Function parseBytea

encode.go:347–392

Parse a bytea value received from the server. Both "hex" and the legacy "escape" format are supported.

(s []byte)

// Parse a bytea value received from the server.  Both "hex" and the legacy
// "escape" format are supported.
func parseBytea(s []byte) (result []byte, err error) {
	// Hex format.
	if len(s) >= 2 && bytes.Equal(s[:2], []byte("\\x")) {
		s = s[2:] // trim off leading "\\x"
		result = make([]byte, hex.DecodedLen(len(s)))
		_, err := hex.Decode(result, s)
		if err != nil {
			return nil, err
		}
		return result, nil
	}

	// Escape format.
	for len(s) > 0 {
		if s[0] == '\\' {
			// escaped '\\'
			if len(s) >= 2 && s[1] == '\\' {
				result = append(result, '\\')
				s = s[2:]
				continue
			}

			// '\\' followed by an octal number
			if len(s) < 4 {
				return nil, fmt.Errorf("invalid bytea sequence %v", s)
			}
			r, err := strconv.ParseUint(string(s[1:4]), 8, 8)
			if err != nil {
				return nil, fmt.Errorf("could not parse bytea value: %w", err)
			}
			result = append(result, byte(r))
			s = s[4:]
		} else {
			// We hit an unescaped, raw byte.  Try to read in as many as
			// possible in one go.
			i := bytes.IndexByte(s, '\\')
			if i == -1 {
				result = append(result, s...)
				break
			}
			result = append(result, s[:i]...)
			s = s[i:]
		}
	}
	return result, nil
}

func encodeBytea(v []byte) (result []byte) {
	result = make([]byte, 2+hex.EncodedLen(len(v)))