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gotosocial/vendor/github.com/bytedance/sonic/ast/decode.go

431 lines
11 KiB
Go

package ast
import (
`encoding/base64`
`runtime`
`strconv`
`unsafe`
`github.com/bytedance/sonic/internal/native/types`
`github.com/bytedance/sonic/internal/rt`
)
const _blankCharsMask = (1 << ' ') | (1 << '\t') | (1 << '\r') | (1 << '\n')
const (
bytesNull = "null"
bytesTrue = "true"
bytesFalse = "false"
bytesObject = "{}"
bytesArray = "[]"
)
func isSpace(c byte) bool {
return (int(1<<c) & _blankCharsMask) != 0
}
func skipBlank(src string, pos int) int {
se := uintptr(rt.IndexChar(src, len(src)))
sp := uintptr(rt.IndexChar(src, pos))
for sp < se {
if !isSpace(*(*byte)(unsafe.Pointer(sp))) {
break
}
sp += 1
}
if sp >= se {
return -int(types.ERR_EOF)
}
runtime.KeepAlive(src)
return int(sp - uintptr(rt.IndexChar(src, 0)))
}
func decodeNull(src string, pos int) (ret int) {
ret = pos + 4
if ret > len(src) {
return -int(types.ERR_EOF)
}
if src[pos:ret] == bytesNull {
return ret
} else {
return -int(types.ERR_INVALID_CHAR)
}
}
func decodeTrue(src string, pos int) (ret int) {
ret = pos + 4
if ret > len(src) {
return -int(types.ERR_EOF)
}
if src[pos:ret] == bytesTrue {
return ret
} else {
return -int(types.ERR_INVALID_CHAR)
}
}
func decodeFalse(src string, pos int) (ret int) {
ret = pos + 5
if ret > len(src) {
return -int(types.ERR_EOF)
}
if src[pos:ret] == bytesFalse {
return ret
}
return -int(types.ERR_INVALID_CHAR)
}
func decodeString(src string, pos int) (ret int, v string) {
ret, ep := skipString(src, pos)
if ep == -1 {
(*rt.GoString)(unsafe.Pointer(&v)).Ptr = rt.IndexChar(src, pos+1)
(*rt.GoString)(unsafe.Pointer(&v)).Len = ret - pos - 2
return ret, v
}
vv, ok := unquoteBytes(rt.Str2Mem(src[pos:ret]))
if !ok {
return -int(types.ERR_INVALID_CHAR), ""
}
runtime.KeepAlive(src)
return ret, rt.Mem2Str(vv)
}
func decodeBinary(src string, pos int) (ret int, v []byte) {
var vv string
ret, vv = decodeString(src, pos)
if ret < 0 {
return ret, nil
}
var err error
v, err = base64.StdEncoding.DecodeString(vv)
if err != nil {
return -int(types.ERR_INVALID_CHAR), nil
}
return ret, v
}
func isDigit(c byte) bool {
return c >= '0' && c <= '9'
}
func decodeInt64(src string, pos int) (ret int, v int64, err error) {
sp := uintptr(rt.IndexChar(src, pos))
ss := uintptr(sp)
se := uintptr(rt.IndexChar(src, len(src)))
if uintptr(sp) >= se {
return -int(types.ERR_EOF), 0, nil
}
if c := *(*byte)(unsafe.Pointer(sp)); c == '-' {
sp += 1
}
if sp == se {
return -int(types.ERR_EOF), 0, nil
}
for ; sp < se; sp += uintptr(1) {
if !isDigit(*(*byte)(unsafe.Pointer(sp))) {
break
}
}
if sp < se {
if c := *(*byte)(unsafe.Pointer(sp)); c == '.' || c == 'e' || c == 'E' {
return -int(types.ERR_INVALID_NUMBER_FMT), 0, nil
}
}
var vv string
ret = int(uintptr(sp) - uintptr((*rt.GoString)(unsafe.Pointer(&src)).Ptr))
(*rt.GoString)(unsafe.Pointer(&vv)).Ptr = unsafe.Pointer(ss)
(*rt.GoString)(unsafe.Pointer(&vv)).Len = ret - pos
v, err = strconv.ParseInt(vv, 10, 64)
if err != nil {
//NOTICE: allow overflow here
if err.(*strconv.NumError).Err == strconv.ErrRange {
return ret, 0, err
}
return -int(types.ERR_INVALID_CHAR), 0, err
}
runtime.KeepAlive(src)
return ret, v, nil
}
func isNumberChars(c byte) bool {
return (c >= '0' && c <= '9') || c == '+' || c == '-' || c == 'e' || c == 'E' || c == '.'
