-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathdecoder.go
More file actions
489 lines (443 loc) · 10.3 KB
/
decoder.go
File metadata and controls
489 lines (443 loc) · 10.3 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
package msgpck
import (
"encoding/binary"
"math"
)
// Decoder reads MessagePack data from a byte slice.
// It provides zero-copy decoding where possible.
type Decoder struct {
data []byte
pos int
cfg Config
depth int
}
// NewDecoder creates a new Decoder for the given data with default config
func NewDecoder(data []byte) *Decoder {
return &Decoder{
data: data,
cfg: DefaultConfig(),
}
}
// NewDecoderWithConfig creates a new Decoder with custom config
func NewDecoderWithConfig(data []byte, cfg Config) *Decoder {
return &Decoder{
data: data,
cfg: cfg,
}
}
// Reset resets the decoder to decode new data
func (d *Decoder) Reset(data []byte) {
d.data = data
d.pos = 0
d.depth = 0
}
// Remaining returns the number of unread bytes
func (d *Decoder) Remaining() int {
return len(d.data) - d.pos
}
// Position returns the current position in the data
func (d *Decoder) Position() int {
return d.pos
}
// hasBytes returns true if there are at least n bytes remaining
func (d *Decoder) hasBytes(n int) bool {
return d.pos+n <= len(d.data)
}
// readByte reads a single byte
func (d *Decoder) readByte() (byte, error) {
if d.pos >= len(d.data) {
return 0, ErrUnexpectedEOF
}
b := d.data[d.pos]
d.pos++
return b, nil
}
// peekByte returns the next byte without consuming it
func (d *Decoder) peekByte() (byte, error) {
if d.pos >= len(d.data) {
return 0, ErrUnexpectedEOF
}
return d.data[d.pos], nil
}
// readBytes reads n bytes and returns a slice into the source
func (d *Decoder) readBytes(n int) ([]byte, error) {
if !d.hasBytes(n) {
return nil, ErrUnexpectedEOF
}
b := d.data[d.pos : d.pos+n]
d.pos += n
return b, nil
}
// readUint8 reads a uint8
func (d *Decoder) readUint8() (uint8, error) {
b, err := d.readByte()
return b, err
}
// readUint16 reads a big-endian uint16
func (d *Decoder) readUint16() (uint16, error) {
if !d.hasBytes(2) {
return 0, ErrUnexpectedEOF
}
v := binary.BigEndian.Uint16(d.data[d.pos:])
d.pos += 2
return v, nil
}
// readUint32 reads a big-endian uint32
func (d *Decoder) readUint32() (uint32, error) {
if !d.hasBytes(4) {
return 0, ErrUnexpectedEOF
}
v := binary.BigEndian.Uint32(d.data[d.pos:])
d.pos += 4
return v, nil
}
// readUint64 reads a big-endian uint64
func (d *Decoder) readUint64() (uint64, error) {
if !d.hasBytes(8) {
return 0, ErrUnexpectedEOF
}
v := binary.BigEndian.Uint64(d.data[d.pos:])
d.pos += 8
return v, nil
}
// readInt8 reads an int8
func (d *Decoder) readInt8() (int8, error) {
b, err := d.readByte()
return int8(b), err
}
// readInt16 reads a big-endian int16
func (d *Decoder) readInt16() (int16, error) {
v, err := d.readUint16()
return int16(v), err
}
// readInt32 reads a big-endian int32
func (d *Decoder) readInt32() (int32, error) {
v, err := d.readUint32()
return int32(v), err
}
// readInt64 reads a big-endian int64
func (d *Decoder) readInt64() (int64, error) {
v, err := d.readUint64()
return int64(v), err
}
// readFloat32 reads a big-endian float32
func (d *Decoder) readFloat32() (float32, error) {
v, err := d.readUint32()
if err != nil {
return 0, err
}
return math.Float32frombits(v), nil
}
// readFloat64 reads a big-endian float64
func (d *Decoder) readFloat64() (float64, error) {
v, err := d.readUint64()
if err != nil {
return 0, err
}
return math.Float64frombits(v), nil
}
