xref: /sqlite-3.40.0/src/vdbeapi.c (revision 4f3557e4)
1 /*
2 ** 2004 May 26
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 **
13 ** This file contains code use to implement APIs that are part of the
14 ** VDBE.
15 */
16 #include "sqliteInt.h"
17 #include "vdbeInt.h"
18 
19 #ifndef SQLITE_OMIT_DEPRECATED
20 /*
21 ** Return TRUE (non-zero) of the statement supplied as an argument needs
22 ** to be recompiled.  A statement needs to be recompiled whenever the
23 ** execution environment changes in a way that would alter the program
24 ** that sqlite3_prepare() generates.  For example, if new functions or
25 ** collating sequences are registered or if an authorizer function is
26 ** added or changed.
27 */
28 int sqlite3_expired(sqlite3_stmt *pStmt){
29   Vdbe *p = (Vdbe*)pStmt;
30   return p==0 || p->expired;
31 }
32 #endif
33 
34 /*
35 ** Check on a Vdbe to make sure it has not been finalized.  Log
36 ** an error and return true if it has been finalized (or is otherwise
37 ** invalid).  Return false if it is ok.
38 */
39 static int vdbeSafety(Vdbe *p){
40   if( p->db==0 ){
41     sqlite3_log(SQLITE_MISUSE, "API called with finalized prepared statement");
42     return 1;
43   }else{
44     return 0;
45   }
46 }
47 static int vdbeSafetyNotNull(Vdbe *p){
48   if( p==0 ){
49     sqlite3_log(SQLITE_MISUSE, "API called with NULL prepared statement");
50     return 1;
51   }else{
52     return vdbeSafety(p);
53   }
54 }
55 
56 #ifndef SQLITE_OMIT_TRACE
57 /*
58 ** Invoke the profile callback.  This routine is only called if we already
59 ** know that the profile callback is defined and needs to be invoked.
60 */
61 static SQLITE_NOINLINE void invokeProfileCallback(sqlite3 *db, Vdbe *p){
62   sqlite3_int64 iNow;
63   sqlite3_int64 iElapse;
64   assert( p->startTime>0 );
65   assert( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0 );
66   assert( db->init.busy==0 );
67   assert( p->zSql!=0 );
68   sqlite3OsCurrentTimeInt64(db->pVfs, &iNow);
69   iElapse = (iNow - p->startTime)*1000000;
70 #ifndef SQLITE_OMIT_DEPRECATED
71   if( db->xProfile ){
72     db->xProfile(db->pProfileArg, p->zSql, iElapse);
73   }
74 #endif
75   if( db->mTrace & SQLITE_TRACE_PROFILE ){
76     db->trace.xV2(SQLITE_TRACE_PROFILE, db->pTraceArg, p, (void*)&iElapse);
77   }
78   p->startTime = 0;
79 }
80 /*
81 ** The checkProfileCallback(DB,P) macro checks to see if a profile callback
82 ** is needed, and it invokes the callback if it is needed.
83 */
84 # define checkProfileCallback(DB,P) \
85    if( ((P)->startTime)>0 ){ invokeProfileCallback(DB,P); }
86 #else
87 # define checkProfileCallback(DB,P)  /*no-op*/
88 #endif
89 
90 /*
91 ** The following routine destroys a virtual machine that is created by
92 ** the sqlite3_compile() routine. The integer returned is an SQLITE_
93 ** success/failure code that describes the result of executing the virtual
94 ** machine.
95 **
96 ** This routine sets the error code and string returned by
97 ** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
98 */
99 int sqlite3_finalize(sqlite3_stmt *pStmt){
100   int rc;
101   if( pStmt==0 ){
102     /* IMPLEMENTATION-OF: R-57228-12904 Invoking sqlite3_finalize() on a NULL
103     ** pointer is a harmless no-op. */
104     rc = SQLITE_OK;
105   }else{
106     Vdbe *v = (Vdbe*)pStmt;
107     sqlite3 *db = v->db;
108     if( vdbeSafety(v) ) return SQLITE_MISUSE_BKPT;
109     sqlite3_mutex_enter(db->mutex);
110     checkProfileCallback(db, v);
111     rc = sqlite3VdbeFinalize(v);
112     rc = sqlite3ApiExit(db, rc);
113     sqlite3LeaveMutexAndCloseZombie(db);
114   }
115   return rc;
116 }
117 
118 /*
119 ** Terminate the current execution of an SQL statement and reset it
120 ** back to its starting state so that it can be reused. A success code from
121 ** the prior execution is returned.
122 **
123 ** This routine sets the error code and string returned by
124 ** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
125 */
126 int sqlite3_reset(sqlite3_stmt *pStmt){
127   int rc;
128   if( pStmt==0 ){
129     rc = SQLITE_OK;
130   }else{
131     Vdbe *v = (Vdbe*)pStmt;
132     sqlite3 *db = v->db;
133     sqlite3_mutex_enter(db->mutex);
134     checkProfileCallback(db, v);
135     rc = sqlite3VdbeReset(v);
136     sqlite3VdbeRewind(v);
137     assert( (rc & (db->errMask))==rc );
138     rc = sqlite3ApiExit(db, rc);
139     sqlite3_mutex_leave(db->mutex);
140   }
141   return rc;
142 }
143 
144 /*
145 ** Set all the parameters in the compiled SQL statement to NULL.
146 */
147 int sqlite3_clear_bindings(sqlite3_stmt *pStmt){
148   int i;
149   int rc = SQLITE_OK;
150   Vdbe *p = (Vdbe*)pStmt;
151 #if SQLITE_THREADSAFE
152   sqlite3_mutex *mutex = ((Vdbe*)pStmt)->db->mutex;
153 #endif
154   sqlite3_mutex_enter(mutex);
155   for(i=0; i<p->nVar; i++){
156     sqlite3VdbeMemRelease(&p->aVar[i]);
157     p->aVar[i].flags = MEM_Null;
158   }
159   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || p->expmask==0 );
160   if( p->expmask ){
161     p->expired = 1;
162   }
163   sqlite3_mutex_leave(mutex);
164   return rc;
165 }
166 
167 
168 /**************************** sqlite3_value_  *******************************
169 ** The following routines extract information from a Mem or sqlite3_value
170 ** structure.
171 */
172 const void *sqlite3_value_blob(sqlite3_value *pVal){
173   Mem *p = (Mem*)pVal;
174   if( p->flags & (MEM_Blob|MEM_Str) ){
175     if( ExpandBlob(p)!=SQLITE_OK ){
176       assert( p->flags==MEM_Null && p->z==0 );
177       return 0;
178     }
179     p->flags |= MEM_Blob;
180     return p->n ? p->z : 0;
181   }else{
182     return sqlite3_value_text(pVal);
183   }
184 }
185 int sqlite3_value_bytes(sqlite3_value *pVal){
186   return sqlite3ValueBytes(pVal, SQLITE_UTF8);
187 }
188 int sqlite3_value_bytes16(sqlite3_value *pVal){
189   return sqlite3ValueBytes(pVal, SQLITE_UTF16NATIVE);
190 }
191 double sqlite3_value_double(sqlite3_value *pVal){
192   return sqlite3VdbeRealValue((Mem*)pVal);
193 }
194 int sqlite3_value_int(sqlite3_value *pVal){
195   return (int)sqlite3VdbeIntValue((Mem*)pVal);
196 }
197 sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
198   return sqlite3VdbeIntValue((Mem*)pVal);
199 }
200 unsigned int sqlite3_value_subtype(sqlite3_value *pVal){
201   Mem *pMem = (Mem*)pVal;
202   return ((pMem->flags & MEM_Subtype) ? pMem->eSubtype : 0);
203 }
204 void *sqlite3_value_pointer(sqlite3_value *pVal, const char *zPType){
205   Mem *p = (Mem*)pVal;
206   if( (p->flags&(MEM_TypeMask|MEM_Term|MEM_Subtype)) ==
207                  (MEM_Null|MEM_Term|MEM_Subtype)
208    && zPType!=0
209    && p->eSubtype=='p'
210    && strcmp(p->u.zPType, zPType)==0
211   ){
212     return (void*)p->z;
213   }else{
214     return 0;
215   }
216 }
217 const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
218   return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
219 }
220 #ifndef SQLITE_OMIT_UTF16
221 const void *sqlite3_value_text16(sqlite3_value* pVal){
222   return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
223 }
224 const void *sqlite3_value_text16be(sqlite3_value *pVal){
225   return sqlite3ValueText(pVal, SQLITE_UTF16BE);
226 }
227 const void *sqlite3_value_text16le(sqlite3_value *pVal){
228   return sqlite3ValueText(pVal, SQLITE_UTF16LE);
229 }
230 #endif /* SQLITE_OMIT_UTF16 */
231 /* EVIDENCE-OF: R-12793-43283 Every value in SQLite has one of five
232 ** fundamental datatypes: 64-bit signed integer 64-bit IEEE floating
233 ** point number string BLOB NULL
234 */
235 int sqlite3_value_type(sqlite3_value* pVal){
236   static const u8 aType[] = {
237      SQLITE_BLOB,     /* 0x00 (not possible) */
238      SQLITE_NULL,     /* 0x01 NULL */
239      SQLITE_TEXT,     /* 0x02 TEXT */
240      SQLITE_NULL,     /* 0x03 (not possible) */
241      SQLITE_INTEGER,  /* 0x04 INTEGER */
242      SQLITE_NULL,     /* 0x05 (not possible) */
243      SQLITE_INTEGER,  /* 0x06 INTEGER + TEXT */
244      SQLITE_NULL,     /* 0x07 (not possible) */
245      SQLITE_FLOAT,    /* 0x08 FLOAT */
246      SQLITE_NULL,     /* 0x09 (not possible) */
247      SQLITE_FLOAT,    /* 0x0a FLOAT + TEXT */
248      SQLITE_NULL,     /* 0x0b (not possible) */
249      SQLITE_INTEGER,  /* 0x0c (not possible) */
250      SQLITE_NULL,     /* 0x0d (not possible) */
251      SQLITE_INTEGER,  /* 0x0e (not possible) */
252      SQLITE_NULL,     /* 0x0f (not possible) */
253      SQLITE_BLOB,     /* 0x10 BLOB */
254      SQLITE_NULL,     /* 0x11 (not possible) */
255      SQLITE_TEXT,     /* 0x12 (not possible) */
256      SQLITE_NULL,     /* 0x13 (not possible) */
257      SQLITE_INTEGER,  /* 0x14 INTEGER + BLOB */
258      SQLITE_NULL,     /* 0x15 (not possible) */
259      SQLITE_INTEGER,  /* 0x16 (not possible) */
260      SQLITE_NULL,     /* 0x17 (not possible) */
261      SQLITE_FLOAT,    /* 0x18 FLOAT + BLOB */
262      SQLITE_NULL,     /* 0x19 (not possible) */
263      SQLITE_FLOAT,    /* 0x1a (not possible) */
264      SQLITE_NULL,     /* 0x1b (not possible) */
265      SQLITE_INTEGER,  /* 0x1c (not possible) */
266      SQLITE_NULL,     /* 0x1d (not possible) */
267      SQLITE_INTEGER,  /* 0x1e (not possible) */
268      SQLITE_NULL,     /* 0x1f (not possible) */
269      SQLITE_FLOAT,    /* 0x20 INTREAL */
270      SQLITE_NULL,     /* 0x21 (not possible) */
271      SQLITE_TEXT,     /* 0x22 INTREAL + TEXT */
272      SQLITE_NULL,     /* 0x23 (not possible) */
273      SQLITE_FLOAT,    /* 0x24 (not possible) */
274      SQLITE_NULL,     /* 0x25 (not possible) */
275      SQLITE_FLOAT,    /* 0x26 (not possible) */
276      SQLITE_NULL,     /* 0x27 (not possible) */
277      SQLITE_FLOAT,    /* 0x28 (not possible) */
278      SQLITE_NULL,     /* 0x29 (not possible) */
279      SQLITE_FLOAT,    /* 0x2a (not possible) */
280      SQLITE_NULL,     /* 0x2b (not possible) */
281      SQLITE_FLOAT,    /* 0x2c (not possible) */
282      SQLITE_NULL,     /* 0x2d (not possible) */
283      SQLITE_FLOAT,    /* 0x2e (not possible) */
284      SQLITE_NULL,     /* 0x2f (not possible) */
285      SQLITE_BLOB,     /* 0x30 (not possible) */
286      SQLITE_NULL,     /* 0x31 (not possible) */
287      SQLITE_TEXT,     /* 0x32 (not possible) */
288      SQLITE_NULL,     /* 0x33 (not possible) */
