content: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.alibaba.wasp.ipc;
  
  import java.io.IOException;
  
  /**
   * Superclass of all protocols that use Hadoop RPC. Subclasses of this interface
   * are also supposed to have a static final long versionID field.
   */
  public interface VersionedProtocol {
  
    /**
     * Return protocol version corresponding to protocol interface.
     * 
     * @param protocol
     *          The classname of the protocol interface
     * @param clientVersion
     *          The version of the protocol that the client speaks
     * @return the version that the server will speak
     * @throws java.io.IOException
     *           if any IO error occurs
     */
    public long getProtocolVersion(String protocol, long clientVersion)
        throws IOException;
  }
  