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;
  
  import io.grpc.Metadata;
  import io.grpc.stub.AbstractStub;
  import io.grpc.stub.MetadataUtils;
  
  /** Method option for supplying headers to method calls. */
  public class HeaderCallOption implements CallOptions.GrpcCallOption {
    private final Metadata propertiesMetadata = new Metadata();
  
    /**
     * Header property constructor.
     *
     * @param headers the headers that should be sent across. If a header is a string, it should only
     *     be valid ASCII characters. Binary headers should end in "-bin".
     */
    public HeaderCallOption(CallHeaders headers) {
      for (String key : headers.keys()) {
        if (key.endsWith(Metadata.BINARY_HEADER_SUFFIX)) {
          final Metadata.Key<byte[]> metaKey = Metadata.Key.of(key, Metadata.BINARY_BYTE_MARSHALLER);
          headers.getAllByte(key).forEach(v -> propertiesMetadata.put(metaKey, v));
        } else {
          final Metadata.Key<String> metaKey = Metadata.Key.of(key, Metadata.ASCII_STRING_MARSHALLER);
          headers.getAll(key).forEach(v -> propertiesMetadata.put(metaKey, v));
        }
      }
    }
  
    @Override
    public <T extends AbstractStub<T>> T wrapStub(T stub) {
      return stub.withInterceptors(MetadataUtils.newAttachHeadersInterceptor(propertiesMetadata));
    }
  }
  