%%%----------------------------------------------------------------------
%%% File : ejabberd_hooks.erl
%%% Author : Alexey Shchepin <alexey@sevcom.net>
%%% Purpose : Manage hooks
%%% Created : 8 Aug 2004 by Alexey Shchepin <alexey@sevcom.net>
%%% Id : $Id$
%%%----------------------------------------------------------------------
-module(ejabberd_hooks).
-author('alexey@sevcom.net').
-behaviour(gen_server).
%% External exports
-export([start_link/0,
add/4,
delete/4,
run/2,
run_fold/3,
add/5,
delete/5,
run/3,
run_fold/4]).
%% gen_server callbacks
-export([init/1,
handle_call/3,
handle_cast/2,
code_change/3,
handle_info/2,
terminate/2]).
-include("ejabberd.hrl").
-record(state, {}).
%%%----------------------------------------------------------------------
%%% API
%%%----------------------------------------------------------------------
start_link() ->
gen_server:start_link({local, ejabberd_hooks}, ejabberd_hooks, [], []).
add(Hook, Module, Function, Seq) ->
add(Hook, global, Module, Function, Seq).
add(Hook, Host, Module, Function, Seq) ->
gen_server:call(ejabberd_hooks, {add, Hook, Host, Module, Function, Seq}).
delete(Hook, Module, Function, Seq) ->
delete(Hook, global, Module, Function, Seq).
delete(Hook, Host, Module, Function, Seq) ->
gen_server:call(ejabberd_hooks, {delete, Hook, Host, Module, Function, Seq}).
run(Hook, Args) ->
run(Hook, global, Args).
run(Hook, Host, Args) ->
case ets:lookup(hooks, {Hook, Host}) of
[{_, Ls}] ->
run1(Ls, Hook, Args);
[] ->
ok
end.
run_fold(Hook, Val, Args) ->
run_fold(Hook, global, Val, Args).
run_fold(Hook, Host, Val, Args) ->
case ets:lookup(hooks, {Hook, Host}) of
[{_, Ls}] ->
run_fold1(Ls, Hook, Val, Args);
[] ->
Val
end.
%%%----------------------------------------------------------------------
%%% Callback functions from gen_server
%%%----------------------------------------------------------------------
%%----------------------------------------------------------------------
%% Func: init/1
%% Returns: {ok, State} |
%% {ok, State, Timeout} |
%% ignore |
%% {stop, Reason}
%%----------------------------------------------------------------------
init([]) ->
ets:new(hooks, [named_table]),
{ok, #state{}}.
%%----------------------------------------------------------------------
%% Func: handle_call/3
%% Returns: {reply, Reply, State} |
%% {reply, Reply, State, Timeout} |
%% {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, Reply, State} | (terminate/2 is called)
%% {stop, Reason, State} (terminate/2 is called)
%%----------------------------------------------------------------------
handle_call({add, Hook, Host, Module, Function, Seq}, From, State) ->
Reply = case ets:lookup(hooks, {Hook, Host}) of
[{_, Ls}] ->
El = {Seq, Module, Function},
case lists:member(El, Ls) of
true ->
ok;
false ->
NewLs = lists:merge(Ls, [El]),
ets:insert(hooks, {{Hook, Host}, NewLs}),
ok
end;
[] ->
NewLs = [{Seq, Module, Function}],
ets:insert(hooks, {{Hook, Host}, NewLs}),
ok
end,
{reply, Reply, State};
handle_call({delete, Hook, Host, Module, Function, Seq}, From, State) ->
Reply = case ets:lookup(hooks, {Hook, Host}) of
[{_, Ls}] ->
NewLs = lists:delete({Seq, Module, Function}, Ls),
ets:insert(hooks, {{Hook, Host}, NewLs}),
ok;
[] ->
ok
end,
{reply, Reply, State};
handle_call(Request, From, State) ->
Reply = ok,
{reply, Reply, State}.
%%----------------------------------------------------------------------
%% Func: handle_cast/2
%% Returns: {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, State} (terminate/2 is called)
%%----------------------------------------------------------------------
handle_cast(Msg, State) ->
{noreply, State}.
%%----------------------------------------------------------------------
%% Func: handle_info/2
%% Returns: {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, State} (terminate/2 is called)
%%----------------------------------------------------------------------
handle_info(Info, State) ->
{noreply, State}.
%%----------------------------------------------------------------------
%% Func: terminate/2
%% Purpose: Shutdown the server
%% Returns: any (ignored by gen_server)
%%----------------------------------------------------------------------
terminate(Reason, State) ->
ok.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%%----------------------------------------------------------------------
%%% Internal functions
%%%----------------------------------------------------------------------
run1([], Hook, Args) ->
ok;
run1([{_Seq, Module, Function} | Ls], Hook, Args) ->
case catch apply(Module, Function, Args) of
{'EXIT', Reason} ->
?ERROR_MSG("~p~nrunning hook: ~p",
[Reason, {Hook, Args}]),
run1(Ls, Hook, Args);
stop ->
ok;
_ ->
run1(Ls, Hook, Args)
end.
run_fold1([], Hook, Val, Args) ->
Val;
run_fold1([{_Seq, Module, Function} | Ls], Hook, Val, Args) ->
case catch apply(Module, Function, [Val | Args]) of
{'EXIT', Reason} ->
?ERROR_MSG("~p~nrunning hook: ~p",
[Reason, {Hook, Args}]),
run_fold1(Ls, Hook, Val, Args);
stop ->
stopped;
{stop, NewVal} ->
NewVal;
NewVal ->
run_fold1(Ls, Hook, NewVal, Args)
end.
