Add fanout exchange-type and create amq.fanout exchange at startup

amqp_relay.ml

@@ -384,4 +384,7 @@ let init () =
   Node.send_ignore "factory" (Message.create (Sexp.Str "direct",
 					      Sexp.Arr [Sexp.Str "amq.direct"],
 					      Sexp.Str "", Sexp.Str ""));
+  Node.send_ignore "factory" (Message.create (Sexp.Str "fanout",
+					      Sexp.Arr [Sexp.Str "amq.fanout"],
+					      Sexp.Str "", Sexp.Str ""));
   ignore (Util.create_thread "AMQP listener" None (Net.start_net Amqp_spec.port) start)

fanoutnode.ml

@@ -0,0 +1,47 @@
+open Sexp
+open Datastructures
+open Status
+
+type t = {
+    name: string;
+    subscriptions: Subscription.set_t;
+    mtx: Mutex.t;
+  }
+
+let classname = "fanout"
+
+let unsubscribe info uuid =
+  Util.with_mutex0 info.mtx
+    (fun () -> ignore (Subscription.delete info.subscriptions uuid))
+
+let route_message info n sexp =
+  match Message.message_of_sexp sexp with
+  | Message.Post (Str name, body, token) ->
+      let snapshot = !(info.subscriptions) in
+      StringMap.iter
+	(fun uuid sub ->
+	  ignore (Subscription.send_to_subscription' sub body (unsubscribe info)))
+	snapshot
+  | Message.Subscribe (Str binding_key as filter, Str sink, name, Str reply_sink, reply_name) ->
+      Util.with_mutex0 info.mtx
+	(fun () ->
+	  ignore (Subscription.create info.subscriptions filter sink name reply_sink reply_name))
+  | Message.Unsubscribe (Str token) ->
+      unsubscribe info token
+  | m ->
+      Util.message_not_understood classname m
+
+let factory arg =
+  match arg with
+  | (Arr [Str name]) ->
+      let info = {
+	name = name;
+	subscriptions = Subscription.new_set ();
+	mtx = Mutex.create ();
+      } in
+      replace_ok (Node.make_idempotent_named classname name (route_message info)) (Str name)
+  | _ ->
+      Problem (Str "bad-arg")
+
+let init () =
+  Factory.register_class classname factory

ocamlmsg.ml

@@ -13,6 +13,7 @@ let _ =
   Uuid.init ();
   Factory.init ();
   Queuenode.init ();
+  Fanoutnode.init ();
   Directnode.init ();
   hook_log ();
   Amqp_relay.init ();