/*
** Release an array of N Mem elements
*/
static void releaseMemArray(Mem *p, int N){
if( p ){
while( N-->0 ){
sqlite3VdbeMemRelease(p++);
}
}
}
/*
** Convert pMem to type integer. Invalidate any prior representations.
*/
int sqlite3VdbeMemIntegerify(Mem *pMem){
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
pMem->u.i = sqlite3VdbeIntValue(pMem);
sqlite3VdbeMemRelease(pMem);
pMem->flags = MEM_Int;
return SQLITE_OK;
}
/*
** Convert pMem so that it is of type MEM_Real.
** Invalidate any prior representations.
*/
int sqlite3VdbeMemRealify(Mem *pMem){
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
pMem->r = sqlite3VdbeRealValue(pMem);
sqlite3VdbeMemRelease(pMem);
pMem->flags = MEM_Real;
return SQLITE_OK;
}
/*
** 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.
**
** A successful evaluation of this routine acquires the mutex on p.
** the mutex is released if any kind of error occurs.
**
** 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( vdbeSafetyNotNull(p) ){
return SQLITE_MISUSE_BKPT;
}
sqlite3_mutex_enter(p->db->mutex);
if( p->magic!=VDBE_MAGIC_RUN || p->pc>=0 ){
sqlite3Error(p->db, SQLITE_MISUSE, 0);
sqlite3_mutex_leave(p->db->mutex);
sqlite3_log(SQLITE_MISUSE,
"bind on a busy prepared statement: [%s]", p->zSql);
return SQLITE_MISUSE_BKPT;
}
if( i<1 || i>p->nVar ){
sqlite3Error(p->db, SQLITE_RANGE, 0);
sqlite3_mutex_leave(p->db->mutex);
return SQLITE_RANGE;
}
i--;
pVar = &p->aVar[i];
sqlite3VdbeMemRelease(pVar);
pVar->flags = MEM_Null;
sqlite3Error(p->db, SQLITE_OK, 0);
/* If the bit corresponding to this variable in Vdbe.expmask is set, then
** binding a new value to this variable invalidates the current query plan.
*/
if( p->isPrepareV2 &&
((i<32 && p->expmask & ((u32)1 << i)) || p->expmask==0xffffffff)
){
p->expired = 1;
}
return SQLITE_OK;
}
static void minMaxFinalize(sqlite3_context *context){
sqlite3_value *pRes;
pRes = (sqlite3_value *)sqlite3_aggregate_context(context, sizeof(Mem));
if( pRes->flags ){
sqlite3_result_value(context, pRes);
}
sqlite3VdbeMemRelease(pRes);
}
/*
** Move data out of a btree key or data field and into a Mem structure.
** The data or key is taken from the entry that pCur is currently pointing
** to. offset and amt determine what portion of the data or key to retrieve.
** key is true to get the key or false to get data. The result is written
** into the pMem element.
**
** The pMem structure is assumed to be uninitialized. Any prior content
** is overwritten without being freed.
**
** If this routine fails for any reason (malloc returns NULL or unable
** to read from the disk) then the pMem is left in an inconsistent state.
*/
int sqlite3VdbeMemFromBtree(
BtCursor *pCur, /* Cursor pointing at record to retrieve. */
int offset, /* Offset from the start of data to return bytes from. */
int amt, /* Number of bytes to return. */
int key, /* If true, retrieve from the btree key, not data. */
Mem *pMem /* OUT: Return data in this Mem structure. */
){
char *zData; /* Data from the btree layer */
int available = 0; /* Number of bytes available on the local btree page */
int rc = SQLITE_OK; /* Return code */
assert( sqlite3BtreeCursorIsValid(pCur) );
/* Note: the calls to BtreeKeyFetch() and DataFetch() below assert()
** that both the BtShared and database handle mutexes are held. */
assert( (pMem->flags & MEM_RowSet)==0 );
if( key ){
zData = (char *)sqlite3BtreeKeyFetch(pCur, &available);
}else{
zData = (char *)sqlite3BtreeDataFetch(pCur, &available);
}
assert( zData!=0 );
if( offset+amt<=available && (pMem->flags&MEM_Dyn)==0 ){
sqlite3VdbeMemRelease(pMem);
pMem->z = &zData[offset];
pMem->flags = MEM_Blob|MEM_Ephem;
}else if( SQLITE_OK==(rc = sqlite3VdbeMemGrow(pMem, amt+2, 0)) ){
pMem->flags = MEM_Blob|MEM_Dyn|MEM_Term;
pMem->enc = 0;
pMem->type = SQLITE_BLOB;
if( key ){
rc = sqlite3BtreeKey(pCur, offset, amt, pMem->z);
}else{
rc = sqlite3BtreeData(pCur, offset, amt, pMem->z);
}
pMem->z[amt] = 0;
pMem->z[amt+1] = 0;
if( rc!=SQLITE_OK ){
sqlite3VdbeMemRelease(pMem);
}
}
pMem->n = amt;
return rc;
