/*
** Return a pointer corresponding to database zDb (i.e. "main", "temp")
** in connection handle pDb. If such a database cannot be found, return
** a NULL pointer and write an error message to pErrorDb.
**
** If the "temp" database is requested, it may need to be opened by this
** function. If an error occurs while doing so, return 0 and write an
** error message to pErrorDb.
*/
static Btree *findBtree(sqlite3 *pErrorDb, sqlite3 *pDb, const char *zDb) {
int i = sqlite3FindDbName(pDb, zDb);
if( i==1 ) {
Parse *pParse;
int rc = 0;
pParse = sqlite3StackAllocZero(pErrorDb, sizeof(*pParse));
if( pParse==0 ) {
sqlite3Error(pErrorDb, SQLITE_NOMEM, "out of memory");
rc = SQLITE_NOMEM;
} else {
pParse->db = pDb;
if( sqlite3OpenTempDatabase(pParse) ) {
sqlite3Error(pErrorDb, pParse->rc, "%s", pParse->zErrMsg);
rc = SQLITE_ERROR;
}
sqlite3DbFree(pErrorDb, pParse->zErrMsg);
sqlite3StackFree(pErrorDb, pParse);
}
if( rc ) {
return 0;
}
}
if( i<0 ) {
sqlite3Error(pErrorDb, SQLITE_ERROR, "unknown database %s", zDb);
return 0;
}
return pDb->aDb[i].pBt;
}
/*
** This function is used to set the schema of a virtual table. It is only
** valid to call this function from within the xCreate() or xConnect() of a
** virtual table module.
*/
int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
Parse *pParse;
int rc = SQLITE_OK;
Table *pTab;
char *zErr = 0;
sqlite3_mutex_enter(db->mutex);
if( !db->pVtabCtx || !(pTab = db->pVtabCtx->pTab) ){
sqlite3Error(db, SQLITE_MISUSE);
sqlite3_mutex_leave(db->mutex);
return SQLITE_MISUSE_BKPT;
}
assert( (pTab->tabFlags & TF_Virtual)!=0 );
pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
if( pParse==0 ){
rc = SQLITE_NOMEM;
}else{
pParse->declareVtab = 1;
pParse->db = db;
pParse->nQueryLoop = 1;
if( SQLITE_OK==sqlite3RunParser(pParse, zCreateTable, &zErr)
&& pParse->pNewTable
&& !db->mallocFailed
&& !pParse->pNewTable->pSelect
&& (pParse->pNewTable->tabFlags & TF_Virtual)==0
){
if( !pTab->aCol ){
pTab->aCol = pParse->pNewTable->aCol;
pTab->nCol = pParse->pNewTable->nCol;
pParse->pNewTable->nCol = 0;
pParse->pNewTable->aCol = 0;
}
db->pVtabCtx->pTab = 0;
}else{
sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr);
sqlite3DbFree(db, zErr);
rc = SQLITE_ERROR;
}
pParse->declareVtab = 0;
if( pParse->pVdbe ){
sqlite3VdbeFinalize(pParse->pVdbe);
}
sqlite3DeleteTable(db, pParse->pNewTable);
sqlite3ParserReset(pParse);
sqlite3StackFree(db, pParse);
}
assert( (rc&0xff)==rc );
rc = sqlite3ApiExit(db, rc);
sqlite3_mutex_leave(db->mutex);
return rc;
}
/*
** This function is used to set the schema of a virtual table. It is only
** valid to call this function from within the xCreate() or xConnect() of a
** virtual table module.
*/
int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
VtabCtx *pCtx;
Parse *pParse;
int rc = SQLITE_OK;
Table *pTab;
char *zErr = 0;
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){
return SQLITE_MISUSE_BKPT;
}
#endif
sqlite3_mutex_enter(db->mutex);
pCtx = db->pVtabCtx;
if( !pCtx || pCtx->bDeclared ){
sqlite3Error(db, SQLITE_MISUSE);
sqlite3_mutex_leave(db->mutex);
return SQLITE_MISUSE_BKPT;
}
pTab = pCtx->pTab;
assert( (pTab->tabFlags & TF_Virtual)!=0 );
pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
if( pParse==0 ){
rc = SQLITE_NOMEM_BKPT;
}else{
pParse->declareVtab = 1;
pParse->db = db;
pParse->nQueryLoop = 1;
if( SQLITE_OK==sqlite3RunParser(pParse, zCreateTable, &zErr)
&& pParse->pNewTable
&& !db->mallocFailed
&& !pParse->pNewTable->pSelect
&& (pParse->pNewTable->tabFlags & TF_Virtual)==0
){
if( !pTab->aCol ){
Table *pNew = pParse->pNewTable;
Index *pIdx;
pTab->aCol = pNew->aCol;
pTab->nCol = pNew->nCol;
pTab->tabFlags |= pNew->tabFlags & (TF_WithoutRowid|TF_NoVisibleRowid);
pNew->nCol = 0;
pNew->aCol = 0;
assert( pTab->pIndex==0 );
if( !HasRowid(pNew) && pCtx->pVTable->pMod->pModule->xUpdate!=0 ){
rc = SQLITE_ERROR;
}
pIdx = pNew->pIndex;
if( pIdx ){
assert( pIdx->pNext==0 );
pTab->pIndex = pIdx;
pNew->pIndex = 0;
pIdx->pTable = pTab;
}
}
pCtx->bDeclared = 1;
}else{
sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr);
sqlite3DbFree(db, zErr);
rc = SQLITE_ERROR;
}
pParse->declareVtab = 0;
if( pParse->pVdbe ){
sqlite3VdbeFinalize(pParse->pVdbe);
}
sqlite3DeleteTable(db, pParse->pNewTable);
sqlite3ParserReset(pParse);
sqlite3StackFree(db, pParse);
}
assert( (rc&0xff)==rc );
rc = sqlite3ApiExit(db, rc);
sqlite3_mutex_leave(db->mutex);
return rc;
