Function GetUserMapping

src/backend/foreign/foreign.c:301–345

* GetUserMapping - look up the user mapping. * * If no mapping is found for the supplied user, we also look for * PUBLIC mappings (userid == InvalidOid). */

 * PUBLIC mappings (userid == InvalidOid).
 */
UserMapping *
GetUserMapping(Oid userid, Oid serverid)
{
	Datum		datum;
	HeapTuple	tp;
	bool		isnull;
	UserMapping *um;

	tp = SearchSysCache2(USERMAPPINGUSERSERVER,
						 ObjectIdGetDatum(userid),
						 ObjectIdGetDatum(serverid));

	if (!HeapTupleIsValid(tp))
	{
		/* Not found for the specific user -- try PUBLIC */
		tp = SearchSysCache2(USERMAPPINGUSERSERVER,
							 ObjectIdGetDatum(InvalidOid),
							 ObjectIdGetDatum(serverid));
	}

	if (!HeapTupleIsValid(tp))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("user mapping not found for \"%s\"",
						MappingUserName(userid))));

	um = (UserMapping *) palloc(sizeof(UserMapping));
	um->umid = ((Form_pg_user_mapping) GETSTRUCT(tp))->oid;
	um->userid = userid;
	um->serverid = serverid;

	/* Extract the umoptions */
	datum = SysCacheGetAttr(USERMAPPINGUSERSERVER,
							tp,
							Anum_pg_user_mapping_umoptions,
							&isnull);
	if (isnull)
		um->options = NIL;
	else
		um->options = untransformRelOptions(datum);

	ReleaseSysCache(tp);

	return um;
}

List *
GetForeignServerSegsByRelId(Oid relid)