}
/*
** Move data out of a btree key or data field and into a Mem structure.
** The data or key is taken from the entry that pCur is currently pointing
** to. offset and amt determine what portion of the data or key to retrieve.
** key is true to get the key or false to get data. The result is written
** into the pMem element.
**
** The pMem structure is assumed to be uninitialized. Any prior content
** is overwritten without being freed.
**
** If this routine fails for any reason (malloc returns NULL or unable
** to read from the disk) then the pMem is left in an inconsistent state.
*/
int sqlite3VdbeMemFromBtree(
BtCursor *pCur, /* Cursor pointing at record to retrieve. */
int offset, /* Offset from the start of data to return bytes from. */
int amt, /* Number of bytes to return. */
int key, /* If true, retrieve from the btree key, not data. */
Mem *pMem /* OUT: Return data in this Mem structure. */
){
char *zData; /* Data from the btree layer */
int available = 0; /* Number of bytes available on the local btree page */
sqlite3 *db; /* Database connection */
int rc = SQLITE_OK;
db = sqlite3BtreeCursorDb(pCur);
assert( sqlite3_mutex_held(db->mutex) );
assert( (pMem->flags & MEM_RowSet)==0 );
if( key ){
zData = (char *)sqlite3BtreeKeyFetch(pCur, &available);
}else{
zData = (char *)sqlite3BtreeDataFetch(pCur, &available);
}
assert( zData!=0 );
if( offset+amt<=available && ((pMem->flags&MEM_Dyn)==0 || pMem->xDel) ){
sqlite3VdbeMemRelease(pMem);
pMem->z = &zData[offset];
pMem->flags = MEM_Blob|MEM_Ephem;
}else if( SQLITE_OK==(rc = sqlite3VdbeMemGrow(pMem, amt+2, 0)) ){
pMem->flags = MEM_Blob|MEM_Dyn|MEM_Term;
pMem->enc = 0;
pMem->type = SQLITE_BLOB;
if( key ){
rc = sqlite3BtreeKey(pCur, offset, amt, pMem->z);
}else{
rc = sqlite3BtreeData(pCur, offset, amt, pMem->z);
}
pMem->z[amt] = 0;
pMem->z[amt+1] = 0;
if( rc!=SQLITE_OK ){
sqlite3VdbeMemRelease(pMem);
}
}
pMem->n = amt;
return rc;
}
/*
** Remove any elements that remain on the sorter for the VDBE given.
*/
void sqlite3VdbeSorterReset(Vdbe *p){
while( p->pSort ){
Sorter *pSorter = p->pSort;
p->pSort = pSorter->pNext;
sqliteFree(pSorter->zKey);
sqlite3VdbeMemRelease(&pSorter->data);
sqliteFree(pSorter);
}
}
/*
** Delete any previous value and set the value to be a BLOB of length
** n containing all zeros.
*/
void sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){
sqlite3VdbeMemRelease(pMem);
pMem->flags = MEM_Blob|MEM_Zero;
pMem->type = SQLITE_BLOB;
pMem->n = 0;
if( n<0 ) n = 0;
pMem->u.nZero = n;
pMem->enc = SQLITE_UTF8;
}
/*
** Delete any previous value and set the value stored in *pMem to val,
** manifest type REAL.
*/
void sqlite3VdbeMemSetDouble(Mem *pMem, double val){
if( sqlite3IsNaN(val) ){
sqlite3VdbeMemSetNull(pMem);
}else{
sqlite3VdbeMemRelease(pMem);
pMem->r = val;
pMem->flags = MEM_Real;
pMem->type = SQLITE_FLOAT;
