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Remove unnecessary codes

This commit is contained in:
Masaaki Goshima 2021-12-27 22:28:25 +09:00
parent 0d18c6d7ce
commit 2d022aa037
No known key found for this signature in database
GPG Key ID: 6A53785055537153
2 changed files with 25 additions and 69 deletions
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15
internal/encoder/decode_rune.go
View File

@ -2,22 +2,7 @@ package encoder
import "unicode/utf8"
// Code points in the surrogate range are not valid for UTF-8.
const (
surrogateMin = 0xD800
surrogateMax = 0xDFFF
)
const (
maskx = 63 //0b00111111
mask2 = 31 //0b00011111
mask3 = 15 //0b00001111
mask4 = 7 //0b00000111
rune1Max = 1<<7 - 1
rune2Max = 1<<11 - 1
rune3Max = 1<<16 - 1
// The default lowest and highest continuation byte.
locb = 128 //0b10000000
hicb = 191 //0b10111111

79
internal/encoder/string.go
View File

@ -348,53 +348,6 @@ var needEscape = [256]bool{
var hex = "0123456789abcdef"
// escapeIndex finds the index of the first char in `s` that requires escaping.
// A char requires escaping if it's outside of the range of [0x20, 0x7F] or if
// it includes a double quote or backslash.
// If no chars in `s` require escaping, the return value is -1.
func escapeIndex(s string) int {
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 | below(n, 0x20) | contains(n, '"') | contains(n, '\\')
if (mask & msb) != 0 {
return bits.TrailingZeros64(mask&msb) / 8
}
}
valLen := len(s)
for i := len(chunks) * 8; i < valLen; i++ {
if needEscape[s[i]] {
return i
}
}
return -1
}
// below return a mask that can be used to determine if any of the bytes
// in `n` are below `b`. If a byte's MSB is set in the mask then that byte was
// below `b`. The result is only valid if `b`, and each byte in `n`, is below
// 0x80.
func below(n uint64, b byte) uint64 {
return n - expand(b)
}
// contains returns a mask that can be used to determine if any of the
// bytes in `n` are equal to `b`. If a byte's MSB is set in the mask then
// that byte is equal to `b`. The result is only valid if `b`, and each
// byte in `n`, is below 0x80.
func contains(n uint64, b byte) uint64 {
return (n ^ expand(b)) - lsb
}
// expand puts the specified byte into each of the 8 bytes of a uint64.
func expand(b byte) uint64 {
return lsb * uint64(b)
}
//nolint:govet
func stringToUint64Slice(s string) []uint64 {
return *(*[]uint64)(unsafe.Pointer(&reflect.SliceHeader{
@ -539,19 +492,37 @@ func appendString(buf []byte, s string) []byte {
return append(buf, `""`...)
}
buf = append(buf, '"')
var escapeIdx int
var (
i, j int
)
if valLen >= 8 {
if escapeIdx = escapeIndex(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)
if (mask & msb) != 0 {
j = bits.TrailingZeros64(mask&msb) / 8
goto ESCAPE_END
}
}
valLen := len(s)
for i := len(chunks) * 8; i < valLen; i++ {
if needEscape[s[i]] {
j = i
goto ESCAPE_END
}
}
return append(append(buf, s...), '"')
}
i := 0
j := escapeIdx
ESCAPE_END:
for j < valLen {
c := s[j]
if c >= 0x20 && c <= 0x7f && c != '\\' && c != '"' {
if !needEscape[c] {
// fast path: most of the time, printable ascii characters are used
j++
continue