/*
* shdepChangeDep
*
* Update shared dependency records to account for an updated referenced
* object. This is an internal workhorse for operations such as changing
* an object's owner.
*
* There must be no more than one existing entry for the given dependent
* object and dependency type! So in practice this can only be used for
* updating SHARED_DEPENDENCY_OWNER entries, which should have that property.
*
* If there is no previous entry, we assume it was referencing a PINned
* object, so we create a new entry. If the new referenced object is
* PINned, we don't create an entry (and drop the old one, if any).
*
* sdepRel must be the pg_shdepend relation, already opened and suitably
* locked.
*/
static void
shdepChangeDep(Relation sdepRel,
Oid classid, Oid objid, int32 objsubid,
Oid refclassid, Oid refobjid,
SharedDependencyType deptype)
{
Oid dbid = classIdGetDbId(classid);
HeapTuple oldtup = NULL;
HeapTuple scantup;
ScanKeyData key[4];
SysScanDesc scan;
/*
* Make sure the new referenced object doesn't go away while we record the
* dependency.
*/
shdepLockAndCheckObject(refclassid, refobjid);
/*
* Look for a previous entry
*/
ScanKeyInit(&key[0],
Anum_pg_shdepend_dbid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(dbid));
ScanKeyInit(&key[1],
Anum_pg_shdepend_classid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(classid));
ScanKeyInit(&key[2],
Anum_pg_shdepend_objid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(objid));
ScanKeyInit(&key[3],
Anum_pg_shdepend_objsubid,
BTEqualStrategyNumber, F_INT4EQ,
Int32GetDatum(objsubid));
scan = systable_beginscan(sdepRel, SharedDependDependerIndexId, true,
NULL, 4, key);
while ((scantup = systable_getnext(scan)) != NULL)
{
/* Ignore if not of the target dependency type */
if (((Form_pg_shdepend) GETSTRUCT(scantup))->deptype != deptype)
continue;
/* Caller screwed up if multiple matches */
if (oldtup)
elog(ERROR,
"multiple pg_shdepend entries for object %u/%u/%d deptype %c",
classid, objid, objsubid, deptype);
oldtup = heap_copytuple(scantup);
}
systable_endscan(scan);
if (isSharedObjectPinned(refclassid, refobjid, sdepRel))
{
/* No new entry needed, so just delete existing entry if any */
if (oldtup)
CatalogTupleDelete(sdepRel, &oldtup->t_self);
}
else if (oldtup)
{
/* Need to update existing entry */
Form_pg_shdepend shForm = (Form_pg_shdepend) GETSTRUCT(oldtup);
/* Since oldtup is a copy, we can just modify it in-memory */
shForm->refclassid = refclassid;
shForm->refobjid = refobjid;
CatalogTupleUpdate(sdepRel, &oldtup->t_self, oldtup);
}
else
{
/* Need to insert new entry */
Datum values[Natts_pg_shdepend];
bool nulls[Natts_pg_shdepend];
memset(nulls, false, sizeof(nulls));
values[Anum_pg_shdepend_dbid - 1] = ObjectIdGetDatum(dbid);
values[Anum_pg_shdepend_classid - 1] = ObjectIdGetDatum(classid);
values[Anum_pg_shdepend_objid - 1] = ObjectIdGetDatum(objid);
values[Anum_pg_shdepend_objsubid - 1] = Int32GetDatum(objsubid);
values[Anum_pg_shdepend_refclassid - 1] = ObjectIdGetDatum(refclassid);
values[Anum_pg_shdepend_refobjid - 1] = ObjectIdGetDatum(refobjid);
values[Anum_pg_shdepend_deptype - 1] = CharGetDatum(deptype);
/*
* we are reusing oldtup just to avoid declaring a new variable, but
* it's certainly a new tuple
*/
oldtup = heap_form_tuple(RelationGetDescr(sdepRel), values, nulls);
CatalogTupleInsert(sdepRel, oldtup);
}
if (oldtup)
heap_freetuple(oldtup);
}
/*
* shdepChangeDep
*
* Update shared dependency records to account for an updated referenced
* object. This is an internal workhorse for operations such as changing
* an object's owner.
*
* There must be no more than one existing entry for the given dependent
* object and dependency type! So in practice this can only be used for
* updating SHARED_DEPENDENCY_OWNER entries, which should have that property.
*
* If there is no previous entry, we assume it was referencing a PINned
* object, so we create a new entry. If the new referenced object is
* PINned, we don't create an entry (and drop the old one, if any).
*
* sdepRel must be the pg_shdepend relation, already opened and suitably
* locked.