}
}
/*
** If the memory cell contains a string value that must be freed by
** invoking an external callback, free it now. Calling this function
** does not free any Mem.zMalloc buffer.
*/
void sqlite3VdbeMemReleaseExternal(Mem *p){
assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
if( p->flags&MEM_Agg ){
sqlite3VdbeMemFinalize(p, p->u.pDef);
assert( (p->flags & MEM_Agg)==0 );
sqlite3VdbeMemRelease(p);
}else if( p->flags&MEM_Dyn && p->xDel ){
p->xDel((void *)p->z);
p->xDel = 0;
}
}
/*
** Transfer the contents of pFrom to pTo. Any existing value in pTo is
** freed. If pFrom contains ephemeral data, a copy is made.
**
** pFrom contains an SQL NULL when this routine returns.
*/
void sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom){
assert( pFrom->db==0 || sqlite3_mutex_held(pFrom->db->mutex) );
assert( pTo->db==0 || sqlite3_mutex_held(pTo->db->mutex) );
assert( pFrom->db==0 || pTo->db==0 || pFrom->db==pTo->db );
sqlite3VdbeMemRelease(pTo);
memcpy(pTo, pFrom, sizeof(Mem));
pFrom->flags = MEM_Null;
pFrom->xDel = 0;
pFrom->zMalloc = 0;
}
/*
** Make a full copy of pFrom into pTo. Prior contents of pTo are
** freed before the copy is made.
*/
int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
int rc;
if( pTo->flags & MEM_Dyn ){
sqlite3VdbeMemRelease(pTo);
}
sqlite3VdbeMemShallowCopy(pTo, pFrom, MEM_Ephem);
if( pTo->flags & MEM_Ephem ){
rc = sqlite3VdbeMemMakeWriteable(pTo);
}else{
rc = SQLITE_OK;
}
return rc;
}
/*
** Convert a UTF-16 string in the native encoding into a UTF-8 string.
** Memory to hold the UTF-8 string is obtained from sqlite3_malloc and must
** be freed by the calling function.
**
** NULL is returned if there is an allocation error.
*/
char *sqlite3Utf16to8(sqlite3 *db, const void *z, int nByte){
Mem m;
memset(&m, 0, sizeof(m));
m.db = db;
sqlite3VdbeMemSetStr(&m, z, nByte, SQLITE_UTF16NATIVE, SQLITE_STATIC);
sqlite3VdbeChangeEncoding(&m, SQLITE_UTF8);
if( db->mallocFailed ){
sqlite3VdbeMemRelease(&m);
m.z = 0;
}
assert( (m.flags & MEM_Term)!=0 || db->mallocFailed );
assert( (m.flags & MEM_Str)!=0 || db->mallocFailed );
return (m.flags & MEM_Dyn)!=0 ? m.z : sqlite3DbStrDup(db, m.z);
}
/*
** 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;
}
/*
** Free all resources allociated with AggElem pElem, an element of
** aggregate pAgg.
*/
void freeAggElem(AggElem *pElem, Agg *pAgg){
int i;
for(i=0; i<pAgg->nMem; i++){
Mem *pMem = &pElem->aMem[i];
if( pAgg->apFunc && pAgg->apFunc[i] && (pMem->flags & MEM_AggCtx)!=0 ){
sqlite3_context ctx;
ctx.pFunc = pAgg->apFunc[i];
ctx.s.flags = MEM_Null;
ctx.pAgg = pMem->z;
ctx.cnt = (int) pMem->i;
ctx.isStep = 0;
ctx.isError = 0;
(*pAgg->apFunc[i]->xFinalize)(&ctx);
pMem->z = ctx.pAgg;
if( pMem->z!=0 && pMem->z!=pMem->zShort ){
sqliteFree(pMem->z);
}
sqlite3VdbeMemRelease(&ctx.s);
}else{
sqlite3VdbeMemRelease(pMem);
}
}
sqliteFree(pElem);
}
/*
** Convert a UTF-16 string in the native encoding into a UTF-8 string.
** Memory to hold the UTF-8 string is obtained from sqlite3_malloc and must
** be freed by the calling function.
**
** NULL is returned if there is an allocation error.
*/
char *sqlite3Utf16to8(sqlite3 *db, const void *z, int nByte, u8 enc){
Mem m;
memset(&m, 0, sizeof(m));
m.db = db;
sqlite3VdbeMemSetStr(&m, z, nByte, enc, SQLITE_STATIC);
sqlite3VdbeChangeEncoding(&m, SQLITE_UTF8);
if( db->mallocFailed ){
sqlite3VdbeMemRelease(&m);
m.z = 0;
}
assert( (m.flags & MEM_Term)!=0 || db->mallocFailed );
assert( (m.flags & MEM_Str)!=0 || db->mallocFailed );
assert( m.z || db->mallocFailed );
return m.z;
