code: /*
   * 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.skywalking.oap.server.receiver.meter.provider.handler;
  
  import io.grpc.Status;
  import io.grpc.stub.StreamObserver;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.skywalking.apm.network.common.v3.Commands;
  import org.apache.skywalking.apm.network.language.agent.v3.MeterData;
  import org.apache.skywalking.apm.network.language.agent.v3.MeterDataCollection;
  import org.apache.skywalking.apm.network.language.agent.v3.MeterReportServiceGrpc;
  import org.apache.skywalking.oap.server.analyzer.provider.meter.process.IMeterProcessService;
  import org.apache.skywalking.oap.server.analyzer.provider.meter.process.MeterProcessor;
  import org.apache.skywalking.oap.server.library.module.ModuleManager;
  import org.apache.skywalking.oap.server.library.server.grpc.GRPCHandler;
  import org.apache.skywalking.oap.server.telemetry.TelemetryModule;
  import org.apache.skywalking.oap.server.telemetry.api.CounterMetrics;
  import org.apache.skywalking.oap.server.telemetry.api.HistogramMetrics;
  import org.apache.skywalking.oap.server.telemetry.api.MetricsCreator;
  import org.apache.skywalking.oap.server.telemetry.api.MetricsTag;
  
  /**
   * Meter protocol receiver, collect and process the meters.
   */
  @Slf4j
  public class MeterServiceHandler extends MeterReportServiceGrpc.MeterReportServiceImplBase implements GRPCHandler {
  
      private final IMeterProcessService processService;
      private final HistogramMetrics histogram;
      private final CounterMetrics errorCounter;
  
      public MeterServiceHandler(ModuleManager manager, IMeterProcessService processService) {
          this.processService = processService;
          MetricsCreator metricsCreator = manager.find(TelemetryModule.NAME)
                  .provider()
                  .getService(MetricsCreator.class);
          histogram = metricsCreator.createHistogramMetric(
                  "meter_in_latency", "The process latency of meter",
                  new MetricsTag.Keys("protocol"), new MetricsTag.Values("grpc")
          );
          errorCounter = metricsCreator.createCounter("meter_analysis_error_count", "The error number of meter analysis",
                  new MetricsTag.Keys("protocol"),
                  new MetricsTag.Values("grpc")
          );
      }
  
      @Override
      public StreamObserver<MeterData> collect(StreamObserver<Commands> responseObserver) {
          final MeterProcessor processor = processService.createProcessor();
          return new StreamObserver<MeterData>() {
              @Override
              public void onNext(MeterData meterData) {
                  try (HistogramMetrics.Timer ignored = histogram.createTimer()) {
                      processor.read(meterData);
                  } catch (Exception e) {
                      errorCounter.inc();
                      log.error(e.getMessage(), e);
                  }
              }
  
              @Override
              public void onError(Throwable throwable) {
                  processor.process();
                  Status status = Status.fromThrowable(throwable);
                  if (Status.CANCELLED.getCode() == status.getCode()) {
                      if (log.isDebugEnabled()) {
                          log.debug(throwable.getMessage(), throwable);
                      }
                      return;
                  }
                  log.error(throwable.getMessage(), throwable);
              }
  
              @Override
              public void onCompleted() {
                  processor.process();
                  responseObserver.onNext(Commands.newBuilder().build());
                  responseObserver.onCompleted();
              }
          };
      }
  
      @Override
      public StreamObserver<MeterDataCollection> collectBatch(StreamObserver<Commands> responseObserver) {
          return new StreamObserver<MeterDataCollection>() {
              @Override
              public void onNext(MeterDataCollection meterDataCollection) {
                  final MeterProcessor processor = processService.createProcessor();
                  try (HistogramMetrics.Timer ignored = histogram.createTimer()) {
                      meterDataCollection.getMeterDataList().forEach(processor::read);
                      processor.process();
                  } catch (Exception e) {
                      errorCounter.inc();
                      log.error(e.getMessage(), e);
                  }
              }
  
              @Override
              public void onError(Throwable throwable) {
                  Status status = Status.fromThrowable(throwable);
                  if (Status.CANCELLED.getCode() == status.getCode()) {
                      if (log.isDebugEnabled()) {
                          log.debug(throwable.getMessage(), throwable);
                      }
                      return;
                  }
                  log.error(throwable.getMessage(), throwable);
              }
  
              @Override
              public void onCompleted() {
                  responseObserver.onNext(Commands.newBuilder().build());
                  responseObserver.onCompleted();
              }
          };
      }
  }
  