/*
** Advance iterator pIter to the next key in its PMA. Return SQLITE_OK if
** no error occurs, or an SQLite error code if one does.
*/
static int vdbeSorterIterNext(
sqlite3 *db, /* Database handle (for sqlite3DbMalloc() ) */
VdbeSorterIter *pIter /* Iterator to advance */
){
int rc; /* Return Code */
int nRead; /* Number of bytes read */
int nRec = 0; /* Size of record in bytes */
int iOff = 0; /* Size of serialized size varint in bytes */
assert( pIter->iEof>=pIter->iReadOff );
if( pIter->iEof-pIter->iReadOff>5 ){
nRead = 5;
}else{
nRead = (int)(pIter->iEof - pIter->iReadOff);
}
if( nRead<=0 ){
/* This is an EOF condition */
vdbeSorterIterZero(db, pIter);
return SQLITE_OK;
}
rc = sqlite3OsRead(pIter->pFile, pIter->aAlloc, nRead, pIter->iReadOff);
if( rc==SQLITE_OK ){
iOff = getVarint32(pIter->aAlloc, nRec);
if( (iOff+nRec)>nRead ){
int nRead2; /* Number of extra bytes to read */
if( (iOff+nRec)>pIter->nAlloc ){
int nNew = pIter->nAlloc*2;
while( (iOff+nRec)>nNew ) nNew = nNew*2;
pIter->aAlloc = sqlite3DbReallocOrFree(db, pIter->aAlloc, nNew);
if( !pIter->aAlloc ) return SQLITE_NOMEM;
pIter->nAlloc = nNew;
}
nRead2 = iOff + nRec - nRead;
rc = sqlite3OsRead(
pIter->pFile, &pIter->aAlloc[nRead], nRead2, pIter->iReadOff+nRead
);
}
}
assert( rc!=SQLITE_OK || nRec>0 );
pIter->iReadOff += iOff+nRec;
pIter->nKey = nRec;
pIter->aKey = &pIter->aAlloc[iOff];
return rc;
}
/*
** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.
*/
void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){
VdbeSorter *pSorter = pCsr->pSorter;
if( pSorter ){
if( pSorter->aIter ){
int i;
for(i=0; i<pSorter->nTree; i++){
vdbeSorterIterZero(db, &pSorter->aIter[i]);
}
sqlite3DbFree(db, pSorter->aIter);
}
if( pSorter->pTemp1 ){
sqlite3OsCloseFree(pSorter->pTemp1);
}
vdbeSorterRecordFree(db, pSorter->pRecord);
sqlite3DbFree(db, pSorter->pUnpacked);
sqlite3DbFree(db, pSorter);
pCsr->pSorter = 0;
}
}
/*
** Advance iterator pIter to the next key in its PMA. Return SQLITE_OK if
** no error occurs, or an SQLite error code if one does.
*/
static int vdbeSorterIterNext(
sqlite3 *db, /* Database handle (for sqlite3DbMalloc() ) */
VdbeSorterIter *pIter /* Iterator to advance */
){
int rc; /* Return Code */
u64 nRec = 0; /* Size of record in bytes */
if( pIter->iReadOff>=pIter->iEof ){
/* This is an EOF condition */
vdbeSorterIterZero(db, pIter);
return SQLITE_OK;
}
rc = vdbeSorterIterVarint(db, pIter, &nRec);
if( rc==SQLITE_OK ){
pIter->nKey = (int)nRec;
rc = vdbeSorterIterRead(db, pIter, (int)nRec, &pIter->aKey);
}
return rc;
}
