Changes from Version 1 of EchoServer

Author:

JJR (IP: 207.194.78.216)

Timestamp:

02/26/07 19:16:38 (17 years ago)

Comment:

New example

EchoServer

@@ +1 @@
+{{{
+#!d
+/**
+ * TCP echo server.
+ *
+ * When started it binds to free local port and listens
+ * for incoming connections.
+ *
+ * It uses several Tango features:
+ *  * threads;
+ *  * logging;
+ *  * containers;
+ *  * networking I/O;
+ *
+ * Contact:
+ * dawid.ciezarkiewicz@asn.pl
+ */
+
+import tango.io.Stdout;
+import tango.io.Buffer;
+
+import tango.core.Thread;
+
+import tango.net.ServerSocket;
+import tango.net.InternetAddress;
+import tango.net.Socket;
+import tango.net.SocketConduit;
+
+import tango.text.convert.Format;
+
+import tango.util.log.ConsoleAppender;
+import tango.util.log.Log;
+import tango.util.log.Logger;
+
+import tango.util.collection.LinkSeq;
+
+/**
+ * Each connection will have one instance of this.
+ */
+class ClientHandler {
+        private Logger logger;
+        private SocketConduit socket;
+        private void[] buf;
+        private static uint GlobalId = 0;
+        private uint id;
+
+
+        public this(SocketConduit socket) {
+                this.socket = socket;
+                id = GlobalId++;
+
+                logger = Log.getLogger("client.handler." ~ Formatter("{0}", id));
+                logger.info("creating");
+
+                socket.getSocket.blocking(false);
+                socket.setTimeout(0);
+
+                /* this should give funny effect */
+                buf = new byte[2];
+        }
+
+        public ~this() {
+                /* get new one, because members are not valid now */
+                auto logger = Log.getLogger("client.handler." ~ Formatter("{0}", id));
+                logger.info("resources disposed");
+        }
+
+
+        /**
+         * Will throw error on the end of connection.
+         */
+        public void call() {
+                /*
+                 * XXX:
+                 * SocketConduit.read() is broken for a moment
+                 * http://www.dsource.org/projects/tango/ticket/279
+                 * because of that - all this isn't quite as
+                 * it should be, but it works well.
+                 */
+                auto ammount = socket.getSocket.receive(buf);
+                if (ammount == -1) {
+                        /* nothing */
+                } else if ((ammount == IConduit.Eof || ammount == 0)) {
+                        logger.info("connection ended");
+                        throw new Exception("connection ended");
+                } else if (ammount > 0) {
+                        logger.trace("got " ~ Formatter("{0}", ammount) ~ " bytes");
+                        socket.write(buf[0..ammount]);
+                }
+
+        }
+
+}
+
+/**
+ * Manages client connections.
+ *
+ * It's a thread looping over list of clients
+ * calling ClientHandler.call() member
+ * and removing closed ones.
+ */
+class ClientManager {
+        private Thread thread;
+        private Logger logger;
+        LinkSeq!(ClientHandler) clients;
+
+        public this() {
+                clients = new LinkSeq!(ClientHandler);
+                logger = Log.getLogger("client.manager");
+
+                logger.info("creating thread");
+                thread = new Thread(&this.clientLoop);
+
+                logger.info("starting thread");
+                thread.start();
+        }
+
+        private void clientLoop() {
+                while (true) {
+                        synchronized (clients) {
+                                auto to_delete = new LinkSeq!(ClientHandler);
+
+                                foreach (client; clients) {
+                                        try {
+                                                client.call();
+                                        } catch (Exception e) {
+                                                to_delete.append(client);
+                                        }
+                                }
+
+                                foreach (client; to_delete) {
+                                        clients.remove(client);
+                                }
+                        }
+                        Thread.sleep(0.1);
+                }
+        }
+
+        public void spawn(SocketConduit sc) {
+                synchronized (clients) {
+                        clients.append(new ClientHandler(sc));
+                }
+        }
+}
+
+/**
+ * Thread that loops accepting incoming connections
+ * and pass them to ClientManager.
+ */
+class Server {
+        private Thread thread;
+        private Logger logger;
+        ServerSocket socket;
+        ClientManager clientManager;
+
+        public this(ClientManager cm)
+        in {
+                assert(cm);
+        } body {
+                this.clientManager = cm;
+
+                logger = Log.getLogger("server");
+
+                logger.info("creating socket");
+                socket = new ServerSocket(new InternetAddress("0.0.0.0", 0));
+                logger.info("listening on " ~ socket.getSocket().localAddress().toUtf8());
+
+
+                logger.info("creating thread");
+                thread = new Thread(&this.serverLoop);
+
+                logger.info("starting thread");
+                thread.start();
+        }
+
+        private void serverLoop() {
+                while (true) {
+                        auto client_socket = socket.accept();
+                        clientManager.spawn(client_socket);
+                }
+        }
+
+        public void join() {
+                thread.join();
+        }
+
+}
+
+int main() {
+
+        Logger logger = Log.getRootLogger();
+        logger.setLevel();
+        logger.addAppender(new ConsoleAppender);
+
+        auto ch = new ClientManager();
+        auto a = new Server(ch);
+        a.join();
+        return 0;
+}
+