289      SQLITE_FLOAT,    /* 0x34 (not possible) */
290      SQLITE_NULL,     /* 0x35 (not possible) */
291      SQLITE_FLOAT,    /* 0x36 (not possible) */
292      SQLITE_NULL,     /* 0x37 (not possible) */
293      SQLITE_FLOAT,    /* 0x38 (not possible) */
294      SQLITE_NULL,     /* 0x39 (not possible) */
295      SQLITE_FLOAT,    /* 0x3a (not possible) */
296      SQLITE_NULL,     /* 0x3b (not possible) */
297      SQLITE_FLOAT,    /* 0x3c (not possible) */
298      SQLITE_NULL,     /* 0x3d (not possible) */
299      SQLITE_FLOAT,    /* 0x3e (not possible) */
300      SQLITE_NULL,     /* 0x3f (not possible) */
301   };
302 #ifdef SQLITE_DEBUG
303   {
304     int eType = SQLITE_BLOB;
305     if( pVal->flags & MEM_Null ){
306       eType = SQLITE_NULL;
307     }else if( pVal->flags & (MEM_Real|MEM_IntReal) ){
308       eType = SQLITE_FLOAT;
309     }else if( pVal->flags & MEM_Int ){
310       eType = SQLITE_INTEGER;
311     }else if( pVal->flags & MEM_Str ){
312       eType = SQLITE_TEXT;
313     }
314     assert( eType == aType[pVal->flags&MEM_AffMask] );
315   }
316 #endif
317   return aType[pVal->flags&MEM_AffMask];
318 }
319 
320 /* Return true if a parameter to xUpdate represents an unchanged column */
321 int sqlite3_value_nochange(sqlite3_value *pVal){
322   return (pVal->flags&(MEM_Null|MEM_Zero))==(MEM_Null|MEM_Zero);
323 }
324 
325 /* Return true if a parameter value originated from an sqlite3_bind() */
326 int sqlite3_value_frombind(sqlite3_value *pVal){
327   return (pVal->flags&MEM_FromBind)!=0;
328 }
329 
330 /* Make a copy of an sqlite3_value object
331 */
332 sqlite3_value *sqlite3_value_dup(const sqlite3_value *pOrig){
333   sqlite3_value *pNew;
334   if( pOrig==0 ) return 0;
335   pNew = sqlite3_malloc( sizeof(*pNew) );
336   if( pNew==0 ) return 0;
337   memset(pNew, 0, sizeof(*pNew));
338   memcpy(pNew, pOrig, MEMCELLSIZE);
339   pNew->flags &= ~MEM_Dyn;
340   pNew->db = 0;
341   if( pNew->flags&(MEM_Str|MEM_Blob) ){
342     pNew->flags &= ~(MEM_Static|MEM_Dyn);
343     pNew->flags |= MEM_Ephem;
344     if( sqlite3VdbeMemMakeWriteable(pNew)!=SQLITE_OK ){
345       sqlite3ValueFree(pNew);
346       pNew = 0;
347     }
348   }
349   return pNew;
350 }
351 
352 /* Destroy an sqlite3_value object previously obtained from
353 ** sqlite3_value_dup().
354 */
355 void sqlite3_value_free(sqlite3_value *pOld){
356   sqlite3ValueFree(pOld);
357 }
358 
359 
360 /**************************** sqlite3_result_  *******************************
361 ** The following routines are used by user-defined functions to specify
362 ** the function result.
363 **
364 ** The setStrOrError() function calls sqlite3VdbeMemSetStr() to store the
365 ** result as a string or blob.  Appropriate errors are set if the string/blob
366 ** is too big or if an OOM occurs.
367 **
368 ** The invokeValueDestructor(P,X) routine invokes destructor function X()
369 ** on value P is not going to be used and need to be destroyed.
370 */
371 static void setResultStrOrError(
372   sqlite3_context *pCtx,  /* Function context */
373   const char *z,          /* String pointer */
374   int n,                  /* Bytes in string, or negative */
375   u8 enc,                 /* Encoding of z.  0 for BLOBs */
376   void (*xDel)(void*)     /* Destructor function */
377 ){
378   int rc = sqlite3VdbeMemSetStr(pCtx->pOut, z, n, enc, xDel);
379   if( rc ){
380     if( rc==SQLITE_TOOBIG ){
381       sqlite3_result_error_toobig(pCtx);
382     }else{
383       /* The only errors possible from sqlite3VdbeMemSetStr are
384       ** SQLITE_TOOBIG and SQLITE_NOMEM */
385       assert( rc==SQLITE_NOMEM );
386       sqlite3_result_error_nomem(pCtx);
387     }
388   }
389 }
390 static int invokeValueDestructor(
391   const void *p,             /* Value to destroy */
392   void (*xDel)(void*),       /* The destructor */
393   sqlite3_context *pCtx      /* Set a SQLITE_TOOBIG error if no NULL */
394 ){
395   assert( xDel!=SQLITE_DYNAMIC );
396   if( xDel==0 ){
397     /* noop */
398   }else if( xDel==SQLITE_TRANSIENT ){
399     /* noop */
400   }else{
401     xDel((void*)p);
402   }
403   sqlite3_result_error_toobig(pCtx);
404   return SQLITE_TOOBIG;
405 }
406 void sqlite3_result_blob(
407   sqlite3_context *pCtx,
408   const void *z,
409   int n,
410   void (*xDel)(void *)
411 ){
412   assert( n>=0 );
413   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
414   setResultStrOrError(pCtx, z, n, 0, xDel);
415 }
416 void sqlite3_result_blob64(
417   sqlite3_context *pCtx,
418   const void *z,
419   sqlite3_uint64 n,
420   void (*xDel)(void *)
421 ){
422   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
423   assert( xDel!=SQLITE_DYNAMIC );
424   if( n>0x7fffffff ){
425     (void)invokeValueDestructor(z, xDel, pCtx);
426   }else{
427     setResultStrOrError(pCtx, z, (int)n, 0, xDel);
428   }
429 }
430 void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
431   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
432   sqlite3VdbeMemSetDouble(pCtx->pOut, rVal);
433 }
434 void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
435   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
436   pCtx->isError = SQLITE_ERROR;
437   sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
438 }
439 #ifndef SQLITE_OMIT_UTF16
440 void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
441   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
442   pCtx->isError = SQLITE_ERROR;
443   sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
444 }
445 #endif
446 void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
447   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
448   sqlite3VdbeMemSetInt64(pCtx->pOut, (i64)iVal);
449 }
450 void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
451   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
452   sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);
453 }
454 void sqlite3_result_null(sqlite3_context *pCtx){
455   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
456   sqlite3VdbeMemSetNull(pCtx->pOut);
457 }
458 void sqlite3_result_pointer(
459   sqlite3_context *pCtx,
460   void *pPtr,
461   const char *zPType,
462   void (*xDestructor)(void*)
463 ){
464   Mem *pOut = pCtx->pOut;
465   assert( sqlite3_mutex_held(pOut->db->mutex) );
466   sqlite3VdbeMemRelease(pOut);
467   pOut->flags = MEM_Null;
468   sqlite3VdbeMemSetPointer(pOut, pPtr, zPType, xDestructor);
469 }
470 void sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){
471   Mem *pOut = pCtx->pOut;
472   assert( sqlite3_mutex_held(pOut->db->mutex) );
473   pOut->eSubtype = eSubtype & 0xff;
474   pOut->flags |= MEM_Subtype;
475 }
476 void sqlite3_result_text(
477   sqlite3_context *pCtx,
478   const char *z,
479   int n,
480   void (*xDel)(void *)
481 ){
482   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
483   setResultStrOrError(pCtx, z, n, SQLITE_UTF8, xDel);
484 }
485 void sqlite3_result_text64(
486   sqlite3_context *pCtx,
487   const char *z,
488   sqlite3_uint64 n,
489   void (*xDel)(void *),
490   unsigned char enc
491 ){
492   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
493   assert( xDel!=SQLITE_DYNAMIC );
494   if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;
495   if( n>0x7fffffff ){
496     (void)invokeValueDestructor(z, xDel, pCtx);
497   }else{
498     setResultStrOrError(pCtx, z, (int)n, enc, xDel);
499   }
500 }
501 #ifndef SQLITE_OMIT_UTF16
502 void sqlite3_result_text16(
503   sqlite3_context *pCtx,
504   const void *z,
505   int n,
506   void (*xDel)(void *)
507 ){
508   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
509   setResultStrOrError(pCtx, z, n, SQLITE_UTF16NATIVE, xDel);
510 }
511 void sqlite3_result_text16be(
512   sqlite3_context *pCtx,
513   const void *z,
514   int n,
515   void (*xDel)(void *)
516 ){
517   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
518   setResultStrOrError(pCtx, z, n, SQLITE_UTF16BE, xDel);
519 }
520 void sqlite3_result_text16le(
521   sqlite3_context *pCtx,
522   const void *z,
523   int n,
524   void (*xDel)(void *)
525 ){
526   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
527   setResultStrOrError(pCtx, z, n, SQLITE_UTF16LE, xDel);
528 }
529 #endif /* SQLITE_OMIT_UTF16 */
530 void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
531   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
532   sqlite3VdbeMemCopy(pCtx->pOut, pValue);
533 }
534 void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
535   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
536   sqlite3VdbeMemSetZeroBlob(pCtx->pOut, n);
537 }
538 int sqlite3_result_zeroblob64(sqlite3_context *pCtx, u64 n){
539   Mem *pOut = pCtx->pOut;
540   assert( sqlite3_mutex_held(pOut->db->mutex) );
541   if( n>(u64)pOut->db->aLimit[SQLITE_LIMIT_LENGTH] ){
542     return SQLITE_TOOBIG;
543   }
544 #ifndef SQLITE_OMIT_INCRBLOB
545   sqlite3VdbeMemSetZeroBlob(pCtx->pOut, (int)n);
546   return SQLITE_OK;
547 #else
548   return sqlite3VdbeMemSetZeroBlob(pCtx->pOut, (int)n);
549 #endif
550 }
551 void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
552   pCtx->isError = errCode ? errCode : -1;
553 #ifdef SQLITE_DEBUG
554   if( pCtx->pVdbe ) pCtx->pVdbe->rcApp = errCode;
555 #endif
556   if( pCtx->pOut->flags & MEM_Null ){
557     sqlite3VdbeMemSetStr(pCtx->pOut, sqlite3ErrStr(errCode), -1,
558                          SQLITE_UTF8, SQLITE_STATIC);
559   }
560 }
561 
562 /* Force an SQLITE_TOOBIG error. */
563 void sqlite3_result_error_toobig(sqlite3_context *pCtx){
564   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
565   pCtx->isError = SQLITE_TOOBIG;
566   sqlite3VdbeMemSetStr(pCtx->pOut, "string or blob too big", -1,
567                        SQLITE_UTF8, SQLITE_STATIC);
568 }
569 
570 /* An SQLITE_NOMEM error. */
571 void sqlite3_result_error_nomem(sqlite3_context *pCtx){
572   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
573   sqlite3VdbeMemSetNull(pCtx->pOut);
574   pCtx->isError = SQLITE_NOMEM_BKPT;
575   sqlite3OomFault(pCtx->pOut->db);
576 }
577 
578 #ifndef SQLITE_UNTESTABLE
579 /* Force the INT64 value currently stored as the result to be
580 ** a MEM_IntReal value.  See the SQLITE_TESTCTRL_RESULT_INTREAL
581 ** test-control.
