Split AbstractChannel.doFlush() into two variants for simpler user impl

- Also renamed doRead() to doReadMessages() and doReadBytes()

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

@@ -647,7 +647,7 @@ public abstract class AbstractChannel extends DefaultAttributeMap implements Cha
                 if (buf.hasMessageBuffer()) {
                     Queue<Object> msgBuf = buf.messageBuffer();
                     for (;;) {
-                        int localReadAmount = doRead(msgBuf);
+                        int localReadAmount = doReadMessages(msgBuf);
                         if (localReadAmount > 0) {
                             read = true;
                         } else if (localReadAmount == 0) {
@@ -660,7 +660,7 @@ public abstract class AbstractChannel extends DefaultAttributeMap implements Cha
                 } else {
                     ChannelBuffer byteBuf = buf.byteBuffer();
                     for (;;) {
-                        int localReadAmount = doRead(byteBuf);
+                        int localReadAmount = doReadBytes(byteBuf);
                         if (localReadAmount > 0) {
                             read = true;
                         } else if (localReadAmount < 0) {
@@ -750,8 +750,14 @@ public abstract class AbstractChannel extends DefaultAttributeMap implements Cha
         }
 
         private void flushByteBuf(ChannelBuffer buf) throws Exception {
+            if (!buf.readable()) {
+                // Reset reader/writerIndex to 0 if the buffer is empty.
+                buf.clear();
+                return;
+            }
+
             for (int i = config().getWriteSpinCount() - 1; i >= 0; i --) {
-                int localFlushedAmount = doFlush(i == 0);
+                int localFlushedAmount = doWriteBytes(buf, i == 0);
                 if (localFlushedAmount > 0) {
                     flushedAmount += localFlushedAmount;
                     notifyFlushFutures();
@@ -770,7 +776,7 @@ public abstract class AbstractChannel extends DefaultAttributeMap implements Cha
             while (!buf.isEmpty()) {
                 boolean wrote = false;
                 for (int i = writeSpinCount; i >= 0; i --) {
-                    int localFlushedAmount = doFlush(i == 0);
+                    int localFlushedAmount = doWriteMessages(buf, i == 0);
                     if (localFlushedAmount > 0) {
                         flushedAmount += localFlushedAmount;
                         wrote = true;
@@ -915,9 +921,22 @@ public abstract class AbstractChannel extends DefaultAttributeMap implements Cha
     protected abstract void doClose() throws Exception;
     protected abstract void doDeregister() throws Exception;
 
-    protected abstract int doRead(Queue<Object> buf) throws Exception;
+    protected int doReadMessages(Queue<Object> buf) throws Exception {
-    protected abstract int doRead(ChannelBuffer buf) throws Exception;
+        throw new UnsupportedOperationException();
-    protected abstract int doFlush(boolean lastSpin) throws Exception;
+    }
+
+    protected int doReadBytes(ChannelBuffer buf) throws Exception {
+        throw new UnsupportedOperationException();
+    }
+
+    protected int doWriteMessages(Queue<Object> buf, boolean lastSpin) throws Exception {
+        throw new UnsupportedOperationException();
+    }
+
+    protected int doWriteBytes(ChannelBuffer buf, boolean lastSpin) throws Exception {
+        throw new UnsupportedOperationException();
+    }
+
     protected abstract boolean inEventLoopDrivenFlush();
 
     private static boolean expandReadBuffer(ChannelBuffer byteBuf) {

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

@@ -15,8 +15,6 @@
  */
 package io.netty.channel;
 
-import io.netty.buffer.ChannelBuffer;
-
 import java.net.SocketAddress;
 import java.util.AbstractQueue;
 import java.util.Collections;
@@ -78,16 +76,6 @@ public abstract class AbstractServerChannel extends AbstractChannel implements S
         throw new UnsupportedOperationException();
     }
 
-    @Override
-    protected int doRead(ChannelBuffer buf) throws Exception {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    protected int doFlush(boolean lastSpin) throws Exception {
-        throw new UnsupportedOperationException();
-    }
-
     @Override
     protected boolean inEventLoopDrivenFlush() {
         return false;

transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java

@@ -15,7 +15,6 @@
  */
 package io.netty.channel.socket.nio;
 
-import io.netty.buffer.ChannelBuffer;
 import io.netty.buffer.ChannelBuffers;
 import io.netty.channel.ChannelBufferHolder;
 import io.netty.channel.ChannelBufferHolders;
@@ -173,7 +172,7 @@ public final class NioDatagramChannel extends AbstractNioChannel implements io.n
     }
 
     @Override
-    protected int doRead(Queue<Object> buf) throws Exception {
+    protected int doReadMessages(Queue<Object> buf) throws Exception {
         DatagramChannel ch = javaChannel();
         ByteBuffer data = ByteBuffer.allocate(config().getReceivePacketSize());
         InetSocketAddress remoteAddress = (InetSocketAddress) ch.receive(data);
@@ -187,17 +186,7 @@ public final class NioDatagramChannel extends AbstractNioChannel implements io.n
     }
 
