KeepAlivePacket.java

/*
 * This file is part of Waarp Project (named also Waarp or GG).
 *
 *  Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
 *  tags. See the COPYRIGHT.txt in the distribution for a full listing of
 * individual contributors.
 *
 *  All Waarp Project is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 *
 * Waarp is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with
 * Waarp . If not, see <http://www.gnu.org/licenses/>.
 */
package org.waarp.openr66.protocol.localhandler.packet;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.buffer.Unpooled;
import org.waarp.common.utility.WaarpNettyUtil;
import org.waarp.openr66.protocol.exception.OpenR66ProtocolPacketException;
import org.waarp.openr66.protocol.localhandler.LocalChannelReference;

/**
 * Keep Alive class
 * <p>
 * header = empty middle = way end = empty
 */
public class KeepAlivePacket extends AbstractLocalPacket {
  private static final byte ASKVALIDATE = 0;

  private static final byte ANSWERVALIDATE = 1;

  private byte way;

  /**
   * @param headerLength
   * @param middleLength
   * @param endLength
   * @param buf
   *
   * @return the new EndTransferPacket from buffer
   *
   * @throws OpenR66ProtocolPacketException
   */
  public static KeepAlivePacket createFromBuffer(final int headerLength,
                                                 final int middleLength,
                                                 final int endLength,
                                                 final ByteBuf buf)
      throws OpenR66ProtocolPacketException {
    if (middleLength != 1) {
      throw new OpenR66ProtocolPacketException("Not enough data");
    }
    final byte valid = buf.readByte();
    return new KeepAlivePacket(valid);
  }

  /**
   * @param valid
   */
  private KeepAlivePacket(final byte valid) {
    way = valid;
  }

  /**
   *
   */
  public KeepAlivePacket() {
    way = ASKVALIDATE;
  }

  @Override
  public final boolean hasGlobalBuffer() {
    return true;
  }

  @Override
  public final synchronized void createAllBuffers(
      final LocalChannelReference lcr, final int networkHeader) {
    final int globalSize = networkHeader + LOCAL_HEADER_SIZE + 1;
    final int offset = networkHeader + LOCAL_HEADER_SIZE;
    global = ByteBufAllocator.DEFAULT.ioBuffer(globalSize, globalSize);
    middle = WaarpNettyUtil.slice(global, offset, 1);
    middle.writeByte(way);
    end = Unpooled.EMPTY_BUFFER;
    header = Unpooled.EMPTY_BUFFER;
  }

  @Override
  public final byte getType() {
    return LocalPacketFactory.KEEPALIVEPACKET;
  }

  @Override
  public final String toString() {
    return "KeepAlivePacket: " + way;
  }

  /**
   * @return True if this packet is to be validated
   */
  public final boolean isToValidate() {
    return way == ASKVALIDATE;
  }

  /**
   * Validate the connection
   */
  public final void validate() {
    way = ANSWERVALIDATE;
    clear();
  }
}