turn websocket demo into a simple chat client
Project: http://git-wip-us.apache.org/repos/asf/couchdb-mochiweb/repo Commit: http://git-wip-us.apache.org/repos/asf/couchdb-mochiweb/commit/d253ce86 Tree: http://git-wip-us.apache.org/repos/asf/couchdb-mochiweb/tree/d253ce86 Diff: http://git-wip-us.apache.org/repos/asf/couchdb-mochiweb/diff/d253ce86 Branch: refs/heads/1843-feature-bigcouch Commit: d253ce86c16b92b499e7155711ff80ce89072c69 Parents: 49eaab9 Author: Bob Ippolito <[email protected]> Authored: Thu Dec 26 13:07:04 2013 -0800 Committer: Bob Ippolito <[email protected]> Committed: Thu Dec 26 13:07:04 2013 -0800 ---------------------------------------------------------------------- examples/websocket/websocket.erl | 84 ++++++++++++++++++++++++++++------- 1 file changed, 69 insertions(+), 15 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/couchdb-mochiweb/blob/d253ce86/examples/websocket/websocket.erl ---------------------------------------------------------------------- diff --git a/examples/websocket/websocket.erl b/examples/websocket/websocket.erl index 4049941..4a782d8 100644 --- a/examples/websocket/websocket.erl +++ b/examples/websocket/websocket.erl @@ -24,7 +24,8 @@ %% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN %% THE SOFTWARE. --export([start/0, start_link/0, ws_loop/3, loop/1]). +-export([start/0, start_link/0, ws_loop/3, loop/2]). +-export([broadcast_server/1]). %% %% Mochiweb websocket example @@ -52,42 +53,95 @@ %% [7]: Print payload received from client and send it back %% [8]: Message handling function must return new state value start() -> - application:start(sasl), - start_link(), - erlang:hibernate(?MODULE, start, []). + spawn( + fun () -> + application:start(sasl), + start_link(), + receive + stop -> ok + end + end). start_link() -> %% [1] io:format("Listening at http://127.0.0.1:8080/~n";), + Broadcaster = spawn_link(?MODULE, broadcast_server, [dict:new()]), mochiweb_http:start_link([ {name, client_access}, - {loop, fun ?MODULE:loop/1}, + {loop, {?MODULE, loop, [Broadcaster]}}, {port, 8080} ]). -ws_loop(Payload, State, ReplyChannel) -> +ws_loop(Payload, Broadcaster, _ReplyChannel) -> %% [6] %% [7] io:format("Received data: ~p~n", [Payload]), Received = list_to_binary(Payload), - ReplyChannel(<<"Received ", Received/binary>>), + Broadcaster ! {broadcast, self(), Received}, %% [8] - State. + Broadcaster. -loop(Req) -> +loop(Req, Broadcaster) -> H = mochiweb_request:get_header_value("Upgrade", Req), - loop(Req, H =/= undefined andalso string:to_lower(H) =:= "websocket"). + loop(Req, + Broadcaster, + H =/= undefined andalso string:to_lower(H) =:= "websocket"). -loop(Req, false) -> +loop(Req, _Broadcaster, false) -> mochiweb_request:serve_file("index.html", "./", Req); -loop(Req, true) -> +loop(Req, Broadcaster, true) -> {ReentryWs, ReplyChannel} = mochiweb_websocket:upgrade_connection( Req, fun ?MODULE:ws_loop/3), %% [3] - ReplyChannel(<<"Hello">>), + Broadcaster ! {register, self(), ReplyChannel}, %% [4] - InitialState = [], %% [5] - ReentryWs(InitialState). + ReentryWs(Broadcaster). + + +%% This server keeps track of connected pids +broadcast_server(Pids) -> + Pids1 = receive + {register, Pid, Channel} -> + broadcast_register(Pid, Channel, Pids); + {broadcast, Pid, Message} -> + broadcast_sendall(Pid, Message, Pids); + {'DOWN', MRef, process, Pid, _Reason} -> + broadcast_down(Pid, MRef, Pids); + Msg -> + io:format("Unknown message: ~p~n", [Msg]) + end, + erlang:hibernate(?MODULE, broadcast_server, [Pids1]). + +broadcast_register(Pid, Channel, Pids) -> + MRef = erlang:monitor(process, Pid), + broadcast_sendall( + Pid, "connected", dict:store(Pid, {Channel, MRef}, Pids)). + +broadcast_down(Pid, MRef, Pids) -> + Pids1 = case dict:find(Pid, Pids) of + {ok, {_, MRef}} -> + dict:erase(Pid, Pids); + _ -> + Pids + end, + broadcast_sendall(Pid, "disconnected", Pids1). + +broadcast_sendall(Pid, Msg, Pids) -> + M = iolist_to_binary([pid_to_list(Pid), ": ", Msg]), + dict:fold( + fun (K, {Reply, MRef}, Acc) -> + try + begin + Reply(M), + dict:store(K, {Reply, MRef}, Acc) + end + catch + _:_ -> + Acc + end + end, + dict:new(), + Pids).