}
/*
** Open a blob handle.
*/
int sqlite3_blob_open(
sqlite3* db, /* The database connection */
const char *zDb, /* The attached database containing the blob */
const char *zTable, /* The table containing the blob */
const char *zColumn, /* The column containing the blob */
sqlite_int64 iRow, /* The row containing the glob */
int flags, /* True -> read/write access, false -> read-only */
sqlite3_blob **ppBlob /* Handle for accessing the blob returned here */
){
int nAttempt = 0;
int iCol; /* Index of zColumn in row-record */
/* This VDBE program seeks a btree cursor to the identified
** db/table/row entry. The reason for using a vdbe program instead
** of writing code to use the b-tree layer directly is that the
** vdbe program will take advantage of the various transaction,
** locking and error handling infrastructure built into the vdbe.
**
** After seeking the cursor, the vdbe executes an OP_ResultRow.
** Code external to the Vdbe then "borrows" the b-tree cursor and
** uses it to implement the blob_read(), blob_write() and
** blob_bytes() functions.
**
** The sqlite3_blob_close() function finalizes the vdbe program,
** which closes the b-tree cursor and (possibly) commits the
** transaction.
*/
static const VdbeOpList openBlob[] = {
{OP_Transaction, 0, 0, 0}, /* 0: Start a transaction */
{OP_VerifyCookie, 0, 0, 0}, /* 1: Check the schema cookie */
{OP_TableLock, 0, 0, 0}, /* 2: Acquire a read or write lock */
/* One of the following two instructions is replaced by an OP_Noop. */
{OP_OpenRead, 0, 0, 0}, /* 3: Open cursor 0 for reading */
{OP_OpenWrite, 0, 0, 0}, /* 4: Open cursor 0 for read/write */
{OP_Variable, 1, 1, 1}, /* 5: Push the rowid to the stack */
{OP_NotExists, 0, 9, 1}, /* 6: Seek the cursor */
{OP_Column, 0, 0, 1}, /* 7 */
{OP_ResultRow, 1, 0, 0}, /* 8 */
{OP_Close, 0, 0, 0}, /* 9 */
{OP_Halt, 0, 0, 0}, /* 10 */
};
Vdbe *v = 0;
int rc = SQLITE_OK;
char *zErr = 0;
Table *pTab;
Parse *pParse;
*ppBlob = 0;
sqlite3_mutex_enter(db->mutex);
pParse = sqlite3StackAllocRaw(db, sizeof(*pParse));
if( pParse==0 ){
rc = SQLITE_NOMEM;
goto blob_open_out;
}
do {
memset(pParse, 0, sizeof(Parse));
pParse->db = db;
if( sqlite3SafetyOn(db) ){
sqlite3DbFree(db, zErr);
sqlite3StackFree(db, pParse);
sqlite3_mutex_leave(db->mutex);
return SQLITE_MISUSE;
}
sqlite3BtreeEnterAll(db);
pTab = sqlite3LocateTable(pParse, 0, zTable, zDb);
if( pTab && IsVirtual(pTab) ){
pTab = 0;
sqlite3ErrorMsg(pParse, "cannot open virtual table: %s", zTable);
}
#ifndef SQLITE_OMIT_VIEW
if( pTab && pTab->pSelect ){
pTab = 0;
sqlite3ErrorMsg(pParse, "cannot open view: %s", zTable);
}
#endif
if( !pTab ){
if( pParse->zErrMsg ){
sqlite3DbFree(db, zErr);
zErr = pParse->zErrMsg;
pParse->zErrMsg = 0;
}
rc = SQLITE_ERROR;
(void)sqlite3SafetyOff(db);
sqlite3BtreeLeaveAll(db);
goto blob_open_out;
}
/* Now search pTab for the exact column. */
for(iCol=0; iCol < pTab->nCol; iCol++) {
if( sqlite3StrICmp(pTab->aCol[iCol].zName, zColumn)==0 ){
break;
}
}
if( iCol==pTab->nCol ){
sqlite3DbFree(db, zErr);
zErr = sqlite3MPrintf(db, "no such column: \"%s\"", zColumn);
rc = SQLITE_ERROR;
(void)sqlite3SafetyOff(db);
sqlite3BtreeLeaveAll(db);
goto blob_open_out;
