/*
* Return the offset of the next matching index entry. We begin the
* search at offset "n" and search for matches in the direction
* "dir". If no more matching entries are found on the page,
* InvalidOffsetNumber is returned.
*/
static OffsetNumber
findnext(IndexScanDesc s, OffsetNumber n, ScanDirection dir)
{
OffsetNumber maxoff;
IndexTuple it;
RTreePageOpaque po;
RTreeScanOpaque so;
Page p;
so = (RTreeScanOpaque) s->opaque;
p = BufferGetPage(so->curbuf);
maxoff = PageGetMaxOffsetNumber(p);
po = (RTreePageOpaque) PageGetSpecialPointer(p);
/*
* If we modified the index during the scan, we may have a pointer to a
* ghost tuple, before the scan. If this is the case, back up one.
*/
if (so->s_flags & RTS_CURBEFORE)
{
so->s_flags &= ~RTS_CURBEFORE;
n = OffsetNumberPrev(n);
}
while (n >= FirstOffsetNumber && n <= maxoff)
{
it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
if (po->flags & F_LEAF)
{
if (index_keytest(it,
RelationGetDescr(s->indexRelation),
s->numberOfKeys, s->keyData))
break;
}
else
{
if (index_keytest(it,
RelationGetDescr(s->indexRelation),
so->s_internalNKey, so->s_internalKey))
break;
}
if (ScanDirectionIsBackward(dir))
n = OffsetNumberPrev(n);
else
n = OffsetNumberNext(n);
}
if (n >= FirstOffsetNumber && n <= maxoff)
return n; /* found a match on this page */
else
return InvalidOffsetNumber; /* no match, go to next page */
}
/*
* _hash_checkqual -- does the index tuple satisfy the scan conditions?
*/
bool
_hash_checkqual(IndexScanDesc scan, IndexTuple itup)
{
return index_keytest(itup, RelationGetDescr(scan->indexRelation),
scan->numberOfKeys, scan->keyData);
}
