FCL/sf/os/persistentdata: comparison persistentstorage/sql/SQLite/vdbeapi.c

equal deleted inserted replaced

--1:000000000000
+:08ec8eefde2f
+/*
+** 2004 May 26
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains code use to implement APIs that are part of the
+** VDBE.
+**
+** $Id: vdbeapi.c,v 1.138 2008/08/02 03:50:39 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "vdbeInt.h"
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+/*
+** The following structure contains pointers to the end points of a
+** doubly-linked list of all compiled SQL statements that may be holding
+** buffers eligible for release when the sqlite3_release_memory() interface is
+** invoked. Access to this list is protected by the SQLITE_MUTEX_STATIC_LRU2
+** mutex.
+**
+** Statements are added to the end of this list when sqlite3_reset() is
+** called. They are removed either when sqlite3_step() or sqlite3_finalize()
+** is called. When statements are added to this list, the associated
+** register array (p->aMem[1..p->nMem]) may contain dynamic buffers that
+** can be freed using sqlite3VdbeReleaseMemory().
+**
+** When statements are added or removed from this list, the mutex
+** associated with the Vdbe being added or removed (Vdbe.db->mutex) is
+** already held. The LRU2 mutex is then obtained, blocking if necessary,
+** the linked-list pointers manipulated and the LRU2 mutex relinquished.
+*/
+struct StatementLruList {
+Vdbe *pFirst;
+Vdbe *pLast;
+};
+static struct StatementLruList sqlite3LruStatements;
+/*
+** Check that the list looks to be internally consistent. This is used
+** as part of an assert() statement as follows:
+**
+**   assert( stmtLruCheck() );
+*/
+#ifndef NDEBUG
+static int stmtLruCheck(){
+Vdbe *p;
+for(p=sqlite3LruStatements.pFirst; p; p=p->pLruNext){
+assert(p->pLruNext || p==sqlite3LruStatements.pLast);
+assert(!p->pLruNext || p->pLruNext->pLruPrev==p);
+assert(p->pLruPrev || p==sqlite3LruStatements.pFirst);
+assert(!p->pLruPrev || p->pLruPrev->pLruNext==p);
+}
+return 1;
+}
+#endif
+/*
+** Add vdbe p to the end of the statement lru list. It is assumed that
+** p is not already part of the list when this is called. The lru list
+** is protected by the SQLITE_MUTEX_STATIC_LRU mutex.
+*/
+static void stmtLruAdd(Vdbe *p){
+sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+if( p->pLruPrev || p->pLruNext || sqlite3LruStatements.pFirst==p ){
+sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+return;
+}
+assert( stmtLruCheck() );
+if( !sqlite3LruStatements.pFirst ){
+assert( !sqlite3LruStatements.pLast );
+sqlite3LruStatements.pFirst = p;
+sqlite3LruStatements.pLast = p;
+}else{
+assert( !sqlite3LruStatements.pLast->pLruNext );
+p->pLruPrev = sqlite3LruStatements.pLast;
+sqlite3LruStatements.pLast->pLruNext = p;
+sqlite3LruStatements.pLast = p;
+}
+assert( stmtLruCheck() );
+sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+}
+/*
+** Assuming the SQLITE_MUTEX_STATIC_LRU2 mutext is already held, remove
+** statement p from the least-recently-used statement list. If the
+** statement is not currently part of the list, this call is a no-op.
+*/
+static void stmtLruRemoveNomutex(Vdbe *p){
+if( p->pLruPrev || p->pLruNext || p==sqlite3LruStatements.pFirst ){
+assert( stmtLruCheck() );
+if( p->pLruNext ){
+p->pLruNext->pLruPrev = p->pLruPrev;
+}else{
+sqlite3LruStatements.pLast = p->pLruPrev;
+}
+if( p->pLruPrev ){
+p->pLruPrev->pLruNext = p->pLruNext;
+}else{
+sqlite3LruStatements.pFirst = p->pLruNext;
+}
+p->pLruNext = 0;
+p->pLruPrev = 0;
+assert( stmtLruCheck() );
+}
+}
+/*
+** Assuming the SQLITE_MUTEX_STATIC_LRU2 mutext is not held, remove
+** statement p from the least-recently-used statement list. If the
+** statement is not currently part of the list, this call is a no-op.
+*/
+static void stmtLruRemove(Vdbe *p){
+sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+stmtLruRemoveNomutex(p);
+sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+}
+/*
+** Try to release n bytes of memory by freeing buffers associated
+** with the memory registers of currently unused vdbes.
+*/
+int sqlite3VdbeReleaseMemory(int n){
+Vdbe *p;
+Vdbe *pNext;
+int nFree = 0;
+sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+for(p=sqlite3LruStatements.pFirst; p && nFree<n; p=pNext){
+pNext = p->pLruNext;
+/* For each statement handle in the lru list, attempt to obtain the
+** associated database mutex. If it cannot be obtained, continue
+** to the next statement handle. It is not possible to block on
+** the database mutex - that could cause deadlock.
+*/
+if( SQLITE_OK==sqlite3_mutex_try(p->db->mutex) ){
+nFree += sqlite3VdbeReleaseBuffers(p);
+stmtLruRemoveNomutex(p);
+sqlite3_mutex_leave(p->db->mutex);
+}
+}
+sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
+return nFree;
+}
+/*
+** Call sqlite3Reprepare() on the statement. Remove it from the
+** lru list before doing so, as Reprepare() will free all the
+** memory register buffers anyway.
