Function TriggerEnabled

src/backend/commands/trigger.c:3218–3315

* Is trigger enabled to fire? */

 * Is trigger enabled to fire?
 */
static bool
TriggerEnabled(EState *estate, ResultRelInfo *relinfo,
			   Trigger *trigger, TriggerEvent event,
			   Bitmapset *modifiedCols,
			   TupleTableSlot *oldslot, TupleTableSlot *newslot)
{
	/* Check replication-role-dependent enable state */
	if (SessionReplicationRole == SESSION_REPLICATION_ROLE_REPLICA)
	{
		if (trigger->tgenabled == TRIGGER_FIRES_ON_ORIGIN ||
			trigger->tgenabled == TRIGGER_DISABLED)
			return false;
	}
	else						/* ORIGIN or LOCAL role */
	{
		if (trigger->tgenabled == TRIGGER_FIRES_ON_REPLICA ||
			trigger->tgenabled == TRIGGER_DISABLED)
			return false;
	}

	/*
	 * Check for column-specific trigger (only possible for UPDATE, and in
	 * fact we *must* ignore tgattr for other event types)
	 */
	if (trigger->tgnattr > 0 && TRIGGER_FIRED_BY_UPDATE(event))
	{
		int			i;
		bool		modified;

		modified = false;
		for (i = 0; i < trigger->tgnattr; i++)
		{
			if (bms_is_member(trigger->tgattr[i] - FirstLowInvalidHeapAttributeNumber,
							  modifiedCols))
			{
				modified = true;
				break;
			}
		}
		if (!modified)
			return false;
	}

	/* Check for WHEN clause */
	if (trigger->tgqual)
	{
		ExprState **predicate;
		ExprContext *econtext;
		MemoryContext oldContext;
		int			i;

		Assert(estate != NULL);

		/*
		 * trigger is an element of relinfo->ri_TrigDesc->triggers[]; find the
		 * matching element of relinfo->ri_TrigWhenExprs[]
		 */
		i = trigger - relinfo->ri_TrigDesc->triggers;