-
Notifications
You must be signed in to change notification settings - Fork 17.9k
/
Copy pathbinary.go
1036 lines (931 loc) · 24.3 KB
/
binary.go
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
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package binary implements simple translation between numbers and byte
// sequences and encoding and decoding of varints.
//
// Numbers are translated by reading and writing fixed-size values.
// A fixed-size value is either a fixed-size arithmetic
// type (bool, int8, uint8, int16, float32, complex64, ...)
// or an array or struct containing only fixed-size values.
//
// The varint functions encode and decode single integer values using
// a variable-length encoding; smaller values require fewer bytes.
// For a specification, see
// https://developers.google.com/protocol-buffers/docs/encoding.
//
// This package favors simplicity over efficiency. Clients that require
// high-performance serialization, especially for large data structures,
// should look at more advanced solutions such as the [encoding/gob]
// package or [google.golang.org/protobuf] for protocol buffers.
package binary
import (
"errors"
"io"
"math"
"reflect"
"slices"
"sync"
)
var errBufferTooSmall = errors.New("buffer too small")
// A ByteOrder specifies how to convert byte slices into
// 16-, 32-, or 64-bit unsigned integers.
//
// It is implemented by [LittleEndian], [BigEndian], and [NativeEndian].
type ByteOrder interface {
Uint16([]byte) uint16
Uint32([]byte) uint32
Uint64([]byte) uint64
PutUint16([]byte, uint16)
PutUint32([]byte, uint32)
PutUint64([]byte, uint64)
String() string
}
// AppendByteOrder specifies how to append 16-, 32-, or 64-bit unsigned integers
// into a byte slice.
//
// It is implemented by [LittleEndian], [BigEndian], and [NativeEndian].
type AppendByteOrder interface {
AppendUint16([]byte, uint16) []byte
AppendUint32([]byte, uint32) []byte
AppendUint64([]byte, uint64) []byte
String() string
}
// LittleEndian is the little-endian implementation of [ByteOrder] and [AppendByteOrder].
var LittleEndian littleEndian
// BigEndian is the big-endian implementation of [ByteOrder] and [AppendByteOrder].
var BigEndian bigEndian
type littleEndian struct{}
// Uint16 returns the uint16 representation of b[0:2].
func (littleEndian) Uint16(b []byte) uint16 {
_ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
return uint16(b[0]) | uint16(b[1])<<8
}
// PutUint16 stores v into b[0:2].
func (littleEndian) PutUint16(b []byte, v uint16) {
_ = b[1] // early bounds check to guarantee safety of writes below
b[0] = byte(v)
b[1] = byte(v >> 8)
}
// AppendUint16 appends the bytes of v to b and returns the appended slice.
func (littleEndian) AppendUint16(b []byte, v uint16) []byte {
return append(b,
byte(v),
byte(v>>8),
)
}
// Uint32 returns the uint32 representation of b[0:4].
func (littleEndian) Uint32(b []byte) uint32 {
_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
}
// PutUint32 stores v into b[0:4].
func (littleEndian) PutUint32(b []byte, v uint32) {
_ = b[3] // early bounds check to guarantee safety of writes below
b[0] = byte(v)
b[1] = byte(v >> 8)
b[2] = byte(v >> 16)
b[3] = byte(v >> 24)
}
// AppendUint32 appends the bytes of v to b and returns the appended slice.
func (littleEndian) AppendUint32(b []byte, v uint32) []byte {
return append(b,
byte(v),
byte(v>>8),
byte(v>>16),
byte(v>>24),
)
}
// Uint64 returns the uint64 representation of b[0:8].
func (littleEndian) Uint64(b []byte) uint64 {
_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
}
// PutUint64 stores v into b[0:8].
func (littleEndian) PutUint64(b []byte, v uint64) {
_ = b[7] // early bounds check to guarantee safety of writes below
b[0] = byte(v)
b[1] = byte(v >> 8)
b[2] = byte(v >> 16)
b[3] = byte(v >> 24)
b[4] = byte(v >> 32)
b[5] = byte(v >> 40)
b[6] = byte(v >> 48)
b[7] = byte(v >> 56)
}
// AppendUint64 appends the bytes of v to b and returns the appended slice.