+*/
+int vdbeReprepare(Vdbe *p){
+stmtLruRemove(p);
+return sqlite3Reprepare(p);
+}
+#else       /* !SQLITE_ENABLE_MEMORY_MANAGEMENT */
+#define stmtLruRemove(x)
+#define stmtLruAdd(x)
+#define vdbeReprepare(x) sqlite3Reprepare(x)
+#endif
+/*
+** Return TRUE (non-zero) of the statement supplied as an argument needs
+** to be recompiled.  A statement needs to be recompiled whenever the
+** execution environment changes in a way that would alter the program
+** that sqlite3_prepare() generates.  For example, if new functions or
+** collating sequences are registered or if an authorizer function is
+** added or changed.
+*/
+int sqlite3_expired(sqlite3_stmt *pStmt){
+Vdbe *p = (Vdbe*)pStmt;
+return p==0 || p->expired;
+}
+/*
+** The following routine destroys a virtual machine that is created by
+** the sqlite3_compile() routine. The integer returned is an SQLITE_
+** success/failure code that describes the result of executing the virtual
+** machine.
+**
+** This routine sets the error code and string returned by
+** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
+*/
+int sqlite3_finalize(sqlite3_stmt *pStmt){
+int rc;
+if( pStmt==0 ){
+rc = SQLITE_OK;
+}else{
+Vdbe *v = (Vdbe*)pStmt;
+#ifndef SQLITE_MUTEX_NOOP
+sqlite3_mutex *mutex = v->db->mutex;
+#endif
+sqlite3_mutex_enter(mutex);
+stmtLruRemove(v);
+rc = sqlite3VdbeFinalize(v);
+sqlite3_mutex_leave(mutex);
+}
+return rc;
+}
+/*
+** Terminate the current execution of an SQL statement and reset it
+** back to its starting state so that it can be reused. A success code from
+** the prior execution is returned.
+**
+** This routine sets the error code and string returned by
+** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
+*/
+int sqlite3_reset(sqlite3_stmt *pStmt){
+int rc;
+if( pStmt==0 ){
+rc = SQLITE_OK;
+}else{
+Vdbe *v = (Vdbe*)pStmt;
+sqlite3_mutex_enter(v->db->mutex);
+rc = sqlite3VdbeReset(v);
+stmtLruAdd(v);
+sqlite3VdbeMakeReady(v, -1, 0, 0, 0);
+assert( (rc & (v->db->errMask))==rc );
+sqlite3_mutex_leave(v->db->mutex);
+}
+return rc;
+}
+/*
+** Set all the parameters in the compiled SQL statement to NULL.
+*/
+int sqlite3_clear_bindings(sqlite3_stmt *pStmt){
+int i;
+int rc = SQLITE_OK;
+Vdbe *p = (Vdbe*)pStmt;
+#ifndef SQLITE_MUTEX_NOOP
+sqlite3_mutex *mutex = ((Vdbe*)pStmt)->db->mutex;
+#endif
+sqlite3_mutex_enter(mutex);
+for(i=0; i<p->nVar; i++){
+sqlite3VdbeMemRelease(&p->aVar[i]);
+p->aVar[i].flags = MEM_Null;
+}
+sqlite3_mutex_leave(mutex);
+return rc;
+}
+/**************************** sqlite3_value_  *******************************
+** The following routines extract information from a Mem or sqlite3_value
+** structure.
+*/
+const void *sqlite3_value_blob(sqlite3_value *pVal){
+Mem *p = (Mem*)pVal;
+if( p->flags & (MEM_Blob|MEM_Str) ){
+sqlite3VdbeMemExpandBlob(p);
+p->flags &= ~MEM_Str;
+p->flags |= MEM_Blob;
+return p->z;
+}else{
+return sqlite3_value_text(pVal);
+}
+}
+int sqlite3_value_bytes(sqlite3_value *pVal){
+return sqlite3ValueBytes(pVal, SQLITE_UTF8);
+}
+int sqlite3_value_bytes16(sqlite3_value *pVal){
+return sqlite3ValueBytes(pVal, SQLITE_UTF16NATIVE);
+}
+double sqlite3_value_double(sqlite3_value *pVal){
+return sqlite3VdbeRealValue((Mem*)pVal);
+}
+int sqlite3_value_int(sqlite3_value *pVal){
+return sqlite3VdbeIntValue((Mem*)pVal);
+}
+sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
+return sqlite3VdbeIntValue((Mem*)pVal);
+}
+const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
+return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_value_text16(sqlite3_value* pVal){
+return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
+}
+const void *sqlite3_value_text16be(sqlite3_value *pVal){
+return sqlite3ValueText(pVal, SQLITE_UTF16BE);
+}
+const void *sqlite3_value_text16le(sqlite3_value *pVal){
+return sqlite3ValueText(pVal, SQLITE_UTF16LE);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+int sqlite3_value_type(sqlite3_value* pVal){
+return pVal->type;
+}
+/**************************** sqlite3_result_  *******************************
+** The following routines are used by user-defined functions to specify
+** the function result.
