Merge branch 'feat/14-commandrouter-and-commandhandler' into 'main'

Create CommandRouter and CommandHandler to execute request

Closes #17

See merge request cs108-fs26/Gruppe-13!50

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/ServerApp.java

@@ -3,6 +3,7 @@ package ch.unibas.dmi.dbis.cs108.casono.server;
 import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserCleanupJob;
 import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.NetworkManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.CommandRouter;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.events.DisconnectEvent;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.events.EventBus;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.parser.CommandParserDispatcher;
@@ -28,7 +29,9 @@ public class ServerApp {
 
         EventBus eventBus = new EventBus();
         CommandParserDispatcher dispatcher = new CommandParserDispatcher();
-        SessionManager sessionManager = new SessionManager(eventBus, dispatcher);
+        CommandRouter router = new CommandRouter();
+
+        SessionManager sessionManager = new SessionManager(eventBus, dispatcher, router);
         eventBus.subscribe(DisconnectEvent.class, event -> sessionManager.onDisconnect(event));
         NetworkManager networkManager = new NetworkManager(port, sessionManager);
 

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/command/CommandHandler.java

@@ -0,0 +1,7 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.command;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.parser.Request;
+
+public interface CommandHandler<T extends Request> {
+    void execute(T request);
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/command/CommandRouter.java

@@ -0,0 +1,28 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.command;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.parser.Request;
+import java.util.HashMap;
+import java.util.Map;
+
+public class CommandRouter {
+    private final Map<Class<? extends Request>, CommandHandler<?>> handlers = new HashMap<>();
+
+    public <T extends Request> void register(Class<T> request, CommandHandler<T> handler) {
+        handlers.put(request, handler);
+    }
+
+    // Safe, because during registration, it's ensured that the provided CommandHandler only
+    // receives requests it can handle.
+    @SuppressWarnings("unchecked")
+    public void execute(Request request) {
+        CommandHandler<Request> handler =
+                (CommandHandler<Request>) handlers.get(request.getClass());
+
+        if (handler == null) {
+            String requestName = request.getClass().toString();
+            throw new UnknownRequestException(
+                    "Unable to execute request " + requestName + ". Type unknown", requestName);
+        }
+        handler.execute(request);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/command/UnknownRequestException.java

@@ -0,0 +1,14 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.command;
+
+public class UnknownRequestException extends RuntimeException {
+    private final String requestName;
+
+    public UnknownRequestException(String message, String requestName) {
+        super(message);
+        this.requestName = requestName;
+    }
+
+    public String getRequestName() {
+        return requestName;
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/sessions/Session.java

@@ -1,5 +1,6 @@
 package ch.unibas.dmi.dbis.cs108.casono.server.network.sessions;
 
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.CommandRouter;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.events.EventBus;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.parser.CommandParserDispatcher;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.response.PrimitiveResponse;
@@ -14,6 +15,7 @@ public class Session {
     private final TransportLayer transport;
     private final BlockingQueue<PrimitiveResponse> responseQueue;
     private final CommandParserDispatcher dispatcher;
+    private final CommandRouter router;
     private static final int RESPOND_QUEUE_SIZE = 32;
 
     /**
@@ -24,10 +26,14 @@ public class Session {
      * @throws IOException if an I/O error occurs during initialization
      */
     public Session(
-            TransportLayer transport, EventBus eventBus, CommandParserDispatcher dispatcher) {
+            TransportLayer transport,
+            EventBus eventBus,
+            CommandParserDispatcher dispatcher,
+            CommandRouter router) {
         this.id = new SessionId();
         this.transport = transport;
         this.dispatcher = dispatcher;
+        this.router = router;
         this.responseQueue = new ArrayBlockingQueue<>(RESPOND_QUEUE_SIZE);
     }
 
@@ -66,4 +72,8 @@ public class Session {
     public CommandParserDispatcher getDispatcher() {
         return dispatcher;
     }
+
+    public CommandRouter getRouter() {
+        return router;
+    }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/sessions/SessionManager.java

@@ -1,5 +1,6 @@
 package ch.unibas.dmi.dbis.cs108.casono.server.network.sessions;
 
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.CommandRouter;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.events.DisconnectEvent;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.events.EventBus;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.parser.CommandParserDispatcher;
@@ -16,13 +17,16 @@ public class SessionManager {
     private final EventBus eventBus;
     private final Logger logger;
     private final CommandParserDispatcher dispatcher;
+    private final CommandRouter router;
 
     /** Constructs a new SessionManager. */
-    public SessionManager(EventBus eventBus, CommandParserDispatcher dispatcher) {
+    public SessionManager(
+            EventBus eventBus, CommandParserDispatcher dispatcher, CommandRouter router) {
         this.sessions = new ConcurrentHashMap<>();
         this.eventBus = eventBus;
         this.logger = LogManager.getLogger(SessionManager.class);
         this.dispatcher = dispatcher;
+        this.router = router;
     }
 
     /**
@@ -34,16 +38,18 @@ public class SessionManager {
      * @return newly created session
      */
     public Session create(TransportLayer transport) {
-        Session session = new Session(transport, eventBus, dispatcher);
+        Session session = new Session(transport, eventBus, dispatcher, router);
         SessionReader reader = new SessionReader(session, eventBus);
         SessionWriter writer = new SessionWriter(session);
 
-        Thread readerThread = Thread.ofVirtual()
-            .name("session-" + session.getId().value() + "-reader")
-            .unstarted(reader);
-        Thread writerThread = Thread.ofVirtual()
-            .name("session-" + session.getId().value() + "-writer")
-            .unstarted(writer);
+        Thread readerThread =
+                Thread.ofVirtual()
+                        .name("session-" + session.getId().value() + "-reader")
+                        .unstarted(reader);
+        Thread writerThread =
+                Thread.ofVirtual()
+                        .name("session-" + session.getId().value() + "-writer")
+                        .unstarted(writer);
 
         sessions.put(session.getId(), new SessionHandle(session, readerThread, writerThread));
         readerThread.start();

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/sessions/SessionReader.java

@@ -1,5 +1,6 @@
 package ch.unibas.dmi.dbis.cs108.casono.server.network.sessions;
 
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.CommandRouter;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.events.DisconnectEvent;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.events.EventBus;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.parser.CommandParserDispatcher;
@@ -22,6 +23,7 @@ public class SessionReader implements Runnable {
     private final TransportLayer transport;
     private final EventBus eventBus;
     private final CommandParserDispatcher dispatcher;
+    private final CommandRouter router;
     private final Logger logger;
 
     public SessionReader(Session session, EventBus eventBus) {
@@ -29,6 +31,7 @@ public class SessionReader implements Runnable {
         this.transport = session.getTransport();
         this.eventBus = eventBus;
         this.dispatcher = session.getDispatcher();
+        this.router = session.getRouter();
         this.logger =
                 LogManager.getLogger(
                         SessionReader.class.toString() + "-" + session.getId().value());
@@ -50,8 +53,11 @@ public class SessionReader implements Runnable {
                 PrimitiveRequest primitiveRequest =
                         new PrimitiveRequest(
                                 requestContext, rawRequest.command(), rawRequest.parameters());
+                logger.debug("Converted to {}", primitiveRequest);
 
                 Request request = dispatcher.parse(primitiveRequest);
+
+                router.execute(request);
             } catch (EOFException e) {
                 logger.info("Client disconnected");
                 eventBus.publish(new DisconnectEvent(session.getId()));