From 4a3c54b0fa8c3122b1005452b2593b71360ed6f2 Mon Sep 17 00:00:00 2001
From: Trustin Lee <trustin@gmail.com>
Date: Thu, 24 May 2012 10:37:51 -0700
Subject: [PATCH] Add UDP_RECEIVE_PACKET_SIZE option for datagram transport

---
 .../java/io/netty/channel/ChannelOption.java  |  3 +++
 .../channel/socket/DatagramChannelConfig.java |  4 ++++
 .../socket/DefaultDatagramChannelConfig.java  | 22 ++++++++++++++++++-
 .../socket/nio/NioDatagramChannel.java        |  3 +--
 4 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/transport/src/main/java/io/netty/channel/ChannelOption.java b/transport/src/main/java/io/netty/channel/ChannelOption.java
index 65362cc5b2..3d89b934ec 100644
--- a/transport/src/main/java/io/netty/channel/ChannelOption.java
+++ b/transport/src/main/java/io/netty/channel/ChannelOption.java
@@ -44,6 +44,9 @@ public class ChannelOption<T> extends UniqueKey<T> {
     public static final ChannelOption<Boolean> IP_MULTICAST_LOOP_DISABLED =
             new ChannelOption<Boolean>("IP_MULTICAST_LOOP_DISABLED", Boolean.class);
 
+    public static final ChannelOption<Integer> UDP_RECEIVE_PACKET_SIZE =
+            new ChannelOption<Integer>("UDP_RECEIVE_PACKET_SIZE", Integer.class);
+
     public static final ChannelOption<Boolean> TCP_NODELAY =
             new ChannelOption<Boolean>("TCP_NODELAY", Boolean.class);
 
diff --git a/transport/src/main/java/io/netty/channel/socket/DatagramChannelConfig.java b/transport/src/main/java/io/netty/channel/socket/DatagramChannelConfig.java
index f379799728..3f3f28d899 100644
--- a/transport/src/main/java/io/netty/channel/socket/DatagramChannelConfig.java
+++ b/transport/src/main/java/io/netty/channel/socket/DatagramChannelConfig.java
@@ -75,6 +75,10 @@ public interface DatagramChannelConfig extends ChannelConfig {
      */
     void setReceiveBufferSize(int receiveBufferSize);
 
+    int getReceivePacketSize();
+
+    void setReceivePacketSize(int receivePacketSize);
+
     /**
      * Gets the traffic class.
      */
diff --git a/transport/src/main/java/io/netty/channel/socket/DefaultDatagramChannelConfig.java b/transport/src/main/java/io/netty/channel/socket/DefaultDatagramChannelConfig.java
index c217980ba6..89aba8988b 100644
--- a/transport/src/main/java/io/netty/channel/socket/DefaultDatagramChannelConfig.java
+++ b/transport/src/main/java/io/netty/channel/socket/DefaultDatagramChannelConfig.java
@@ -33,7 +33,10 @@ import java.util.Map;
  */
 public class DefaultDatagramChannelConfig extends DefaultChannelConfig implements DatagramChannelConfig {
 
+    private static int DEFAULT_RECEIVE_PACKET_SIZE = 2048;
+
     private final DatagramSocket socket;
+    private volatile int receivePacketSize = DEFAULT_RECEIVE_PACKET_SIZE;
 
     /**
      * Creates a new instance.
@@ -50,7 +53,7 @@ public class DefaultDatagramChannelConfig extends DefaultChannelConfig implement
         return getOptions(
                 super.getOptions(),
                 SO_BROADCAST, SO_RCVBUF, SO_SNDBUF, SO_REUSEADDR, IP_MULTICAST_LOOP_DISABLED,
-                IP_MULTICAST_ADDR, IP_MULTICAST_IF, IP_MULTICAST_TTL, IP_TOS);
+                IP_MULTICAST_ADDR, IP_MULTICAST_IF, IP_MULTICAST_TTL, IP_TOS, UDP_RECEIVE_PACKET_SIZE);
     }
 
     @Override
@@ -64,6 +67,9 @@ public class DefaultDatagramChannelConfig extends DefaultChannelConfig implement
         if (option == SO_SNDBUF) {
             return (T) Integer.valueOf(getSendBufferSize());
         }
+        if (option == UDP_RECEIVE_PACKET_SIZE) {
+            return (T) Integer.valueOf(getReceivePacketSize());
+        }
         if (option == SO_REUSEADDR) {
             return (T) Boolean.valueOf(isReuseAddress());
         }
@@ -269,6 +275,20 @@ public class DefaultDatagramChannelConfig extends DefaultChannelConfig implement
         }
     }
 
+    @Override
+    public int getReceivePacketSize() {
+        return receivePacketSize;
+    }
+
+    @Override
+    public void setReceivePacketSize(int receivePacketSize) {
+        if (receivePacketSize <= 0) {
+            throw new IllegalArgumentException(
+                    String.format("receivePacketSize: %d (expected: > 0)", receivePacketSize));
+        }
+        this.receivePacketSize = receivePacketSize;
+    }
+
     @Override
     public int getTimeToLive() {
         if (socket instanceof MulticastSocket) {
diff --git a/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java b/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java
index d8504eb088..65154f37ba 100644
--- a/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java
+++ b/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java
@@ -174,8 +174,7 @@ public final class NioDatagramChannel extends AbstractNioChannel implements io.n
     @Override
     protected int doRead(ChannelBufferHolder<Object> buf) throws Exception {
         DatagramChannel ch = javaChannel();
-        // FIXME: Make this configurable.
-        ByteBuffer data = ByteBuffer.allocate(1024);
+        ByteBuffer data = ByteBuffer.allocate(config().getReceivePacketSize());
         InetSocketAddress remoteAddress = (InetSocketAddress) ch.receive(data);
         if (remoteAddress == null) {
             return 0;