func (littleEndian) AppendUint64(b []byte, v uint64) []byte {
return append(b,
byte(v),
byte(v>>8),
byte(v>>16),
byte(v>>24),
byte(v>>32),
byte(v>>40),
byte(v>>48),
byte(v>>56),
)
}
func (littleEndian) String() string { return "LittleEndian" }
func (littleEndian) GoString() string { return "binary.LittleEndian" }
type bigEndian struct{}
// Uint16 returns the uint16 representation of b[0:2].
func (bigEndian) Uint16(b []byte) uint16 {
_ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
return uint16(b[1]) | uint16(b[0])<<8
}
// PutUint16 stores v into b[0:2].
func (bigEndian) PutUint16(b []byte, v uint16) {
_ = b[1] // early bounds check to guarantee safety of writes below
b[0] = byte(v >> 8)
b[1] = byte(v)
}
// AppendUint16 appends the bytes of v to b and returns the appended slice.
func (bigEndian) AppendUint16(b []byte, v uint16) []byte {
return append(b,
byte(v>>8),
byte(v),
)
}
// Uint32 returns the uint32 representation of b[0:4].
func (bigEndian) Uint32(b []byte) uint32 {
_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
return uint32(b[3]) | uint32(b[2])<<8 | uint32(b[1])<<16 | uint32(b[0])<<24
}
// PutUint32 stores v into b[0:4].
func (bigEndian) PutUint32(b []byte, v uint32) {
_ = b[3] // early bounds check to guarantee safety of writes below
b[0] = byte(v >> 24)
b[1] = byte(v >> 16)
b[2] = byte(v >> 8)
b[3] = byte(v)
}
// AppendUint32 appends the bytes of v to b and returns the appended slice.
func (bigEndian) AppendUint32(b []byte, v uint32) []byte {
return append(b,
byte(v>>24),
byte(v>>16),
byte(v>>8),
byte(v),
)
}
// Uint64 returns the uint64 representation of b[0:8].
func (bigEndian) Uint64(b []byte) uint64 {
_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 |
uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56
}
// PutUint64 stores v into b[0:8].
func (bigEndian) PutUint64(b []byte, v uint64) {
_ = b[7] // early bounds check to guarantee safety of writes below
b[0] = byte(v >> 56)
b[1] = byte(v >> 48)
b[2] = byte(v >> 40)
b[3] = byte(v >> 32)
b[4] = byte(v >> 24)
b[5] = byte(v >> 16)
b[6] = byte(v >> 8)
b[7] = byte(v)
}
// AppendUint64 appends the bytes of v to b and returns the appended slice.
func (bigEndian) AppendUint64(b []byte, v uint64) []byte {
return append(b,
byte(v>>56),
byte(v>>48),
byte(v>>40),
byte(v>>32),
byte(v>>24),
byte(v>>16),
byte(v>>8),
byte(v),
)
}
func (bigEndian) String() string { return "BigEndian" }
func (bigEndian) GoString() string { return "binary.BigEndian" }
func (nativeEndian) String() string { return "NativeEndian" }
func (nativeEndian) GoString() string { return "binary.NativeEndian" }
// Read reads structured binary data from r into data.
// Data must be a pointer to a fixed-size value or a slice
// of fixed-size values.
// Bytes read from r are decoded using the specified byte order
// and written to successive fields of the data.
// When decoding boolean values, a zero byte is decoded as false, and
// any other non-zero byte is decoded as true.
// When reading into structs, the field data for fields with
// blank (_) field names is skipped; i.e., blank field names
// may be used for padding.
// When reading into a struct, all non-blank fields must be exported
// or Read may panic.
//
// The error is [io.EOF] only if no bytes were read.
// If an [io.EOF] happens after reading some but not all the bytes,
// Read returns [io.ErrUnexpectedEOF].
func Read(r io.Reader, order ByteOrder, data any) error {
// Fast path for basic types and slices.
if n, _ := intDataSize(data); n != 0 {
bs := make([]byte, n)
if _, err := io.ReadFull(r, bs); err != nil {
return err
}
if decodeFast(bs, order, data) {
return nil
}
}
// Fallback to reflect-based decoding.
v := reflect.ValueOf(data)
size := -1
switch v.Kind() {
case reflect.Pointer:
v = v.Elem()
size = dataSize(v)
case reflect.Slice:
size = dataSize(v)
}
if size < 0 {
return errors.New("binary.Read: invalid type " + reflect.TypeOf(data).String())
}
d := &decoder{order: order, buf: make([]byte, size)}
if _, err := io.ReadFull(r, d.buf); err != nil {
return err
}
d.value(v)
return nil
}
// Decode decodes binary data from buf into data according to
// the given byte order.
