content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.grpc;
  
  import alluxio.RuntimeConstants;
  
  import io.grpc.CallOptions;
  import io.grpc.Channel;
  import io.grpc.ClientCall;
  import io.grpc.ClientInterceptor;
  import io.grpc.ForwardingClientCall;
  import io.grpc.ForwardingClientCallListener;
  import io.grpc.Metadata;
  import io.grpc.MethodDescriptor;
  
  /**
   * Client side interceptor that is used to set the request header for the client version.
   */
  public class ClientVersionClientInjector implements ClientInterceptor {
    public static final Metadata.Key<String> S_CLIENT_VERSION_KEY =
        Metadata.Key.of("alluxio-version", Metadata.ASCII_STRING_MARSHALLER);
  
    @Override
    public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(MethodDescriptor<ReqT, RespT> method,
        CallOptions callOptions, Channel next) {
      return new ForwardingClientCall.SimpleForwardingClientCall<ReqT, RespT>(
          next.newCall(method, callOptions)) {
        @Override
        public void start(Listener<RespT> responseListener, Metadata headers) {
          // Put version to headers.
          headers.put(S_CLIENT_VERSION_KEY, RuntimeConstants.VERSION_AND_REVISION_SHORT);
          super.start(new ForwardingClientCallListener.SimpleForwardingClientCallListener<RespT>(
              responseListener) {
            @Override
            public void onHeaders(Metadata headers) {
              super.onHeaders(headers);
            }
          }, headers);
        }
      };
    }
  }
  