pgq.unregister_consumer: do not raise errors

- be silent if consumer does not exist
- if subconsumers exist, unregister those too

diff --git a/sql/pgq/functions/pgq.unregister_consumer.sql b/sql/pgq/functions/pgq.unregister_consumer.sql
index 7132395a1310afc61c11122d084df13d145e8799..3cef10b6434934be33eb1672fc4808c3adf3f98a 100644 (file)
--- a/sql/pgq/functions/pgq.unregister_consumer.sql
+++ b/sql/pgq/functions/pgq.unregister_consumer.sql
@@ -20,31 +20,31 @@ declare
     x_sub_id integer;
     _sub_id_cnt integer;
 begin
-    select sub_id into x_sub_id
-        from pgq.subscription, pgq.consumer, pgq.queue
-        where sub_queue = queue_id
-          and sub_consumer = co_id
-          and queue_name = x_queue_name
-          and co_name = x_consumer_name;
+    select s.sub_id into x_sub_id
+        from pgq.subscription s, pgq.consumer c, pgq.queue q
+        where s.sub_queue = q.queue_id
+          and s.sub_consumer = c.co_id
+          and q.queue_name = x_queue_name
+          and c.co_name = x_consumer_name
+        for update of s;
     if not found then
-        raise exception 'consumer not registered on queue';
+        return 0;
     end if;
 
-    -- subconsumer-aware
+    -- consumer + subconsumer count
     select count(*) into _sub_id_cnt
         from pgq.subscription
        where sub_id = x_sub_id;
-    if _sub_id_cnt > 1 then
-        raise exception 'unregistered subconsumers detected';
-    end if;
 
+    -- retry events
     delete from pgq.retry_queue
         where ev_owner = x_sub_id;
 
+    -- this will drop subconsumers too
     delete from pgq.subscription
         where sub_id = x_sub_id;
 
-    return 1;
+    return _sub_id_cnt;
 end;
 $$ language plpgsql security definer;