/*
** Add MEM_Str to the set of representations for the given Mem. Numbers
** are converted using sqlite3_snprintf(). Converting a BLOB to a string
** is a no-op.
**
** Existing representations MEM_Int and MEM_Real are *not* invalidated.
**
** A MEM_Null value will never be passed to this function. This function is
** used for converting values to text for returning to the user (i.e. via
** sqlite3_value_text()), or for ensuring that values to be used as btree
** keys are strings. In the former case a NULL pointer is returned the
** user and the later is an internal programming error.
*/
int sqlite3VdbeMemStringify(Mem *pMem, int enc){
int rc = SQLITE_OK;
int fg = pMem->flags;
const int nByte = 32;
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
assert( !(fg&MEM_Zero) );
assert( !(fg&(MEM_Str|MEM_Blob)) );
assert( fg&(MEM_Int|MEM_Real) );
if( sqlite3VdbeMemGrow(pMem, nByte, 0) ){
return SQLITE_NOMEM;
}
/* For a Real or Integer, use sqlite3_mprintf() to produce the UTF-8
** string representation of the value. Then, if the required encoding
** is UTF-16le or UTF-16be do a translation.
**
** FIX ME: It would be better if sqlite3_snprintf() could do UTF-16.
*/
if( fg & MEM_Int ){
sqlite3_snprintf(nByte, pMem->z, "%lld", pMem->u.i);
}else{
assert( fg & MEM_Real );
sqlite3_snprintf(nByte, pMem->z, "%!.15g", pMem->r);
}
pMem->n = strlen(pMem->z);
pMem->enc = SQLITE_UTF8;
pMem->flags |= MEM_Str|MEM_Term;
sqlite3VdbeChangeEncoding(pMem, enc);
return rc;
}
/*
** Make sure the given Mem is \u0000 terminated.
*/
int sqlite3VdbeMemNulTerminate(Mem *pMem){
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
if( (pMem->flags & MEM_Term)!=0 || (pMem->flags & MEM_Str)==0 ){
return SQLITE_OK; /* Nothing to do */
}
if( sqlite3VdbeMemGrow(pMem, pMem->n+2, 1) ){
return SQLITE_NOMEM;
}
pMem->z[pMem->n] = 0;
pMem->z[pMem->n+1] = 0;
pMem->flags |= MEM_Term;
return SQLITE_OK;
}
/*
** Copy the current sorter key into the memory cell pOut.
*/
int sqlite3VdbeSorterRowkey(VdbeCursor *pCsr, Mem *pOut){
VdbeSorter *pSorter = pCsr->pSorter;
void *pKey; int nKey; /* Sorter key to copy into pOut */
pKey = vdbeSorterRowkey(pSorter, &nKey);
if( sqlite3VdbeMemGrow(pOut, nKey, 0) ){
return SQLITE_NOMEM;
}
pOut->n = nKey;
MemSetTypeFlag(pOut, MEM_Blob);
memcpy(pOut->z, pKey, nKey);
return SQLITE_OK;
}
/*
** Make the given Mem object MEM_Dyn. In other words, make it so
** that any TEXT or BLOB content is stored in memory obtained from
** malloc(). In this way, we know that the memory is safe to be
** overwritten or altered.
**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
int sqlite3VdbeMemMakeWriteable(Mem *pMem){
int f;
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
expandBlob(pMem);
f = pMem->flags;
if( (f&(MEM_Str|MEM_Blob)) && pMem->z!=pMem->zMalloc ){
if( sqlite3VdbeMemGrow(pMem, pMem->n + 2, 1) ){
return SQLITE_NOMEM;
}
pMem->z[pMem->n] = 0;
pMem->z[pMem->n+1] = 0;
pMem->flags |= MEM_Term;
}
return SQLITE_OK;
