* Un-deprecated NioSocketChannelConfig.receiveBufferSizePredictor to resolve the FIXME related with buffer creation

* Removed the usage of pre-allocated buffers (reverted back to old behavior)

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

@@ -44,11 +44,10 @@ class DefaultNioSocketChannelConfig extends DefaultSocketChannelConfig
     private static final InternalLogger logger =
         InternalLoggerFactory.getInstance(DefaultNioSocketChannelConfig.class);
 
-    private static final ReceiveBufferSizePredictor UNUSED_PREDICTOR =
-        new DefaultReceiveBufferSizePredictor();
-
     private volatile int writeBufferHighWaterMark = 64 * 1024;
     private volatile int writeBufferLowWaterMark  = 32 * 1024;
+    private volatile ReceiveBufferSizePredictor predictor =
+        new DefaultReceiveBufferSizePredictor();
     private volatile int writeSpinCount = 16;
 
     DefaultNioSocketChannelConfig(Socket socket) {
@@ -116,15 +115,15 @@ class DefaultNioSocketChannelConfig extends DefaultSocketChannelConfig
     }
 
     public ReceiveBufferSizePredictor getReceiveBufferSizePredictor() {
-        logger.warn(
+        return predictor;
-                "Detected an access to a deprecated configuration parameter: " +
-                "receiveBufferSizePredictor");
-        return UNUSED_PREDICTOR;
     }
 
     public void setReceiveBufferSizePredictor(
             ReceiveBufferSizePredictor predictor) {
-        getReceiveBufferSizePredictor();
+        if (predictor == null) {
+            throw new NullPointerException("predictor");
+        }
+        this.predictor = predictor;
     }
 
     public boolean isReadWriteFair() {

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

@@ -87,23 +87,17 @@ public interface NioSocketChannelConfig extends SocketChannelConfig {
     void setWriteSpinCount(int writeSpinCount);
 
     /**
-     * @deprecated Works fine without prediction since 3.1.
-     *
      * Returns the {@link ReceiveBufferSizePredictor} which predicts the
      * number of readable bytes in the socket receive buffer.  The default
      * predictor is {@link DefaultReceiveBufferSizePredictor}.
      */
-    @Deprecated
     ReceiveBufferSizePredictor getReceiveBufferSizePredictor();
 
     /**
-     * @deprecated Works fine without prediction since 3.1.
-     *
      * Sets the {@link ReceiveBufferSizePredictor} which predicts the
      * number of readable bytes in the socket receive buffer.  The default
      * predictor is {@link DefaultReceiveBufferSizePredictor}.
      */
-    @Deprecated
     void setReceiveBufferSizePredictor(ReceiveBufferSizePredictor predictor);
 
     /**

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

@@ -41,6 +41,7 @@ import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 import org.jboss.netty.buffer.ChannelBuffer;
+import org.jboss.netty.buffer.ChannelBufferFactory;
 import org.jboss.netty.channel.Channel;
 import org.jboss.netty.channel.ChannelException;
 import org.jboss.netty.channel.ChannelFuture;
@@ -255,29 +256,25 @@ class NioWorker implements Runnable {
         }
     }
 
-    private ChannelBuffer preallocatedBuffer;
-
     private static void read(SelectionKey k) {
         ScatteringByteChannel ch = (ScatteringByteChannel) k.channel();
         NioSocketChannel channel = (NioSocketChannel) k.attachment();
 
-        ChannelBuffer preallocatedBuffer = channel.getWorker().preallocatedBuffer;
+        ReceiveBufferSizePredictor predictor =
-        NioWorker worker = channel.getWorker();
+            channel.getConfig().getReceiveBufferSizePredictor();
-        worker.preallocatedBuffer = null;
+        ChannelBufferFactory bufferFactory =
+            channel.getConfig().getBufferFactory();
 
-        if (preallocatedBuffer == null) {
+        ChannelBuffer buffer =
-            // TODO Magic number
+            bufferFactory.getBuffer(predictor.nextReceiveBufferSize());
-            // FIXME: OOPS - the new buffer should not be shared by more than one connection
-            preallocatedBuffer = channel.getConfig().getBufferFactory().getBuffer(1048576);
-        }
 
         int ret = 0;
         int readBytes = 0;
         boolean failure = true;
         try {
-            while ((ret = preallocatedBuffer.writeBytes(ch, preallocatedBuffer.writableBytes())) > 0) {
+            while ((ret = buffer.writeBytes(ch, buffer.writableBytes())) > 0) {
                 readBytes += ret;
-                if (!preallocatedBuffer.writable()) {
+                if (!buffer.writable()) {
                     break;
                 }
             }
@@ -289,17 +286,11 @@ class NioWorker implements Runnable {
         }
 
         if (readBytes > 0) {
+            // Update the predictor.
+            predictor.previousReceiveBufferSize(readBytes);
+
             // Fire the event.
-            ChannelBuffer slice = preallocatedBuffer.slice(
+            fireMessageReceived(channel, buffer);
-                    preallocatedBuffer.readerIndex(),
-                    preallocatedBuffer.readableBytes());
-            preallocatedBuffer.readerIndex(preallocatedBuffer.writerIndex());
-            if (preallocatedBuffer.writable()) {
-                worker.preallocatedBuffer = preallocatedBuffer;
-            }
-            fireMessageReceived(channel, slice);
-        } else if (readBytes == 0) {
-            worker.preallocatedBuffer = preallocatedBuffer;
         }
 
         if (ret < 0 || failure) {