diff options
Diffstat (limited to 'vendor/github.com/goccy/go-json/internal/encoder/string.go')
| -rw-r--r-- | vendor/github.com/goccy/go-json/internal/encoder/string.go | 637 |
1 files changed, 637 insertions, 0 deletions
diff --git a/vendor/github.com/goccy/go-json/internal/encoder/string.go b/vendor/github.com/goccy/go-json/internal/encoder/string.go new file mode 100644 index 000000000..26da31a5e --- /dev/null +++ b/vendor/github.com/goccy/go-json/internal/encoder/string.go @@ -0,0 +1,637 @@ +package encoder + +import ( + "math/bits" + "reflect" + "unicode/utf8" + "unsafe" +) + +const ( + lsb = 0x0101010101010101 + msb = 0x8080808080808080 +) + +var needEscapeWithHTML = [256]bool{ + '"': true, + '&': true, + '<': true, + '>': true, + '\\': true, + 0x00: true, + 0x01: true, + 0x02: true, + 0x03: true, + 0x04: true, + 0x05: true, + 0x06: true, + 0x07: true, + 0x08: true, + 0x09: true, + 0x0a: true, + 0x0b: true, + 0x0c: true, + 0x0d: true, + 0x0e: true, + 0x0f: true, + 0x10: true, + 0x11: true, + 0x12: true, + 0x13: true, + 0x14: true, + 0x15: true, + 0x16: true, + 0x17: true, + 0x18: true, + 0x19: true, + 0x1a: true, + 0x1b: true, + 0x1c: true, + 0x1d: true, + 0x1e: true, + 0x1f: true, + /* 0x20 - 0x7f */ + 0x80: true, + 0x81: true, + 0x82: true, + 0x83: true, + 0x84: true, + 0x85: true, + 0x86: true, + 0x87: true, + 0x88: true, + 0x89: true, + 0x8a: true, + 0x8b: true, + 0x8c: true, + 0x8d: true, + 0x8e: true, + 0x8f: true, + 0x90: true, + 0x91: true, + 0x92: true, + 0x93: true, + 0x94: true, + 0x95: true, + 0x96: true, + 0x97: true, + 0x98: true, + 0x99: true, + 0x9a: true, + 0x9b: true, + 0x9c: true, + 0x9d: true, + 0x9e: true, + 0x9f: true, + 0xa0: true, + 0xa1: true, + 0xa2: true, + 0xa3: true, + 0xa4: true, + 0xa5: true, + 0xa6: true, + 0xa7: true, + 0xa8: true, + 0xa9: true, + 0xaa: true, + 0xab: true, + 0xac: true, + 0xad: true, + 0xae: true, + 0xaf: true, + 0xb0: true, + 0xb1: true, + 0xb2: true, + 0xb3: true, + 0xb4: true, + 0xb5: true, + 0xb6: true, + 0xb7: true, + 0xb8: true, + 0xb9: true, + 0xba: true, + 0xbb: true, + 0xbc: true, + 0xbd: true, + 0xbe: true, + 0xbf: true, + 0xc0: true, + 0xc1: true, + 0xc2: true, + 0xc3: true, + 0xc4: true, + 0xc5: true, + 0xc6: true, + 0xc7: true, + 0xc8: true, + 0xc9: true, + 0xca: true, + 0xcb: true, + 0xcc: true, + 0xcd: true, + 0xce: true, + 0xcf: true, + 0xd0: true, + 0xd1: true, + 0xd2: true, + 0xd3: true, + 0xd4: true, + 0xd5: true, + 0xd6: true, + 0xd7: true, + 0xd8: true, + 0xd9: true, + 0xda: true, + 0xdb: true, + 0xdc: true, + 0xdd: true, + 0xde: true, + 0xdf: true, + 0xe0: true, + 0xe1: true, + 0xe2: true, + 0xe3: true, + 0xe4: true, + 0xe5: true, + 0xe6: true, + 0xe7: true, + 0xe8: true, + 0xe9: true, + 0xea: true, + 0xeb: true, + 0xec: true, + 0xed: true, + 0xee: true, + 0xef: true, + 0xf0: true, + 0xf1: true, + 0xf2: true, + 0xf3: true, + 0xf4: true, + 0xf5: true, + 0xf6: true, + 0xf7: true, + 0xf8: true, + 0xf9: true, + 0xfa: true, + 0xfb: true, + 0xfc: true, + 0xfd: true, + 0xfe: true, + 0xff: true, +} + +var needEscape = [256]bool{ + '"': true, + '\\': true, + 0x00: true, + 0x01: true, + 0x02: true, + 0x03: true, + 0x04: true, + 0x05: true, + 0x06: true, + 0x07: true, + 0x08: true, + 0x09: true, + 0x0a: true, + 0x0b: true, + 0x0c: true, + 