}
/* If the value is being opened for writing, check that the
** column is not indexed. It is against the rules to open an
** indexed column for writing.
*/
if( flags ){
Index *pIdx;
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
int j;
for(j=0; j<pIdx->nColumn; j++){
if( pIdx->aiColumn[j]==iCol ){
sqlite3DbFree(db, zErr);
zErr = sqlite3MPrintf(db,
"cannot open indexed column for writing");
rc = SQLITE_ERROR;
(void)sqlite3SafetyOff(db);
sqlite3BtreeLeaveAll(db);
goto blob_open_out;
}
}
}
}
v = sqlite3VdbeCreate(db);
if( v ){
int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
sqlite3VdbeAddOpList(v, sizeof(openBlob)/sizeof(VdbeOpList), openBlob);
flags = !!flags; /* flags = (flags ? 1 : 0); */
/* Configure the OP_Transaction */
sqlite3VdbeChangeP1(v, 0, iDb);
sqlite3VdbeChangeP2(v, 0, flags);
/* Configure the OP_VerifyCookie */
sqlite3VdbeChangeP1(v, 1, iDb);
sqlite3VdbeChangeP2(v, 1, pTab->pSchema->schema_cookie);
/* Make sure a mutex is held on the table to be accessed */
sqlite3VdbeUsesBtree(v, iDb);
/* Configure the OP_TableLock instruction */
sqlite3VdbeChangeP1(v, 2, iDb);
sqlite3VdbeChangeP2(v, 2, pTab->tnum);
sqlite3VdbeChangeP3(v, 2, flags);
sqlite3VdbeChangeP4(v, 2, pTab->zName, P4_TRANSIENT);
/* Remove either the OP_OpenWrite or OpenRead. Set the P2
** parameter of the other to pTab->tnum. */
sqlite3VdbeChangeToNoop(v, 4 - flags, 1);
sqlite3VdbeChangeP2(v, 3 + flags, pTab->tnum);
sqlite3VdbeChangeP3(v, 3 + flags, iDb);
/* Configure the number of columns. Configure the cursor to
** think that the table has one more column than it really
** does. An OP_Column to retrieve this imaginary column will
** always return an SQL NULL. This is useful because it means
** we can invoke OP_Column to fill in the vdbe cursors type
** and offset cache without causing any IO.
*/
sqlite3VdbeChangeP4(v, 3+flags, SQLITE_INT_TO_PTR(pTab->nCol+1),P4_INT32);
sqlite3VdbeChangeP2(v, 7, pTab->nCol);
if( !db->mallocFailed ){
sqlite3VdbeMakeReady(v, 1, 1, 1, 0);
}
}
sqlite3BtreeLeaveAll(db);
rc = sqlite3SafetyOff(db);
if( NEVER(rc!=SQLITE_OK) || db->mallocFailed ){
goto blob_open_out;
}
sqlite3_bind_int64((sqlite3_stmt *)v, 1, iRow);
rc = sqlite3_step((sqlite3_stmt *)v);
if( rc!=SQLITE_ROW ){
nAttempt++;
rc = sqlite3_finalize((sqlite3_stmt *)v);
sqlite3DbFree(db, zErr);
zErr = sqlite3MPrintf(db, sqlite3_errmsg(db));
v = 0;
}
} while( nAttempt<5 && rc==SQLITE_SCHEMA );
if( rc==SQLITE_ROW ){
/* The row-record has been opened successfully. Check that the
** column in question contains text or a blob. If it contains
** text, it is up to the caller to get the encoding right.
*/
Incrblob *pBlob;
u32 type = v->apCsr[0]->aType[iCol];
if( type<12 ){
sqlite3DbFree(db, zErr);
zErr = sqlite3MPrintf(db, "cannot open value of type %s",
type==0?"null": type==7?"real": "integer"
);
rc = SQLITE_ERROR;
goto blob_open_out;
}
pBlob = (Incrblob *)sqlite3DbMallocZero(db, sizeof(Incrblob));
if( db->mallocFailed ){
sqlite3DbFree(db, pBlob);
goto blob_open_out;
}
pBlob->flags = flags;
pBlob->pCsr = v->apCsr[0]->pCursor;
sqlite3BtreeEnterCursor(pBlob->pCsr);
sqlite3BtreeCacheOverflow(pBlob->pCsr);
sqlite3BtreeLeaveCursor(pBlob->pCsr);
pBlob->pStmt = (sqlite3_stmt *)v;
pBlob->iOffset = v->apCsr[0]->aOffset[iCol];
pBlob->nByte = sqlite3VdbeSerialTypeLen(type);
pBlob->db = db;
*ppBlob = (sqlite3_blob *)pBlob;
rc = SQLITE_OK;
}else if( rc==SQLITE_OK ){
sqlite3DbFree(db, zErr);
zErr = sqlite3MPrintf(db, "no such rowid: %lld", iRow);
rc = SQLITE_ERROR;
}
blob_open_out:
if( v && (rc!=SQLITE_OK || db->mallocFailed) ){
sqlite3VdbeFinalize(v);
}
sqlite3Error(db, rc, zErr);
sqlite3DbFree(db, zErr);
sqlite3StackFree(db, pParse);
rc = sqlite3ApiExit(db, rc);
sqlite3_mutex_leave(db->mutex);
return rc;
