Delay generating the basic_message id (guid)

until we know if it is needed or not.

deps/rabbit/src/rabbit_basic.erl

@@ -10,7 +10,7 @@
 -include_lib("rabbit_common/include/rabbit_framing.hrl").
 
 -export([publish/4, publish/5, publish/1,
-         message/3, message/4, properties/1, prepend_table_header/3,
+         message/3, message_no_id/3, message/4, properties/1, prepend_table_header/3,
          extract_headers/1, extract_timestamp/1, map_headers/2, delivery/4,
          header_routes/1, parse_expiration/1, header/2, header/3]).
 -export([build_content/2, from_content/1, msg_size/1,
@@ -130,19 +130,17 @@ strip_header(#content{properties = Props = #'P_basic'{headers = Headers}}
         (rabbit_exchange:name(), rabbit_router:routing_key(),
          rabbit_types:decoded_content()) ->
             rabbit_types:ok_or_error2(rabbit_types:message(), any()).
+message(XName, RoutingKey, Content) ->
+    make_message(XName, RoutingKey, Content, rabbit_guid:gen()).
 
-message(XName, RoutingKey, #content{properties = Props} = DecodedContent) ->
-    try
-        {ok, #basic_message{
-           exchange_name = XName,
-           content       = strip_header(DecodedContent, ?DELETED_HEADER),
-           id            = rabbit_guid:gen(),
-           is_persistent = is_message_persistent(DecodedContent),
-           routing_keys  = [RoutingKey |
-                            header_routes(Props#'P_basic'.headers)]}}
-    catch
-        {error, _Reason} = Error -> Error
-    end.
+%% only used by channel to avoid unnecessarily generating a guid when
+%% queue types do not need them
+-spec message_no_id
+        (rabbit_exchange:name(), rabbit_router:routing_key(),
+         rabbit_types:decoded_content()) ->
+            rabbit_types:ok_or_error2(rabbit_types:message(), any()).
+ message_no_id(XName, RoutingKey, Content) ->
+    make_message(XName, RoutingKey, Content, <<>>).
 
 -spec message
         (rabbit_exchange:name(), rabbit_router:routing_key(), properties_input(),
@@ -352,3 +350,17 @@ header_key(A) ->
 
 binary_prefix_64(Bin, Len) ->
     binary:part(Bin, 0, min(byte_size(Bin), Len)).
+
+make_message(XName, RoutingKey, #content{properties = Props} = DecodedContent, Guid) ->
+    try
+        {ok, #basic_message{
+           exchange_name = XName,
+           content       = strip_header(DecodedContent, ?DELETED_HEADER),
+           id            = Guid,
+           is_persistent = is_message_persistent(DecodedContent),
+           routing_keys  = [RoutingKey |
+                            header_routes(Props#'P_basic'.headers)]}}
+    catch
+        {error, _Reason} = Error -> Error
+    end.
+

deps/rabbit/src/rabbit_channel.erl

@@ -1315,7 +1315,7 @@ handle_method(#'basic.publish'{exchange    = ExchangeNameBin,
                      SeqNo = State0#ch.publish_seqno,
                      {SeqNo, State0#ch{publish_seqno = SeqNo + 1}}
         end,
-    case rabbit_basic:message(ExchangeName, RoutingKey, DecodedContent) of
+    case rabbit_basic:message_no_id(ExchangeName, RoutingKey, DecodedContent) of
         {ok, Message} ->
             Delivery = rabbit_basic:delivery(
                          Mandatory, DoConfirm, Message, MsgSeqNo),

deps/rabbit/src/rabbit_classic_queue.erl

@@ -7,11 +7,12 @@
 -record(msg_status, {pending :: [pid()],
                      confirmed = [] :: [pid()]}).
 
--record(?MODULE, {pid :: undefined | pid(), %% the current master pid
-                  qref :: term(), %% TODO
-                  unconfirmed = #{} ::
-                  #{non_neg_integer() => #msg_status{}}}).
 -define(STATE, ?MODULE).
+-record(?STATE, {pid :: undefined | pid(), %% the current master pid
+                 qref :: term(), %% TODO
+                 unconfirmed = #{} ::
+                 #{non_neg_integer() => #msg_status{}}}).
+
 
 -opaque state() :: #?STATE{}.
 
@@ -300,9 +301,13 @@ settlement_action(Type, QRef, MsgSeqs, Acc) ->
     {[{amqqueue:amqqueue(), state()}], rabbit_queue_type:actions()}.
 deliver(Qs0, #delivery{flow = Flow,
                        msg_seq_no = MsgNo,
-                       message = #basic_message{exchange_name = _Ex},
-                       confirm = Confirm} = Delivery) ->
-    %% TODO: record master and slaves for confirm processing
+                       message = #basic_message{} = Msg0,
+                       confirm = Confirm} = Delivery0) ->
+    %% add guid to content here instead of in rabbit_basic:message/3,
+    %% as classic queues are the only ones that need it
+    Msg = Msg0#basic_message{id = rabbit_guid:gen()},
+    Delivery = Delivery0#delivery{message = Msg},
+
     {MPids, SPids, Qs, Actions} = qpids(Qs0, Confirm, MsgNo),
     QPids = MPids ++ SPids,
     case Flow of