582 */
583 void sqlite3ResultIntReal(sqlite3_context *pCtx){
584   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
585   if( pCtx->pOut->flags & MEM_Int ){
586     pCtx->pOut->flags &= ~MEM_Int;
587     pCtx->pOut->flags |= MEM_IntReal;
588   }
589 }
590 #endif
591 
592 
593 /*
594 ** This function is called after a transaction has been committed. It
595 ** invokes callbacks registered with sqlite3_wal_hook() as required.
596 */
597 static int doWalCallbacks(sqlite3 *db){
598   int rc = SQLITE_OK;
599 #ifndef SQLITE_OMIT_WAL
600   int i;
601   for(i=0; i<db->nDb; i++){
602     Btree *pBt = db->aDb[i].pBt;
603     if( pBt ){
604       int nEntry;
605       sqlite3BtreeEnter(pBt);
606       nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));
607       sqlite3BtreeLeave(pBt);
608       if( nEntry>0 && db->xWalCallback && rc==SQLITE_OK ){
609         rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zDbSName, nEntry);
610       }
611     }
612   }
613 #endif
614   return rc;
615 }
616 
617 
618 /*
619 ** Execute the statement pStmt, either until a row of data is ready, the
620 ** statement is completely executed or an error occurs.
621 **
622 ** This routine implements the bulk of the logic behind the sqlite_step()
623 ** API.  The only thing omitted is the automatic recompile if a
624 ** schema change has occurred.  That detail is handled by the
625 ** outer sqlite3_step() wrapper procedure.
626 */
627 static int sqlite3Step(Vdbe *p){
628   sqlite3 *db;
629   int rc;
630 
631   assert(p);
632   if( p->iVdbeMagic!=VDBE_MAGIC_RUN ){
633     /* We used to require that sqlite3_reset() be called before retrying
634     ** sqlite3_step() after any error or after SQLITE_DONE.  But beginning
635     ** with version 3.7.0, we changed this so that sqlite3_reset() would
636     ** be called automatically instead of throwing the SQLITE_MISUSE error.
637     ** This "automatic-reset" change is not technically an incompatibility,
638     ** since any application that receives an SQLITE_MISUSE is broken by
639     ** definition.
640     **
641     ** Nevertheless, some published applications that were originally written
642     ** for version 3.6.23 or earlier do in fact depend on SQLITE_MISUSE
643     ** returns, and those were broken by the automatic-reset change.  As a
644     ** a work-around, the SQLITE_OMIT_AUTORESET compile-time restores the
645     ** legacy behavior of returning SQLITE_MISUSE for cases where the
646     ** previous sqlite3_step() returned something other than a SQLITE_LOCKED
647     ** or SQLITE_BUSY error.
648     */
649 #ifdef SQLITE_OMIT_AUTORESET
650     if( (rc = p->rc&0xff)==SQLITE_BUSY || rc==SQLITE_LOCKED ){
651       sqlite3_reset((sqlite3_stmt*)p);
652     }else{
653       return SQLITE_MISUSE_BKPT;
654     }
655 #else
656     sqlite3_reset((sqlite3_stmt*)p);
657 #endif
658   }
659 
660   /* Check that malloc() has not failed. If it has, return early. */
661   db = p->db;
662   if( db->mallocFailed ){
663     p->rc = SQLITE_NOMEM;
664     return SQLITE_NOMEM_BKPT;
665   }
666 
667   if( p->pc<0 && p->expired ){
668     p->rc = SQLITE_SCHEMA;
669     rc = SQLITE_ERROR;
670     if( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ){
671       /* If this statement was prepared using saved SQL and an
672       ** error has occurred, then return the error code in p->rc to the
673       ** caller. Set the error code in the database handle to the same value.
674       */
675       rc = sqlite3VdbeTransferError(p);
676     }
677     goto end_of_step;
678   }
679   if( p->pc<0 ){
680     /* If there are no other statements currently running, then
681     ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
682     ** from interrupting a statement that has not yet started.
683     */
684     if( db->nVdbeActive==0 ){
685       AtomicStore(&db->u1.isInterrupted, 0);
686     }
687 
688     assert( db->nVdbeWrite>0 || db->autoCommit==0
689         || (db->nDeferredCons==0 && db->nDeferredImmCons==0)
690     );
691 
692 #ifndef SQLITE_OMIT_TRACE
693     if( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0
694         && !db->init.busy && p->zSql ){
695       sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);
696     }else{
697       assert( p->startTime==0 );
698     }
699 #endif
700 
701     db->nVdbeActive++;
702     if( p->readOnly==0 ) db->nVdbeWrite++;
703     if( p->bIsReader ) db->nVdbeRead++;
704     p->pc = 0;
705   }
706 #ifdef SQLITE_DEBUG
707   p->rcApp = SQLITE_OK;
708 #endif
709 #ifndef SQLITE_OMIT_EXPLAIN
710   if( p->explain ){
711     rc = sqlite3VdbeList(p);
712   }else
713 #endif /* SQLITE_OMIT_EXPLAIN */
714   {
715     db->nVdbeExec++;
716     rc = sqlite3VdbeExec(p);
717     db->nVdbeExec--;
718   }
719 
720   if( rc!=SQLITE_ROW ){
721 #ifndef SQLITE_OMIT_TRACE
722     /* If the statement completed successfully, invoke the profile callback */
723     checkProfileCallback(db, p);
724 #endif
725 
726     if( rc==SQLITE_DONE && db->autoCommit ){
727       assert( p->rc==SQLITE_OK );
728       p->rc = doWalCallbacks(db);
729       if( p->rc!=SQLITE_OK ){
730         rc = SQLITE_ERROR;
731       }
732     }else if( rc!=SQLITE_DONE && (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ){
733       /* If this statement was prepared using saved SQL and an
734       ** error has occurred, then return the error code in p->rc to the
735       ** caller. Set the error code in the database handle to the same value.
736       */
737       rc = sqlite3VdbeTransferError(p);
738     }
739   }
740 
741   db->errCode = rc;
742   if( SQLITE_NOMEM==sqlite3ApiExit(p->db, p->rc) ){
743     p->rc = SQLITE_NOMEM_BKPT;
744     if( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ) rc = p->rc;
745   }
746 end_of_step:
747   /* There are only a limited number of result codes allowed from the
748   ** statements prepared using the legacy sqlite3_prepare() interface */
749   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0
750        || rc==SQLITE_ROW  || rc==SQLITE_DONE   || rc==SQLITE_ERROR
751        || (rc&0xff)==SQLITE_BUSY || rc==SQLITE_MISUSE
752   );
753   return (rc&db->errMask);
754 }
755 
756 /*
757 ** This is the top-level implementation of sqlite3_step().  Call
758 ** sqlite3Step() to do most of the work.  If a schema error occurs,
759 ** call sqlite3Reprepare() and try again.
760 */
761 int sqlite3_step(sqlite3_stmt *pStmt){
762   int rc = SQLITE_OK;      /* Result from sqlite3Step() */
763   Vdbe *v = (Vdbe*)pStmt;  /* the prepared statement */
764   int cnt = 0;             /* Counter to prevent infinite loop of reprepares */
765   sqlite3 *db;             /* The database connection */
766 
767   if( vdbeSafetyNotNull(v) ){
768     return SQLITE_MISUSE_BKPT;
769   }
770   db = v->db;
771   sqlite3_mutex_enter(db->mutex);
772   v->doingRerun = 0;
773   while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
774          && cnt++ < SQLITE_MAX_SCHEMA_RETRY ){
775     int savedPc = v->pc;
776     rc = sqlite3Reprepare(v);
777     if( rc!=SQLITE_OK ){
778       /* This case occurs after failing to recompile an sql statement.