}
/*
** Attempt to load an SQLite extension library contained in the file
** zFile. The entry point is zProc. zProc may be 0 in which case a
** default entry point name (sqlite3_extension_init) is used. Use
** of the default name is recommended.
**
** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
**
** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
** error message text. The calling function should free this memory
** by calling sqlite3DbFree(db, ).
*/
static int sqlite3LoadExtension(
sqlite3 *db, /* Load the extension into this database connection */
const char *zFile, /* Name of the shared library containing extension */
const char *zProc, /* Entry point. Use "sqlite3_extension_init" if 0 */
char **pzErrMsg /* Put error message here if not 0 */
){
sqlite3_vfs *pVfs = db->pVfs;
void *handle;
int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
char *zErrmsg = 0;
void **aHandle;
const int nMsg = 300;
if( pzErrMsg ) *pzErrMsg = 0;
/* Ticket #1863. To avoid a creating security problems for older
** applications that relink against newer versions of SQLite, the
** ability to run load_extension is turned off by default. One
** must call sqlite3_enable_load_extension() to turn on extension
** loading. Otherwise you get the following error.
*/
if( (db->flags & SQLITE_LoadExtension)==0 ){
if( pzErrMsg ){
*pzErrMsg = sqlite3_mprintf("not authorized");
}
return SQLITE_ERROR;
}
if( zProc==0 ){
zProc = "sqlite3_extension_init";
}
handle = sqlite3OsDlOpen(pVfs, zFile);
if( handle==0 ){
if( pzErrMsg ){
zErrmsg = sqlite3StackAllocZero(db, nMsg);
if( zErrmsg ){
sqlite3_snprintf(nMsg, zErrmsg,
"unable to open shared library [%s]", zFile);
sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);
*pzErrMsg = sqlite3DbStrDup(0, zErrmsg);
sqlite3StackFree(db, zErrmsg);
}
}
return SQLITE_ERROR;
}
xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
sqlite3OsDlSym(pVfs, handle, zProc);
if( xInit==0 ){
if( pzErrMsg ){
zErrmsg = sqlite3StackAllocZero(db, nMsg);
if( zErrmsg ){
sqlite3_snprintf(nMsg, zErrmsg,
"no entry point [%s] in shared library [%s]", zProc,zFile);
sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);
*pzErrMsg = sqlite3DbStrDup(0, zErrmsg);
sqlite3StackFree(db, zErrmsg);
}
sqlite3OsDlClose(pVfs, handle);
}
return SQLITE_ERROR;
}else if( xInit(db, &zErrmsg, &sqlite3Apis) ){
if( pzErrMsg ){
*pzErrMsg = sqlite3_mprintf("error during initialization: %s", zErrmsg);
}
sqlite3_free(zErrmsg);
sqlite3OsDlClose(pVfs, handle);
return SQLITE_ERROR;
}
/* Append the new shared library handle to the db->aExtension array. */
aHandle = sqlite3DbMallocZero(db, sizeof(handle)*(db->nExtension+1));
if( aHandle==0 ){
return SQLITE_NOMEM;
}
if( db->nExtension>0 ){
memcpy(aHandle, db->aExtension, sizeof(handle)*db->nExtension);
}
sqlite3DbFree(db, db->aExtension);
db->aExtension = aHandle;
db->aExtension[db->nExtension++] = handle;
return SQLITE_OK;
}
/*
** Create and populate a new TriggerPrg object with a sub-program
** implementing trigger pTrigger with ON CONFLICT policy orconf.
*/
static TriggerPrg *codeRowTrigger(
Parse *pParse, /* Current parse context */
Trigger *pTrigger, /* Trigger to code */
Table *pTab, /* The table pTrigger is attached to */
int orconf /* ON CONFLICT policy to code trigger program with */
){
Parse *pTop = sqlite3ParseToplevel(pParse);
sqlite3 *db = pParse->db; /* Database handle */
TriggerPrg *pPrg; /* Value to return */
Expr *pWhen = 0; /* Duplicate of trigger WHEN expression */
Vdbe *v; /* Temporary VM */
NameContext sNC; /* Name context for sub-vdbe */
SubProgram *pProgram = 0; /* Sub-vdbe for trigger program */
Parse *pSubParse; /* Parse context for sub-vdbe */
int iEndTrigger = 0; /* Label to jump to if WHEN is false */
assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) );
assert( pTop->pVdbe );
/* Allocate the TriggerPrg and SubProgram objects. To ensure that they
** are freed if an error occurs, link them into the Parse.pTriggerPrg
** list of the top-level Parse object sooner rather than later. */
pPrg = sqlite3DbMallocZero(db, sizeof(TriggerPrg));
if( !pPrg ) return 0;
pPrg->pNext = pTop->pTriggerPrg;
pTop->pTriggerPrg = pPrg;
pPrg->pProgram = pProgram = sqlite3DbMallocZero(db, sizeof(SubProgram));
if( !pProgram ) return 0;
sqlite3VdbeLinkSubProgram(pTop->pVdbe, pProgram);
pPrg->pTrigger = pTrigger;
pPrg->orconf = orconf;
pPrg->aColmask[0] = 0xffffffff;
pPrg->aColmask[1] = 0xffffffff;
