content: /*
   * 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.arrow.flight.grpc;
  
  import io.grpc.Context;
  import java.util.HashMap;
  import java.util.Set;
  import org.apache.arrow.flight.RequestContext;
  
  /** Adapter for holding key value pairs. */
  public class RequestContextAdapter implements RequestContext {
    public static final Context.Key<RequestContext> REQUEST_CONTEXT_KEY =
        Context.key("arrow-flight-request-context");
    private final HashMap<String, String> map = new HashMap<>();
  
    @Override
    public void put(String key, String value) {
      if (map.putIfAbsent(key, value) != null) {
        throw new IllegalArgumentException(
            "Duplicate write to a RequestContext at key " + key + " not allowed.");
      }
    }
  
    @Override
    public String get(String key) {
      return map.get(key);
    }
  
    @Override
    public Set<String> keySet() {
      return map.keySet();
    }
  
    @Override
    public String remove(String key) {
      return map.remove(key);
    }
  }
  