}
func decodeFloat64(src string, pos int) (ret int, v float64, err error) {
sp := uintptr(rt.IndexChar(src, pos))
ss := uintptr(sp)
se := uintptr(rt.IndexChar(src, len(src)))
if uintptr(sp) >= se {
return -int(types.ERR_EOF), 0, nil
}
if c := *(*byte)(unsafe.Pointer(sp)); c == '-' {
sp += 1
}
if sp == se {
return -int(types.ERR_EOF), 0, nil
}
for ; sp < se; sp += uintptr(1) {
if !isNumberChars(*(*byte)(unsafe.Pointer(sp))) {
break
}
}
var vv string
ret = int(uintptr(sp) - uintptr((*rt.GoString)(unsafe.Pointer(&src)).Ptr))
(*rt.GoString)(unsafe.Pointer(&vv)).Ptr = unsafe.Pointer(ss)
(*rt.GoString)(unsafe.Pointer(&vv)).Len = ret - pos
v, err = strconv.ParseFloat(vv, 64)
if err != nil {
//NOTICE: allow overflow here
if err.(*strconv.NumError).Err == strconv.ErrRange {
return ret, 0, err
}
return -int(types.ERR_INVALID_CHAR), 0, err
}
runtime.KeepAlive(src)
return ret, v, nil
}
func decodeValue(src string, pos int) (ret int, v types.JsonState) {
pos = skipBlank(src, pos)
if pos < 0 {
return pos, types.JsonState{Vt: types.ValueType(pos)}
}
switch c := src[pos]; c {
case 'n':
ret = decodeNull(src, pos)
if ret < 0 {
return ret, types.JsonState{Vt: types.ValueType(ret)}
}
return ret, types.JsonState{Vt: types.V_NULL}
case '"':
var ep int
ret, ep = skipString(src, pos)
if ret < 0 {
return ret, types.JsonState{Vt: types.ValueType(ret)}
}
return ret, types.JsonState{Vt: types.V_STRING, Iv: int64(pos + 1), Ep: ep}
case '{':
return pos + 1, types.JsonState{Vt: types.V_OBJECT}
case '[':
return pos + 1, types.JsonState{Vt: types.V_ARRAY}
case 't':
ret = decodeTrue(src, pos)
if ret < 0 {
return ret, types.JsonState{Vt: types.ValueType(ret)}
}
return ret, types.JsonState{Vt: types.V_TRUE}
case 'f':
ret = decodeFalse(src, pos)
if ret < 0 {
return ret, types.JsonState{Vt: types.ValueType(ret)}
}
return ret, types.JsonState{Vt: types.V_FALSE}
case '-', '+', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
var iv int64
ret, iv, _ = decodeInt64(src, pos)
if ret >= 0 {
return ret, types.JsonState{Vt: types.V_INTEGER, Iv: iv, Ep: pos}
} else if ret != -int(types.ERR_INVALID_NUMBER_FMT) {
return ret, types.JsonState{Vt: types.ValueType(ret)}
}
var fv float64
ret, fv, _ = decodeFloat64(src, pos)
if ret >= 0 {
return ret, types.JsonState{Vt: types.V_DOUBLE, Dv: fv, Ep: pos}
} else {
return ret, types.JsonState{Vt: types.ValueType(ret)}
}
default:
return -int(types.ERR_INVALID_CHAR), types.JsonState{Vt:-types.ValueType(types.ERR_INVALID_CHAR)}
}
}
func skipNumber(src string, pos int) (ret int) {
sp := uintptr(rt.IndexChar(src, pos))
se := uintptr(rt.IndexChar(src, len(src)))
if uintptr(sp) >= se {
return -int(types.ERR_EOF)
}
if c := *(*byte)(unsafe.Pointer(sp)); c == '-' {
sp += 1
}
ss := sp
var pointer bool
var exponent bool
var lastIsDigit bool
var nextNeedDigit = true
for ; sp < se; sp += uintptr(1) {
