Fix decoding fields containing escaped characters

This commit is contained in:
Masaaki Goshima 2021-06-02 17:23:32 +09:00
parent 6562473b1e
commit c128c8c915
2 changed files with 105 additions and 30 deletions

View File

@ -6,6 +6,8 @@ import (
"math/bits"
"sort"
"strings"
"unicode"
"unicode/utf16"
"unsafe"
)
@ -136,6 +138,52 @@ func (d *structDecoder) tryOptimize() {
}
}
// decode from '\uXXXX'
func decodeKeyCharByUnicodeRune(buf []byte, cursor int64) ([]byte, int64) {
const defaultOffset = 4
const surrogateOffset = 6
r := unicodeToRune(buf[cursor : cursor+defaultOffset])
if utf16.IsSurrogate(r) {
cursor += defaultOffset
if cursor+surrogateOffset >= int64(len(buf)) || buf[cursor] != '\\' || buf[cursor+1] != 'u' {
return []byte(string(unicode.ReplacementChar)), cursor + defaultOffset - 1
}
cursor += 2
r2 := unicodeToRune(buf[cursor : cursor+defaultOffset])
if r := utf16.DecodeRune(r, r2); r != unicode.ReplacementChar {
return []byte(string(r)), cursor + defaultOffset - 1
}
}
return []byte(string(r)), cursor + defaultOffset - 1
}
func decodeKeyCharByEscapedChar(buf []byte, cursor int64) ([]byte, int64) {
c := buf[cursor]
cursor++
switch c {
case '"':
return []byte{'"'}, cursor
case '\\':
return []byte{'\\'}, cursor
case '/':
return []byte{'/'}, cursor
case 'b':
return []byte{'\b'}, cursor
case 'f':
return []byte{'\f'}, cursor
case 'n':
return []byte{'\n'}, cursor
case 'r':
return []byte{'\r'}, cursor
case 't':
return []byte{'\t'}, cursor
case 'u':
return decodeKeyCharByUnicodeRune(buf, cursor)
}
return nil, cursor
}
func decodeKeyByBitmapUint8(d *structDecoder, buf []byte, cursor int64) (int64, *structFieldSet, error) {
var (
field *structFieldSet
@ -174,24 +222,21 @@ func decodeKeyByBitmapUint8(d *structDecoder, buf []byte, cursor int64) (int64,
return cursor, field, nil
case nul:
return 0, nil, errUnexpectedEndOfJSON("string", cursor)
case '\\':
cursor++
chars, nextCursor := decodeKeyCharByEscapedChar(buf, cursor)
for _, c := range chars {
curBit &= bitmap[keyIdx][largeToSmallTable[c]]
if curBit == 0 {
return decodeKeyNotFound(b, cursor, field)
}
keyIdx++
}
cursor = nextCursor
default:
curBit &= bitmap[keyIdx][largeToSmallTable[c]]
if curBit == 0 {
for {
cursor++
switch char(b, cursor) {
case '"':
cursor++
return cursor, field, nil
case '\\':
cursor++
if char(b, cursor) == nul {
return 0, nil, errUnexpectedEndOfJSON("string", cursor)
}
case nul:
return 0, nil, errUnexpectedEndOfJSON("string", cursor)
}
}
return decodeKeyNotFound(b, cursor, field)
}
keyIdx++
}
@ -203,6 +248,24 @@ func decodeKeyByBitmapUint8(d *structDecoder, buf []byte, cursor int64) (int64,
}
}
func decodeKeyNotFound(b unsafe.Pointer, cursor int64, field *structFieldSet) (int64, *structFieldSet, error) {
for {
cursor++
switch char(b, cursor) {
case '"':
cursor++
return cursor, field, nil
case '\\':
cursor++
if char(b, cursor) == nul {
return 0, nil, errUnexpectedEndOfJSON("string", cursor)
}
case nul:
return 0, nil, errUnexpectedEndOfJSON("string", cursor)
}
}
}
func decodeKeyByBitmapUint16(d *structDecoder, buf []byte, cursor int64) (int64, *structFieldSet, error) {
var (
field *structFieldSet
@ -241,24 +304,21 @@ func decodeKeyByBitmapUint16(d *structDecoder, buf []byte, cursor int64) (int64,
return cursor, field, nil
case nul:
return 0, nil, errUnexpectedEndOfJSON("string", cursor)
case '\\':
cursor++
chars, nextCursor := decodeKeyCharByEscapedChar(buf, cursor)
for _, c := range chars {
curBit &= bitmap[keyIdx][largeToSmallTable[c]]
if curBit == 0 {
return decodeKeyNotFound(b, cursor, field)
}
keyIdx++
}
cursor = nextCursor
default:
curBit &= bitmap[keyIdx][largeToSmallTable[c]]
if curBit == 0 {
for {
cursor++
switch char(b, cursor) {
case '"':
cursor++
return cursor, field, nil
case '\\':
cursor++
if char(b, cursor) == nul {
return 0, nil, errUnexpectedEndOfJSON("string", cursor)
}
case nul:
return 0, nil, errUnexpectedEndOfJSON("string", cursor)
}
}
return decodeKeyNotFound(b, cursor, field)
}
keyIdx++
}

View File

@ -3594,3 +3594,18 @@ func TestIssue218(t *testing.T) {
})
}
}
func TestDecodeEscapedCharField(t *testing.T) {
b := []byte(`{"\u6D88\u606F":"\u6D88\u606F"}`)
t.Run("unmarshal", func(t *testing.T) {
v := struct {
Msg string `json:"消息"`
}{}
if err := json.Unmarshal(b, &v); err != nil {
t.Fatal(err)
}
if !bytes.Equal([]byte(v.Msg), []byte("消息")) {
t.Fatal("failed to decode unicode char")
}
})
}