Пример #1
0
        /// <summary>
        /// Encoded an integer to save space.
        /// </summary>
        /// <remarks>
        /// Integer can be encoded depending on the represented value to save space. Variable length integers always precede 
        /// an array/vector of a type of data that may vary in length. Longer numbers are encoded in little endian. 
        /// </remarks>
        /// <specification>https://en.bitcoin.it/wiki/Protocol_specification#Variable_length_integer</specification>
        /// <example>
        /// nodejs: https://c9.io/raistlinthewiz/bitcoin-coinbase-varint-nodejs
        /// </example>
        /// <returns></returns>
        public static byte[] VarInt(UInt32 value)
        {
            if (value < 0xfd)
                return new[] { (byte)value };

            byte[] result;

            using (var stream = new MemoryStream())
            {
                if (value < 0xffff)
                {
                    stream.WriteValueU8(0xfd);
                    stream.WriteValueU16(((UInt16)value).LittleEndian());
                }
                else if (value < 0xffffffff)
                {
                    stream.WriteValueU8(0xfe);
                    stream.WriteValueU32(value.LittleEndian());
                }
                else
                {
                    stream.WriteValueU8(0xff);
                    stream.WriteValueU16(((UInt16)value).LittleEndian());
                }
                result = stream.ToArray();
            }

            return result;
        }