* Removed unnecessary conditional

* Optimized the use of memory bandwidth in NioWorker.read

src/main/java/org/jboss/netty/buffer/ByteBufferBackedChannelBuffer.java

@@ -204,7 +204,7 @@ public class ByteBufferBackedChannelBuffer extends AbstractChannelBuffer {
             return;
         }
 
-        if (!buffer.isReadOnly() && buffer.hasArray()) {
+        if (buffer.hasArray()) {
             out.write(
                     buffer.array(),
                     index + buffer.arrayOffset(),

src/main/java/org/jboss/netty/channel/socket/nio/NioWorker.java

@@ -306,37 +306,18 @@ class NioWorker implements Runnable {
     }
 
     private boolean read(SelectionKey k) {
-        SocketChannel ch = (SocketChannel) k.channel();
+        final SocketChannel ch = (SocketChannel) k.channel();
-        NioSocketChannel channel = (NioSocketChannel) k.attachment();
+        final NioSocketChannel channel = (NioSocketChannel) k.attachment();
 
-        ReceiveBufferSizePredictor predictor =
+        final ReceiveBufferSizePredictor predictor =
             channel.getConfig().getReceiveBufferSizePredictor();
-        ChannelBufferFactory bufferFactory =
+        final int predictedRecvBufSize = predictor.nextReceiveBufferSize();
-            channel.getConfig().getBufferFactory();
-
-        ChannelBuffer buffer =
-            bufferFactory.getBuffer(predictor.nextReceiveBufferSize());
 
         int ret = 0;
         int readBytes = 0;
         boolean failure = true;
 
-        if (buffer.isDirect()) {
+        ByteBuffer bb = recvBufferPool.acquire(predictedRecvBufSize);
-            try {
-                while ((ret = buffer.writeBytes(ch, buffer.writableBytes())) > 0) {
-                    readBytes += ret;
-                    if (!buffer.writable()) {
-                        break;
-                    }
-                }
-                failure = false;
-            } catch (ClosedChannelException e) {
-                // Can happen, and does not need a user attention.
-            } catch (Throwable t) {
-                fireExceptionCaught(channel, t);
-            }
-        } else {
-            ByteBuffer bb = recvBufferPool.acquire(buffer.writableBytes());
         try {
             while ((ret = ch.read(bb)) > 0) {
                 readBytes += ret;
@@ -349,19 +330,25 @@ class NioWorker implements Runnable {
             // Can happen, and does not need a user attention.
         } catch (Throwable t) {
             fireExceptionCaught(channel, t);
-            } finally {
-                bb.flip();
-                buffer.writeBytes(bb);
-                recvBufferPool.release(bb);
-            }
         }
 
         if (readBytes > 0) {
+            bb.flip();
+
+            final ChannelBufferFactory bufferFactory =
+                channel.getConfig().getBufferFactory();
+            final ChannelBuffer buffer = bufferFactory.getBuffer(
+                    bb.order(bufferFactory.getDefaultOrder()));
+
+            recvBufferPool.release(bb);
+
             // Update the predictor.
             predictor.previousReceiveBufferSize(readBytes);
 
             // Fire the event.
             fireMessageReceived(channel, buffer);
+        } else {
+            recvBufferPool.release(bb);
         }
 
         if (ret < 0 || failure) {

src/main/java/org/jboss/netty/channel/socket/nio/SocketReceiveBufferPool.java

@@ -25,7 +25,7 @@ import java.nio.ByteBuffer;
  */
 final class SocketReceiveBufferPool {
 
-    private static final int POOL_SIZE = 4;
+    private static final int POOL_SIZE = 8;
 
     @SuppressWarnings("unchecked")
     private final SoftReference<ByteBuffer>[] pool = new SoftReference[POOL_SIZE];
@@ -54,13 +54,12 @@ final class SocketReceiveBufferPool {
 
             pool[i] = null;
 
-            buf.rewind();
+            buf.clear();
-            buf.limit(size);
             return buf;
         }
 
         ByteBuffer buf = ByteBuffer.allocateDirect(normalizeCapacity(size));
-        buf.limit(size);
+        buf.clear();
         return buf;
     }