIdx<zEndHdr ){
2139 aOffset[i] = offset;
2140 zIdx += GetVarint(zIdx, aType[i]);
2141 offset += sqlite3VdbeSerialTypeLen(aType[i]);
2142 }else{
2143 /* If i is less that nField, then there are less fields in this
2144 ** record than SetNumColumns indicated there are columns in the
2145 ** table. Set the offset for any extra columns not present in
2146 ** the record to 0. This tells code below to push a NULL onto the
2147 ** stack instead of deserializing a value from the record.
2148 */
2149 aOffset[i] = 0;
2150 }
2151 }
2152 Release(&sMem);
2153 sMem.flags = MEM_Null;
2154
2155 /* If we have read more header data than was contained in the header,
2156 ** or if the end of the last field appears to be past the end of the
2157 ** record, then we must be dealing with a corrupt database.
2158 */
2159 if( zIdx>zEndHdr || offset>payloadSize ){
2160 rc = SQLITE_CORRUPT_BKPT;
2161 goto op_column_out;
2162 }
2163 }
2164
2165 /* Get the column information. If aOffset[p2] is non-zero, then
2166 ** deserialize the value from the record. If aOffset[p2] is zero,
2167 ** then there are not enough fields in the record to satisfy the
2168 ** request. In this case, set the value NULL or to P3 if P3 is
2169 ** a pointer to a Mem object.
2170 */
2171 if( aOffset[p2] ){
2172 assert( rc==SQLITE_OK );
2173 if( zRec ){
2174 zData = &zRec[aOffset[p2]];
2175 }else{
2176 len = sqlite3VdbeSerialTypeLen(aType[p2]);
2177 rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, pC->isIndex, &sMem);
2178 if( rc!=SQLITE_OK ){
2179 goto op_column_out;
2180 }
2181 zData = sMem.z;
2182 }
2183 sqlite3VdbeSerialGet((u8*)zData, aType[p2], pTos);
2184 pTos->enc = encoding;
2185 }else{
2186 if( pOp->p3type==P3_MEM ){
2187 sqlite3VdbeMemShallowCopy(pTos, (Mem *)(pOp->p3), MEM_Static);
2188 }else{
2189 pTos->flags = MEM_Null;
2190 }
2191 }
2192
2193 /* If we dynamically allocated space to hold the data (in the
2194 ** sqlite3VdbeMemFromBtree() call above) then transfer control of that
2195 ** dynamically allocated space over to the pTos structure.
2196 ** This prevents a memory copy.
2197 */
2198 if( (sMem.flags & MEM_Dyn)!=0 ){
2199 assert( pTos->flags & MEM_Ephem );
2200 assert( pTos->flags & (MEM_Str|MEM_Blob) );
2201 assert( pTos->z==sMem.z );
2202 assert( sMem.flags & MEM_Term );
2203 pTos->flags &= ~MEM_Ephem;
2204 pTos->flags |= MEM_Dyn|MEM_Term;
2205 }
2206
2207 /* pTos->z might be pointing to sMem.zShort[]. Fix that so that we
2208 ** can abandon sMem */
2209 rc = sqlite3VdbeMemMakeWriteable(pTos);
2210
2211op_column_out:
2212 break;
2213}
2214
2215/* Opcode: MakeRecord P1 P2 P3
2216**
2217** Convert the top abs(P1) entries of the stack into a single entry
2218** suitable for use as a data record in a database table or as a key
2219** in an index. The details of the format are irrelavant as long as
2220** the OP_Column opcode can decode the record later and as long as the
2221** sqlite3VdbeRecordCompare function will correctly compare two encoded
2222** records. Refer to source code comments for the details of the record
2223** format.
2224**
2225** The original stack entries are popped from the stack if P1>0 but
2226** remain on the stack if P1<0.
2227**
2228** If P2 is not zero and one or more of the entries are NULL, then jump
2229** to the address given by P2. This feature can be used to skip a
2230** uniqueness test on indices.
2231**
2232** P3 may be a string that is P1 characters long. The nth character of the
2233** string indicates the column affinity that should be used for the nth
2234** field of the index key (i.e. the first character of P3 corresponds to the
2235** lowest element on the stack).
2236**
2237** The mapping from character to affinity is given by the SQLITE_AFF_
2238** macros defined in sqliteInt.h.
2239**
2240** If P3 is NULL then all index fields have the affinity NONE.
2241**
2242** See also OP_MakeIdxRec
2243*/
2244/* Opcode: MakeIdxRec P1 P2 P3
2245**
2246** This opcode works just OP_MakeRecord except that it reads an extra
2247** integer from the stack (thus reading a total of abs(P1+1) entries)
2248** and appends that extra integer to the end of the record as a varint.
2249** This results in an index key.
2250*/
2251case OP_MakeIdxRec:
2252case OP_MakeRecord: {
2253 /* Assuming the record contains N fields, the record format looks
2254 ** like this:
2255 **
2256 ** ------------------------------------------------------------------------
2257 ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 |
2258 ** ------------------------------------------------------------------------
2259 **
2260 ** Data(0) is taken from the lowest element of the stack and data(N-1) is
2261 ** the top of the stack.
2262 **
2263 ** Each type field is a varint representing the serial type of the
2264 ** corresponding data element (see sqlite3VdbeSerialType()). The
2265 ** hdr-size field is also a varint which is the offset from the beginning
2266 ** of the record to data0.
2267 */
2268 u8 *zNewRecord; /* A buffer to hold the data for the new record */
2269 Mem *pRec; /* The new record */
2270 Mem *pRowid = 0; /* Rowid appended to the new record */
2271 u64 nData = 0; /* Number of bytes of data space */
2272 int nHdr = 0; /* Number of bytes of header space */
2273 u64 nByte = 0; /* Data space required for this record */
2274 int nZero = 0; /* Number of zero bytes at the end of the record */
2275 int nVarint; /* Number of bytes in a varint */
2276 u32 serial_type; /* Type field */
2277 int containsNull = 0; /* True if any of the data fields are NULL */
2278 Mem *pData0; /* Bottom of the stack */
2279 int leaveOnStack; /* If true, leave the entries on the stack */
2280 int nField; /* Number of fields in the record */
2281 int jumpIfNull; /* Jump here if non-zero and any entries are NULL. */
2282 int addRowid; /* True to append a rowid column at the end */
2283 char *zAffinity; /* The affinity string for the record */
2284 int file_format; /* File format to use for encoding */
2285 int i; /* Space used in zNewRecord[] */
2286 char zTemp[NBFS]; /* Space to hold small records */
2287
2288 leaveOnStack = ((pOp->p1<0)?1:0);
2289 nField = pOp->p1 * (leaveOnStack?-1:1);
2290 jumpIfNull = pOp->p2;
2291 addRowid = pOp->opcode==OP_MakeIdxRec;
2292 zAffinity = pOp->p3;
2293
2294 pData0 = &pTos[1-nField];
2295 assert( pData0>=p->aStack );
2296 containsNull = 0;
2297 file_format = p->minWriteFileFormat;
2298
2299 /* Loop through the elements that will make up the record to figure
2300 ** out how much space is required for the new record.
2301 */
2302 for(pRec=pData0; pRec<=pTos; pRec++){
2303 int len;
2304 if( zAffinity ){
2305 applyAffinity(pRec, zAffinity[pRec-pData0], encoding);
2306 }
2307 if( pRec->flags&MEM_Null ){
2308 containsNull = 1;
2309 }
2310 if( pRec->flags&MEM_Zero && pRec->n>0 ){
2311 ExpandBlob(pRec);
2312 }
2313 serial_type = sqlite3VdbeSerialType(pRec, file_format);
2314 len = sqlite3VdbeSerialTypeLen(serial_type);
2315 nData += len;
2316 nHdr += sqlite3VarintLen(serial_type);
2317 if( pRec->flags & MEM_Zero ){
2318 /* Only pure zero-filled BLOBs can be input to this Opcode.
2319 ** We do not allow blobs with a prefix and a zero-filled tail. */
2320 nZero += pRec->u.i;
2321 }else if( len ){
2322 nZero = 0;
2323 }
2324 }
2325
2326 /* If we have to append a varint rowid to this record, set pRowid
2327 ** to the value of the rowid and increase nByte by the amount of space
2328 ** required to store it.
2329 */
2330 if( addRowid ){
2331 pRowid = &pTos[0-nField];
2332 assert( pRowid>=p->aStack );
2333 sqlite3VdbeMemIntegerify(pRowid);
2334 serial_type = sqlite3VdbeSerialType(pRowid, 0);
2335 nData += sqlite3VdbeSerialTypeLen(serial_type);
2336 nHdr += sqlite3VarintLen(serial_type);
2337 nZero = 0;
2338 }
2339
2340 /* Add the initial header varint and total the size */
2341 nHdr += nVarint = sqlite3VarintLen(nHdr);
2342 if( nVarint<sqlite3VarintLen(nHdr) ){
2343 nHdr++;
2344 }
2345 nByte = nHdr+nData-nZero;
2346 if( nByte>SQLITE_MAX_LENGTH ){
2347 goto too_big;
2348 }
2349
2350 /* Allocate space for the new record. */
2351 if( nByte>sizeof(zTemp) ){
2352 zNewRecord = sqlite3DbMallocRaw(db, nByte);
2353 if( !zNewRecord ){
2354 goto no_mem;
2355 }
2356 }else{
2357 zNewRecord = (u8*)zTemp;
2358 }
2359
2360 /* Write the record */
2361 i = sqlite3PutVarint(zNewRecord, nHdr);
2362 for(pRec=pData0; pRec<=pTos; pRec++){
2363 serial_type = sqlite3VdbeSerialType(pRec, file_format);
2364 i += sqlite3PutVarint(&zNewRecord[i], serial_type); /* serial type */
2365 }
2366 if( addRowid ){
2367 i += sqlite3PutVarint(&zNewRecord[i], sqlite3VdbeSerialType(pRowid, 0));
2368 }
2369 for(pRec=pData0; pRec<=pTos; pRec++){ /* serial data */
2370 i += sqlite3VdbeSerialPut(&zNewRecord[i], nByte-i, pRec, file_format);
2371 }
2372 if( addRowid ){
2373 i += sqlite3VdbeSerialPut(&zNewRecord[i], nByte-i, pRowid, 0);
2374 }
2375 assert( i==nByte );
2376
2377 /* Pop entries off the stack if required. Push the new record on. */
2378 if( !leaveOnStack ){
2379 popStack(&pTos, nField+addRowid);
2380 }
2381 pTos++;
2382 pTos->n = nByte;
2383 if( nByte<=sizeof(zTemp) ){
2384 assert( zNewRecord==(unsigned char *)zTemp );
2385 pTos->z = pTos->zShort;
2386 memcpy(pTos->zShort, zTemp, nByte);
2387 pTos->flags = MEM_Blob | MEM_Short;
2388 }else{
2389 assert( zNewRecord!=(unsigned char *)zTemp );
2390 pTos->z = (char*)zNewRecord;
2391 pTos->flags = MEM_Blob | MEM_Dyn;
2392 pTos->xDel = 0;
2393 }
2394 if( nZero ){
2395 pTos->u.i = nZero;
2396 pTos->flags |= MEM_Zero;
2397 }
2398 pTos->enc = SQLITE_UTF8; /* In case the blob is ever converted to text */
2399
2400 /* If a NULL was encountered and jumpIfNull is non-zero, take the jump. */
2401 if( jumpIfNull && containsNull ){
2402 pc = jumpIfNull - 1;
2403 }
2404 break;
2405}
2406
2407/* Opcode: Statement P1 * *
2408**
2409** Begin an individual statement transaction which is part of a larger
2410** BEGIN..COMMIT transaction. This is needed so that the statement
2411** can be rolled back after an error without having to roll back the
2412** entire transaction. The statement transaction will automatically
2413** commit when the VDBE halts.
2414**
2415** The statement is begun on the database file with index P1. The main
2416** database file has an index of 0 and the file used for temporary tables
2417** has an index of 1.
2418*/
2419case OP_Statement: { /* no-push */
2420 int i = pOp->p1;
2421 Btree *pBt;
2422 if( i>=0 && i<db->nDb && (pBt = db->aDb[i].pBt)!=0 && !(db->autoCommit) ){
2423 assert( sqlite3BtreeIsInTrans(pBt) );
2424 assert( (p->btreeMask & (1<<i))!=0 );
2425 if( !sqlite3BtreeIsInStmt(pBt) ){
2426 rc = sqlite3BtreeBeginStmt(pBt);
2427 p->openedStatement = 1;
2428 }
2429 }
2430 break;
2431}
2432
2433/* Opcode: AutoCommit P1 P2 *
2434**
2435** Set the database auto-commit flag to P1 (1 or 0). If P2 is true, roll
2436** back any currently active btree transactions. If there are any active
2437** VMs (apart from this one), then the COMMIT or ROLLBACK statement fails.
2438**
2439** This instruction causes the VM to halt.
2440*/
2441case OP_AutoCommit: { /* no-push */
2442 u8 i = pOp->p1;
2443 u8 rollback = pOp->p2;
2444
2445 assert( i==1 || i==0 );
2446 assert( i==1 || rollback==0 );
2447
2448 assert( db->activeVdbeCnt>0 ); /* At least this one VM is active */
2449
2450 if( db->activeVdbeCnt>1 && i && !db->autoCommit ){
2451 /* If this instruction implements a COMMIT or ROLLBACK, other VMs are
2452 ** still running, and a transaction is active, return an error indicating
2453 ** that the other VMs must complete first.
2454 */
2455 sqlite3SetString(&p->zErrMsg, "cannot ", rollback?"rollback":"commit",
2456 " transaction - SQL statements in progress", (char*)0);
2457 rc = SQLITE_ERROR;
2458 }else if( i!=db->autoCommit ){
2459 if( pOp->p2 ){
2460 assert( i==1 );
2461 sqlite3RollbackAll(db);
2462 db->autoCommit = 1;
2463 }else{
2464 db->autoCommit = i;
2465 if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
2466 p->pTos = pTos;
2467 p->pc = pc;
2468 db->autoCommit = 1-i;
2469 p->rc = rc = SQLITE_BUSY;
2470 goto vdbe_return;
2471 }
2472 }
2473 if( p->rc==SQLITE_OK ){
2474 rc = SQLITE_DONE;
2475 }else{
2476 rc = SQLITE_ERROR;
2477 }
2478 goto vdbe_return;
2479 }else{
2480 sqlite3SetString(&p->zErrMsg,
2481 (!i)?"cannot start a transaction within a transaction":(
2482 (rollback)?"cannot rollback - no transaction is active":
2483 "cannot commit - no transaction is active"), (char*)0);
2484
2485 rc = SQLITE_ERROR;
2486 }
2487 break;
2488}
2489
2490/* Opcode: Transaction P1 P2 *
2491**
2492** Begin a transaction. The transaction ends when a Commit or Rollback
2493** opcode is encountered. Depending on the ON CONFLICT setting, the
2494** transaction might also be rolled back if an error is encountered.
2495**
2496** P1 is the index of the database file on which the transaction is
2497** started. Index 0 is the main database file and index 1 is the
2498** file used for temporary tables.
2499**
2500** If P2 is non-zero, then a write-transaction is started. A RESERVED lock is
2501** obtained on the database file when a write-transaction is started. No
2502** other process can start another write transaction while this transaction is
2503** underway. Starting a write transaction also creates a rollback journal. A
2504** write transaction must be started before any changes can be made to the
2505** database. If P2 is 2 or greater then an EXCLUSIVE lock is also obtained
2506** on the file.
2507**
2508** If P2 is zero, then a read-lock is obtained on the database file.