+*/
+void sqlite3_result_blob(
+sqlite3_context *pCtx,
+const void *z,
+int n,
+void (*xDel)(void *)
+){
+assert( n>=0 );
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemSetStr(&pCtx->s, z, n, 0, xDel);
+}
+void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemSetDouble(&pCtx->s, rVal);
+}
+void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+pCtx->isError = SQLITE_ERROR;
+sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
+}
+#ifndef SQLITE_OMIT_UTF16
+void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+pCtx->isError = SQLITE_ERROR;
+sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
+}
+#endif
+void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemSetInt64(&pCtx->s, (i64)iVal);
+}
+void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemSetInt64(&pCtx->s, iVal);
+}
+void sqlite3_result_null(sqlite3_context *pCtx){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemSetNull(&pCtx->s);
+}
+void sqlite3_result_text(
+sqlite3_context *pCtx,
+const char *z,
+int n,
+void (*xDel)(void *)
+){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, xDel);
+}
+#ifndef SQLITE_OMIT_UTF16
+void sqlite3_result_text16(
+sqlite3_context *pCtx,
+const void *z,
+int n,
+void (*xDel)(void *)
+){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, xDel);
+}
+void sqlite3_result_text16be(
+sqlite3_context *pCtx,
+const void *z,
+int n,
+void (*xDel)(void *)
+){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16BE, xDel);
+}
+void sqlite3_result_text16le(
+sqlite3_context *pCtx,
+const void *z,
+int n,
+void (*xDel)(void *)
+){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16LE, xDel);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemCopy(&pCtx->s, pValue);
+}
+void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemSetZeroBlob(&pCtx->s, n);
+}
+void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
+pCtx->isError = errCode;
+}
+/* Force an SQLITE_TOOBIG error. */
+void sqlite3_result_error_toobig(sqlite3_context *pCtx){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+pCtx->isError = SQLITE_TOOBIG;
+sqlite3VdbeMemSetStr(&pCtx->s, "string or blob too big", -1,
+SQLITE_UTF8, SQLITE_STATIC);
+}
+/* An SQLITE_NOMEM error. */
+void sqlite3_result_error_nomem(sqlite3_context *pCtx){
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+sqlite3VdbeMemSetNull(&pCtx->s);
+pCtx->isError = SQLITE_NOMEM;
+pCtx->s.db->mallocFailed = 1;
+}
+/*
+** Execute the statement pStmt, either until a row of data is ready, the
+** statement is completely executed or an error occurs.
+**
+** This routine implements the bulk of the logic behind the sqlite_step()
+** API.  The only thing omitted is the automatic recompile if a
+** schema change has occurred.  That detail is handled by the
+** outer sqlite3_step() wrapper procedure.
+*/
+static int sqlite3Step(Vdbe *p){
+sqlite3 *db;
+int rc;
+assert(p);
+if( p->magic!=VDBE_MAGIC_RUN ){
+return SQLITE_MISUSE;
+}
+/* Assert that malloc() has not failed */
+db = p->db;
+assert( !db->mallocFailed );
+if( p->pc<=0 && p->expired ){
+if( p->rc==SQLITE_OK ){
+p->rc = SQLITE_SCHEMA;
+}
+rc = SQLITE_ERROR;
+goto end_of_step;
+}
+if( sqlite3SafetyOn(db) ){
+p->rc = SQLITE_MISUSE;
+return SQLITE_MISUSE;
+}
+if( p->pc<0 ){
+/* If there are no other statements currently running, then
+** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
+** from interrupting a statement that has not yet started.
+*/
+if( db->activeVdbeCnt==0 ){
+db->u1.isInterrupted = 0;
+}
+#ifndef SQLITE_OMIT_TRACE
+if( db->xProfile && !db->init.busy ){
+double rNow;
+sqlite3OsCurrentTime(db->pVfs, &rNow);
+p->startTime = (rNow - (int)rNow)*3600.0*24.0*1000000000.0;
+}
+#endif
+db->activeVdbeCnt++;
+p->pc = 0;
+stmtLruRemove(p);
+}
+#ifndef SQLITE_OMIT_EXPLAIN
+if( p->explain ){
+rc = sqlite3VdbeList(p);
+}else
+#endif /* SQLITE_OMIT_EXPLAIN */
+{
+rc = sqlite3VdbeExec(p);
+}
+if( sqlite3SafetyOff(db) ){
+rc = SQLITE_MISUSE;
+}
+#ifndef SQLITE_OMIT_TRACE
+/* Invoke the profile callback if there is one
+*/
+if( rc!=SQLITE_ROW && db->xProfile && !db->init.busy && p->nOp>0
+&& p->aOp[0].opcode==OP_Trace && p->aOp[0].p4.z!=0 ){
+double rNow;
+u64 elapseTime;
+sqlite3OsCurrentTime(db->pVfs, &rNow);
+elapseTime = (rNow - (int)rNow)*3600.0*24.0*1000000000.0 - p->startTime;
+db->xProfile(db->pProfileArg, p->aOp[0].p4.z, elapseTime);
+}
+#endif
+db->errCode = rc;
+/*sqlite3Error(p->db, rc, 0);*/
+p->rc = sqlite3ApiExit(p->db, p->rc);
+end_of_step:
+assert( (rc&0xff)==rc );
+if( p->zSql && (rc&0xff)<SQLITE_ROW ){
+/* This behavior occurs if sqlite3_prepare_v2() was used to build
+** the prepared statement.  Return error codes directly */
+p->db->errCode = p->rc;
+/* sqlite3Error(p->db, p->rc, 0); */
+return p->rc;
+}else{
+/* This is for legacy sqlite3_prepare() builds and when the code
+** is SQLITE_ROW or SQLITE_DONE */
+return rc;
+}
+}
+/*
+** This is the top-level implementation of sqlite3_step().  Call
+** sqlite3Step() to do most of the work.  If a schema error occurs,
+** call sqlite3Reprepare() and try again.
