-
Notifications
You must be signed in to change notification settings - Fork 1.6k
/
internal.dart
1029 lines (972 loc) · 31.5 KB
/
internal.dart
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 (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
library dart._internal;
import 'dart:collection';
import 'dart:async'
show
Future,
Stream,
StreamSubscription,
StreamTransformer,
StreamTransformerBase,
Zone;
import 'dart:convert' show Converter;
import 'dart:core' hide Symbol;
import 'dart:core' as core show Symbol;
import 'dart:math' show Random;
import 'dart:typed_data' show Uint8List;
part 'async_cast.dart';
part 'bytes_builder.dart';
part 'cast.dart';
part 'errors.dart';
part 'iterable.dart';
part 'list.dart';
part 'linked_list.dart';
part 'print.dart';
part 'sort.dart';
part 'symbol.dart';
// Returns true iff `null as T` will succeed based on the
// execution mode.
external bool typeAcceptsNull<T>();
/// Unsafely treats [value] as type [T].
///
/// An unsafe cast allows casting any value to any type,
/// without any runtime type checks.
///
/// Can be used internally in platform library implementations of
/// data structures, where a value is known to have a type different
/// from its static type (like knowing that a string is definitely
/// a "_OneByteString" or that the value stored into a heterogeneous
/// list is really a value of the surrounding map).
///
/// Must only be used for casts which would definitely *succeed*
/// as a normal cast.
///
/// Should only be used for performance in performance critical code.
external T unsafeCast<T>(dynamic value);
// Powers of 10 up to 10^22 are representable as doubles.
// Powers of 10 above that are only approximate due to lack of precision.
// Used by double-parsing.
const POWERS_OF_TEN = const [
1.0, // 0
10.0,
100.0,
1000.0,
10000.0,
100000.0, // 5
1000000.0,
10000000.0,
100000000.0,
1000000000.0,
10000000000.0, // 10
100000000000.0,
1000000000000.0,
10000000000000.0,
100000000000000.0,
1000000000000000.0, // 15
10000000000000000.0,
100000000000000000.0,
1000000000000000000.0,
10000000000000000000.0,
100000000000000000000.0, // 20
1000000000000000000000.0,
10000000000000000000000.0,
];
/**
* An [Iterable] of the UTF-16 code units of a [String] in index order.
*/
class CodeUnits extends UnmodifiableListBase<int> {
/** The string that this is the code units of. */
final String _string;
CodeUnits(this._string);
int get length => _string.length;
int operator [](int i) => _string.codeUnitAt(i);
static String stringOf(CodeUnits u) => u._string;
}
/// Marks a function or library as having an external implementation ("native"
/// in the Dart VM).
///
/// On a function, this provides a backend-specific String that can be used to
/// identify the function's implementation.
///
/// On a library, it provides a Uri that can be used to locate the native
/// library's implementation.
class ExternalName {
final String name;
const ExternalName(this.name);
}
// Shared hex-parsing utilities.
/// Parses a single hex-digit as code unit.
///
/// Returns a negative value if the character is not a valid hex-digit.
int hexDigitValue(int char) {
assert(char >= 0 && char <= 0xFFFF);
const int digit0 = 0x30;
const int a = 0x61;
const int f = 0x66;
int digit = char ^ digit0;
if (digit <= 9) return digit;
int letter = (char | 0x20);
if (a <= letter && letter <= f) return letter - (a - 10);
return -1;
}
/// Parses two hex digits in a string.
///
/// Returns a negative value if either digit isn't valid.
int parseHexByte(String source, int index) {
assert(index + 2 <= source.length);
int digit1 = hexDigitValue(source.codeUnitAt(index));
int digit2 = hexDigitValue(source.codeUnitAt(index + 1));
return digit1 * 16 + digit2 - (digit2 & 256);
}
/// A reusable `null`-valued future used by `dart:async`.
///
/// **DO NOT USE.**
///
/// This future is used in situations where a future is expected,
/// but no asynchronous computation actually happens,
/// like cancelling a stream from a controller with no `onCancel` callback.
/// *Some code depends on recognizing this future in order to react
/// synchronously.*
/// It does so to avoid changing event interleaving during the null safety
/// migration where, for example, the [StreamSubscription.cancel] method
/// stopped being able to return `null`.
/// The code that would be broken by such a timing change is fragile,
/// but we are not able to simply change it.
/// For better or worse, code depends on the precise timing that our libraries
/// have so far exhibited.
///
/// This future will be removed again if we can ever do so.
/// Do not use it for anything other than preserving timing
/// during the null safety migration.
final Future<Null> nullFuture = Zone.root.run(() => Future<Null>.value(null));
/// A default hash function used by the platform in various places.
///
/// This is currently the [Jenkins hash function][1] but using masking to keep
/// values in SMI range.
///
/// [1]: http://en.wikipedia.org/wiki/Jenkins_hash_function
///
/// Use:
/// Hash each value with the hash of the previous value, then get the final
/// hash by calling finish.