2509*/
2510case OP_Transaction: { /* no-push */
2511 int i = pOp->p1;
2512 Btree *pBt;
2513
2514 assert( i>=0 && i<db->nDb );
2515 assert( (p->btreeMask & (1<<i))!=0 );
2516 pBt = db->aDb[i].pBt;
2517
2518 if( pBt ){
2519 rc = sqlite3BtreeBeginTrans(pBt, pOp->p2);
2520 if( rc==SQLITE_BUSY ){
2521 p->pc = pc;
2522 p->rc = rc = SQLITE_BUSY;
2523 p->pTos = pTos;
2524 goto vdbe_return;
2525 }
2526 if( rc!=SQLITE_OK && rc!=SQLITE_READONLY /* && rc!=SQLITE_BUSY */ ){
2527 goto abort_due_to_error;
2528 }
2529 }
2530 break;
2531}
2532
2533/* Opcode: ReadCookie P1 P2 *
2534**
2535** Read cookie number P2 from database P1 and push it onto the stack.
2536** P2==0 is the schema version. P2==1 is the database format.
2537** P2==2 is the recommended pager cache size, and so forth. P1==0 is
2538** the main database file and P1==1 is the database file used to store
2539** temporary tables.
2540**
2541** If P1 is negative, then this is a request to read the size of a
2542** databases free-list. P2 must be set to 1 in this case. The actual
2543** database accessed is ((P1+1)*-1). For example, a P1 parameter of -1
2544** corresponds to database 0 ("main"), a P1 of -2 is database 1 ("temp").
2545**
2546** There must be a read-lock on the database (either a transaction
2547** must be started or there must be an open cursor) before
2548** executing this instruction.
2549*/
2550case OP_ReadCookie: {
2551 int iMeta;
2552 int iDb = pOp->p1;
2553 int iCookie = pOp->p2;
2554
2555 assert( pOp->p2<SQLITE_N_BTREE_META );
2556 if( iDb<0 ){
2557 iDb = (-1*(iDb+1));
2558 iCookie *= -1;
2559 }
2560 assert( iDb>=0 && iDb<db->nDb );
2561 assert( db->aDb[iDb].pBt!=0 );
2562 assert( (p->btreeMask & (1<<iDb))!=0 );
2563 /* The indexing of meta values at the schema layer is off by one from
2564 ** the indexing in the btree layer. The btree considers meta[0] to
2565 ** be the number of free pages in the database (a read-only value)
2566 ** and meta[1] to be the schema cookie. The schema layer considers
2567 ** meta[1] to be the schema cookie. So we have to shift the index
2568 ** by one in the following statement.
2569 */
2570 rc = sqlite3BtreeGetMeta(db->aDb[iDb].pBt, 1 + iCookie, (u32 *)&iMeta);
2571 pTos++;
2572 pTos->u.i = iMeta;
2573 pTos->flags = MEM_Int;
2574 break;
2575}
2576
2577/* Opcode: SetCookie P1 P2 *
2578**
2579** Write the top of the stack into cookie number P2 of database P1.
2580** P2==0 is the schema version. P2==1 is the database format.
2581** P2==2 is the recommended pager cache size, and so forth. P1==0 is
2582** the main database file and P1==1 is the database file used to store
2583** temporary tables.
2584**
2585** A transaction must be started before executing this opcode.
2586*/
2587case OP_SetCookie: { /* no-push */
2588 Db *pDb;
2589 assert( pOp->p2<SQLITE_N_BTREE_META );
2590 assert( pOp->p1>=0 && pOp->p1<db->nDb );
2591 assert( (p->btreeMask & (1<<pOp->p1))!=0 );
2592 pDb = &db->aDb[pOp->p1];
2593 assert( pDb->pBt!=0 );
2594 assert( pTos>=p->aStack );
2595 sqlite3VdbeMemIntegerify(pTos);
2596 /* See note about index shifting on OP_ReadCookie */
2597 rc = sqlite3BtreeUpdateMeta(pDb->pBt, 1+pOp->p2, (int)pTos->u.i);
2598 if( pOp->p2==0 ){
2599 /* When the schema cookie changes, record the new cookie internally */
2600 pDb->pSchema->schema_cookie = pTos->u.i;
2601 db->flags |= SQLITE_InternChanges;
2602 }else if( pOp->p2==1 ){
2603 /* Record changes in the file format */
2604 pDb->pSchema->file_format = pTos->u.i;
2605 }
2606 assert( (pTos->flags & MEM_Dyn)==0 );
2607 pTos--;
2608 if( pOp->p1==1 ){
2609 /* Invalidate all prepared statements whenever the TEMP database
2610 ** schema is changed. Ticket #1644 */
2611 sqlite3ExpirePreparedStatements(db);
2612 }
2613 break;
2614}
2615
2616/* Opcode: VerifyCookie P1 P2 *
2617**
2618** Check the value of global database parameter number 0 (the
2619** schema version) and make sure it is equal to P2.
2620** P1 is the database number which is 0 for the main database file
2621** and 1 for the file holding temporary tables and some higher number
2622** for auxiliary databases.
2623**
2624** The cookie changes its value whenever the database schema changes.
2625** This operation is used to detect when that the cookie has changed
2626** and that the current process needs to reread the schema.
2627**
2628** Either a transaction needs to have been started or an OP_Open needs
2629** to be executed (to establish a read lock) before this opcode is
2630** invoked.
2631*/
2632case OP_VerifyCookie: { /* no-push */
2633 int iMeta;
2634 Btree *pBt;
2635 assert( pOp->p1>=0 && pOp->p1<db->nDb );
2636 assert( (p->btreeMask & (1<<pOp->p1))!=0 );
2637 pBt = db->aDb[pOp->p1].pBt;
2638 if( pBt ){
2639 rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&iMeta);
2640 }else{
2641 rc = SQLITE_OK;
2642 iMeta = 0;
2643 }
2644 if( rc==SQLITE_OK && iMeta!=pOp->p2 ){
2645 sqlite3_free(p->zErrMsg);
2646 p->zErrMsg = sqlite3DbStrDup(db, "database schema has changed");
2647 /* If the schema-cookie from the database file matches the cookie
2648 ** stored with the in-memory representation of the schema, do
2649 ** not reload the schema from the database file.
2650 **
2651 ** If virtual-tables are in use, this is not just an optimisation.
2652 ** Often, v-tables store their data in other SQLite tables, which
2653 ** are queried from within xNext() and other v-table methods using
2654 ** prepared queries. If such a query is out-of-date, we do not want to
2655 ** discard the database schema, as the user code implementing the
2656 ** v-table would have to be ready for the sqlite3_vtab structure itself
2657 ** to be invalidated whenever sqlite3_step() is called from within
2658 ** a v-table method.
2659 */
2660 if( db->aDb[pOp->p1].pSchema->schema_cookie!=iMeta ){
2661 sqlite3ResetInternalSchema(db, pOp->p1);
2662 }
2663
2664 sqlite3ExpirePreparedStatements(db);
2665 rc = SQLITE_SCHEMA;
2666 }
2667 break;
2668}
2669
2670/* Opcode: OpenRead P1 P2 P3
2671**
2672** Open a read-only cursor for the database table whose root page is
2673** P2 in a database file. The database file is determined by an
2674** integer from the top of the stack. 0 means the main database and
2675** 1 means the database used for temporary tables. Give the new
2676** cursor an identifier of P1. The P1 values need not be contiguous
2677** but all P1 values should be small integers. It is an error for
2678** P1 to be negative.
2679**
2680** If P2==0 then take the root page number from the next of the stack.
2681**
2682** There will be a read lock on the database whenever there is an
2683** open cursor. If the database was unlocked prior to this instruction
2684** then a read lock is acquired as part of this instruction. A read
2685** lock allows other processes to read the database but prohibits
2686** any other process from modifying the database. The read lock is
2687** released when all cursors are closed. If this instruction attempts
2688** to get a read lock but fails, the script terminates with an
2689** SQLITE_BUSY error code.
2690**
2691** The P3 value is a pointer to a KeyInfo structure that defines the
2692** content and collating sequence of indices. P3 is NULL for cursors
2693** that are not pointing to indices.
2694**
2695** See also OpenWrite.
2696*/
2697/* Opcode: OpenWrite P1 P2 P3
2698**
2699** Open a read/write cursor named P1 on the table or index whose root
2700** page is P2. If P2==0 then take the root page number from the stack.
2701**
2702** The P3 value is a pointer to a KeyInfo structure that defines the
2703** content and collating sequence of indices. P3 is NULL for cursors
2704** that are not pointing to indices.
2705**
2706** This instruction works just like OpenRead except that it opens the cursor
2707** in read/write mode. For a given table, there can be one or more read-only
2708** cursors or a single read/write cursor but not both.
2709**
2710** See also OpenRead.
2711*/
2712case OP_OpenRead: /* no-push */
2713case OP_OpenWrite: { /* no-push */
2714 int i = pOp->p1;
2715 int p2 = pOp->p2;
2716 int wrFlag;
2717 Btree *pX;
2718 int iDb;
2719 Cursor *pCur;
2720 Db *pDb;
2721
2722 assert( pTos>=p->aStack );
2723 sqlite3VdbeMemIntegerify(pTos);
2724 iDb = pTos->u.i;
2725 assert( (pTos->flags & MEM_Dyn)==0 );
2726 pTos--;
2727 assert( iDb>=0 && iDb<db->nDb );
2728 assert( (p->btreeMask & (1<<iDb))!=0 );
2729 pDb = &db->aDb[iDb];
2730 pX = pDb->pBt;
2731 assert( pX!=0 );
2732 if( pOp->opcode==OP_OpenWrite ){
2733 wrFlag = 1;
2734 if( pDb->pSchema->file_format < p->minWriteFileFormat ){
2735 p->minWriteFileFormat = pDb->pSchema->file_format;
2736 }
2737 }else{
2738 wrFlag = 0;
2739 }
2740 if( p2<=0 ){
2741 assert( pTos>=p->aStack );
2742 sqlite3VdbeMemIntegerify(pTos);
2743 p2 = pTos->u.i;
2744 assert( (pTos->flags & MEM_Dyn)==0 );
2745 pTos--;
2746 assert( p2>=2 );
2747 }
2748 assert( i>=0 );
2749 pCur = allocateCursor(p, i, iDb);
2750 if( pCur==0 ) goto no_mem;
2751 pCur->nullRow = 1;
2752 if( pX==0 ) break;
2753 /* We always provide a key comparison function. If the table being
2754 ** opened is of type INTKEY, the comparision function will be ignored. */
2755 rc = sqlite3BtreeCursor(pX, p2, wrFlag,
2756 sqlite3VdbeRecordCompare, pOp->p3,
2757 &pCur->pCursor);
2758 if( pOp->p3type==P3_KEYINFO ){
2759 pCur->pKeyInfo = (KeyInfo*)pOp->p3;
2760 pCur->pIncrKey = &pCur->pKeyInfo->incrKey;
2761 pCur->pKeyInfo->enc = ENC(p->db);
2762 }else{
2763 pCur->pKeyInfo = 0;
2764 pCur->pIncrKey = &pCur->bogusIncrKey;
2765 }
2766 switch( rc ){
2767 case SQLITE_BUSY: {
2768 p->pc = pc;
2769 p->rc = rc = SQLITE_BUSY;
2770 p->pTos = &pTos[1 + (pOp->p2<=0)]; /* Operands must remain on stack */
2771 goto vdbe_return;
2772 }
2773 case SQLITE_OK: {
2774 int flags = sqlite3BtreeFlags(pCur->pCursor);
2775 /* Sanity checking. Only the lower four bits of the flags byte should
2776 ** be used. Bit 3 (mask 0x08) is unpreditable. The lower 3 bits
2777 ** (mask 0x07) should be either 5 (intkey+leafdata for tables) or
2778 ** 2 (zerodata for indices). If these conditions are not met it can
2779 ** only mean that we are dealing with a corrupt database file
2780 */
2781 if( (flags & 0xf0)!=0 || ((flags & 0x07)!=5 && (flags & 0x07)!=2) ){
2782 rc = SQLITE_CORRUPT_BKPT;
2783 goto abort_due_to_error;
2784 }
2785 pCur->isTable = (flags & BTREE_INTKEY)!=0;
2786 pCur->isIndex = (flags & BTREE_ZERODATA)!=0;
2787 /* If P3==0 it means we are expected to open a table. If P3!=0 then
2788 ** we expect to be opening an index. If this is not what happened,
2789 ** then the database is corrupt
2790 */
2791 if( (pCur->isTable && pOp->p3type==P3_KEYINFO)
2792 || (pCur->isIndex && pOp->p3type!=P3_KEYINFO) ){
2793 rc = SQLITE_CORRUPT_BKPT;
2794 goto abort_due_to_error;
2795 }
2796 break;
2797 }
2798 case SQLITE_EMPTY: {
2799 pCur->isTable = pOp->p3type!=P3_KEYINFO;
2800 pCur->isIndex = !pCur->isTable;
2801 rc = SQLITE_OK;
2802 break;
2803 }
2804 default: {
2805 goto abort_due_to_error;
2806 }
2807 }
2808 break;
2809}
2810
2811/* Opcode: OpenEphemeral P1 P2 P3
2812**
2813** Open a new cursor P1 to a transient table.
2814** The cursor is always opened read/write even if
2815** the main database is read-only. The transient or virtual
2816** table is deleted automatically when the cursor is closed.
2817**
2818** P2 is the number of columns in the virtual table.
2819** The cursor points to a BTree table if P3==0 and to a BTree index
2820** if P3 is not 0. If P3 is not NULL, it points to a KeyInfo structure
2821** that defines the format of keys in the index.
2822**
2823** This opcode was once called OpenTemp. But that created
2824** confusion because the term "temp table", might refer either
2825** to a TEMP table at the SQL level, or to a table opened by
2826** this opcode. Then this opcode was call OpenVirtual. But
2827** that created confusion with the whole virtual-table idea.
2828*/
2829case OP_OpenEphemeral: { /* no-push */
2830 int i = pOp->p1;
2831 Cursor *pCx;
2832 static const int openFlags =
2833 SQLITE_OPEN_READWRITE |
2834 SQLITE_OPEN_CREATE |
2835 SQLITE_OPEN_EXCLUSIVE |
2836 SQLITE_OPEN_DELETEONCLOSE |
2837 SQLITE_OPEN_TRANSIENT_DB;
2838
2839 assert( i>=0 );
2840 pCx = allocateCursor(p, i, -1);
2841 if( pCx==0 ) goto no_mem;
2842 pCx->nullRow = 1;
2843 rc = sqlite3BtreeFactory(db, 0, 1, SQLITE_DEFAULT_TEMP_CACHE_SIZE, openFlags,
2844 &pCx->pBt);
2845 if( rc==SQLITE_OK ){
2846 rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);
2847 }
2848 if( rc==SQLITE_OK ){
2849 /* If a transient index is required, create it by calling
2850 ** sqlite3BtreeCreateTable() with the BTREE_ZERODATA flag before
2851 ** opening it. If a transient table is required, just use the
2852 ** automatically created table with root-page 1 (an INTKEY table).
2853 */
2854 if( pOp->p3 ){
2855 int pgno;
2856 assert( pOp->p3type==P3_KEYINFO );
2857 rc = sqlite3BtreeCreateTable(pCx->pBt, &pgno, BTREE_ZERODATA);
2858 if( rc==SQLITE_OK ){
2859 assert( pgno==MASTER_ROOT+1 );
2860 rc = sqlite3BtreeCursor(pCx->pBt, pgno, 1, sqlite3VdbeRecordCompare,
2861 pOp->p3, &pCx->pCursor);
2862 pCx->pKeyInfo = (KeyInfo*)pOp->p3;
2863 pCx->pKeyInfo->enc = ENC(p->db);
2864 pCx->pIncrKey = &pCx->pKeyInfo->incrKey;
2865 }
2866 pCx->isTable = 0;
2867 }else{
2868 rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, 1, 0, 0, &pCx->pCursor);
2869 pCx->isTable = 1;
2870 pCx->pIncrKey = &pCx->bogusIncrKey;
2871 }
2872 }
2873 pCx->nField = pOp->p2;
2874 pCx->isIndex = !pCx->isTable;
2875 break;
2876}
2877
2878/* Opcode: OpenPseudo P1 * *
2879**
2880** Open a new cursor that points to a fake table that contains a single
2881** row of data. Any attempt to write a second row of data causes the
2882** first row to be deleted. All data is deleted when the cursor is
2883** closed.