*/
static void
shdepChangeDep(Relation sdepRel, Oid classid, Oid objid,
Oid refclassid, Oid refobjid,
SharedDependencyType deptype)
{
Oid dbid = classIdGetDbId(classid);
bool bGotOne = false;
HeapTuple oldtup = NULL;
HeapTuple scantup;
cqContext *pcqCtx;
cqContext cqc;
/*
* Make sure the new referenced object doesn't go away while we record the
* dependency.
*/
shdepLockAndCheckObject(refclassid, refobjid);
/*
* Look for a previous entry
*/
pcqCtx = caql_beginscan(
caql_addrel(cqclr(&cqc), sdepRel),
cql("SELECT * FROM pg_shdepend "
" WHERE dbid = :1 "
" AND classid = :2 "
" AND objid = :3 "
" FOR UPDATE ",
ObjectIdGetDatum(dbid),
ObjectIdGetDatum(classid),
ObjectIdGetDatum(objid)));
while (HeapTupleIsValid(scantup = caql_getnext(pcqCtx)))
{
/* Ignore if not of the target dependency type */
if (((Form_pg_shdepend) GETSTRUCT(scantup))->deptype != deptype)
continue;
/* Caller screwed up if multiple matches */
if (bGotOne)
elog(ERROR,
"multiple pg_shdepend entries for object %u/%u deptype %c",
classid, objid, deptype);
bGotOne = true;
}
caql_endscan(pcqCtx);
/* XXX XXX XXX XXX XXX XXX XXX XXX XXX
* Should match this logic:
*
* if isSharedObjectpinned
* if Gotone then drop it
* else
* if Gotone
* then update it
* else insert it
*
* XXX XXX XXX XXX XXX XXX XXX XXX XXX
*/
if (!bGotOne) /* no match */
{
/* if no match and pinned, new entry not needed */
if (isSharedObjectPinned(refclassid, refobjid, sdepRel))
{
/* just return -- don't need to free anything because
* sdelRel was passed in, and pcqCtx is freed
*/
return;
}
pcqCtx = caql_beginscan(
caql_addrel(cqclr(&cqc), sdepRel),
cql("INSERT INTO pg_shdepend ",
NULL));
/* Need to insert new entry */
Datum values[Natts_pg_shdepend];
bool nulls[Natts_pg_shdepend];
memset(nulls, 0, sizeof(nulls));
values[Anum_pg_shdepend_dbid - 1] = ObjectIdGetDatum(dbid);
values[Anum_pg_shdepend_classid - 1] = ObjectIdGetDatum(classid);
values[Anum_pg_shdepend_objid - 1] = ObjectIdGetDatum(objid);
values[Anum_pg_shdepend_refclassid - 1] = ObjectIdGetDatum(refclassid);
values[Anum_pg_shdepend_refobjid - 1] = ObjectIdGetDatum(refobjid);
values[Anum_pg_shdepend_deptype - 1] = CharGetDatum(deptype);
/*
* we are reusing oldtup just to avoid declaring a new variable, but
* it's certainly a new tuple
*/
oldtup = caql_form_tuple(pcqCtx, values, nulls);
caql_insert(pcqCtx, oldtup);
/* and Update indexes (implicit) */
heap_freetuple(oldtup);
caql_endscan(pcqCtx);
}
else
{
/* XXX XXX Do the scan again, but do the update/delete this time */
pcqCtx = caql_beginscan(
caql_addrel(cqclr(&cqc), sdepRel),
cql("SELECT * FROM pg_shdepend "
" WHERE dbid = :1 "
" AND classid = :2 "
" AND objid = :3 "
" FOR UPDATE ",
ObjectIdGetDatum(dbid),
ObjectIdGetDatum(classid),
ObjectIdGetDatum(objid)));
while (HeapTupleIsValid(scantup = caql_getnext(pcqCtx)))
{
/* Ignore if not of the target dependency type */
if (((Form_pg_shdepend) GETSTRUCT(scantup))->deptype != deptype)
continue;
/*
* NOTE: already tested for multiple matches - just use
* first one
*/
if (isSharedObjectPinned(refclassid, refobjid, sdepRel))
{
/* No new entry needed, so just delete existing entry if any */
caql_delete_current(pcqCtx);
}
else
{
oldtup = heap_copytuple(scantup);
/* Need to update existing entry */
Form_pg_shdepend shForm = (Form_pg_shdepend) GETSTRUCT(oldtup);
/* Since oldtup is a copy, we can just modify it in-memory */
shForm->refclassid = refclassid;
shForm->refobjid = refobjid;
caql_update_current(pcqCtx, oldtup);
/* and Update indexes (implicit) */
heap_freetuple(oldtup);
}
break;
}
caql_endscan(pcqCtx);
}
}
