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.zipkin.handler;
  
  import com.linecorp.armeria.common.HttpData;
  import com.linecorp.armeria.common.HttpRequest;
  import com.linecorp.armeria.common.HttpResponse;
  import com.linecorp.armeria.common.HttpStatus;
  import com.linecorp.armeria.server.annotation.ConsumesJson;
  import com.linecorp.armeria.server.annotation.ConsumesProtobuf;
  import com.linecorp.armeria.server.annotation.Post;
  import java.util.List;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.skywalking.oap.server.library.module.ModuleManager;
  import org.apache.skywalking.oap.server.receiver.zipkin.ZipkinReceiverConfig;
  import org.apache.skywalking.oap.server.receiver.zipkin.trace.SpanForward;
  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;
  import zipkin2.Span;
  import zipkin2.codec.SpanBytesDecoder;
  
  import static java.util.Objects.nonNull;
  
  @Slf4j
  public class ZipkinSpanHTTPHandler {
      private final HistogramMetrics histogram;
      private final CounterMetrics errorCounter;
      private final SpanForward spanForward;
  
      public ZipkinSpanHTTPHandler(ZipkinReceiverConfig config, ModuleManager manager) {
          this.spanForward = new SpanForward(config, manager);
          MetricsCreator metricsCreator = manager.find(TelemetryModule.NAME)
                                                 .provider()
                                                 .getService(MetricsCreator.class);
          histogram = metricsCreator.createHistogramMetric(
              "trace_in_latency", "The process latency of trace data",
              new MetricsTag.Keys("protocol"), new MetricsTag.Values("zipkin-http")
          );
          errorCounter = metricsCreator.createCounter(
              "trace_analysis_error_count", "The error number of trace analysis",
              new MetricsTag.Keys("protocol"), new MetricsTag.Values("zipkin-http")
          );
      }
  
      @Post("/api/v2/spans")
      public HttpResponse collectV2Spans(HttpRequest req) {
          return doCollectSpans(SpanBytesDecoder.JSON_V2, req);
      }
  
      @Post("/api/v2/spans")
      @ConsumesJson
      public HttpResponse collectV2JsonSpans(HttpRequest req) {
          return doCollectSpans(SpanBytesDecoder.JSON_V2, req);
      }
  
      @Post("/api/v2/spans")
      @ConsumesProtobuf
      public HttpResponse collectV2ProtobufSpans(HttpRequest req) {
          return doCollectSpans(SpanBytesDecoder.PROTO3, req);
      }
  
      @Post("/api/v1/spans")
      public HttpResponse collectV1Spans(HttpRequest req) {
          return doCollectSpans(SpanBytesDecoder.JSON_V1, req);
      }
  
      @Post("/api/v1/spans")
      @ConsumesJson
      public HttpResponse collectV1JsonSpans(HttpRequest req) {
          return doCollectSpans(SpanBytesDecoder.JSON_V1, req);
      }
  
      @Post("/api/v1/spans")
      @ConsumesThrift
      public HttpResponse collectV1ThriftSpans(HttpRequest req) {
          return doCollectSpans(SpanBytesDecoder.THRIFT, req);
      }
  
      HttpResponse doCollectSpans(final SpanBytesDecoder decoder,
                                  final HttpRequest req) {
          final HistogramMetrics.Timer timer = histogram.createTimer();
          final HttpResponse response = HttpResponse.from(req.aggregate().thenApply(request -> {
              try (final HttpData httpData = request.content()) {
                  final List<Span> spanList = decoder.decodeList(httpData.byteBuf().nioBuffer());
                  spanForward.send(spanList);
                  return HttpResponse.of(HttpStatus.OK);
              }
          }));
          response.whenComplete().handle((unused, throwable) -> {
              if (nonNull(throwable)) {
                  errorCounter.inc();
              }
              timer.close();
              return null;
          });
          return response;
      }
  }
  