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.event.grpc;
  
  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.event.v3.Event;
  import org.apache.skywalking.apm.network.event.v3.EventServiceGrpc;
  import org.apache.skywalking.oap.server.analyzer.event.EventAnalyzerModule;
  import org.apache.skywalking.oap.server.core.UnexpectedException;
  import org.apache.skywalking.oap.server.core.analysis.Layer;
  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.analyzer.event.EventAnalyzerService;
  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;
  
  @Slf4j
  public class EventGrpcServiceHandler extends EventServiceGrpc.EventServiceImplBase implements GRPCHandler {
      private final HistogramMetrics histogram;
  
      private final CounterMetrics errorCounter;
  
      private final EventAnalyzerService eventAnalyzerService;
  
      public EventGrpcServiceHandler(ModuleManager moduleManager) {
          final MetricsCreator metricsCreator = moduleManager.find(TelemetryModule.NAME)
                                                             .provider()
                                                             .getService(MetricsCreator.class);
  
          eventAnalyzerService = moduleManager.find(EventAnalyzerModule.NAME)
                                              .provider()
                                              .getService(EventAnalyzerService.class);
  
          histogram = metricsCreator.createHistogramMetric(
              "event_in_latency", "The process latency of event data",
              new MetricsTag.Keys("protocol"), new MetricsTag.Values("grpc")
          );
          errorCounter = metricsCreator.createCounter(
              "event_error_count", "The error number of event analysis",
              new MetricsTag.Keys("protocol"), new MetricsTag.Values("grpc")
          );
      }
  
      @Override
      public StreamObserver<Event> collect(StreamObserver<Commands> responseObserver) {
          return new StreamObserver<Event>() {
              @Override
              public void onNext(final Event event) {
                  try (HistogramMetrics.Timer ignored = histogram.createTimer()) {
                      String errMsg = null;
                      // Check event's layer
                      if (event.getLayer().isEmpty()) {
                          errMsg = "Layer field is required since v9.0.0, please upgrade your event report tools";
                      }
                      try {
                          Layer.nameOf(event.getLayer());
                      } catch (UnexpectedException e) {
                          errMsg = e.getMessage();
                      }
                      if (errMsg != null) {
                          responseObserver.onError(Status.INVALID_ARGUMENT.withDescription(errMsg).asException());
                          return;
                      }
  
                      eventAnalyzerService.analyze(event);
                  } 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();
              }
          };
      }
  }
  