Method Read

csharp/src/Fory/DecimalSerializer.cs:125–155

(ByteReader buffer)

    }

    public static (int Scale, BigInteger Unscaled) Read(ByteReader buffer)
    {
        int scale = buffer.ReadVarInt32();
        ulong header = buffer.ReadVarUInt64();
        if ((header & 1UL) == 0UL)
        {
            return (scale, new BigInteger(DecodeZigZag64(header >> 1)));
        }

        ulong meta = header >> 1;
        ulong lenLong = meta >> 1;
        if (lenLong == 0 || lenLong > int.MaxValue)
        {
            throw new InvalidDataException($"invalid decimal magnitude length {lenLong}");
        }

        int length = checked((int)lenLong);
        byte[] magnitudeBytes = buffer.ReadBytes(length);
        if (magnitudeBytes[^1] == 0)
        {
            throw new InvalidDataException("non-canonical decimal magnitude bytes: trailing zero byte");
        }

        BigInteger magnitude = new(magnitudeBytes, isUnsigned: true, isBigEndian: false);
        if (magnitude.IsZero)
        {
            throw new InvalidDataException("big decimal encoding must not represent zero");
        }

        return (scale, (meta & 1UL) == 0UL ? magnitude : BigInteger.Negate(magnitude));
    }

    private static bool CanUseSmallEncoding(BigInteger value)
    {