779       ** The error message from the SQL compiler has already been loaded
780       ** into the database handle. This block copies the error message
781       ** from the database handle into the statement and sets the statement
782       ** program counter to 0 to ensure that when the statement is
783       ** finalized or reset the parser error message is available via
784       ** sqlite3_errmsg() and sqlite3_errcode().
785       */
786       const char *zErr = (const char *)sqlite3_value_text(db->pErr);
787       sqlite3DbFree(db, v->zErrMsg);
788       if( !db->mallocFailed ){
789         v->zErrMsg = sqlite3DbStrDup(db, zErr);
790         v->rc = rc = sqlite3ApiExit(db, rc);
791       } else {
792         v->zErrMsg = 0;
793         v->rc = rc = SQLITE_NOMEM_BKPT;
794       }
795       break;
796     }
797     sqlite3_reset(pStmt);
798     if( savedPc>=0 ) v->doingRerun = 1;
799     assert( v->expired==0 );
800   }
801   sqlite3_mutex_leave(db->mutex);
802   return rc;
803 }
804 
805 
806 /*
807 ** Extract the user data from a sqlite3_context structure and return a
808 ** pointer to it.
809 */
810 void *sqlite3_user_data(sqlite3_context *p){
811   assert( p && p->pFunc );
812   return p->pFunc->pUserData;
813 }
814 
815 /*
816 ** Extract the user data from a sqlite3_context structure and return a
817 ** pointer to it.
818 **
819 ** IMPLEMENTATION-OF: R-46798-50301 The sqlite3_context_db_handle() interface
820 ** returns a copy of the pointer to the database connection (the 1st
821 ** parameter) of the sqlite3_create_function() and
822 ** sqlite3_create_function16() routines that originally registered the
823 ** application defined function.
824 */
825 sqlite3 *sqlite3_context_db_handle(sqlite3_context *p){
826   assert( p && p->pOut );
827   return p->pOut->db;
828 }
829 
830 /*
831 ** If this routine is invoked from within an xColumn method of a virtual
832 ** table, then it returns true if and only if the the call is during an
833 ** UPDATE operation and the value of the column will not be modified
834 ** by the UPDATE.
835 **
836 ** If this routine is called from any context other than within the
837 ** xColumn method of a virtual table, then the return value is meaningless
838 ** and arbitrary.
839 **
840 ** Virtual table implements might use this routine to optimize their
841 ** performance by substituting a NULL result, or some other light-weight
842 ** value, as a signal to the xUpdate routine that the column is unchanged.
843 */
844 int sqlite3_vtab_nochange(sqlite3_context *p){
845   assert( p );
846   return sqlite3_value_nochange(p->pOut);
847 }
848 
849 /*
850 ** Return the current time for a statement.  If the current time
851 ** is requested more than once within the same run of a single prepared
852 ** statement, the exact same time is returned for each invocation regardless
853 ** of the amount of time that elapses between invocations.  In other words,
854 ** the time returned is always the time of the first call.
855 */
856 sqlite3_int64 sqlite3StmtCurrentTime(sqlite3_context *p){
857   int rc;
858 #ifndef SQLITE_ENABLE_STAT4
859   sqlite3_int64 *piTime = &p->pVdbe->iCurrentTime;
860   assert( p->pVdbe!=0 );
861 #else
862   sqlite3_int64 iTime = 0;
863   sqlite3_int64 *piTime = p->pVdbe!=0 ? &p->pVdbe->iCurrentTime : &iTime;
864 #endif
865   if( *piTime==0 ){
866     rc = sqlite3OsCurrentTimeInt64(p->pOut->db->pVfs, piTime);
867     if( rc ) *piTime = 0;
868   }
869   return *piTime;
870 }
871 
872 /*
873 ** Create a new aggregate context for p and return a pointer to
874 ** its pMem->z element.
875 */
876 static SQLITE_NOINLINE void *createAggContext(sqlite3_context *p, int nByte){
877   Mem *pMem = p->pMem;
878   assert( (pMem->flags & MEM_Agg)==0 );
879   if( nByte<=0 ){
880     sqlite3VdbeMemSetNull(pMem);
881     pMem->z = 0;
882   }else{
883     sqlite3VdbeMemClearAndResize(pMem, nByte);
884     pMem->flags = MEM_Agg;
885     pMem->u.pDef = p->pFunc;
886     if( pMem->z ){
887       memset(pMem->z, 0, nByte);
888     }
889   }
890   return (void*)pMem->z;
891 }
892 
893 /*
894 ** Allocate or return the aggregate context for a user function.  A new
895 ** context is allocated on the first call.  Subsequent calls return the
896 ** same context that was returned on prior calls.
897 */
898 void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
899   assert( p && p->pFunc && p->pFunc->xFinalize );
900   assert( sqlite3_mutex_held(p->pOut->db->mutex) );
901   testcase( nByte<0 );
902   if( (p->pMem->flags & MEM_Agg)==0 ){
903     return createAggContext(p, nByte);
904   }else{
905     return (void*)p->pMem->z;
906   }
907 }
908 
909 /*
910 ** Return the auxiliary data pointer, if any, for the iArg'th argument to
911 ** the user-function defined by pCtx.
912 **
913 ** The left-most argument is 0.
914 **
915 ** Undocumented behavior:  If iArg is negative then access a cache of
916 ** auxiliary data pointers that is available to all functions within a
917 ** single prepared statement.  The iArg values must match.
918 */
919 void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
920   AuxData *pAuxData;
921 
922   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
923 #if SQLITE_ENABLE_STAT4
924   if( pCtx->pVdbe==0 ) return 0;
925 #else
926   assert( pCtx->pVdbe!=0 );
927 #endif
928   for(pAuxData=pCtx->pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
929     if(  pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
930       return pAuxData->pAux;
931     }
932   }
933   return 0;
934 }
935 
936 /*
937 ** Set the auxiliary data pointer and delete function, for the iArg'th
938 ** argument to the user-function defined by pCtx. Any previous value is
939 ** deleted by calling the delete function specified when it was set.
940 **
941 ** The left-most argument is 0.
942 **
943 ** Undocumented behavior:  If iArg is negative then make the data available
944 ** to all functions within the current prepared statement using iArg as an
945 ** access code.
946 */
947 void sqlite3_set_auxdata(
948   sqlite3_context *pCtx,
949   int iArg,
950   void *pAux,
951   void (*xDelete)(void*)
952 ){
953   AuxData *pAuxData;
954   Vdbe *pVdbe = pCtx->pVdbe;
955 
956   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
957 #ifdef SQLITE_ENABLE_STAT4
958   if( pVdbe==0 ) goto failed;
959 #else
960   assert( pVdbe!=0 );
961 #endif
962 
963   for(pAuxData=pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
964     if( pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
965       break;
966     }
967   }
968   if( pAuxData==0 ){
969     pAuxData = sqlite3DbMallocZero(pVdbe->db, sizeof(AuxData));
970     if( !pAuxData ) goto failed;
971     pAuxData->iAuxOp = pCtx->iOp;
972     pAuxData->iAuxArg = iArg;
973     pAuxData->pNextAux = pVdbe->pAuxData;
974     pVdbe->pAuxData = pAuxData;
975     if( pCtx->isError==0 ) pCtx->isError = -1;
976   }else if( pAuxData->xDeleteAux ){
977     pAuxData->xDeleteAux(pAuxData->pAux);
978   }
979 
980   pAuxData->pAux = pAux;
981   pAuxData->xDeleteAux = xDelete;
982   return;
983 
984 failed:
985   if( xDelete ){
986     xDelete(pAux);
987   }
988 }
989 
990 #ifndef SQLITE_OMIT_DEPRECATED
991 /*
992 ** Return the number of times the Step function of an aggregate has been
993 ** called.
994 **
995 ** This function is deprecated.  Do not use it for new code.  It is
996 ** provide only to avoid breaking legacy code.  New aggregate function
997 ** implementations should keep their own counts within their aggregate
998 ** context.
999 */
1000 int sqlite3_aggregate_count(sqlite3_context *p){
1001   assert( p && p->pMem && p->pFunc && p->pFunc->xFinalize );
1002   return p->pMem->n;
1003 }
1004 #endif
1005 
1006 /*
1007 ** Return the number of columns in the result set for the statement pStmt.
1008 */
1009 int sqlite3_column_count(sqlite3_stmt *pStmt){
1010   Vdbe *pVm = (Vdbe *)pStmt;
1011   return pVm ? pVm->nResColumn : 0;
1012 }
1013 
1014 /*
1015 ** Return the number of values available from the current row of the
1016 ** currently executing statement pStmt.
1017 */
1018 int sqlite3_data_count(sqlite3_stmt *pStmt){
1019   Vdbe *pVm = (Vdbe *)pStmt;
1020   if( pVm==0 || pVm->pResultSet==0 ) return 0;
1021   return pVm->nResColumn;
1022 }
1023 
1024 /*
1025 ** Return a pointer to static memory containing an SQL NULL value.
1026 */
1027 static const Mem *columnNullValue(void){
1028   /* Even though the Mem structure contains an element
1029   ** of type i64, on certain architectures (x86) with certain compiler
1030   ** switches (-Os), gcc may align this Mem object on a 4-byte boundary
1031   ** instead of an 8-byte one. This all works fine, except that when
1032   ** running with SQLITE_DEBUG defined the SQLite code sometimes assert()s
1033   ** that a Mem structure is located on an 8-byte boundary. To prevent
1034   ** these assert()s from failing, when building with SQLITE_DEBUG defined
1035   ** using gcc, we force nullMem to be 8-byte aligned using the magical
1036   ** __attribute__((aligned(8))) macro.  */
1037   static const Mem nullMem
1038 #if defined(SQLITE_DEBUG) && defined(__GNUC__)
1039     __attribute__((aligned(8)))
1040 #endif
1041     = {
1042         /* .u          = */ {0},
1043         /* .flags      = */ (u16)MEM_Null,
1044         /* .enc        = */ (u8)0,
1045         /* .eSubtype   = */ (u8)0,
1046         /* .n          = */ (int)0,
1047         /* .z          = */ (char*)0,
1048         /* .zMalloc    = */ (char*)0,
1049         /* .szMalloc   = */ (int)0,
1050         /* .uTemp      = */ (u32)0,
1051         /* .db         = */ (sqlite3*)0,
1052         /* .xDel       = */ (void(*)(void*))0,
1053 #ifdef SQLITE_DEBUG
1054         /* .pScopyFrom = */ (Mem*)0,
1055         /* .mScopyFlags= */ 0,
1056 #endif
1057       };
1058   return &nullMem;
1059 }
1060 
1061 /*
1062 ** Check to see if column iCol of the given statement is valid.  If
1063 ** it is, return a pointer to the Mem for the value of that column.
