content: /*
   * Copyright The OpenTelemetry Authors
   * SPDX-License-Identifier: Apache-2.0
   */
  
  package io.opentelemetry.javaagent.instrumentation.rabbitmq;
  
  import static java.util.Collections.emptySet;
  
  import com.rabbitmq.client.AMQP;
  import com.rabbitmq.client.GetResponse;
  import io.opentelemetry.context.propagation.TextMapGetter;
  import java.util.Map;
  import javax.annotation.Nullable;
  
  enum ReceiveRequestTextMapGetter implements TextMapGetter<ReceiveRequest> {
    INSTANCE;
  
    @Override
    public Iterable<String> keys(ReceiveRequest carrier) {
      Map<String, Object> headers = getHeaders(carrier);
      return headers == null ? emptySet() : headers.keySet();
    }
  
    @Nullable
    @Override
    public String get(@Nullable ReceiveRequest carrier, String key) {
      Map<String, Object> headers = getHeaders(carrier);
      if (headers == null) {
        return null;
      }
      Object value = headers.get(key);
      return value == null ? null : value.toString();
    }
  
    @Nullable
    private static Map<String, Object> getHeaders(@Nullable ReceiveRequest carrier) {
      if (carrier == null) {
        return null;
      }
      GetResponse response = carrier.getResponse();
      if (response == null) {
        return null;
      }
      AMQP.BasicProperties props = response.getProps();
      if (props == null) {
        return null;
      }
      return props.getHeaders();
    }
  }
  