A C# BitField library.
这是一个在 C# 中的位域操作库，在没有原生语法糖加持的情况下，已经是非常舒服的写法了。
作者封装了用于实现位域的各种位移，且，或操作，使得在 C# 中也能灵活操作内存中的任意一个 bit。
位域操作可能是个比较小众的使用场景，欢迎大家互通有无。
Examples:
0x00. Demo (示例)
ABT bT = new ABT() { EA = A.Eghit | A.Two, EB = B.Three, IsBitFields = true };
// 是的,支持枚举, 甚至其他unmanaged数据
// 比如自定义的struct也是支持的(但内存布局需要紧凑模式:[StructLayout(LayoutKind.Sequential, Pack = 1)])
[Flags]
enum A : byte
{
Zero = 0,
One = 1 << 0,
Two = 1 << 1,
Four = 1 << 2,
Eghit = 1 << 3,
}
enum B : byte
{
One = 1,
Two = 2,
Three = 3,
}
// sizeof(ABT) = 1
struct ABT
{
private byte data;
public byte Data() => data;
public static implicit operator byte(ABT self) => self.data;
public static explicit operator ABT(byte mData) => new() { data = mData };
public bool IsBitFields
{
get => data.BitField<bool>(0, 1);
set => data.SetBitField(value, 0, 1);
}
public A EA
{
get => data.BitField<A>(1, 4);
set => data.SetBitField(value, 1, 4);
}
public B EB
{
get => data.BitField<B>(5, 2);
set => data.SetBitField(value, 5, 2);
}
}0x01. SnowFlake (分布式开发中的雪花ID算法)
class SnowFlake
{
static private long Ts() => DateTimeOffset.Now.ToUnixTimeMilliseconds(); // - 2015; if you like
public static SnowFlake NextId(int serialNum, int machineID)
=> new(sid: serialNum, mid: machineID);
private SnowFlake(int mid, int sid)
{
TimeStamp = Ts();
SerialNumber = sid;
MachineID = mid;
}
// 12位序列号
public int SerialNumber
{
get => m_data.BitField<int>(0, 12);
set => m_data.SetBitField(value, 0, 12);
}
// 41位时间戳
public long TimeStamp
{
get => m_data.BitField<long>(23, 41);
private set => m_data.SetBitField(value, 23, 41);
}
// 10位设备id
public int MachineID
{
get => m_data.BitField<int>(12, 10);
set => m_data.SetBitField(value, 12, 10);
}
// 内部数据用于存储实际bits
long m_data;
}0x02. RGBA In Graphic and Images (图形图像中的RGBA)
// sizeof(RGB565) = 2, := we can control the layout same as mData
struct RGB565
{
public byte R
{
get => mData.BitField<byte>(0, 5);
set => mData.SetBitField(value, 0, 5);
}
public byte G
{
get => mData.BitField<byte>(5, 6);
set => mData.SetBitField(value, 5, 6);
}
public byte B
{
get => mData.BitField<byte>(11, 5);
set => mData.SetBitField(value, 11, 5);
}
public ushort mData;
}
// sizeof(RGB5551) = 2, := we can control the layout same as mData
struct RGBA5551
{
public byte R
{
get => mData.BitField<byte>(0, 5);
set => mData.SetBitField(value, 0, 5);
}
public byte G
{
get => mData.BitField<byte>(5, 5);
set => mData.SetBitField(value, 5, 5);
}
public byte B
{
get => mData.BitField<byte>(10, 5);
set => mData.SetBitField(value, 10, 5);
}
public byte A
{
get => mData.BitField<byte>(15, 1);
set => mData.SetBitField(value, 15, 1);
}
public ushort mData;
}0x03. IPV6 Header (网络开发中的IPv6包头)
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | 版本 | 优先权 | 流 标 签 |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | 有效载荷长度 | 下一报头 | 跳限制 |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | |
// + +
// | |
// + 源 地 址 +
// | long |
// + +
// | |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | |
// + +
// | |
// + 目 的 地 址 +
// | long |
// + +
// | |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// sizeof(IPV6Head) = 8, := we can control the layout same as mData
// yes, I designed it on purpose. The memory layout is very clean.
// 所有例子我都是专门设计的, 内存布局十分干净, 可以方便的直接进行IO复制.
struct IPV6Head
{
public byte Version
{
get => mData.BitField<byte>(0, 4);
set => mData.SetBitfield(value, 0, 4);
}
public byte TrafficClass
{
get => mData.BitField<byte>(5, 8);
set => mData.SetBitField(value, 5, 8);
}
public int FlowLabel
{
get => mData.BitField<int>(12, 20);
set => mData.SetBitField(value, 12, 20);
}
public int PayloadLength
{
get => mData.BitField<int>(32, 16);
set => mData.SetBitField(value, 32, 16);
}
public byte NextHeader
{
get => mData.BitField<byte>(48, 8);
set => mData.SetBitField(value, 48, 8);
}
public byte HopLimit
{
get => mData.BitField<byte>(56, 8);
set => mData.SetBitField(value, 56, 8);
}
public ulong mData;
}0x04 [BitFields] Attribute模拟定义一个位域struct (需要 lib version >=1.0.10 and .net >= 9.0)
// 它的内存布局也是设计为与BaseType一致, 可以直接内存读写.
// like: var s = (Some)BinaryReader.ReadInt32(xx); or Use UnSafe.Read<Some>(ptr);
// Its memory layout is also designed to be consistent with that of BaseType,
// allowing for direct read and write operations in memory.
[BitFields(EBitFieldBaseType.Int64)]
public partial struct Some
{
[BitOffset(0, 8)] //
public partial byte Age { get; set; }
[BitOffset(8, 1)]
public partial bool Sex { get; set; }
[BitOffset(16, 12)]
internal partial int Year { get; set; }
[BitOffset(31, 1)]
public partial bool Sign { get; internal set; }
//[BitOffset(31, 1)] // 这个是无效的
public static bool Ok { get; }
}// then code generator will product code like this:
public partial struct Some
{
private Int64 data;
public partial Byte Age
{
get => data.BitField<Byte>(0, 8);
set => data.SetBitField<Byte>(value, 0, 8);
}
public partial Boolean Sex
{
get => data.BitField<Boolean>(8, 1);
set => data.SetBitField<Boolean>(value, 8, 1);
}
internal partial Int32 Year
{
get => data.BitField<Int32>(16, 12);
set => data.SetBitField<Int32>(value, 16, 12);
}
public partial Boolean Sign
{
get => data.BitField<Boolean>(31, 1);
internal set => data.SetBitField<Boolean>(value, 31, 1);
}
/// <summary>
/// 原型数据
/// </summary>
public Int64 Data() => data;
/// <summary>
/// 隐式转换为基础类型
/// </summary>
/// <param name="self"></param>
public static implicit operator Int64(Some self) => self.data;
/// <summary>
/// 从基础类型显式转换为当前类型
/// </summary>
/// <param name="mData"></param>
public static explicit operator Some(Int64 mData) => new() { data = mData };
/// <summary>
/// 序列化为字节数组
/// </summary>
/// <returns></returns>
public byte[] Bytes() => BytesUtil.Bytes(this);
/// <summary>
/// 序列化为网络序字节数组(大端序)
/// </summary>
/// <returns></returns>
public byte[] NetBytes()=> BytesUtil.NetBytes(this);
/// <summary>
/// 从字节数组反序列化数据结构
/// </summary>
/// <param name="bytes"></param>
/// <returns></returns>
public static Some CastFrom(byte[] bytes) => bytes.To<Some>();
}