code: /*
   * Copyright (c) 2019 the Eclipse Milo Authors
   *
   * This program and the accompanying materials are made
   * available under the terms of the Eclipse Public License 2.0
   * which is available at https://www.eclipse.org/legal/epl-2.0/
   *
   * SPDX-License-Identifier: EPL-2.0
   */
  
  package org.eclipse.milo.opcua.stack.core.channel.messages;
  
  import io.netty.buffer.ByteBuf;
  import org.eclipse.milo.opcua.stack.core.UaException;
  
  public class TcpMessageDecoder {
  
      public static HelloMessage decodeHello(ByteBuf buffer) throws UaException {
          MessageType messageType = MessageType.fromMediumInt(buffer.readMediumLE());
          char chunkType = (char) buffer.readByte();
          buffer.skipBytes(4); // length
  
          assert (messageType == MessageType.Hello && chunkType == 'F');
  
          return HelloMessage.decode(buffer);
      }
  
      public static AcknowledgeMessage decodeAcknowledge(ByteBuf buffer) throws UaException {
          MessageType messageType = MessageType.fromMediumInt(buffer.readMediumLE());
          char chunkType = (char) buffer.readByte();
          buffer.skipBytes(4); // length
  
          assert (messageType == MessageType.Acknowledge && chunkType == 'F');
  
          return AcknowledgeMessage.decode(buffer);
      }
  
      public static ErrorMessage decodeError(ByteBuf buffer) throws UaException {
          MessageType messageType = MessageType.fromMediumInt(buffer.readMediumLE());
          char chunkType = (char) buffer.readByte();
          buffer.skipBytes(4); // length
  
          assert (messageType == MessageType.Error && chunkType == 'F');
  
          return ErrorMessage.decode(buffer);
      }
  
  }
  