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gotosocial/vendor/github.com/goccy/go-json/decode_string.go

356 lines
9.2 KiB
Go

package json
import (
"reflect"
"unicode"
"unicode/utf16"
"unicode/utf8"
"unsafe"
)
type stringDecoder struct {
structName string
fieldName string
}
func newStringDecoder(structName, fieldName string) *stringDecoder {
return &stringDecoder{
structName: structName,
fieldName: fieldName,
}
}
func (d *stringDecoder) errUnmarshalType(typeName string, offset int64) *UnmarshalTypeError {
return &UnmarshalTypeError{
Value: typeName,
Type: reflect.TypeOf(""),
Offset: offset,
Struct: d.structName,
Field: d.fieldName,
}
}
func (d *stringDecoder) decodeStream(s *stream, depth int64, p unsafe.Pointer) error {
bytes, err := d.decodeStreamByte(s)
if err != nil {
return err
}
if bytes == nil {
return nil
}
**(**string)(unsafe.Pointer(&p)) = *(*string)(unsafe.Pointer(&bytes))
s.reset()
return nil
}
func (d *stringDecoder) decode(buf []byte, cursor, depth int64, p unsafe.Pointer) (int64, error) {
bytes, c, err := d.decodeByte(buf, cursor)
if err != nil {
return 0, err
}
if bytes == nil {
return c, nil
}
cursor = c
**(**string)(unsafe.Pointer(&p)) = *(*string)(unsafe.Pointer(&bytes))
return cursor, nil
}
var (
hexToInt = [256]int{
'0': 0,
'1': 1,
'2': 2,
'3': 3,
'4': 4,
'5': 5,
'6': 6,
'7': 7,
'8': 8,
'9': 9,
'A': 10,
'B': 11,
'C': 12,
'D': 13,
'E': 14,
'F': 15,
'a': 10,
'b': 11,
'c': 12,
'd': 13,
'e': 14,
'f': 15,
}
)
func unicodeToRune(code []byte) rune {
var r rune
for i := 0; i < len(code); i++ {
r = r*16 + rune(hexToInt[code[i]])
}
return r
}
func decodeUnicodeRune(s *stream) (rune, int64, error) {
const defaultOffset = 5
const surrogateOffset = 11
if s.cursor+defaultOffset >= s.length {
if !s.read() {
return rune(0), 0, errInvalidCharacter(s.char(), "escaped string", s.totalOffset())
}
}
r := unicodeToRune(s.buf[s.cursor+1 : s.cursor+defaultOffset])
if utf16.IsSurrogate(r) {
if s.cursor+surrogateOffset >= s.length {
s.read()
}
if s.cursor+surrogateOffset >= s.length || s.buf[s.cursor+defaultOffset] != '\\' || s.buf[s.cursor+defaultOffset+1] != 'u' {
return unicode.ReplacementChar, defaultOffset, nil
}
r2 := unicodeToRune(s.buf[s.cursor+defaultOffset+2 : s.cursor+surrogateOffset])
if r := utf16.DecodeRune(r, r2); r != unicode.ReplacementChar {
return r, surrogateOffset, nil
}
}
return r, defaultOffset, nil
}
func decodeUnicode(s *stream) error {
const backSlashAndULen = 2 // length of \u
r, offset, err := decodeUnicodeRune(s)
if err != nil {
return err
}
unicode := []byte(string(r))
unicodeLen := int64(len(unicode))
s.buf = append(append(s.buf[:s.cursor-1], unicode...), s.buf[s.cursor+offset:]...)
unicodeOrgLen := offset - 1
s.length = s.length - (backSlashAndULen + (unicodeOrgLen - unicodeLen))
s.cursor = s.cursor - backSlashAndULen + unicodeLen
return nil
}
func decodeEscapeString(s *stream) error {
s.cursor++
RETRY:
switch s.buf[s.cursor] {
case '"':
s.buf[s.cursor] = '"'
case '\\':
s.buf[s.cursor] = '\\'
case '/':
s.buf[s.cursor] = '/'
case 'b':
s.buf[s.cursor] = '\b'
case 'f':
s.buf[s.cursor] = '\f'
case 'n':
s.buf[s.cursor] = '\n'
case 'r':
s.buf[s.cursor] = '\r'
case 't':
s.buf[s.cursor] = '\t'
case 'u':
return decodeUnicode(s)
case nul:
if !s.read() {
return errInvalidCharacter(s.char(), "escaped string", s.totalOffset())
}
goto RETRY
default:
return errUnexpectedEndOfJSON("string", s.totalOffset())
}
s.buf = append(s.buf[:s.cursor-1], s.buf[s.cursor:]...)
s.length--
s.cursor--
return nil
}
var (
runeErrBytes = []byte(string(utf8.RuneError))
runeErrBytesLen = int64(len(runeErrBytes))
)
func stringBytes(s *stream) ([]byte, error) {
_, cursor, p := s.stat()
cursor++ // skip double quote char
start := cursor
for {
switch char(p, cursor) {
case '\\':
s.cursor = cursor
if err := decodeEscapeString(s); err != nil {
return nil, err
}
cursor = s.cursor
case '"':
literal := s.buf[start:cursor]
cursor++
s.cursor = cursor
return literal, nil
case
// 0x00 is nul, 0x5c is '\\', 0x22 is '"' .
