service/vendor/github.com/goccy/go-json/internal/decoder/int.go

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2023-12-21 22:17:40 +08:00
package decoder
import (
"fmt"
"reflect"
"unsafe"
"github.com/goccy/go-json/internal/errors"
"github.com/goccy/go-json/internal/runtime"
)
type intDecoder struct {
typ *runtime.Type
kind reflect.Kind
op func(unsafe.Pointer, int64)
structName string
fieldName string
}
func newIntDecoder(typ *runtime.Type, structName, fieldName string, op func(unsafe.Pointer, int64)) *intDecoder {
return &intDecoder{
typ: typ,
kind: typ.Kind(),
op: op,
structName: structName,
fieldName: fieldName,
}
}
func (d *intDecoder) typeError(buf []byte, offset int64) *errors.UnmarshalTypeError {
return &errors.UnmarshalTypeError{
Value: fmt.Sprintf("number %s", string(buf)),
Type: runtime.RType2Type(d.typ),
Struct: d.structName,
Field: d.fieldName,
Offset: offset,
}
}
var (
pow10i64 = [...]int64{
1e00, 1e01, 1e02, 1e03, 1e04, 1e05, 1e06, 1e07, 1e08, 1e09,
1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18,
}
pow10i64Len = len(pow10i64)
)
func (d *intDecoder) parseInt(b []byte) (int64, error) {
isNegative := false
if b[0] == '-' {
b = b[1:]
isNegative = true
}
maxDigit := len(b)
if maxDigit > pow10i64Len {
return 0, fmt.Errorf("invalid length of number")
}
sum := int64(0)
for i := 0; i < maxDigit; i++ {
c := int64(b[i]) - 48
digitValue := pow10i64[maxDigit-i-1]
sum += c * digitValue
}
if isNegative {
return -1 * sum, nil
}
return sum, nil
}
var (
numTable = [256]bool{
'0': true,
'1': true,
'2': true,
'3': true,
'4': true,
'5': true,
'6': true,
'7': true,
'8': true,
'9': true,
}
)
var (
numZeroBuf = []byte{'0'}
)
func (d *intDecoder) decodeStreamByte(s *Stream) ([]byte, error) {
for {
switch s.char() {
case ' ', '\n', '\t', '\r':
s.cursor++
continue
case '-':
start := s.cursor
for {
s.cursor++
if numTable[s.char()] {
continue
} else if s.char() == nul {
if s.read() {
s.cursor-- // for retry current character
continue
}
}
break
}
num := s.buf[start:s.cursor]
if len(num) < 2 {
goto ERROR
}
return num, nil
case '0':
s.cursor++
return numZeroBuf, nil
case '1', '2', '3', '4', '5', '6', '7', '8', '9':
start := s.cursor
for {
s.cursor++
if numTable[s.char()] {
continue
} else if s.char() == nul {
if s.read() {
s.cursor-- // for retry current character
continue
}
}
break
}
num := s.buf[start:s.cursor]
return num, nil
case 'n':
if err := nullBytes(s); err != nil {
return nil, err
}
return nil, nil
case nul:
if s.read() {
continue
}
goto ERROR
default:
return nil, d.typeError([]byte{s.char()}, s.totalOffset())
}
}
ERROR:
return nil, errors.ErrUnexpectedEndOfJSON("number(integer)", s.totalOffset())
}
func (d *intDecoder) decodeByte(buf []byte, cursor int64) ([]byte, int64, error) {
b := (*sliceHeader)(unsafe.Pointer(&buf)).data
for {
switch char(b, cursor) {
case ' ', '\n', '\t', '\r':
cursor++
continue
case '0':
cursor++
return numZeroBuf, cursor, nil
case '-', '1', '2', '3', '4', '5', '6', '7', '8', '9':
start := cursor
cursor++
for numTable[char(b, cursor)] {
cursor++
}
num := buf[start:cursor]
return num, cursor, nil
case 'n':
if err := validateNull(buf, cursor); err != nil {
return nil, 0, err
}
cursor += 4
return nil, cursor, nil
default:
return nil, 0, d.typeError([]byte{char(b, cursor)}, cursor)
}
}
}
func (d *intDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
bytes, err := d.decodeStreamByte(s)
if err != nil {
return err
}
if bytes == nil {
return nil
}
i64, err := d.parseInt(bytes)
if err != nil {
return d.typeError(bytes, s.totalOffset())
}
switch d.kind {
case reflect.Int8:
if i64 < -1*(1<<7) || (1<<7) <= i64 {
return d.typeError(bytes, s.totalOffset())
}
case reflect.Int16:
if i64 < -1*(1<<15) || (1<<15) <= i64 {
return d.typeError(bytes, s.totalOffset())
}
case reflect.Int32:
if i64 < -1*(1<<31) || (1<<31) <= i64 {
return d.typeError(bytes, s.totalOffset())
}
}
d.op(p, i64)
s.reset()
return nil
}
func (d *intDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
bytes, c, err := d.decodeByte(ctx.Buf, cursor)
if err != nil {
return 0, err
}
if bytes == nil {
return c, nil
}
cursor = c
i64, err := d.parseInt(bytes)
if err != nil {
return 0, d.typeError(bytes, cursor)
}
switch d.kind {
case reflect.Int8:
if i64 < -1*(1<<7) || (1<<7) <= i64 {
return 0, d.typeError(bytes, cursor)
}
case reflect.Int16:
if i64 < -1*(1<<15) || (1<<15) <= i64 {
return 0, d.typeError(bytes, cursor)
}
case reflect.Int32:
if i64 < -1*(1<<31) || (1<<31) <= i64 {
return 0, d.typeError(bytes, cursor)
}
}
d.op(p, i64)
return cursor, nil
}
func (d *intDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
return nil, 0, fmt.Errorf("json: int decoder does not support decode path")
}