optimise confirms for unroutable messages; don't do any unnecessary set/dict operations

1 files changed, 13 insertions, 12 deletions

diff --git a/src/rabbit_channel.erl b/src/rabbit_channel.erl
index 930e48e6..f4122e95 100644
--- a/src/rabbit_channel.erl
+++ b/src/rabbit_channel.erl
@@ -475,13 +475,14 @@ confirm([], _QPid, State) ->
     State;
 confirm(_MsgSeqNos, _QPid, State = #ch{confirm_enabled = false}) ->
     State;
-confirm(MsgSeqNos, undefined, State = #ch{unconfirmed = UC,
-                                          queues_for_msg = QFM}) ->
-    MsgSeqNos1 = [MSN || MSN <- MsgSeqNos, gb_sets:is_element(MSN, UC)],
-    MS = gb_sets:from_list(MsgSeqNos),
-    QFM1 = dict:filter(fun(M, _Q) -> not(gb_sets:is_element(M, MS)) end, QFM),
-    send_confirms(MsgSeqNos1, State#ch{unconfirmed = gb_sets:difference(UC, MS),
-                                       queues_for_msg = QFM1});
+confirm(MsgSeqNos, undefined, State) ->
+    %% This case is for confirms originating in the channel: it is
+    %% only triggered by unroutable messages marked mandatory or
+    %% immediate or messages routed to zero queues.  In this case, 1)
+    %% the unconfirmed set does not contain the message, and 2) the
+    %% message was not delivered to any queues, so queues_for_msg will
+    %% not have any relevant entries.
+    send_confirms(MsgSeqNos, State);
 confirm(MsgSeqNos, QPid, State) ->
     {DoneMessages, State1} =
         lists:foldl(
@@ -544,9 +545,7 @@ handle_method(#'basic.publish'{exchange    = ExchangeNameBin,
               false -> {undefined, State};
               true  -> SeqNo = State#ch.publish_seqno,
                        {SeqNo,
-                        State#ch{publish_seqno = SeqNo + 1,
-                                 unconfirmed =
-                                     gb_sets:add(SeqNo, State#ch.unconfirmed)}}
+                        State#ch{publish_seqno = SeqNo + 1}}
           end,
     Message = #basic_message{exchange_name = ExchangeName,
                              routing_key   = RoutingKey,
@@ -1227,10 +1226,12 @@ process_routing_result(routed,       [], MsgSeqNo,       _, State) ->
 process_routing_result(routed,        _, undefined,      _, State) ->
     State;
 process_routing_result(routed,    QPids, MsgSeqNo,       _,
-                       State = #ch{queues_for_msg = QFM}) ->
+                       State = #ch{queues_for_msg = QFM,
+                                   unconfirmed    = UC}) ->
     QFM1 = dict:store(MsgSeqNo, sets:from_list(QPids), QFM),
     [maybe_monitor(QPid) || QPid <- QPids],
-    State#ch{queues_for_msg = QFM1}.
+    State#ch{queues_for_msg = QFM1,
+             unconfirmed = gb_sets:add(MsgSeqNo, UC)}.
 
 lock_message(true, MsgStruct, State = #ch{unacked_message_q = UAMQ}) ->
     State#ch{unacked_message_q = queue:in(MsgStruct, UAMQ)};