Support optionally formatting the priority queue mailbox, and do so on the queue.

2 files changed, 27 insertions, 9 deletions

diff --git a/src/gen_server2.erl b/src/gen_server2.erl
index 43e0a8f5df..d1b24714be 100644
--- a/src/gen_server2.erl
+++ b/src/gen_server2.erl
@@ -1161,17 +1161,22 @@ format_status(Opt, StatusData) ->
               end,
     Header = lists:concat(["Status for generic server ", NameTag]),
     Log = sys:get_debug(log, Debug, []),
-    Specfic =
-        case erlang:function_exported(Mod, format_status, 2) of
-            true -> case catch Mod:format_status(Opt, [PDict, State]) of
-                        {'EXIT', _} -> [{data, [{"State", State}]}];
-                        Else        -> Else
-                    end;
-            _    -> [{data, [{"State", State}]}]
-        end,
+    Specfic = callback_format_status(Opt, Mod, format_status, [PDict, State],
+                                     [{data, [{"State", State}]}]),
+    Messages = callback_format_status(Opt, Mod, format_priority_mailbox, Queue,
+                                      priority_queue:to_list(Queue)),
     [{header, Header},
      {data, [{"Status", SysState},
              {"Parent", Parent},
              {"Logged events", Log},
-             {"Queued messages", priority_queue:to_list(Queue)}]} |
+             {"Queued messages", Messages}]} |
      Specfic].
+
+callback_format_status(Opt, Mod, FunName, Args, Default) ->
+    case erlang:function_exported(Mod, FunName, 2) of
+        true -> case catch Mod:FunName(Opt, Args) of
+                    {'EXIT', _} -> Default;
+                    Else        -> Else
+                end;
+        _    -> Default
+    end.
diff --git a/src/rabbit_amqqueue_process.erl b/src/rabbit_amqqueue_process.erl
index fcd6cc24e2..60c1135e01 100644
--- a/src/rabbit_amqqueue_process.erl
+++ b/src/rabbit_amqqueue_process.erl
@@ -35,6 +35,8 @@
 
 -export([init_with_backing_queue_state/7]).
 
+-export([format_priority_mailbox/2]).
+
 %% Queue's state
 -record(q, {q,
             exclusive_consumer,
@@ -1162,3 +1164,14 @@ handle_pre_hibernate(State = #q{backing_queue = BQ,
     State1 = State#q{stats_timer = rabbit_event:stop_stats_timer(StatsTimer),
                      backing_queue_state = BQS3},
     {hibernate, stop_rate_timer(State1)}.
+
+format_priority_mailbox(_Opt, Mailbox) ->
+    Len = priority_queue:len(Mailbox),
+    case Len > 100 of
+        false -> {Len, priority_queue:to_list(Mailbox)};
+        true  -> {Len, {dict:to_list(
+                          lists:foldl(
+                            fun ({P, _V}, Counts) ->
+                                    dict:update_counter(P, 1, Counts)
+                            end, dict:new(), priority_queue:to_list(Mailbox)))}}
+    end.