SocketSwitch was not used.

IMessageWriter + IMessageWriterFactory are not necessary, as messages are just buffers
that need to be drained to the socket. Instead we have a standard MessageWriter that does
that.

src/main/java/com/jenkov/nioserver/IMessageWriter.java

@@ -1,23 +0,0 @@
-package com.jenkov.nioserver;
-
-import java.io.IOException;
-import java.nio.ByteBuffer;
-import java.nio.channels.Selector;
-
-/**
- * Created by jjenkov on 16-10-2015.
- */
-public interface IMessageWriter {
-
-    /**
-     * Called by IMessageProcessor - so no access to write Selector from here.
-     *
-     * @param message
-     */
-    public void enqueue(Message message);
-
-    public void write(Socket socket, ByteBuffer byteBuffer) throws IOException;
-
-    public boolean isEmpty();
-
-}

src/main/java/com/jenkov/nioserver/IMessageWriterFactory.java

@@ -1,12 +0,0 @@
-package com.jenkov.nioserver;
-
-import java.nio.channels.Selector;
-
-/**
- * Created by jjenkov on 16-10-2015.
- */
-public interface IMessageWriterFactory {
-
-    public IMessageWriter createMessageWriter();
-
-}

src/main/java/com/jenkov/nioserver/MessageWriter.java

@@ -8,7 +8,7 @@ import java.util.List;
 /**
  * Created by jjenkov on 21-10-2015.
  */
-public class MessageWriter implements IMessageWriter {
+public class MessageWriter {
 
     private List<Message> writeQueue   = new ArrayList<>();
     private Message  messageInProgress = null;
@@ -17,25 +17,15 @@ public class MessageWriter implements IMessageWriter {
     public MessageWriter() {
     }
 
-    @Override
     public void enqueue(Message message) {
         if(this.messageInProgress == null){
             this.messageInProgress = message;
-            System.out.println("Message set as message in progress.");
         } else {
             this.writeQueue.add(message);
-            System.out.println("Message enqueued.");
         }
-
-        //todo register socket for write interest
-
     }
 
-
-    @Override
     public void write(Socket socket, ByteBuffer byteBuffer) throws IOException {
-        System.out.println("Writing message to socket");
-
         byteBuffer.put(this.messageInProgress.sharedArray, this.messageInProgress.offset + this.bytesWritten, this.messageInProgress.length - this.bytesWritten);
         byteBuffer.flip();
 
@@ -52,8 +42,8 @@ public class MessageWriter implements IMessageWriter {
         }
     }
 
-    @Override
     public boolean isEmpty() {
         return this.writeQueue.isEmpty() && this.messageInProgress == null;
     }
+
 }

src/main/java/com/jenkov/nioserver/ServerCore.java

@@ -12,15 +12,16 @@ import java.util.*;
  */
 public class ServerCore implements Runnable {
 
-    private MessageBuffer  readMessageBuffer  = null;
+    private Queue<Socket>  inboundSocketQueue   = null;
-    private MessageBuffer  writeMessageBuffer = null;
-    private Queue<Socket>  inboundSocketQueue = null;
-    private Queue<Message> outboundMessageQueue = new LinkedList<>(); //todo use a better / faster queue.
 
-    private Map<Long, Socket> socketMap       = new HashMap<>();
+    private MessageBuffer  readMessageBuffer    = null; //todo   Not used now - but perhaps will be later - to check for space in the buffer before reading from sockets
+    private MessageBuffer  writeMessageBuffer   = null; //todo   Not used now - but perhaps will be later - to check for space in the buffer before reading from sockets (space for more to write?)
 
     private IMessageReaderFactory messageReaderFactory = null;
-    private IMessageWriterFactory messageWriterFactory = null;
+
+    private Queue<Message> outboundMessageQueue = new LinkedList<>(); //todo use a better / faster queue.
+
+    private Map<Long, Socket> socketMap         = new HashMap<>();
 
     private ByteBuffer readByteBuffer  = ByteBuffer.allocate(1024 * 1024);
     private ByteBuffer writeByteBuffer = ByteBuffer.allocate(1024 * 1024);
@@ -36,7 +37,7 @@ public class ServerCore implements Runnable {
     private Set<Socket> nonEmptyToEmptySockets = new HashSet<>();
 
 
-    public ServerCore(Queue<Socket> inboundSocketQueue, MessageBuffer readMessageBuffer, MessageBuffer writeMessageBuffer, IMessageReaderFactory messageReaderFactory, IMessageWriterFactory messageWriterFactory, IMessageProcessor messageProcessor) throws IOException {
+    public ServerCore(Queue<Socket> inboundSocketQueue, MessageBuffer readMessageBuffer, MessageBuffer writeMessageBuffer, IMessageReaderFactory messageReaderFactory, IMessageProcessor messageProcessor) throws IOException {
         this.inboundSocketQueue = inboundSocketQueue;
 
         this.readMessageBuffer    = readMessageBuffer;
@@ -44,7 +45,6 @@ public class ServerCore implements Runnable {
         this.writeProxy           = new WriteProxy(writeMessageBuffer, this.outboundMessageQueue);
 
         this.messageReaderFactory = messageReaderFactory;
-        this.messageWriterFactory = messageWriterFactory;
 
         this.messageProcessor     = messageProcessor;
 
