| /** |
| * 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; |
| |
| /** |
| * 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 = |
| new LongAccumulator(Math::max, Long.MIN_VALUE); |
| |
| @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 void receiveResponseState(RpcResponseHeaderProto header) { |
| lastSeenStateId.accumulate(header.getStateId()); |
| } |
| |
| /** |
| * Client side implementation for providing state alignment info in requests. |
| */ |
| @Override |
| public void updateRequestState(RpcRequestHeaderProto.Builder header) { |
| header.setStateId(lastSeenStateId.longValue()); |
| } |
| |
| /** |
| * 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; |
| } |
| } |