}
/*
** Delete any previous value and set the value of pMem to be an
** empty boolean index.
*/
void sqlite3VdbeMemSetRowSet(Mem *pMem){
sqlite3 *db = pMem->db;
assert( db!=0 );
assert( (pMem->flags & MEM_RowSet)==0 );
sqlite3VdbeMemRelease(pMem);
pMem->zMalloc = sqlite3DbMallocRaw(db, 64);
if( db->mallocFailed ){
pMem->flags = MEM_Null;
}else{
assert( pMem->zMalloc );
pMem->u.pRowSet = sqlite3RowSetInit(db, pMem->zMalloc,
sqlite3DbMallocSize(db, pMem->zMalloc));
assert( pMem->u.pRowSet!=0 );
pMem->flags = MEM_RowSet;
}
}
/*
** Release any memory held by the Mem. This may leave the Mem in an
** inconsistent state, for example with (Mem.z==0) and
** (Mem.type==SQLITE_TEXT).
*/
void sqlite3VdbeMemRelease(Mem *p){
if( p->flags & (MEM_Dyn|MEM_Agg) ){
if( p->xDel ){
if( p->flags & MEM_Agg ){
sqlite3VdbeMemFinalize(p, *(FuncDef**)&p->i);
assert( (p->flags & MEM_Agg)==0 );
sqlite3VdbeMemRelease(p);
}else{
p->xDel((void *)p->z);
}
}else{
sqliteFree(p->z);
}
p->z = 0;
p->xDel = 0;
}
}
/*
** If pMem is an object with a valid string representation, this routine
** ensures the internal encoding for the string representation is
** 'desiredEnc', one of SQLITE_UTF8, SQLITE_UTF16LE or SQLITE_UTF16BE.
**
** If pMem is not a string object, or the encoding of the string
** representation is already stored using the requested encoding, then this
** routine is a no-op.
**
** SQLITE_OK is returned if the conversion is successful (or not required).
** SQLITE_NOMEM may be returned if a malloc() fails during conversion
** between formats.
*/
int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
int rc;
if( !(pMem->flags&MEM_Str) || pMem->enc==desiredEnc ){
return SQLITE_OK;
}
#ifdef SQLITE_OMIT_UTF16
return SQLITE_ERROR;
#else
rc = sqlite3VdbeMemTranslate(pMem, desiredEnc);
if( rc==SQLITE_NOMEM ){
sqlite3VdbeMemRelease(pMem);
pMem->flags = MEM_Null;
pMem->z = 0;
}
return rc;
#endif
}
/*
** Delete any previous value and set the value to be a BLOB of length
** n containing all zeros.
*/
void sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){
sqlite3VdbeMemRelease(pMem);
pMem->flags = MEM_Blob|MEM_Zero;
pMem->type = SQLITE_BLOB;
pMem->n = 0;
if( n<0 ) n = 0;
pMem->u.nZero = n;
pMem->enc = SQLITE_UTF8;
#ifdef SQLITE_OMIT_INCRBLOB
sqlite3VdbeMemGrow(pMem, n, 0);
if( pMem->z ){
pMem->n = n;
memset(pMem->z, 0, n);
}
#endif
}
/*
** If the memory cell contains a string value that must be freed by
** invoking an external callback, free it now. Calling this function
** does not free any Mem.zMalloc buffer.
*/
void sqlite3VdbeMemReleaseExternal(Mem *p){
assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
if( p->flags&MEM_Agg ){
sqlite3VdbeMemFinalize(p, p->u.pDef);
assert( (p->flags & MEM_Agg)==0 );
sqlite3VdbeMemRelease(p);
}else if( p->flags&MEM_Dyn && p->xDel ){
assert( (p->flags&MEM_RowSet)==0 );
assert( p->xDel!=SQLITE_DYNAMIC );
p->xDel((void *)p->z);
p->xDel = 0;
}else if( p->flags&MEM_RowSet ){
sqlite3RowSetClear(p->u.pRowSet);
}else if( p->flags&MEM_Frame ){
sqlite3VdbeMemSetNull(p);