@@ -84,7 +84,7 @@ public class ServerCore implements Runnable {
             newSocket.socketChannel.configureBlocking(false);
 
             newSocket.messageReader = this.messageReaderFactory.createMessageReader();
-            newSocket.messageWriter = this.messageWriterFactory.createMessageWriter();
+            newSocket.messageWriter = new MessageWriter();
 
             this.socketMap.put(newSocket.socketId, newSocket);
 
@@ -128,6 +128,7 @@ public class ServerCore implements Runnable {
         }
 
         if(socket.endOfStreamReached){
+            System.out.println("Socket closed: " + socket.socketId);
             this.socketMap.remove(socket.socketId);
             key.attach(null);
             key.cancel();
@@ -147,9 +148,7 @@ public class ServerCore implements Runnable {
         // Register all sockets that *have* data and which are not yet registered.
         registerNonEmptySockets();
 
-
         // Select from the Selector.
-
         int writeReady = this.writeSelector.selectNow();
 
         if(writeReady > 0){
@@ -185,6 +184,7 @@ public class ServerCore implements Runnable {
     private void cancelEmptySockets() {
         for(Socket socket : nonEmptyToEmptySockets){
             SelectionKey key = socket.socketChannel.keyFor(this.writeSelector);
+
             key.cancel();
         }
         nonEmptyToEmptySockets.clear();
@@ -196,7 +196,7 @@ public class ServerCore implements Runnable {
             Socket socket = this.socketMap.get(outMessage.socketId);
 
             if(socket != null){
-                IMessageWriter messageWriter = socket.messageWriter;
+                MessageWriter messageWriter = socket.messageWriter;
                 if(messageWriter.isEmpty()){
                     messageWriter.enqueue(outMessage);
                     nonEmptyToEmptySockets.remove(socket);

src/main/java/com/jenkov/nioserver/Socket.java

@@ -11,9 +11,9 @@ public class Socket {
 
     public long socketId;
 
-    public SocketChannel socketChannel = null;
+    public SocketChannel  socketChannel = null;
     public IMessageReader messageReader = null;
-    public IMessageWriter messageWriter = null;
+    public MessageWriter  messageWriter = null;
 
     public boolean endOfStreamReached = false;
 

src/main/java/com/jenkov/nioserver/SocketSwitch.java

@@ -1,87 +0,0 @@
-package com.jenkov.nioserver;
-
-import java.io.IOException;
-import java.nio.ByteBuffer;
-import java.util.*;
-
-/**
- *
- * Todo - rename class to SocketWriter ?
- *
- * Created by jjenkov on 20-10-2015.
- */
-public class SocketSwitch {
-
-    private Map<Long, Socket>         socketMap        = new HashMap<>();
-    private Map<Long, IMessageWriter> messageWriterMap = new HashMap<>();
-
-    private Set<Socket> socketsToCancel   = new HashSet<>();
-    private Set<Socket> socketsToRegister = new HashSet<>();
-
-
-    public Set<Socket> getSocketsToCancel() {
-        return this.socketsToCancel;
-    }
-
-    public Set<Socket> getSocketsToRegister() {
-        return this.socketsToRegister;
-    }
-
-    //todo change putMessageWriter to registerSocket();
-    public void registerSocket(Socket socket){
-        System.out.println("Registering socket: " + socket.socketId );
-        this.socketMap.put(socket.socketId, socket);
-        this.messageWriterMap.put(socket.socketId, socket.messageWriter);
-    }
-
-    public void enqueueMessage(long socketId, Message message){
-        IMessageWriter messageWriter = this.messageWriterMap.get(socketId);
-
-
-
-        if(messageWriter != null){
-            boolean wasEmpty = messageWriter.isEmpty();
-            messageWriter.enqueue(message);
-
-            if(wasEmpty){
-                Socket socket = this.socketMap.get(socketId);
-
-                if(this.socketsToCancel.contains(socket)){
-                    //Socket already registered with Selector. Remove cancellation request but
-                    // do not re-register socket with Selector
-                    this.socketsToCancel.remove(socket);
-                } else {
-                    //Socket not currently registered with Selector. Request registration.
-                    this.socketsToRegister.add(socket);
-                }
-            }
-        }
-    }
-
-    public void writeToSocket(Socket socket, ByteBuffer writeByteBuffer) throws IOException {
-        IMessageWriter messageWriter = messageWriterMap.get(socket.socketId);
-        if(messageWriter != null){
-            messageWriter.write(socket, writeByteBuffer);
-
-            if(messageWriter.isEmpty()) {
-                this.socketsToCancel.add(socket);
-            }
-        }
-
-    }
-
-    public void unregisterSocket(long socketId){
-        System.out.println("Unregistering socket: " + socketId);
-        this.socketMap.remove(socketId);
-
-        //todo in case the message writer should survive a "missing connection" - don't remove it.
-        this.messageWriterMap.remove(socketId);
-    }
-
-    public void removeMessageWriter(long id){
-        this.socketMap.remove(id);
-    }
-
-
-
-}