0x0d: true, + 0x0e: true, + 0x0f: true, + 0x10: true, + 0x11: true, + 0x12: true, + 0x13: true, + 0x14: true, + 0x15: true, + 0x16: true, + 0x17: true, + 0x18: true, + 0x19: true, + 0x1a: true, + 0x1b: true, + 0x1c: true, + 0x1d: true, + 0x1e: true, + 0x1f: true, + /* 0x20 - 0x7f */ + 0x80: true, + 0x81: true, + 0x82: true, + 0x83: true, + 0x84: true, + 0x85: true, + 0x86: true, + 0x87: true, + 0x88: true, + 0x89: true, + 0x8a: true, + 0x8b: true, + 0x8c: true, + 0x8d: true, + 0x8e: true, + 0x8f: true, + 0x90: true, + 0x91: true, + 0x92: true, + 0x93: true, + 0x94: true, + 0x95: true, + 0x96: true, + 0x97: true, + 0x98: true, + 0x99: true, + 0x9a: true, + 0x9b: true, + 0x9c: true, + 0x9d: true, + 0x9e: true, + 0x9f: true, + 0xa0: true, + 0xa1: true, + 0xa2: true, + 0xa3: true, + 0xa4: true, + 0xa5: true, + 0xa6: true, + 0xa7: true, + 0xa8: true, + 0xa9: true, + 0xaa: true, + 0xab: true, + 0xac: true, + 0xad: true, + 0xae: true, + 0xaf: true, + 0xb0: true, + 0xb1: true, + 0xb2: true, + 0xb3: true, + 0xb4: true, + 0xb5: true, + 0xb6: true, + 0xb7: true, + 0xb8: true, + 0xb9: true, + 0xba: true, + 0xbb: true, + 0xbc: true, + 0xbd: true, + 0xbe: true, + 0xbf: true, + 0xc0: true, + 0xc1: true, + 0xc2: true, + 0xc3: true, + 0xc4: true, + 0xc5: true, + 0xc6: true, + 0xc7: true, + 0xc8: true, + 0xc9: true, + 0xca: true, + 0xcb: true, + 0xcc: true, + 0xcd: true, + 0xce: true, + 0xcf: true, + 0xd0: true, + 0xd1: true, + 0xd2: true, + 0xd3: true, + 0xd4: true, + 0xd5: true, + 0xd6: true, + 0xd7: true, + 0xd8: true, + 0xd9: true, + 0xda: true, + 0xdb: true, + 0xdc: true, + 0xdd: true, + 0xde: true, + 0xdf: true, + 0xe0: true, + 0xe1: true, + 0xe2: true, + 0xe3: true, + 0xe4: true, + 0xe5: true, + 0xe6: true, + 0xe7: true, + 0xe8: true, + 0xe9: true, + 0xea: true, + 0xeb: true, + 0xec: true, + 0xed: true, + 0xee: true, + 0xef: true, + 0xf0: true, + 0xf1: true, + 0xf2: true, + 0xf3: true, + 0xf4: true, + 0xf5: true, + 0xf6: true, + 0xf7: true, + 0xf8: true, + 0xf9: true, + 0xfa: true, + 0xfb: true, + 0xfc: true, + 0xfd: true, + 0xfe: true, + 0xff: true, +} + +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{ + Data: ((*reflect.StringHeader)(unsafe.Pointer(&s))).Data, + Len: len(s) / 8, + Cap: len(s) / 8, + })) +} + +func AppendEscapedString(buf []byte, s string) []byte { + valLen := len(s) + if valLen == 0 { + return append(buf, `""`...) + } + buf = append(buf, '"') + var ( + i, j int + ) + if valLen >= 8 { + 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...), '"') + } +ESCAPE_END: + for j < valLen { + c := s[j] + + if !needEscapeWithHTML[c] { + // fast path: most of the time, printable ascii characters are used + j++ + continue + } + + switch c { + case '\\', '"': + buf = append(buf, s[i:j]...) + buf = append(buf, '\\', c) + i = j + 1 + j = j + 1 + continue + + case '\n': + buf = append(buf, s[i:j]...) + buf = append(buf, '\\', 'n') + i = j + 1 + j = j + 1 + continue + + case '\r': + buf = append(buf, s[i:j]...) + buf = append(buf, '\\', 'r') + i = j + 1 + j = j + 1 + continue + + case '\t': + buf = append(buf, s[i:j]...) + buf = append(buf, '\\', 't') + i = j + 1 + j = j + 1 + continue + + case '<', '>', '&': + buf = append(buf, s[i:j]...) + buf = append(buf, `\u00`...) + buf = append(buf, hex[c>>4], hex[c&0xF]) + i = j + 1 + j = j + 1 + continue + } + + // This encodes bytes < 0x20 except for \t, \n and \r. + if c < 0x20 { + buf = append(buf, s[i:j]...) + buf = append(buf, `\u00`...) + buf = append(buf, hex[c>>4], hex[c&0xF]) + i = j + 1 + j = j + 1 + continue + } + + r, size := utf8.DecodeRuneInString(s[j:]) + + if r == utf8.RuneError && size == 1 { + buf = append(buf, s[i:j]...) + buf = append(buf, `\ufffd`...) + i = j + size + j = j + size + continue + } + + switch r { + case '\u2028', '\u2029': + // U+2028 is LINE SEPARATOR. + // U+2029 is PARAGRAPH SEPARATOR. + // They are both technically valid characters in JSON strings, + // but don't work in JSONP, which has to be evaluated as JavaScript, + // and can lead to security holes there. It is valid JSON to + // escape them, so we do so unconditionally. + // See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion. + buf = append(buf, s[i:j]...) + buf = append(buf, `\u202`...) + buf = append(buf, hex[r&0xF]) + i = j + size + j = j + size + continue + } + + j += size + } + + return append(append(buf, s[i:]...), '"') +} + +func AppendString(buf []byte, s string) []byte { + valLen := len(s) + if valLen == 0 { + return append(buf, `""`...) + } + buf = append(buf, '"') + var escapeIdx int + if valLen >= 8 { + if escapeIdx = escapeIndex(s); escapeIdx < 0 { + return append(append(buf, s...), '"') + } + } + + i := 0 + j := escapeIdx + for j < valLen { + c := s[j] + + if c >= 0x20 && c <= 0x7f && c != '\\' && c != '"' { + // fast path: most of the time, printable ascii characters are used + j++ + continue + } + + switch c { + case '\\', '"': + buf = append(buf, s[i:j]...) + buf = append(buf, '\\', c) + i = j + 1 + j = j + 1 + continue + + case '\n': + buf = append(buf, s[i:j]...) + buf = append(buf, '\\', 'n') + i = j + 1 + j = j + 1 + continue + + case '\r': + buf = append(buf, s[i:j]...) + buf = append(buf, '\\', 'r') + i = j + 1 + j = j + 1 + continue + + case '\t': + buf = append(buf, s[i:j]...) + buf = append(buf, '\\', 't') + i = j + 1 + j = j + 1 + continue + + case '<', '>', '&': + buf = append(buf, s[i:j]...) + buf = append(buf, `\u00`...) + buf = append(buf, hex[c>>4], hex[c&0xF]) + i = j + 1 + j = j + 1 + continue + } + + // This encodes bytes < 0x20 except for \t, \n and \r. + if c < 0x20 { + buf = append(buf, s[i:j]...) + buf = append(buf, `\u00`...) + buf = append(buf, hex[c>>4], hex[c&0xF]) + i = j + 1 + j = j + 1 + continue + } + + r, size := utf8.DecodeRuneInString(s[j:]) + + if r == utf8.RuneError && size == 1 { + buf = append(buf, s[i:j]...) + buf = append(buf, `\ufffd`...) + i = j + size + j = j + size + continue + } + + switch r { + case '\u2028', '\u2029': + // U+2028 is LINE SEPARATOR. + // U+2029 is PARAGRAPH SEPARATOR. + // They are both technically valid characters in JSON strings, + // but don't work in JSONP, which has to be evaluated as JavaScript, + // and can lead to security holes there. It is valid JSON to + // escape them, so we do so unconditionally. + // See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion. + buf = append(buf, s[i:j]...) + buf = append(buf, `\u202`...) + buf = append(buf, hex[r&0xF]) + i = j + size + j = j + size + continue + } + + j += size + } + + return append(append(buf, s[i:]...), '"') +} |