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     */
018    package org.apache.hadoop.hdfs;
019    
020    import java.io.IOException;
021    import java.net.InetSocketAddress;
022    
023    import org.apache.hadoop.hdfs.net.Peer;
024    import org.apache.hadoop.hdfs.protocol.DatanodeID;
025    import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
026    import org.apache.hadoop.security.token.Token;
027    
028    public interface RemotePeerFactory {
029      /**
030       * @param addr          The address to connect to.
031       * @param blockToken    Token used during optional SASL negotiation
032       * @param datanodeId    ID of destination DataNode
033       * @return              A new Peer connected to the address.
034       *
035       * @throws IOException  If there was an error connecting or creating 
036       *                      the remote socket, encrypted stream, etc.
037       */
038      Peer newConnectedPeer(InetSocketAddress addr,
039          Token<BlockTokenIdentifier> blockToken, DatanodeID datanodeId)
040          throws IOException;
041    }