// It returns an error if buf is too small, otherwise the number of
// bytes consumed from buf.
func Decode(buf []byte, order ByteOrder, data any) (int, error) {
if n, _ := intDataSize(data); n != 0 {
if len(buf) < n {
return 0, errBufferTooSmall
}
if decodeFast(buf, order, data) {
return n, nil
}
}
// Fallback to reflect-based decoding.
v := reflect.ValueOf(data)
size := -1
switch v.Kind() {
case reflect.Pointer:
v = v.Elem()
size = dataSize(v)
case reflect.Slice:
size = dataSize(v)
}
if size < 0 {
return 0, errors.New("binary.Decode: invalid type " + reflect.TypeOf(data).String())
}
if len(buf) < size {
return 0, errBufferTooSmall
}
d := &decoder{order: order, buf: buf[:size]}
d.value(v)
return size, nil
}
func decodeFast(bs []byte, order ByteOrder, data any) bool {
switch data := data.(type) {
case *bool:
*data = bs[0] != 0
case *int8:
*data = int8(bs[0])
case *uint8:
*data = bs[0]
case *int16:
*data = int16(order.Uint16(bs))
case *uint16:
*data = order.Uint16(bs)
case *int32:
*data = int32(order.Uint32(bs))
case *uint32:
*data = order.Uint32(bs)
case *int64:
*data = int64(order.Uint64(bs))
case *uint64:
*data = order.Uint64(bs)
case *float32:
*data = math.Float32frombits(order.Uint32(bs))
case *float64:
*data = math.Float64frombits(order.Uint64(bs))
case []bool:
for i, x := range bs { // Easier to loop over the input for 8-bit values.
data[i] = x != 0
}
case []int8:
for i, x := range bs {
data[i] = int8(x)
}
case []uint8:
copy(data, bs)
case []int16:
for i := range data {
data[i] = int16(order.Uint16(bs[2*i:]))
}
case []uint16:
for i := range data {
data[i] = order.Uint16(bs[2*i:])
}
case []int32:
for i := range data {
data[i] = int32(order.Uint32(bs[4*i:]))
}
case []uint32:
for i := range data {
data[i] = order.Uint32(bs[4*i:])
}
case []int64:
for i := range data {
data[i] = int64(order.Uint64(bs[8*i:]))
}
case []uint64:
for i := range data {
data[i] = order.Uint64(bs[8*i:])
}
case []float32:
for i := range data {
data[i] = math.Float32frombits(order.Uint32(bs[4*i:]))
}
case []float64:
for i := range data {
data[i] = math.Float64frombits(order.Uint64(bs[8*i:]))
}
default:
return false
}
return true
}
// Write writes the binary representation of data into w.
// Data must be a fixed-size value or a slice of fixed-size
// values, or a pointer to such data.
// Boolean values encode as one byte: 1 for true, and 0 for false.
// Bytes written to w are encoded using the specified byte order
// and read from successive fields of the data.
// When writing structs, zero values are written for fields
// with blank (_) field names.
func Write(w io.Writer, order ByteOrder, data any) error {
// Fast path for basic types and slices.
if n, bs := intDataSize(data); n != 0 {
if bs == nil {
bs = make([]byte, n)
encodeFast(bs, order, data)
}
_, err := w.Write(bs)
return err
}
// Fallback to reflect-based encoding.
v := reflect.Indirect(reflect.ValueOf(data))
size := dataSize(v)
if size < 0 {
return errors.New("binary.Write: some values are not fixed-sized in type " + reflect.TypeOf(data).String())
}
buf := make([]byte, size)
e := &encoder{order: order, buf: buf}
e.value(v)
_, err := w.Write(buf)
return err
}
// Encode encodes the binary representation of data into buf according to
// the given byte order.
// It returns an error if buf is too small, otherwise the number of
// bytes written into buf.
func Encode(buf []byte, order ByteOrder, data any) (int, error) {
// Fast path for basic types and slices.
if n, _ := intDataSize(data); n != 0 {
if len(buf) < n {
return 0, errBufferTooSmall
}
encodeFast(buf, order, data)
return n, nil
}
// Fallback to reflect-based encoding.
v := reflect.Indirect(reflect.ValueOf(data))
size := dataSize(v)
if size < 0 {
return 0, errors.New("binary.Encode: some values are not fixed-sized in type " + reflect.TypeOf(data).String())
}
if len(buf) < size {
return 0, errBufferTooSmall
}
e := &encoder{order: order, buf: buf}
e.value(v)
return size, nil
}
// Append appends the binary representation of data to buf.
