-module(active_echo_protocol).
-behaviour(ranch_protocol).
-export([start_link/4]).
-export([init/4]).
start_link(ListenerPid, Socket, Transport, Opts) ->
Pid = spawn_link(?MODULE, init, [ListenerPid, Socket, Transport, Opts]),
{ok, Pid}.
init(ListenerPid, Socket, Transport, _Opts = []) ->
ok = ranch:accept_ack(ListenerPid),
loop(Socket, Transport).
loop(Socket, Transport) ->
{OK, Closed, Error} = Transport:messages(),
Transport:setopts(Socket, [{active, once}]),
receive
{OK, Socket, Data} ->
Transport:send(Socket, Data),
loop(Socket, Transport);
{Closed, Socket} ->
ok;
{Error, Socket, _} ->
ok = Transport:close(Socket)
end.