+*/
+#ifdef SQLITE_OMIT_PARSER
+int sqlite3_step(sqlite3_stmt *pStmt){
+int rc = SQLITE_MISUSE;
+if( pStmt ){
+Vdbe *v;
+v = (Vdbe*)pStmt;
+sqlite3_mutex_enter(v->db->mutex);
+rc = sqlite3Step(v);
+sqlite3_mutex_leave(v->db->mutex);
+}
+return rc;
+}
+#else
+int sqlite3_step(sqlite3_stmt *pStmt){
+int rc = SQLITE_MISUSE;
+if( pStmt ){
+int cnt = 0;
+Vdbe *v = (Vdbe*)pStmt;
+sqlite3 *db = v->db;
+sqlite3_mutex_enter(db->mutex);
+while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
+&& cnt++ < 5
+&& vdbeReprepare(v) ){
+sqlite3_reset(pStmt);
+v->expired = 0;
+}
+if( rc==SQLITE_SCHEMA && v->zSql && db->pErr ){
+/* This case occurs after failing to recompile an sql statement.
+** The error message from the SQL compiler has already been loaded
+** into the database handle. This block copies the error message
+** from the database handle into the statement and sets the statement
+** program counter to 0 to ensure that when the statement is
+** finalized or reset the parser error message is available via
+** sqlite3_errmsg() and sqlite3_errcode().
+*/
+const char *zErr = (const char *)sqlite3_value_text(db->pErr);
+sqlite3DbFree(db, v->zErrMsg);
+if( !db->mallocFailed ){
+v->zErrMsg = sqlite3DbStrDup(db, zErr);
+} else {
+v->zErrMsg = 0;
+v->rc = SQLITE_NOMEM;
+}
+}
+rc = sqlite3ApiExit(db, rc);
+sqlite3_mutex_leave(db->mutex);
+}
+return rc;
+}
+#endif
+/*
+** Extract the user data from a sqlite3_context structure and return a
+** pointer to it.
+*/
+void *sqlite3_user_data(sqlite3_context *p){
+assert( p && p->pFunc );
+return p->pFunc->pUserData;
+}
+/*
+** Extract the user data from a sqlite3_context structure and return a
+** pointer to it.
+*/
+sqlite3 *sqlite3_context_db_handle(sqlite3_context *p){
+assert( p && p->pFunc );
+return p->s.db;
+}
+/*
+** The following is the implementation of an SQL function that always
+** fails with an error message stating that the function is used in the
+** wrong context.  The sqlite3_overload_function() API might construct
+** SQL function that use this routine so that the functions will exist
+** for name resolution but are actually overloaded by the xFindFunction
+** method of virtual tables.
+*/
+void sqlite3InvalidFunction(
+sqlite3_context *context,  /* The function calling context */
+int argc,                  /* Number of arguments to the function */
+sqlite3_value **argv       /* Value of each argument */
+){
+const char *zName = context->pFunc->zName;
+char *zErr;
+zErr = sqlite3MPrintf(0,
+"unable to use function %s in the requested context", zName);
+sqlite3_result_error(context, zErr, -1);
+sqlite3_free(zErr);
+}
+/*
+** Allocate or return the aggregate context for a user function.  A new
+** context is allocated on the first call.  Subsequent calls return the
+** same context that was returned on prior calls.
+*/
+void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
+Mem *pMem;
+assert( p && p->pFunc && p->pFunc->xStep );
+assert( sqlite3_mutex_held(p->s.db->mutex) );
+pMem = p->pMem;
+if( (pMem->flags & MEM_Agg)==0 ){
+if( nByte==0 ){
+sqlite3VdbeMemReleaseExternal(pMem);
+pMem->flags = MEM_Null;
+pMem->z = 0;
+}else{
+sqlite3VdbeMemGrow(pMem, nByte, 0);
+pMem->flags = MEM_Agg;
+pMem->u.pDef = p->pFunc;
+if( pMem->z ){
+memset(pMem->z, 0, nByte);
+}
+}
+}
+return (void*)pMem->z;
+}
+/*
+** Return the auxilary data pointer, if any, for the iArg'th argument to
+** the user-function defined by pCtx.
+*/
+void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
+VdbeFunc *pVdbeFunc;
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+pVdbeFunc = pCtx->pVdbeFunc;
+if( !pVdbeFunc || iArg>=pVdbeFunc->nAux || iArg<0 ){
+return 0;
+}
+return pVdbeFunc->apAux[iArg].pAux;
+}
+/*
+** Set the auxilary data pointer and delete function, for the iArg'th
+** argument to the user-function defined by pCtx. Any previous value is
+** deleted by calling the delete function specified when it was set.