}
}
/*
** 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;
}
/*
** Transfer the contents of pFrom to pTo. Any existing value in pTo is
** freed. If pFrom contains ephemeral data, a copy is made.
**
** pFrom contains an SQL NULL when this routine returns. SQLITE_NOMEM
** might be returned if pFrom held ephemeral data and we were unable
** to allocate enough space to make a copy.
*/
int sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom) {
int rc;
if( pTo->flags & MEM_Dyn ) {
sqlite3VdbeMemRelease(pTo);
}
memcpy(pTo, pFrom, sizeof(Mem));
if( pFrom->flags & MEM_Short ) {
pTo->z = pTo->zShort;
}
pFrom->flags = MEM_Null;
pFrom->xDel = 0;
if( pTo->flags & MEM_Ephem ) {
rc = sqlite3VdbeMemMakeWriteable(pTo);
} else {
rc = SQLITE_OK;
}
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;
#if SQLITE_THREADSAFE
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;
}
if( p->isPrepareV2 && p->expmask ){
p->expired = 1;
}
sqlite3_mutex_leave(mutex);
return rc;
}
/*
** Release any memory held by the Mem. This may leave the Mem in an
** inconsistent state, for example with (Mem.z==0) and
** (Mem.type==SQLITE_TEXT).
*/
void sqlite3VdbeMemRelease(Mem *p){
assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
if( p->flags & (MEM_Dyn|MEM_Agg) ){
if( p->xDel ){
if( p->flags & MEM_Agg ){
sqlite3VdbeMemFinalize(p, p->u.pDef);
assert( (p->flags & MEM_Agg)==0 );
sqlite3VdbeMemRelease(p);
}else{
p->xDel((void *)p->z);
}
}else{
sqlite3_free(p->z);
}
p->z = 0;
p->xDel = 0;
}
}
/*
** Convert pMem so that it has types MEM_Real or MEM_Int or both.
** Invalidate any prior representations.
*/
int sqlite3VdbeMemNumerify(Mem *pMem){
double r1, r2;
i64 i;
assert( (pMem->flags & (MEM_Int|MEM_Real|MEM_Null))==0 );
assert( (pMem->flags & (MEM_Blob|MEM_Str))!=0 );
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
r1 = sqlite3VdbeRealValue(pMem);
i = (i64)r1;
r2 = (double)i;
if( r1==r2 ){
sqlite3VdbeMemIntegerify(pMem);
}else{
pMem->r = r1;
pMem->flags = MEM_Real;
sqlite3VdbeMemRelease(pMem);
}
return SQLITE_OK;
}
/*
** 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.
**
** A successful evaluation of this routine acquires the mutex on p.
** the mutex is released if any kind of error occurs.
**
** 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( vdbeSafetyNotNull(p) ){
return SQLITE_MISUSE_BKPT;
}
sqlite3_mutex_enter(p->db->mutex);
if( p->magic!=VDBE_MAGIC_RUN || p->pc>=0 ){
sqlite3Error(p->db, SQLITE_MISUSE);
sqlite3_mutex_leave(p->db->mutex);
sqlite3_log(SQLITE_MISUSE,
"bind on a busy prepared statement: [%s]", p->zSql);
return SQLITE_MISUSE_BKPT;
}
if( i<1 || i>p->nVar ){
sqlite3Error(p->db, SQLITE_RANGE);
sqlite3_mutex_leave(p->db->mutex);
return SQLITE_RANGE;
}
i--;
pVar = &p->aVar[i];
sqlite3VdbeMemRelease(pVar);
pVar->flags = MEM_Null;
sqlite3Error(p->db, SQLITE_OK);
