Changed hook function to be a {M,F,A} set instead

Author: Paul Jones

src/rabbit_hooks.erl

@@ -38,10 +38,8 @@
 
 -ifdef(use_specs).
 
--type(hookfun() :: fun((list()) -> 'ok')).
-
 -spec(start/0 :: () -> 'ok').
--spec(subscribe/3 :: (atom(), atom(), hookfun()) -> 'ok').
+-spec(subscribe/3 :: (atom(), atom(), {atom(), atom(), list()}) -> 'ok').
 -spec(unsubscribe/2 :: (atom(), atom()) -> 'ok').
 -spec(trigger/2 :: (atom(), list()) -> 'ok').
 
@@ -61,10 +59,10 @@ unsubscribe(Hook, HandlerName) ->
 
 trigger(Hook, Args) ->
     Hooks = ets:lookup(?TableName, Hook),
-    [case catch H(Args) of
+    [case catch apply(M, F, [Hook, Name, Args | A]) of
         {'EXIT', Reason} -> 
             rabbit_log:warning("Failed to execute handler ~p for hook ~p: ~p", 
                                [Name, Hook, Reason]);
         _ -> ok
-     end || {_, Name, H} <- Hooks],
+     end || {_, Name, {M, F, A}} <- Hooks],
     ok.

src/rabbit_tests.erl

@@ -33,6 +33,9 @@
 
 -export([all_tests/0, test_parsing/0]).
 
+%% Exported so the hook mechanism can call back
+-export([handle_hook/3, bad_handle_hook/3, extra_arg_hook/5]).
+
 -import(lists).
 
 -include("rabbit.hrl").
@@ -604,36 +607,32 @@ test_server_status() ->
 
 test_hooks() ->
     %% Firing of hooks calls all hooks in an isolated manner
-    rabbit_hooks:subscribe(test_hook, test, 
-                           fun(Args) -> 
-                               put(fired_testhook_handler, Args) 
-                           end),
-    rabbit_hooks:subscribe(test_hook, test2, 
-                           fun(Args) -> 
-                               put(fired_testhook_handler2, Args) 
-                           end),
-    rabbit_hooks:subscribe(test_hook2, test2,
-                           fun(Args) ->
-                               put(fired_testhook2_handler, Args)
-                           end),
+    rabbit_hooks:subscribe(test_hook, test, {rabbit_tests, handle_hook, []}),
+    rabbit_hooks:subscribe(test_hook, test2, {rabbit_tests, handle_hook, []}),
+    rabbit_hooks:subscribe(test_hook2, test2, {rabbit_tests, handle_hook, []}),
     rabbit_hooks:trigger(test_hook, [arg1, arg2]),
-    [arg1, arg2] = get(fired_testhook_handler),
-    [arg1, arg2] = get(fired_testhook_handler2),
-    undefined = get(fired_testhook2_handler),
+    [arg1, arg2] = get(test_hook_test_fired),
+    [arg1, arg2] = get(test_hook_test2_fired),
+    undefined = get(test_hook2_test2_fired),
 
     %% Hook Deletion works
-    put(fired_testhook_handler, undefined),
-    put(fired_testhook_handler2, undefined),
+    put(test_hook_test_fired, undefined),
+    put(test_hook_test2_fired, undefined),
     rabbit_hooks:unsubscribe(test_hook, test),
     rabbit_hooks:trigger(test_hook, [arg3, arg4]),
-    undefined = get(fired_testhook_handler),
-    [arg3, arg4] = get(fired_testhook_handler2),
-    undefined = get(fired_testhook2_handler),
+    undefined = get(test_hook_test_fired),
+    [arg3, arg4] = get(test_hook_test2_fired),
+    undefined = get(test_hook2_test2_fired),
 
     %% Catches exceptions from bad hooks
-    rabbit_hooks:subscribe(test_hook3, test, fun(Args) -> bad:bad() end),
+    rabbit_hooks:subscribe(test_hook3, test, {rabbit_tests, bad_handle_hook, []}),
     ok = rabbit_hooks:trigger(test_hook3, []),
 
+    %% Passing extra arguments to hooks
+    rabbit_hooks:subscribe(arg_hook, test, {rabbit_tests, extra_arg_hook, [1, 3]}),
+    rabbit_hooks:trigger(arg_hook, [arg1, arg2]),
+    {[arg1, arg2], 1, 3} = get(arg_hook_test_fired),
+
     passed.
 
 %---------------------------------------------------------------------
@@ -719,3 +718,11 @@ delete_log_handlers(Handlers) ->
     [[] = error_logger:delete_report_handler(Handler) ||
         Handler <- Handlers],
     ok.
+
+handle_hook(HookName, Handler, Args) ->
+    A = atom_to_list(HookName) ++ "_" ++ atom_to_list(Handler) ++ "_fired",
+    put(list_to_atom(A), Args).
+bad_handle_hook(_, _, _) ->
+    bad:bad().
+extra_arg_hook(Hookname, Handler, Args, Extra1, Extra2) ->
+    handle_hook(Hookname, Handler, {Args, Extra1, Extra2}).