public uint256(byte[] vch, int offset, int length, bool lendian = true)
{
if (length != WIDTH_BYTE)
{
throw new FormatException("the byte array should be 32 bytes long");
}
#if HAS_SPAN
if (BitConverter.IsLittleEndian && lendian)
{
var uints = MemoryMarshal.Cast <byte, ulong>(vch.AsSpan().Slice(offset, length));
pn0 = uints[0];
pn1 = uints[1];
pn2 = uints[2];
pn3 = uints[3];
return;
}
#endif
if (!lendian)
{
if (length != vch.Length)
{
vch = vch.Take(32).ToArray();
}
vch = vch.Reverse().ToArray();
}
pn0 = Utils.ToUInt64(vch, offset + 8 * 0, true);
pn1 = Utils.ToUInt64(vch, offset + 8 * 1, true);
pn2 = Utils.ToUInt64(vch, offset + 8 * 2, true);
pn3 = Utils.ToUInt64(vch, offset + 8 * 3, true);
}
public uint256(ReadOnlySpan <byte> bytes)
{
if (bytes.Length != WIDTH_BYTE)
{
throw new FormatException("the byte array should be 32 bytes long");
}
if (BitConverter.IsLittleEndian)
{
var uints = MemoryMarshal.Cast <byte, ulong>(bytes);
pn0 = uints[0];
pn1 = uints[1];
pn2 = uints[2];
pn3 = uints[3];
return;
}
pn0 = Utils.ToUInt64(bytes.Slice(0), true);
pn1 = Utils.ToUInt64(bytes.Slice(8 * 1), true);
pn2 = Utils.ToUInt64(bytes.Slice(8 * 2), true);
pn3 = Utils.ToUInt64(bytes.Slice(8 * 3), true);
}
/// <summary>
/// Create a uint256 from a string in big endian
/// </summary>
/// <param name="str"></param>
public uint256(string str)
{
if (str == null)
{
throw new ArgumentNullException(nameof(str));
}
if (str.Length != 64)
{
if (str.StartsWith("0x", StringComparison.OrdinalIgnoreCase))
{
str = str.Substring(2);
}
str = str.Trim();
if (str.Length != 64)
{
throw new FormatException("A uint256 must be 64 characters");
}
}
#if HAS_SPAN
if (BitConverter.IsLittleEndian)
{
Span <byte> tmp = stackalloc byte[32];
Encoder.DecodeData(str, tmp);
tmp.Reverse();
Span <ulong> uints = MemoryMarshal.Cast <byte, ulong>(tmp);
pn0 = uints[0];
pn1 = uints[1];
pn2 = uints[2];
pn3 = uints[3];
return;
}
#endif
var bytes = Encoder.DecodeData(str);
Array.Reverse(bytes);
pn0 = Utils.ToUInt64(bytes, 8 * 0, true);
pn1 = Utils.ToUInt64(bytes, 8 * 1, true);
pn2 = Utils.ToUInt64(bytes, 8 * 2, true);
pn3 = Utils.ToUInt64(bytes, 8 * 3, true);
}