/* If the bit corresponding to this variable in Vdbe.expmask is set, then
** binding a new value to this variable invalidates the current query plan.
**
** IMPLEMENTATION-OF: R-48440-37595 If the specific value bound to host
** parameter in the WHERE clause might influence the choice of query plan
** for a statement, then the statement will be automatically recompiled,
** as if there had been a schema change, on the first sqlite3_step() call
** following any change to the bindings of that parameter.
*/
if( p->isPrepareV2 &&
((i<32 && p->expmask & ((u32)1 << i)) || p->expmask==0xffffffff)
){
p->expired = 1;
}
return SQLITE_OK;
}
int sqlite3VdbeMemExpandBlob(Mem *pMem){
if( pMem->flags & MEM_Zero ){
char *pNew;
int nByte;
assert( (pMem->flags & MEM_Blob)!=0 );
nByte = pMem->n + pMem->u.i;
if( nByte<=0 ) nByte = 1;
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
pNew = sqlite3DbMallocRaw(pMem->db, nByte);
if( pNew==0 ){
return SQLITE_NOMEM;
}
memcpy(pNew, pMem->z, pMem->n);
memset(&pNew[pMem->n], 0, pMem->u.i);
sqlite3VdbeMemRelease(pMem);
pMem->z = pNew;
pMem->n += pMem->u.i;
pMem->u.i = 0;
pMem->flags &= ~(MEM_Zero|MEM_Static|MEM_Ephem|MEM_Short|MEM_Term);
pMem->flags |= MEM_Dyn;
}
return SQLITE_OK;
}
/*
** Compare the values contained by the two memory cells, returning
** negative, zero or positive if pMem1 is less than, equal to, or greater
** than pMem2. Sorting order is NULL's first, followed by numbers (integers
** and reals) sorted numerically, followed by text ordered by the collating
** sequence pColl and finally blob's ordered by memcmp().
**
** Two NULL values are considered equal by this function.
*/
int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const CollSeq *pColl){
int rc;
int f1, f2;
int combined_flags;
/* Interchange pMem1 and pMem2 if the collating sequence specifies
** DESC order.
*/
f1 = pMem1->flags;
f2 = pMem2->flags;
combined_flags = f1|f2;
/* If one value is NULL, it is less than the other. If both values
** are NULL, return 0.
*/
if( combined_flags&MEM_Null ){
return (f2&MEM_Null) - (f1&MEM_Null);
}
/* If one value is a number and the other is not, the number is less.
** If both are numbers, compare as reals if one is a real, or as integers
** if both values are integers.
*/
if( combined_flags&(MEM_Int|MEM_Real) ){
if( !(f1&(MEM_Int|MEM_Real)) ){
return 1;
}
if( !(f2&(MEM_Int|MEM_Real)) ){
return -1;
}
if( (f1 & f2 & MEM_Int)==0 ){
double r1, r2;
if( (f1&MEM_Real)==0 ){
r1 = pMem1->u.i;
}else{
r1 = pMem1->r;
}
if( (f2&MEM_Real)==0 ){
r2 = pMem2->u.i;
}else{
r2 = pMem2->r;
}
if( r1<r2 ) return -1;
if( r1>r2 ) return 1;
return 0;
}else{
assert( f1&MEM_Int );
assert( f2&MEM_Int );
if( pMem1->u.i < pMem2->u.i ) return -1;
if( pMem1->u.i > pMem2->u.i ) return 1;
return 0;
}
}
/* If one value is a string and the other is a blob, the string is less.
** If both are strings, compare using the collating functions.
*/
if( combined_flags&MEM_Str ){
if( (f1 & MEM_Str)==0 ){
return 1;
}
if( (f2 & MEM_Str)==0 ){
return -1;
}
assert( pMem1->enc==pMem2->enc );
assert( pMem1->enc==SQLITE_UTF8 ||
pMem1->enc==SQLITE_UTF16LE || pMem1->enc==SQLITE_UTF16BE );
/* The collation sequence must be defined at this point, even if
** the user deletes the collation sequence after the vdbe program is
** compiled (this was not always the case).
*/
assert( !pColl || pColl->xCmp );
if( pColl ){
if( pMem1->enc==pColl->enc ){
/* The strings are already in the correct encoding. Call the
** comparison function directly */
return pColl->xCmp(pColl->pUser,pMem1->n,pMem1->z,pMem2->n,pMem2->z);
}else{
const void *v1, *v2;
int n1, n2;
Mem c1;
Mem c2;
memset(&c1, 0, sizeof(c1));
memset(&c2, 0, sizeof(c2));
sqlite3VdbeMemShallowCopy(&c1, pMem1, MEM_Ephem);
sqlite3VdbeMemShallowCopy(&c2, pMem2, MEM_Ephem);
v1 = sqlite3ValueText((sqlite3_value*)&c1, pColl->enc);
n1 = v1==0 ? 0 : c1.n;
v2 = sqlite3ValueText((sqlite3_value*)&c2, pColl->enc);
n2 = v2==0 ? 0 : c2.n;
rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);
sqlite3VdbeMemRelease(&c1);
sqlite3VdbeMemRelease(&c2);
return rc;
}
}
/* If a NULL pointer was passed as the collate function, fall through
** to the blob case and use memcmp(). */
}
/* Both values must be blobs. Compare using memcmp(). */
rc = memcmp(pMem1->z, pMem2->z, (pMem1->n>pMem2->n)?pMem2->n:pMem1->n);
if( rc==0 ){
rc = pMem1->n - pMem2->n;
}
return rc;
}