}
/*
** 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;
}
/*
** 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
}
/*
** 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;
}
/*
** Make the given Mem object MEM_Dyn. In other words, make it so
** that any TEXT or BLOB content is stored in memory obtained from
** malloc(). In this way, we know that the memory is safe to be
** overwritten or altered.
**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
int sqlite3VdbeMemMakeWriteable(Mem *pMem){
int f;
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
assert( (pMem->flags&MEM_RowSet)==0 );
ExpandBlob(pMem);
f = pMem->flags;
if( (f&(MEM_Str|MEM_Blob)) && pMem->z!=pMem->zMalloc ){
if( sqlite3VdbeMemGrow(pMem, pMem->n + 2, 1) ){
return SQLITE_NOMEM;
}
pMem->z[pMem->n] = 0;
pMem->z[pMem->n+1] = 0;
pMem->flags |= MEM_Term;
#ifdef SQLITE_DEBUG
pMem->pScopyFrom = 0;
#endif
}
return SQLITE_OK;
}
int sqlite3VdbeMemExpandBlob(Mem *pMem){
if( pMem->flags & MEM_Zero ){
int nByte;
assert( pMem->flags&MEM_Blob );
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
/* Set nByte to the number of bytes required to store the expanded blob. */
nByte = pMem->n + pMem->u.i;
if( nByte<=0 ){
nByte = 1;
}
if( sqlite3VdbeMemGrow(pMem, nByte, 1) ){
return SQLITE_NOMEM;
}
memset(&pMem->z[pMem->n], 0, pMem->u.i);
pMem->n += pMem->u.i;
pMem->flags &= ~(MEM_Zero|MEM_Term);
}
return SQLITE_OK;
}
/*
** 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;
}
/*
** Change the value of a Mem to be a string or a BLOB.
**
** The memory management strategy depends on the value of the xDel
** parameter. If the value passed is SQLITE_TRANSIENT, then the
** string is copied into a (possibly existing) buffer managed by the
** Mem structure. Otherwise, any existing buffer is freed and the
** pointer copied.
*/
int sqlite3VdbeMemSetStr(
Mem *pMem, /* Memory cell to set to string value */
const char *z, /* String pointer */
int n, /* Bytes in string, or negative */
u8 enc, /* Encoding of z. 0 for BLOBs */
void (*xDel)(void*) /* Destructor function */
){
int nByte = n; /* New value for pMem->n */
int iLimit; /* Maximum allowed string or blob size */
int flags = 0; /* New value for pMem->flags */
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
/* If z is a NULL pointer, set pMem to contain an SQL NULL. */
if( !z ){
sqlite3VdbeMemSetNull(pMem);
return SQLITE_OK;
}
if( pMem->db ){
iLimit = pMem->db->aLimit[SQLITE_LIMIT_LENGTH];
}else{
iLimit = SQLITE_MAX_LENGTH;
}
flags = (enc==0?MEM_Blob:MEM_Str);
if( nByte<0 ){
assert( enc!=0 );
if( enc==SQLITE_UTF8 ){
for(nByte=0; nByte<=iLimit && z[nByte]; nByte++){}
}else{
for(nByte=0; nByte<=iLimit && (z[nByte] | z[nByte+1]); nByte+=2){}
}
flags |= MEM_Term;
}
/* The following block sets the new values of Mem.z and Mem.xDel. It
** also sets a flag in local variable "flags" to indicate the memory
** management (one of MEM_Dyn or MEM_Static).
*/
if( xDel==SQLITE_TRANSIENT ){
int nAlloc = nByte;
if( flags&MEM_Term ){
nAlloc += (enc==SQLITE_UTF8?1:2);
}
if( nByte>iLimit ){
return SQLITE_TOOBIG;
}
if( sqlite3VdbeMemGrow(pMem, nAlloc, 0) ){
return SQLITE_NOMEM;
}
memcpy(pMem->z, z, nAlloc);
}else if( xDel==SQLITE_DYNAMIC ){
sqlite3VdbeMemRelease(pMem);
pMem->zMalloc = pMem->z = (char *)z;
pMem->xDel = 0;
}else{
sqlite3VdbeMemRelease(pMem);
pMem->z = (char *)z;
pMem->xDel = xDel;
flags |= ((xDel==SQLITE_STATIC)?MEM_Static:MEM_Dyn);
}
if( nByte>iLimit ){
return SQLITE_TOOBIG;
}
pMem->n = nByte;
pMem->flags = flags;
pMem->enc = (enc==0 ? SQLITE_UTF8 : enc);
pMem->type = (enc==0 ? SQLITE_BLOB : SQLITE_TEXT);
#ifndef SQLITE_OMIT_UTF16
if( pMem->enc!=SQLITE_UTF8 && sqlite3VdbeMemHandleBom(pMem) ){
return SQLITE_NOMEM;
}
#endif
return SQLITE_OK;
}
