content: /*
   * Copyright (c) 2019 abc123lzf <abc123lzf@126.com>
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  package com.lzf.flyingsocks.misc;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.Unpooled;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.ChannelOutboundHandlerAdapter;
  import io.netty.channel.ChannelPromise;
  
  import java.util.Arrays;
  import java.util.Objects;
  
  /**
   * 在发送消息时自动添加分隔符
   *
   * @author lzf abc123lzf@126.com
   * @since 2021/1/23 23:14
   */
  public class DelimiterOutboundHandler extends ChannelOutboundHandlerAdapter {
  
      /**
       * 分隔符ByteBuf
       */
      private final ByteBuf delimiter;
  
      /**
       * 强制使用VoidPromise
       */
      private final boolean enforceVoidPromise;
  
  
      public DelimiterOutboundHandler(byte[] delimiter) {
          this(delimiter, false);
      }
  
  
      public DelimiterOutboundHandler(byte[] delimiter, boolean enforceVoidPromise) {
          Objects.requireNonNull(delimiter);
          byte[] arr = Arrays.copyOf(delimiter, delimiter.length);
          this.delimiter = Unpooled.wrappedBuffer(arr).asReadOnly();
          this.enforceVoidPromise = enforceVoidPromise;
      }
  
  
      @Override
      public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
          if (msg instanceof ByteBuf) {
              delimiter.readerIndex(0);
              if (enforceVoidPromise) {
                  promise = ctx.voidPromise();
              }
              ctx.write(msg, promise);
              ctx.write(delimiter.retain(), promise);
          } else {
              ctx.write(msg, promise);
          }
      }
  }
  