+*/
+void sqlite3_set_auxdata(
+sqlite3_context *pCtx,
+int iArg,
+void *pAux,
+void (*xDelete)(void*)
+){
+struct AuxData *pAuxData;
+VdbeFunc *pVdbeFunc;
+if( iArg<0 ) goto failed;
+assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+pVdbeFunc = pCtx->pVdbeFunc;
+if( !pVdbeFunc || pVdbeFunc->nAux<=iArg ){
+int nAux = (pVdbeFunc ? pVdbeFunc->nAux : 0);
+int nMalloc = sizeof(VdbeFunc) + sizeof(struct AuxData)*iArg;
+pVdbeFunc = sqlite3DbRealloc(pCtx->s.db, pVdbeFunc, nMalloc);
+if( !pVdbeFunc ){
+goto failed;
+}
+pCtx->pVdbeFunc = pVdbeFunc;
+memset(&pVdbeFunc->apAux[nAux], 0, sizeof(struct AuxData)*(iArg+1-nAux));
+pVdbeFunc->nAux = iArg+1;
+pVdbeFunc->pFunc = pCtx->pFunc;
+}
+pAuxData = &pVdbeFunc->apAux[iArg];
+if( pAuxData->pAux && pAuxData->xDelete ){
+pAuxData->xDelete(pAuxData->pAux);
+}
+pAuxData->pAux = pAux;
+pAuxData->xDelete = xDelete;
+return;
+failed:
+if( xDelete ){
+xDelete(pAux);
+}
+}
+/*
+** Return the number of times the Step function of a aggregate has been
+** called.
+**
+** This function is deprecated.  Do not use it for new code.  It is
+** provide only to avoid breaking legacy code.  New aggregate function
+** implementations should keep their own counts within their aggregate
+** context.
+*/
+int sqlite3_aggregate_count(sqlite3_context *p){
+assert( p && p->pFunc && p->pFunc->xStep );
+return p->pMem->n;
+}
+/*
+** Return the number of columns in the result set for the statement pStmt.
+*/
+int sqlite3_column_count(sqlite3_stmt *pStmt){
+Vdbe *pVm = (Vdbe *)pStmt;
+return pVm ? pVm->nResColumn : 0;
+}
+/*
+** Return the number of values available from the current row of the
+** currently executing statement pStmt.
+*/
+int sqlite3_data_count(sqlite3_stmt *pStmt){
+Vdbe *pVm = (Vdbe *)pStmt;
+if( pVm==0 || pVm->pResultSet==0 ) return 0;
+return pVm->nResColumn;
+}
+/*
+** Check to see if column iCol of the given statement is valid.  If
+** it is, return a pointer to the Mem for the value of that column.
+** If iCol is not valid, return a pointer to a Mem which has a value
+** of NULL.
+*/
+static Mem *columnMem(sqlite3_stmt *pStmt, int i){
+Vdbe *pVm;
+int vals;
+Mem *pOut;
+pVm = (Vdbe *)pStmt;
+if( pVm && pVm->pResultSet!=0 && i<pVm->nResColumn && i>=0 ){
+sqlite3_mutex_enter(pVm->db->mutex);
+vals = sqlite3_data_count(pStmt);
+pOut = &pVm->pResultSet[i];
+}else{
+static const Mem nullMem = {{0}, 0.0, 0, "", 0, MEM_Null, SQLITE_NULL, 0, 0, 0 };
+if( pVm->db ){
+sqlite3_mutex_enter(pVm->db->mutex);
+sqlite3Error(pVm->db, SQLITE_RANGE, 0);
+}
+pOut = (Mem*)&nullMem;
+}
+return pOut;
+}
+/*
+** This function is called after invoking an sqlite3_value_XXX function on a
+** column value (i.e. a value returned by evaluating an SQL expression in the
+** select list of a SELECT statement) that may cause a malloc() failure. If
+** malloc() has failed, the threads mallocFailed flag is cleared and the result
+** code of statement pStmt set to SQLITE_NOMEM.
+**
+** Specifically, this is called from within:
+**
+**     sqlite3_column_int()
+**     sqlite3_column_int64()
+**     sqlite3_column_text()
+**     sqlite3_column_text16()
+**     sqlite3_column_real()
+**     sqlite3_column_bytes()
+**     sqlite3_column_bytes16()
+**
+** But not for sqlite3_column_blob(), which never calls malloc().
+*/
+static void columnMallocFailure(sqlite3_stmt *pStmt)
+{
+/* If malloc() failed during an encoding conversion within an
+** sqlite3_column_XXX API, then set the return code of the statement to
+** SQLITE_NOMEM. The next call to _step() (if any) will return SQLITE_ERROR
+** and _finalize() will return NOMEM.
+*/
+Vdbe *p = (Vdbe *)pStmt;
+if( p ){
+p->rc = sqlite3ApiExit(p->db, p->rc);
+sqlite3_mutex_leave(p->db->mutex);
+}
+}
+/**************************** sqlite3_column_  *******************************
+** The following routines are used to access elements of the current row
+** in the result set.
+*/
+const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){
+const void *val;
+val = sqlite3_value_blob( columnMem(pStmt,i) );
+/* Even though there is no encoding conversion, value_blob() might
+** need to call malloc() to expand the result of a zeroblob()
+** expression.