// buf may be nil, in which case a new buffer will be allocated.
// See [Write] on which data are acceptable.
// It returns the (possibly extended) buffer containing data or an error.
func Append(buf []byte, order ByteOrder, data any) ([]byte, error) {
// Fast path for basic types and slices.
if n, _ := intDataSize(data); n != 0 {
buf, pos := ensure(buf, n)
encodeFast(pos, order, data)
return buf, nil
}
// Fallback to reflect-based encoding.
v := reflect.Indirect(reflect.ValueOf(data))
size := dataSize(v)
if size < 0 {
return nil, errors.New("binary.Append: some values are not fixed-sized in type " + reflect.TypeOf(data).String())
}
buf, pos := ensure(buf, size)
e := &encoder{order: order, buf: pos}
e.value(v)
return buf, nil
}
func encodeFast(bs []byte, order ByteOrder, data any) {
switch v := data.(type) {
case *bool:
if *v {
bs[0] = 1
} else {
bs[0] = 0
}
case bool:
if v {
bs[0] = 1
} else {
bs[0] = 0
}
case []bool:
for i, x := range v {
if x {
bs[i] = 1
} else {
bs[i] = 0
}
}
case *int8:
bs[0] = byte(*v)
case int8:
bs[0] = byte(v)
case []int8:
for i, x := range v {
bs[i] = byte(x)
}
case *uint8:
bs[0] = *v
case uint8:
bs[0] = v
case []uint8:
copy(bs, v)
case *int16:
order.PutUint16(bs, uint16(*v))
case int16:
order.PutUint16(bs, uint16(v))
case []int16:
for i, x := range v {
order.PutUint16(bs[2*i:], uint16(x))
}
case *uint16:
order.PutUint16(bs, *v)
case uint16:
order.PutUint16(bs, v)
case []uint16:
for i, x := range v {
order.PutUint16(bs[2*i:], x)
}
case *int32:
order.PutUint32(bs, uint32(*v))
case int32:
order.PutUint32(bs, uint32(v))
case []int32:
for i, x := range v {
order.PutUint32(bs[4*i:], uint32(x))
}
case *uint32:
order.PutUint32(bs, *v)
case uint32:
order.PutUint32(bs, v)
case []uint32:
for i, x := range v {
order.PutUint32(bs[4*i:], x)
}
case *int64:
order.PutUint64(bs, uint64(*v))
case int64:
order.PutUint64(bs, uint64(v))
case []int64:
for i, x := range v {
order.PutUint64(bs[8*i:], uint64(x))
}
case *uint64:
order.PutUint64(bs, *v)
case uint64:
order.PutUint64(bs, v)
case []uint64:
for i, x := range v {
order.PutUint64(bs[8*i:], x)
}
case *float32:
order.PutUint32(bs, math.Float32bits(*v))
case float32:
order.PutUint32(bs, math.Float32bits(v))
case []float32:
for i, x := range v {
order.PutUint32(bs[4*i:], math.Float32bits(x))
}
case *float64:
order.PutUint64(bs, math.Float64bits(*v))
case float64:
order.PutUint64(bs, math.Float64bits(v))
case []float64:
for i, x := range v {
order.PutUint64(bs[8*i:], math.Float64bits(x))
}
}
}
// Size returns how many bytes [Write] would generate to encode the value v, which
// must be a fixed-size value or a slice of fixed-size values, or a pointer to such data.
// If v is neither of these, Size returns -1.
