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 com.google.common.base.Joiner;
  import com.google.common.collect.ImmutableList;
  import com.google.protobuf.ByteString;
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.util.Arrays;
  import java.util.List;
  import org.apache.arrow.flight.impl.Flight;
  import org.apache.arrow.flight.impl.Flight.FlightDescriptor.DescriptorType;
  import org.apache.arrow.util.Preconditions;
  
  /**
   * An identifier for a particular set of data. This can either be an opaque command that generates
   * the data or a static "path" to the data. This is a POJO wrapper around the protobuf message with
   * the same name.
   */
  public class FlightDescriptor {
  
    private boolean isCmd;
    private List<String> path;
    private byte[] cmd;
  
    private FlightDescriptor(boolean isCmd, List<String> path, byte[] cmd) {
      super();
      this.isCmd = isCmd;
      this.path = path;
      this.cmd = cmd;
    }
  
    public static FlightDescriptor command(byte[] cmd) {
      return new FlightDescriptor(true, null, cmd);
    }
  
    public static FlightDescriptor path(Iterable<String> path) {
      return new FlightDescriptor(false, ImmutableList.copyOf(path), null);
    }
  
    public static FlightDescriptor path(String... path) {
      return new FlightDescriptor(false, ImmutableList.copyOf(path), null);
    }
  
    FlightDescriptor(Flight.FlightDescriptor descriptor) {
      if (descriptor.getType() == DescriptorType.CMD) {
        isCmd = true;
        cmd = descriptor.getCmd().toByteArray();
      } else if (descriptor.getType() == DescriptorType.PATH) {
        isCmd = false;
        path = descriptor.getPathList();
      } else {
        throw new UnsupportedOperationException();
      }
    }
  
    public boolean isCommand() {
      return isCmd;
    }
  
    public List<String> getPath() {
      Preconditions.checkArgument(!isCmd);
      return path;
    }
  
    public byte[] getCommand() {
      Preconditions.checkArgument(isCmd);
      return cmd;
    }
  
    Flight.FlightDescriptor toProtocol() {
      Flight.FlightDescriptor.Builder b = Flight.FlightDescriptor.newBuilder();
  
      if (isCmd) {
        return b.setType(DescriptorType.CMD).setCmd(ByteString.copyFrom(cmd)).build();
      }
      return b.setType(DescriptorType.PATH).addAllPath(path).build();
    }
  
    /**
     * Get the serialized form of this protocol message.
     *
     * <p>Intended to help interoperability by allowing non-Flight services to still return Flight
     * types.
     */
    public ByteBuffer serialize() {
      return ByteBuffer.wrap(toProtocol().toByteArray());
    }
  
    /**
     * Parse the serialized form of this protocol message.
     *
     * <p>Intended to help interoperability by allowing Flight clients to obtain stream info from
     * non-Flight services.
     *
     * @param serialized The serialized form of the FlightDescriptor, as returned by {@link
     *     #serialize()}.
     * @return The deserialized FlightDescriptor.
     * @throws IOException if the serialized form is invalid.
     */
    public static FlightDescriptor deserialize(ByteBuffer serialized) throws IOException {
      return new FlightDescriptor(Flight.FlightDescriptor.parseFrom(serialized));
    }
  
    @Override
    public String toString() {
      if (isCmd) {
        return toHex(cmd);
      } else {
        return Joiner.on('.').join(path);
      }
    }
  
    private String toHex(byte[] bytes) {
      StringBuilder sb = new StringBuilder();
      for (byte b : bytes) {
        sb.append(String.format("%02X ", b));
      }
      return sb.toString();
    }
  
    @Override
    public int hashCode() {
      final int prime = 31;
      int result = 1;
      result = prime * result + ((cmd == null) ? 0 : Arrays.hashCode(cmd));
      result = prime * result + (isCmd ? 1231 : 1237);
      result = prime * result + ((path == null) ? 0 : path.hashCode());
      return result;
    }
  
    @Override
    public boolean equals(Object obj) {
      if (this == obj) {
        return true;
      }
      if (obj == null) {
        return false;
      }
      if (!(obj instanceof FlightDescriptor)) {
        return false;
      }
      FlightDescriptor other = (FlightDescriptor) obj;
      if (cmd == null) {
        if (other.cmd != null) {
          return false;
        }
      } else if (!Arrays.equals(cmd, other.cmd)) {
        return false;
      }
      if (isCmd != other.isCmd) {
        return false;
      }
      if (path == null) {
        if (other.path != null) {
          return false;
        }
      } else if (!path.equals(other.path)) {
        return false;
      }
      return true;
    }
  }
  