prevented unnecessary attempts to decode of empty buffers

Author: Davidiusdadi

src/main/java/org/java_websocket/server/WebSocketServer.java

@@ -326,16 +326,18 @@ public void run(){
 conn = (WebSocketImpl) key.attachment();
 ByteBufferbuf = takeBuffer();
 try{
-if( SocketChannelIOHelper.read( buf, conn, (ByteChannel) conn.channel ) ){
-assert ( buf.hasRemaining() );
-conn.inQueue.put( buf );
-queue( conn );
-i.remove();
-if( conn.channelinstanceofWrappedByteChannel ){
-if( ( (WrappedByteChannel) conn.channel ).isNeedRead() ){
-iqueue.add( conn );
+if( SocketChannelIOHelper.read( buf, conn, conn.channel ) ){
+if( buf.hasRemaining() ){
+conn.inQueue.put( buf );
+queue( conn );
+i.remove();
+if( conn.channelinstanceofWrappedByteChannel ){
+if( ( (WrappedByteChannel) conn.channel ).isNeedRead() ){
+iqueue.add( conn );
+ }
  }
- }
+ } else
+pushBuffer( buf );
  } else{
 pushBuffer( buf );
  }
@@ -346,7 +348,7 @@ public void run(){
  }
 if( key.isWritable() ){
 conn = (WebSocketImpl) key.attachment();
-if( SocketChannelIOHelper.batch( conn, (ByteChannel) conn.channel ) ){
+if( SocketChannelIOHelper.batch( conn, conn.channel ) ){
 if( key.isValid() )
 key.interestOps( SelectionKey.OP_READ );
  }
@@ -359,9 +361,12 @@ public void run(){
 try{
 if( SocketChannelIOHelper.readMore( buf, conn, c ) )
 iqueue.add( conn );
-assert ( buf.hasRemaining() );
-conn.inQueue.put( buf );
-queue( conn );
+if( buf.hasRemaining() ){
+conn.inQueue.put( buf );
+queue( conn );
+ } else{
+pushBuffer( buf );
+ }
  } catch ( IOExceptione ){
 pushBuffer( buf );
 throwe;