c := *(*byte)(unsafe.Pointer(sp))
if isDigit(c) {
lastIsDigit = true
nextNeedDigit = false
continue
} else if nextNeedDigit {
return -int(types.ERR_INVALID_CHAR)
} else if c == '.' {
if !lastIsDigit || pointer || sp == ss {
return -int(types.ERR_INVALID_CHAR)
}
pointer = true
lastIsDigit = false
nextNeedDigit = true
continue
} else if c == 'e' || c == 'E' {
if !lastIsDigit || exponent {
return -int(types.ERR_INVALID_CHAR)
}
if sp == se-1 {
return -int(types.ERR_EOF)
}
exponent = true
lastIsDigit = false
nextNeedDigit = false
continue
} else if c == '-' || c == '+' {
if prev := *(*byte)(unsafe.Pointer(sp - 1)); prev != 'e' && prev != 'E' {
return -int(types.ERR_INVALID_CHAR)
}
lastIsDigit = false
nextNeedDigit = true
continue
} else {
break
}
}
if nextNeedDigit {
return -int(types.ERR_EOF)
}
runtime.KeepAlive(src)
return int(uintptr(sp) - uintptr((*rt.GoString)(unsafe.Pointer(&src)).Ptr))
}
func skipString(src string, pos int) (ret int, ep int) {
if pos+1 >= len(src) {
return -int(types.ERR_EOF), -1
}
sp := uintptr(rt.IndexChar(src, pos))
se := uintptr(rt.IndexChar(src, len(src)))
if *(*byte)(unsafe.Pointer(sp)) != '"' {
return -int(types.ERR_INVALID_CHAR), -1
}
sp += 1
ep = -1
for sp < se {
c := *(*byte)(unsafe.Pointer(sp))
if c == '\\' {
if ep == -1 {
ep = int(uintptr(sp) - uintptr((*rt.GoString)(unsafe.Pointer(&src)).Ptr))
}
sp += 2
continue
}
sp += 1
if c == '"' {
break
}
}
if sp > se {
return -int(types.ERR_EOF), -1
}
runtime.KeepAlive(src)
return int(uintptr(sp) - uintptr((*rt.GoString)(unsafe.Pointer(&src)).Ptr)), ep
}
func skipPair(src string, pos int, lchar byte, rchar byte) (ret int) {
if pos+1 >= len(src) {
return -int(types.ERR_EOF)
}
sp := uintptr(rt.IndexChar(src, pos))
se := uintptr(rt.IndexChar(src, len(src)))
if *(*byte)(unsafe.Pointer(sp)) != lchar {
return -int(types.ERR_INVALID_CHAR)
}
sp += 1
nbrace := 1
inquote := false
for sp < se {
c := *(*byte)(unsafe.Pointer(sp))
if c == '\\' {
sp += 2
continue
} else if c == '"' {
inquote = !inquote
} else if c == lchar {
if !inquote {
nbrace += 1
}
} else if c == rchar {
if !inquote {
nbrace -= 1
if nbrace == 0 {
sp += 1
break
}
}
}
sp += 1
}
if nbrace != 0 {
return -int(types.ERR_INVALID_CHAR)
}
runtime.KeepAlive(src)
return int(uintptr(sp) - uintptr((*rt.GoString)(unsafe.Pointer(&src)).Ptr))
}
func skipValue(src string, pos int) (ret int, start int) {
pos = skipBlank(src, pos)
if pos < 0 {
return pos, -1
}
switch c := src[pos]; c {
case 'n':
ret = decodeNull(src, pos)
case '"':
ret, _ = skipString(src, pos)
case '{':
ret = skipPair(src, pos, '{', '}')
case '[':
ret = skipPair(src, pos, '[', ']')
case 't':
ret = decodeTrue(src, pos)
case 'f':
ret = decodeFalse(src, pos)
case '-', '+', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
ret = skipNumber(src, pos)
default:
ret = -int(types.ERR_INVALID_CHAR)
}
return ret, pos
}