forgotten commit. disabled until egl is adapted.

[AROS-Contrib.git] / sqlite3 / main.c

/* vi:set ts=4 sts=4 sw=4: */
/*
 * 2005 July 7, Markku Sukanen
 *  - modifying for AROS
 *
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/
/**
 * @file main.c
 * 
 * Main file for the SQLite library. The routines in this file implement the
 * programmer interface to the library. Routines in other files are for
 * internal use by SQLite and should not be accessed by users of the library.
 * 
 * */
/* $Id$ */
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
 * The following constant value is used by the SQLITE_BIGENDIAN and
 * SQLITE_LITTLEENDIAN macros.
 * */
const int sqlite3one = 1;

#ifndef SQLITE_OMIT_GLOBALRECOVER
/*
 * Linked list of all open database handles. This is used by the 
 * sqlite3_global_recover() function. Entries are added to the list by
 * openDatabase() and removed by sqlite3_close().
 * */
static sqlite3 *pDbList = 0;
#endif


#ifndef SQLITE_OMIT_UTF16
/*
 * Return the transient sqlite3_value object used for encoding conversions
 * during SQL compilation.
 * */
sqlite3_value *sqlite3GetTransientValue(sqlite3 *db)
{
        if( !db->pValue )
                db->pValue = sqlite3ValueNew();
        return db->pValue;
}
#endif


/*
 * The version of the library.
 * */
const char rcsid3[] = "@(#) \044Id: SQLite version " SQLITE_VERSION " $";
const char sqlite3_version[] = SQLITE_VERSION;
const char *sqlite3_libversion(void){ return sqlite3_version; }
int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }


/*
 * This is the default collating function named "BINARY" which is always
 * available.
 * */
static int binCollFunc(
                void *NotUsed,
                int nKey1, const void *pKey1,
                int nKey2, const void *pKey2
                )
{
        int rc, n;
        n = nKey1<nKey2 ? nKey1 : nKey2;
        rc = memcmp(pKey1, pKey2, n);
        if( rc==0 )
                rc = nKey1 - nKey2;
        return rc;
}


/*
 * Another built-in collating sequence: NOCASE.
 *
 * This collating sequence is intended to be used for "case independant
 * comparison". SQLite's knowledge of upper and lower case equivalents extends
 * only to the 26 characters used in the English language.
 *
 * At the moment there is only a UTF-8 implementation.
 * */
static int nocaseCollatingFunc(
                void *NotUsed,
                int nKey1, const void *pKey1,
                int nKey2, const void *pKey2
                )
{
        int r = sqlite3StrNICmp(
                        (const char *)pKey1, (const char *)pKey2,
                        (nKey1<nKey2)?nKey1:nKey2);
        if( 0==r )
                r = nKey1-nKey2;
        return r;
}


/*
 * Return the ROWID of the most recent insert.
 * */
sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db)
{
        return db->lastRowid;
}


/*
 * Return the number of changes in the most recent call to sqlite3_exec().
 * */
int sqlite3_changes(sqlite3 *db)
{
        return db->nChange;
}


/*
 * Return the number of changes since the database handle was opened.
 * */
int sqlite3_total_changes(sqlite3 *db)
{
        return db->nTotalChange;
}


/*
 * Close an existing SQLite database.
 * */
int sqlite3_close(sqlite3 *db)
{
        HashElem *i;
        int j;
        
        if( !db )
                return SQLITE_OK;
        
        if( sqlite3SafetyCheck(db) )
                return SQLITE_MISUSE;
        
#ifdef SQLITE_SSE
        sqlite3_finalize(db->pFetch);
#endif 

        /* If there are any outstanding VMs, return SQLITE_BUSY. */
        if( db->pVdbe )
        {
                sqlite3Error(db, SQLITE_BUSY,
                                "Unable to close due to unfinalised statements");
                return SQLITE_BUSY;
        }
        assert( !sqlite3SafetyCheck(db) );