+*/
+columnMallocFailure(pStmt);
+return val;
+}
+int sqlite3_column_bytes(sqlite3_stmt *pStmt, int i){
+int val = sqlite3_value_bytes( columnMem(pStmt,i) );
+columnMallocFailure(pStmt);
+return val;
+}
+int sqlite3_column_bytes16(sqlite3_stmt *pStmt, int i){
+int val = sqlite3_value_bytes16( columnMem(pStmt,i) );
+columnMallocFailure(pStmt);
+return val;
+}
+double sqlite3_column_double(sqlite3_stmt *pStmt, int i){
+double val = sqlite3_value_double( columnMem(pStmt,i) );
+columnMallocFailure(pStmt);
+return val;
+}
+int sqlite3_column_int(sqlite3_stmt *pStmt, int i){
+int val = sqlite3_value_int( columnMem(pStmt,i) );
+columnMallocFailure(pStmt);
+return val;
+}
+sqlite_int64 sqlite3_column_int64(sqlite3_stmt *pStmt, int i){
+sqlite_int64 val = sqlite3_value_int64( columnMem(pStmt,i) );
+columnMallocFailure(pStmt);
+return val;
+}
+const unsigned char *sqlite3_column_text(sqlite3_stmt *pStmt, int i){
+const unsigned char *val = sqlite3_value_text( columnMem(pStmt,i) );
+columnMallocFailure(pStmt);
+return val;
+}
+sqlite3_value *sqlite3_column_value(sqlite3_stmt *pStmt, int i){
+sqlite3_value *pOut = columnMem(pStmt, i);
+columnMallocFailure(pStmt);
+return pOut;
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_text16(sqlite3_stmt *pStmt, int i){
+const void *val = sqlite3_value_text16( columnMem(pStmt,i) );
+columnMallocFailure(pStmt);
+return val;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
+int iType = sqlite3_value_type( columnMem(pStmt,i) );
+columnMallocFailure(pStmt);
+return iType;
+}
+/* The following function is experimental and subject to change or
+** removal */
+/*int sqlite3_column_numeric_type(sqlite3_stmt *pStmt, int i){
+**  return sqlite3_value_numeric_type( columnMem(pStmt,i) );
+**}
+*/
+/*
+** Convert the N-th element of pStmt->pColName[] into a string using
+** xFunc() then return that string.  If N is out of range, return 0.
+**
+** There are up to 5 names for each column.  useType determines which
+** name is returned.  Here are the names:
+**
+**    0      The column name as it should be displayed for output
+**    1      The datatype name for the column
+**    2      The name of the database that the column derives from
+**    3      The name of the table that the column derives from
+**    4      The name of the table column that the result column derives from
+**
+** If the result is not a simple column reference (if it is an expression
+** or a constant) then useTypes 2, 3, and 4 return NULL.
+*/
+static const void *columnName(
+sqlite3_stmt *pStmt,
+int N,
+const void *(*xFunc)(Mem*),
+int useType
+){
+const void *ret = 0;
+Vdbe *p = (Vdbe *)pStmt;
+int n;
+if( p!=0 ){
+n = sqlite3_column_count(pStmt);
+if( N<n && N>=0 ){
+N += useType*n;
+sqlite3_mutex_enter(p->db->mutex);
+ret = xFunc(&p->aColName[N]);
+/* A malloc may have failed inside of the xFunc() call. If this
+** is the case, clear the mallocFailed flag and return NULL.
+*/
+if( p->db && p->db->mallocFailed ){
+p->db->mallocFailed = 0;
+ret = 0;
+}
+sqlite3_mutex_leave(p->db->mutex);
+}
+}
+return ret;
+}
+/*
+** Return the name of the Nth column of the result set returned by SQL
+** statement pStmt.
+*/
+const char *sqlite3_column_name(sqlite3_stmt *pStmt, int N){
+return columnName(
+pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_NAME);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_name16(sqlite3_stmt *pStmt, int N){
+return columnName(
+pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_NAME);
+}
+#endif
+/*
+** Constraint:  If you have ENABLE_COLUMN_METADATA then you must
+** not define OMIT_DECLTYPE.
+*/
+#if defined(SQLITE_OMIT_DECLTYPE) && defined(SQLITE_ENABLE_COLUMN_METADATA)
+# error "Must not define both SQLITE_OMIT_DECLTYPE \
+and SQLITE_ENABLE_COLUMN_METADATA"
+#endif
+#ifndef SQLITE_OMIT_DECLTYPE
+/*
+** Return the column declaration type (if applicable) of the 'i'th column
+** of the result set of SQL statement pStmt.
+*/
+const char *sqlite3_column_decltype(sqlite3_stmt *pStmt, int N){
+return columnName(
+pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_DECLTYPE);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_decltype16(sqlite3_stmt *pStmt, int N){
+return columnName(
+pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_DECLTYPE);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+#endif /* SQLITE_OMIT_DECLTYPE */
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+/*
+** Return the name of the database from which a result column derives.
+** NULL is returned if the result column is an expression or constant or
+** anything else which is not an unabiguous reference to a database column.
+*/
+const char *sqlite3_column_database_name(sqlite3_stmt *pStmt, int N){
+return columnName(
+pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_DATABASE);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N){
+return columnName(
+pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_DATABASE);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+/*
+** Return the name of the table from which a result column derives.
