void case_heap_repalce() {
struct heap *heap = heap(heap_cmp);
int a = 3, b = 2, c = 5, d = 7, e = 4, f = 6, g = 1, h = 4;
assert(heap_push(heap, (void *)&a) == HEAP_OK);
assert(heap_push(heap, (void *)&b) == HEAP_OK);
assert(heap_push(heap, (void *)&c) == HEAP_OK);
assert(heap_push(heap, (void *)&d) == HEAP_OK);
assert(heap_push(heap, (void *)&e) == HEAP_OK);
assert(heap_push(heap, (void *)&f) == HEAP_OK);
assert(heap_push(heap, (void *)&g) == HEAP_OK);
assert(1 == *(int *)heap_replace(heap, (void *)&h));
assert(2 == *(int *)heap_pop(heap));
assert(3 == *(int *)heap_pop(heap));
assert(4 == *(int *)heap_pop(heap));
heap_free(heap);
}
int32
RelationPurge(char *relationName,
char *absoluteTimeString,
char *relativeTimeString)
{
register i;
AbsoluteTime absoluteTime = INVALID_ABSTIME;
RelativeTime relativeTime = INVALID_RELTIME;
bits8 dateTag;
Relation relation;
HeapScanDesc scan;
static ScanKeyData key[1] = {
{ 0, Anum_pg_class_relname, F_NAMEEQ }
};
Buffer buffer;
HeapTuple newTuple, oldTuple;
AbsoluteTime currentTime;
char *values[Natts_pg_class];
char nulls[Natts_pg_class];
char replace[Natts_pg_class];
Relation idescs[Num_pg_class_indices];
/*
* XXX for some reason getmyrelids (in inval.c) barfs when
* you heap_replace tuples from these classes. i thought
* setheapoverride would fix it but it didn't. for now,
* just disallow purge on these classes.
*/
if (strcmp(RelationRelationName, relationName) == 0 ||
strcmp(AttributeRelationName, relationName) == 0 ||
strcmp(AccessMethodRelationName, relationName) == 0 ||
strcmp(AccessMethodOperatorRelationName, relationName) == 0) {
elog(WARN, "%s: cannot purge catalog \"%s\"",
cmdname, relationName);
}
if (PointerIsValid(absoluteTimeString)) {
absoluteTime = (int32) nabstimein(absoluteTimeString);
absoluteTimeString[0] = '\0';
if (absoluteTime == INVALID_ABSTIME) {
elog(NOTICE, "%s: bad absolute time string \"%s\"",
cmdname, absoluteTimeString);
elog(WARN, "purge not executed");
}
}
#ifdef PURGEDEBUG
elog(DEBUG, "%s: absolute time `%s' is %d.",
cmdname, absoluteTimeString, absoluteTime);
#endif /* defined(PURGEDEBUG) */
if (PointerIsValid(relativeTimeString)) {
if (isreltime(relativeTimeString, NULL, NULL, NULL) != 1) {
elog(WARN, "%s: bad relative time string \"%s\"",
cmdname, relativeTimeString);
}
relativeTime = reltimein(relativeTimeString);
#ifdef PURGEDEBUG
elog(DEBUG, "%s: relative time `%s' is %d.",
cmdname, relativeTimeString, relativeTime);
#endif /* defined(PURGEDEBUG) */
}
/*
* Find the RELATION relation tuple for the given relation.
*/
relation = heap_openr(RelationRelationName);
key[0].sk_argument = PointerGetDatum(relationName);
fmgr_info(key[0].sk_procedure, &key[0].sk_func, &key[0].sk_nargs);
scan = heap_beginscan(relation, 0, NowTimeQual, 1, key);
oldTuple = heap_getnext(scan, 0, &buffer);
if (!HeapTupleIsValid(oldTuple)) {
heap_endscan(scan);
heap_close(relation);
elog(WARN, "%s: no such relation: %s", cmdname, relationName);
return(0);
}
/*
* Dig around in the tuple.
*/
currentTime = GetCurrentTransactionStartTime();
if (!RelativeTimeIsValid(relativeTime)) {
dateTag = ABSOLUTE;
if (!AbsoluteTimeIsValid(absoluteTime))
absoluteTime = currentTime;
} else if (!AbsoluteTimeIsValid(absoluteTime))
dateTag = RELATIVE;
else
dateTag = ABSOLUTE | RELATIVE;
for (i = 0; i < Natts_pg_class; ++i) {
nulls[i] = heap_attisnull(oldTuple, i+1) ? 'n' : ' ';
values[i] = NULL;
replace[i] = ' ';
}
if (dateTag & ABSOLUTE) {
values[Anum_pg_class_relexpires-1] =
(char *) UInt32GetDatum(absoluteTime);
replace[Anum_pg_class_relexpires-1] = 'r';
}
if (dateTag & RELATIVE) {
values[Anum_pg_class_relpreserved-1] =
(char *) UInt32GetDatum(relativeTime);
replace[Anum_pg_class_relpreserved-1] = 'r';
}
/*
* Change the RELATION relation tuple for the given relation.
*/
newTuple = heap_modifytuple(oldTuple, buffer, relation, (Datum*)values,
nulls, replace);
/* XXX How do you detect an insertion error?? */
(void) heap_replace(relation, &newTuple->t_ctid, newTuple);
/* keep the system catalog indices current */
CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, idescs);
CatalogIndexInsert(idescs, Num_pg_class_indices, relation, newTuple);
CatalogCloseIndices(Num_pg_class_indices, idescs);
pfree(newTuple);
heap_endscan(scan);
heap_close(relation);
return(1);
}