// enterContainer increments depth and checks MaxDepth
func (d *Decoder) enterContainer() error {
d.depth++
if d.depth > d.cfg.MaxDepth {
return ErrMaxDepthExceeded
}
return nil
}
// leaveContainer decrements depth
func (d *Decoder) leaveContainer() {
d.depth--
}
// validateStringLen checks if length is valid for a string
func (d *Decoder) validateStringLen(length int) error {
if length > d.cfg.MaxStringLen {
return ErrStringTooLong
}
if !d.hasBytes(length) {
return ErrUnexpectedEOF
}
return nil
}
// validateBinaryLen checks if length is valid for binary data
func (d *Decoder) validateBinaryLen(length int) error {
if length > d.cfg.MaxBinaryLen {
return ErrBinaryTooLong
}
if !d.hasBytes(length) {
return ErrUnexpectedEOF
}
return nil
}
// validateArrayLen checks if length is valid for an array
func (d *Decoder) validateArrayLen(length int) error {
if length > d.cfg.MaxArrayLen {
return ErrArrayTooLong
}
// Sanity check: each element needs at least 1 byte
if !d.hasBytes(length) {
return ErrUnexpectedEOF
}
return nil
}
// validateMapLen checks if length is valid for a map
func (d *Decoder) validateMapLen(length int) error {
if length > d.cfg.MaxMapLen {
return ErrMapTooLong
}
// Sanity check: each key-value pair needs at least 2 bytes
if !d.hasBytes(length * 2) {
return ErrUnexpectedEOF
}
return nil
}
// validateExtLen checks if length is valid for ext data
func (d *Decoder) validateExtLen(length int) error {
if length > d.cfg.MaxExtLen {
return ErrExtTooLong
}
if !d.hasBytes(length) {
return ErrUnexpectedEOF
}
return nil
}
// readStringBytes reads a string and returns raw bytes (zero-copy).
// Used by struct decoders and typed decode functions.
func (d *Decoder) readStringBytes() ([]byte, error) {
format, err := d.readByte()
if err != nil {
return nil, err
}
var length int
if isFixstr(format) {
length = fixstrLen(format)
} else {
switch format {
case formatStr8:
n, err := d.readUint8()
if err != nil {
return nil, err
}
length = int(n)
case formatStr16:
n, err := d.readUint16()
if err != nil {
return nil, err
}
length = int(n)
case formatStr32:
n, err := d.readUint32()
if err != nil {
return nil, err
}
length = int(n)
default:
return nil, ErrTypeMismatch
}
}
if err := d.validateStringLen(length); err != nil {
return nil, err
}
return d.readBytes(length)
}
// DecodeInt64Array decodes an array of int64 values.
// More efficient than decoding elements individually.
func (d *Decoder) DecodeInt64Array() ([]int64, error) {
format, err := d.readByte()
if err != nil {
return nil, err
}
arrLen, err := d.parseArrayLen(format)
if err != nil {
return nil, err
}
if err := d.validateArrayLen(arrLen); err != nil {
return nil, err
}
result := make([]int64, arrLen)
for i := 0; i < arrLen; i++ {
format, err := d.readByte()
if err != nil {
return nil, err
}
result[i], err = d.decodeInt(format)
if err != nil {
return nil, err
}
}
return result, nil
}
// DecodeUint64Array decodes an array of uint64 values.
// More efficient than decoding elements individually.
func (d *Decoder) DecodeUint64Array() ([]uint64, error) {
format, err := d.readByte()
if err != nil {
return nil, err
}
arrLen, err := d.parseArrayLen(format)
if err != nil {
return nil, err
}
if err := d.validateArrayLen(arrLen); err != nil {
return nil, err
}
result := make([]uint64, arrLen)
for i := 0; i < arrLen; i++ {
format, err := d.readByte()
if err != nil {
return nil, err
}
result[i], err = d.decodeUint(format)
if err != nil {
return nil, err
}
}
return result, nil
}
// DecodeFloat64Array decodes an array of float64 values.
