Function AfterTriggerFreeQuery

src/backend/commands/trigger.c:4859–4900

* AfterTriggerFreeQuery * Release subsidiary storage for a trigger query level. * This includes closing down tuplestores. * Note: it's important for this to be safe if interrupted by an error * and then called again for the same query level. */

 *	and then called again for the same query level.
 */
static void
AfterTriggerFreeQuery(AfterTriggersQueryData *qs)
{
	Tuplestorestate *ts;
	List	   *tables;
	ListCell   *lc;

	/* Drop the trigger events */
	afterTriggerFreeEventList(&qs->events);

	/* Drop FDW tuplestore if any */
	ts = qs->fdw_tuplestore;
	qs->fdw_tuplestore = NULL;
	if (ts)
		tuplestore_end(ts);

	/* Release per-table subsidiary storage */
	tables = qs->tables;
	foreach(lc, tables)
	{
		AfterTriggersTableData *table = (AfterTriggersTableData *) lfirst(lc);

		ts = table->old_tuplestore;
		table->old_tuplestore = NULL;
		if (ts)
			release_or_prolong_tuplestore(ts, table->prolonged);
		ts = table->new_tuplestore;
		table->new_tuplestore = NULL;
		if (ts)
			release_or_prolong_tuplestore(ts, table->prolonged);
		if (table->storeslot)
			ExecDropSingleTupleTableSlot(table->storeslot);
	}

	/*
	 * Now free the AfterTriggersTableData structs and list cells.  Reset list
	 * pointer first; if list_free_deep somehow gets an error, better to leak
	 * that storage than have an infinite loop.
	 */
	qs->tables = NIL;
	list_free_deep(tables);
}

/*
 * Release the tuplestore, or append it to the prolonged tuplestores list.