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Expand source for string encoding

This commit is contained in:
Masaaki Goshima 2020-12-20 03:37:31 +09:00
parent 01b439e41e
commit fdce754b17
1 changed files with 34 additions and 7 deletions
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41
encode_string.go
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@ -725,7 +725,12 @@ func escapeIndexWithHTMLEscape(s string) int {
// combine masks before checking for the MSB of each byte. We include
// `n` in the mask to check whether any of the *input* byte MSBs were
// set (i.e. the byte was outside the ASCII range).
mask := n | below(n, 0x20) | contains(n, '"') | contains(n, '\\') | contains(n, '<') | contains(n, '>') | contains(n, '&')
mask := n | (n - (lsb * 0x20)) |
((n ^ (lsb * '"')) - lsb) |
((n ^ (lsb * '\\')) - lsb) |
((n ^ (lsb * '<')) - lsb) |
((n ^ (lsb * '>')) - lsb) |
((n ^ (lsb * '&')) - lsb)
if (mask & msb) != 0 {
return bits.TrailingZeros64(mask&msb) / 8
}
@ -776,18 +781,40 @@ func encodeEscapedString(buf []byte, s string) []byte {
return append(buf, `""`...)
}
buf = append(buf, '"')
var escapeIdx int
var (
i, j int
)
if valLen >= 8 {
if escapeIdx = escapeIndexWithHTMLEscape(s); escapeIdx < 0 {
return append(append(buf, s...), '"')
chunks := stringToUint64Slice(s)
for _, n := range chunks {
// combine masks before checking for the MSB of each byte. We include
// `n` in the mask to check whether any of the *input* byte MSBs were
// set (i.e. the byte was outside the ASCII range).
mask := n | (n - (lsb * 0x20)) |
((n ^ (lsb * '"')) - lsb) |
((n ^ (lsb * '\\')) - lsb) |
((n ^ (lsb * '<')) - lsb) |
((n ^ (lsb * '>')) - lsb) |
((n ^ (lsb * '&')) - lsb)
if (mask & msb) != 0 {
j = bits.TrailingZeros64(mask&msb) / 8
goto ESCAPE_END
}
}
for i := len(chunks) * 8; i < valLen; i++ {
if needEscapeWithHTML[s[i]] {
j = i
goto ESCAPE_END
}
}
// no found any escape characters.
return append(append(buf, s...), '"')
}
i := 0
j := escapeIdx
ESCAPE_END:
for j < valLen {
c := s[j]
if c >= 0x20 && c <= 0x7f && c != '\\' && c != '"' && (c != '<' && c != '>' && c != '&') {
if !needEscapeWithHTML[c] {
// fast path: most of the time, printable ascii characters are used
j++
continue