// More efficient than decoding elements individually.
func (d *Decoder) DecodeFloat64Array() ([]float64, error) {
format, err := d.readByte()
if err != nil {
return nil, err
}
arrLen, err := d.parseArrayLen(format)
if err != nil {
return nil, err
}
if err := d.validateArrayLen(arrLen); err != nil {
return nil, err
}
result := make([]float64, arrLen)
for i := 0; i < arrLen; i++ {
format, err := d.readByte()
if err != nil {
return nil, err
}
v, err := d.decodeFloat(format)
if err != nil {
return nil, err
}
result[i] = v
}
return result, nil
}
// DecodeStringArray decodes an array of strings (with copy).
// More efficient than decoding elements individually.
func (d *Decoder) DecodeStringArray() ([]string, error) {
format, err := d.readByte()
if err != nil {
return nil, err
}
arrLen, err := d.parseArrayLen(format)
if err != nil {
return nil, err
}
if err := d.validateArrayLen(arrLen); err != nil {
return nil, err
}
result := make([]string, arrLen)
for i := 0; i < arrLen; i++ {
bytes, err := d.readStringBytes()
if err != nil {
return nil, err
}
result[i] = string(bytes)
}
return result, nil
}
// decodeInt decodes an integer from the given format byte.
func (d *Decoder) decodeInt(format byte) (int64, error) {
if isPositiveFixint(format) {
return int64(format), nil
}
if isNegativeFixint(format) {
return int64(int8(format)), nil
}
switch format {
case formatUint8:
v, err := d.readUint8()
return int64(v), err
case formatUint16:
v, err := d.readUint16()
return int64(v), err
case formatUint32:
v, err := d.readUint32()
return int64(v), err
case formatUint64:
v, err := d.readUint64()
return int64(v), err
case formatInt8:
v, err := d.readInt8()
return int64(v), err
case formatInt16:
v, err := d.readInt16()
return int64(v), err
case formatInt32:
v, err := d.readInt32()
return int64(v), err
case formatInt64:
return d.readInt64()
default:
return 0, ErrTypeMismatch
}
}
// decodeUint decodes an unsigned integer from the given format byte.
func (d *Decoder) decodeUint(format byte) (uint64, error) {
if isPositiveFixint(format) {
return uint64(format), nil
}
switch format {
case formatUint8:
v, err := d.readUint8()
return uint64(v), err
case formatUint16:
v, err := d.readUint16()
return uint64(v), err
case formatUint32:
v, err := d.readUint32()
return uint64(v), err
case formatUint64:
return d.readUint64()
default:
return 0, ErrTypeMismatch
}
}
// decodeFloat decodes a float from the given format byte.
func (d *Decoder) decodeFloat(format byte) (float64, error) {
if isPositiveFixint(format) {
return float64(format), nil
}
if isNegativeFixint(format) {
return float64(int8(format)), nil
}
switch format {
case formatFloat32:
v, err := d.readFloat32()
return float64(v), err
case formatFloat64:
return d.readFloat64()
case formatUint8:
v, err := d.readUint8()
return float64(v), err
case formatUint16:
v, err := d.readUint16()
return float64(v), err
case formatUint32:
v, err := d.readUint32()
return float64(v), err
case formatInt8:
v, err := d.readInt8()
return float64(v), err
case formatInt16:
v, err := d.readInt16()
return float64(v), err
case formatInt32:
v, err := d.readInt32()
return float64(v), err
case formatInt64:
v, err := d.readInt64()
return float64(v), err
default:
return 0, ErrTypeMismatch
}
}