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.vector.ipc.message;
  
  import java.nio.ByteBuffer;
  import org.apache.arrow.flatbuf.Message;
  
  /**
   * Class to hold resulting Message metadata and buffer containing the serialized Flatbuffer message
   * when reading messages from a ReadChannel. This handles Message metadata only and does not include
   * the message body data, which should be subsequently read into an ArrowBuf.
   */
  public class MessageMetadataResult {
  
    /**
     * Construct a container to hold a deserialized Message metadata, and buffer with the serialized
     * Message as read from a ReadChannel.
     *
     * @param messageLength the length of the serialized Flatbuffer message in bytes
     * @param messageBuffer contains the serialized Flatbuffer Message metadata
     * @param message the deserialized Flatbuffer Message metadata description
     */
    MessageMetadataResult(int messageLength, ByteBuffer messageBuffer, Message message) {
      this.messageLength = messageLength;
      this.messageBuffer = messageBuffer;
      this.message = message;
    }
  
    /**
     * Creates a new {@link MessageMetadataResult} by parsing it from the beginning of the buffer.
     *
     * @param messageLength The length of the serialized flatbuffer message in bytes (might not be
     *     equal to the buffer size).
     */
    public static MessageMetadataResult create(ByteBuffer buffer, int messageLength) {
      return new MessageMetadataResult(messageLength, buffer, Message.getRootAsMessage(buffer));
    }
  
    /**
     * Get the length of the message metadata in bytes, not including the body length.
     *
     * @return number of bytes in the message metadata buffer.
     */
    public int getMessageLength() {
      return messageLength;
    }
  
    /**
     * Get the buffer containing the raw message metadata bytes, not including the message body data.
     *
     * @return buffer containing the message metadata.
     */
    public ByteBuffer getMessageBuffer() {
      return messageBuffer;
    }
  
    /** Returns the bytes remaining in the buffer after parsing the message from it. */
    public int bytesAfterMessage() {
      return message.getByteBuffer().remaining();
    }
  
    public byte headerType() {
      return message.headerType();
    }
  
    /**
     * Check if the message is followed by a body. This will be true if the message has a body length
     * > 0, which indicates that a message body needs to be read from the input source.
     *
     * @return true if message has a defined body
     */
    public boolean messageHasBody() {
      return message.bodyLength() > 0;
    }
  
    /**
     * Get the length of the message body.
     *
     * @return number of bytes of the message body
     */
    public long getMessageBodyLength() {
      return message.bodyLength();
    }
  
    /**
     * Get the realized flatbuf Message metadata description.
     *
     * @return Message metadata
     */
    public Message getMessage() {
      return message;
    }
  
    private final int messageLength;
    private final ByteBuffer messageBuffer;
    private final Message message;
  }
  