        /*
         * FIX ME: db->magic may be set to SQLITE_MAGIC_CLOSED if the database
         * cannot be opened for some reason. So this routine needs to run in that
         * case. But maybe there should be an extra magic value for the "failed to
         * open" state.
         * */
        if( db->magic!=SQLITE_MAGIC_CLOSED && sqlite3SafetyOn(db) )
        {
                /* printf("DID NOT CLOSE\n"); fflush(stdout); */
                return SQLITE_ERROR;
        }
        
        for(j=0; j<db->nDb; j++)
        {
                struct Db *pDb = &db->aDb[j];
                if( pDb->pBt )
                {
                        sqlite3BtreeClose(pDb->pBt);
                        pDb->pBt = NULL;
                }
        }
        sqlite3ResetInternalSchema(db, 0);
        assert( db->nDb<=2 );
        assert( db->aDb==db->aDbStatic );
        for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i))
        {
                FuncDef *pFunc, *pNext;
                for(pFunc = (FuncDef*)sqliteHashData(i); pFunc; pFunc=pNext)
                {
                        pNext = pFunc->pNext;
                        sqliteFree(pFunc);
                }
        }
        
        for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i))
        {
                CollSeq *pColl = (CollSeq *)sqliteHashData(i);
                sqliteFree(pColl);
        }
        sqlite3HashClear(&db->aCollSeq);
        
        sqlite3HashClear(&db->aFunc);
        sqlite3Error(db, SQLITE_OK, 0); /* Deallocates any cached error strings. */
        if( db->pValue )
                sqlite3ValueFree(db->pValue);
        if( db->pErr )
                sqlite3ValueFree(db->pErr);
#ifndef SQLITE_OMIT_GLOBALRECOVER
        {
                sqlite3 *pPrev;
                sqlite3OsEnterMutex();
                pPrev = pDbList;
                while( pPrev && pPrev->pNext!=db )
                        pPrev = pPrev->pNext;
                if( pPrev )
                        pPrev->pNext = db->pNext;
                else
                {
                        assert( pDbList==db );
                        pDbList = db->pNext;
                }
                sqlite3OsLeaveMutex();
        }
#endif

        db->magic = SQLITE_MAGIC_ERROR;
        sqliteFree(db);
        return SQLITE_OK;
}


/*
 * Rollback all database files.
 * */
void sqlite3RollbackAll(sqlite3 *db)
{
        int i;
        for(i=0; i<db->nDb; i++)
        {
                if( db->aDb[i].pBt )
                {
                        sqlite3BtreeRollback(db->aDb[i].pBt);
                        db->aDb[i].inTrans = 0;
                }
        }
        sqlite3ResetInternalSchema(db, 0);
}


/*
 * Return a static string that describes the kind of error specified in the
 * argument.
 * */
CONST_STRPTR sqlite3ErrStr(int rc)
{
        CONST_STRPTR z;
        switch( rc )
        {
                case SQLITE_ROW:
                case SQLITE_DONE:
                case SQLITE_OK:         z = "not an error";                                                     break;
                case SQLITE_ERROR:      z = "SQL logic error or missing database";      break;
                case SQLITE_INTERNAL:z = "internal SQLite implementation flaw"; break;
                case SQLITE_PERM:       z = "access permission denied";                         break;
                case SQLITE_ABORT:      z = "callback requested query abort";           break;
                case SQLITE_BUSY:       z = "database is locked";                                       break;
                case SQLITE_LOCKED:     z = "database table is locked";                         break;
                case SQLITE_NOMEM:      z = "out of memory";                                            break;
                case SQLITE_READONLY:z = "attempt to write a readonly database";break;
                case SQLITE_INTERRUPT:  z = "interrupted";                                              break;
                case SQLITE_IOERR:      z = "disk I/O error";                                           break;
                case SQLITE_CORRUPT:z = "database disk image is malformed";             break;
                case SQLITE_NOTFOUND:z = "table or record not found";                   break;
                case SQLITE_FULL:       z = "database is full";                                         break;
                case SQLITE_CANTOPEN:z = "unable to open database file";                break;
                case SQLITE_PROTOCOL:z = "database locking protocol failure";   break;
                case SQLITE_EMPTY:      z = "table contains no data";                           break;
                case SQLITE_SCHEMA:     z = "database schema has changed";                      break;
                case SQLITE_TOOBIG:     z = "too much data for one table row";          break;
                case SQLITE_CONSTRAINT:z = "constraint failed";                                 break;
                case SQLITE_MISMATCH:z = "datatype mismatch";                                   break;
                case SQLITE_MISUSE:     z = "library routine called out of sequence";break;
                case SQLITE_NOLFS:      z = "kernel lacks large file support";          break;
                case SQLITE_AUTH:       z = "authorization denied";                                     break;
                case SQLITE_FORMAT:     z = "auxiliary database format error";          break;
                case SQLITE_RANGE:      z = "bind or column index out of range";        break;
                case SQLITE_NOTADB:     z = "file is encrypted or is not a database";break;
                default:                        z = "unknown error";                                            break;
        }
        return z;
}


