Ensure that a user implements flush() or inboundBufferUpdated()

- Also prohibited a user from overriding
  ChannelInbound(Byte|Message)HandlerAdapter.  If a user wants to do
  that, he or she should extend ChannelInboundHandlerAdapter instead.

codec/src/main/java/io/netty/handler/codec/ByteToByteDecoder.java

@@ -22,18 +22,18 @@ import io.netty.channel.ChannelInboundByteHandlerAdapter;
 public abstract class ByteToByteDecoder extends ChannelInboundByteHandlerAdapter {
 
     @Override
-    public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
+    public void inboundBufferUpdated(ChannelHandlerContext ctx, ChannelBuffer in) throws Exception {
-        callDecode(ctx);
+        callDecode(ctx, in, ctx.nextOutboundByteBuffer());
     }
 
     @Override
     public void channelInactive(ChannelHandlerContext ctx) throws Exception {
         ChannelBuffer in = ctx.inboundByteBuffer();
+        ChannelBuffer out = ctx.nextInboundByteBuffer();
         if (!in.readable()) {
-            callDecode(ctx);
+            callDecode(ctx, in, out);
         }
 
-        ChannelBuffer out = ctx.nextInboundByteBuffer();
         int oldOutSize = out.readableBytes();
         try {
             decodeLast(ctx, in, out);
@@ -53,10 +53,7 @@ public abstract class ByteToByteDecoder extends ChannelInboundByteHandlerAdapter
         ctx.fireChannelInactive();
     }
 
-    private void callDecode(ChannelHandlerContext ctx) {
+    private void callDecode(ChannelHandlerContext ctx, ChannelBuffer in, ChannelBuffer out) {
-        ChannelBuffer in = ctx.inboundByteBuffer();
-        ChannelBuffer out = ctx.nextInboundByteBuffer();
-
         int oldOutSize = out.readableBytes();
         while (in.readable()) {
             int oldInSize = in.readableBytes();

codec/src/main/java/io/netty/handler/codec/ByteToMessageDecoder.java

@@ -16,12 +16,14 @@
 package io.netty.handler.codec;
 
 import io.netty.buffer.ChannelBuffer;
+import io.netty.channel.ChannelBufferHolder;
+import io.netty.channel.ChannelBufferHolders;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandler;
-import io.netty.channel.ChannelInboundByteHandlerAdapter;
+import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelPipeline;
 
-public abstract class ByteToMessageDecoder<O> extends ChannelInboundByteHandlerAdapter {
+public abstract class ByteToMessageDecoder<O> extends ChannelInboundHandlerAdapter<Byte> {
 
     private ChannelHandlerContext ctx;
 
@@ -31,6 +33,11 @@ public abstract class ByteToMessageDecoder<O> extends ChannelInboundByteHandlerA
         super.beforeAdd(ctx);
     }
 
+    @Override
+    public ChannelBufferHolder<Byte> newInboundBuffer(ChannelHandlerContext ctx) throws Exception {
+        return ChannelBufferHolders.byteBuffer();
+    }
+
     @Override
     public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
         callDecode(ctx);

codec/src/main/java/io/netty/handler/codec/CodecUtil.java

@@ -47,30 +47,30 @@ final class CodecUtil {
         }
 
         if (inbound) {
-            try {
+            if (ctx.hasNextInboundMessageBuffer()) {
                 ctx.nextInboundMessageBuffer().add(msg);
                 return true;
-            } catch (NoSuchBufferException e) {
+            }
-                if (msg instanceof ChannelBuffer) {
+
+            if (msg instanceof ChannelBuffer && ctx.hasNextInboundByteBuffer()) {
                 ChannelBuffer altDst = ctx.nextInboundByteBuffer();
                 ChannelBuffer src = (ChannelBuffer) msg;
                 altDst.writeBytes(src, src.readerIndex(), src.readableBytes());
                 return true;
             }
-            }
         } else {
-            try {
+            if (ctx.hasNextOutboundMessageBuffer()) {
                 ctx.nextOutboundMessageBuffer().add(msg);
                 return true;
-            } catch (NoSuchBufferException e) {
+            }
-                if (msg instanceof ChannelBuffer) {
+
+            if (msg instanceof ChannelBuffer && ctx.hasNextOutboundByteBuffer()) {
                 ChannelBuffer altDst = ctx.nextOutboundByteBuffer();
                 ChannelBuffer src = (ChannelBuffer) msg;
                 altDst.writeBytes(src, src.readerIndex(), src.readableBytes());
                 return true;
             }
         }
-        }
 
