Datum
gistendscan(PG_FUNCTION_ARGS)
{
IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
GISTScanOpaque so;
so = (GISTScanOpaque) scan->opaque;
if (so != NULL)
{
gistfreestack(so->stack);
gistfreestack(so->markstk);
if (so->giststate != NULL)
freeGISTstate(so->giststate);
/* drop pins on buffers -- we aren't holding any locks */
if (BufferIsValid(so->curbuf))
ReleaseBuffer(so->curbuf);
if (BufferIsValid(so->markbuf))
ReleaseBuffer(so->markbuf);
MemoryContextDelete(so->tempCxt);
pfree(scan->opaque);
}
PG_RETURN_VOID();
}
Datum
gistrestrpos(PG_FUNCTION_ARGS)
{
IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
GISTScanOpaque so;
GISTSearchStack *o,
*n,
*tmp;
scan->currentItemData = scan->currentMarkData;
so = (GISTScanOpaque) scan->opaque;
if (so->flags & GS_MRKBEFORE)
so->flags |= GS_CURBEFORE;
else
so->flags &= ~GS_CURBEFORE;
o = NULL;
n = so->markstk;
/* copy the parent stack from the current item data */
while (n != NULL)
{
tmp = (GISTSearchStack *) palloc(sizeof(GISTSearchStack));
tmp->lsn = n->lsn;
tmp->parentlsn = n->parentlsn;
tmp->block = n->block;
tmp->next = o;
o = tmp;
n = n->next;
}
gistfreestack(so->stack);
so->stack = o;
/* Update curbuf: be sure to bump ref count on markbuf */
if (BufferIsValid(so->curbuf))
{
ReleaseBuffer(so->curbuf);
so->curbuf = InvalidBuffer;
}
if (BufferIsValid(so->markbuf))
{
IncrBufferRefCount(so->markbuf);
so->curbuf = so->markbuf;
}
so->nPageData = so->markNPageData;
so->curPageData = so->markNPageData;
if ( so->markNPageData > 0 )
memcpy( so->pageData, so->markPageData, sizeof(MatchedItemPtr) * so->markNPageData );
PG_RETURN_VOID();
}
Datum
gistrescan(PG_FUNCTION_ARGS)
{
IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
ScanKey key = (ScanKey) PG_GETARG_POINTER(1);
GISTScanOpaque so;
int i;
/*
* Clear all the pointers.
*/
ItemPointerSetInvalid(&scan->currentItemData);
ItemPointerSetInvalid(&scan->currentMarkData);
so = (GISTScanOpaque) scan->opaque;
if (so != NULL)
{
/* rescan an existing indexscan --- reset state */
gistfreestack(so->stack);
gistfreestack(so->markstk);
so->stack = so->markstk = NULL;
so->flags = 0x0;
/* drop pins on buffers -- no locks held */
if (BufferIsValid(so->curbuf))
{
ReleaseBuffer(so->curbuf);
so->curbuf = InvalidBuffer;
}
if (BufferIsValid(so->markbuf))
{
ReleaseBuffer(so->markbuf);
so->markbuf = InvalidBuffer;
}
}
else
{
/* initialize opaque data */
so = (GISTScanOpaque) palloc(sizeof(GISTScanOpaqueData));
so->stack = so->markstk = NULL;
so->flags = 0x0;
so->tempCxt = createTempGistContext();
so->curbuf = so->markbuf = InvalidBuffer;
so->giststate = (GISTSTATE *) palloc(sizeof(GISTSTATE));
initGISTstate(so->giststate, scan->indexRelation);
scan->opaque = so;
}
so->nPageData = so->curPageData = 0;
/* Update scan key, if a new one is given */
if (key && scan->numberOfKeys > 0)
{
memmove(scan->keyData, key,
scan->numberOfKeys * sizeof(ScanKeyData));
/*
* Modify the scan key so that all the Consistent method is called for
* all comparisons. The original operator is passed to the Consistent
* function in the form of its strategy number, which is available
* from the sk_strategy field, and its subtype from the sk_subtype
* field.
*/
for (i = 0; i < scan->numberOfKeys; i++)
scan->keyData[i].sk_func = so->giststate->consistentFn[scan->keyData[i].sk_attno - 1];
}
PG_RETURN_VOID();
}
Datum
gistrescan(PG_FUNCTION_ARGS)
{
IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
ScanKey key = (ScanKey) PG_GETARG_POINTER(1);
GISTScanOpaque so;
int i;
so = (GISTScanOpaque) scan->opaque;
if (so != NULL)
{
/* rescan an existing indexscan --- reset state */
gistfreestack(so->stack);
so->stack = NULL;
/* drop pins on buffers -- no locks held */
if (BufferIsValid(so->curbuf))
{
ReleaseBuffer(so->curbuf);
so->curbuf = InvalidBuffer;
}
}
else
{
/* initialize opaque data */
so = (GISTScanOpaque) palloc(sizeof(GISTScanOpaqueData));
so->stack = NULL;
so->tempCxt = createTempGistContext();
so->curbuf = InvalidBuffer;
so->giststate = (GISTSTATE *) palloc(sizeof(GISTSTATE));
initGISTstate(so->giststate, scan->indexRelation);
scan->opaque = so;
}
/*
* Clear all the pointers.
*/
ItemPointerSetInvalid(&so->curpos);
so->nPageData = so->curPageData = 0;
so->qual_ok = true;
/* Update scan key, if a new one is given */
if (key && scan->numberOfKeys > 0)
{
memmove(scan->keyData, key,
scan->numberOfKeys * sizeof(ScanKeyData));
/*
* Modify the scan key so that all the Consistent method is called for
* all comparisons. The original operator is passed to the Consistent
* function in the form of its strategy number, which is available
* from the sk_strategy field, and its subtype from the sk_subtype
* field.
*
* Next, if any of keys is a NULL and that key is not marked with
* SK_SEARCHNULL/SK_SEARCHNOTNULL then nothing can be found (ie, we
* assume all indexable operators are strict).
*/
for (i = 0; i < scan->numberOfKeys; i++)
{
ScanKey skey = &(scan->keyData[i]);
skey->sk_func = so->giststate->consistentFn[skey->sk_attno - 1];
if (skey->sk_flags & SK_ISNULL)
{
if (!(skey->sk_flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL)))
so->qual_ok = false;
}
}
}
PG_RETURN_VOID();
}