2884**
2885** A pseudo-table created by this opcode is useful for holding the
2886** NEW or OLD tables in a trigger. Also used to hold the a single
2887** row output from the sorter so that the row can be decomposed into
2888** individual columns using the OP_Column opcode.
2889*/
2890case OP_OpenPseudo: { /* no-push */
2891 int i = pOp->p1;
2892 Cursor *pCx;
2893 assert( i>=0 );
2894 pCx = allocateCursor(p, i, -1);
2895 if( pCx==0 ) goto no_mem;
2896 pCx->nullRow = 1;
2897 pCx->pseudoTable = 1;
2898 pCx->pIncrKey = &pCx->bogusIncrKey;
2899 pCx->isTable = 1;
2900 pCx->isIndex = 0;
2901 break;
2902}
2903
2904/* Opcode: Close P1 * *
2905**
2906** Close a cursor previously opened as P1. If P1 is not
2907** currently open, this instruction is a no-op.
2908*/
2909case OP_Close: { /* no-push */
2910 int i = pOp->p1;
2911 if( i>=0 && i<p->nCursor ){
2912 sqlite3VdbeFreeCursor(p, p->apCsr[i]);
2913 p->apCsr[i] = 0;
2914 }
2915 break;
2916}
2917
2918/* Opcode: MoveGe P1 P2 *
2919**
2920** Pop the top of the stack and use its value as a key. Reposition
2921** cursor P1 so that it points to the smallest entry that is greater
2922** than or equal to the key that was popped ffrom the stack.
2923** If there are no records greater than or equal to the key and P2
2924** is not zero, then jump to P2.
2925**
2926** See also: Found, NotFound, Distinct, MoveLt, MoveGt, MoveLe
2927*/
2928/* Opcode: MoveGt P1 P2 *
2929**
2930** Pop the top of the stack and use its value as a key. Reposition
2931** cursor P1 so that it points to the smallest entry that is greater
2932** than the key from the stack.
2933** If there are no records greater than the key and P2 is not zero,
2934** then jump to P2.
2935**
2936** See also: Found, NotFound, Distinct, MoveLt, MoveGe, MoveLe
2937*/
2938/* Opcode: MoveLt P1 P2 *
2939**
2940** Pop the top of the stack and use its value as a key. Reposition
2941** cursor P1 so that it points to the largest entry that is less
2942** than the key from the stack.
2943** If there are no records less than the key and P2 is not zero,
2944** then jump to P2.
2945**
2946** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLe
2947*/
2948/* Opcode: MoveLe P1 P2 *
2949**
2950** Pop the top of the stack and use its value as a key. Reposition
2951** cursor P1 so that it points to the largest entry that is less than
2952** or equal to the key that was popped from the stack.
2953** If there are no records less than or eqal to the key and P2 is not zero,
2954** then jump to P2.
2955**
2956** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLt
2957*/
2958case OP_MoveLt: /* no-push */
2959case OP_MoveLe: /* no-push */
2960case OP_MoveGe: /* no-push */
2961case OP_MoveGt: { /* no-push */
2962 int i = pOp->p1;
2963 Cursor *pC;
2964
2965 assert( pTos>=p->aStack );
2966 assert( i>=0 && i<p->nCursor );
2967 pC = p->apCsr[i];
2968 assert( pC!=0 );
2969 if( pC->pCursor!=0 ){
2970 int res, oc;
2971 oc = pOp->opcode;
2972 pC->nullRow = 0;
2973 *pC->pIncrKey = oc==OP_MoveGt || oc==OP_MoveLe;
2974 if( pC->isTable ){
2975 i64 iKey;
2976 sqlite3VdbeMemIntegerify(pTos);
2977 iKey = intToKey(pTos->u.i);
2978 if( pOp->p2==0 && pOp->opcode==OP_MoveGe ){
2979 pC->movetoTarget = iKey;
2980 pC->deferredMoveto = 1;
2981 assert( (pTos->flags & MEM_Dyn)==0 );
2982 pTos--;
2983 break;
2984 }
2985 rc = sqlite3BtreeMoveto(pC->pCursor, 0, (u64)iKey, 0, &res);
2986 if( rc!=SQLITE_OK ){
2987 goto abort_due_to_error;
2988 }
2989 pC->lastRowid = pTos->u.i;
2990 pC->rowidIsValid = res==0;
2991 }else{
2992 assert( pTos->flags & MEM_Blob );
2993 ExpandBlob(pTos);
2994 rc = sqlite3BtreeMoveto(pC->pCursor, pTos->z, pTos->n, 0, &res);
2995 if( rc!=SQLITE_OK ){
2996 goto abort_due_to_error;
2997 }
2998 pC->rowidIsValid = 0;
2999 }
3000 pC->deferredMoveto = 0;
3001 pC->cacheStatus = CACHE_STALE;
3002 *pC->pIncrKey = 0;
3003#ifdef SQLITE_TEST
3004 sqlite3_search_count++;
3005#endif
3006 if( oc==OP_MoveGe || oc==OP_MoveGt ){
3007 if( res<0 ){
3008 rc = sqlite3BtreeNext(pC->pCursor, &res);
3009 if( rc!=SQLITE_OK ) goto abort_due_to_error;
3010 pC->rowidIsValid = 0;
3011 }else{
3012 res = 0;
3013 }
3014 }else{
3015 assert( oc==OP_MoveLt || oc==OP_MoveLe );
3016 if( res>=0 ){
3017 rc = sqlite3BtreePrevious(pC->pCursor, &res);
3018 if( rc!=SQLITE_OK ) goto abort_due_to_error;
3019 pC->rowidIsValid = 0;
3020 }else{
3021 /* res might be negative because the table is empty. Check to
3022 ** see if this is the case.
3023 */
3024 res = sqlite3BtreeEof(pC->pCursor);
3025 }
3026 }
3027 if( res ){
3028 if( pOp->p2>0 ){
3029 pc = pOp->p2 - 1;
3030 }else{
3031 pC->nullRow = 1;
3032 }
3033 }
3034 }
3035 Release(pTos);
3036 pTos--;
3037 break;
3038}
3039
3040/* Opcode: Distinct P1 P2 *
3041**
3042** Use the top of the stack as a record created using MakeRecord. P1 is a
3043** cursor on a table that declared as an index. If that table contains an
3044** entry that matches the top of the stack fall thru. If the top of the stack
3045** matches no entry in P1 then jump to P2.
3046**
3047** The cursor is left pointing at the matching entry if it exists. The
3048** record on the top of the stack is not popped.
3049**
3050** This instruction is similar to NotFound except that this operation
3051** does not pop the key from the stack.
3052**
3053** The instruction is used to implement the DISTINCT operator on SELECT
3054** statements. The P1 table is not a true index but rather a record of
3055** all results that have produced so far.
3056**
3057** See also: Found, NotFound, MoveTo, IsUnique, NotExists
3058*/
3059/* Opcode: Found P1 P2 *
3060**
3061** Top of the stack holds a blob constructed by MakeRecord. P1 is an index.
3062** If an entry that matches the top of the stack exists in P1 then
3063** jump to P2. If the top of the stack does not match any entry in P1
3064** then fall thru. The P1 cursor is left pointing at the matching entry
3065** if it exists. The blob is popped off the top of the stack.
3066**
3067** This instruction is used to implement the IN operator where the
3068** left-hand side is a SELECT statement. P1 is not a true index but
3069** is instead a temporary index that holds the results of the SELECT
3070** statement. This instruction just checks to see if the left-hand side
3071** of the IN operator (stored on the top of the stack) exists in the
3072** result of the SELECT statement.
3073**
3074** See also: Distinct, NotFound, MoveTo, IsUnique, NotExists
3075*/
3076/* Opcode: NotFound P1 P2 *
3077**
3078** The top of the stack holds a blob constructed by MakeRecord. P1 is
3079** an index. If no entry exists in P1 that matches the blob then jump
3080** to P2. If an entry does existing, fall through. The cursor is left
3081** pointing to the entry that matches. The blob is popped from the stack.
3082**
3083** The difference between this operation and Distinct is that
3084** Distinct does not pop the key from the stack.
3085**
3086** See also: Distinct, Found, MoveTo, NotExists, IsUnique
3087*/
3088case OP_Distinct: /* no-push */
3089case OP_NotFound: /* no-push */
3090case OP_Found: { /* no-push */
3091 int i = pOp->p1;
3092 int alreadyExists = 0;
3093 Cursor *pC;
3094 assert( pTos>=p->aStack );
3095 assert( i>=0 && i<p->nCursor );
3096 assert( p->apCsr[i]!=0 );
3097 if( (pC = p->apCsr[i])->pCursor!=0 ){
3098 int res;
3099 assert( pC->isTable==0 );
3100 assert( pTos->flags & MEM_Blob );
3101 Stringify(pTos, encoding);
3102 rc = sqlite3BtreeMoveto(pC->pCursor, pTos->z, pTos->n, 0, &res);
3103 if( rc!=SQLITE_OK ){
3104 break;
3105 }
3106 alreadyExists = (res==0);
3107 pC->deferredMoveto = 0;
3108 pC->cacheStatus = CACHE_STALE;
3109 }
3110 if( pOp->opcode==OP_Found ){
3111 if( alreadyExists ) pc = pOp->p2 - 1;
3112 }else{
3113 if( !alreadyExists ) pc = pOp->p2 - 1;
3114 }
3115 if( pOp->opcode!=OP_Distinct ){
3116 Release(pTos);
3117 pTos--;
3118 }
3119 break;
3120}
3121
3122/* Opcode: IsUnique P1 P2 *
3123**
3124** The top of the stack is an integer record number. Call this
3125** record number R. The next on the stack is an index key created
3126** using MakeIdxRec. Call it K. This instruction pops R from the
3127** stack but it leaves K unchanged.
3128**
3129** P1 is an index. So it has no data and its key consists of a
3130** record generated by OP_MakeRecord where the last field is the
3131** rowid of the entry that the index refers to.
3132**
3133** This instruction asks if there is an entry in P1 where the
3134** fields matches K but the rowid is different from R.
3135** If there is no such entry, then there is an immediate
3136** jump to P2. If any entry does exist where the index string
3137** matches K but the record number is not R, then the record
3138** number for that entry is pushed onto the stack and control
3139** falls through to the next instruction.
3140**
3141** See also: Distinct, NotFound, NotExists, Found
3142*/
3143case OP_IsUnique: { /* no-push */
3144 int i = pOp->p1;
3145 Mem *pNos = &pTos[-1];
3146 Cursor *pCx;
3147 BtCursor *pCrsr;
3148 i64 R;
3149
3150 /* Pop the value R off the top of the stack
3151 */
3152 assert( pNos>=p->aStack );
3153 sqlite3VdbeMemIntegerify(pTos);
3154 R = pTos->u.i;
3155 assert( (pTos->flags & MEM_Dyn)==0 );
3156 pTos--;
3157 assert( i>=0 && i<p->nCursor );
3158 pCx = p->apCsr[i];
3159 assert( pCx!=0 );
3160 pCrsr = pCx->pCursor;
3161 if( pCrsr!=0 ){
3162 int res;
3163 i64 v; /* The record number on the P1 entry that matches K */
3164 char *zKey; /* The value of K */
3165 int nKey; /* Number of bytes in K */
3166 int len; /* Number of bytes in K without the rowid at the end */
3167 int szRowid; /* Size of the rowid column at the end of zKey */
3168
3169 /* Make sure K is a string and make zKey point to K
3170 */
3171 assert( pNos->flags & MEM_Blob );
3172 Stringify(pNos, encoding);
3173 zKey = pNos->z;
3174 nKey = pNos->n;
3175
3176 szRowid = sqlite3VdbeIdxRowidLen((u8*)zKey);
3177 len = nKey-szRowid;
3178
3179 /* Search for an entry in P1 where all but the last four bytes match K.
3180 ** If there is no such entry, jump immediately to P2.
3181 */
3182 assert( pCx->deferredMoveto==0 );
3183 pCx->cacheStatus = CACHE_STALE;
3184 rc = sqlite3BtreeMoveto(pCrsr, zKey, len, 0, &res);
3185 if( rc!=SQLITE_OK ){
3186 goto abort_due_to_error;
3187 }
3188 if( res<0 ){
3189 rc = sqlite3BtreeNext(pCrsr, &res);
3190 if( res ){
3191 pc = pOp->p2 - 1;
3192 break;
3193 }
3194 }
3195 rc = sqlite3VdbeIdxKeyCompare(pCx, len, (u8*)zKey, &res);
3196 if( rc!=SQLITE_OK ) goto abort_due_to_error;
3197 if( res>0 ){
3198 pc = pOp->p2 - 1;
3199 break;
3200 }
3201
3202 /* At this point, pCrsr is pointing to an entry in P1 where all but
3203 ** the final entry (the rowid) matches K. Check to see if the
3204 ** final rowid column is different from R. If it equals R then jump
3205 ** immediately to P2.
3206 */
3207 rc = sqlite3VdbeIdxRowid(pCrsr, &v);
3208 if( rc!=SQLITE_OK ){
3209 goto abort_due_to_error;
3210 }
3211 if( v==R ){
3212 pc = pOp->p2 - 1;
3213 break;
3214 }
3215
3216 /* The final varint of the key is different from R. Push it onto
3217 ** the stack. (The record number of an entry that violates a UNIQUE
3218 ** constraint.)
3219 */
3220 pTos++;
3221 pTos->u.i = v;
3222 pTos->flags = MEM_Int;
3223 }
3224 break;
3225}
3226
3227/* Opcode: NotExists P1 P2 *
3228**
3229** Use the top of the stack as a integer key. If a record with that key
3230** does not exist in table of P1, then jump to P2. If the record
3231** does exist, then fall thru. The cursor is left pointing to the
3232** record if it exists. The integer key is popped from the stack.
3233**
3234** The difference between this operation and NotFound is that this
3235** operation assumes the key is an integer and that P1 is a table whereas
3236** NotFound assumes key is a blob constructed from MakeRecord and
3237** P1 is an index.
3238**
3239** See also: Distinct, Found, MoveTo, NotFound, IsUnique
3240*/
3241case OP_NotExists: { /* no-push */
3242 int i = pOp->p1;
3243 Cursor *pC;
3244 BtCursor *pCrsr;
3245 assert( pTos>=p->aStack );
3246 assert( i>=0 && i<p->nCursor );
3247 assert( p->apCsr[i]!=0 );
3248 if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
3249 int res;
3250 u64 iKey;
3251 assert( pTos->flags & MEM_Int );
3252 assert( p->apCsr[i]->isTable );
3253 iKey = intToKey(pTos->u.i);
3254 rc = sqlite3BtreeMoveto(pCrsr, 0, iKey, 0,&res);
3255 pC->lastRowid = pTos->u.i;
3256 pC->rowidIsValid = res==0;
3257 pC->nullRow = 0;
3258 pC->cacheStatus = CACHE_STALE;
3259 /* res might be uninitialized if rc!=SQLITE_OK. But if rc!=SQLITE_OK
3260 ** processing is about to abort so we really do not care whether or not
3261 ** the following jump is taken. (In other words, do not stress over
3262 ** the error that valgrind sometimes shows on the next statement when
3263 ** running ioerr.test and similar failure-recovery test scripts.) */
3264 if( res!=0 ){
3265 pc = pOp->p2 - 1;
3266 pC->rowidIsValid = 0;
3267 }
3268 }
3269 Release(pTos);
3270 pTos--;
3271 break;
3272}
3273
3274/* Opcode: Sequence P1 * *
3275**
3276** Push an integer onto the stack which is the next available
3277** sequence number for cursor P1. The sequence number on the
3278** cursor is incremented after the push.