1064 ** If iCol is not valid, return a pointer to a Mem which has a value
1065 ** of NULL.
1066 */
1067 static Mem *columnMem(sqlite3_stmt *pStmt, int i){
1068   Vdbe *pVm;
1069   Mem *pOut;
1070 
1071   pVm = (Vdbe *)pStmt;
1072   if( pVm==0 ) return (Mem*)columnNullValue();
1073   assert( pVm->db );
1074   sqlite3_mutex_enter(pVm->db->mutex);
1075   if( pVm->pResultSet!=0 && i<pVm->nResColumn && i>=0 ){
1076     pOut = &pVm->pResultSet[i];
1077   }else{
1078     sqlite3Error(pVm->db, SQLITE_RANGE);
1079     pOut = (Mem*)columnNullValue();
1080   }
1081   return pOut;
1082 }
1083 
1084 /*
1085 ** This function is called after invoking an sqlite3_value_XXX function on a
1086 ** column value (i.e. a value returned by evaluating an SQL expression in the
1087 ** select list of a SELECT statement) that may cause a malloc() failure. If
1088 ** malloc() has failed, the threads mallocFailed flag is cleared and the result
1089 ** code of statement pStmt set to SQLITE_NOMEM.
1090 **
1091 ** Specifically, this is called from within:
1092 **
1093 **     sqlite3_column_int()
1094 **     sqlite3_column_int64()
1095 **     sqlite3_column_text()
1096 **     sqlite3_column_text16()
1097 **     sqlite3_column_real()
1098 **     sqlite3_column_bytes()
1099 **     sqlite3_column_bytes16()
1100 **     sqiite3_column_blob()
1101 */
1102 static void columnMallocFailure(sqlite3_stmt *pStmt)
1103 {
1104   /* If malloc() failed during an encoding conversion within an
1105   ** sqlite3_column_XXX API, then set the return code of the statement to
1106   ** SQLITE_NOMEM. The next call to _step() (if any) will return SQLITE_ERROR
1107   ** and _finalize() will return NOMEM.
1108   */
1109   Vdbe *p = (Vdbe *)pStmt;
1110   if( p ){
1111     assert( p->db!=0 );
1112     assert( sqlite3_mutex_held(p->db->mutex) );
1113     p->rc = sqlite3ApiExit(p->db, p->rc);
1114     sqlite3_mutex_leave(p->db->mutex);
1115   }
1116 }
1117 
1118 /**************************** sqlite3_column_  *******************************
1119 ** The following routines are used to access elements of the current row
1120 ** in the result set.
1121 */
1122 const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){
1123   const void *val;
1124   val = sqlite3_value_blob( columnMem(pStmt,i) );
1125   /* Even though there is no encoding conversion, value_blob() might
1126   ** need to call malloc() to expand the result of a zeroblob()
1127   ** expression.
1128   */
1129   columnMallocFailure(pStmt);
1130   return val;
1131 }
1132 int sqlite3_column_bytes(sqlite3_stmt *pStmt, int i){
1133   int val = sqlite3_value_bytes( columnMem(pStmt,i) );
1134   columnMallocFailure(pStmt);
1135   return val;
1136 }
1137 int sqlite3_column_bytes16(sqlite3_stmt *pStmt, int i){
1138   int val = sqlite3_value_bytes16( columnMem(pStmt,i) );
1139   columnMallocFailure(pStmt);
1140   return val;
1141 }
1142 double sqlite3_column_double(sqlite3_stmt *pStmt, int i){
1143   double val = sqlite3_value_double( columnMem(pStmt,i) );
1144   columnMallocFailure(pStmt);
1145   return val;
1146 }
1147 int sqlite3_column_int(sqlite3_stmt *pStmt, int i){
1148   int val = sqlite3_value_int( columnMem(pStmt,i) );
1149   columnMallocFailure(pStmt);
1150   return val;
1151 }
1152 sqlite_int64 sqlite3_column_int64(sqlite3_stmt *pStmt, int i){
1153   sqlite_int64 val = sqlite3_value_int64( columnMem(pStmt,i) );
1154   columnMallocFailure(pStmt);
1155   return val;
1156 }
1157 const unsigned char *sqlite3_column_text(sqlite3_stmt *pStmt, int i){
1158   const unsigned char *val = sqlite3_value_text( columnMem(pStmt,i) );
1159   columnMallocFailure(pStmt);
1160   return val;
1161 }
1162 sqlite3_value *sqlite3_column_value(sqlite3_stmt *pStmt, int i){
1163   Mem *pOut = columnMem(pStmt, i);
1164   if( pOut->flags&MEM_Static ){
1165     pOut->flags &= ~MEM_Static;
1166     pOut->flags |= MEM_Ephem;
1167   }
1168   columnMallocFailure(pStmt);
1169   return (sqlite3_value *)pOut;
1170 }
1171 #ifndef SQLITE_OMIT_UTF16
1172 const void *sqlite3_column_text16(sqlite3_stmt *pStmt, int i){
1173   const void *val = sqlite3_value_text16( columnMem(pStmt,i) );
1174   columnMallocFailure(pStmt);
1175   return val;
1176 }
1177 #endif /* SQLITE_OMIT_UTF16 */
1178 int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
1179   int iType = sqlite3_value_type( columnMem(pStmt,i) );
1180   columnMallocFailure(pStmt);
1181   return iType;
1182 }
1183 
1184 /*
1185 ** Convert the N-th element of pStmt->pColName[] into a string using
1186 ** xFunc() then return that string.  If N is out of range, return 0.
1187 **
1188 ** There are up to 5 names for each column.  useType determines which
1189 ** name is returned.  Here are the names:
1190 **
1191 **    0      The column name as it should be displayed for output
1192 **    1      The datatype name for the column
1193 **    2      The name of the database that the column derives from
1194 **    3      The name of the table that the column derives from
1195 **    4      The name of the table column that the result column derives from
1196 **
1197 ** If the result is not a simple column reference (if it is an expression
1198 ** or a constant) then useTypes 2, 3, and 4 return NULL.
1199 */
1200 static const void *columnName(
1201   sqlite3_stmt *pStmt,     /* The statement */
1202   int N,                   /* Which column to get the name for */
1203   int useUtf16,            /* True to return the name as UTF16 */
1204   int useType              /* What type of name */
1205 ){
1206   const void *ret;
1207   Vdbe *p;
1208   int n;
1209   sqlite3 *db;
1210 #ifdef SQLITE_ENABLE_API_ARMOR
1211   if( pStmt==0 ){
1212     (void)SQLITE_MISUSE_BKPT;
1213     return 0;
1214   }
1215 #endif
1216   ret = 0;
1217   p = (Vdbe *)pStmt;
1218   db = p->db;
1219   assert( db!=0 );
1220   n = sqlite3_column_count(pStmt);
1221   if( N<n && N>=0 ){
1222     N += useType*n;
1223     sqlite3_mutex_enter(db->mutex);
1224     assert( db->mallocFailed==0 );
1225 #ifndef SQLITE_OMIT_UTF16
1226     if( useUtf16 ){
1227       ret = sqlite3_value_text16((sqlite3_value*)&p->aColName[N]);
1228     }else
1229 #endif
1230     {
1231       ret = sqlite3_value_text((sqlite3_value*)&p->aColName[N]);
1232     }
1233     /* A malloc may have failed inside of the _text() call. If this
1234     ** is the case, clear the mallocFailed flag and return NULL.
1235     */
1236     if( db->mallocFailed ){
1237       sqlite3OomClear(db);
1238       ret = 0;
1239     }
1240     sqlite3_mutex_leave(db->mutex);
1241   }
1242   return ret;
1243 }
1244 
1245 /*
1246 ** Return the name of the Nth column of the result set returned by SQL
1247 ** statement pStmt.
1248 */
1249 const char *sqlite3_column_name(sqlite3_stmt *pStmt, int N){
1250   return columnName(pStmt, N, 0, COLNAME_NAME);
1251 }
1252 #ifndef SQLITE_OMIT_UTF16
1253 const void *sqlite3_column_name16(sqlite3_stmt *pStmt, int N){
1254   return columnName(pStmt, N, 1, COLNAME_NAME);
1255 }
1256 #endif
1257 
1258 /*
1259 ** Constraint:  If you have ENABLE_COLUMN_METADATA then you must
1260 ** not define OMIT_DECLTYPE.
1261 */
1262 #if defined(SQLITE_OMIT_DECLTYPE) && defined(SQLITE_ENABLE_COLUMN_METADATA)
1263 # error "Must not define both SQLITE_OMIT_DECLTYPE \
1264          and SQLITE_ENABLE_COLUMN_METADATA"
1265 #endif
1266 
1267 #ifndef SQLITE_OMIT_DECLTYPE
1268 /*
1269 ** Return the column declaration type (if applicable) of the 'i'th column
1270 ** of the result set of SQL statement pStmt.
1271 */
1272 const char *sqlite3_column_decltype(sqlite3_stmt *pStmt, int N){
1273   return columnName(pStmt, N, 0, COLNAME_DECLTYPE);
1274 }
1275 #ifndef SQLITE_OMIT_UTF16
1276 const void *sqlite3_column_decltype16(sqlite3_stmt *pStmt, int N){
1277   return columnName(pStmt, N, 1, COLNAME_DECLTYPE);
1278 }
1279 #endif /* SQLITE_OMIT_UTF16 */
1280 #endif /* SQLITE_OMIT_DECLTYPE */
1281 
1282 #ifdef SQLITE_ENABLE_COLUMN_METADATA
1283 /*
1284 ** Return the name of the database from which a result column derives.
1285 ** NULL is returned if the result column is an expression or constant or
1286 ** anything else which is not an unambiguous reference to a database column.
1287 */
1288 const char *sqlite3_column_database_name(sqlite3_stmt *pStmt, int N){
1289   return columnName(pStmt, N, 0, COLNAME_DATABASE);
1290 }
1291 #ifndef SQLITE_OMIT_UTF16
1292 const void *sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N){
1293   return columnName(pStmt, N, 1, COLNAME_DATABASE);
1294 }
1295 #endif /* SQLITE_OMIT_UTF16 */
1296 
1297 /*
1298 ** Return the name of the table from which a result column derives.
1299 ** NULL is returned if the result column is an expression or constant or
1300 ** anything else which is not an unambiguous reference to a database column.
