Function SanitizeUTF8String

backend/common/util.go:181–222

SanitizeUTF8String returns a copy of the string s with each run of invalid or unprintable UTF-8 byte sequences replaced by its hexadecimal representation string.

(s string)

// SanitizeUTF8String returns a copy of the string s with each run of invalid or unprintable UTF-8 byte sequences
// replaced by its hexadecimal representation string.
func SanitizeUTF8String(s string) string {
	var b strings.Builder

	for i, c := range s {
		if c != utf8.RuneError {
			continue
		}

		_, wid := utf8.DecodeRuneInString(s[i:])
		if wid == 1 {
			b.Grow(len(s))
			_, _ = b.WriteString(s[:i])
			s = s[i:]
			break
		}
	}

	// Fast path for unchanged input
	if b.Cap() == 0 { // didn't call b.Grow above
		return s
	}

	for i := 0; i < len(s); {
		c := s[i]
		// U+0000-U+0019 are control characters
		if 0x20 <= c && c < utf8.RuneSelf {
			i++
			_ = b.WriteByte(c)
			continue
		}
		_, wid := utf8.DecodeRuneInString(s[i:])
		if wid == 1 {
			i++
			_, _ = fmt.Fprintf(&b, "\\x%02x", c)
			continue
		}
		_, _ = b.WriteString(s[i : i+wid])
		i += wid
	}

	return b.String()
}

func FormatMaximumSQLResultSizeMessage(limit int64) string {
	return fmt.Sprintf("Output of query exceeds max allowed output size of %dMB", limit/1024/1024)