001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hdfs.server.namenode.ha;
019
020import java.io.Closeable;
021import java.io.IOException;
022import java.net.InetSocketAddress;
023import java.net.URI;
024
025import org.apache.hadoop.conf.Configuration;
026import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocols;
027import org.apache.hadoop.io.retry.FailoverProxyProvider;
028import org.apache.hadoop.ipc.RPC;
029import org.apache.hadoop.security.UserGroupInformation;
030
031import com.google.common.base.Preconditions;
032
033/**
034 * A NNFailoverProxyProvider implementation which wrapps old implementations
035 * directly implementing the {@link FailoverProxyProvider} interface.
036 *
037 * It is assumed that the old impelmentation is using logical URI.
038 */
039public class WrappedFailoverProxyProvider<T> extends
040    AbstractNNFailoverProxyProvider<T> {
041  private final FailoverProxyProvider<T> proxyProvider;
042  
043  /**
044   * Wrap the given instance of an old FailoverProxyProvider.
045   */
046  public WrappedFailoverProxyProvider(FailoverProxyProvider<T> provider) {
047    proxyProvider = provider;
048  }
049    
050  @Override
051  public Class<T> getInterface() {
052    return proxyProvider.getInterface();
053  }
054
055  @Override
056  public synchronized ProxyInfo<T> getProxy() {
057    return proxyProvider.getProxy();
058  }
059
060  @Override
061  public void performFailover(T currentProxy) {
062    proxyProvider.performFailover(currentProxy);
063  }
064
065  /**
066   * Close the proxy,
067   */
068  @Override
069  public synchronized void close() throws IOException {
070    proxyProvider.close();
071  }
072
073  /**
074   * Assume logical URI is used for old proxy provider implementations.
075   */
076  @Override
077  public boolean useLogicalURI() {
078    return true;
079  }
080}