XHRPolling "write once" optimization.

src/main/java/com/corundumstudio/socketio/handler/EncoderHandler.java

@@ -54,12 +54,11 @@ import com.corundumstudio.socketio.messages.XHRErrorMessage;
 import com.corundumstudio.socketio.messages.XHROutMessage;
 import com.corundumstudio.socketio.messages.XHRSendPacketsMessage;
 import com.corundumstudio.socketio.parser.Encoder;
+import com.corundumstudio.socketio.transport.XHRPollingClient;
 
 @Sharable
 public class EncoderHandler extends ChannelOutboundHandlerAdapter {
 
-    private static final AttributeKey<Boolean> WRITE_ONCE = AttributeKey.<Boolean>valueOf("writeOnce");
-
     private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final Encoder encoder;
@@ -70,7 +69,7 @@ public class EncoderHandler extends ChannelOutboundHandlerAdapter {
 
     private void write(XHRSendPacketsMessage msg, ChannelHandlerContext ctx, ByteBuf out) throws IOException {
         Channel channel = ctx.channel();
-        Attribute<Boolean> attr = channel.attr(WRITE_ONCE);
+        Attribute<Boolean> attr = channel.attr(XHRPollingClient.WRITE_ONCE);
 
         if (!channel.isActive()
                 || msg.getPacketQueue().isEmpty()

src/main/java/com/corundumstudio/socketio/transport/XHRPollingClient.java

@@ -17,6 +17,7 @@ package com.corundumstudio.socketio.transport;
 
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
+import io.netty.util.AttributeKey;
 
 import java.util.Queue;
 import java.util.UUID;
@@ -31,6 +32,8 @@ import com.corundumstudio.socketio.parser.Packet;
 
 public class XHRPollingClient extends MainBaseClient {
 
+    public static final AttributeKey<Boolean> WRITE_ONCE = AttributeKey.<Boolean>valueOf("writeOnce");
+
     private final Queue<Packet> packetQueue = new ConcurrentLinkedQueue<Packet>();
     private String origin;
 
@@ -48,9 +51,12 @@ public class XHRPollingClient extends MainBaseClient {
         return origin;
     }
 
-    public ChannelFuture send(final Packet packet) {
+    public ChannelFuture send(Packet packet) {
         packetQueue.add(packet);
-        return getChannel().write(new XHRSendPacketsMessage(getSessionId(), origin, packetQueue));
+        if (getChannel().attr(WRITE_ONCE).get() == null) {
+            return getChannel().write(new XHRSendPacketsMessage(getSessionId(), origin, packetQueue));
+        }
+        return getChannel().newSucceededFuture();
     }
 
 }