func Size(v any) int {
switch data := v.(type) {
case bool, int8, uint8:
return 1
case *bool:
if data == nil {
return -1
}
return 1
case *int8:
if data == nil {
return -1
}
return 1
case *uint8:
if data == nil {
return -1
}
return 1
case []bool:
return len(data)
case []int8:
return len(data)
case []uint8:
return len(data)
case int16, uint16:
return 2
case *int16:
if data == nil {
return -1
}
return 2
case *uint16:
if data == nil {
return -1
}
return 2
case []int16:
return 2 * len(data)
case []uint16:
return 2 * len(data)
case int32, uint32:
return 4
case *int32:
if data == nil {
return -1
}
return 4
case *uint32:
if data == nil {
return -1
}
return 4
case []int32:
return 4 * len(data)
case []uint32:
return 4 * len(data)
case int64, uint64:
return 8
case *int64:
if data == nil {
return -1
}
return 8
case *uint64:
if data == nil {
return -1
}
return 8
case []int64:
return 8 * len(data)
case []uint64:
return 8 * len(data)
case float32:
return 4
case *float32:
if data == nil {
return -1
}
return 4
case float64:
return 8
case *float64:
if data == nil {
return -1
}
return 8
case []float32:
return 4 * len(data)
case []float64:
return 8 * len(data)
}
return dataSize(reflect.Indirect(reflect.ValueOf(v)))
}
var structSize sync.Map // map[reflect.Type]int
// dataSize returns the number of bytes the actual data represented by v occupies in memory.
// For compound structures, it sums the sizes of the elements. Thus, for instance, for a slice
// it returns the length of the slice times the element size and does not count the memory
// occupied by the header. If the type of v is not acceptable, dataSize returns -1.
func dataSize(v reflect.Value) int {
switch v.Kind() {
case reflect.Slice, reflect.Array:
t := v.Type().Elem()
if size, ok := structSize.Load(t); ok {
return size.(int) * v.Len()
}
size := sizeof(t)
if size >= 0 {
if t.Kind() == reflect.Struct {
structSize.Store(t, size)
}
return size * v.Len()
}
case reflect.Struct:
t := v.Type()
if size, ok := structSize.Load(t); ok {
return size.(int)
}
size := sizeof(t)
structSize.Store(t, size)
return size
default:
if v.IsValid() {
return sizeof(v.Type())
}
}
return -1
}
// sizeof returns the size >= 0 of variables for the given type or -1 if the type is not acceptable.
func sizeof(t reflect.Type) int {
switch t.Kind() {
case reflect.Array:
if s := sizeof(t.Elem()); s >= 0 {
return s * t.Len()
}
case reflect.Struct:
sum := 0
for i, n := 0, t.NumField(); i < n; i++ {
s := sizeof(t.Field(i).Type)
if s < 0 {
return -1
}
sum += s
}
return sum
case reflect.Bool,
reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
reflect.Float32, reflect.Float64, reflect.Complex64, reflect.Complex128:
return int(t.Size())
}
return -1
}
type coder struct {
order ByteOrder
buf []byte
offset int
}
type decoder coder
type encoder coder
func (d *decoder) bool() bool {
x := d.buf[d.offset]
d.offset++
return x != 0
}
func (e *encoder) bool(x bool) {
if x {
e.buf[e.offset] = 1
} else {
e.buf[e.offset] = 0
}
e.offset++
}
func (d *decoder) uint8() uint8 {
x := d.buf[d.offset]
d.offset++
return x
}
func (e *encoder) uint8(x uint8) {
e.buf[e.offset] = x
e.offset++
}
func (d *decoder) uint16() uint16 {
x := d.order.Uint16(d.buf[d.offset : d.offset+2])
d.offset += 2
return x
}
func (e *encoder) uint16(x uint16) {
e.order.PutUint16(e.buf[e.offset:e.offset+2], x)
e.offset += 2
}
func (d *decoder) uint32() uint32 {
x := d.order.Uint32(d.buf[d.offset : d.offset+4])
d.offset += 4
return x
}
func (e *encoder) uint32(x uint32) {
e.order.PutUint32(e.buf[e.offset:e.offset+4], x)
e.offset += 4
}
func (d *decoder) uint64() uint64 {
x := d.order.Uint64(d.buf[d.offset : d.offset+8])
d.offset += 8
return x
}
func (e *encoder) uint64(x uint64) {
e.order.PutUint64(e.buf[e.offset:e.offset+8], x)
e.offset += 8
}
func (d *decoder) int8() int8 { return int8(d.uint8()) }
func (e *encoder) int8(x int8) { e.uint8(uint8(x)) }
func (d *decoder) int16() int16 { return int16(d.uint16()) }
func (e *encoder) int16(x int16) { e.uint16(uint16(x)) }
func (d *decoder) int32() int32 { return int32(d.uint32()) }
func (e *encoder) int32(x int32) { e.uint32(uint32(x)) }
func (d *decoder) int64() int64 { return int64(d.uint64()) }
func (e *encoder) int64(x int64) { e.uint64(uint64(x)) }
func (d *decoder) value(v reflect.Value) {
switch v.Kind() {
case reflect.Array:
l := v.Len()
for i := 0; i < l; i++ {
d.value(v.Index(i))
}
case reflect.Struct:
t := v.Type()
l := v.NumField()
for i := 0; i < l; i++ {
// Note: Calling v.CanSet() below is an optimization.