/*
 * This routine implements a busy callback that sleeps and tries again until
 * a timeout value is reached. The timeout value is an integer number of
 * milliseconds passed in as the first argument.
 * */
static int sqliteDefaultBusyCallback(
                void *ptr,               /* Database connection */
                int count                /* Number of times table has been busy */
                )
{
#if SQLITE_MIN_SLEEP_MS==1
        static const u8 delays[] =
        { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
        static const u8 totals[] =
        { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
# define NDELAY (sizeof(delays)/sizeof(delays[0]))
        int timeout = ((sqlite3 *)ptr)->busyTimeout;
        int delay, prior;
        
        assert( count>=0 );
        if( count < NDELAY )
        {
                delay = delays[count];
                prior = totals[count];
        }
        else
        {
                delay = delays[NDELAY-1];
                prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
        }
        if( prior + delay > timeout )
        {
                delay = timeout - prior;
                if( delay<=0 ) return 0;
        }
        sqlite3OsSleep(delay);
        return 1;
#else
        int timeout = ((sqlite3 *)ptr)->busyTimeout;
        if( (count+1)*1000 > timeout )
                return 0;
        sqlite3OsSleep(1000);
        return 1;
#endif
}


/*
 * This routine sets the busy callback for an Sqlite database to the given
 * callback function with the given argument.
 * */
int sqlite3_busy_handler(
                sqlite3 *db,
                int (*xBusy)(void*,int),
                void *pArg
                )
{
        if( sqlite3SafetyCheck(db) )
                return SQLITE_MISUSE;
        db->busyHandler.xFunc = xBusy;
        db->busyHandler.pArg = pArg;
        return SQLITE_OK;
}


#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
/*
 * This routine sets the progress callback for an Sqlite database to the given
 * callback function with the given argument. The progress callback will be
 * invoked every nOps opcodes.
 * */
void sqlite3_progress_handler(
                sqlite3 *db,
                int nOps,
                int (*xProgress)(void*),
                void *pArg
                )
{
        if( !sqlite3SafetyCheck(db) )
        {
                if( nOps>0 )
                {
                        db->xProgress = xProgress;
                        db->nProgressOps = nOps;
                        db->pProgressArg = pArg;
                }
                else
                {
                        db->xProgress = NULL;
                        db->nProgressOps = 0;
                        db->pProgressArg = NULL;
                }
        }
}
#endif


/*
 * This routine installs a default busy handler that waits for the specified
 * number of milliseconds before returning 0.
 * */
int sqlite3_busy_timeout(sqlite3 *db, int ms)
{
        if( ms>0 )
        {
                db->busyTimeout = ms;
                sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
        }
        else sqlite3_busy_handler(db, 0, 0);
        return SQLITE_OK;
}


/*
 * Cause any pending operation to stop at its earliest opportunity.
 * */
void sqlite3_interrupt(sqlite3 *db)
{
        if( !sqlite3SafetyCheck(db) )
                db->flags |= SQLITE_Interrupt;
}


/*
 * Windows systems should call this routine to free memory that is returned in
 * the in the errmsg parameter of sqlite3_open() when SQLite is a DLL. For some
 * reason, it does not work to call free() directly.
 *
 * Note that we need to call free() not sqliteFree() here.
 * */
void sqlite3_free(char *p){ free(p); }