+** NULL is returned if the result column is an expression or constant or
+** anything else which is not an unabiguous reference to a database column.
+*/
+const char *sqlite3_column_table_name(sqlite3_stmt *pStmt, int N){
+return columnName(
+pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_TABLE);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N){
+return columnName(
+pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_TABLE);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+/*
+** Return the name of the table column from which a result column derives.
+** NULL is returned if the result column is an expression or constant or
+** anything else which is not an unabiguous reference to a database column.
+*/
+const char *sqlite3_column_origin_name(sqlite3_stmt *pStmt, int N){
+return columnName(
+pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_COLUMN);
+}
+#ifndef SQLITE_OMIT_UTF16
+const void *sqlite3_column_origin_name16(sqlite3_stmt *pStmt, int N){
+return columnName(
+pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_COLUMN);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+#endif /* SQLITE_ENABLE_COLUMN_METADATA */
+/******************************* sqlite3_bind_  ***************************
+**
+** Routines used to attach values to wildcards in a compiled SQL statement.
+*/
+/*
+** Unbind the value bound to variable i in virtual machine p. This is the
+** the same as binding a NULL value to the column. If the "i" parameter is
+** out of range, then SQLITE_RANGE is returned. Othewise SQLITE_OK.
+**
+** The error code stored in database p->db is overwritten with the return
+** value in any case.
+*/
+static int vdbeUnbind(Vdbe *p, int i){
+Mem *pVar;
+if( p==0 || p->magic!=VDBE_MAGIC_RUN || p->pc>=0 ){
+if( p ) sqlite3Error(p->db, SQLITE_MISUSE, 0);
+return SQLITE_MISUSE;
+}
+if( i<1 || i>p->nVar ){
+sqlite3Error(p->db, SQLITE_RANGE, 0);
+return SQLITE_RANGE;
+}
+i--;
+pVar = &p->aVar[i];
+sqlite3VdbeMemRelease(pVar);
+pVar->flags = MEM_Null;
+sqlite3Error(p->db, SQLITE_OK, 0);
+return SQLITE_OK;
+}
+/*
+** Bind a text or BLOB value.
+*/
+static int bindText(
+sqlite3_stmt *pStmt,   /* The statement to bind against */
+int i,                 /* Index of the parameter to bind */
+const void *zData,     /* Pointer to the data to be bound */
+int nData,             /* Number of bytes of data to be bound */
+void (*xDel)(void*),   /* Destructor for the data */
+int encoding           /* Encoding for the data */
+){
+Vdbe *p = (Vdbe *)pStmt;
+Mem *pVar;
+int rc;
+if( p==0 ){
+return SQLITE_MISUSE;
+}
+sqlite3_mutex_enter(p->db->mutex);
+rc = vdbeUnbind(p, i);
+if( rc==SQLITE_OK && zData!=0 ){
+pVar = &p->aVar[i-1];
+rc = sqlite3VdbeMemSetStr(pVar, zData, nData, encoding, xDel);
+if( rc==SQLITE_OK && encoding!=0 ){
+rc = sqlite3VdbeChangeEncoding(pVar, ENC(p->db));
+}
+sqlite3Error(p->db, rc, 0);
+rc = sqlite3ApiExit(p->db, rc);
+}
+sqlite3_mutex_leave(p->db->mutex);
+return rc;
+}
+/*
+** Bind a blob value to an SQL statement variable.
+*/
+int sqlite3_bind_blob(
+sqlite3_stmt *pStmt,
+int i,
+const void *zData,
+int nData,
+void (*xDel)(void*)
+){
+return bindText(pStmt, i, zData, nData, xDel, 0);
+}
+int sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){
+int rc;
+Vdbe *p = (Vdbe *)pStmt;
+sqlite3_mutex_enter(p->db->mutex);
+rc = vdbeUnbind(p, i);
+if( rc==SQLITE_OK ){
+sqlite3VdbeMemSetDouble(&p->aVar[i-1], rValue);
+}
+sqlite3_mutex_leave(p->db->mutex);
+return rc;
+}
+int sqlite3_bind_int(sqlite3_stmt *p, int i, int iValue){
+return sqlite3_bind_int64(p, i, (i64)iValue);
+}
+int sqlite3_bind_int64(sqlite3_stmt *pStmt, int i, sqlite_int64 iValue){
+int rc;
+Vdbe *p = (Vdbe *)pStmt;
+sqlite3_mutex_enter(p->db->mutex);
+rc = vdbeUnbind(p, i);
+if( rc==SQLITE_OK ){
+sqlite3VdbeMemSetInt64(&p->aVar[i-1], iValue);
+}
+sqlite3_mutex_leave(p->db->mutex);
+return rc;
+}
+int sqlite3_bind_null(sqlite3_stmt *pStmt, int i){
+int rc;
+Vdbe *p = (Vdbe*)pStmt;
+sqlite3_mutex_enter(p->db->mutex);
+rc = vdbeUnbind(p, i);
+sqlite3_mutex_leave(p->db->mutex);
+return rc;
+}
+int sqlite3_bind_text(
+sqlite3_stmt *pStmt,
+int i,
+const char *zData,
+int nData,
+void (*xDel)(void*)
+){
+return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF8);
+}
+#ifndef SQLITE_OMIT_UTF16
+int sqlite3_bind_text16(
+sqlite3_stmt *pStmt,
+int i,
+const void *zData,
+int nData,
+void (*xDel)(void*)
+){
+return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF16NATIVE);
+}
+#endif /* SQLITE_OMIT_UTF16 */
+int sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_value *pValue){
+int rc;
+Vdbe *p = (Vdbe *)pStmt;
+sqlite3_mutex_enter(p->db->mutex);
+rc = vdbeUnbind(p, i);
+if( rc==SQLITE_OK ){
+rc = sqlite3VdbeMemCopy(&p->aVar[i-1], pValue);
+if( rc==SQLITE_OK ){
+rc = sqlite3VdbeChangeEncoding(&p->aVar[i-1], ENC(p->db));
+}
+}
+rc = sqlite3ApiExit(p->db, rc);
+sqlite3_mutex_leave(p->db->mutex);
+return rc;
+}
+int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
+int rc;
+Vdbe *p = (Vdbe *)pStmt;
+sqlite3_mutex_enter(p->db->mutex);
+rc = vdbeUnbind(p, i);
+if( rc==SQLITE_OK ){
+sqlite3VdbeMemSetZeroBlob(&p->aVar[i-1], n);
+}
+sqlite3_mutex_leave(p->db->mutex);
+return rc;
+}
+/*
+** Return the number of wildcards that can be potentially bound to.
