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-module(server).
-export([server/0, server/2, worker/2, create_workers/2, acceptor/2, listener/1, manager/1, broadcast/2, broadcast/3, handle_data/3]).
server() ->
server(1235, 10).
server(Port, NumWorkers) ->
ets:new(client_table, [named_table, public, {read_concurrency, true}]),
ets:insert(client_table, {counter, 0}),
ets:insert(client_table, {server, "Server"}),
{ok, ServerSock} = gen_tcp:listen(Port, [list]),
spawn(?MODULE, create_workers, [NumWorkers, self()]),
supervisor(ServerSock, []).
create_workers(0, _) -> ok;
create_workers(Num, Supervisor) ->
Supervisor ! worker_new,
create_workers(Num - 1, Supervisor).
supervisor(ServerSock, Pids) ->
receive
worker_new ->
{NewPid, _} = spawn_monitor(?MODULE, worker, [ServerSock, Pids]),
io:format("Creating new worker ~p\n", [NewPid]),
message_all(Pids, {ping, NewPid}),
supervisor(ServerSock, [NewPid | Pids]);
{'DOWN', _, process, From, Reason} ->
io:format("Worker ~p exited due to ~p\n", [From, Reason]),
self() ! create,
message_all(lists:delete(From, Pids), {close, From}),
supervisor(ServerSock, lists:delete(From, Pids));
{announce, Data} ->
[Pid|_] = Pids,
Pid ! {broadcast, "Server", ok, Data},
supervisor(ServerSock, Pids)
end.
message_all([Pid|Pids], Data) ->
Pid ! Data,
message_all(Pids, Data);
message_all([], _) -> ok.
worker(ServerSock, Pids) ->
process_flag(trap_exit, false),
ListenerPid = spawn_link(?MODULE, listener, [self()]),
spawn_link(?MODULE, acceptor, [ListenerPid, ServerSock]),
manager(Pids).
manager(Socks) ->
receive
{ping, Sock} ->
manager([Sock | Socks]);
{close, Sock} ->
manager(lists:delete(Sock, Socks));
{repeat, Data} ->
broadcast(Socks, Data, norepeat),
manager(Socks);
{broadcast, FromIden, FromSock, Data} ->
NewData = FromIden ++ ": " ++ Data,
broadcast(lists:delete(FromSock, Socks), NewData),
manager(Socks);
{pm, FromIden, ToSock, Data} ->
NewData = "(pm) " ++ FromIden ++ ": " ++ Data,
broadcast([ToSock], NewData),
manager(Socks)
end.
listener(ManagerPid) ->
receive
{tcp, Sock, Data} ->
spawn(?MODULE, handle_data, [ManagerPid, Sock, Data]),
listener(ManagerPid);
{tcp_opened, Sock} ->
ManagerPid ! {ping, Sock},
client_add(Sock),
listener(ManagerPid);
{tcp_closed, Sock} ->
ManagerPid ! {close, Sock},
client_del(Sock),
listener(ManagerPid)
end.
acceptor(ListenerPid, ServerSock) ->
case gen_tcp:accept(ServerSock) of
{ok, Sock} ->
ok = gen_tcp:controlling_process(Sock, ListenerPid),
ListenerPid ! {tcp_opened, Sock},
acceptor(ListenerPid, ServerSock)
end.
handle_data(ManagerPid, From, Data) ->
case catch parse_data(ManagerPid, From, Data) of
ok -> ok;
_ ->
ManagerPid ! {pm, "Server", From, "ERR: Transaction Failed\n"}
end.
parse_data(ManagerPid, From, Data) ->
case string:tokens(Data, " ") of
["/pm" | [ToIden | _]] ->
NewData = string:slice(Data, string:length(ToIden) + 5),
ManagerPid ! {pm, client_iden(From), client_sock(ToIden), NewData};
["\n"] -> ok;
_ ->
ManagerPid ! {broadcast, client_iden(From), From, Data}
end, ok.
broadcast(Socks, Data) ->
broadcast(Socks, Data, ok).
broadcast([Pid|Socks], Data, norepeat) when is_pid(Pid) ->
broadcast(Socks, Data, norepeat);
broadcast([Pid|Socks], Data, Opt) when is_pid(Pid) ->
Pid ! {repeat, Data},
broadcast(Socks, Data, Opt);
broadcast([Sock|Socks], Data, Opt) ->
gen_tcp:send(Sock, Data),
broadcast(Socks, Data, Opt);
broadcast([], _, _) -> ok.
client_add(Sock) ->
[{_, Count}|_] = ets:lookup(client_table, counter),
Iden = "Anon"++integer_to_list(Count),
ets:insert(client_table, {Iden, Sock}),
ets:insert(client_table, {Sock, Iden}),
ets:update_counter(client_table, counter, 1).
client_del(Sock) ->
[{_, Iden}|_] = ets:lookup(client_table, Sock),
ets:delete(client_table, Sock),
ets:delete(client_table, Iden).
client_iden(Sock) ->
[{_, Iden}|_] = ets:lookup(client_table, Sock),
Iden.
client_sock(Iden) ->
[{_, Sock}|_] = ets:lookup(client_table, Iden),
Sock.
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