         throw new NoSuchBufferException();
     }

codec/src/main/java/io/netty/handler/codec/MessageToMessageDecoder.java

@@ -15,12 +15,19 @@
  */
 package io.netty.handler.codec;
 
+import io.netty.channel.ChannelBufferHolder;
+import io.netty.channel.ChannelBufferHolders;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundMessageHandlerAdapter;
+import io.netty.channel.ChannelInboundHandlerAdapter;
 
 import java.util.Queue;
 
-public abstract class MessageToMessageDecoder<I, O> extends ChannelInboundMessageHandlerAdapter<I> {
+public abstract class MessageToMessageDecoder<I, O> extends ChannelInboundHandlerAdapter<I> {
+
+    @Override
+    public ChannelBufferHolder<I> newInboundBuffer(ChannelHandlerContext ctx) throws Exception {
+        return ChannelBufferHolders.messageBuffer();
+    }
 
     @Override
     public void inboundBufferUpdated(ChannelHandlerContext ctx)

example/src/main/java/io/netty/example/portunification/PortUnificationServerHandler.java

@@ -53,16 +53,14 @@ public class PortUnificationServerHandler extends ChannelInboundByteHandlerAdapt
     }
 
     @Override
-    public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
+    public void inboundBufferUpdated(ChannelHandlerContext ctx, ChannelBuffer in) throws Exception {
-        ChannelBuffer buffer = ctx.inboundByteBuffer();
-
         // Will use the first two bytes to detect a protocol.
-        if (buffer.readableBytes() < 2) {
+        if (in.readableBytes() < 2) {
             return;
         }
 
-        final int magic1 = buffer.getUnsignedByte(buffer.readerIndex());
+        final int magic1 = in.getUnsignedByte(in.readerIndex());
-        final int magic2 = buffer.getUnsignedByte(buffer.readerIndex() + 1);
+        final int magic2 = in.getUnsignedByte(in.readerIndex() + 1);
 
         if (isSsl(magic1)) {
             enableSsl(ctx);
@@ -74,13 +72,13 @@ public class PortUnificationServerHandler extends ChannelInboundByteHandlerAdapt
             switchToFactorial(ctx);
         } else {
             // Unknown protocol; discard everything and close the connection.
-            buffer.clear();
+            in.clear();
             ctx.close();
             return;
         }
 
         // Forward the current read buffer as is to the new handlers.
-        ctx.nextInboundByteBuffer().writeBytes(buffer);
+        ctx.nextInboundByteBuffer().writeBytes(in);
         ctx.fireInboundBufferUpdated();
     }
 

example/src/main/java/io/netty/example/proxy/HexDumpProxyBackendHandler.java

@@ -34,8 +34,7 @@ public class HexDumpProxyBackendHandler extends ChannelInboundByteHandlerAdapter
     }
 
     @Override
-    public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
+    public void inboundBufferUpdated(ChannelHandlerContext ctx, ChannelBuffer in) throws Exception {
-        ChannelBuffer in = ctx.inboundByteBuffer();
         ChannelBuffer out = inboundChannel.outboundByteBuffer();
         out.discardReadBytes();
         out.writeBytes(in);

example/src/main/java/io/netty/example/proxy/HexDumpProxyFrontendHandler.java

@@ -66,8 +66,7 @@ public class HexDumpProxyFrontendHandler extends ChannelInboundByteHandlerAdapte
     }
 