src/main/java/com/jenkov/nioserver/example/Main.java

@@ -2,7 +2,6 @@ package com.jenkov.nioserver.example;
 
 import com.jenkov.nioserver.*;
 import com.jenkov.nioserver.http.HttpMessageReaderFactory;
-import com.jenkov.nioserver.http.HttpMessageWriterFactory;
 
 import java.io.IOException;
 import java.util.concurrent.ArrayBlockingQueue;
@@ -14,7 +13,6 @@ import java.util.concurrent.BlockingQueue;
 public class Main {
 
     public static void main(String[] args) throws IOException {
-
         BlockingQueue inboundSocketQueue = new ArrayBlockingQueue(1024);
 
         Server server = new Server(9999, inboundSocketQueue);
@@ -22,11 +20,9 @@ public class Main {
         Thread serverThread = new Thread(server);
         serverThread.start();
 
-
         MessageBuffer readMessageBuffer  = new MessageBuffer();
         MessageBuffer writeMessageBuffer = new MessageBuffer();
         IMessageReaderFactory messageReaderFactory = new HttpMessageReaderFactory(readMessageBuffer);
-        IMessageWriterFactory messageWriterFactory = new HttpMessageWriterFactory();
 
         String httpResponse = "HTTP/1.1 200 OK\r\n" +
                 "Content-Length: 38\r\n" +
@@ -46,7 +42,7 @@ public class Main {
             writeProxy.enqueue(response);
         };
 
-        ServerCore serverCore       = new ServerCore(inboundSocketQueue, readMessageBuffer, writeMessageBuffer, messageReaderFactory, messageWriterFactory, messageProcessor);
+        ServerCore serverCore       = new ServerCore(inboundSocketQueue, readMessageBuffer, writeMessageBuffer, messageReaderFactory, messageProcessor);
         Thread     serverCoreThread = new Thread(serverCore);
         serverCoreThread.start();
     }

src/main/java/com/jenkov/nioserver/http/HttpMessageWriter.java

@@ -1,64 +0,0 @@
-package com.jenkov.nioserver.http;
-
-import com.jenkov.nioserver.IMessageWriter;
-import com.jenkov.nioserver.Message;
-import com.jenkov.nioserver.SocketSwitch;
-import com.jenkov.nioserver.Socket;
-
-import java.io.IOException;
-import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * Created by jjenkov on 21-10-2015.
- */
-public class HttpMessageWriter implements IMessageWriter {
-
-    private List<Message> writeQueue   = new ArrayList<>();
-    private Message  messageInProgress = null;
-    private int      bytesWritten      =    0;
-
-    public HttpMessageWriter() {
-    }
-
-    @Override
-    public void enqueue(Message message) {
-        if(this.messageInProgress == null){
-            this.messageInProgress = message;
-            System.out.println("Message set as message in progress.");
-        } else {
-            this.writeQueue.add(message);
-            System.out.println("Message enqueued.");
-        }
-
-        //todo register socket for write interest
-
-    }
-
-
-    @Override
-    public void write(Socket socket, ByteBuffer byteBuffer) throws IOException {
-        System.out.println("Writing message to socket");
-
-        byteBuffer.put(this.messageInProgress.sharedArray, this.messageInProgress.offset + this.bytesWritten, this.messageInProgress.length - this.bytesWritten);
-        byteBuffer.flip();
-
-        this.bytesWritten += socket.write(byteBuffer);
-        byteBuffer.clear();
-
-        if(bytesWritten >= this.messageInProgress.length){
-            if(this.writeQueue.size() > 0){
-                this.messageInProgress = this.writeQueue.remove(0);
-            } else {
-                this.messageInProgress = null;
-                //todo unregister from selector
-            }
-        }
-    }
-
-    @Override
-    public boolean isEmpty() {
-        return this.writeQueue.isEmpty() && this.messageInProgress == null;
-    }
-}

src/main/java/com/jenkov/nioserver/http/HttpMessageWriterFactory.java

@@ -1,18 +0,0 @@
-package com.jenkov.nioserver.http;
-
-import com.jenkov.nioserver.IMessageWriter;
-import com.jenkov.nioserver.IMessageWriterFactory;
-
-import java.nio.channels.Selector;
-
-/**
- * Created by jjenkov on 19-10-2015.
- */
-public class HttpMessageWriterFactory implements IMessageWriterFactory {
-
-    @Override
-    public IMessageWriter createMessageWriter() {
-        return new HttpMessageWriter();
-        //return null;
-    }
-}