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/*-------------------------------------------------------------------------
*
* heapvalid.c--
* heap tuple qualification validity checking code
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/common/Attic/heapvalid.c,v 1.3 1996/10/19 04:51:34 scrappy Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/htup.h"
#include "access/skey.h"
#include "storage/buf.h"
#include "storage/itemid.h"
#include "utils/rel.h"
#include "storage/bufpage.h"
#include "utils/tqual.h"
/* ----------------
* heap_keytest
*
* Test a heap tuple with respect to a scan key.
* ----------------
*/
bool
heap_keytest(HeapTuple t,
TupleDesc tupdesc,
int nkeys,
ScanKey keys)
{
bool isnull;
Datum atp;
int test;
for (; nkeys--; keys++) {
atp = (Datum)heap_getattr(t, InvalidBuffer,
keys->sk_attno,
tupdesc,
&isnull);
if (isnull)
/* XXX eventually should check if SK_ISNULL */
return false;
if (keys->sk_flags & SK_COMMUTE)
test = (long) FMGR_PTR2(keys->sk_func, keys->sk_procedure,
keys->sk_argument, atp);
else
test = (long) FMGR_PTR2(keys->sk_func, keys->sk_procedure,
atp, keys->sk_argument);
if (!test == !(keys->sk_flags & SK_NEGATE))
return false;
}
return true;
}
/* ----------------
* heap_tuple_satisfies
*
* Returns a valid HeapTuple if it satisfies the timequal and keytest.
* Returns NULL otherwise. Used to be heap_satisifies (sic) which
* returned a boolean. It now returns a tuple so that we can avoid doing two
* PageGetItem's per tuple.
*
* Complete check of validity including LP_CTUP and keytest.
* This should perhaps be combined with valid somehow in the
* future. (Also, additional rule tests/time range tests.)
*
* on 8/21/92 mao says: i rearranged the tests here to do keytest before
* SatisfiesTimeQual. profiling indicated that even for vacuumed relations,
* time qual checking was more expensive than key testing. time qual is
* least likely to fail, too. we should really add the time qual test to
* the restriction and optimize it in the normal way. this has interactions
* with joey's expensive function work.
* ----------------
*/
HeapTuple
heap_tuple_satisfies(ItemId itemId,
Relation relation,
PageHeader disk_page,
TimeQual qual,
int nKeys,
ScanKey key)
{
HeapTuple tuple;
bool res;
if (! ItemIdIsUsed(itemId))
return NULL;
tuple = (HeapTuple) PageGetItem((Page) disk_page, itemId);
if (key != NULL)
res = heap_keytest(tuple, RelationGetTupleDescriptor(relation),
nKeys, key);
else
res = TRUE;
if (res && (relation->rd_rel->relkind == RELKIND_UNCATALOGED
|| HeapTupleSatisfiesTimeQual(tuple,qual)))
return tuple;
return (HeapTuple) NULL;
}
/*
* TupleUpdatedByCurXactAndCmd() -- Returns true if this tuple has
* already been updated once by the current transaction/command
* pair.
*/
bool
TupleUpdatedByCurXactAndCmd(HeapTuple t)
{
if (TransactionIdEquals(t->t_xmax,
GetCurrentTransactionId()) &&
t->t_cmax == GetCurrentCommandId())
return true;
return false;
}
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