1301 */
1302 const char *sqlite3_column_table_name(sqlite3_stmt *pStmt, int N){
1303   return columnName(pStmt, N, 0, COLNAME_TABLE);
1304 }
1305 #ifndef SQLITE_OMIT_UTF16
1306 const void *sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N){
1307   return columnName(pStmt, N, 1, COLNAME_TABLE);
1308 }
1309 #endif /* SQLITE_OMIT_UTF16 */
1310 
1311 /*
1312 ** Return the name of the table column from which a result column derives.
1313 ** NULL is returned if the result column is an expression or constant or
1314 ** anything else which is not an unambiguous reference to a database column.
1315 */
1316 const char *sqlite3_column_origin_name(sqlite3_stmt *pStmt, int N){
1317   return columnName(pStmt, N, 0, COLNAME_COLUMN);
1318 }
1319 #ifndef SQLITE_OMIT_UTF16
1320 const void *sqlite3_column_origin_name16(sqlite3_stmt *pStmt, int N){
1321   return columnName(pStmt, N, 1, COLNAME_COLUMN);
1322 }
1323 #endif /* SQLITE_OMIT_UTF16 */
1324 #endif /* SQLITE_ENABLE_COLUMN_METADATA */
1325 
1326 
1327 /******************************* sqlite3_bind_  ***************************
1328 **
1329 ** Routines used to attach values to wildcards in a compiled SQL statement.
1330 */
1331 /*
1332 ** Unbind the value bound to variable i in virtual machine p. This is the
1333 ** the same as binding a NULL value to the column. If the "i" parameter is
1334 ** out of range, then SQLITE_RANGE is returned. Othewise SQLITE_OK.
1335 **
1336 ** A successful evaluation of this routine acquires the mutex on p.
1337 ** the mutex is released if any kind of error occurs.
1338 **
1339 ** The error code stored in database p->db is overwritten with the return
1340 ** value in any case.
1341 */
1342 static int vdbeUnbind(Vdbe *p, int i){
1343   Mem *pVar;
1344   if( vdbeSafetyNotNull(p) ){
1345     return SQLITE_MISUSE_BKPT;
1346   }
1347   sqlite3_mutex_enter(p->db->mutex);
1348   if( p->iVdbeMagic!=VDBE_MAGIC_RUN || p->pc>=0 ){
1349     sqlite3Error(p->db, SQLITE_MISUSE);
1350     sqlite3_mutex_leave(p->db->mutex);
1351     sqlite3_log(SQLITE_MISUSE,
1352         "bind on a busy prepared statement: [%s]", p->zSql);
1353     return SQLITE_MISUSE_BKPT;
1354   }
1355   if( i<1 || i>p->nVar ){
1356     sqlite3Error(p->db, SQLITE_RANGE);
1357     sqlite3_mutex_leave(p->db->mutex);
1358     return SQLITE_RANGE;
1359   }
1360   i--;
1361   pVar = &p->aVar[i];
1362   sqlite3VdbeMemRelease(pVar);
1363   pVar->flags = MEM_Null;
1364   p->db->errCode = SQLITE_OK;
1365 
1366   /* If the bit corresponding to this variable in Vdbe.expmask is set, then
1367   ** binding a new value to this variable invalidates the current query plan.
1368   **
1369   ** IMPLEMENTATION-OF: R-57496-20354 If the specific value bound to a host
1370   ** parameter in the WHERE clause might influence the choice of query plan
1371   ** for a statement, then the statement will be automatically recompiled,
1372   ** as if there had been a schema change, on the first sqlite3_step() call
1373   ** following any change to the bindings of that parameter.
1374   */
1375   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || p->expmask==0 );
1376   if( p->expmask!=0 && (p->expmask & (i>=31 ? 0x80000000 : (u32)1<<i))!=0 ){
1377     p->expired = 1;
1378   }
1379   return SQLITE_OK;
1380 }
1381 
1382 /*
1383 ** Bind a text or BLOB value.
1384 */
1385 static int bindText(
1386   sqlite3_stmt *pStmt,   /* The statement to bind against */
1387   int i,                 /* Index of the parameter to bind */
1388   const void *zData,     /* Pointer to the data to be bound */
1389   i64 nData,             /* Number of bytes of data to be bound */
1390   void (*xDel)(void*),   /* Destructor for the data */
1391   u8 encoding            /* Encoding for the data */
1392 ){
1393   Vdbe *p = (Vdbe *)pStmt;
1394   Mem *pVar;
1395   int rc;
1396 
1397   rc = vdbeUnbind(p, i);
1398   if( rc==SQLITE_OK ){
1399     if( zData!=0 ){
1400       pVar = &p->aVar[i-1];
1401       rc = sqlite3VdbeMemSetStr(pVar, zData, nData, encoding, xDel);
1402       if( rc==SQLITE_OK && encoding!=0 ){
1403         rc = sqlite3VdbeChangeEncoding(pVar, ENC(p->db));
1404       }
1405       if( rc ){
1406         sqlite3Error(p->db, rc);
1407         rc = sqlite3ApiExit(p->db, rc);
1408       }
1409     }
1410     sqlite3_mutex_leave(p->db->mutex);
1411   }else if( xDel!=SQLITE_STATIC && xDel!=SQLITE_TRANSIENT ){
1412     xDel((void*)zData);
1413   }
1414   return rc;
1415 }
1416 
1417 
1418 /*
1419 ** Bind a blob value to an SQL statement variable.
1420 */
1421 int sqlite3_bind_blob(
1422   sqlite3_stmt *pStmt,
1423   int i,
1424   const void *zData,
1425   int nData,
1426   void (*xDel)(void*)
1427 ){
1428 #ifdef SQLITE_ENABLE_API_ARMOR
1429   if( nData<0 ) return SQLITE_MISUSE_BKPT;
1430 #endif
1431   return bindText(pStmt, i, zData, nData, xDel, 0);
1432 }
1433 int sqlite3_bind_blob64(
1434   sqlite3_stmt *pStmt,
1435   int i,
1436   const void *zData,
1437   sqlite3_uint64 nData,
1438   void (*xDel)(void*)
1439 ){
1440   assert( xDel!=SQLITE_DYNAMIC );
1441   return bindText(pStmt, i, zData, nData, xDel, 0);
1442 }
1443 int sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){
1444   int rc;
1445   Vdbe *p = (Vdbe *)pStmt;
1446   rc = vdbeUnbind(p, i);
1447   if( rc==SQLITE_OK ){
1448     sqlite3VdbeMemSetDouble(&p->aVar[i-1], rValue);
1449     sqlite3_mutex_leave(p->db->mutex);
1450   }
1451   return rc;
1452 }
1453 int sqlite3_bind_int(sqlite3_stmt *p, int i, int iValue){
1454   return sqlite3_bind_int64(p, i, (i64)iValue);
1455 }
1456 int sqlite3_bind_int64(sqlite3_stmt *pStmt, int i, sqlite_int64 iValue){
1457   int rc;
1458   Vdbe *p = (Vdbe *)pStmt;
1459   rc = vdbeUnbind(p, i);
1460   if( rc==SQLITE_OK ){
1461     sqlite3VdbeMemSetInt64(&p->aVar[i-1], iValue);
1462     sqlite3_mutex_leave(p->db->mutex);
1463   }
1464   return rc;
1465 }
1466 int sqlite3_bind_null(sqlite3_stmt *pStmt, int i){
1467   int rc;
1468   Vdbe *p = (Vdbe*)pStmt;
1469   rc = vdbeUnbind(p, i);
1470   if( rc==SQLITE_OK ){
1471     sqlite3_mutex_leave(p->db->mutex);
1472   }
1473   return rc;
1474 }
1475 int sqlite3_bind_pointer(
1476   sqlite3_stmt *pStmt,
1477   int i,
1478   void *pPtr,
1479   const char *zPTtype,
1480   void (*xDestructor)(void*)
1481 ){
1482   int rc;
1483   Vdbe *p = (Vdbe*)pStmt;
1484   rc = vdbeUnbind(p, i);
1485   if( rc==SQLITE_OK ){
1486     sqlite3VdbeMemSetPointer(&p->aVar[i-1], pPtr, zPTtype, xDestructor);
1487     sqlite3_mutex_leave(p->db->mutex);
1488   }else if( xDestructor ){
1489     xDestructor(pPtr);
1490   }
1491   return rc;
1492 }
1493 int sqlite3_bind_text(
1494   sqlite3_stmt *pStmt,
1495   int i,
1496   const char *zData,
1497   int nData,
1498   void (*xDel)(void*)
1499 ){
1500   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF8);
1501 }
1502 int sqlite3_bind_text64(
1503   sqlite3_stmt *pStmt,
1504   int i,
1505   const char *zData,
1506   sqlite3_uint64 nData,
1507   void (*xDel)(void*),
1508   unsigned char enc
1509 ){
1510   assert( xDel!=SQLITE_DYNAMIC );
1511   if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;
1512   return bindText(pStmt, i, zData, nData, xDel, enc);
1513 }
1514 #ifndef SQLITE_OMIT_UTF16
1515 int sqlite3_bind_text16(
1516   sqlite3_stmt *pStmt,
1517   int i,
1518   const void *zData,
1519   int nData,
1520   void (*xDel)(void*)
1521 ){
1522   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF16NATIVE);
1523 }
1524 #endif /* SQLITE_OMIT_UTF16 */
1525 int sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_value *pValue){
1526   int rc;
1527   switch( sqlite3_value_type((sqlite3_value*)pValue) ){
1528     case SQLITE_INTEGER: {
1529       rc = sqlite3_bind_int64(pStmt, i, pValue->u.i);
1530       break;
1531     }
1532     case SQLITE_FLOAT: {
1533       rc = sqlite3_bind_double(pStmt, i, pValue->u.r);
1534       break;
1535     }
1536     case SQLITE_BLOB: {
1537       if( pValue->flags & MEM_Zero ){
1538         rc = sqlite3_bind_zeroblob(pStmt, i, pValue->u.nZero);
1539       }else{
1540         rc = sqlite3_bind_blob(pStmt, i, pValue->z, pValue->n,SQLITE_TRANSIENT);
1541       }
1542       break;
1543     }
1544     case SQLITE_TEXT: {
1545       rc = bindText(pStmt,i,  pValue->z, pValue->n, SQLITE_TRANSIENT,
1546                               pValue->enc);
1547       break;
1548     }
1549     default: {
1550       rc = sqlite3_bind_null(pStmt, i);
1551       break;
1552     }
1553   }
1554   return rc;
1555 }
1556 int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
1557   int rc;
1558   Vdbe *p = (Vdbe *)pStmt;
1559   rc = vdbeUnbind(p, i);
1560   if( rc==SQLITE_OK ){
1561 #ifndef SQLITE_OMIT_INCRBLOB
1562     sqlite3VdbeMemSetZeroBlob(&p->aVar[i-1], n);
1563 #else
1564     rc = sqlite3VdbeMemSetZeroBlob(&p->aVar[i-1], n);
1565 #endif
1566     sqlite3_mutex_leave(p->db->mutex);
1567   }
1568   return rc;
1569 }
1570 int sqlite3_bind_zeroblob64(sqlite3_stmt *pStmt, int i, sqlite3_uint64 n){
1571   int rc;
1572   Vdbe *p = (Vdbe *)pStmt;
1573   sqlite3_mutex_enter(p->db->mutex);
1574   if( n>(u64)p->db->aLimit[SQLITE_LIMIT_LENGTH] ){
1575     rc = SQLITE_TOOBIG;
1576   }else{
1577     assert( (n & 0x7FFFFFFF)==n );
1578     rc = sqlite3_bind_zeroblob(pStmt, i, n);
1579   }
1580   rc = sqlite3ApiExit(p->db, rc);
1581   sqlite3_mutex_leave(p->db->mutex);
1582   return rc;
1583 }
1584 
1585 /*
1586 ** Return the number of wildcards that can be potentially bound to.
1587 ** This routine is added to support DBD::SQLite.
1588 */
1589 int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
1590   Vdbe *p = (Vdbe*)pStmt;
1591   return p ? p->nVar : 0;
1592 }
1593 
1594 /*
1595 ** Return the name of a wildcard parameter.  Return NULL if the index
1596 ** is out of range or if the wildcard is unnamed.
1597 **
1598 ** The result is always UTF-8.
1599 */
1600 const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
1601   Vdbe *p = (Vdbe*)pStmt;
1602   if( p==0 ) return 0;
1603   return sqlite3VListNumToName(p->pVList, i);
1604 }
1605 
1606 /*
1607 ** Given a wildcard parameter name, return the index of the variable
1608 ** with that name.  If there is no variable with the given name,
1609 ** return 0.
1610 */
1611 int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nName){
1612   if( p==0 || zName==0 ) return 0;
1613   return sqlite3VListNameToNum(p->pVList, zName, nName);
1614 }
1615 int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
1616   return sqlite3VdbeParameterIndex((Vdbe*)pStmt, zName, sqlite3Strlen30(zName));
1617 }
1618 
1619 /*
1620 ** Transfer all bindings from the first statement over to the second.
1621 */
1622 int sqlite3TransferBindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
1623   Vdbe *pFrom = (Vdbe*)pFromStmt;
1624   Vdbe *pTo = (Vdbe*)pToStmt;
1625   int i;
1626   assert( pTo->db==pFrom->db );
1627   assert( pTo->nVar==pFrom->nVar );
1628   sqlite3_mutex_enter(pTo->db->mutex);
1629   for(i=0; i<pFrom->nVar; i++){
1630     sqlite3VdbeMemMove(&pTo->aVar[i], &pFrom->aVar[i]);
1631   }
1632   sqlite3_mutex_leave(pTo->db->mutex);
1633   return SQLITE_OK;
1634 }
1635 
1636 #ifndef SQLITE_OMIT_DEPRECATED
1637 /*
1638 ** Deprecated external interface.  Internal/core SQLite code
1639 ** should call sqlite3TransferBindings.
1640 **
1641 ** It is misuse to call this routine with statements from different
1642 ** database connections.  But as this is a deprecated interface, we
1643 ** will not bother to check for that condition.
1644 **
1645 ** If the two statements contain a different number of bindings, then
1646 ** an SQLITE_ERROR is returned.  Nothing else can go wrong, so otherwise
1647 ** SQLITE_OK is returned.
1648 */
1649 int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
1650   Vdbe *pFrom = (Vdbe*)pFromStmt;
1651   Vdbe *pTo = (Vdbe*)pToStmt;
1652   if( pFrom->nVar!=pTo->nVar ){
1653     return SQLITE_ERROR;
1654   }
1655   assert( (pTo->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pTo->expmask==0 );
1656   if( pTo->expmask ){
1657     pTo->expired = 1;
1658   }
1659   assert( (pFrom->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pFrom->expmask==0 );
1660   if( pFrom->expmask ){
1661     pFrom->expired = 1;
1662   }
1663   return sqlite3TransferBindings(pFromStmt, pToStmt);
1664 }
1665 #endif
1666 
1667 /*
1668 ** Return the sqlite3* database handle to which the prepared statement given
1669 ** in the argument belongs.  This is the same database handle that was
1670 ** the first argument to the sqlite3_prepare() that was used to create
1671 ** the statement in the first place.
1672 */
1673 sqlite3 *sqlite3_db_handle(sqlite3_stmt *pStmt){
1674   return pStmt ? ((Vdbe*)pStmt)->db : 0;
1675 }
1676 
1677 /*
1678 ** Return true if the prepared statement is guaranteed to not modify the
1679 ** database.
1680 */
1681 int sqlite3_stmt_readonly(sqlite3_stmt *pStmt){
1682   return pStmt ? ((Vdbe*)pStmt)->readOnly : 1;
1683 }
1684 
1685 /*
1686 ** Return 1 if the statement is an EXPLAIN and return 2 if the
1687 ** statement is an EXPLAIN QUERY PLAN
1688 */
1689 int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt){
1690   return pStmt ? ((Vdbe*)pStmt)->explain : 0;
1691 }
1692 
1693 /*
1694 ** Return true if the prepared statement is in need of being reset.
1695 */
1696 int sqlite3_stmt_busy(sqlite3_stmt *pStmt){
1697   Vdbe *v = (Vdbe*)pStmt;
1698   return v!=0 && v->iVdbeMagic==VDBE_MAGIC_RUN && v->pc>=0;
1699 }
1700 
1701 /*
1702 ** Return a pointer to the next prepared statement after pStmt associated
1703 ** with database connection pDb.  If pStmt is NULL, return the first
1704 ** prepared statement for the database connection.  Return NULL if there
1705 ** are no more.
1706 */
1707 sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
1708   sqlite3_stmt *pNext;
1709 #ifdef SQLITE_ENABLE_API_ARMOR
1710   if( !sqlite3SafetyCheckOk(pDb) ){
1711     (void)SQLITE_MISUSE_BKPT;
1712     return 0;
1713   }
1714 #endif
1715   sqlite3_mutex_enter(pDb->mutex);
1716   if( pStmt==0 ){
1717     pNext = (sqlite3_stmt*)pDb->pVdbe;
1718   }else{
1719     pNext = (sqlite3_stmt*)((Vdbe*)pStmt)->pNext;
1720   }
1721   sqlite3_mutex_leave(pDb->mutex);
1722   return pNext;
1723 }
1724 
1725 /*
1726 ** Return the value of a status counter for a prepared statement
1727 */
1728 int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
1729   Vdbe *pVdbe = (Vdbe*)pStmt;
1730   u32 v;
1731 #ifdef SQLITE_ENABLE_API_ARMOR
1732   if( !pStmt
1733    || (op!=SQLITE_STMTSTATUS_MEMUSED && (op<0||op>=ArraySize(pVdbe->aCounter)))
1734   ){
1735     (void)SQLITE_MISUSE_BKPT;
1736     return 0;
1737   }
1738 #endif
1739   if( op==SQLITE_STMTSTATUS_MEMUSED ){
1740     sqlite3 *db = pVdbe->db;
1741     sqlite3_mutex_enter(db->mutex);
1742     v = 0;
1743     db->pnBytesFreed = (int*)&v;
1744     sqlite3VdbeClearObject(db, pVdbe);
1745     sqlite3DbFree(db, pVdbe);
1746     db->pnBytesFreed = 0;
1747     sqlite3_mutex_leave(db->mutex);
1748   }else{
1749     v = pVdbe->aCounter[op];
1750     if( resetFlag ) pVdbe->aCounter[op] = 0;
1751   }
1752   return (int)v;
1753 }
1754 
1755 /*
1756 ** Return the SQL associated with a prepared statement
1757 */
1758 const char *sqlite3_sql(sqlite3_stmt *pStmt){
1759   Vdbe *p = (Vdbe *)pStmt;
1760   return p ? p->zSql : 0;
1761 }
1762 
1763 /*
1764 ** Return the SQL associated with a prepared statement with
1765 ** bound parameters expanded.  Space to hold the returned string is
1766 ** obtained from sqlite3_malloc().  The caller is responsible for
1767 ** freeing the returned string by passing it to sqlite3_free().
1768 **
1769 ** The SQLITE_TRACE_SIZE_LIMIT puts an upper bound on the size of
1770 ** expanded bound parameters.
1771 */
1772 char *sqlite3_expanded_sql(sqlite3_stmt *pStmt){
1773 #ifdef SQLITE_OMIT_TRACE
1774   return 0;
1775 #else
1776   char *z = 0;
1777   const char *zSql = sqlite3_sql(pStmt);
1778   if( zSql ){
1779     Vdbe *p = (Vdbe *)pStmt;
1780     sqlite3_mutex_enter(p->db->mutex);
1781     z = sqlite3VdbeExpandSql(p, zSql);
1782     sqlite3_mutex_leave(p->db->mutex);
1783   }
1784   return z;
1785 #endif
1786 }
1787 
1788 #ifdef SQLITE_ENABLE_NORMALIZE
1789 /*
1790 ** Return the normalized SQL associated with a prepared statement.
1791 */
1792 const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt){
1793   Vdbe *p = (Vdbe *)pStmt;
1794   if( p==0 ) return 0;
1795   if( p->zNormSql==0 && ALWAYS(p->zSql!=0) ){
1796     sqlite3_mutex_enter(p->db->mutex);
1797     p->zNormSql = sqlite3Normalize(p, p->zSql);
1798     sqlite3_mutex_leave(p->db->mutex);
1799   }
1800   return p->zNormSql;
1801 }
1802 #endif /* SQLITE_ENABLE_NORMALIZE */
1803 
1804 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1805 /*
1806 ** Allocate and populate an UnpackedRecord structure based on the serialized
1807 ** record in nKey/pKey. Return a pointer to the new UnpackedRecord structure
1808 ** if successful, or a NULL pointer if an OOM error is encountered.