+** This routine is added to support DBD::SQLite.
+*/
+int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
+Vdbe *p = (Vdbe*)pStmt;
+return p ? p->nVar : 0;
+}
+/*
+** Create a mapping from variable numbers to variable names
+** in the Vdbe.azVar[] array, if such a mapping does not already
+** exist.
+*/
+static void createVarMap(Vdbe *p){
+if( !p->okVar ){
+sqlite3_mutex_enter(p->db->mutex);
+if( !p->okVar ){
+int j;
+Op *pOp;
+for(j=0, pOp=p->aOp; j<p->nOp; j++, pOp++){
+if( pOp->opcode==OP_Variable ){
+assert( pOp->p1>0 && pOp->p1<=p->nVar );
+p->azVar[pOp->p1-1] = pOp->p4.z;
+}
+}
+p->okVar = 1;
+}
+sqlite3_mutex_leave(p->db->mutex);
+}
+}
+/*
+** Return the name of a wildcard parameter.  Return NULL if the index
+** is out of range or if the wildcard is unnamed.
+**
+** The result is always UTF-8.
+*/
+const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
+Vdbe *p = (Vdbe*)pStmt;
+if( p==0 || i<1 || i>p->nVar ){
+return 0;
+}
+createVarMap(p);
+return p->azVar[i-1];
+}
+/*
+** Given a wildcard parameter name, return the index of the variable
+** with that name.  If there is no variable with the given name,
+** return 0.
+*/
+int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
+Vdbe *p = (Vdbe*)pStmt;
+int i;
+if( p==0 ){
+return 0;
+}
+createVarMap(p);
+if( zName ){
+for(i=0; i<p->nVar; i++){
+const char *z = p->azVar[i];
+if( z && strcmp(z,zName)==0 ){
+return i+1;
+}
+}
+}
+return 0;
+}
+/*
+** Transfer all bindings from the first statement over to the second.
+** If the two statements contain a different number of bindings, then
+** an SQLITE_ERROR is returned.
+*/
+int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
+Vdbe *pFrom = (Vdbe*)pFromStmt;
+Vdbe *pTo = (Vdbe*)pToStmt;
+int i, rc = SQLITE_OK;
+if( (pFrom->magic!=VDBE_MAGIC_RUN && pFrom->magic!=VDBE_MAGIC_HALT)
+|| (pTo->magic!=VDBE_MAGIC_RUN && pTo->magic!=VDBE_MAGIC_HALT)
+|| pTo->db!=pFrom->db ){
+return SQLITE_MISUSE;
+}
+if( pFrom->nVar!=pTo->nVar ){
+return SQLITE_ERROR;
+}
+sqlite3_mutex_enter(pTo->db->mutex);
+for(i=0; rc==SQLITE_OK && i<pFrom->nVar; i++){
+sqlite3VdbeMemMove(&pTo->aVar[i], &pFrom->aVar[i]);
+}
+sqlite3_mutex_leave(pTo->db->mutex);
+assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
+return rc;
+}
+/*
+** Return the sqlite3* database handle to which the prepared statement given
+** in the argument belongs.  This is the same database handle that was
+** the first argument to the sqlite3_prepare() that was used to create
+** the statement in the first place.
+*/
+sqlite3 *sqlite3_db_handle(sqlite3_stmt *pStmt){
+return pStmt ? ((Vdbe*)pStmt)->db : 0;
+}
+/*
+** Return a pointer to the next prepared statement after pStmt associated
+** with database connection pDb.  If pStmt is NULL, return the first
+** prepared statement for the database connection.  Return NULL if there
+** are no more.
+*/
+sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
+sqlite3_stmt *pNext;
+sqlite3_mutex_enter(pDb->mutex);
+if( pStmt==0 ){
+pNext = (sqlite3_stmt*)pDb->pVdbe;
+}else{
+pNext = (sqlite3_stmt*)((Vdbe*)pStmt)->pNext;
+}
+sqlite3_mutex_leave(pDb->mutex);
+return pNext;
+}