hadoop ClientGSIContext 源码

haddop ClientGSIContext 代码

文件路径：/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/ClientGSIContext.java

/**
 * 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 org.apache.hadoop.hdfs;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.ipc.AlignmentContext;
import org.apache.hadoop.ipc.protobuf.RpcHeaderProtos.RpcRequestHeaderProto;
import org.apache.hadoop.ipc.protobuf.RpcHeaderProtos.RpcResponseHeaderProto;

import java.io.IOException;
import java.util.concurrent.atomic.LongAccumulator;
import org.apache.hadoop.thirdparty.protobuf.ByteString;

/**
 * Global State Id context for the client.
 * <p>
 * This is the client side implementation responsible for receiving
 * state alignment info from server(s).
 */
@InterfaceAudience.Private
@InterfaceStability.Evolving
public class ClientGSIContext implements AlignmentContext {

  private final LongAccumulator lastSeenStateId;
  private ByteString routerFederatedState;

  public ClientGSIContext() {
    this(new LongAccumulator(Math::max, Long.MIN_VALUE));
  }

  public ClientGSIContext(LongAccumulator lastSeenStateId) {
    this.lastSeenStateId = lastSeenStateId;
    routerFederatedState = null;
  }

  @Override
  public long getLastSeenStateId() {
    return lastSeenStateId.get();
  }

  @Override
  public boolean isCoordinatedCall(String protocolName, String method) {
    throw new UnsupportedOperationException(
        "Client should not be checking uncoordinated call");
  }

  /**
   * Client side implementation only receives state alignment info.
   * It does not provide state alignment info therefore this does nothing.
   */
  @Override
  public void updateResponseState(RpcResponseHeaderProto.Builder header) {
    // Do nothing.
  }

  /**
   * Client side implementation for receiving state alignment info
   * in responses.
   */
  @Override
  public synchronized void receiveResponseState(RpcResponseHeaderProto header) {
    if (header.hasRouterFederatedState()) {
      routerFederatedState = header.getRouterFederatedState();
    } else {
      lastSeenStateId.accumulate(header.getStateId());
    }
  }

  /**
   * Client side implementation for providing state alignment info in requests.
   */
  @Override
  public synchronized void updateRequestState(RpcRequestHeaderProto.Builder header) {
    if (lastSeenStateId.get() != Long.MIN_VALUE) {
      header.setStateId(lastSeenStateId.get());
    }
    if (routerFederatedState != null) {
      header.setRouterFederatedState(routerFederatedState);
    }
  }

  /**
   * Client side implementation only provides state alignment info in requests.
   * Client does not receive RPC requests therefore this does nothing.
   */
  @Override
  public long receiveRequestState(RpcRequestHeaderProto header, long threshold)
      throws IOException {
    // Do nothing.
    return 0;
  }
}

相关信息

hadoop 源码目录

相关文章

hadoop AddBlockFlag 源码

hadoop BlockMissingException 源码

hadoop BlockReader 源码

hadoop CannotObtainBlockLengthException 源码

hadoop ClientContext 源码

hadoop DFSClient 源码

hadoop DFSClientFaultInjector 源码

hadoop DFSHedgedReadMetrics 源码

hadoop DFSInotifyEventInputStream 源码

hadoop DFSInputStream 源码