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.exporter.provider.kafka.trace;
  
  import com.google.protobuf.InvalidProtocolBufferException;
  import java.util.List;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.kafka.clients.producer.ProducerRecord;
  import org.apache.kafka.common.utils.Bytes;
  import org.apache.skywalking.apm.network.language.agent.v3.SegmentObject;
  import org.apache.skywalking.apm.network.language.agent.v3.SpanObject;
  import org.apache.skywalking.oap.server.core.UnexpectedException;
  import org.apache.skywalking.oap.server.core.analysis.manual.segment.SegmentRecord;
  import org.apache.skywalking.oap.server.core.exporter.TraceExportService;
  import org.apache.skywalking.oap.server.exporter.provider.ExporterSetting;
  import org.apache.skywalking.oap.server.exporter.provider.kafka.KafkaExportProducer;
  import org.apache.skywalking.oap.server.library.datacarrier.DataCarrier;
  import org.apache.skywalking.oap.server.library.datacarrier.buffer.BufferStrategy;
  import org.apache.skywalking.oap.server.library.datacarrier.consumer.IConsumer;
  import org.apache.skywalking.oap.server.library.module.ModuleManager;
  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.MetricsCreator;
  import org.apache.skywalking.oap.server.telemetry.api.MetricsTag;
  
  @Slf4j
  public class KafkaTraceExporter extends KafkaExportProducer implements TraceExportService, IConsumer<SegmentRecord> {
      private DataCarrier<SegmentRecord> exportBuffer;
      private CounterMetrics successCounter;
      private CounterMetrics errorCounter;
      private final ModuleManager moduleManager;
  
      public KafkaTraceExporter(ModuleManager manager, ExporterSetting setting) {
          super(setting);
          this.moduleManager = manager;
      }
  
      @Override
      public void start() {
          super.getProducer();
          exportBuffer = new DataCarrier<>(
              "KafkaTraceExporter", "KafkaTraceExporter", setting.getBufferChannelNum(), setting.getBufferChannelSize(),
              BufferStrategy.IF_POSSIBLE
          );
          exportBuffer.consume(this, 1, 200);
          MetricsCreator metricsCreator = moduleManager.find(TelemetryModule.NAME)
                                                       .provider()
                                                       .getService(MetricsCreator.class);
          successCounter = metricsCreator.createCounter(
              "kafka_exporter_trace_success_count", "The success number of traces exported by kafka exporter.",
              new MetricsTag.Keys("protocol"),
              new MetricsTag.Values("kafka")
          );
          errorCounter = metricsCreator.createCounter(
              "kafka_exporter_trace_error_count", "The error number of traces exported by kafka exporter",
              new MetricsTag.Keys("protocol"), new MetricsTag.Values("kafka")
          );
      }
  
      public void export(SegmentRecord segmentRecord) {
          if (segmentRecord != null) {
              exportBuffer.produce(segmentRecord);
          }
  
      }
  
      @Override
      public boolean isEnabled() {
          return setting.isEnableKafkaTrace();
      }
  
      @Override
      public void consume(final List<SegmentRecord> data) {
          for (SegmentRecord segmentRecord : data) {
              if (segmentRecord != null) {
                  try {
                      SegmentObject segmentObject = SegmentObject.parseFrom(segmentRecord.getDataBinary());
                      if (setting.isExportErrorStatusTraceOnly() && !isError(segmentObject)) {
                          continue;
                      }
                      ProducerRecord<String, Bytes> record = new ProducerRecord<>(
                          setting.getKafkaTopicTrace(),
                          segmentObject.getTraceSegmentId(),
                          Bytes.wrap(segmentObject.toByteArray())
                      );
                      super.getProducer().send(record, (metadata, ex) -> {
                          if (ex != null) {
                              errorCounter.inc();
                              log.error("Failed to export Trace.", ex);
                          } else {
                              successCounter.inc();
                          }
                      });
                  } catch (InvalidProtocolBufferException e) {
                      throw new UnexpectedException(
                          "Failed to parse SegmentObject from SegmentRecord, id: " + segmentRecord.getSegmentId() + ".", e
                      );
                  }
              }
          }
      }
  
      private boolean isError(SegmentObject segmentObject) {
          for (SpanObject spanObject : segmentObject.getSpansList()) {
              if (spanObject.getIsError()) {
                  return true;
              }
          }
          return false;
      }
  
      @Override
      public void onError(final List<SegmentRecord> data, final Throwable t) {
  
      }
  }
  