module websocket import net import x.openssl import log import time import rand // Server represents a websocket server connection pub struct Server { mut: logger &log.Log // logger used to log ls &net.TcpListener // listener used to get incoming connection to socket accept_client_callbacks []AcceptClientFn // accept client callback functions message_callbacks []MessageEventHandler // new message callback functions close_callbacks []CloseEventHandler // close message callback functions pub: port int // port used as listen to incoming connections is_ssl bool // true if secure connection (not supported yet on server) pub mut: clients map[string]&ServerClient // clients connected to this server ping_interval int = 30 // interval for sending ping to clients (seconds) state State // current state of connection } // ServerClient represents a connected client struct ServerClient { pub: resource_name string // resource that the client access client_key string // unique key of client pub mut: server &Server client &Client } // new_server instance a new websocket server on provided port and route pub fn new_server(port int, route string) &Server { return &Server{ ls: 0 port: port logger: &log.Log{ level: .info } state: .closed } } // set_ping_interval sets the interval that the server will send ping messages to clients pub fn (mut s Server) set_ping_interval(seconds int) { s.ping_interval = seconds } // listen start listen and process to incoming connections from websocket clients pub fn (mut s Server) listen() ? { s.logger.info('websocket server: start listen on port $s.port') s.ls = net.listen_tcp(s.port) ? s.set_state(.open) go s.handle_ping() for { mut c := s.accept_new_client() or { continue } go s.serve_client(mut c) } s.logger.info('websocket server: end listen on port $s.port') } // Close closes server (not implemented yet) fn (mut s Server) close() { // TODO: implement close when moving to net from x.net } // handle_ping sends ping to all clients every set interval fn (mut s Server) handle_ping() { mut clients_to_remove := []string{} for s.state == .open { time.sleep(s.ping_interval) for _, cli in s.clients { mut c := cli if c.client.state == .open { c.client.ping() or { s.logger.debug('server-> error sending ping to client') c.client.close(1002, 'Closing connection: ping send error') or { // we want to continue even if error continue } clients_to_remove << c.client.id } if (time.now().unix - c.client.last_pong_ut) > s.ping_interval * 2 { clients_to_remove << c.client.id c.client.close(1000, 'no pong received') or { continue } } } } // TODO: replace for with s.clients.delete_all(clients_to_remove) if (https://github.com/vlang/v/pull/6020) merges for client in clients_to_remove { lock { s.clients.delete(client) } } clients_to_remove.clear() } } // serve_client accepts incoming connection and sets up the callbacks fn (mut s Server) serve_client(mut c Client) ? { c.logger.debug('server-> Start serve client ($c.id)') defer { c.logger.debug('server-> End serve client ($c.id)') } mut handshake_response, mut server_client := s.handle_server_handshake(mut c) ? accept := s.send_connect_event(mut server_client) ? if !accept { s.logger.debug('server-> client not accepted') c.shutdown_socket() ? return } // the client is accepted c.socket_write(handshake_response.bytes()) ? lock { s.clients[server_client.client.id] = server_client } s.setup_callbacks(mut server_client) c.listen() or { s.logger.error(err) return error(err) } } // setup_callbacks initialize all callback functions fn (mut s Server) setup_callbacks(mut sc ServerClient) { if s.message_callbacks.len > 0 { for cb in s.message_callbacks { if cb.is_ref { sc.client.on_message_ref(cb.handler2, cb.ref) } else { sc.client.on_message(cb.handler) } } } if s.close_callbacks.len > 0 { for cb in s.close_callbacks { if cb.is_ref { sc.client.on_close_ref(cb.handler2, cb.ref) } else { sc.client.on_close(cb.handler) } } } // set standard close so we can remove client if closed sc.client.on_close_ref(fn (mut c Client, code int, reason string, mut sc ServerClient) ? { c.logger.debug('server-> Delete client') lock { sc.server.clients.delete(sc.client.id) } }, sc) } // accept_new_client creates a new client instance for client that connects to the socket fn (mut s Server) accept_new_client() ?&Client { mut new_conn := s.ls.accept() ? c := &Client{ is_server: true conn: new_conn ssl_conn: openssl.new_ssl_conn() logger: s.logger state: .open last_pong_ut: time.now().unix id: rand.uuid_v4() } return c } // set_state sets current state in a thread safe way fn (mut s Server) set_state(state State) { lock { s.state = state } } // free manages manual free of memory for Server instance pub fn (mut s Server) free() { unsafe { s.clients.free() s.accept_client_callbacks.free() s.message_callbacks.free() s.close_callbacks.free() } }