helper method for not_found errors

There was enough repetition to make it worthwhile

Author: Matthias Radestock

src/rabbit_amqqueue.erl

@@ -201,9 +201,7 @@ with(Name, F, E) ->
 with(Name, F) ->
     with(Name, F, fun () -> {error, not_found} end).
 with_or_die(Name, F) ->
-    with(Name, F, fun () -> rabbit_misc:protocol_error(
-                              not_found, "no ~s", [rabbit_misc:rs(Name)])
-                  end).
+    with(Name, F, fun () -> rabbit_misc:not_found(Name) end).
 
 list(VHostPath) ->
     mnesia:dirty_match_object(

src/rabbit_channel.erl

@@ -579,8 +579,7 @@ handle_method(#'exchange.delete'{exchange = ExchangeNameBin,
     check_configure_permitted(ExchangeName, State),
     case rabbit_exchange:delete(ExchangeName, IfUnused) of
         {error, not_found} ->
-            rabbit_misc:protocol_error(
-              not_found, "no ~s", [rabbit_misc:rs(ExchangeName)]);
+            rabbit_misc:not_found(ExchangeName);
         {error, in_use} ->
             die_precondition_failed(
               "~s in use", [rabbit_misc:rs(ExchangeName)]);
@@ -746,11 +745,9 @@ binding_action(Fun, ExchangeNameBin, QueueNameBin, RoutingKey, Arguments,
     check_read_permitted(ExchangeName, State),
     case Fun(ExchangeName, QueueName, ActualRoutingKey, Arguments) of
         {error, exchange_not_found} ->
-            rabbit_misc:protocol_error(
-              not_found, "no ~s", [rabbit_misc:rs(ExchangeName)]);
+            rabbit_misc:not_found(ExchangeName);
         {error, queue_not_found} ->
-            rabbit_misc:protocol_error(
-              not_found, "no ~s", [rabbit_misc:rs(QueueName)]);
+            rabbit_misc:not_found(QueueName);
         {error, exchange_and_queue_not_found} ->
             rabbit_misc:protocol_error(
               not_found, "no ~s and no ~s", [rabbit_misc:rs(ExchangeName),

src/rabbit_exchange.erl

@@ -164,9 +164,7 @@ lookup(Name) ->
 lookup_or_die(Name) ->
     case lookup(Name) of
         {ok, X} -> X;
-        {error, not_found} ->
-            rabbit_misc:protocol_error(
-              not_found, "no ~s", [rabbit_misc:rs(Name)])
+        {error, not_found} -> rabbit_misc:not_found(Name)
     end.
 
 list(VHostPath) ->

src/rabbit_misc.erl

@@ -36,6 +36,7 @@
 
 -export([method_record_type/1, polite_pause/0, polite_pause/1]).
 -export([die/1, frame_error/2, protocol_error/3, protocol_error/4]).
+-export([not_found/1]).
 -export([get_config/1, get_config/2, set_config/2]).
 -export([dirty_read/1]).
 -export([r/3, r/2, rs/1]).
@@ -72,6 +73,7 @@
       (atom() | amqp_error(), string(), [any()]) -> no_return()).
 -spec(protocol_error/4 ::
       (atom() | amqp_error(), string(), [any()], atom()) -> no_return()).
+-spec(not_found/1 :: (r(atom())) -> no_return()).
 -spec(get_config/1 :: (atom()) -> {'ok', any()} | not_found()).
 -spec(get_config/2 :: (atom(), A) -> A).
 -spec(set_config/2 :: (atom(), any()) -> 'ok').
@@ -139,6 +141,8 @@ protocol_error(Error, Explanation, Params, Method) ->
     CompleteExplanation = lists:flatten(io_lib:format(Explanation, Params)),
     exit({amqp, Error, CompleteExplanation, Method}).
 
+not_found(R) -> protocol_error(not_found, "no ~s", [rs(R)]).
+
 get_config(Key) ->
     case dirty_read({rabbit_config, Key}) of
         {ok, {rabbit_config, Key, V}} -> {ok, V};