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.otel.otlp;
  
  import io.grpc.stub.StreamObserver;
  import io.opentelemetry.proto.collector.metrics.v1.ExportMetricsServiceRequest;
  import io.opentelemetry.proto.collector.metrics.v1.ExportMetricsServiceResponse;
  import io.opentelemetry.proto.collector.metrics.v1.MetricsServiceGrpc;
  import lombok.RequiredArgsConstructor;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.skywalking.oap.server.core.server.GRPCHandlerRegister;
  import org.apache.skywalking.oap.server.library.module.ModuleManager;
  import org.apache.skywalking.oap.server.library.module.ModuleStartException;
  import org.apache.skywalking.oap.server.receiver.otel.Handler;
  import org.apache.skywalking.oap.server.receiver.sharing.server.SharingServerModule;
  
  @Slf4j
  @RequiredArgsConstructor
  public class OpenTelemetryMetricHandler
      extends MetricsServiceGrpc.MetricsServiceImplBase
      implements Handler {
      private final ModuleManager manager;
  
      private final OpenTelemetryMetricRequestProcessor metricRequestProcessor;
  
      @Override
      public String type() {
          return "otlp-metrics";
      }
  
      @Override
      public void active() throws ModuleStartException {
          GRPCHandlerRegister grpcHandlerRegister = manager.find(SharingServerModule.NAME)
                                                           .provider()
                                                           .getService(GRPCHandlerRegister.class);
          grpcHandlerRegister.addHandler(this);
      }
  
      @Override
      public void export(
          final ExportMetricsServiceRequest requests,
          final StreamObserver<ExportMetricsServiceResponse> responseObserver) {
          metricRequestProcessor.processMetricsRequest(requests);
          responseObserver.onNext(ExportMetricsServiceResponse.getDefaultInstance());
          responseObserver.onCompleted();
      }
  
  }
  