gotosocial/vendor/github.com/goccy/go-json/internal/decoder/uint.go
2023-02-25 12:12:40 +00:00

195 lines
4.2 KiB
Go

package decoder
import (
"fmt"
"reflect"
"unsafe"
"github.com/goccy/go-json/internal/errors"
"github.com/goccy/go-json/internal/runtime"
)
type uintDecoder struct {
typ *runtime.Type
kind reflect.Kind
op func(unsafe.Pointer, uint64)
structName string
fieldName string
}
func newUintDecoder(typ *runtime.Type, structName, fieldName string, op func(unsafe.Pointer, uint64)) *uintDecoder {
return &uintDecoder{
typ: typ,
kind: typ.Kind(),
op: op,
structName: structName,
fieldName: fieldName,
}
}
func (d *uintDecoder) typeError(buf []byte, offset int64) *errors.UnmarshalTypeError {
return &errors.UnmarshalTypeError{
Value: fmt.Sprintf("number %s", string(buf)),
Type: runtime.RType2Type(d.typ),
Offset: offset,
}
}
var (
pow10u64 = [...]uint64{
1e00, 1e01, 1e02, 1e03, 1e04, 1e05, 1e06, 1e07, 1e08, 1e09,
1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
}
pow10u64Len = len(pow10u64)
)
func (d *uintDecoder) parseUint(b []byte) (uint64, error) {
maxDigit := len(b)
if maxDigit > pow10u64Len {
return 0, fmt.Errorf("invalid length of number")
}
sum := uint64(0)
for i := 0; i < maxDigit; i++ {
c := uint64(b[i]) - 48
digitValue := pow10u64[maxDigit-i-1]
sum += c * digitValue
}
return sum, nil
}
func (d *uintDecoder) decodeStreamByte(s *Stream) ([]byte, error) {
for {
switch s.char() {
case ' ', '\n', '\t', '\r':
s.cursor++
continue
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
}
default:
return nil, d.typeError([]byte{s.char()}, s.totalOffset())
}
break
}
return nil, errors.ErrUnexpectedEndOfJSON("number(unsigned integer)", s.totalOffset())
}
func (d *uintDecoder) decodeByte(buf []byte, cursor int64) ([]byte, int64, error) {
for {
switch buf[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[buf[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{buf[cursor]}, cursor)
}
}
}
func (d *uintDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
bytes, err := d.decodeStreamByte(s)
if err != nil {
return err
}
if bytes == nil {
return nil
}
u64, err := d.parseUint(bytes)
if err != nil {
return d.typeError(bytes, s.totalOffset())
}
switch d.kind {
case reflect.Uint8:
if (1 << 8) <= u64 {
return d.typeError(bytes, s.totalOffset())
}
case reflect.Uint16:
if (1 << 16) <= u64 {
return d.typeError(bytes, s.totalOffset())
}
case reflect.Uint32:
if (1 << 32) <= u64 {
return d.typeError(bytes, s.totalOffset())
}
}
d.op(p, u64)
return nil
}
func (d *uintDecoder) 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
u64, err := d.parseUint(bytes)
if err != nil {
return 0, d.typeError(bytes, cursor)
}
switch d.kind {
case reflect.Uint8:
if (1 << 8) <= u64 {
return 0, d.typeError(bytes, cursor)
}
case reflect.Uint16:
if (1 << 16) <= u64 {
return 0, d.typeError(bytes, cursor)
}
case reflect.Uint32:
if (1 << 32) <= u64 {
return 0, d.typeError(bytes, cursor)
}
}
d.op(p, u64)
return cursor, nil
}
func (d *uintDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
return nil, 0, fmt.Errorf("json: uint decoder does not support decode path")
}