/* Allocate and populate a new Parse context to use for coding the
** trigger sub-program. */
pSubParse = sqlite3StackAllocZero(db, sizeof(Parse));
if( !pSubParse ) return 0;
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pSubParse;
pSubParse->db = db;
pSubParse->pTriggerTab = pTab;
pSubParse->pToplevel = pTop;
pSubParse->zAuthContext = pTrigger->zName;
pSubParse->eTriggerOp = pTrigger->op;
pSubParse->nQueryLoop = pParse->nQueryLoop;
v = sqlite3GetVdbe(pSubParse);
if( v ){
VdbeComment((v, "Start: %s.%s (%s %s%s%s ON %s)",
pTrigger->zName, onErrorText(orconf),
(pTrigger->tr_tm==TRIGGER_BEFORE ? "BEFORE" : "AFTER"),
(pTrigger->op==TK_UPDATE ? "UPDATE" : ""),
(pTrigger->op==TK_INSERT ? "INSERT" : ""),
(pTrigger->op==TK_DELETE ? "DELETE" : ""),
pTab->zName
));
#ifndef SQLITE_OMIT_TRACE
sqlite3VdbeChangeP4(v, -1,
sqlite3MPrintf(db, "-- TRIGGER %s", pTrigger->zName), P4_DYNAMIC
);
#endif
/* If one was specified, code the WHEN clause. If it evaluates to false
** (or NULL) the sub-vdbe is immediately halted by jumping to the
** OP_Halt inserted at the end of the program. */
if( pTrigger->pWhen ){
pWhen = sqlite3ExprDup(db, pTrigger->pWhen, 0);
if( SQLITE_OK==sqlite3ResolveExprNames(&sNC, pWhen)
&& db->mallocFailed==0
){
iEndTrigger = sqlite3VdbeMakeLabel(v);
sqlite3ExprIfFalse(pSubParse, pWhen, iEndTrigger, SQLITE_JUMPIFNULL);
}
sqlite3ExprDelete(db, pWhen);
}
/* Code the trigger program into the sub-vdbe. */
codeTriggerProgram(pSubParse, pTrigger->step_list, orconf);
/* Insert an OP_Halt at the end of the sub-program. */
if( iEndTrigger ){
sqlite3VdbeResolveLabel(v, iEndTrigger);
}
sqlite3VdbeAddOp0(v, OP_Halt);
VdbeComment((v, "End: %s.%s", pTrigger->zName, onErrorText(orconf)));
transferParseError(pParse, pSubParse);
if( db->mallocFailed==0 ){
pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pTop->nMaxArg);
}
pProgram->nMem = pSubParse->nMem;
pProgram->nCsr = pSubParse->nTab;
pProgram->nOnce = pSubParse->nOnce;
pProgram->token = (void *)pTrigger;
pPrg->aColmask[0] = pSubParse->oldmask;
pPrg->aColmask[1] = pSubParse->newmask;
sqlite3VdbeDelete(v);
}
assert( !pSubParse->pAinc && !pSubParse->pZombieTab );
assert( !pSubParse->pTriggerPrg && !pSubParse->nMaxArg );
sqlite3StackFree(db, pSubParse);
return pPrg;
}
/*
** Set the i-th bit. Return 0 on success and an error code if
** anything goes wrong.
**
** This routine might cause sub-bitmaps to be allocated. Failing
** to get the memory needed to hold the sub-bitmap is the only
** that can go wrong with an insert, assuming p and i are valid.
**
** The calling function must ensure that p is a valid Bitvec object
** and that the value for "i" is within range of the Bitvec object.
** Otherwise the behavior is undefined.
*/
int sqlite3BitvecSet(Bitvec *p, u32 i){
u32 h;
if( p==0 ) return SQLITE_OK;
assert( i>0 );
assert( i<=p->iSize );
i--;
while((p->iSize > BITVEC_NBIT) && p->iDivisor) {
u32 bin = i/p->iDivisor;
i = i%p->iDivisor;
if( p->u.apSub[bin]==0 ){
p->u.apSub[bin] = sqlite3BitvecCreate( p->iDivisor );
if( p->u.apSub[bin]==0 ) return SQLITE_NOMEM;
}
p = p->u.apSub[bin];
}
if( p->iSize<=BITVEC_NBIT ){
p->u.aBitmap[i/BITVEC_SZELEM] |= 1 << (i&(BITVEC_SZELEM-1));
return SQLITE_OK;
}
h = BITVEC_HASH(i++);
/* if there wasn't a hash collision, and this doesn't */
/* completely fill the hash, then just add it without */
/* worring about sub-dividing and re-hashing. */
if( !p->u.aHash[h] ){
if (p->nSet<(BITVEC_NINT-1)) {
goto bitvec_set_end;
} else {
goto bitvec_set_rehash;
}
}
/* there was a collision, check to see if it's already */
/* in hash, if not, try to find a spot for it */
do {
if( p->u.aHash[h]==i ) return SQLITE_OK;
h++;
if( h>=BITVEC_NINT ) h = 0;
} while( p->u.aHash[h] );
/* we didn't find it in the hash. h points to the first */
/* available free spot. check to see if this is going to */
/* make our hash too "full". */
bitvec_set_rehash:
if( p->nSet>=BITVEC_MXHASH ){
unsigned int j;
int rc;
u32 *aiValues = sqlite3StackAllocRaw(0, sizeof(p->u.aHash));
if( aiValues==0 ){
return SQLITE_NOMEM;
}else{
memcpy(aiValues, p->u.aHash, sizeof(p->u.aHash));
memset(p->u.apSub, 0, sizeof(p->u.apSub));
p->iDivisor = (p->iSize + BITVEC_NPTR - 1)/BITVEC_NPTR;
rc = sqlite3BitvecSet(p, i);
for(j=0; j<BITVEC_NINT; j++){
if( aiValues[j] ) rc |= sqlite3BitvecSet(p, aiValues[j]);
}
sqlite3StackFree(0, aiValues);
return rc;
}
}
bitvec_set_end:
p->nSet++;
p->u.aHash[h] = i;
return SQLITE_OK;
