Extract some header-munging functions into rabbit_basic (not sure that's the best place, but rabbit_misc is already overflowing and rabbit_headers did not seem justified).

2 files changed, 40 insertions, 33 deletions

diff --git a/src/rabbit_amqqueue_process.erl b/src/rabbit_amqqueue_process.erl
index 951a5008bf..b92a0d3ccb 100644
--- a/src/rabbit_amqqueue_process.erl
+++ b/src/rabbit_amqqueue_process.erl
@@ -896,48 +896,27 @@ make_dead_letter_msg(DLX, Reason,
                                           exchange_name = Exchange,
                                           routing_keys  = RoutingKeys},
                      State = #q{dlx_routing_key = DlxRoutingKey}) ->
-    Content1 = #content{
-      properties = Props = #'P_basic'{headers = Headers}} =
-        rabbit_binary_parser:ensure_content_decoded(Content),
-
+    Headers = rabbit_basic:extract_headers(Content),
     #resource{name = QName} = qname(State),
-
     %% The first routing key is the one specified in the
     %% basic.publish; all others are CC or BCC keys.
     RoutingKeys1 = [hd(RoutingKeys) | rabbit_basic:header_routes(Headers)],
-    DeathTable = {table, [{<<"reason">>, longstr,
-                           list_to_binary(atom_to_list(Reason))},
-                          {<<"queue">>, longstr, QName},
-                          {<<"time">>, timestamp,
-                           rabbit_misc:now_ms() div 1000},
-                          {<<"exchange">>, longstr, Exchange#resource.name},
-                          {<<"routing-keys">>, array,
-                           [{longstr, Key} || Key <- RoutingKeys1]}]},
-    Headers1 =
-        case Headers of
-            undefined ->
-                [{<<"x-death">>, array, [DeathTable]}];
-            _ ->
-                case rabbit_misc:table_lookup(Headers, <<"x-death">>) of
-                    {array, Prior} ->
-                        rabbit_misc:set_table_value(
-                          Headers, <<"x-death">>, array,
-                          [DeathTable | Prior]);
-                    _ ->
-                        [{<<"x-death">>, array, [DeathTable]} | Headers]
-                end
-        end,
+    Info = [{<<"reason">>, longstr, list_to_binary(atom_to_list(Reason))},
+            {<<"queue">>, longstr, QName},
+            {<<"time">>, timestamp, rabbit_misc:now_ms() div 1000},
+            {<<"exchange">>, longstr, Exchange#resource.name},
+            {<<"routing-keys">>, array,
+             [{longstr, Key} || Key <- RoutingKeys1]}],
+    Headers1 = rabbit_basic:append_table_header(<<"x-death">>, Info, Headers),
     {DeathRoutingKeys, Headers2} =
         case DlxRoutingKey of
             undefined -> {RoutingKeys, Headers1};
             _         -> {[DlxRoutingKey],
                           lists:keydelete(<<"CC">>, 1, Headers1)}
         end,
-    Content2 =
-        rabbit_binary_generator:clear_encoded_content(
-          Content1#content{properties = Props#'P_basic'{headers = Headers2}}),
+    Content1 = rabbit_basic:replace_headers(Headers2, Content),
     Msg#basic_message{exchange_name = DLX, id = rabbit_guid:gen(),
-                      routing_keys = DeathRoutingKeys, content = Content2}.
+                      routing_keys = DeathRoutingKeys, content = Content1}.
 
 
 now_micros() -> timer:now_diff(now(), {0,0,0}).
diff --git a/src/rabbit_basic.erl b/src/rabbit_basic.erl
index 8fbb39832a..a7b13511fa 100644
--- a/src/rabbit_basic.erl
+++ b/src/rabbit_basic.erl
@@ -19,8 +19,8 @@
 -include("rabbit_framing.hrl").
 
 -export([publish/4, publish/6, publish/1,
-         message/3, message/4, properties/1, delivery/4,
-         header_routes/1]).
+         message/3, message/4, properties/1, append_table_header/3,
+         extract_headers/1, replace_headers/2, delivery/4, header_routes/1]).
 -export([build_content/2, from_content/1]).
 
 %%----------------------------------------------------------------------------
@@ -32,6 +32,7 @@
 -type(publish_result() ::
         ({ok, rabbit_amqqueue:routing_result(), [pid()]}
          | rabbit_types:error('not_found'))).
+-type(headers() :: rabbit_framing:amqp_table() | 'undefined').
 
 -type(exchange_input() :: (rabbit_types:exchange() | rabbit_exchange:name())).
 -type(body_input() :: (binary() | [binary()])).
@@ -56,6 +57,15 @@
                         rabbit_types:ok_or_error2(rabbit_types:message(), any())).
 -spec(properties/1 ::
         (properties_input()) -> rabbit_framing:amqp_property_record()).
+
+-spec(append_table_header/3 ::
+        (binary(), rabbit_framing:amqp_table(), headers()) -> headers()).
+
+-spec(extract_headers/1 :: (rabbit_types:content()) -> headers()).
+
+-spec(replace_headers/2 :: (headers(), rabbit_types:content())
+                           -> rabbit_types:content()).
+
 -spec(header_routes/1 ::
         (undefined | rabbit_framing:amqp_table()) ->
                               [string()] | rabbit_types:error(any())).
@@ -170,6 +180,24 @@ properties(P) when is_list(P) ->
                         end
                 end, #'P_basic'{}, P).
 
+append_table_header(Name, Info, undefined) ->
+    append_table_header(Name, Info, []);
+append_table_header(Name, Info, Headers) ->
+    Prior = case rabbit_misc:table_lookup(Headers, Name) of
+                undefined          -> [];
+                {array, Existing}  -> Existing
+            end,
+    rabbit_misc:set_table_value(Headers, Name, array, [{table, Info} | Prior]).
+
+extract_headers(Content) ->
+    #content{properties = #'P_basic'{headers = Headers}} =
+        rabbit_binary_parser:ensure_content_decoded(Content),
+    Headers.
+
+replace_headers(Headers, Content = #content{properties = Props}) ->
+    rabbit_binary_generator:clear_encoded_content(
+      Content#content{properties = Props#'P_basic'{headers = Headers}}).
+
 indexof(L, Element) -> indexof(L, Element, 1).
 
 indexof([], _Element, _N)              -> 0;