// It would be sufficient to check the field name,
// but creating the StructField info for each field is
// costly (run "go test -bench=ReadStruct" and compare
// results when making changes to this code).
if v := v.Field(i); v.CanSet() || t.Field(i).Name != "_" {
d.value(v)
} else {
d.skip(v)
}
}
case reflect.Slice:
l := v.Len()
for i := 0; i < l; i++ {
d.value(v.Index(i))
}
case reflect.Bool:
v.SetBool(d.bool())
case reflect.Int8:
v.SetInt(int64(d.int8()))
case reflect.Int16:
v.SetInt(int64(d.int16()))
case reflect.Int32:
v.SetInt(int64(d.int32()))
case reflect.Int64:
v.SetInt(d.int64())
case reflect.Uint8:
v.SetUint(uint64(d.uint8()))
case reflect.Uint16:
v.SetUint(uint64(d.uint16()))
case reflect.Uint32:
v.SetUint(uint64(d.uint32()))
case reflect.Uint64:
v.SetUint(d.uint64())
case reflect.Float32:
v.SetFloat(float64(math.Float32frombits(d.uint32())))
case reflect.Float64:
v.SetFloat(math.Float64frombits(d.uint64()))
case reflect.Complex64:
v.SetComplex(complex(
float64(math.Float32frombits(d.uint32())),
float64(math.Float32frombits(d.uint32())),
))
case reflect.Complex128:
v.SetComplex(complex(
math.Float64frombits(d.uint64()),
math.Float64frombits(d.uint64()),
))
}
}
func (e *encoder) value(v reflect.Value) {
switch v.Kind() {
case reflect.Array:
l := v.Len()
for i := 0; i < l; i++ {
e.value(v.Index(i))
}
case reflect.Struct:
t := v.Type()
l := v.NumField()
for i := 0; i < l; i++ {
// see comment for corresponding code in decoder.value()
if v := v.Field(i); v.CanSet() || t.Field(i).Name != "_" {
e.value(v)
} else {
e.skip(v)
}
}
case reflect.Slice:
l := v.Len()
for i := 0; i < l; i++ {
e.value(v.Index(i))
}
case reflect.Bool:
e.bool(v.Bool())
case reflect.Int8:
e.int8(int8(v.Int()))
case reflect.Int16:
e.int16(int16(v.Int()))
case reflect.Int32:
e.int32(int32(v.Int()))
case reflect.Int64:
e.int64(v.Int())
case reflect.Uint8:
e.uint8(uint8(v.Uint()))
case reflect.Uint16:
e.uint16(uint16(v.Uint()))
case reflect.Uint32:
e.uint32(uint32(v.Uint()))
case reflect.Uint64:
e.uint64(v.Uint())
case reflect.Float32:
e.uint32(math.Float32bits(float32(v.Float())))
case reflect.Float64:
e.uint64(math.Float64bits(v.Float()))
case reflect.Complex64:
x := v.Complex()
e.uint32(math.Float32bits(float32(real(x))))
e.uint32(math.Float32bits(float32(imag(x))))
case reflect.Complex128:
x := v.Complex()
e.uint64(math.Float64bits(real(x)))
e.uint64(math.Float64bits(imag(x)))
}
}
func (d *decoder) skip(v reflect.Value) {
d.offset += dataSize(v)
}
func (e *encoder) skip(v reflect.Value) {
n := dataSize(v)
clear(e.buf[e.offset : e.offset+n])
e.offset += n
}
// intDataSize returns the size of the data required to represent the data when encoded,
// and optionally a byte slice containing the encoded data if no conversion is necessary.
// It returns zero, nil if the type cannot be implemented by the fast path in Read or Write.
func intDataSize(data any) (int, []byte) {
switch data := data.(type) {
case bool, int8, uint8, *bool, *int8, *uint8:
return 1, nil
case []bool:
return len(data), nil
case []int8:
return len(data), nil
case []uint8:
return len(data), data
case int16, uint16, *int16, *uint16: