%% Copyright (c) 2011-2012, Loïc Hoguin <[email protected]>
%%
%% Permission to use, copy, modify, and/or distribute this software for any
%% purpose with or without fee is hereby granted, provided that the above
%% copyright notice and this permission notice appear in all copies.
%%
%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
%% @doc Public API for managing listeners.
-module(ranch_listener).
-behaviour(gen_server).
%% API.
-export([start_link/3]).
-export([stop/1]).
-export([add_connection/2]).
-export([remove_connection/1]).
-export([get_port/1]).
-export([set_port/2]).
-export([get_max_connections/1]).
-export([set_max_connections/2]).
-export([get_protocol_options/1]).
-export([set_protocol_options/2]).
%% gen_server.
-export([init/1]).
-export([handle_call/3]).
-export([handle_cast/2]).
-export([handle_info/2]).
-export([terminate/2]).
-export([code_change/3]).
-record(state, {
ref :: any(),
max_conns = undefined :: ranch:max_conns(),
port = undefined :: undefined | inet:port_number(),
proto_opts = undefined :: any(),
rm_diff = 0 :: non_neg_integer()
}).
%% API.
%% @private
-spec start_link(any(), non_neg_integer(), any()) -> {ok, pid()}.
start_link(Ref, MaxConns, ProtoOpts) ->
gen_server:start_link(?MODULE, [Ref, MaxConns, ProtoOpts], []).
%% @private
-spec stop(pid()) -> stopped.
stop(ServerPid) ->
gen_server:call(ServerPid, stop).
%% @doc Add a connection to the listener's pool.
-spec add_connection(pid(), pid()) -> non_neg_integer().
add_connection(ServerPid, ConnPid) ->
ok = gen_server:cast(ServerPid, {add_connection, ConnPid}),
ranch_server:add_connection(ServerPid).
%% @doc Remove this process' connection from the pool.
%%
%% Useful if you have long-lived connections that aren't taking up
%% resources and shouldn't be counted in the limited number of running
%% connections.
-spec remove_connection(pid()) -> non_neg_integer().
remove_connection(ServerPid) ->
try
Count = ranch_server:remove_connection(ServerPid),
ok = gen_server:cast(ServerPid, remove_connection),
Count
catch
error:badarg -> % Max conns = infinity
0
end.
%% @doc Return the listener's port.
-spec get_port(pid()) -> {ok, inet:port_number()}.
get_port(ServerPid) ->
gen_server:call(ServerPid, get_port).
%% @private
-spec set_port(pid(), inet:port_number()) -> ok.
set_port(ServerPid, Port) ->
gen_server:cast(ServerPid, {set_port, Port}).
%% @doc Return the max number of connections allowed concurrently.
-spec get_max_connections(pid()) -> {ok, ranch:max_conns()}.
get_max_connections(ServerPid) ->
gen_server:call(ServerPid, get_max_connections).
%% @doc Set the max number of connections allowed concurrently.
-spec set_max_connections(pid(), ranch:max_conns()) -> ok.
set_max_connections(ServerPid, MaxConnections) ->
gen_server:call(ServerPid, {set_max_connections, MaxConnections}).
%% @doc Return the current protocol options.
-spec get_protocol_options(pid()) -> {ok, any()}.
get_protocol_options(ServerPid) ->
gen_server:call(ServerPid, get_protocol_options).
%% @doc Upgrade the protocol options.
-spec set_protocol_options(pid(), any()) -> ok.
set_protocol_options(ServerPid, ProtoOpts) ->
gen_server:call(ServerPid, {set_protocol_options, ProtoOpts}).
%% gen_server.
%% @private
init([Ref, infinity, ProtoOpts]) ->
ok = ranch_server:insert_listener(Ref, self()),
{ok, #state{ref=Ref, max_conns=infinity, proto_opts=ProtoOpts}};
init([Ref, MaxConns, ProtoOpts]) ->
ok = ranch_server:insert_listener(Ref, self()),
ranch_server:add_connections_counter(self()),
{ok, #state{ref=Ref, max_conns=MaxConns, proto_opts=ProtoOpts}}.
%% @private
handle_call(get_port, _From, State=#state{port=Port}) ->
{reply, {ok, Port}, State};
handle_call(get_max_connections, _From, State=#state{max_conns=MaxConns}) ->
{reply, {ok, MaxConns}, State};
handle_call({set_max_connections, MaxConnections}, _From,
State=#state{ref=Ref, max_conns=CurrMax, rm_diff=CurrDiff}) ->
RmDiff = case {MaxConnections, CurrMax} of
{infinity, _} -> % moving to infinity, delete connection key
ranch_server:remove_connections_counter(self()),
0;
{_, infinity} -> % moving away from infinity, create connection key
ranch_server:add_connections_counter(self()),
CurrDiff;
{_, _} -> % stay current
CurrDiff
end,
ranch_server:send_to_acceptors(Ref, {set_max_conns, MaxConnections}),
{reply, ok, State#state{max_conns=MaxConnections, rm_diff=RmDiff}};
handle_call(get_protocol_options, _From, State=#state{proto_opts=ProtoOpts}) ->
{reply, {ok, ProtoOpts}, State};
handle_call({set_protocol_options, ProtoOpts}, _From, State=#state{ref=Ref}) ->
ranch_server:send_to_acceptors(Ref, {set_opts, ProtoOpts}),
{reply, ok, State#state{proto_opts=ProtoOpts}};
handle_call(stop, _From, State) ->
{stop, normal, stopped, State};
handle_call(_, _From, State) ->
{reply, ignored, State}.
%% @private
handle_cast({add_connection, ConnPid}, State) ->
_ = erlang:monitor(process, ConnPid),
{noreply, State};
handle_cast(remove_connection, State=#state{max_conns=infinity}) ->
{noreply, State};
handle_cast(remove_connection, State=#state{rm_diff=RmDiff}) ->
{noreply, State#state{rm_diff=RmDiff + 1}};
handle_cast({set_port, Port}, State) ->
{noreply, State#state{port=Port}};
handle_cast(_Msg, State) ->
{noreply, State}.
%% @private
handle_info({'DOWN', _, process, _, _}, State=#state{rm_diff=0}) ->
_ = ranch_server:remove_connection(self()),
{noreply, State};
handle_info({'DOWN', _, process, _, _}, State=#state{rm_diff=RmDiff}) ->
{noreply, State#state{rm_diff=RmDiff - 1}};
handle_info(_Info, State) ->
{noreply, State}.
%% @private
terminate(_Reason, _State) ->
ok.
%% @private
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
