content: /*
   * 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.bookkeeper.clients.impl.container;
  
  import static org.apache.bookkeeper.stream.protocol.ProtocolConstants.SC_ID_KEY;
  
  import io.grpc.CallOptions;
  import io.grpc.Channel;
  import io.grpc.ClientCall;
  import io.grpc.ClientInterceptor;
  import io.grpc.ClientInterceptors.CheckedForwardingClientCall;
  import io.grpc.Metadata;
  import io.grpc.MethodDescriptor;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.bookkeeper.common.grpc.netty.LongBinaryMarshaller;
  
  /**
   * A client interceptor that intercepting outgoing calls to storage containers.
   */
  @Slf4j
  public class StorageContainerClientInterceptor implements ClientInterceptor {
  
      private final long scId;
      private final Metadata.Key<Long> scIdKey;
  
      public StorageContainerClientInterceptor(long scId) {
          this.scId = scId;
          this.scIdKey = Metadata.Key.of(
              SC_ID_KEY,
              LongBinaryMarshaller.of());
      }
  
      @Override
      public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(MethodDescriptor<ReqT, RespT> method,
                                                                 CallOptions callOptions,
                                                                 Channel next) {
          if (log.isTraceEnabled()) {
              log.trace("Intercepting method {} : req marshaller = {}, resp marshaller = {}",
                  method.getFullMethodName(),
                  method.getRequestMarshaller(),
                  method.getResponseMarshaller());
          }
          return new CheckedForwardingClientCall<ReqT, RespT>(next.newCall(method, callOptions)) {
              @Override
              protected void checkedStart(Listener<RespT> responseListener,
                                          Metadata headers) throws Exception {
                  if (log.isTraceEnabled()) {
                      log.trace("Attaching storage container {},", scId);
                  }
                  headers.put(scIdKey, scId);
                  delegate().start(responseListener, headers);
              }
  
              @Override
              public void request(int numMessages) {
                  if (log.isTraceEnabled()) {
                      log.trace("request {} messages", numMessages);
                  }
                  super.request(numMessages);
              }
          };
      }
  }
  