3279*/
3280case OP_Sequence: {
3281 int i = pOp->p1;
3282 assert( pTos>=p->aStack );
3283 assert( i>=0 && i<p->nCursor );
3284 assert( p->apCsr[i]!=0 );
3285 pTos++;
3286 pTos->u.i = p->apCsr[i]->seqCount++;
3287 pTos->flags = MEM_Int;
3288 break;
3289}
3290
3291
3292/* Opcode: NewRowid P1 P2 *
3293**
3294** Get a new integer record number (a.k.a "rowid") used as the key to a table.
3295** The record number is not previously used as a key in the database
3296** table that cursor P1 points to. The new record number is pushed
3297** onto the stack.
3298**
3299** If P2>0 then P2 is a memory cell that holds the largest previously
3300** generated record number. No new record numbers are allowed to be less
3301** than this value. When this value reaches its maximum, a SQLITE_FULL
3302** error is generated. The P2 memory cell is updated with the generated
3303** record number. This P2 mechanism is used to help implement the
3304** AUTOINCREMENT feature.
3305*/
3306case OP_NewRowid: {
3307 int i = pOp->p1;
3308 i64 v = 0;
3309 Cursor *pC;
3310 assert( i>=0 && i<p->nCursor );
3311 assert( p->apCsr[i]!=0 );
3312 if( (pC = p->apCsr[i])->pCursor==0 ){
3313 /* The zero initialization above is all that is needed */
3314 }else{
3315 /* The next rowid or record number (different terms for the same
3316 ** thing) is obtained in a two-step algorithm.
3317 **
3318 ** First we attempt to find the largest existing rowid and add one
3319 ** to that. But if the largest existing rowid is already the maximum
3320 ** positive integer, we have to fall through to the second
3321 ** probabilistic algorithm
3322 **
3323 ** The second algorithm is to select a rowid at random and see if
3324 ** it already exists in the table. If it does not exist, we have
3325 ** succeeded. If the random rowid does exist, we select a new one
3326 ** and try again, up to 1000 times.
3327 **
3328 ** For a table with less than 2 billion entries, the probability
3329 ** of not finding a unused rowid is about 1.0e-300. This is a
3330 ** non-zero probability, but it is still vanishingly small and should
3331 ** never cause a problem. You are much, much more likely to have a
3332 ** hardware failure than for this algorithm to fail.
3333 **
3334 ** The analysis in the previous paragraph assumes that you have a good
3335 ** source of random numbers. Is a library function like lrand48()
3336 ** good enough? Maybe. Maybe not. It's hard to know whether there
3337 ** might be subtle bugs is some implementations of lrand48() that
3338 ** could cause problems. To avoid uncertainty, SQLite uses its own
3339 ** random number generator based on the RC4 algorithm.
3340 **
3341 ** To promote locality of reference for repetitive inserts, the
3342 ** first few attempts at chosing a random rowid pick values just a little
3343 ** larger than the previous rowid. This has been shown experimentally
3344 ** to double the speed of the COPY operation.
3345 */
3346 int res, rx=SQLITE_OK, cnt;
3347 i64 x;
3348 cnt = 0;
3349 if( (sqlite3BtreeFlags(pC->pCursor)&(BTREE_INTKEY|BTREE_ZERODATA)) !=
3350 BTREE_INTKEY ){
3351 rc = SQLITE_CORRUPT_BKPT;
3352 goto abort_due_to_error;
3353 }
3354 assert( (sqlite3BtreeFlags(pC->pCursor) & BTREE_INTKEY)!=0 );
3355 assert( (sqlite3BtreeFlags(pC->pCursor) & BTREE_ZERODATA)==0 );
3356
3357#ifdef SQLITE_32BIT_ROWID
3358# define MAX_ROWID 0x7fffffff
3359#else
3360 /* Some compilers complain about constants of the form 0x7fffffffffffffff.
3361 ** Others complain about 0x7ffffffffffffffffLL. The following macro seems
3362 ** to provide the constant while making all compilers happy.
3363 */
3364# define MAX_ROWID ( (((u64)0x7fffffff)<<32) | (u64)0xffffffff )
3365#endif
3366
3367 if( !pC->useRandomRowid ){
3368 if( pC->nextRowidValid ){
3369 v = pC->nextRowid;
3370 }else{
3371 rc = sqlite3BtreeLast(pC->pCursor, &res);
3372 if( rc!=SQLITE_OK ){
3373 goto abort_due_to_error;
3374 }
3375 if( res ){
3376 v = 1;
3377 }else{
3378 sqlite3BtreeKeySize(pC->pCursor, &v);
3379 v = keyToInt(v);
3380 if( v==MAX_ROWID ){
3381 pC->useRandomRowid = 1;
3382 }else{
3383 v++;
3384 }
3385 }
3386 }
3387
3388#ifndef SQLITE_OMIT_AUTOINCREMENT
3389 if( pOp->p2 ){
3390 Mem *pMem;
3391 assert( pOp->p2>0 && pOp->p2<p->nMem ); /* P2 is a valid memory cell */
3392 pMem = &p->aMem[pOp->p2];
3393 sqlite3VdbeMemIntegerify(pMem);
3394 assert( (pMem->flags & MEM_Int)!=0 ); /* mem(P2) holds an integer */
3395 if( pMem->u.i==MAX_ROWID || pC->useRandomRowid ){
3396 rc = SQLITE_FULL;
3397 goto abort_due_to_error;
3398 }
3399 if( v<pMem->u.i+1 ){
3400 v = pMem->u.i + 1;
3401 }
3402 pMem->u.i = v;
3403 }
3404#endif
3405
3406 if( v<MAX_ROWID ){
3407 pC->nextRowidValid = 1;
3408 pC->nextRowid = v+1;
3409 }else{
3410 pC->nextRowidValid = 0;
3411 }
3412 }
3413 if( pC->useRandomRowid ){
3414 assert( pOp->p2==0 ); /* SQLITE_FULL must have occurred prior to this */
3415 v = db->priorNewRowid;
3416 cnt = 0;
3417 do{
3418 if( v==0 || cnt>2 ){
3419 sqlite3Randomness(sizeof(v), &v);
3420 if( cnt<5 ) v &= 0xffffff;
3421 }else{
3422 unsigned char r;
3423 sqlite3Randomness(1, &r);
3424 v += r + 1;
3425 }
3426 if( v==0 ) continue;
3427 x = intToKey(v);
3428 rx = sqlite3BtreeMoveto(pC->pCursor, 0, (u64)x, 0, &res);
3429 cnt++;
3430 }while( cnt<1000 && rx==SQLITE_OK && res==0 );
3431 db->priorNewRowid = v;
3432 if( rx==SQLITE_OK && res==0 ){
3433 rc = SQLITE_FULL;
3434 goto abort_due_to_error;
3435 }
3436 }
3437 pC->rowidIsValid = 0;
3438 pC->deferredMoveto = 0;
3439 pC->cacheStatus = CACHE_STALE;
3440 }
3441 pTos++;
3442 pTos->u.i = v;
3443 pTos->flags = MEM_Int;
3444 break;
3445}
3446
3447/* Opcode: Insert P1 P2 P3
3448**
3449** Write an entry into the table of cursor P1. A new entry is
3450** created if it doesn't already exist or the data for an existing
3451** entry is overwritten. The data is the value on the top of the
3452** stack. The key is the next value down on the stack. The key must
3453** be an integer. The stack is popped twice by this instruction.
3454**
3455** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
3456** incremented (otherwise not). If the OPFLAG_LASTROWID flag of P2 is set,
3457** then rowid is stored for subsequent return by the
3458** sqlite3_last_insert_rowid() function (otherwise it's unmodified).
3459**
3460** Parameter P3 may point to a string containing the table-name, or
3461** may be NULL. If it is not NULL, then the update-hook
3462** (sqlite3.xUpdateCallback) is invoked following a successful insert.
3463**
3464** This instruction only works on tables. The equivalent instruction
3465** for indices is OP_IdxInsert.
3466*/
3467case OP_Insert: { /* no-push */
3468 Mem *pNos = &pTos[-1];
3469 int i = pOp->p1;
3470 Cursor *pC;
3471 assert( pNos>=p->aStack );
3472 assert( i>=0 && i<p->nCursor );
3473 assert( p->apCsr[i]!=0 );
3474 if( ((pC = p->apCsr[i])->pCursor!=0 || pC->pseudoTable) ){
3475 i64 iKey; /* The integer ROWID or key for the record to be inserted */
3476
3477 assert( pNos->flags & MEM_Int );
3478 assert( pC->isTable );
3479 iKey = intToKey(pNos->u.i);
3480
3481 if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
3482 if( pOp->p2 & OPFLAG_LASTROWID ) db->lastRowid = pNos->u.i;
3483 if( pC->nextRowidValid && pNos->u.i>=pC->nextRowid ){
3484 pC->nextRowidValid = 0;
3485 }
3486 if( pTos->flags & MEM_Null ){
3487 pTos->z = 0;
3488 pTos->n = 0;
3489 }else{
3490 assert( pTos->flags & (MEM_Blob|MEM_Str) );
3491 }
3492 if( pC->pseudoTable ){
3493 sqlite3_free(pC->pData);
3494 pC->iKey = iKey;
3495 pC->nData = pTos->n;
3496 if( pTos->flags & MEM_Dyn ){
3497 pC->pData = pTos->z;
3498 pTos->flags = MEM_Null;
3499 }else{
3500 pC->pData = sqlite3_malloc( pC->nData+2 );
3501 if( !pC->pData ) goto no_mem;
3502 memcpy(pC->pData, pTos->z, pC->nData);
3503 pC->pData[pC->nData] = 0;
3504 pC->pData[pC->nData+1] = 0;
3505 }
3506 pC->nullRow = 0;
3507 }else{
3508 int nZero;
3509 if( pTos->flags & MEM_Zero ){
3510 nZero = pTos->u.i;
3511 }else{
3512 nZero = 0;
3513 }
3514 rc = sqlite3BtreeInsert(pC->pCursor, 0, iKey,
3515 pTos->z, pTos->n, nZero,
3516 pOp->p2 & OPFLAG_APPEND);
3517 }
3518
3519 pC->rowidIsValid = 0;
3520 pC->deferredMoveto = 0;
3521 pC->cacheStatus = CACHE_STALE;
3522
3523 /* Invoke the update-hook if required. */
3524 if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p3 ){
3525 const char *zDb = db->aDb[pC->iDb].zName;
3526 const char *zTbl = pOp->p3;
3527 int op = ((pOp->p2 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
3528 assert( pC->isTable );
3529 db->xUpdateCallback(db->pUpdateArg, op, zDb, zTbl, iKey);
3530 assert( pC->iDb>=0 );
3531 }
3532 }
3533 popStack(&pTos, 2);
3534
3535 break;
3536}
3537
3538/* Opcode: Delete P1 P2 P3
3539**
3540** Delete the record at which the P1 cursor is currently pointing.
3541**
3542** The cursor will be left pointing at either the next or the previous
3543** record in the table. If it is left pointing at the next record, then
3544** the next Next instruction will be a no-op. Hence it is OK to delete
3545** a record from within an Next loop.
3546**
3547** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
3548** incremented (otherwise not).
3549**
3550** If P1 is a pseudo-table, then this instruction is a no-op.
3551*/
3552case OP_Delete: { /* no-push */
3553 int i = pOp->p1;
3554 Cursor *pC;
3555 assert( i>=0 && i<p->nCursor );
3556 pC = p->apCsr[i];
3557 assert( pC!=0 );
3558 if( pC->pCursor!=0 ){
3559 i64 iKey;
3560
3561 /* If the update-hook will be invoked, set iKey to the rowid of the
3562 ** row being deleted.
3563 */
3564 if( db->xUpdateCallback && pOp->p3 ){
3565 assert( pC->isTable );
3566 if( pC->rowidIsValid ){
3567 iKey = pC->lastRowid;
3568 }else{
3569 rc = sqlite3BtreeKeySize(pC->pCursor, &iKey);
3570 if( rc ){
3571 goto abort_due_to_error;
3572 }
3573 iKey = keyToInt(iKey);
3574 }
3575 }
3576
3577 rc = sqlite3VdbeCursorMoveto(pC);
3578 if( rc ) goto abort_due_to_error;
3579 rc = sqlite3BtreeDelete(pC->pCursor);
3580 pC->nextRowidValid = 0;
3581 pC->cacheStatus = CACHE_STALE;
3582
3583 /* Invoke the update-hook if required. */
3584 if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p3 ){
3585 const char *zDb = db->aDb[pC->iDb].zName;
3586 const char *zTbl = pOp->p3;
3587 db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, zTbl, iKey);
3588 assert( pC->iDb>=0 );
3589 }
3590 }
3591 if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
3592 break;
3593}
3594
3595/* Opcode: ResetCount P1 * *
3596**
3597** This opcode resets the VMs internal change counter to 0. If P1 is true,
3598** then the value of the change counter is copied to the database handle
3599** change counter (returned by subsequent calls to sqlite3_changes())
3600** before it is reset. This is used by trigger programs.
3601*/
3602case OP_ResetCount: { /* no-push */
3603 if( pOp->p1 ){
3604 sqlite3VdbeSetChanges(db, p->nChange);
3605 }
3606 p->nChange = 0;
3607 break;
3608}
3609
3610/* Opcode: RowData P1 * *
3611**
3612** Push onto the stack the complete row data for cursor P1.
3613** There is no interpretation of the data. It is just copied
3614** onto the stack exactly as it is found in the database file.
3615**
3616** If the cursor is not pointing to a valid row, a NULL is pushed
3617** onto the stack.
3618*/
3619/* Opcode: RowKey P1 * *
3620**
3621** Push onto the stack the complete row key for cursor P1.
3622** There is no interpretation of the key. It is just copied
3623** onto the stack exactly as it is found in the database file.
3624**
3625** If the cursor is not pointing to a valid row, a NULL is pushed
3626** onto the stack.
3627*/
3628case OP_RowKey:
3629case OP_RowData: {
3630 int i = pOp->p1;
3631 Cursor *pC;
3632 u32 n;
3633
3634 /* Note that RowKey and RowData are really exactly the same instruction */
3635 pTos++;
3636 assert( i>=0 && i<p->nCursor );
3637 pC = p->apCsr[i];
3638 assert( pC->isTable || pOp->opcode==OP_RowKey );
3639 assert( pC->isIndex || pOp->opcode==OP_RowData );
3640 assert( pC!=0 );
3641 if( pC->nullRow ){
3642 pTos->flags = MEM_Null;
3643 }else if( pC->pCursor!=0 ){
3644 BtCursor *pCrsr = pC->pCursor;
3645 rc = sqlite3VdbeCursorMoveto(pC);
3646 if( rc ) goto abort_due_to_error;
3647 if( pC->nullRow ){
3648 pTos->flags = MEM_Null;
3649 break;
3650 }else if( pC->isIndex ){
3651 i64 n64;
3652 assert( !pC->isTable );
3653 sqlite3BtreeKeySize(pCrsr, &n64);
3654 if( n64>SQLITE_MAX_LENGTH ){
3655 goto too_big;
3656 }
3657 n = n64;
3658 }else{
3659 sqlite3BtreeDataSize(pCrsr, &n);
3660 }
3661 if( n>SQLITE_MAX_LENGTH ){
3662 goto too_big;
3663 }
3664 pTos->n = n;
3665 if( n<=NBFS ){
3666 pTos->flags = MEM_Blob | MEM_Short;
3667 pTos->z = pTos->zShort;
3668 }else{
3669 char *z = sqlite3_malloc( n );
3670 if( z==0 ) goto no_mem;
3671 pTos->flags = MEM_Blob | MEM_Dyn;
3672 pTos->xDel = 0;
3673 pTos->z = z;
3674 }
3675 if( pC->isIndex ){
3676 rc = sqlite3BtreeKey(pCrsr, 0, n, pTos->z);
3677 }else{
3678 rc = sqlite3BtreeData(pCrsr, 0, n, pTos->z);
3679 }
3680 }else if( pC->pseudoTable ){
3681 pTos->n = pC->nData;
3682 assert( pC->nData<=SQLITE_MAX_LENGTH );
3683 pTos->z = pC->pData;
3684 pTos->flags = MEM_Blob|MEM_Ephem;
3685 }else{
3686 pTos->flags = MEM_Null;
3687 }
3688 pTos->enc = SQLITE_UTF8; /* In case the blob is ever cast to text */
3689 break;
3690}
3691
3692/* Opcode: Rowid P1 * *
3693**
3694** Push onto the stack an integer which is the key of the table entry that
3695** P1 is currently point to.