}
/*
** Open a blob handle.
*/
int sqlite3_blob_open(
sqlite3* db, /* The database connection */
const char *zDb, /* The attached database containing the blob */
const char *zTable, /* The table containing the blob */
const char *zColumn, /* The column containing the blob */
sqlite_int64 iRow, /* The row containing the glob */
int flags, /* True -> read/write access, false -> read-only */
sqlite3_blob **ppBlob /* Handle for accessing the blob returned here */
){
int nAttempt = 0;
int iCol; /* Index of zColumn in row-record */
/* This VDBE program seeks a btree cursor to the identified
** db/table/row entry. The reason for using a vdbe program instead
** of writing code to use the b-tree layer directly is that the
** vdbe program will take advantage of the various transaction,
** locking and error handling infrastructure built into the vdbe.
**
** After seeking the cursor, the vdbe executes an OP_ResultRow.
** Code external to the Vdbe then "borrows" the b-tree cursor and
** uses it to implement the blob_read(), blob_write() and
** blob_bytes() functions.
**
** The sqlite3_blob_close() function finalizes the vdbe program,
** which closes the b-tree cursor and (possibly) commits the
** transaction.
*/
static const VdbeOpList openBlob[] = {
{OP_Transaction, 0, 0, 0}, /* 0: Start a transaction */
{OP_VerifyCookie, 0, 0, 0}, /* 1: Check the schema cookie */
{OP_TableLock, 0, 0, 0}, /* 2: Acquire a read or write lock */
/* One of the following two instructions is replaced by an OP_Noop. */
{OP_OpenRead, 0, 0, 0}, /* 3: Open cursor 0 for reading */
{OP_OpenWrite, 0, 0, 0}, /* 4: Open cursor 0 for read/write */
{OP_Variable, 1, 1, 1}, /* 5: Push the rowid to the stack */
{OP_NotExists, 0, 10, 1}, /* 6: Seek the cursor */
{OP_Column, 0, 0, 1}, /* 7 */
{OP_ResultRow, 1, 0, 0}, /* 8 */
{OP_Goto, 0, 5, 0}, /* 9 */
{OP_Close, 0, 0, 0}, /* 10 */
{OP_Halt, 0, 0, 0}, /* 11 */
};
int rc = SQLITE_OK;
char *zErr = 0;
Table *pTab;
Parse *pParse = 0;
Incrblob *pBlob = 0;
flags = !!flags; /* flags = (flags ? 1 : 0); */
*ppBlob = 0;
sqlite3_mutex_enter(db->mutex);
pBlob = (Incrblob *)sqlite3DbMallocZero(db, sizeof(Incrblob));
if( !pBlob ) goto blob_open_out;
pParse = sqlite3StackAllocRaw(db, sizeof(*pParse));
if( !pParse ) goto blob_open_out;
do {
memset(pParse, 0, sizeof(Parse));
pParse->db = db;
sqlite3DbFree(db, zErr);
zErr = 0;
sqlite3BtreeEnterAll(db);
pTab = sqlite3LocateTable(pParse, 0, zTable, zDb);
if( pTab && IsVirtual(pTab) ){
pTab = 0;
sqlite3ErrorMsg(pParse, "cannot open virtual table: %s", zTable);
}
#ifndef SQLITE_OMIT_VIEW
if( pTab && pTab->pSelect ){
pTab = 0;
sqlite3ErrorMsg(pParse, "cannot open view: %s", zTable);
}
#endif
if( !pTab ){
if( pParse->zErrMsg ){
sqlite3DbFree(db, zErr);
zErr = pParse->zErrMsg;
pParse->zErrMsg = 0;
}
rc = SQLITE_ERROR;
sqlite3BtreeLeaveAll(db);
goto blob_open_out;
}
/* Now search pTab for the exact column. */
for(iCol=0; iCol<pTab->nCol; iCol++) {
if( sqlite3StrICmp(pTab->aCol[iCol].zName, zColumn)==0 ){
break;
}
}
if( iCol==pTab->nCol ){
sqlite3DbFree(db, zErr);
zErr = sqlite3MPrintf(db, "no such column: \"%s\"", zColumn);
rc = SQLITE_ERROR;
sqlite3BtreeLeaveAll(db);
goto blob_open_out;