0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, // 0x00-0x0F
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, // 0x10-0x1F
0x20, 0x21 /*0x22,*/, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, // 0x20-0x2F
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, // 0x30-0x3F
0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, // 0x40-0x4F
0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B /*0x5C,*/, 0x5D, 0x5E, 0x5F, // 0x50-0x5F
0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, // 0x60-0x6F
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F: // 0x70-0x7F
// character is ASCII. skip to next char
case
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, // 0x80-0x8F
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, // 0x90-0x9F
0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, // 0xA0-0xAF
0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF, // 0xB0-0xBF
0xC0, 0xC1, // 0xC0-0xC1
0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF: // 0xF5-0xFE
// character is invalid
s.buf = append(append(append([]byte{}, s.buf[:cursor]...), runeErrBytes...), s.buf[cursor+1:]...)
_, _, p = s.stat()
cursor += runeErrBytesLen
s.length += runeErrBytesLen
continue
case nul:
s.cursor = cursor
if s.read() {
_, cursor, p = s.stat()
continue
}
goto ERROR
case 0xEF:
// RuneError is {0xEF, 0xBF, 0xBD}
if s.buf[cursor+1] == 0xBF && s.buf[cursor+2] == 0xBD {
// found RuneError: skip
cursor += 2
break
}
fallthrough
default:
// multi bytes character
r, _ := utf8.DecodeRune(s.buf[cursor:])
b := []byte(string(r))
if r == utf8.RuneError {
s.buf = append(append(append([]byte{}, s.buf[:cursor]...), b...), s.buf[cursor+1:]...)
_, _, p = s.stat()
}
cursor += int64(len(b))
s.length += int64(len(b))
continue
}
cursor++
}
ERROR:
return nil, errUnexpectedEndOfJSON("string", s.totalOffset())
}
func (d *stringDecoder) decodeStreamByte(s *stream) ([]byte, error) {
for {
switch s.char() {
case ' ', '\n', '\t', '\r':
s.cursor++
continue
case '[':
return nil, d.errUnmarshalType("array", s.totalOffset())
case '{':
return nil, d.errUnmarshalType("object", s.totalOffset())
case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
return nil, d.errUnmarshalType("number", s.totalOffset())
case '"':
return stringBytes(s)
case 'n':
if err := nullBytes(s); err != nil {
return nil, err
}
return nil, nil
case nul:
if s.read() {
continue
}
}
break
}
return nil, errNotAtBeginningOfValue(s.totalOffset())
}
func (d *stringDecoder) decodeByte(buf []byte, cursor int64) ([]byte, int64, error) {
for {
switch buf[cursor] {
case ' ', '\n', '\t', '\r':
cursor++
case '[':
return nil, 0, d.errUnmarshalType("array", cursor)
case '{':
return nil, 0, d.errUnmarshalType("object", cursor)
case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
return nil, 0, d.errUnmarshalType("number", cursor)
case '"':
cursor++
start := cursor
b := (*sliceHeader)(unsafe.Pointer(&buf)).data
for {
switch char(b, cursor) {
case '\\':
cursor++
switch char(b, cursor) {
case '"':
buf[cursor] = '"'
buf = append(buf[:cursor-1], buf[cursor:]...)
case '\\':
buf[cursor] = '\\'
buf = append(buf[:cursor-1], buf[cursor:]...)
case '/':
buf[cursor] = '/'
buf = append(buf[:cursor-1], buf[cursor:]...)
case 'b':
buf[cursor] = '\b'
buf = append(buf[:cursor-1], buf[cursor:]...)
case 'f':
buf[cursor] = '\f'
buf = append(buf[:cursor-1], buf[cursor:]...)
case 'n':
buf[cursor] = '\n'
buf = append(buf[:cursor-1], buf[cursor:]...)
case 'r':
buf[cursor] = '\r'
buf = append(buf[:cursor-1], buf[cursor:]...)
case 't':
buf[cursor] = '\t'
buf = append(buf[:cursor-1], buf[cursor:]...)
case 'u':
buflen := int64(len(buf))
if cursor+5 >= buflen {
return nil, 0, errUnexpectedEndOfJSON("escaped string", cursor)
}
code := unicodeToRune(buf[cursor+1 : cursor+5])
unicode := []byte(string(code))
buf = append(append(buf[:cursor-1], unicode...), buf[cursor+5:]...)
default:
return nil, 0, errUnexpectedEndOfJSON("escaped string", cursor)
}
continue
case '"':
literal := buf[start:cursor]
cursor++
return literal, cursor, nil
case nul:
return nil, 0, errUnexpectedEndOfJSON("string", cursor)
}
cursor++
}
case 'n':
if err := validateNull(buf, cursor); err != nil {
return nil, 0, err
}
cursor += 4
return nil, cursor, nil
default:
return nil, 0, errNotAtBeginningOfValue(cursor)
}
}
}