3696*/
3697case OP_Rowid: {
3698 int i = pOp->p1;
3699 Cursor *pC;
3700 i64 v;
3701
3702 assert( i>=0 && i<p->nCursor );
3703 pC = p->apCsr[i];
3704 assert( pC!=0 );
3705 rc = sqlite3VdbeCursorMoveto(pC);
3706 if( rc ) goto abort_due_to_error;
3707 pTos++;
3708 if( pC->rowidIsValid ){
3709 v = pC->lastRowid;
3710 }else if( pC->pseudoTable ){
3711 v = keyToInt(pC->iKey);
3712 }else if( pC->nullRow || pC->pCursor==0 ){
3713 pTos->flags = MEM_Null;
3714 break;
3715 }else{
3716 assert( pC->pCursor!=0 );
3717 sqlite3BtreeKeySize(pC->pCursor, &v);
3718 v = keyToInt(v);
3719 }
3720 pTos->u.i = v;
3721 pTos->flags = MEM_Int;
3722 break;
3723}
3724
3725/* Opcode: NullRow P1 * *
3726**
3727** Move the cursor P1 to a null row. Any OP_Column operations
3728** that occur while the cursor is on the null row will always push
3729** a NULL onto the stack.
3730*/
3731case OP_NullRow: { /* no-push */
3732 int i = pOp->p1;
3733 Cursor *pC;
3734
3735 assert( i>=0 && i<p->nCursor );
3736 pC = p->apCsr[i];
3737 assert( pC!=0 );
3738 pC->nullRow = 1;
3739 pC->rowidIsValid = 0;
3740 break;
3741}
3742
3743/* Opcode: Last P1 P2 *
3744**
3745** The next use of the Rowid or Column or Next instruction for P1
3746** will refer to the last entry in the database table or index.
3747** If the table or index is empty and P2>0, then jump immediately to P2.
3748** If P2 is 0 or if the table or index is not empty, fall through
3749** to the following instruction.
3750*/
3751case OP_Last: { /* no-push */
3752 int i = pOp->p1;
3753 Cursor *pC;
3754 BtCursor *pCrsr;
3755
3756 assert( i>=0 && i<p->nCursor );
3757 pC = p->apCsr[i];
3758 assert( pC!=0 );
3759 if( (pCrsr = pC->pCursor)!=0 ){
3760 int res;
3761 rc = sqlite3BtreeLast(pCrsr, &res);
3762 pC->nullRow = res;
3763 pC->deferredMoveto = 0;
3764 pC->cacheStatus = CACHE_STALE;
3765 if( res && pOp->p2>0 ){
3766 pc = pOp->p2 - 1;
3767 }
3768 }else{
3769 pC->nullRow = 0;
3770 }
3771 break;
3772}
3773
3774
3775/* Opcode: Sort P1 P2 *
3776**
3777** This opcode does exactly the same thing as OP_Rewind except that
3778** it increments an undocumented global variable used for testing.
3779**
3780** Sorting is accomplished by writing records into a sorting index,
3781** then rewinding that index and playing it back from beginning to
3782** end. We use the OP_Sort opcode instead of OP_Rewind to do the
3783** rewinding so that the global variable will be incremented and
3784** regression tests can determine whether or not the optimizer is
3785** correctly optimizing out sorts.
3786*/
3787case OP_Sort: { /* no-push */
3788#ifdef SQLITE_TEST
3789 sqlite3_sort_count++;
3790 sqlite3_search_count--;
3791#endif
3792 /* Fall through into OP_Rewind */
3793}
3794/* Opcode: Rewind P1 P2 *
3795**
3796** The next use of the Rowid or Column or Next instruction for P1
3797** will refer to the first entry in the database table or index.
3798** If the table or index is empty and P2>0, then jump immediately to P2.
3799** If P2 is 0 or if the table or index is not empty, fall through
3800** to the following instruction.
3801*/
3802case OP_Rewind: { /* no-push */
3803 int i = pOp->p1;
3804 Cursor *pC;
3805 BtCursor *pCrsr;
3806 int res;
3807
3808 assert( i>=0 && i<p->nCursor );
3809 pC = p->apCsr[i];
3810 assert( pC!=0 );
3811 if( (pCrsr = pC->pCursor)!=0 ){
3812 rc = sqlite3BtreeFirst(pCrsr, &res);
3813 pC->atFirst = res==0;
3814 pC->deferredMoveto = 0;
3815 pC->cacheStatus = CACHE_STALE;
3816 }else{
3817 res = 1;
3818 }
3819 pC->nullRow = res;
3820 if( res && pOp->p2>0 ){
3821 pc = pOp->p2 - 1;
3822 }
3823 break;
3824}
3825
3826/* Opcode: Next P1 P2 *
3827**
3828** Advance cursor P1 so that it points to the next key/data pair in its
3829** table or index. If there are no more key/value pairs then fall through
3830** to the following instruction. But if the cursor advance was successful,
3831** jump immediately to P2.
3832**
3833** See also: Prev
3834*/
3835/* Opcode: Prev P1 P2 *
3836**
3837** Back up cursor P1 so that it points to the previous key/data pair in its
3838** table or index. If there is no previous key/value pairs then fall through
3839** to the following instruction. But if the cursor backup was successful,
3840** jump immediately to P2.
3841*/
3842case OP_Prev: /* no-push */
3843case OP_Next: { /* no-push */
3844 Cursor *pC;
3845 BtCursor *pCrsr;
3846
3847 CHECK_FOR_INTERRUPT;
3848 assert( pOp->p1>=0 && pOp->p1<p->nCursor );
3849 pC = p->apCsr[pOp->p1];
3850 if( pC==0 ){
3851 break; /* See ticket #2273 */
3852 }
3853 if( (pCrsr = pC->pCursor)!=0 ){
3854 int res;
3855 if( pC->nullRow ){
3856 res = 1;
3857 }else{
3858 assert( pC->deferredMoveto==0 );
3859 rc = pOp->opcode==OP_Next ? sqlite3BtreeNext(pCrsr, &res) :
3860 sqlite3BtreePrevious(pCrsr, &res);
3861 pC->nullRow = res;
3862 pC->cacheStatus = CACHE_STALE;
3863 }
3864 if( res==0 ){
3865 pc = pOp->p2 - 1;
3866#ifdef SQLITE_TEST
3867 sqlite3_search_count++;
3868#endif
3869 }
3870 }else{
3871 pC->nullRow = 1;
3872 }
3873 pC->rowidIsValid = 0;
3874 break;
3875}
3876
3877/* Opcode: IdxInsert P1 P2 *
3878**
3879** The top of the stack holds a SQL index key made using either the
3880** MakeIdxRec or MakeRecord instructions. This opcode writes that key
3881** into the index P1. Data for the entry is nil.
3882**
3883** P2 is a flag that provides a hint to the b-tree layer that this
3884** insert is likely to be an append.
3885**
3886** This instruction only works for indices. The equivalent instruction
3887** for tables is OP_Insert.
3888*/
3889case OP_IdxInsert: { /* no-push */
3890 int i = pOp->p1;
3891 Cursor *pC;
3892 BtCursor *pCrsr;
3893 assert( pTos>=p->aStack );
3894 assert( i>=0 && i<p->nCursor );
3895 assert( p->apCsr[i]!=0 );
3896 assert( pTos->flags & MEM_Blob );
3897 if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
3898 assert( pC->isTable==0 );
3899 rc = ExpandBlob(pTos);
3900 if( rc==SQLITE_OK ){
3901 int nKey = pTos->n;
3902 const char *zKey = pTos->z;
3903 rc = sqlite3BtreeInsert(pCrsr, zKey, nKey, "", 0, 0, pOp->p2);
3904 assert( pC->deferredMoveto==0 );
3905 pC->cacheStatus = CACHE_STALE;
3906 }
3907 }
3908 Release(pTos);
3909 pTos--;
3910 break;
3911}
3912
3913/* Opcode: IdxDelete P1 * *
3914**
3915** The top of the stack is an index key built using the either the
3916** MakeIdxRec or MakeRecord opcodes.
3917** This opcode removes that entry from the index.
3918*/
3919case OP_IdxDelete: { /* no-push */
3920 int i = pOp->p1;
3921 Cursor *pC;
3922 BtCursor *pCrsr;
3923 assert( pTos>=p->aStack );
3924 assert( pTos->flags & MEM_Blob );
3925 assert( i>=0 && i<p->nCursor );
3926 assert( p->apCsr[i]!=0 );
3927 if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
3928 int res;
3929 rc = sqlite3BtreeMoveto(pCrsr, pTos->z, pTos->n, 0, &res);
3930 if( rc==SQLITE_OK && res==0 ){
3931 rc = sqlite3BtreeDelete(pCrsr);
3932 }
3933 assert( pC->deferredMoveto==0 );
3934 pC->cacheStatus = CACHE_STALE;
3935 }
3936 Release(pTos);
3937 pTos--;
3938 break;
3939}
3940
3941/* Opcode: IdxRowid P1 * *
3942**
3943** Push onto the stack an integer which is the last entry in the record at
3944** the end of the index key pointed to by cursor P1. This integer should be
3945** the rowid of the table entry to which this index entry points.
3946**
3947** See also: Rowid, MakeIdxRec.
3948*/
3949case OP_IdxRowid: {
3950 int i = pOp->p1;
3951 BtCursor *pCrsr;
3952 Cursor *pC;
3953
3954 assert( i>=0 && i<p->nCursor );
3955 assert( p->apCsr[i]!=0 );
3956 pTos++;
3957 pTos->flags = MEM_Null;
3958 if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
3959 i64 rowid;
3960
3961 assert( pC->deferredMoveto==0 );
3962 assert( pC->isTable==0 );
3963 if( pC->nullRow ){
3964 pTos->flags = MEM_Null;
3965 }else{
3966 rc = sqlite3VdbeIdxRowid(pCrsr, &rowid);
3967 if( rc!=SQLITE_OK ){
3968 goto abort_due_to_error;
3969 }
3970 pTos->flags = MEM_Int;
3971 pTos->u.i = rowid;
3972 }
3973 }
3974 break;
3975}
3976
3977/* Opcode: IdxGT P1 P2 *
3978**
3979** The top of the stack is an index entry that omits the ROWID. Compare
3980** the top of stack against the index that P1 is currently pointing to.
3981** Ignore the ROWID on the P1 index.
3982**
3983** The top of the stack might have fewer columns that P1.
3984**
3985** If the P1 index entry is greater than the top of the stack
3986** then jump to P2. Otherwise fall through to the next instruction.
3987** In either case, the stack is popped once.
3988*/
3989/* Opcode: IdxGE P1 P2 P3
3990**
3991** The top of the stack is an index entry that omits the ROWID. Compare
3992** the top of stack against the index that P1 is currently pointing to.
3993** Ignore the ROWID on the P1 index.
3994**
3995** If the P1 index entry is greater than or equal to the top of the stack
3996** then jump to P2. Otherwise fall through to the next instruction.
3997** In either case, the stack is popped once.
3998**
3999** If P3 is the "+" string (or any other non-NULL string) then the
4000** index taken from the top of the stack is temporarily increased by
4001** an epsilon prior to the comparison. This make the opcode work
4002** like IdxGT except that if the key from the stack is a prefix of
4003** the key in the cursor, the result is false whereas it would be
4004** true with IdxGT.
4005*/
4006/* Opcode: IdxLT P1 P2 P3
4007**
4008** The top of the stack is an index entry that omits the ROWID. Compare
4009** the top of stack against the index that P1 is currently pointing to.
4010** Ignore the ROWID on the P1 index.
4011**
4012** If the P1 index entry is less than the top of the stack
4013** then jump to P2. Otherwise fall through to the next instruction.
4014** In either case, the stack is popped once.
4015**
4016** If P3 is the "+" string (or any other non-NULL string) then the
4017** index taken from the top of the stack is temporarily increased by
4018** an epsilon prior to the comparison. This makes the opcode work
4019** like IdxLE.
4020*/
4021case OP_IdxLT: /* no-push */
4022case OP_IdxGT: /* no-push */
4023case OP_IdxGE: { /* no-push */
4024 int i= pOp->p1;
4025 Cursor *pC;
4026
4027 assert( i>=0 && i<p->nCursor );
4028 assert( p->apCsr[i]!=0 );
4029 assert( pTos>=p->aStack );
4030 if( (pC = p->apCsr[i])->pCursor!=0 ){
4031 int res;
4032
4033 assert( pTos->flags & MEM_Blob ); /* Created using OP_MakeRecord */
4034 assert( pC->deferredMoveto==0 );
4035 ExpandBlob(pTos);
4036 *pC->pIncrKey = pOp->p3!=0;
4037 assert( pOp->p3==0 || pOp->opcode!=OP_IdxGT );
4038 rc = sqlite3VdbeIdxKeyCompare(pC, pTos->n, (u8*)pTos->z, &res);
4039 *pC->pIncrKey = 0;
4040 if( rc!=SQLITE_OK ){
4041 break;
4042 }
4043 if( pOp->opcode==OP_IdxLT ){
4044 res = -res;
4045 }else if( pOp->opcode==OP_IdxGE ){
4046 res++;
4047 }
4048 if( res>0 ){
4049 pc = pOp->p2 - 1 ;
4050 }
4051 }
4052 Release(pTos);
4053 pTos--;
4054 break;
4055}
4056
4057/* Opcode: Destroy P1 P2 *
4058**
4059** Delete an entire database table or index whose root page in the database
4060** file is given by P1.
4061**
4062** The table being destroyed is in the main database file if P2==0. If
4063** P2==1 then the table to be clear is in the auxiliary database file
4064** that is used to store tables create using CREATE TEMPORARY TABLE.
4065**
4066** If AUTOVACUUM is enabled then it is possible that another root page
4067** might be moved into the newly deleted root page in order to keep all
4068** root pages contiguous at the beginning of the database. The former
4069** value of the root page that moved - its value before the move occurred -
4070** is pushed onto the stack. If no page movement was required (because
4071** the table being dropped was already the last one in the database) then
4072** a zero is pushed onto the stack. If AUTOVACUUM is disabled
4073** then a zero is pushed onto the stack.
