go-json/decode_number.go

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package json
import (
"strconv"
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"unsafe"
)
type numberDecoder struct {
stringDecoder *stringDecoder
op func(unsafe.Pointer, Number)
structName string
fieldName string
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}
func newNumberDecoder(structName, fieldName string, op func(unsafe.Pointer, Number)) *numberDecoder {
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return &numberDecoder{
stringDecoder: newStringDecoder(structName, fieldName),
op: op,
structName: structName,
fieldName: fieldName,
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}
}
func (d *numberDecoder) decodeStream(s *stream, depth int64, p unsafe.Pointer) error {
bytes, err := d.decodeStreamByte(s)
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if err != nil {
return err
}
if _, err := strconv.ParseFloat(*(*string)(unsafe.Pointer(&bytes)), 64); err != nil {
return &SyntaxError{msg: err.Error(), Offset: s.totalOffset()}
}
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d.op(p, Number(string(bytes)))
s.reset()
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return nil
}
func (d *numberDecoder) decode(buf []byte, cursor, depth int64, p unsafe.Pointer) (int64, error) {
bytes, c, err := d.decodeByte(buf, cursor)
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if err != nil {
return 0, err
}
if _, err := strconv.ParseFloat(*(*string)(unsafe.Pointer(&bytes)), 64); err != nil {
return 0, &SyntaxError{msg: err.Error(), Offset: c}
}
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cursor = c
s := *(*string)(unsafe.Pointer(&bytes))
d.op(p, Number(s))
return cursor, nil
}
func (d *numberDecoder) decodeStreamByte(s *stream) ([]byte, error) {
for {
switch s.char() {
case ' ', '\n', '\t', '\r':
s.cursor++
continue
case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
return floatBytes(s), nil
case 'n':
if err := nullBytes(s); err != nil {
return nil, err
}
return nil, nil
case '"':
return d.stringDecoder.decodeStreamByte(s)
case nul:
if s.read() {
continue
}
goto ERROR
default:
goto ERROR
}
}
ERROR:
return nil, errUnexpectedEndOfJSON("json.Number", s.totalOffset())
}
func (d *numberDecoder) decodeByte(buf []byte, cursor int64) ([]byte, int64, error) {
buflen := int64(len(buf))
for ; cursor < buflen; cursor++ {
switch buf[cursor] {
case ' ', '\n', '\t', '\r':
continue
case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
start := cursor
cursor++
for ; cursor < buflen; cursor++ {
if floatTable[buf[cursor]] {
continue
}
break
}
num := buf[start:cursor]
return num, cursor, nil
case 'n':
if cursor+3 >= buflen {
return nil, 0, errUnexpectedEndOfJSON("null", cursor)
}
if buf[cursor+1] != 'u' {
return nil, 0, errInvalidCharacter(buf[cursor+1], "null", cursor)
}
if buf[cursor+2] != 'l' {
return nil, 0, errInvalidCharacter(buf[cursor+2], "null", cursor)
}
if buf[cursor+3] != 'l' {
return nil, 0, errInvalidCharacter(buf[cursor+3], "null", cursor)
}
cursor += 4
return nil, cursor, nil
case '"':
return d.stringDecoder.decodeByte(buf, cursor)
default:
return nil, 0, errUnexpectedEndOfJSON("json.Number", cursor)
}
}
return nil, 0, errUnexpectedEndOfJSON("json.Number", cursor)
}