@Override
  public BoundedNettyByteBufReceive replace(ByteBuf content) {
    return new BoundedNettyByteBufReceive(content, sizeToRead, maxRequestSize);
  }
The total size in bytes that needs to receive from the channel
It will be initialized only after header is read.
@return the size of the data in bytes to receive after reading header, otherwise return 0
ambry-api/src/main/java/com/github/ambry/network/BoundedNettyByteBufReceive.java