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mirror of https://github.com/processone/ejabberd.git synced 2024-12-04 16:40:36 +01:00
xmpp.chapril.org-ejabberd/src/ejabberd_hooks.erl
Evgeniy Khramtsov 06eb54fef8 * src/ejabberd_hooks.erl: fixed typo
SVN Revision: 1970
2009-03-06 10:03:29 +00:00

258 lines
8.2 KiB
Erlang

%%%----------------------------------------------------------------------
%%% File : ejabberd_hooks.erl
%%% Author : Alexey Shchepin <alexey@process-one.net>
%%% Purpose : Manage hooks
%%% Created : 8 Aug 2004 by Alexey Shchepin <alexey@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2009 ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License
%%% along with this program; if not, write to the Free Software
%%% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
%%% 02111-1307 USA
%%%
%%%----------------------------------------------------------------------
-module(ejabberd_hooks).
-author('alexey@process-one.net').
-behaviour(gen_server).
%% External exports
-export([start_link/0,
add/3,
add/4,
delete/3,
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, [], []).
%% @spec (Hook::atom(), Function::function(), Seq::integer()) -> ok
%% @doc See add/4.
add(Hook, Function, Seq) when is_function(Function) ->
add(Hook, global, undefined, Function, Seq).
add(Hook, Host, Function, Seq) when is_function(Function) ->
add(Hook, Host, undefined, Function, Seq);
%% @spec (Hook::atom(), Module::atom(), Function::atom(), Seq::integer()) -> ok
%% @doc Add a module and function to this hook.
%% The integer sequence is used to sort the calls: low number is called before high number.
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}).
%% @spec (Hook::atom(), Function::function(), Seq::integer()) -> ok
%% @doc See del/4.
delete(Hook, Function, Seq) when is_function(Function) ->
delete(Hook, global, undefined, Function, Seq).
delete(Hook, Host, Function, Seq) when is_function(Function) ->
delete(Hook, Host, undefined, Function, Seq);
%% @spec (Hook::atom(), Module::atom(), Function::atom(), Seq::integer()) -> ok
%% @doc Delete a module and function from this hook.
%% It is important to indicate exactly the same information than when the call was added.
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}).
%% @spec (Hook::atom(), Args) -> ok
%% @doc Run the calls of this hook in order, don't care about function results.
%% If a call returns stop, no more calls are performed.
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.
%% @spec (Hook::atom(), Val, Args) -> Val | stopped | NewVal
%% @doc Run the calls of this hook in order.
%% The arguments passed to the function are: [Val | Args].
%% The result of a call is used as Val for the next call.
%% If a call returns 'stop', no more calls are performed and 'stopped' is returned.
%% If a call returns {stopped, NewVal}, no more calls are performed and NewVal is returned.
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) ->
Res = if is_function(Function) ->
catch apply(Function, Args);
true ->
catch apply(Module, Function, Args)
end,
case Res 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) ->
Res = if is_function(Function) ->
catch apply(Function, [Val | Args]);
true ->
catch apply(Module, Function, [Val | Args])
end,
case Res 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.