001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.ipc;
019
020import io.opentelemetry.context.Context;
021import io.opentelemetry.context.propagation.TextMapGetter;
022import java.util.Collections;
023import java.util.Map;
024import java.util.Optional;
025import org.apache.yetus.audience.InterfaceAudience;
026
027import org.apache.hadoop.hbase.shaded.protobuf.generated.TracingProtos;
028
029/**
030 * Used to extract a tracing {@link Context} from an instance of {@link TracingProtos.RPCTInfo}.
031 */
032@InterfaceAudience.Private
033final class RPCTInfoGetter implements TextMapGetter<TracingProtos.RPCTInfo> {
034  RPCTInfoGetter() {
035  }
036
037  @Override
038  public Iterable<String> keys(TracingProtos.RPCTInfo carrier) {
039    return Optional.ofNullable(carrier).map(TracingProtos.RPCTInfo::getHeadersMap).map(Map::keySet)
040      .orElse(Collections.emptySet());
041  }
042
043  @Override
044  public String get(TracingProtos.RPCTInfo carrier, String key) {
045    return Optional.ofNullable(carrier).map(TracingProtos.RPCTInfo::getHeadersMap)
046      .map(map -> map.get(key)).orElse(null);
047  }
048}