1 package decoder
2
3 import (
4 "fmt"
5 "reflect"
6 "unsafe"
7
8 "github.com/goccy/go-json/internal/errors"
9 "github.com/goccy/go-json/internal/runtime"
10 )
11
12 type intDecoder struct {
13 typ *runtime.Type
14 kind reflect.Kind
15 op func(unsafe.Pointer, int64)
16 structName string
17 fieldName string
18 }
19
20 func newIntDecoder(typ *runtime.Type, structName, fieldName string, op func(unsafe.Pointer, int64)) *intDecoder {
21 return &intDecoder{
22 typ: typ,
23 kind: typ.Kind(),
24 op: op,
25 structName: structName,
26 fieldName: fieldName,
27 }
28 }
29
30 func (d *intDecoder) typeError(buf []byte, offset int64) *errors.UnmarshalTypeError {
31 return &errors.UnmarshalTypeError{
32 Value: fmt.Sprintf("number %s", string(buf)),
33 Type: runtime.RType2Type(d.typ),
34 Struct: d.structName,
35 Field: d.fieldName,
36 Offset: offset,
37 }
38 }
39
40 var (
41 pow10i64 = [...]int64{
42 1e00, 1e01, 1e02, 1e03, 1e04, 1e05, 1e06, 1e07, 1e08, 1e09,
43 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18,
44 }
45 pow10i64Len = len(pow10i64)
46 )
47
48 func (d *intDecoder) parseInt(b []byte) (int64, error) {
49 isNegative := false
50 if b[0] == '-' {
51 b = b[1:]
52 isNegative = true
53 }
54 maxDigit := len(b)
55 if maxDigit > pow10i64Len {
56 return 0, fmt.Errorf("invalid length of number")
57 }
58 sum := int64(0)
59 for i := 0; i < maxDigit; i++ {
60 c := int64(b[i]) - 48
61 digitValue := pow10i64[maxDigit-i-1]
62 sum += c * digitValue
63 }
64 if isNegative {
65 return -1 * sum, nil
66 }
67 return sum, nil
68 }
69
70 var (
71 numTable = [256]bool{
72 '0': true,
73 '1': true,
74 '2': true,
75 '3': true,
76 '4': true,
77 '5': true,
78 '6': true,
79 '7': true,
80 '8': true,
81 '9': true,
82 }
83 )
84
85 var (
86 numZeroBuf = []byte{'0'}
87 )
88
89 func (d *intDecoder) decodeStreamByte(s *Stream) ([]byte, error) {
90 for {
91 switch s.char() {
92 case ' ', '\n', '\t', '\r':
93 s.cursor++
94 continue
95 case '-':
96 start := s.cursor
97 for {
98 s.cursor++
99 if numTable[s.char()] {
100 continue
101 } else if s.char() == nul {
102 if s.read() {
103 s.cursor--
104 continue
105 }
106 }
107 break
108 }
109 num := s.buf[start:s.cursor]
110 if len(num) < 2 {
111 goto ERROR
112 }
113 return num, nil
114 case '0':
115 s.cursor++
116 return numZeroBuf, nil
117 case '1', '2', '3', '4', '5', '6', '7', '8', '9':
118 start := s.cursor
119 for {
120 s.cursor++
121 if numTable[s.char()] {
122 continue
123 } else if s.char() == nul {
124 if s.read() {
125 s.cursor--
126 continue
127 }
128 }
129 break
130 }
131 num := s.buf[start:s.cursor]
132 return num, nil
133 case 'n':
134 if err := nullBytes(s); err != nil {
135 return nil, err
136 }
137 return nil, nil
138 case nul:
139 if s.read() {
140 continue
141 }
142 goto ERROR
143 default:
144 return nil, d.typeError([]byte{s.char()}, s.totalOffset())
145 }
146 }
147 ERROR:
148 return nil, errors.ErrUnexpectedEndOfJSON("number(integer)", s.totalOffset())
149 }
150
151 func (d *intDecoder) decodeByte(buf []byte, cursor int64) ([]byte, int64, error) {
152 b := (*sliceHeader)(unsafe.Pointer(&buf)).data
153 for {
154 switch char(b, cursor) {
155 case ' ', '\n', '\t', '\r':
156 cursor++
157 continue
158 case '0':
159 cursor++
160 return numZeroBuf, cursor, nil
161 case '-', '1', '2', '3', '4', '5', '6', '7', '8', '9':
162 start := cursor
163 cursor++
164 for numTable[char(b, cursor)] {
165 cursor++
166 }
167 num := buf[start:cursor]
168 return num, cursor, nil
169 case 'n':
170 if err := validateNull(buf, cursor); err != nil {
171 return nil, 0, err
172 }
173 cursor += 4
174 return nil, cursor, nil
175 default:
176 return nil, 0, d.typeError([]byte{char(b, cursor)}, cursor)
177 }
178 }
179 }
180
181 func (d *intDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
182 bytes, err := d.decodeStreamByte(s)
183 if err != nil {
184 return err
185 }
186 if bytes == nil {
187 return nil
188 }
189 i64, err := d.parseInt(bytes)
190 if err != nil {
191 return d.typeError(bytes, s.totalOffset())
192 }
193 switch d.kind {
194 case reflect.Int8:
195 if i64 < -1*(1<<7) || (1<<7) <= i64 {
196 return d.typeError(bytes, s.totalOffset())
197 }
198 case reflect.Int16:
199 if i64 < -1*(1<<15) || (1<<15) <= i64 {
200 return d.typeError(bytes, s.totalOffset())
201 }
202 case reflect.Int32:
203 if i64 < -1*(1<<31) || (1<<31) <= i64 {
204 return d.typeError(bytes, s.totalOffset())
205 }
206 }
207 d.op(p, i64)
208 s.reset()
209 return nil
210 }
211
212 func (d *intDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
213 bytes, c, err := d.decodeByte(ctx.Buf, cursor)
214 if err != nil {
215 return 0, err
216 }
217 if bytes == nil {
218 return c, nil
219 }
220 cursor = c
221
222 i64, err := d.parseInt(bytes)
223 if err != nil {
224 return 0, d.typeError(bytes, cursor)
225 }
226 switch d.kind {
227 case reflect.Int8:
228 if i64 < -1*(1<<7) || (1<<7) <= i64 {
229 return 0, d.typeError(bytes, cursor)
230 }
231 case reflect.Int16:
232 if i64 < -1*(1<<15) || (1<<15) <= i64 {
233 return 0, d.typeError(bytes, cursor)
234 }
235 case reflect.Int32:
236 if i64 < -1*(1<<31) || (1<<31) <= i64 {
237 return 0, d.typeError(bytes, cursor)
238 }
239 }
240 d.op(p, i64)
241 return cursor, nil
242 }
243
244 func (d *intDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
245 return nil, 0, fmt.Errorf("json: int decoder does not support decode path")
246 }
247
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