     @Override
-    public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
+    public void inboundBufferUpdated(ChannelHandlerContext ctx, ChannelBuffer in) throws Exception {
-        ChannelBuffer in = ctx.inboundByteBuffer();
         ChannelBuffer out = outboundChannel.outboundByteBuffer();
         out.discardReadBytes();
         out.writeBytes(in);

handler/src/main/java/io/netty/handler/queue/BlockingReadHandler.java

@@ -218,4 +218,10 @@ public class BlockingReadHandler<E> extends ChannelInboundMessageHandlerAdapter<
             queue.add(e);
         }
     }
+
+    @Override
+    public void messageReceived(ChannelHandlerContext ctx, Object msg) throws Exception {
+        // TODO Auto-generated method stub
+
+    }
 }

handler/src/test/java/io/netty/handler/stream/ChunkedWriteHandlerTest.java

@@ -144,11 +144,8 @@ public class ChunkedWriteHandlerTest {
 
             @Override
             public void flush(ChannelHandlerContext ctx, ChannelFuture future) throws Exception {
-                super.flush(ctx, future);
-
                 future.setSuccess();
             }
-
         };
 
         EmbeddedMessageChannel ch = new EmbeddedMessageChannel(new ChunkedWriteHandler(), testHandler);

testsuite/src/test/java/io/netty/testsuite/transport/socket/SocketSpdyEchoTest.java

@@ -22,8 +22,8 @@ import io.netty.buffer.ChannelBuffer;
 import io.netty.buffer.ChannelBuffers;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundMessageHandlerAdapter;
 import io.netty.channel.ChannelInboundByteHandlerAdapter;
+import io.netty.channel.ChannelInboundMessageHandlerAdapter;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.handler.codec.spdy.SpdyConstants;
@@ -255,10 +255,9 @@ public class SocketSpdyEchoTest extends AbstractSocketTest {
         }
 
         @Override
-        public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
+        public void inboundBufferUpdated(ChannelHandlerContext ctx, ChannelBuffer in) throws Exception {
-            ChannelBuffer m = ctx.inboundByteBuffer();
+            byte[] actual = new byte[in.readableBytes()];
-            byte[] actual = new byte[m.readableBytes()];
+            in.readBytes(actual);
-            m.readBytes(actual);
 
             int lastIdx = counter;
             for (int i = 0; i < actual.length; i ++) {

transport/src/main/java/io/netty/bootstrap/ServerBootstrap.java

@@ -16,12 +16,14 @@
 package io.netty.bootstrap;
 
 import io.netty.channel.Channel;
+import io.netty.channel.ChannelBufferHolder;
+import io.netty.channel.ChannelBufferHolders;
 import io.netty.channel.ChannelException;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundMessageHandlerAdapter;
+import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.ChannelPipeline;
@@ -228,7 +230,11 @@ public class ServerBootstrap {
         validate();
     }
 
-    private class Acceptor extends ChannelInboundMessageHandlerAdapter<Channel> {
+    private class Acceptor extends ChannelInboundHandlerAdapter<Channel> {
+        @Override
+        public ChannelBufferHolder<Channel> newInboundBuffer(ChannelHandlerContext ctx) throws Exception {
+            return ChannelBufferHolders.messageBuffer();
+        }
 
         @Override
         public void inboundBufferUpdated(ChannelHandlerContext ctx) {

transport/src/main/java/io/netty/channel/ChannelHandlerAdapter.java

@@ -15,10 +15,7 @@
  */
 package io.netty.channel;
 
-import io.netty.buffer.ChannelBuffer;
-
 import java.net.SocketAddress;
-import java.util.Queue;
 
 public class ChannelHandlerAdapter extends ChannelStateHandlerAdapter implements ChannelOperationHandler {
 
@@ -51,27 +48,11 @@ public class ChannelHandlerAdapter extends ChannelStateHandlerAdapter implements
 
