/// <summary>
/// 生成发送给服务端的包
/// </summary>
/// <param name="compress">数据包压缩的阚值</param>
/// <exception cref="ArgumentOutOfRangeException"></exception>
/// <exception cref="IndexOutOfRangeException"></exception>
public virtual byte[] ToBytes(int compress = -1)
{
if (Empty)
{
throw new PacketException("Packet is empty");
}
byte[] PacketData;
if (compress > 0)
{
/*
* 压缩的数据包:
*
* 名称 类型 备注
* 数据包长度 Varint 等于下方两者解压前的总字节数
* 解压后长度 Varint 若为0则表示本包未被压缩
* 被压缩的数据 经Zlib压缩.开头是一个VarInt字段,代表数据包ID,然后是数据包数据.
*/
if (Data.Count >= compress)
{
//拼接PacketID(VarInt)和PacketData(ByteArray)并塞入ZlibUtils.Compress去压缩
byte[] uncompressed = new byte[Length];
Data.CopyTo(uncompressed, VarInt.WriteTo(ID, uncompressed));
byte[] compressed = ZlibUtils.Compress(uncompressed);
PacketData = new byte[VarInt.GetLength(VarInt.GetLength(uncompressed.Length) + compressed.Length) + VarInt.GetLength(uncompressed.Length) + compressed.Length];
//写入第一个VarInt(解压长度+压缩后的长度）
int offset = VarInt.WriteTo(VarInt.GetLength(uncompressed.Length) + compressed.Length, PacketData);
//写入第二个VarInt(未压缩长度)
offset += VarInt.WriteTo(uncompressed.Length, PacketData.AsSpan().Slice(offset));
//写入被压缩的数据
compressed.CopyTo(PacketData, offset);
}
else
{
PacketData = new byte[VarInt.GetLength(Length + 1) + Length + 1];
int offset = VarInt.WriteTo(Length + 1, PacketData);
PacketData[offset++] = 0;
offset += VarInt.WriteTo(ID, PacketData.AsSpan().Slice(offset));
if (Data.Count > 0)
{
Data.CopyTo(PacketData, offset);
}
}
}
else
{
PacketData = new byte[VarInt.GetLength(Length) + Length];
int offset = VarInt.WriteTo(Length, PacketData);
offset += VarInt.WriteTo(ID, PacketData.AsSpan().Slice(offset));
if (Data.Count > 0)
{
Data.CopyTo(PacketData, offset);
}
}
return(PacketData);
}
/// <summary>
/// 生成发送给服务端的包
/// </summary>
/// <param name="compress">数据包压缩的阚值</param>
/// <exception cref="ArgumentOutOfRangeException"></exception>
public virtual List <byte> ToList(int compress = -1)
{
if (Empty)
{
throw new PacketException("Packet is empty");
}
List <byte> PacketData = new List <byte>();
PacketData.Capacity = Length;
if (compress > 0)
{
if (Data.Count >= compress)
{
PacketData.AddRange(VarInt.GetBytes(Length));
int IdLength = VarInt.GetLength(ID);
byte[] buffer = new byte[IdLength + Data.Count];
Array.Copy(VarInt.GetBytes(ID), 0, buffer, 0, IdLength);
Data.CopyTo(buffer, IdLength);
PacketData.AddRange(ZlibUtils.Compress(buffer));
PacketData.InsertRange(0, VarInt.GetBytes(PacketData.Count));
}
else
{
PacketData.AddRange(VarInt.GetBytes(Length + 1));
PacketData.Add(0);
PacketData.AddRange(VarInt.GetBytes(ID));
PacketData.AddRange(Data);
}
}
else
{
PacketData.AddRange(VarInt.GetBytes(Length));
PacketData.AddRange(VarInt.GetBytes(ID));
PacketData.AddRange(Data);
}
return(PacketData);
}