     @Override
-    protected int doRead(ChannelBuffer buf) throws Exception {
+    protected int doWriteMessages(Queue<Object> buf, boolean lastSpin) throws Exception {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    protected int doFlush(boolean lastSpin) throws Exception {
-        final Queue<Object> buf = unsafe().out().messageBuffer();
-        if (buf.isEmpty()) {
-            return 0;
-        }
-
         DatagramPacket packet = (DatagramPacket) buf.peek();
         final int writtenBytes = javaChannel().send(packet.data().toByteBuffer(), packet.remoteAddress());
 

transport/src/main/java/io/netty/channel/socket/nio/NioServerSocketChannel.java

@@ -128,7 +128,7 @@ public class NioServerSocketChannel extends AbstractServerChannel
     }
 
     @Override
-    protected int doRead(Queue<Object> buf) throws Exception {
+    protected int doReadMessages(Queue<Object> buf) throws Exception {
         java.nio.channels.SocketChannel ch = javaChannel().accept();
         if (ch == null) {
             return 0;

transport/src/main/java/io/netty/channel/socket/nio/NioSocketChannel.java

@@ -29,7 +29,6 @@ import java.io.IOException;
 import java.net.SocketAddress;
 import java.nio.channels.SelectionKey;
 import java.nio.channels.SocketChannel;
-import java.util.Queue;
 
 public class NioSocketChannel extends AbstractNioChannel implements io.netty.channel.socket.SocketChannel {
 
@@ -160,23 +159,13 @@ public class NioSocketChannel extends AbstractNioChannel implements io.netty.cha
     }
 
     @Override
-    protected int doRead(ChannelBuffer byteBuf) throws Exception {
+    protected int doReadBytes(ChannelBuffer byteBuf) throws Exception {
         return byteBuf.writeBytes(javaChannel(), byteBuf.writableBytes());
     }
 
     @Override
-    protected int doRead(Queue<Object> buf) throws Exception {
+    protected int doWriteBytes(ChannelBuffer buf, boolean lastSpin) throws Exception {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    protected int doFlush(boolean lastSpin) throws Exception {
-        final ChannelBuffer buf = unsafe().out().byteBuffer();
         final int expectedWrittenBytes = buf.readableBytes();
-        if (expectedWrittenBytes == 0) {
-            return 0;
-        }
-
         final int writtenBytes = buf.readBytes(javaChannel(), expectedWrittenBytes);
 
         final SelectionKey key = selectionKey();

transport/src/main/java/io/netty/channel/socket/oio/OioDatagramChannel.java

@@ -194,7 +194,7 @@ public class OioDatagramChannel extends AbstractChannel
     }
 
     @Override
-    protected int doRead(Queue<Object> buf) throws Exception {
+    protected int doReadMessages(Queue<Object> buf) throws Exception {
         int packetSize = config().getReceivePacketSize();
         byte[] data = new byte[packetSize];
         tmpPacket.setData(data);
@@ -214,17 +214,7 @@ public class OioDatagramChannel extends AbstractChannel
     }
 
     @Override
-    protected int doRead(ChannelBuffer buf) throws Exception {
+    protected int doWriteMessages(Queue<Object> buf, boolean lastSpin) throws Exception {
-        throw new Error();
-    }
-
-    @Override
-    protected int doFlush(boolean lastSpin) throws Exception {
-        final Queue<Object> buf = unsafe().out().messageBuffer();
-        if (buf.isEmpty()) {
-            return 0;
-        }
-
         DatagramPacket p = (DatagramPacket) buf.poll();
         ChannelBuffer data = p.data();
         int length = data.readableBytes();

transport/src/main/java/io/netty/channel/socket/oio/OioServerSocketChannel.java

@@ -152,7 +152,7 @@ public class OioServerSocketChannel extends AbstractServerChannel
     }
 
     @Override
-    protected int doRead(Queue<Object> buf) throws Exception {
+    protected int doReadMessages(Queue<Object> buf) throws Exception {
         if (socket.isClosed()) {
             return -1;
         }

transport/src/main/java/io/netty/channel/socket/oio/OioSocketChannel.java

@@ -187,12 +187,12 @@ public class OioSocketChannel extends AbstractChannel
     }
 
     @Override
-    protected int doRead(Queue<Object> buf) throws Exception {
+    protected int doReadMessages(Queue<Object> buf) throws Exception {
         throw new Error();
     }
 
     @Override
-    protected int doRead(ChannelBuffer buf) throws Exception {
+    protected int doReadBytes(ChannelBuffer buf) throws Exception {
         if (socket.isClosed()) {
             return -1;
         }
@@ -206,16 +206,12 @@ public class OioSocketChannel extends AbstractChannel
     }
 
     @Override
-    protected int doFlush(boolean lastSpin) throws Exception {
+    protected int doWriteBytes(ChannelBuffer buf, boolean lastSpin) throws Exception {
         OutputStream os = this.os;
         if (os == null) {
             throw new NotYetConnectedException();
         }
-        final ChannelBuffer buf = unsafe().out().byteBuffer();
         final int length = buf.readableBytes();
-        if (length == 0) {
-            return 0;
-        }
         buf.readBytes(os, length);
         return length;
     }