Function EncodeByteArrayToRawBytes

pkg/sql/lex/encode.go:96–139

EncodeByteArrayToRawBytes converts a SQL-level byte array into raw bytes according to the encoding specification in "be". If the skipHexPrefix argument is set, the hexadecimal encoding does not prefix the output with "\x". This is suitable e.g. for the encode() built-in.

(data string, be BytesEncodeFormat, skipHexPrefix bool)

// prefix the output with "\x". This is suitable e.g. for the encode()
// built-in.
func EncodeByteArrayToRawBytes(data string, be BytesEncodeFormat, skipHexPrefix bool) string {
	switch be {
	case BytesEncodeHex:
		head := 2
		if skipHexPrefix {
			head = 0
		}
		res := make([]byte, head+hex.EncodedLen(len(data)))
		if !skipHexPrefix {
			res[0] = '\\'
			res[1] = 'x'
		}
		hex.Encode(res[head:], []byte(data))
		return string(res)

	case BytesEncodeEscape:
		// PostgreSQL does not allow all the escapes formats recognized by
		// CockroachDB's scanner. It only recognizes octal and \\ for the
		// backslash itself.
		// See https://www.postgresql.org/docs/current/static/datatype-binary.html#AEN5667
		res := make([]byte, 0, len(data))
		for _, c := range []byte(data) {
			if c == '\\' {
				res = append(res, '\\', '\\')
			} else if c < 32 || c >= 127 {
				// Escape the character in octal.
				//
				// Note: CockroachDB only supports UTF-8 for which all values
				// below 128 are ASCII. There is no locale-dependent escaping
				// in that case.
				res = append(res, '\\', '0'+(c>>6), '0'+((c>>3)&7), '0'+(c&7))
			} else {
				res = append(res, c)
			}
		}
		return string(res)

	case BytesEncodeBase64:
		return base64.StdEncoding.EncodeToString([]byte(data))

	default:
		panic(errors.AssertionFailedf("unhandled format: %s", be))
	}
}

// DecodeRawBytesToByteArray converts raw bytes to a SQL-level byte array
// according to the encoding specification in "be".