rabbit_auth_cache behaviour

deps/rabbitmq_auth_backend_cache/README.md

@@ -59,7 +59,8 @@ You can configure TTL for cache items, by using `cache_ttl` configuration item,
                                     {cache_ttl, 5000}]}].
 
 You can also use a custom cache module to store cached requests. This module
-should be an erlang module implementing `rabbit_auth_cache` behaviour.
+should be an erlang module implementing `rabbit_auth_cache` behaviour and (optionally)
+define `start_link` function to start cache process.
 
 This repository contains three such modules:
 
@@ -70,6 +71,7 @@ This repository contains three such modules:
 
 To specify module for caching you should use `cache_module` configuration item and 
 specify start args with `cache_module_args`.
+Start args should be list of arguments passed to module `start_link` function
 
     [{rabbitmq_auth_backend_cache, [{cache_module, rabbit_auth_backend_ets_segmented},
                                     {cache_module_args, [10000]}]}].

deps/rabbitmq_auth_backend_cache/src/rabbit_auth_backend_cache_app.erl

@@ -33,6 +33,12 @@ stop(_State) ->
 init([]) ->
     {ok, AuthCache} = application:get_env(rabbitmq_auth_backend_cache,
                                           cache_module),
+
     {ok, AuthCacheArgs} = application:get_env(rabbitmq_auth_backend_cache, cache_module_args),
-    {ok, {{one_for_one,3,10},[{auth_cache, {AuthCache, start_link, AuthCacheArgs},
-                               permanent, 5000, worker, [AuthCache]}]}}.
+    ChildSpecs = case erlang:function_exported(AuthCache, start_link, 
+                                               length(AuthCacheArgs)) of
+        true  -> [{auth_cache, {AuthCache, start_link, AuthCacheArgs},
+                  permanent, 5000, worker, [AuthCache]}];
+        false -> []
+    end,
+    {ok, {{one_for_one,3,10}, ChildSpecs}}.

deps/rabbitmq_auth_backend_cache/src/rabbit_auth_cache.erl

@@ -0,0 +1,37 @@
+%% The contents of this file are subject to the Mozilla Public License
+%% Version 1.1 (the "License"); you may not use this file except in
+%% compliance with the License. You may obtain a copy of the License
+%% at http://www.mozilla.org/MPL/
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and
+%% limitations under the License.
+%%
+%% The Original Code is RabbitMQ.
+%%
+%% The Initial Developer of the Original Code is GoPivotal, Inc.
+%% Copyright (c) 2007-2016 Pivotal Software, Inc.  All rights reserved.
+%%
+
+-module(rabbit_auth_cache).
+
+-ifdef(use_specs).
+
+-callback get(term()) -> term().
+
+-callback put(term(), term(), integer()) -> ok.
+
+-callback delete(term()) -> ok.
+
+-else.
+
+-export([behaviour_info/1]).
+
+behaviour_info(callbacks) ->
+    [{get, 1}, {put, 3}, {delete, 1}];
+behaviour_info(_Other) ->
+    undefined.
+
+-endif.
+

deps/rabbitmq_auth_backend_cache/src/rabbit_auth_cache_dict.erl

@@ -19,6 +19,8 @@
 -compile({no_auto_import,[get/1]}).
 -compile({no_auto_import,[put/2]}).
 
+-behaviour(rabbit_auth_cache).
+
 -export([start_link/0,
          get/1, put/3, delete/1]).
 

deps/rabbitmq_auth_backend_cache/src/rabbit_auth_cache_ets.erl

@@ -18,7 +18,8 @@
 -behaviour(gen_server2).
 -compile({no_auto_import,[get/1]}).
 -compile({no_auto_import,[put/2]}).
--compile(export_all).
+
+-behaviour(rabbit_auth_cache).
 
 -export([start_link/0,
          get/1, put/3, delete/1]).

deps/rabbitmq_auth_backend_cache/src/rabbit_auth_cache_ets_segmented.erl

@@ -16,6 +16,7 @@
 
 -module(rabbit_auth_cache_ets_segmented).
 -behaviour(gen_server2).
+-behaviour(rabbit_auth_cache).
 
 -export([start_link/1,
          get/1, put/3, delete/1]).

deps/rabbitmq_auth_backend_cache/src/rabbit_auth_cache_ets_segmented_stateless.erl

@@ -16,6 +16,7 @@
 
 -module(rabbit_auth_cache_ets_segmented_stateless).
 -behaviour(gen_server2).
+-behaviour(rabbit_auth_cache).
 
 -export([start_link/1,
          get/1, put/3, delete/1]).