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.common.grpc.stats;
  
  import io.grpc.ForwardingServerCallListener;
  import io.grpc.ServerCall.Listener;
  
  /**
   * A {@link ForwardingServerCallListener} that monitors stats on grpc clients.
   */
  class MonitoringServerCallListener<RespT> extends ForwardingServerCallListener<RespT> {
  
      private final Listener<RespT> delegate;
      private final ServerStats stats;
  
      MonitoringServerCallListener(Listener<RespT> delegate,
                                   ServerStats stats) {
          this.delegate = delegate;
          this.stats = stats;
      }
  
      @Override
      protected Listener<RespT> delegate() {
          return delegate;
      }
  
      @Override
      public void onMessage(RespT message) {
          stats.recordStreamMessageReceived();
          super.onMessage(message);
      }
  
      @Override
      public String toString() {
          return delegate.toString();
      }
  }
  