Add ability to disable default receive buffer size in websocket server

Signed-off-by: pwangryn <pawel.wangryn@icsec.pl>

src/main/java/org/java_websocket/AbstractWebSocket.java

@@ -102,6 +102,11 @@ public abstract class AbstractWebSocket extends WebSocketAdapter {
    */
   private final Object syncConnectionLost = new Object();
 
+  /**
+   * Attribute to disable default buffer size
+   */
+  private boolean disableReceiveBufferSize = false;
+
   /**
    * Get the interval checking for lost connections Default is 60 seconds
    *
@@ -336,4 +341,13 @@ public boolean isDaemon() {
   public void setDaemon(boolean daemon) {
     this.daemon = daemon;
   }
+
+  public boolean isReceiveBufferSizeDisabled() {
+    return disableReceiveBufferSize;
+  }
+
+  public void setDisableReceiveBufferSize(boolean disableReceiveBufferSize) {
+    this.disableReceiveBufferSize = disableReceiveBufferSize;
+  }
+
 }

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

@@ -578,7 +578,9 @@ private boolean doSetupSelectorAndServerThread() {
       server = ServerSocketChannel.open();
       server.configureBlocking(false);
       ServerSocket socket = server.socket();
-      socket.setReceiveBufferSize(WebSocketImpl.RCVBUF);
+      if (!isReceiveBufferSizeDisabled()) {
+        socket.setReceiveBufferSize(WebSocketImpl.RCVBUF);
+      }
       socket.setReuseAddress(isReuseAddr());
       socket.bind(address, getMaxPendingConnections());
       selector = Selector.open();