4074**
4075** See also: Clear
4076*/
4077case OP_Destroy: {
4078 int iMoved;
4079 int iCnt;
4080#ifndef SQLITE_OMIT_VIRTUALTABLE
4081 Vdbe *pVdbe;
4082 iCnt = 0;
4083 for(pVdbe=db->pVdbe; pVdbe; pVdbe=pVdbe->pNext){
4084 if( pVdbe->magic==VDBE_MAGIC_RUN && pVdbe->inVtabMethod<2 && pVdbe->pc>=0 ){
4085 iCnt++;
4086 }
4087 }
4088#else
4089 iCnt = db->activeVdbeCnt;
4090#endif
4091 if( iCnt>1 ){
4092 rc = SQLITE_LOCKED;
4093 }else{
4094 assert( iCnt==1 );
4095 assert( (p->btreeMask & (1<<pOp->p2))!=0 );
4096 rc = sqlite3BtreeDropTable(db->aDb[pOp->p2].pBt, pOp->p1, &iMoved);
4097 pTos++;
4098 pTos->flags = MEM_Int;
4099 pTos->u.i = iMoved;
4100#ifndef SQLITE_OMIT_AUTOVACUUM
4101 if( rc==SQLITE_OK && iMoved!=0 ){
4102 sqlite3RootPageMoved(&db->aDb[pOp->p2], iMoved, pOp->p1);
4103 }
4104#endif
4105 }
4106 break;
4107}
4108
4109/* Opcode: Clear P1 P2 *
4110**
4111** Delete all contents of the database table or index whose root page
4112** in the database file is given by P1. But, unlike Destroy, do not
4113** remove the table or index from the database file.
4114**
4115** The table being clear is in the main database file if P2==0. If
4116** P2==1 then the table to be clear is in the auxiliary database file
4117** that is used to store tables create using CREATE TEMPORARY TABLE.
4118**
4119** See also: Destroy
4120*/
4121case OP_Clear: { /* no-push */
4122
4123 /* For consistency with the way other features of SQLite operate
4124 ** with a truncate, we will also skip the update callback.
4125 */
4126#if 0
4127 Btree *pBt = db->aDb[pOp->p2].pBt;
4128 if( db->xUpdateCallback && pOp->p3 ){
4129 const char *zDb = db->aDb[pOp->p2].zName;
4130 const char *zTbl = pOp->p3;
4131 BtCursor *pCur = 0;
4132 int fin = 0;
4133
4134 rc = sqlite3BtreeCursor(pBt, pOp->p1, 0, 0, 0, &pCur);
4135 if( rc!=SQLITE_OK ){
4136 goto abort_due_to_error;
4137 }
4138 for(
4139 rc=sqlite3BtreeFirst(pCur, &fin);
4140 rc==SQLITE_OK && !fin;
4141 rc=sqlite3BtreeNext(pCur, &fin)
4142 ){
4143 i64 iKey;
4144 rc = sqlite3BtreeKeySize(pCur, &iKey);
4145 if( rc ){
4146 break;
4147 }
4148 iKey = keyToInt(iKey);
4149 db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, zTbl, iKey);
4150 }
4151 sqlite3BtreeCloseCursor(pCur);
4152 if( rc!=SQLITE_OK ){
4153 goto abort_due_to_error;
4154 }
4155 }
4156#endif
4157 assert( (p->btreeMask & (1<<pOp->p2))!=0 );
4158 rc = sqlite3BtreeClearTable(db->aDb[pOp->p2].pBt, pOp->p1);
4159 break;
4160}
4161
4162/* Opcode: CreateTable P1 * *
4163**
4164** Allocate a new table in the main database file if P2==0 or in the
4165** auxiliary database file if P2==1. Push the page number
4166** for the root page of the new table onto the stack.
4167**
4168** The difference between a table and an index is this: A table must
4169** have a 4-byte integer key and can have arbitrary data. An index
4170** has an arbitrary key but no data.
4171**
4172** See also: CreateIndex
4173*/
4174/* Opcode: CreateIndex P1 * *
4175**
4176** Allocate a new index in the main database file if P2==0 or in the
4177** auxiliary database file if P2==1. Push the page number of the
4178** root page of the new index onto the stack.
4179**
4180** See documentation on OP_CreateTable for additional information.
4181*/
4182case OP_CreateIndex:
4183case OP_CreateTable: {
4184 int pgno;
4185 int flags;
4186 Db *pDb;
4187 assert( pOp->p1>=0 && pOp->p1<db->nDb );
4188 assert( (p->btreeMask & (1<<pOp->p1))!=0 );
4189 pDb = &db->aDb[pOp->p1];
4190 assert( pDb->pBt!=0 );
4191 if( pOp->opcode==OP_CreateTable ){
4192 /* flags = BTREE_INTKEY; */
4193 flags = BTREE_LEAFDATA|BTREE_INTKEY;
4194 }else{
4195 flags = BTREE_ZERODATA;
4196 }
4197 rc = sqlite3BtreeCreateTable(pDb->pBt, &pgno, flags);
4198 pTos++;
4199 if( rc==SQLITE_OK ){
4200 pTos->u.i = pgno;
4201 pTos->flags = MEM_Int;
4202 }else{
4203 pTos->flags = MEM_Null;
4204 }
4205 break;
4206}
4207
4208/* Opcode: ParseSchema P1 P2 P3
4209**
4210** Read and parse all entries from the SQLITE_MASTER table of database P1
4211** that match the WHERE clause P3. P2 is the "force" flag. Always do
4212** the parsing if P2 is true. If P2 is false, then this routine is a
4213** no-op if the schema is not currently loaded. In other words, if P2
4214** is false, the SQLITE_MASTER table is only parsed if the rest of the
4215** schema is already loaded into the symbol table.
4216**
4217** This opcode invokes the parser to create a new virtual machine,
4218** then runs the new virtual machine. It is thus a reentrant opcode.
4219*/
4220case OP_ParseSchema: { /* no-push */
4221 char *zSql;
4222 int iDb = pOp->p1;
4223 const char *zMaster;
4224 InitData initData;
4225
4226 assert( iDb>=0 && iDb<db->nDb );
4227 if( !pOp->p2 && !DbHasProperty(db, iDb, DB_SchemaLoaded) ){
4228 break;
4229 }
4230 zMaster = SCHEMA_TABLE(iDb);
4231 initData.db = db;
4232 initData.iDb = pOp->p1;
4233 initData.pzErrMsg = &p->zErrMsg;
4234 zSql = sqlite3MPrintf(db,
4235 "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s",
4236 db->aDb[iDb].zName, zMaster, pOp->p3);
4237 if( zSql==0 ) goto no_mem;
4238 sqlite3SafetyOff(db);
4239 assert( db->init.busy==0 );
4240 db->init.busy = 1;
4241 assert( !db->mallocFailed );
4242 rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
4243 if( rc==SQLITE_ABORT ) rc = initData.rc;
4244 sqlite3_free(zSql);
4245 db->init.busy = 0;
4246 sqlite3SafetyOn(db);
4247 if( rc==SQLITE_NOMEM ){
4248 goto no_mem;
4249 }
4250 break;
4251}
4252
4253#if !defined(SQLITE_OMIT_ANALYZE) && !defined(SQLITE_OMIT_PARSER)
4254/* Opcode: LoadAnalysis P1 * *
4255**
4256** Read the sqlite_stat1 table for database P1 and load the content
4257** of that table into the internal index hash table. This will cause
4258** the analysis to be used when preparing all subsequent queries.
4259*/
4260case OP_LoadAnalysis: { /* no-push */
4261 int iDb = pOp->p1;
4262 assert( iDb>=0 && iDb<db->nDb );
4263 rc = sqlite3AnalysisLoad(db, iDb);
4264 break;
4265}
4266#endif /* !defined(SQLITE_OMIT_ANALYZE) && !defined(SQLITE_OMIT_PARSER) */
4267
4268/* Opcode: DropTable P1 * P3
4269**
4270** Remove the internal (in-memory) data structures that describe
4271** the table named P3 in database P1. This is called after a table
4272** is dropped in order to keep the internal representation of the
4273** schema consistent with what is on disk.
4274*/
4275case OP_DropTable: { /* no-push */
4276 sqlite3UnlinkAndDeleteTable(db, pOp->p1, pOp->p3);
4277 break;
4278}
4279
4280/* Opcode: DropIndex P1 * P3
4281**
4282** Remove the internal (in-memory) data structures that describe
4283** the index named P3 in database P1. This is called after an index
4284** is dropped in order to keep the internal representation of the
4285** schema consistent with what is on disk.
4286*/
4287case OP_DropIndex: { /* no-push */
4288 sqlite3UnlinkAndDeleteIndex(db, pOp->p1, pOp->p3);
4289 break;
4290}
4291
4292/* Opcode: DropTrigger P1 * P3
4293**
4294** Remove the internal (in-memory) data structures that describe
4295** the trigger named P3 in database P1. This is called after a trigger
4296** is dropped in order to keep the internal representation of the
4297** schema consistent with what is on disk.
4298*/
4299case OP_DropTrigger: { /* no-push */
4300 sqlite3UnlinkAndDeleteTrigger(db, pOp->p1, pOp->p3);
4301 break;
4302}
4303
4304
4305#ifndef SQLITE_OMIT_INTEGRITY_CHECK
4306/* Opcode: IntegrityCk P1 P2 *
4307**
4308** Do an analysis of the currently open database. Push onto the
4309** stack the text of an error message describing any problems.
4310** If no problems are found, push a NULL onto the stack.
4311**
4312** P1 is the address of a memory cell that contains the maximum
4313** number of allowed errors. At most mem[P1] errors will be reported.
4314** In other words, the analysis stops as soon as mem[P1] errors are
4315** seen. Mem[P1] is updated with the number of errors remaining.
4316**
4317** The root page numbers of all tables in the database are integer
4318** values on the stack. This opcode pulls as many integers as it
4319** can off of the stack and uses those numbers as the root pages.
4320**
4321** If P2 is not zero, the check is done on the auxiliary database
4322** file, not the main database file.
4323**
4324** This opcode is used to implement the integrity_check pragma.
4325*/
4326case OP_IntegrityCk: {
4327 int nRoot;
4328 int *aRoot;
4329 int j;
4330 int nErr;
4331 char *z;
4332 Mem *pnErr;
4333
4334 for(nRoot=0; &pTos[-nRoot]>=p->aStack; nRoot++){
4335 if( (pTos[-nRoot].flags & MEM_Int)==0 ) break;
4336 }
4337 assert( nRoot>0 );
4338 aRoot = sqlite3_malloc( sizeof(int)*(nRoot+1) );
4339 if( aRoot==0 ) goto no_mem;
4340 j = pOp->p1;
4341 assert( j>=0 && j<p->nMem );
4342 pnErr = &p->aMem[j];
4343 assert( (pnErr->flags & MEM_Int)!=0 );
4344 for(j=0; j<nRoot; j++){
4345 aRoot[j] = (pTos-j)->u.i;
4346 }
4347 aRoot[j] = 0;
4348 popStack(&pTos, nRoot);
4349 pTos++;
4350 assert( pOp->p2>=0 && pOp->p2<db->nDb );
4351 assert( (p->btreeMask & (1<<pOp->p2))!=0 );
4352 z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p2].pBt, aRoot, nRoot,
4353 pnErr->u.i, &nErr);
4354 pnErr->u.i -= nErr;
4355 if( nErr==0 ){
4356 assert( z==0 );
4357 pTos->flags = MEM_Null;
4358 }else{
4359 pTos->z = z;
4360 pTos->n = strlen(z);
4361 pTos->flags = MEM_Str | MEM_Dyn | MEM_Term;
4362 pTos->xDel = 0;
4363 }
4364 pTos->enc = SQLITE_UTF8;
4365 sqlite3VdbeChangeEncoding(pTos, encoding);
4366 sqlite3_free(aRoot);
4367 break;
4368}
4369#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
4370
4371/* Opcode: FifoWrite * * *
4372**
4373** Write the integer on the top of the stack
4374** into the Fifo.
4375*/
4376case OP_FifoWrite: { /* no-push */
4377 assert( pTos>=p->aStack );
4378 sqlite3VdbeMemIntegerify(pTos);
4379 if( sqlite3VdbeFifoPush(&p->sFifo, pTos->u.i)==SQLITE_NOMEM ){
4380 goto no_mem;
4381 }
4382 assert( (pTos->flags & MEM_Dyn)==0 );
4383 pTos--;
4384 break;
4385}
4386
4387/* Opcode: FifoRead * P2 *
4388**
4389** Attempt to read a single integer from the Fifo
4390** and push it onto the stack. If the Fifo is empty
4391** push nothing but instead jump to P2.
4392*/
4393case OP_FifoRead: {
4394 i64 v;
4395 CHECK_FOR_INTERRUPT;
4396 if( sqlite3VdbeFifoPop(&p->sFifo, &v)==SQLITE_DONE ){
4397 pc = pOp->p2 - 1;
4398 }else{
4399 pTos++;
4400 pTos->u.i = v;
4401 pTos->flags = MEM_Int;
4402 }
4403 break;
4404}
4405
4406#ifndef SQLITE_OMIT_TRIGGER
4407/* Opcode: ContextPush * * *
4408**
4409** Save the current Vdbe context such that it can be restored by a ContextPop
4410** opcode. The context stores the last insert row id, the last statement change
4411** count, and the current statement change count.
4412*/
4413case OP_ContextPush: { /* no-push */
4414 int i = p->contextStackTop++;
4415 Context *pContext;
4416
4417 assert( i>=0 );
4418 /* FIX ME: This should be allocated as part of the vdbe at compile-time */
4419 if( i>=p->contextStackDepth ){
4420 p->contextStackDepth = i+1;
4421 p->contextStack = sqlite3DbReallocOrFree(db, p->contextStack,
4422 sizeof(Context)*(i+1));
4423 if( p->contextStack==0 ) goto no_mem;
4424 }
4425 pContext = &p->contextStack[i];
4426 pContext->lastRowid = db->lastRowid;
4427 pContext->nChange = p->nChange;
4428 pContext->sFifo = p->sFifo;
4429 sqlite3VdbeFifoInit(&p->sFifo);
4430 break;
4431}
4432
4433/* Opcode: ContextPop * * *
4434**
4435** Restore the Vdbe context to the state it was in when contextPush was last
4436** executed. The context stores the last insert row id, the last statement
4437** change count, and the current statement change count.
4438*/
4439case OP_ContextPop: { /* no-push */
4440 Context *pContext = &p->contextStack[--p->contextStackTop];
4441 assert( p->contextStackTop>=0 );
4442 db->lastRowid = pContext->lastRowid;
4443 p->nChange = pContext->nChange;
4444 sqlite3VdbeFifoClear(&p->sFifo);
4445 p->sFifo = pContext->sFifo;
4446 break;
4447}
4448#endif /* #ifndef SQLITE_OMIT_TRIGGER */
4449
4450/* Opcode: MemStore P1 P2 *
4451**
4452** Write the top of the stack into memory location P1.
4453** P1 should be a small integer since space is allocated
4454** for all memory locations between 0 and P1 inclusive.
4455**
4456** After the data is stored in the memory location, the
4457** stack is popped once if P2 is 1. If P2 is zero, then
4458** the original data remains on the stack.
4459*/
4460case OP_MemStore: { /* no-push */
4461 assert( pTos>=p->aStack );
4462 assert( pOp->p1>=0 && pOp->p1<p->nMem );
4463 rc = sqlite3VdbeMemMove(&p->aMem[pOp->p1], pTos);
4464 pTos--;
4465
4466 /* If P2 is 0 then fall thru to the next opcode, OP_MemLoad, that will
4467 ** restore the top of the stack to its original value.
4468 */
4469 if( pOp->p2 ){
4470 break;
4471 }
4472}
4473/* Opcode: MemLoad P1 * *
4474**
4475** Push a copy of the value in memory location P1 onto the stack.
4476**
4477** If the value is a string, then the value pushed is a pointer to
4478** the string that is stored in the memory location. If the memory
4479** location is subsequently changed (using OP_MemStore) then the
4480** value pushed onto the stack will change too.