     @Override
     public void flush(ChannelHandlerContext ctx, ChannelFuture future) throws Exception {
-        flush0(ctx, future);
+        if (this instanceof ChannelOutboundHandler) {
+            throw new IllegalStateException(
+                    "flush(...) must be overridden by " + getClass().getName() +
+                    ", which implements " + ChannelOutboundHandler.class.getSimpleName());
         }
-
-    static <O> void flush0(ChannelHandlerContext ctx, ChannelFuture future) {
-        if (ctx.hasOutboundMessageBuffer()) {
-            Queue<O> out = ctx.outboundMessageBuffer();
-            Queue<Object> nextOut = ctx.nextOutboundMessageBuffer();
-            for (;;) {
-                O msg = out.poll();
-                if (msg == null) {
-                    break;
-                }
-                nextOut.add(msg);
-            }
-        } else if (ctx.hasOutboundByteBuffer()) {
-            ChannelBuffer out = ctx.outboundByteBuffer();
-            ChannelBuffer nextOut = ctx.nextOutboundByteBuffer();
-            nextOut.writeBytes(out);
-            out.discardReadBytes();
-        }
-
         ctx.flush(future);
     }
 }

transport/src/main/java/io/netty/channel/ChannelInboundByteHandlerAdapter.java

@@ -18,7 +18,7 @@ package io.netty.channel;
 import io.netty.buffer.ChannelBuffer;
 
 
-public class ChannelInboundByteHandlerAdapter extends ChannelInboundHandlerAdapter<Byte> {
+public abstract class ChannelInboundByteHandlerAdapter extends ChannelInboundHandlerAdapter<Byte> {
 
     @Override
     public ChannelBufferHolder<Byte> newInboundBuffer(ChannelHandlerContext ctx) throws Exception {
@@ -26,12 +26,16 @@ public class ChannelInboundByteHandlerAdapter extends ChannelInboundHandlerAdapt
     }
 
     @Override
-    public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
+    public final void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
-        inboundBufferUpdated(ctx, ctx.inboundByteBuffer());
+        ChannelBuffer in = ctx.inboundByteBuffer();
-    }
+        try {
-
+            inboundBufferUpdated(ctx, in);
-    public void inboundBufferUpdated(ChannelHandlerContext ctx, ChannelBuffer in) throws Exception {
+        } finally {
-        ctx.nextInboundByteBuffer().writeBytes(in);
+            if (!in.readable()) {
                 in.discardReadBytes();
             }
+        }
+    }
+
+    public abstract void inboundBufferUpdated(ChannelHandlerContext ctx, ChannelBuffer in) throws Exception;
 }

transport/src/main/java/io/netty/channel/ChannelInboundHandlerAdapter.java

@@ -18,5 +18,6 @@ package io.netty.channel;
 
 public abstract class ChannelInboundHandlerAdapter<I> extends ChannelStateHandlerAdapter
         implements ChannelInboundHandler<I> {
-    // Useful when you have to create an anonymous class
+    @Override
+    public abstract void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception;
 }

transport/src/main/java/io/netty/channel/ChannelInboundMessageHandlerAdapter.java

@@ -17,7 +17,7 @@ package io.netty.channel;
 
 import java.util.Queue;
 
-public class ChannelInboundMessageHandlerAdapter<I> extends ChannelInboundHandlerAdapter<I> {
+public abstract class ChannelInboundMessageHandlerAdapter<I> extends ChannelInboundHandlerAdapter<I> {
 
     @Override
     public ChannelBufferHolder<I> newInboundBuffer(ChannelHandlerContext ctx) throws Exception {
@@ -25,7 +25,7 @@ public class ChannelInboundMessageHandlerAdapter<I> extends ChannelInboundHandle
     }
 
     @Override
-    public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
+    public final void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
         Queue<I> in = ctx.inboundMessageBuffer();
         for (;;) {
             I msg = in.poll();
@@ -34,14 +34,11 @@ public class ChannelInboundMessageHandlerAdapter<I> extends ChannelInboundHandle
             }
             try {
                 messageReceived(ctx, msg);
-                ctx.fireInboundBufferUpdated();
             } catch (Throwable t) {
                 ctx.fireExceptionCaught(t);
             }
         }
     }
 
