store less in the slave's msg_id_status

There is no need to track the ChPid of 'published' and 'confirmed'.

Also: neater conversion of msg_id_status on promotion.

1 files changed, 16 insertions, 20 deletions

diff --git a/src/rabbit_mirror_queue_slave.erl b/src/rabbit_mirror_queue_slave.erl
index 931a7f90..0530fa7f 100644
--- a/src/rabbit_mirror_queue_slave.erl
+++ b/src/rabbit_mirror_queue_slave.erl
@@ -406,16 +406,16 @@ confirm_messages(MsgIds, State = #state { msg_id_status = MS }) ->
                           %% If it needed confirming, it'll have
                           %% already been done.
                           Acc;
-                      {ok, {published, ChPid}} ->
+                      {ok, published} ->
                           %% Still not seen it from the channel, just
                           %% record that it's been confirmed.
-                          {CMsN, dict:store(MsgId, {confirmed, ChPid}, MSN)};
+                          {CMsN, dict:store(MsgId, confirmed, MSN)};
                       {ok, {published, ChPid, MsgSeqNo}} ->
                           %% Seen from both GM and Channel. Can now
                           %% confirm.
                           {rabbit_misc:gb_trees_cons(ChPid, MsgSeqNo, CMsN),
                            dict:erase(MsgId, MSN)};
-                      {ok, {confirmed, _ChPid}} ->
+                      {ok, confirmed} ->
                           %% It's already been confirmed. This is
                           %% probably it's been both sync'd to disk
                           %% and then delivered and ack'd before we've
@@ -482,18 +482,18 @@ promote_me(From, #state { q                   = Q = #amqqueue { name = QName },
     %%
     %% MS contains the following three entry types:
     %%
-    %% a) {published, ChPid}:
+    %% a) published:
     %%   published via gm only; pending arrival of publication from
     %%   channel, maybe pending confirm.
     %%
     %% b) {published, ChPid, MsgSeqNo}:
     %%   published via gm and channel; pending confirm.
     %%
-    %% c) {confirmed, ChPid}:
+    %% c) confirmed:
     %%   published via gm only, and confirmed; pending publication
     %%   from channel.
     %%
-    %% d) discarded
+    %% d) discarded:
     %%   seen via gm only as discarded. Pending publication from
     %%   channel
     %%
@@ -511,22 +511,18 @@ promote_me(From, #state { q                   = Q = #amqqueue { name = QName },
     %% this does not affect MS, nor which bits go through to SS in
     %% Master, or MTC in queue_process.
 
-    MSList = dict:to_list(MS),
-    SS = dict:from_list(
-           [E || E = {_MsgId, discarded} <- MSList] ++
-               [{MsgId, Status}
-                || {MsgId, {Status, _ChPid}} <- MSList,
-                   Status =:= published orelse Status =:= confirmed]),
+    St = [published, confirmed, discarded],
+    SS = dict:filter(fun (_MsgId, Status) -> lists:member(Status, St) end, MS),
     AckTags = [AckTag || {_MsgId, AckTag} <- dict:to_list(MA)],
 
     MasterState = rabbit_mirror_queue_master:promote_backing_queue_state(
                     CPid, BQ, BQS, GM, AckTags, SS, MPids),
 
-    MTC = lists:foldl(fun ({MsgId, {published, ChPid, MsgSeqNo}}, MTC0) ->
-                              gb_trees:insert(MsgId, {ChPid, MsgSeqNo}, MTC0);
-                          (_, MTC0) ->
-                              MTC0
-                      end, gb_trees:empty(), MSList),
+    MTC = dict:fold(fun (MsgId, {published, ChPid, MsgSeqNo}, MTC0) ->
+                            gb_trees:insert(MsgId, {ChPid, MsgSeqNo}, MTC0);
+                        (_Msgid, _Status, MTC0) ->
+                            MTC0
+                    end, gb_trees:empty(), MS),
     Deliveries = [Delivery || {_ChPid, {PubQ, _PendCh}} <- dict:to_list(SQ),
                               Delivery <- queue:to_list(PubQ)],
     rabbit_amqqueue_process:init_with_backing_queue_state(
@@ -637,14 +633,14 @@ maybe_enqueue_message(
             MQ1 = queue:in(Delivery, MQ),
             SQ1 = dict:store(ChPid, {MQ1, PendingCh}, SQ),
             State1 #state { sender_queues = SQ1 };
-        {ok, {confirmed, ChPid}} ->
+        {ok, confirmed} ->
             %% BQ has confirmed it but we didn't know what the
             %% msg_seq_no was at the time. We do now!
             ok = rabbit_misc:confirm_to_sender(ChPid, [MsgSeqNo]),
             SQ1 = remove_from_pending_ch(MsgId, ChPid, SQ),
             State1 #state { msg_id_status = dict:erase(MsgId, MS),
                             sender_queues = SQ1 };
-        {ok, {published, ChPid}} ->
+        {ok, published} ->
             %% It was published to the BQ and we didn't know the
             %% msg_seq_no so couldn't confirm it at the time.
             {MS1, SQ1} =
@@ -703,7 +699,7 @@ process_instruction(
         case queue:out(MQ) of
             {empty, _MQ2} ->
                 {MQ, sets:add_element(MsgId, PendingCh),
-                 dict:store(MsgId, {published, ChPid}, MS)};
+                 dict:store(MsgId, published, MS)};
             {{value, Delivery = #delivery {
                        msg_seq_no = MsgSeqNo,
                        message    = #basic_message { id = MsgId } }}, MQ2} ->