4481*/
4482case OP_MemLoad: {
4483 int i = pOp->p1;
4484 assert( i>=0 && i<p->nMem );
4485 pTos++;
4486 sqlite3VdbeMemShallowCopy(pTos, &p->aMem[i], MEM_Ephem);
4487 break;
4488}
4489
4490#ifndef SQLITE_OMIT_AUTOINCREMENT
4491/* Opcode: MemMax P1 * *
4492**
4493** Set the value of memory cell P1 to the maximum of its current value
4494** and the value on the top of the stack. The stack is unchanged.
4495**
4496** This instruction throws an error if the memory cell is not initially
4497** an integer.
4498*/
4499case OP_MemMax: { /* no-push */
4500 int i = pOp->p1;
4501 Mem *pMem;
4502 assert( pTos>=p->aStack );
4503 assert( i>=0 && i<p->nMem );
4504 pMem = &p->aMem[i];
4505 sqlite3VdbeMemIntegerify(pMem);
4506 sqlite3VdbeMemIntegerify(pTos);
4507 if( pMem->u.i<pTos->u.i){
4508 pMem->u.i = pTos->u.i;
4509 }
4510 break;
4511}
4512#endif /* SQLITE_OMIT_AUTOINCREMENT */
4513
4514/* Opcode: MemIncr P1 P2 *
4515**
4516** Increment the integer valued memory cell P2 by the value in P1.
4517**
4518** It is illegal to use this instruction on a memory cell that does
4519** not contain an integer. An assertion fault will result if you try.
4520*/
4521case OP_MemIncr: { /* no-push */
4522 int i = pOp->p2;
4523 Mem *pMem;
4524 assert( i>=0 && i<p->nMem );
4525 pMem = &p->aMem[i];
4526 assert( pMem->flags==MEM_Int );
4527 pMem->u.i += pOp->p1;
4528 break;
4529}
4530
4531/* Opcode: IfMemPos P1 P2 *
4532**
4533** If the value of memory cell P1 is 1 or greater, jump to P2.
4534**
4535** It is illegal to use this instruction on a memory cell that does
4536** not contain an integer. An assertion fault will result if you try.
4537*/
4538case OP_IfMemPos: { /* no-push */
4539 int i = pOp->p1;
4540 Mem *pMem;
4541 assert( i>=0 && i<p->nMem );
4542 pMem = &p->aMem[i];
4543 assert( pMem->flags==MEM_Int );
4544 if( pMem->u.i>0 ){
4545 pc = pOp->p2 - 1;
4546 }
4547 break;
4548}
4549
4550/* Opcode: IfMemNeg P1 P2 *
4551**
4552** If the value of memory cell P1 is less than zero, jump to P2.
4553**
4554** It is illegal to use this instruction on a memory cell that does
4555** not contain an integer. An assertion fault will result if you try.
4556*/
4557case OP_IfMemNeg: { /* no-push */
4558 int i = pOp->p1;
4559 Mem *pMem;
4560 assert( i>=0 && i<p->nMem );
4561 pMem = &p->aMem[i];
4562 assert( pMem->flags==MEM_Int );
4563 if( pMem->u.i<0 ){
4564 pc = pOp->p2 - 1;
4565 }
4566 break;
4567}
4568
4569/* Opcode: IfMemZero P1 P2 *
4570**
4571** If the value of memory cell P1 is exactly 0, jump to P2.
4572**
4573** It is illegal to use this instruction on a memory cell that does
4574** not contain an integer. An assertion fault will result if you try.
4575*/
4576case OP_IfMemZero: { /* no-push */
4577 int i = pOp->p1;
4578 Mem *pMem;
4579 assert( i>=0 && i<p->nMem );
4580 pMem = &p->aMem[i];
4581 assert( pMem->flags==MEM_Int );
4582 if( pMem->u.i==0 ){
4583 pc = pOp->p2 - 1;
4584 }
4585 break;
4586}
4587
4588/* Opcode: MemNull P1 * *
4589**
4590** Store a NULL in memory cell P1
4591*/
4592case OP_MemNull: {
4593 assert( pOp->p1>=0 && pOp->p1<p->nMem );
4594 sqlite3VdbeMemSetNull(&p->aMem[pOp->p1]);
4595 break;
4596}
4597
4598/* Opcode: MemInt P1 P2 *
4599**
4600** Store the integer value P1 in memory cell P2.
4601*/
4602case OP_MemInt: {
4603 assert( pOp->p2>=0 && pOp->p2<p->nMem );
4604 sqlite3VdbeMemSetInt64(&p->aMem[pOp->p2], pOp->p1);
4605 break;
4606}
4607
4608/* Opcode: MemMove P1 P2 *
4609**
4610** Move the content of memory cell P2 over to memory cell P1.
4611** Any prior content of P1 is erased. Memory cell P2 is left
4612** containing a NULL.
4613*/
4614case OP_MemMove: {
4615 assert( pOp->p1>=0 && pOp->p1<p->nMem );
4616 assert( pOp->p2>=0 && pOp->p2<p->nMem );
4617 rc = sqlite3VdbeMemMove(&p->aMem[pOp->p1], &p->aMem[pOp->p2]);
4618 break;
4619}
4620
4621/* Opcode: AggStep P1 P2 P3
4622**
4623** Execute the step function for an aggregate. The
4624** function has P2 arguments. P3 is a pointer to the FuncDef
4625** structure that specifies the function. Use memory location
4626** P1 as the accumulator.
4627**
4628** The P2 arguments are popped from the stack.
4629*/
4630case OP_AggStep: { /* no-push */
4631 int n = pOp->p2;
4632 int i;
4633 Mem *pMem, *pRec;
4634 sqlite3_context ctx;
4635 sqlite3_value **apVal;
4636
4637 assert( n>=0 );
4638 pRec = &pTos[1-n];
4639 assert( pRec>=p->aStack );
4640 apVal = p->apArg;
4641 assert( apVal || n==0 );
4642 for(i=0; i<n; i++, pRec++){
4643 apVal[i] = pRec;
4644 storeTypeInfo(pRec, encoding);
4645 }
4646 ctx.pFunc = (FuncDef*)pOp->p3;
4647 assert( pOp->p1>=0 && pOp->p1<p->nMem );
4648 ctx.pMem = pMem = &p->aMem[pOp->p1];
4649 pMem->n++;
4650 ctx.s.flags = MEM_Null;
4651 ctx.s.z = 0;
4652 ctx.s.xDel = 0;
4653 ctx.s.db = db;
4654 ctx.isError = 0;
4655 ctx.pColl = 0;
4656 if( ctx.pFunc->needCollSeq ){
4657 assert( pOp>p->aOp );
4658 assert( pOp[-1].p3type==P3_COLLSEQ );
4659 assert( pOp[-1].opcode==OP_CollSeq );
4660 ctx.pColl = (CollSeq *)pOp[-1].p3;
4661 }
4662 (ctx.pFunc->xStep)(&ctx, n, apVal);
4663 popStack(&pTos, n);
4664 if( ctx.isError ){
4665 sqlite3SetString(&p->zErrMsg, sqlite3_value_text(&ctx.s), (char*)0);
4666 rc = SQLITE_ERROR;
4667 }
4668 sqlite3VdbeMemRelease(&ctx.s);
4669 break;
4670}
4671
4672/* Opcode: AggFinal P1 P2 P3
4673**
4674** Execute the finalizer function for an aggregate. P1 is
4675** the memory location that is the accumulator for the aggregate.
4676**
4677** P2 is the number of arguments that the step function takes and
4678** P3 is a pointer to the FuncDef for this function. The P2
4679** argument is not used by this opcode. It is only there to disambiguate
4680** functions that can take varying numbers of arguments. The
4681** P3 argument is only needed for the degenerate case where
4682** the step function was not previously called.
4683*/
4684case OP_AggFinal: { /* no-push */
4685 Mem *pMem;
4686 assert( pOp->p1>=0 && pOp->p1<p->nMem );
4687 pMem = &p->aMem[pOp->p1];
4688 assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
4689 rc = sqlite3VdbeMemFinalize(pMem, (FuncDef*)pOp->p3);
4690 if( rc==SQLITE_ERROR ){
4691 sqlite3SetString(&p->zErrMsg, sqlite3_value_text(pMem), (char*)0);
4692 }
4693 if( sqlite3VdbeMemTooBig(pMem) ){
4694 goto too_big;
4695 }
4696 break;
4697}
4698
4699
4700#if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
4701/* Opcode: Vacuum * * *
4702**
4703** Vacuum the entire database. This opcode will cause other virtual
4704** machines to be created and run. It may not be called from within
4705** a transaction.
4706*/
4707case OP_Vacuum: { /* no-push */
4708 if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
4709 rc = sqlite3RunVacuum(&p->zErrMsg, db);
4710 if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
4711 break;
4712}
4713#endif
4714
4715#if !defined(SQLITE_OMIT_AUTOVACUUM)
4716/* Opcode: IncrVacuum P1 P2 *
4717**
4718** Perform a single step of the incremental vacuum procedure on
4719** the P1 database. If the vacuum has finished, jump to instruction
4720** P2. Otherwise, fall through to the next instruction.
4721*/
4722case OP_IncrVacuum: { /* no-push */
4723 Btree *pBt;
4724
4725 assert( pOp->p1>=0 && pOp->p1<db->nDb );
4726 assert( (p->btreeMask & (1<<pOp->p1))!=0 );
4727 pBt = db->aDb[pOp->p1].pBt;
4728 rc = sqlite3BtreeIncrVacuum(pBt);
4729 if( rc==SQLITE_DONE ){
4730 pc = pOp->p2 - 1;
4731 rc = SQLITE_OK;
4732 }
4733 break;
4734}
4735#endif
4736
4737/* Opcode: Expire P1 * *
4738**
4739** Cause precompiled statements to become expired. An expired statement
4740** fails with an error code of SQLITE_SCHEMA if it is ever executed
4741** (via sqlite3_step()).
4742**
4743** If P1 is 0, then all SQL statements become expired. If P1 is non-zero,
4744** then only the currently executing statement is affected.
4745*/
4746case OP_Expire: { /* no-push */
4747 if( !pOp->p1 ){
4748 sqlite3ExpirePreparedStatements(db);
4749 }else{
4750 p->expired = 1;
4751 }
4752 break;
4753}
4754
4755#ifndef SQLITE_OMIT_SHARED_CACHE
4756/* Opcode: TableLock P1 P2 P3
4757**
4758** Obtain a lock on a particular table. This instruction is only used when
4759** the shared-cache feature is enabled.
4760**
4761** If P1 is not negative, then it is the index of the database
4762** in sqlite3.aDb[] and a read-lock is required. If P1 is negative, a
4763** write-lock is required. In this case the index of the database is the
4764** absolute value of P1 minus one (iDb = abs(P1) - 1;) and a write-lock is
4765** required.
4766**
4767** P2 contains the root-page of the table to lock.
4768**
4769** P3 contains a pointer to the name of the table being locked. This is only
4770** used to generate an error message if the lock cannot be obtained.
4771*/
4772case OP_TableLock: { /* no-push */
4773 int p1 = pOp->p1;
4774 u8 isWriteLock = (p1<0);
4775 if( isWriteLock ){
4776 p1 = (-1*p1)-1;
4777 }
4778 assert( p1>=0 && p1<db->nDb );
4779 assert( (p->btreeMask & (1<<p1))!=0 );
4780 rc = sqlite3BtreeLockTable(db->aDb[p1].pBt, pOp->p2, isWriteLock);
4781 if( rc==SQLITE_LOCKED ){
4782 const char *z = (const char *)pOp->p3;
4783 sqlite3SetString(&p->zErrMsg, "database table is locked: ", z, (char*)0);
4784 }
4785 break;
4786}
4787#endif /* SQLITE_OMIT_SHARED_CACHE */
4788
4789#ifndef SQLITE_OMIT_VIRTUALTABLE
4790/* Opcode: VBegin * * P3
4791**
4792** P3 a pointer to an sqlite3_vtab structure. Call the xBegin method
4793** for that table.
4794*/
4795case OP_VBegin: { /* no-push */
4796 rc = sqlite3VtabBegin(db, (sqlite3_vtab *)pOp->p3);
4797 break;
4798}
4799#endif /* SQLITE_OMIT_VIRTUALTABLE */
4800
4801#ifndef SQLITE_OMIT_VIRTUALTABLE
4802/* Opcode: VCreate P1 * P3
4803**
4804** P3 is the name of a virtual table in database P1. Call the xCreate method
4805** for that table.
4806*/
4807case OP_VCreate: { /* no-push */
4808 rc = sqlite3VtabCallCreate(db, pOp->p1, pOp->p3, &p->zErrMsg);
4809 break;
4810}
4811#endif /* SQLITE_OMIT_VIRTUALTABLE */
4812
4813#ifndef SQLITE_OMIT_VIRTUALTABLE
4814/* Opcode: VDestroy P1 * P3
4815**
4816** P3 is the name of a virtual table in database P1. Call the xDestroy method
4817** of that table.
4818*/
4819case OP_VDestroy: { /* no-push */
4820 p->inVtabMethod = 2;
4821 rc = sqlite3VtabCallDestroy(db, pOp->p1, pOp->p3);
4822 p->inVtabMethod = 0;
4823 break;
4824}
4825#endif /* SQLITE_OMIT_VIRTUALTABLE */
4826
4827#ifndef SQLITE_OMIT_VIRTUALTABLE
4828/* Opcode: VOpen P1 * P3
4829**
4830** P3 is a pointer to a virtual table object, an sqlite3_vtab structure.
4831** P1 is a cursor number. This opcode opens a cursor to the virtual
4832** table and stores that cursor in P1.
4833*/
4834case OP_VOpen: { /* no-push */
4835 Cursor *pCur = 0;
4836 sqlite3_vtab_cursor *pVtabCursor = 0;
4837
4838 sqlite3_vtab *pVtab = (sqlite3_vtab *)(pOp->p3);
4839 sqlite3_module *pModule = (sqlite3_module *)pVtab->pModule;
4840
4841 assert(pVtab && pModule);
4842 if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
4843 rc = pModule->xOpen(pVtab, &pVtabCursor);
4844 if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
4845 if( SQLITE_OK==rc ){
4846 /* Initialise sqlite3_vtab_cursor base class */
4847 pVtabCursor->pVtab = pVtab;
4848
4849 /* Initialise vdbe cursor object */
4850 pCur = allocateCursor(p, pOp->p1, -1);
4851 if( pCur ){
4852 pCur->pVtabCursor = pVtabCursor;
4853 pCur->pModule = pVtabCursor->pVtab->pModule;
4854 }else{
4855 db->mallocFailed = 1;
4856 pModule->xClose(pVtabCursor);
4857 }
4858 }
4859 break;
4860}
4861#endif /* SQLITE_OMIT_VIRTUALTABLE */
4862
4863#ifndef SQLITE_OMIT_VIRTUALTABLE
4864/* Opcode: VFilter P1 P2 P3
4865**
4866** P1 is a cursor opened using VOpen. P2 is an address to jump to if
4867** the filtered result set is empty.
4868**
4869** P3 is either NULL or a string that was generated by the xBestIndex
4870** method of the module. The interpretation of the P3 string is left
4871** to the module implementation.
4872**
4873** This opcode invokes the xFilter method on the virtual table specified
4874** by P1. The integer query plan parameter to xFilter is the top of the
4875** stack. Next down on the stack is the argc parameter. Beneath the
4876** next of stack are argc additional parameters which are passed to
4877** xFilter as argv. The topmost parameter (i.e. 3rd element popped from
4878** the stack) becomes argv[argc-1] when passed to xFilter.
4879**
4880** The integer query plan parameter, argc, and all argv stack values
4881** are popped from the stack before this instruction completes.
4882**
4883** A jump is made to P2 if the result set after filtering would be
4884** empty.