-    public void messageReceived(ChannelHandlerContext ctx, I msg) throws Exception {
+    public abstract void messageReceived(ChannelHandlerContext ctx, I msg) throws Exception;
-        ctx.nextInboundMessageBuffer().add(msg);
-    }
 }

transport/src/main/java/io/netty/channel/ChannelOperationHandlerAdapter.java

@@ -84,6 +84,11 @@ public class ChannelOperationHandlerAdapter implements ChannelOperationHandler {
     @Override
     public void flush(ChannelHandlerContext ctx, ChannelFuture future)
             throws Exception {
-        ChannelHandlerAdapter.flush0(ctx, future);
+        if (this instanceof ChannelOutboundHandler) {
+            throw new IllegalStateException(
+                    "flush(...) must be overridden by " + getClass().getName() +
+                    ", which implements " + ChannelOutboundHandler.class.getSimpleName());
+        }
+        ctx.flush(future);
     }
 }

transport/src/main/java/io/netty/channel/ChannelOutboundByteHandlerAdapter.java

@@ -15,7 +15,7 @@
  */
 package io.netty.channel;
 
-public class ChannelOutboundByteHandlerAdapter extends ChannelOutboundHandlerAdapter<Byte> {
+public abstract class ChannelOutboundByteHandlerAdapter extends ChannelOutboundHandlerAdapter<Byte> {
     @Override
     public ChannelBufferHolder<Byte> newOutboundBuffer(ChannelHandlerContext ctx) throws Exception {
         return ChannelBufferHolders.byteBuffer();

transport/src/main/java/io/netty/channel/ChannelOutboundHandlerAdapter.java

@@ -15,8 +15,8 @@
  */
 package io.netty.channel;
 
-
 public abstract class ChannelOutboundHandlerAdapter<O>
         extends ChannelOperationHandlerAdapter implements ChannelOutboundHandler<O> {
-    // Useful when you have to create an anonymous class
+    @Override
+    public abstract void flush(ChannelHandlerContext ctx, ChannelFuture future) throws Exception;
 }

transport/src/main/java/io/netty/channel/ChannelOutboundMessageHandlerAdapter.java

@@ -16,7 +16,7 @@
 package io.netty.channel;
 
 
-public class ChannelOutboundMessageHandlerAdapter<I> extends ChannelOutboundHandlerAdapter<I> {
+public abstract class ChannelOutboundMessageHandlerAdapter<I> extends ChannelOutboundHandlerAdapter<I> {
     @Override
     public ChannelBufferHolder<I> newOutboundBuffer(ChannelHandlerContext ctx) throws Exception {
         return ChannelBufferHolders.messageBuffer();

transport/src/main/java/io/netty/channel/ChannelStateHandlerAdapter.java

@@ -15,9 +15,6 @@
  */
 package io.netty.channel;
 
-import io.netty.buffer.ChannelBuffer;
-
-import java.util.Queue;
 
 public class ChannelStateHandlerAdapter implements ChannelStateHandler {
 
@@ -82,28 +79,11 @@ public class ChannelStateHandlerAdapter implements ChannelStateHandler {
 
     @Override
     public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
-        inboundBufferUpdated0(ctx);
+        if (this instanceof ChannelInboundHandler) {
+            throw new IllegalStateException(
+                    "inboundBufferUpdated(...) must be overridden by " + getClass().getName() +
+                    ", which implements " + ChannelInboundHandler.class.getSimpleName());
         }
-
-    static <I> void inboundBufferUpdated0(ChannelHandlerContext ctx) {
-        if (ctx.hasInboundMessageBuffer()) {
-            Queue<I> in = ctx.inboundMessageBuffer();
-            Queue<Object> nextIn = ctx.nextInboundMessageBuffer();
-            for (;;) {
-                I msg = in.poll();
-                if (msg == null) {
-                    break;
-                }
-                nextIn.add(msg);
-            }
-        } else if (ctx.hasInboundByteBuffer()) {
-            ChannelBuffer in = ctx.inboundByteBuffer();
-            ChannelBuffer nextIn = ctx.nextInboundByteBuffer();
-            nextIn.writeBytes(in);
-            in.discardReadBytes();
-        }
-
         ctx.fireInboundBufferUpdated();
     }
-
 }