private static byte[] Pack(DanmuType action, byte[] payload)
{
byte[] packet;
if (payload == null)
{
payload = Array.Empty <byte>();
}
packet = new byte[payload.Length + 16];
using (MemoryStream stream = new MemoryStream(packet)) {
stream.Write(BitConverter.GetBytes(IPAddress.HostToNetworkOrder(packet.Length)), 0, 4);
// packet length
stream.Write(BitConverter.GetBytes(IPAddress.HostToNetworkOrder((short)16)), 0, 2);
// header length
stream.Write(BitConverter.GetBytes(IPAddress.HostToNetworkOrder((short)1)), 0, 2);
// version
stream.Write(BitConverter.GetBytes(IPAddress.HostToNetworkOrder((int)action)), 0, 4);
// action
stream.Write(BitConverter.GetBytes(IPAddress.HostToNetworkOrder(1)), 0, 4);
// magic
if (payload.Length > 0)
{
stream.Write(payload, 0, payload.Length);
}
// payload
}
return(packet);
}
/// <summary>
/// 构造器
/// </summary>
/// <param name="type"></param>
/// <param name="data"></param>
public Danmu(DanmuType type, byte[] data)
{
if (data == null)
{
throw new ArgumentNullException(nameof(data));
}
_type = type;
_data = data;
}
private static Danmu ResolveDanmuPayload(DanmuType action, byte[] payload)
{
switch (action)
{
case DanmuType.Command:
case DanmuType.Handshaking:
return(new Danmu(action, payload));
default:
return(Danmu.Empty);
}
}
/// <summary>
/// 解析弹幕
/// </summary>
/// <param name="action"></param>
/// <param name="payload">原始的二进制格式弹幕</param>
/// <returns></returns>
public static Danmu ResolveDanmu(DanmuType action, byte[] payload)
{
if (payload == null)
{
throw new ArgumentNullException(nameof(payload));
}
switch (action)
{
case DanmuType.Command:
case DanmuType.Handshaking:
return(new Danmu(action, payload));
default:
return(Danmu.Empty);
}
}
private static unsafe void ResolveDanmuHeader(byte[] header, out int length, out DanmuType action)
{
fixed(byte *p = header)
{
int value;
value = IPAddress.NetworkToHostOrder(*(int *)p);
// packet length
length = value - 16;
#pragma warning disable IDE0059
value = IPAddress.NetworkToHostOrder(*(short *)(p + 4));
// header length
value = IPAddress.NetworkToHostOrder(*(short *)(p + 6));
// version
value = IPAddress.NetworkToHostOrder(*(int *)(p + 8));
// action
action = (DanmuType)value;
value = IPAddress.NetworkToHostOrder(*(int *)(p + 12));
// magic
#pragma warning restore IDE0059
}
}
private static byte[] Pack(DanmuType action, string payload)
{
return(Pack(action, payload == null ? null : Encoding.UTF8.GetBytes(payload)));
}