1809 */
1810 static UnpackedRecord *vdbeUnpackRecord(
1811   KeyInfo *pKeyInfo,
1812   int nKey,
1813   const void *pKey
1814 ){
1815   UnpackedRecord *pRet;           /* Return value */
1816 
1817   pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);
1818   if( pRet ){
1819     memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nKeyField+1));
1820     sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet);
1821   }
1822   return pRet;
1823 }
1824 
1825 /*
1826 ** This function is called from within a pre-update callback to retrieve
1827 ** a field of the row currently being updated or deleted.
1828 */
1829 int sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
1830   PreUpdate *p = db->pPreUpdate;
1831   Mem *pMem;
1832   int rc = SQLITE_OK;
1833 
1834   /* Test that this call is being made from within an SQLITE_DELETE or
1835   ** SQLITE_UPDATE pre-update callback, and that iIdx is within range. */
1836   if( !p || p->op==SQLITE_INSERT ){
1837     rc = SQLITE_MISUSE_BKPT;
1838     goto preupdate_old_out;
1839   }
1840   if( p->pPk ){
1841     iIdx = sqlite3TableColumnToIndex(p->pPk, iIdx);
1842   }
1843   if( iIdx>=p->pCsr->nField || iIdx<0 ){
1844     rc = SQLITE_RANGE;
1845     goto preupdate_old_out;
1846   }
1847 
1848   /* If the old.* record has not yet been loaded into memory, do so now. */
1849   if( p->pUnpacked==0 ){
1850     u32 nRec;
1851     u8 *aRec;
1852 
1853     assert( p->pCsr->eCurType==CURTYPE_BTREE );
1854     nRec = sqlite3BtreePayloadSize(p->pCsr->uc.pCursor);
1855     aRec = sqlite3DbMallocRaw(db, nRec);
1856     if( !aRec ) goto preupdate_old_out;
1857     rc = sqlite3BtreePayload(p->pCsr->uc.pCursor, 0, nRec, aRec);
1858     if( rc==SQLITE_OK ){
1859       p->pUnpacked = vdbeUnpackRecord(&p->keyinfo, nRec, aRec);
1860       if( !p->pUnpacked ) rc = SQLITE_NOMEM;
1861     }
1862     if( rc!=SQLITE_OK ){
1863       sqlite3DbFree(db, aRec);
1864       goto preupdate_old_out;
1865     }
1866     p->aRecord = aRec;
1867   }
1868 
1869   pMem = *ppValue = &p->pUnpacked->aMem[iIdx];
1870   if( iIdx==p->pTab->iPKey ){
1871     sqlite3VdbeMemSetInt64(pMem, p->iKey1);
1872   }else if( iIdx>=p->pUnpacked->nField ){
1873     *ppValue = (sqlite3_value *)columnNullValue();
1874   }else if( p->pTab->aCol[iIdx].affinity==SQLITE_AFF_REAL ){
1875     if( pMem->flags & (MEM_Int|MEM_IntReal) ){
1876       testcase( pMem->flags & MEM_Int );
1877       testcase( pMem->flags & MEM_IntReal );
1878       sqlite3VdbeMemRealify(pMem);
1879     }
1880   }
1881 
1882  preupdate_old_out:
1883   sqlite3Error(db, rc);
1884   return sqlite3ApiExit(db, rc);
1885 }
1886 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1887 
1888 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1889 /*
1890 ** This function is called from within a pre-update callback to retrieve
1891 ** the number of columns in the row being updated, deleted or inserted.
1892 */
1893 int sqlite3_preupdate_count(sqlite3 *db){
1894   PreUpdate *p = db->pPreUpdate;
1895   return (p ? p->keyinfo.nKeyField : 0);
1896 }
1897 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1898 
1899 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1900 /*
1901 ** This function is designed to be called from within a pre-update callback
1902 ** only. It returns zero if the change that caused the callback was made
1903 ** immediately by a user SQL statement. Or, if the change was made by a
1904 ** trigger program, it returns the number of trigger programs currently
1905 ** on the stack (1 for a top-level trigger, 2 for a trigger fired by a
1906 ** top-level trigger etc.).
1907 **
1908 ** For the purposes of the previous paragraph, a foreign key CASCADE, SET NULL
1909 ** or SET DEFAULT action is considered a trigger.
1910 */
1911 int sqlite3_preupdate_depth(sqlite3 *db){
1912   PreUpdate *p = db->pPreUpdate;
1913   return (p ? p->v->nFrame : 0);
1914 }
1915 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1916 
1917 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1918 /*
1919 ** This function is designed to be called from within a pre-update callback
1920 ** only.
1921 */
1922 int sqlite3_preupdate_blobwrite(sqlite3 *db){
1923   PreUpdate *p = db->pPreUpdate;
1924   return (p ? p->iBlobWrite : -1);
1925 }
1926 #endif
1927 
1928 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1929 /*
1930 ** This function is called from within a pre-update callback to retrieve
1931 ** a field of the row currently being updated or inserted.
1932 */
1933 int sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
1934   PreUpdate *p = db->pPreUpdate;
1935   int rc = SQLITE_OK;
1936   Mem *pMem;
1937 
1938   if( !p || p->op==SQLITE_DELETE ){
1939     rc = SQLITE_MISUSE_BKPT;
1940     goto preupdate_new_out;
1941   }
1942   if( p->pPk && p->op!=SQLITE_UPDATE ){
1943     iIdx = sqlite3TableColumnToIndex(p->pPk, iIdx);
1944   }
1945   if( iIdx>=p->pCsr->nField || iIdx<0 ){
1946     rc = SQLITE_RANGE;
1947     goto preupdate_new_out;
1948   }
1949 
1950   if( p->op==SQLITE_INSERT ){
1951     /* For an INSERT, memory cell p->iNewReg contains the serialized record
1952     ** that is being inserted. Deserialize it. */
1953     UnpackedRecord *pUnpack = p->pNewUnpacked;
1954     if( !pUnpack ){
1955       Mem *pData = &p->v->aMem[p->iNewReg];
1956       rc = ExpandBlob(pData);
1957       if( rc!=SQLITE_OK ) goto preupdate_new_out;
1958       pUnpack = vdbeUnpackRecord(&p->keyinfo, pData->n, pData->z);
1959       if( !pUnpack ){
1960         rc = SQLITE_NOMEM;
1961         goto preupdate_new_out;
1962       }
1963       p->pNewUnpacked = pUnpack;
1964     }
1965     pMem = &pUnpack->aMem[iIdx];
1966     if( iIdx==p->pTab->iPKey ){
1967       sqlite3VdbeMemSetInt64(pMem, p->iKey2);
1968     }else if( iIdx>=pUnpack->nField ){
1969       pMem = (sqlite3_value *)columnNullValue();
1970     }
1971   }else{
1972     /* For an UPDATE, memory cell (p->iNewReg+1+iIdx) contains the required
1973     ** value. Make a copy of the cell contents and return a pointer to it.
1974     ** It is not safe to return a pointer to the memory cell itself as the
1975     ** caller may modify the value text encoding.
1976     */
1977     assert( p->op==SQLITE_UPDATE );
1978     if( !p->aNew ){
1979       p->aNew = (Mem *)sqlite3DbMallocZero(db, sizeof(Mem) * p->pCsr->nField);
1980       if( !p->aNew ){
1981         rc = SQLITE_NOMEM;
1982         goto preupdate_new_out;
1983       }
1984     }
1985     assert( iIdx>=0 && iIdx<p->pCsr->nField );
1986     pMem = &p->aNew[iIdx];
1987     if( pMem->flags==0 ){
1988       if( iIdx==p->pTab->iPKey ){
1989         sqlite3VdbeMemSetInt64(pMem, p->iKey2);
1990       }else{
1991         rc = sqlite3VdbeMemCopy(pMem, &p->v->aMem[p->iNewReg+1+iIdx]);
1992         if( rc!=SQLITE_OK ) goto preupdate_new_out;
1993       }
1994     }
1995   }
1996   *ppValue = pMem;
1997 
1998  preupdate_new_out:
1999   sqlite3Error(db, rc);
2000   return sqlite3ApiExit(db, rc);
2001 }
2002 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2003 
2004 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
2005 /*
2006 ** Return status data for a single loop within query pStmt.
2007 */
2008 int sqlite3_stmt_scanstatus(
2009   sqlite3_stmt *pStmt,            /* Prepared statement being queried */
2010   int idx,                        /* Index of loop to report on */
2011   int iScanStatusOp,              /* Which metric to return */
2012   void *pOut                      /* OUT: Write the answer here */
2013 ){
2014   Vdbe *p = (Vdbe*)pStmt;
2015   ScanStatus *pScan;
2016   if( idx<0 || idx>=p->nScan ) return 1;
2017   pScan = &p->aScan[idx];
2018   switch( iScanStatusOp ){
2019     case SQLITE_SCANSTAT_NLOOP: {
2020       *(sqlite3_int64*)pOut = p->anExec[pScan->addrLoop];
2021       break;
2022     }
2023     case SQLITE_SCANSTAT_NVISIT: {
2024       *(sqlite3_int64*)pOut = p->anExec[pScan->addrVisit];
2025       break;
2026     }
2027     case SQLITE_SCANSTAT_EST: {
2028       double r = 1.0;
2029       LogEst x = pScan->nEst;
2030       while( x<100 ){
2031         x += 10;
2032         r *= 0.5;
2033       }
2034       *(double*)pOut = r*sqlite3LogEstToInt(x);
2035       break;
2036     }
2037     case SQLITE_SCANSTAT_NAME: {
2038       *(const char**)pOut = pScan->zName;
2039       break;
2040     }
2041     case SQLITE_SCANSTAT_EXPLAIN: {
2042       if( pScan->addrExplain ){
2043         *(const char**)pOut = p->aOp[ pScan->addrExplain ].p4.z;
2044       }else{
2045         *(const char**)pOut = 0;
2046       }
2047       break;
2048     }
2049     case SQLITE_SCANSTAT_SELECTID: {
2050       if( pScan->addrExplain ){
2051         *(int*)pOut = p->aOp[ pScan->addrExplain ].p1;
2052       }else{
2053         *(int*)pOut = -1;
2054       }
2055       break;
2056     }
2057     default: {
2058       return 1;
2059     }
2060   }
2061   return 0;
2062 }
2063 
2064 /*
2065 ** Zero all counters associated with the sqlite3_stmt_scanstatus() data.
2066 */
2067 void sqlite3_stmt_scanstatus_reset(sqlite3_stmt *pStmt){
2068   Vdbe *p = (Vdbe*)pStmt;
2069   memset(p->anExec, 0, p->nOp * sizeof(i64));
2070 }
2071 #endif /* SQLITE_ENABLE_STMT_SCANSTATUS */
2072