Function MinimallyEncode

model/script/scriptnum.go:192–237

(data []byte)

}

func MinimallyEncode(data []byte) []byte {
	dataLen := len(data)
	if dataLen == 0 {
		return data
	}

	// If the last byte is not 0x00 or 0x80, we are minimally encoded.
	last := data[dataLen-1]
	if (last & 0x7f) != 0 {
		return data
	}

	// If the script is one byte long, then we have a zero, which encodes as an
	// empty array.
	if len(data) == 1 {
		data = data[:0]
		return data
	}

	// If the next byte has it sign bit set, then we are minimaly encoded.
	if (data[len(data)-2] & 0x80) != 0 {
		return data
	}

	// We are not minimally encoded, we need to figure out how much to trim.
	for i := len(data) - 1; i > 0; i-- {
		// We found a non zero byte, time to encode.
		if data[i-1] != 0 {
			if (data[i-1] & 0x80) != 0 {
				// We found a byte with it sign bit set so we need one more
				// byte.
				data[i] = last
				i++
			} else {
				// the sign bit is clear, we can use it.
				data[i-1] |= last
			}
			data = data[:i]
			return data
		}
	}

	// If we the whole thing is zeros, then we have a zero.
	data = data[:0]
	return data
}

func IsMinimallyEncoded(data []byte, nMaxNumSize int64) bool {
	dataLen := len(data)