4885*/
4886case OP_VFilter: { /* no-push */
4887 int nArg;
4888
4889 const sqlite3_module *pModule;
4890
4891 Cursor *pCur = p->apCsr[pOp->p1];
4892 assert( pCur->pVtabCursor );
4893 pModule = pCur->pVtabCursor->pVtab->pModule;
4894
4895 /* Grab the index number and argc parameters off the top of the stack. */
4896 assert( (&pTos[-1])>=p->aStack );
4897 assert( (pTos[0].flags&MEM_Int)!=0 && pTos[-1].flags==MEM_Int );
4898 nArg = pTos[-1].u.i;
4899
4900 /* Invoke the xFilter method */
4901 {
4902 int res = 0;
4903 int i;
4904 Mem **apArg = p->apArg;
4905 for(i = 0; i<nArg; i++){
4906 apArg[i] = &pTos[i+1-2-nArg];
4907 storeTypeInfo(apArg[i], 0);
4908 }
4909
4910 if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
4911 p->inVtabMethod = 1;
4912 rc = pModule->xFilter(pCur->pVtabCursor, pTos->u.i, pOp->p3, nArg, apArg);
4913 p->inVtabMethod = 0;
4914 if( rc==SQLITE_OK ){
4915 res = pModule->xEof(pCur->pVtabCursor);
4916 }
4917 if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
4918
4919 if( res ){
4920 pc = pOp->p2 - 1;
4921 }
4922 }
4923
4924 /* Pop the index number, argc value and parameters off the stack */
4925 popStack(&pTos, 2+nArg);
4926 break;
4927}
4928#endif /* SQLITE_OMIT_VIRTUALTABLE */
4929
4930#ifndef SQLITE_OMIT_VIRTUALTABLE
4931/* Opcode: VRowid P1 * *
4932**
4933** Push an integer onto the stack which is the rowid of
4934** the virtual-table that the P1 cursor is pointing to.
4935*/
4936case OP_VRowid: {
4937 const sqlite3_module *pModule;
4938
4939 Cursor *pCur = p->apCsr[pOp->p1];
4940 assert( pCur->pVtabCursor );
4941 pModule = pCur->pVtabCursor->pVtab->pModule;
4942 if( pModule->xRowid==0 ){
4943 sqlite3SetString(&p->zErrMsg, "Unsupported module operation: xRowid", 0);
4944 rc = SQLITE_ERROR;
4945 } else {
4946 sqlite_int64 iRow;
4947
4948 if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
4949 rc = pModule->xRowid(pCur->pVtabCursor, &iRow);
4950 if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
4951
4952 pTos++;
4953 pTos->flags = MEM_Int;
4954 pTos->u.i = iRow;
4955 }
4956
4957 break;
4958}
4959#endif /* SQLITE_OMIT_VIRTUALTABLE */
4960
4961#ifndef SQLITE_OMIT_VIRTUALTABLE
4962/* Opcode: VColumn P1 P2 *
4963**
4964** Push onto the stack the value of the P2-th column of
4965** the row of the virtual-table that the P1 cursor is pointing to.
4966*/
4967case OP_VColumn: {
4968 const sqlite3_module *pModule;
4969
4970 Cursor *pCur = p->apCsr[pOp->p1];
4971 assert( pCur->pVtabCursor );
4972 pModule = pCur->pVtabCursor->pVtab->pModule;
4973 if( pModule->xColumn==0 ){
4974 sqlite3SetString(&p->zErrMsg, "Unsupported module operation: xColumn", 0);
4975 rc = SQLITE_ERROR;
4976 } else {
4977 sqlite3_context sContext;
4978 memset(&sContext, 0, sizeof(sContext));
4979 sContext.s.flags = MEM_Null;
4980 sContext.s.db = db;
4981 if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
4982 rc = pModule->xColumn(pCur->pVtabCursor, &sContext, pOp->p2);
4983
4984 /* Copy the result of the function to the top of the stack. We
4985 ** do this regardless of whether or not an error occured to ensure any
4986 ** dynamic allocation in sContext.s (a Mem struct) is released.
4987 */
4988 sqlite3VdbeChangeEncoding(&sContext.s, encoding);
4989 pTos++;
4990 pTos->flags = 0;
4991 sqlite3VdbeMemMove(pTos, &sContext.s);
4992
4993 if( sqlite3SafetyOn(db) ){
4994 goto abort_due_to_misuse;
4995 }
4996 if( sqlite3VdbeMemTooBig(pTos) ){
4997 goto too_big;
4998 }
4999 }
5000
5001 break;
5002}
5003#endif /* SQLITE_OMIT_VIRTUALTABLE */
5004
5005#ifndef SQLITE_OMIT_VIRTUALTABLE
5006/* Opcode: VNext P1 P2 *
5007**
5008** Advance virtual table P1 to the next row in its result set and
5009** jump to instruction P2. Or, if the virtual table has reached
5010** the end of its result set, then fall through to the next instruction.
5011*/
5012case OP_VNext: { /* no-push */
5013 const sqlite3_module *pModule;
5014 int res = 0;
5015
5016 Cursor *pCur = p->apCsr[pOp->p1];
5017 assert( pCur->pVtabCursor );
5018 pModule = pCur->pVtabCursor->pVtab->pModule;
5019 if( pModule->xNext==0 ){
5020 sqlite3SetString(&p->zErrMsg, "Unsupported module operation: xNext", 0);
5021 rc = SQLITE_ERROR;
5022 } else {
5023 /* Invoke the xNext() method of the module. There is no way for the
5024 ** underlying implementation to return an error if one occurs during
5025 ** xNext(). Instead, if an error occurs, true is returned (indicating that
5026 ** data is available) and the error code returned when xColumn or
5027 ** some other method is next invoked on the save virtual table cursor.
5028 */
5029 if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
5030 p->inVtabMethod = 1;
5031 rc = pModule->xNext(pCur->pVtabCursor);
5032 p->inVtabMethod = 0;
5033 if( rc==SQLITE_OK ){
5034 res = pModule->xEof(pCur->pVtabCursor);
5035 }
5036 if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
5037
5038 if( !res ){
5039 /* If there is data, jump to P2 */
5040 pc = pOp->p2 - 1;
5041 }
5042 }
5043
5044 break;
5045}
5046#endif /* SQLITE_OMIT_VIRTUALTABLE */
5047
5048#ifndef SQLITE_OMIT_VIRTUALTABLE
5049/* Opcode: VRename * * P3
5050**
5051** P3 is a pointer to a virtual table object, an sqlite3_vtab structure.
5052** This opcode invokes the corresponding xRename method. The value
5053** on the top of the stack is popped and passed as the zName argument
5054** to the xRename method.
5055*/
5056case OP_VRename: { /* no-push */
5057 sqlite3_vtab *pVtab = (sqlite3_vtab *)(pOp->p3);
5058 assert( pVtab->pModule->xRename );
5059
5060 Stringify(pTos, encoding);
5061
5062 if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
5063 sqlite3VtabLock(pVtab);
5064 rc = pVtab->pModule->xRename(pVtab, pTos->z);
5065 sqlite3VtabUnlock(db, pVtab);
5066 if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
5067
5068 popStack(&pTos, 1);
5069 break;
5070}
5071#endif
5072
5073#ifndef SQLITE_OMIT_VIRTUALTABLE
5074/* Opcode: VUpdate P1 P2 P3
5075**
5076** P3 is a pointer to a virtual table object, an sqlite3_vtab structure.
5077** This opcode invokes the corresponding xUpdate method. P2 values
5078** are taken from the stack to pass to the xUpdate invocation. The
5079** value on the top of the stack corresponds to the p2th element
5080** of the argv array passed to xUpdate.
5081**
5082** The xUpdate method will do a DELETE or an INSERT or both.
5083** The argv[0] element (which corresponds to the P2-th element down
5084** on the stack) is the rowid of a row to delete. If argv[0] is
5085** NULL then no deletion occurs. The argv[1] element is the rowid
5086** of the new row. This can be NULL to have the virtual table
5087** select the new rowid for itself. The higher elements in the
5088** stack are the values of columns in the new row.
5089**
5090** If P2==1 then no insert is performed. argv[0] is the rowid of
5091** a row to delete.
5092**
5093** P1 is a boolean flag. If it is set to true and the xUpdate call
5094** is successful, then the value returned by sqlite3_last_insert_rowid()
5095** is set to the value of the rowid for the row just inserted.
5096*/
5097case OP_VUpdate: { /* no-push */
5098 sqlite3_vtab *pVtab = (sqlite3_vtab *)(pOp->p3);
5099 sqlite3_module *pModule = (sqlite3_module *)pVtab->pModule;
5100 int nArg = pOp->p2;
5101 assert( pOp->p3type==P3_VTAB );
5102 if( pModule->xUpdate==0 ){
5103 sqlite3SetString(&p->zErrMsg, "read-only table", 0);
5104 rc = SQLITE_ERROR;
5105 }else{
5106 int i;
5107 sqlite_int64 rowid;
5108 Mem **apArg = p->apArg;
5109 Mem *pX = &pTos[1-nArg];
5110 for(i = 0; i<nArg; i++, pX++){
5111 storeTypeInfo(pX, 0);
5112 apArg[i] = pX;
5113 }
5114 if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
5115 sqlite3VtabLock(pVtab);
5116 rc = pModule->xUpdate(pVtab, nArg, apArg, &rowid);
5117 sqlite3VtabUnlock(db, pVtab);
5118 if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
5119 if( pOp->p1 && rc==SQLITE_OK ){
5120 assert( nArg>1 && apArg[0] && (apArg[0]->flags&MEM_Null) );
5121 db->lastRowid = rowid;
5122 }
5123 }
5124 popStack(&pTos, nArg);
5125 break;
5126}
5127#endif /* SQLITE_OMIT_VIRTUALTABLE */
5128
5129/* An other opcode is illegal...
5130*/
5131default: {
5132 assert( 0 );
5133 break;
5134}
5135
5136/*****************************************************************************
5137** The cases of the switch statement above this line should all be indented
5138** by 6 spaces. But the left-most 6 spaces have been removed to improve the
5139** readability. From this point on down, the normal indentation rules are
5140** restored.
5141*****************************************************************************/
5142 }
5143
5144 /* Make sure the stack limit was not exceeded */
5145 assert( pTos<=pStackLimit );
5146
5147#ifdef VDBE_PROFILE
5148 {
5149 long long elapse = hwtime() - start;
5150 pOp->cycles += elapse;
5151 pOp->cnt++;
5152#if 0
5153 fprintf(stdout, "%10lld ", elapse);
5154 sqlite3VdbePrintOp(stdout, origPc, &p->aOp[origPc]);
5155#endif
5156 }
5157#endif
5158
5159#ifdef SQLITE_TEST
5160 /* Keep track of the size of the largest BLOB or STR that has appeared
5161 ** on the top of the VDBE stack.
5162 */
5163 if( pTos>=p->aStack && (pTos->flags & (MEM_Blob|MEM_Str))!=0
5164 && pTos->n>sqlite3_max_blobsize ){
5165 sqlite3_max_blobsize = pTos->n;
5166 }
5167#endif
5168
5169 /* The following code adds nothing to the actual functionality
5170 ** of the program. It is only here for testing and debugging.
5171 ** On the other hand, it does burn CPU cycles every time through
5172 ** the evaluator loop. So we can leave it out when NDEBUG is defined.
5173 */
5174#ifndef NDEBUG
5175 /* Sanity checking on the top element of the stack. If the previous
5176 ** instruction was VNoChange, then the flags field of the top
5177 ** of the stack is set to 0. This is technically invalid for a memory
5178 ** cell, so avoid calling MemSanity() in this case.
5179 */
5180 if( pTos>=p->aStack && pTos->flags ){
5181 assert( pTos->db==db );
5182 sqlite3VdbeMemSanity(pTos);
5183 assert( !sqlite3VdbeMemTooBig(pTos) );
5184 }
5185 assert( pc>=-1 && pc<p->nOp );
5186
5187#ifdef SQLITE_DEBUG
5188 /* Code for tracing the vdbe stack. */
5189 if( p->trace && pTos>=p->aStack ){
5190 int i;
5191 fprintf(p->trace, "Stack:");
5192 for(i=0; i>-5 && &pTos[i]>=p->aStack; i--){
5193 if( pTos[i].flags & MEM_Null ){
5194 fprintf(p->trace, " NULL");
5195 }else if( (pTos[i].flags & (MEM_Int|MEM_Str))==(MEM_Int|MEM_Str) ){
5196 fprintf(p->trace, " si:%lld", pTos[i].u.i);
5197 }else if( pTos[i].flags & MEM_Int ){
5198 fprintf(p->trace, " i:%lld", pTos[i].u.i);
5199 }else if( pTos[i].flags & MEM_Real ){
5200 fprintf(p->trace, " r:%g", pTos[i].r);
5201 }else{
5202 char zBuf[200];
5203 sqlite3VdbeMemPrettyPrint(&pTos[i], zBuf);
5204 fprintf(p->trace, " ");
5205 fprintf(p->trace, "%s", zBuf);
5206 }
5207 }
5208 if( rc!=0 ) fprintf(p->trace," rc=%d",rc);
5209 fprintf(p->trace,"\n");
5210 }
5211#endif /* SQLITE_DEBUG */
5212#endif /* NDEBUG */
5213 } /* The end of the for(;;) loop the loops through opcodes */
5214
5215 /* If we reach this point, it means that execution is finished.
5216 */
5217vdbe_halt:
5218 if( rc ){
5219 p->rc = rc;
5220 rc = SQLITE_ERROR;
5221 }else{
5222 rc = SQLITE_DONE;
5223 }
5224 sqlite3VdbeHalt(p);
5225 p->pTos = pTos;
5226
5227 /* This is the only way out of this procedure. We have to
5228 ** release the mutexes on btrees that were acquired at the
5229 ** top. */
5230vdbe_return:
5231 sqlite3BtreeMutexArrayLeave(&p->aMutex);
5232 return rc;
5233
5234 /* Jump to here if a string or blob larger than SQLITE_MAX_LENGTH
5235 ** is encountered.
5236 */
5237too_big:
5238 sqlite3SetString(&p->zErrMsg, "string or blob too big", (char*)0);
5239 rc = SQLITE_TOOBIG;
5240 goto vdbe_halt;
5241
5242 /* Jump to here if a malloc() fails.
5243 */
5244no_mem:
5245 db->mallocFailed = 1;
5246 sqlite3SetString(&p->zErrMsg, "out of memory", (char*)0);
5247 rc = SQLITE_NOMEM;
5248 goto vdbe_halt;
5249
5250 /* Jump to here for an SQLITE_MISUSE error.
5251 */
5252abort_due_to_misuse:
5253 rc = SQLITE_MISUSE;
5254 /* Fall thru into abort_due_to_error */
5255
5256 /* Jump to here for any other kind of fatal error. The "rc" variable
5257 ** should hold the error number.
5258 */
5259abort_due_to_error:
5260 if( p->zErrMsg==0 ){
5261 if( db->mallocFailed ) rc = SQLITE_NOMEM;
5262 sqlite3SetString(&p->zErrMsg, sqlite3ErrStr(rc), (char*)0);
5263 }
5264 goto vdbe_halt;
5265
5266 /* Jump to here if the sqlite3_interrupt() API sets the interrupt
5267 ** flag.
5268 */
5269abort_due_to_interrupt:
5270 assert( db->u1.isInterrupted );
5271 if( db->magic!=SQLITE_MAGIC_BUSY ){
5272 rc = SQLITE_MISUSE;
5273 }else{
5274 rc = SQLITE_INTERRUPT;
5275 }
5276 p->rc = rc;
5277 sqlite3SetString(&p->zErrMsg, sqlite3ErrStr(rc), (char*)0);
5278 goto vdbe_halt;
5279}