/*
 * Create new user functions.
 * */
int sqlite3_create_function(
                sqlite3 *db,
                const char *zFunctionName,
                int nArg,
                int enc,
                void *pUserData,
                void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
                void (*xStep)(sqlite3_context*,int,sqlite3_value **),
                void (*xFinal)(sqlite3_context*)
                )
{
        FuncDef *p;
        int nName;
        
        if( sqlite3SafetyCheck(db) )
                return SQLITE_MISUSE;
        
        if( zFunctionName==0
                        || (xFunc && (xFinal || xStep))
                        || (!xFunc && (xFinal && !xStep))
                        || (!xFunc && (!xFinal && xStep))
                        || (nArg<-1 || nArg>127)
                        || (255<(nName = strlen(zFunctionName))) )
                return SQLITE_ERROR;
        
#ifndef SQLITE_OMIT_UTF16
        /*
         * If SQLITE_UTF16 is specified as the encoding type, transform this to one
         * of SQLITE_UTF16LE or SQLITE_UTF16BE using the SQLITE_UTF16NATIVE macro.
         * SQLITE_UTF16 is not used internally.
         *
         * If SQLITE_ANY is specified, add three versions of the function to the
         * hash table.
         * */
        if( enc==SQLITE_UTF16 )
                enc = SQLITE_UTF16NATIVE;
        else if( enc==SQLITE_ANY )
        {
                int rc;
                rc = sqlite3_create_function(db, zFunctionName, nArg, SQLITE_UTF8,
                                pUserData, xFunc, xStep, xFinal);
                if( rc!=SQLITE_OK ) return rc;
                rc = sqlite3_create_function(db, zFunctionName, nArg, SQLITE_UTF16LE,
                                pUserData, xFunc, xStep, xFinal);
                if( rc!=SQLITE_OK ) return rc;
                enc = SQLITE_UTF16BE;
        }
#else
        enc = SQLITE_UTF8;
#endif
        /*
         * Check if an existing function is being overridden or deleted. If so, and
         * there are active VMs, then return SQLITE_BUSY. If a function is being
         * overridden/deleted but there are no active VMs, allow the operation to
         * continue but invalidate all precompiled statements.
         * */
        p = sqlite3FindFunction(db, zFunctionName, nName, nArg, enc, 0);
        if( p && p->iPrefEnc==enc && p->nArg==nArg )
        {
                if( db->activeVdbeCnt )
                {
                        sqlite3Error(db, SQLITE_BUSY,
                                        "Unable to delete/modify user-function due to "
                                        "active statements");
                        return SQLITE_BUSY;
                }
                else sqlite3ExpirePreparedStatements(db);
        }
        
        p = sqlite3FindFunction(db, zFunctionName, nName, nArg, enc, 1);
        if( p==0 ) return SQLITE_NOMEM;
        p->xFunc = xFunc;
        p->xStep = xStep;
        p->xFinalize = xFinal;
        p->pUserData = pUserData;
        return SQLITE_OK;
}


#ifndef SQLITE_OMIT_UTF16
int sqlite3_create_function16(
                sqlite3 *db,
                const void *zFunctionName,
                int nArg,
                int eTextRep,
                void *pUserData,
                void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
                void (*xStep)(sqlite3_context*,int,sqlite3_value**),
                void (*xFinal)(sqlite3_context*)
                )
{
        int rc;
        char const *zFunc8;
        sqlite3_value *pTmp;

        if( sqlite3SafetyCheck(db) )
                return SQLITE_MISUSE;
        
        pTmp = sqlite3GetTransientValue(db);
        sqlite3ValueSetStr(pTmp, -1, zFunctionName, SQLITE_UTF16NATIVE,
                        SQLITE_STATIC);
        zFunc8 = sqlite3ValueText(pTmp, SQLITE_UTF8);
        
        if( !zFunc8 )
                return SQLITE_NOMEM;
        
        rc = sqlite3_create_function(db, zFunc8, nArg, eTextRep,
                        pUserData, xFunc, xStep, xFinal);
        return rc;
}
#endif


/*
 * Register a trace function. The pArg from the previously registered trace is
 * returned.
 *
 * A NULL trace function means that no tracing is executes. A non-NULL trace is
 * a pointer to a function that is invoked at the start of each sqlite3_exec().
 * */
void *sqlite3_trace(sqlite3 *db, void (*xTrace)(void*,const char*), void *pArg)
{
        void *pOld = db->pTraceArg;
        db->xTrace = xTrace;
        db->pTraceArg = pArg;
        return pOld;
}


/*** EXPERIMENTAL ***
 * 
 * Register a function to be invoked when a transaction comments. If either
 * function returns non-zero, then the commit becomes a rollback.
 * */
void *sqlite3_commit_hook(
                sqlite3 *db,              /* Attach the hook to this database */
                int (*xCallback)(void*),  /* Function to invoke on each commit */
                void *pArg                /* Argument to the function */
                )
{
        void *pOld = db->pCommitArg;
        db->xCommitCallback = xCallback;
        db->pCommitArg = pArg;
        return pOld;
}


/*
 * This routine is called to create a connection to a database BTree driver.
 * If zFilename is the name of a file, then that file is opened and used. If
 * zFilename is the magic name ":memory:" then the database is stored in memory
 * (and is thus forgotten as soon as the connection is closed.) If zFilename is
 * NULL then the database is for temporary use only and is deleted as soon as
 * the connection is closed.
 *
 * A temporary database can be either a disk file (that is automatically
 * deleted when the file is closed) or a set of red-black trees held in memory,
 * depending on the values of the TEMP_STORE compile-time macro and the
 * db->temp_store variable, according to the following chart:
 *
 *       TEMP_STORE     db->temp_store     Location of temporary database
 *       ----------     --------------     ------------------------------
 *           0               any             file
 *           1                1              file
 *           1                2              memory
 *           1                0              file
 *           2                1              file
 *           2                2              memory
 *           2                0              memory
 *           3               any             memory
 * */
int sqlite3BtreeFactory(
                const sqlite3 *db,     /* Main database when opening aux otherwise 0 */
                const char *zFilename, /* Name of the file containing the BTree db */
                int omitJournal,       /* if TRUE then do not journal this file */
                int nCache,            /* How many pages in the page cache */
                Btree **ppBtree        /* Pointer to new Btree object written here */
                )
{
        int btree_flags = 0;
        int rc;
        
        assert( ppBtree != 0);
        if( omitJournal )
                btree_flags |= BTREE_OMIT_JOURNAL;
        if( db->flags & SQLITE_NoReadlock )
                btree_flags |= BTREE_NO_READLOCK;
        if( !zFilename )
        {
#if TEMP_STORE==0
                /* Do nothing */
#endif
#ifndef SQLITE_OMIT_MEMORYDB
#if TEMP_STORE==1
                if( db->temp_store==2 ) zFilename = ":memory:";
#endif
#if TEMP_STORE==2
                if( db->temp_store!=1 ) zFilename = ":memory:";
#endif
#if TEMP_STORE==3
                zFilename = ":memory:";
#endif
#endif /* SQLITE_OMIT_MEMORYDB */
        }

        rc = sqlite3BtreeOpen(zFilename, ppBtree, btree_flags);
        if( rc==SQLITE_OK )
        {
                sqlite3BtreeSetBusyHandler(*ppBtree, (void*)&db->busyHandler);
                sqlite3BtreeSetCacheSize(*ppBtree, nCache);
        }
        return rc;
}


/*
 * Return UTF-8 encoded English language explanation of the most recent error.
 * */
const char *sqlite3_errmsg(sqlite3 *db)
{
        const char *z;
        if( sqlite3_malloc_failed )
                return sqlite3ErrStr(SQLITE_NOMEM);
        if( sqlite3SafetyCheck(db) || db->errCode==SQLITE_MISUSE )
                return sqlite3ErrStr(SQLITE_MISUSE);
        if( !( z = sqlite3_value_text(db->pErr) ))
                z = sqlite3ErrStr(db->errCode);
        return z;
}


#ifndef SQLITE_OMIT_UTF16
/*
 * Return UTF-16 encoded English language explanation of the most recent error.
 * */
const void *sqlite3_errmsg16(sqlite3 *db)
{
        /*
         * Because all the characters in the string are in the unicode range 0x00-
         * 0xFF, if we pad the big-endian string with a zero byte, we can obtain
         * the little-endian string with &big_endian[1].
         * */
        static const char outOfMemBe[] = {
                0, 'o', 0, 'u', 0, 't', 0, ' ',
                0, 'o', 0, 'f', 0, ' ',
                0, 'm', 0, 'e', 0, 'm', 0, 'o', 0, 'r', 0, 'y', 0, 0, 0
        };
        static const char misuseBe [] = {
                0, 'l', 0, 'i', 0, 'b', 0, 'r', 0, 'a', 0, 'r', 0, 'y', 0, ' ',
                0, 'r', 0, 'o', 0, 'u', 0, 't', 0, 'i', 0, 'n', 0, 'e', 0, ' ',
                0, 'c', 0, 'a', 0, 'l', 0, 'l', 0, 'e', 0, 'd', 0, ' ',
                0, 'o', 0, 'u', 0, 't', 0, ' ',
                0, 'o', 0, 'f', 0, ' ',
                0, 's', 0, 'e', 0, 'q', 0, 'u', 0, 'e', 0, 'n', 0, 'c', 0, 'e', 0, 0, 0
        };
        const void *z;
        
        if( sqlite3_malloc_failed )
                return (void *)(&outOfMemBe[SQLITE_UTF16NATIVE==SQLITE_UTF16LE?1:0]);
        if( sqlite3SafetyCheck(db) || db->errCode==SQLITE_MISUSE )
                return (void *)(&misuseBe[SQLITE_UTF16NATIVE==SQLITE_UTF16LE?1:0]);
        if( !( z = sqlite3_value_text16(db->pErr) ))
        {
                sqlite3ValueSetStr(db->pErr, -1, sqlite3ErrStr(db->errCode),
                                SQLITE_UTF8, SQLITE_STATIC);
                z = sqlite3_value_text16(db->pErr);
        }
        return z;
}
#endif /* SQLITE_OMIT_UTF16 */


/*
 * Return the most recent error code generated by an SQLite routine.
 * */
int sqlite3_errcode(sqlite3 *db)
{
        if( sqlite3_malloc_failed )
                return SQLITE_NOMEM;
        if( sqlite3SafetyCheck(db) )
                return SQLITE_MISUSE;
        return db->errCode;
}


/*
 * This routine does the work of opening a database on behalf of sqlite3_open()
 * and sqlite3_open16(). The database filename "zFilename" is UTF-8 encoded.
 * */
static int openDatabase(
                const char *zFilename, /* Database filename UTF-8 encoded */
                sqlite3 **ppDb         /* OUT: Returned database handle */
                )
{
        sqlite3 *db;
        int rc, i;

        /* Allocate the sqlite data structure */
        db = sqliteMalloc( sizeof(sqlite3) );
        if( db==0 ) goto opendb_out;
        db->priorNewRowid = 0;
        db->magic = SQLITE_MAGIC_BUSY;
        db->nDb = 2;
        db->aDb = db->aDbStatic;
        db->enc = SQLITE_UTF8;
        db->autoCommit = TRUE;
        db->flags |= SQLITE_ShortColNames;
        sqlite3HashInit(&db->aFunc, SQLITE_HASH_STRING, 0);
        sqlite3HashInit(&db->aCollSeq, SQLITE_HASH_STRING, 0);
        for(i=0; i<db->nDb; i++)
        {
                sqlite3HashInit(&db->aDb[i].tblHash, SQLITE_HASH_STRING, 0);
                sqlite3HashInit(&db->aDb[i].idxHash, SQLITE_HASH_STRING, 0);
                sqlite3HashInit(&db->aDb[i].trigHash, SQLITE_HASH_STRING, 0);
                sqlite3HashInit(&db->aDb[i].aFKey, SQLITE_HASH_STRING, 1);
        }
        
        /*
         * Add the default collation sequence BINARY. BINARY works for both UTF-8
         * and UTF-16, so add a version for each to avoid any unnecessary
         * conversions. The only error that can occur here is a malloc() failure.
         * */
        if( sqlite3_create_collation(db, "BINARY", SQLITE_UTF8, 0,binCollFunc)
                        || sqlite3_create_collation(db, "BINARY", SQLITE_UTF16,
                                0,binCollFunc)
                        || !(db->pDfltColl = sqlite3FindCollSeq(db, db->enc, "BINARY",
                                        6, 0)) )
        {
                rc = db->errCode;
                assert( rc!=SQLITE_OK );
                db->magic = SQLITE_MAGIC_CLOSED;
                goto opendb_out;
        }

        /* Also add a UTF-8 case-insensitive collation sequence. */
        sqlite3_create_collation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc);

        /* Open the backend database driver */
        rc = sqlite3BtreeFactory(db, zFilename, 0, MAX_PAGES, &db->aDb[0].pBt);
        if( rc!=SQLITE_OK )
        {
                sqlite3Error(db, rc, 0);
                db->magic = SQLITE_MAGIC_CLOSED;
                goto opendb_out;
        }

        /*
         * The default safety_level for the main database is 'full'; for the temp
         * database it is 'NONE'. This matches the pager layer defaults.
         * */
        db->aDb[0].zName = "main";
        db->aDb[0].safety_level = 3;
#ifndef SQLITE_OMIT_TEMPDB
        db->aDb[1].zName = "temp";
        db->aDb[1].safety_level = 1;
#endif

        /*
         * Register all built-in functions, but do not attempt to read the database
         * schema yet. This is delayed until the first time the database is
         * accessed.
         * */
        sqlite3RegisterBuiltinFunctions(db);
        sqlite3Error(db, SQLITE_OK, 0);
        db->magic = SQLITE_MAGIC_OPEN;

opendb_out:
        if( sqlite3_errcode(db)==SQLITE_OK && sqlite3_malloc_failed )
                sqlite3Error(db, SQLITE_NOMEM, 0);
        *ppDb = db;
#ifndef SQLITE_OMIT_GLOBALRECOVER
        if( db )
        {
                sqlite3OsEnterMutex();
                db->pNext = pDbList;
                pDbList = db;
                sqlite3OsLeaveMutex();
        }
#endif
        return sqlite3_errcode(db);
}


/*
 * Open a new database handle.
 * */
int sqlite3_open( const char *zFilename, sqlite3 **ppDb )
{
        return openDatabase(zFilename, ppDb);
}


#ifndef SQLITE_OMIT_UTF16
/*
 * Open a new database handle.
 * */
int sqlite3_open16( const void *zFilename, sqlite3 **ppDb )
{
        char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
        int rc = SQLITE_NOMEM;
        sqlite3_value *pVal;

        assert( ppDb );
        *ppDb = 0;
        pVal = sqlite3ValueNew();
        sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
        zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
        if( zFilename8 )
        {
                rc = openDatabase(zFilename8, ppDb);
                if( rc==SQLITE_OK && *ppDb )
                        sqlite3_exec(*ppDb, "PRAGMA encoding = 'UTF-16'", 0, 0, 0);
        }
        if( pVal )
                sqlite3ValueFree(pVal);
        
        return rc;
}
#endif /* SQLITE_OMIT_UTF16 */


/*
** 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{
    rc = sqlite3VdbeFinalize((Vdbe*)pStmt);
  }
  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{
    rc = sqlite3VdbeReset((Vdbe*)pStmt);
    sqlite3VdbeMakeReady((Vdbe*)pStmt, -1, 0, 0, 0, 0);
  }
  return rc;
}

/*
** Register a new collation sequence with the database handle db.
*/
int sqlite3_create_collation(
  sqlite3* db, 
  const char *zName, 
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*)
){
  CollSeq *pColl;
  int rc = SQLITE_OK;
  
  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }

  /* If SQLITE_UTF16 is specified as the encoding type, transform this
  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
  */
  if( enc==SQLITE_UTF16 ){
    enc = SQLITE_UTF16NATIVE;
  }

  if( enc!=SQLITE_UTF8 && enc!=SQLITE_UTF16LE && enc!=SQLITE_UTF16BE ){
    sqlite3Error(db, SQLITE_ERROR, 
        "Param 3 to sqlite3_create_collation() must be one of "
        "SQLITE_UTF8, SQLITE_UTF16, SQLITE_UTF16LE or SQLITE_UTF16BE"
    );
    return SQLITE_ERROR;
  }

  /* Check if this call is removing or replacing an existing collation 
  ** sequence. If so, and there are active VMs, return busy. If there
  ** are no active VMs, invalidate any pre-compiled statements.
  */
  pColl = sqlite3FindCollSeq(db, (u8)enc, zName, strlen(zName), 0);
  if( pColl && pColl->xCmp ){
    if( db->activeVdbeCnt ){
      sqlite3Error(db, SQLITE_BUSY, 
        "Unable to delete/modify collation sequence due to active statements");
      return SQLITE_BUSY;
    }
    sqlite3ExpirePreparedStatements(db);
  }

  pColl = sqlite3FindCollSeq(db, (u8)enc, zName, strlen(zName), 1);
  if( 0==pColl ){
   rc = SQLITE_NOMEM;
  }else{
    pColl->xCmp = xCompare;
    pColl->pUser = pCtx;
    pColl->enc = enc;
  }
  sqlite3Error(db, rc, 0);
  return rc;
}

#ifndef SQLITE_OMIT_UTF16
/*
** Register a new collation sequence with the database handle db.
*/
int sqlite3_create_collation16(
  sqlite3* db, 
  const char *zName, 
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*)
){
  char const *zName8;
  sqlite3_value *pTmp;
  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }
  pTmp = sqlite3GetTransientValue(db);
  sqlite3ValueSetStr(pTmp, -1, zName, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  zName8 = sqlite3ValueText(pTmp, SQLITE_UTF8);
  return sqlite3_create_collation(db, zName8, enc, pCtx, xCompare);
}
#endif /* SQLITE_OMIT_UTF16 */

/*
** Register a collation sequence factory callback with the database handle
** db. Replace any previously installed collation sequence factory.
*/
int sqlite3_collation_needed(
  sqlite3 *db, 
  void *pCollNeededArg, 
  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
){
  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }
  db->xCollNeeded = xCollNeeded;
  db->xCollNeeded16 = 0;
  db->pCollNeededArg = pCollNeededArg;
  return SQLITE_OK;
}

#ifndef SQLITE_OMIT_UTF16
/*
** Register a collation sequence factory callback with the database handle
** db. Replace any previously installed collation sequence factory.
*/
int sqlite3_collation_needed16(
  sqlite3 *db, 
  void *pCollNeededArg, 
  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
){
  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }
  db->xCollNeeded = 0;
  db->xCollNeeded16 = xCollNeeded16;
  db->pCollNeededArg = pCollNeededArg;
  return SQLITE_OK;
}
#endif /* SQLITE_OMIT_UTF16 */

#ifndef SQLITE_OMIT_GLOBALRECOVER
/*
** This function is called to recover from a malloc failure that occured
** within SQLite. 
**
** This function is *not* threadsafe. Calling this from within a threaded
** application when threads other than the caller have used SQLite is 
** dangerous and will almost certainly result in malfunctions.
*/
int sqlite3_global_recover(){
  int rc = SQLITE_OK;

  if( sqlite3_malloc_failed ){
    sqlite3 *db;
    int i;
    sqlite3_malloc_failed = 0;
    for(db=pDbList; db; db=db->pNext ){
      sqlite3ExpirePreparedStatements(db);
      for(i=0; i<db->nDb; i++){
        Btree *pBt = db->aDb[i].pBt;
        if( pBt && (rc=sqlite3BtreeReset(pBt)) ){
          goto recover_out;
        }
      } 
      db->autoCommit = 1;
    }
  }

recover_out:
  if( rc!=SQLITE_OK ){
    sqlite3_malloc_failed = 1;
  }
  return rc;
}
#endif

/*
** Test to see whether or not the database connection is in autocommit
** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
** by default.  Autocommit is disabled by a BEGIN statement and reenabled
** by the next COMMIT or ROLLBACK.
**
******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
*/
int sqlite3_get_autocommit(sqlite3 *db){
  return db->autoCommit;
}