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.ForwardingServerCall.SimpleForwardingServerCall;
  import io.grpc.Metadata;
  import io.grpc.ServerCall;
  import io.grpc.Status;
  import org.apache.bookkeeper.common.util.MathUtils;
  
  /**
   * A {@link SimpleForwardingServerCall} which increments counters for rpc calls.
   */
  class MonitoringServerCall<ReqT, RespT> extends SimpleForwardingServerCall<ReqT, RespT> {
  
      private final ServerStats stats;
      private final long startNanos;
  
      MonitoringServerCall(ServerCall<ReqT, RespT> delegate,
                           ServerStats stats) {
          super(delegate);
          this.stats = stats;
          this.startNanos = MathUtils.nowInNano();
          stats.recordCallStarted();
      }
  
      @Override
      public void sendMessage(RespT message) {
          stats.recordStreamMessageSent();
          super.sendMessage(message);
      }
  
      @Override
      public void close(Status status, Metadata trailers) {
          stats.recordServerHandled(status.getCode());
          if (stats.shouldRecordLatency()) {
              long latencyMicros = MathUtils.elapsedMicroSec(startNanos);
              stats.recordLatency(Status.OK == status, latencyMicros);
          }
          super.close(status, trailers);
      }
  }
  