}
/* If the value is being opened for writing, check that the
** column is not indexed, and that it is not part of a foreign key.
** It is against the rules to open a column to which either of these
** descriptions applies for writing. */
if( flags ){
const char *zFault = 0;
Index *pIdx;
#ifndef SQLITE_OMIT_FOREIGN_KEY
if( db->flags&SQLITE_ForeignKeys ){
/* Check that the column is not part of an FK child key definition. It
** is not necessary to check if it is part of a parent key, as parent
** key columns must be indexed. The check below will pick up this
** case. */
FKey *pFKey;
for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){
int j;
for(j=0; j<pFKey->nCol; j++){
if( pFKey->aCol[j].iFrom==iCol ){
zFault = "foreign key";
}
}
}
}
#endif
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
int j;
for(j=0; j<pIdx->nColumn; j++){
if( pIdx->aiColumn[j]==iCol ){
zFault = "indexed";
}
}
}
if( zFault ){
sqlite3DbFree(db, zErr);
zErr = sqlite3MPrintf(db, "cannot open %s column for writing", zFault);
rc = SQLITE_ERROR;
sqlite3BtreeLeaveAll(db);
goto blob_open_out;
}
}
pBlob->pStmt = (sqlite3_stmt *)sqlite3VdbeCreate(db);
assert( pBlob->pStmt || db->mallocFailed );
if( pBlob->pStmt ){
Vdbe *v = (Vdbe *)pBlob->pStmt;
int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
sqlite3VdbeAddOpList(v, sizeof(openBlob)/sizeof(VdbeOpList), openBlob);
/* Configure the OP_Transaction */
sqlite3VdbeChangeP1(v, 0, iDb);
sqlite3VdbeChangeP2(v, 0, flags);
/* Configure the OP_VerifyCookie */
sqlite3VdbeChangeP1(v, 1, iDb);
sqlite3VdbeChangeP2(v, 1, pTab->pSchema->schema_cookie);
sqlite3VdbeChangeP3(v, 1, pTab->pSchema->iGeneration);
/* Make sure a mutex is held on the table to be accessed */
sqlite3VdbeUsesBtree(v, iDb);
/* Configure the OP_TableLock instruction */
#ifdef SQLITE_OMIT_SHARED_CACHE
sqlite3VdbeChangeToNoop(v, 2);
#else
sqlite3VdbeChangeP1(v, 2, iDb);
sqlite3VdbeChangeP2(v, 2, pTab->tnum);
sqlite3VdbeChangeP3(v, 2, flags);
sqlite3VdbeChangeP4(v, 2, pTab->zName, P4_TRANSIENT);
#endif
/* Remove either the OP_OpenWrite or OpenRead. Set the P2
** parameter of the other to pTab->tnum. */
sqlite3VdbeChangeToNoop(v, 4 - flags);
sqlite3VdbeChangeP2(v, 3 + flags, pTab->tnum);
sqlite3VdbeChangeP3(v, 3 + flags, iDb);
/* Configure the number of columns. Configure the cursor to
** think that the table has one more column than it really
** does. An OP_Column to retrieve this imaginary column will
** always return an SQL NULL. This is useful because it means
** we can invoke OP_Column to fill in the vdbe cursors type
** and offset cache without causing any IO.
*/
sqlite3VdbeChangeP4(v, 3+flags, SQLITE_INT_TO_PTR(pTab->nCol+1),P4_INT32);
sqlite3VdbeChangeP2(v, 7, pTab->nCol);
if( !db->mallocFailed ){
pParse->nVar = 1;
pParse->nMem = 1;
pParse->nTab = 1;
sqlite3VdbeMakeReady(v, pParse);
}
}
pBlob->flags = flags;
pBlob->iCol = iCol;
pBlob->db = db;
sqlite3BtreeLeaveAll(db);
if( db->mallocFailed ){
goto blob_open_out;
}
sqlite3_bind_int64(pBlob->pStmt, 1, iRow);
rc = blobSeekToRow(pBlob, iRow, &zErr);
} while( (++nAttempt)<5 && rc==SQLITE_SCHEMA );
blob_open_out:
if( rc==SQLITE_OK && db->mallocFailed==0 ){
*ppBlob = (sqlite3_blob *)pBlob;
}else{
if( pBlob && pBlob->pStmt ) sqlite3VdbeFinalize((Vdbe *)pBlob->pStmt);
sqlite3DbFree(db, pBlob);
}
sqlite3Error(db, rc, (zErr ? "%s" : 0), zErr);
sqlite3DbFree(db, zErr);
sqlite3StackFree(db, pParse);
rc = sqlite3ApiExit(db, rc);
sqlite3_mutex_leave(db->mutex);
return rc;
}
/*
** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
*/
static int sqlite3Prepare(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
int saveSqlFlag, /* True to copy SQL text into the sqlite3_stmt */
Vdbe *pReprepare, /* VM being reprepared */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char **pzTail /* OUT: End of parsed string */
){
Parse *pParse; /* Parsing context */
char *zErrMsg = 0; /* Error message */
int rc = SQLITE_OK; /* Result code */
int i; /* Loop counter */
/* Allocate the parsing context */
pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
if( pParse==0 ){
rc = SQLITE_NOMEM;
goto end_prepare;
}
pParse->pReprepare = pReprepare;
if( sqlite3SafetyOn(db) ){
rc = SQLITE_MISUSE;
goto end_prepare;
}
assert( ppStmt && *ppStmt==0 );
assert( !db->mallocFailed );
assert( sqlite3_mutex_held(db->mutex) );
/* Check to verify that it is possible to get a read lock on all
** database schemas. The inability to get a read lock indicates that
** some other database connection is holding a write-lock, which in
** turn means that the other connection has made uncommitted changes
** to the schema.
**
** Were we to proceed and prepare the statement against the uncommitted
** schema changes and if those schema changes are subsequently rolled
** back and different changes are made in their place, then when this
** prepared statement goes to run the schema cookie would fail to detect
** the schema change. Disaster would follow.
**
** This thread is currently holding mutexes on all Btrees (because
** of the sqlite3BtreeEnterAll() in sqlite3LockAndPrepare()) so it
** is not possible for another thread to start a new schema change
** while this routine is running. Hence, we do not need to hold
** locks on the schema, we just need to make sure nobody else is
** holding them.
**
** Note that setting READ_UNCOMMITTED overrides most lock detection,
** but it does *not* override schema lock detection, so this all still
** works even if READ_UNCOMMITTED is set.
*/
for(i=0; i<db->nDb; i++) {
Btree *pBt = db->aDb[i].pBt;
if( pBt ){
assert( sqlite3BtreeHoldsMutex(pBt) );
rc = sqlite3BtreeSchemaLocked(pBt);
if( rc ){
const char *zDb = db->aDb[i].zName;
sqlite3Error(db, rc, "database schema is locked: %s", zDb);
(void)sqlite3SafetyOff(db);
testcase( db->flags & SQLITE_ReadUncommitted );
goto end_prepare;
}
}
}
sqlite3VtabUnlockList(db);
pParse->db = db;
if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){
char *zSqlCopy;
int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
testcase( nBytes==mxLen );
testcase( nBytes==mxLen+1 );
if( nBytes>mxLen ){
sqlite3Error(db, SQLITE_TOOBIG, "statement too long");
(void)sqlite3SafetyOff(db);
rc = sqlite3ApiExit(db, SQLITE_TOOBIG);
goto end_prepare;
}
zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
if( zSqlCopy ){
sqlite3RunParser(pParse, zSqlCopy, &zErrMsg);
sqlite3DbFree(db, zSqlCopy);
pParse->zTail = &zSql[pParse->zTail-zSqlCopy];
}else{
pParse->zTail = &zSql[nBytes];
}
}else{
sqlite3RunParser(pParse, zSql, &zErrMsg);
}
if( db->mallocFailed ){
pParse->rc = SQLITE_NOMEM;
}
if( pParse->rc==SQLITE_DONE ) pParse->rc = SQLITE_OK;
if( pParse->checkSchema ){
schemaIsValid(pParse);
}
if( pParse->rc==SQLITE_SCHEMA ){
sqlite3ResetInternalSchema(db, 0);
}
if( db->mallocFailed ){
pParse->rc = SQLITE_NOMEM;
}
if( pzTail ){
*pzTail = pParse->zTail;
}
rc = pParse->rc;
#ifndef SQLITE_OMIT_EXPLAIN
if( rc==SQLITE_OK && pParse->pVdbe && pParse->explain ){
static const char * const azColName[] = {
"addr", "opcode", "p1", "p2", "p3", "p4", "p5", "comment",
"order", "from", "detail"
};
int iFirst, mx;
if( pParse->explain==2 ){
sqlite3VdbeSetNumCols(pParse->pVdbe, 3);
iFirst = 8;
mx = 11;
}else{
sqlite3VdbeSetNumCols(pParse->pVdbe, 8);
iFirst = 0;
mx = 8;
}
for(i=iFirst; i<mx; i++){
sqlite3VdbeSetColName(pParse->pVdbe, i-iFirst, COLNAME_NAME,
azColName[i], SQLITE_STATIC);
}
}
#endif
if( sqlite3SafetyOff(db) ){
rc = SQLITE_MISUSE;
}
assert( db->init.busy==0 || saveSqlFlag==0 );
if( db->init.busy==0 ){
Vdbe *pVdbe = pParse->pVdbe;
sqlite3VdbeSetSql(pVdbe, zSql, (int)(pParse->zTail-zSql), saveSqlFlag);
}
if( pParse->pVdbe && (rc!=SQLITE_OK || db->mallocFailed) ){
sqlite3VdbeFinalize(pParse->pVdbe);
assert(!(*ppStmt));
}else{
*ppStmt = (sqlite3_stmt*)pParse->pVdbe;
}
if( zErrMsg ){
sqlite3Error(db, rc, "%s", zErrMsg);
sqlite3DbFree(db, zErrMsg);
}else{
sqlite3Error(db, rc, 0);
}
/* Delete any TriggerPrg structures allocated while parsing this statement. */
while( pParse->pTriggerPrg ){
TriggerPrg *pT = pParse->pTriggerPrg;
pParse->pTriggerPrg = pT->pNext;
sqlite3VdbeProgramDelete(db, pT->pProgram, 0);
sqlite3DbFree(db, pT);
}
end_prepare:
sqlite3StackFree(db, pParse);
rc = sqlite3ApiExit(db, rc);
assert( (rc&db->errMask)==rc );
return rc;
}