/// ```
/// var hash = 0;
/// for (var value in values) {
/// hash = SystemHash.combine(hash, value.hashCode);
/// }
/// hash = SystemHash.finish(hash);
/// ```
///
/// TODO(lrn): Consider specializing this code per platform,
/// so the VM can use its 64-bit integers directly.
@Since("2.11")
class SystemHash {
static int combine(int hash, int value) {
hash = 0x1fffffff & (hash + value);
hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
return hash ^ (hash >> 6);
}
static int finish(int hash) {
hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
hash = hash ^ (hash >> 11);
return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
}
static int hash2(int v1, int v2, [@Since("2.14") int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
return finish(hash);
}
static int hash3(int v1, int v2, int v3, [@Since("2.14") int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
return finish(hash);
}
static int hash4(int v1, int v2, int v3, int v4,
[@Since("2.14") int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
return finish(hash);
}
static int hash5(int v1, int v2, int v3, int v4, int v5,
[@Since("2.14") int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
return finish(hash);
}
static int hash6(int v1, int v2, int v3, int v4, int v5, int v6,
[@Since("2.14") int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
return finish(hash);
}
static int hash7(int v1, int v2, int v3, int v4, int v5, int v6, int v7,
[@Since("2.14") int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
return finish(hash);
}
static int hash8(
int v1, int v2, int v3, int v4, int v5, int v6, int v7, int v8,
[@Since("2.14") int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
return finish(hash);
}
static int hash9(
int v1, int v2, int v3, int v4, int v5, int v6, int v7, int v8, int v9,
[@Since("2.14") int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
return finish(hash);
}
static int hash10(int v1, int v2, int v3, int v4, int v5, int v6, int v7,
int v8, int v9, int v10,
[@Since("2.14") int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
hash = combine(hash, v10);
return finish(hash);
}
@Since("2.14")
static int hash11(int v1, int v2, int v3, int v4, int v5, int v6, int v7,
int v8, int v9, int v10, int v11,
[int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
hash = combine(hash, v10);
hash = combine(hash, v11);
return finish(hash);
}
@Since("2.14")
static int hash12(int v1, int v2, int v3, int v4, int v5, int v6, int v7,
int v8, int v9, int v10, int v11, int v12,
[int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
hash = combine(hash, v10);
hash = combine(hash, v11);
hash = combine(hash, v12);
return finish(hash);
}
@Since("2.14")
static int hash13(int v1, int v2, int v3, int v4, int v5, int v6, int v7,
int v8, int v9, int v10, int v11, int v12, int v13,
[int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
hash = combine(hash, v10);
hash = combine(hash, v11);
hash = combine(hash, v12);
hash = combine(hash, v13);
return finish(hash);
}
@Since("2.14")
static int hash14(int v1, int v2, int v3, int v4, int v5, int v6, int v7,
int v8, int v9, int v10, int v11, int v12, int v13, int v14,
[int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
hash = combine(hash, v10);
hash = combine(hash, v11);
hash = combine(hash, v12);
hash = combine(hash, v13);
hash = combine(hash, v14);
return finish(hash);
}
@Since("2.14")
static int hash15(int v1, int v2, int v3, int v4, int v5, int v6, int v7,
int v8, int v9, int v10, int v11, int v12, int v13, int v14, int v15,
[int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
hash = combine(hash, v10);
hash = combine(hash, v11);
hash = combine(hash, v12);
hash = combine(hash, v13);
hash = combine(hash, v14);
hash = combine(hash, v15);
return finish(hash);
}
@Since("2.14")
static int hash16(
int v1,
int v2,
int v3,
int v4,
int v5,
int v6,
int v7,
int v8,
int v9,
int v10,
int v11,
int v12,
int v13,
int v14,
int v15,
int v16,
[int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
hash = combine(hash, v10);
hash = combine(hash, v11);
hash = combine(hash, v12);
hash = combine(hash, v13);
hash = combine(hash, v14);
hash = combine(hash, v15);
hash = combine(hash, v16);
return finish(hash);
}
@Since("2.14")
static int hash17(
int v1,
int v2,
int v3,
int v4,
int v5,
int v6,
int v7,
int v8,
int v9,
int v10,
int v11,
int v12,
int v13,
int v14,
int v15,
int v16,
int v17,
[int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
hash = combine(hash, v10);
hash = combine(hash, v11);
hash = combine(hash, v12);
hash = combine(hash, v13);
hash = combine(hash, v14);
hash = combine(hash, v15);
hash = combine(hash, v16);
hash = combine(hash, v17);
return finish(hash);
}
@Since("2.14")
static int hash18(
int v1,
int v2,
int v3,
int v4,
int v5,
int v6,
int v7,
int v8,
int v9,
int v10,
int v11,
int v12,
int v13,
int v14,
int v15,
int v16,
int v17,
int v18,
[int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
hash = combine(hash, v10);
hash = combine(hash, v11);
hash = combine(hash, v12);
hash = combine(hash, v13);
hash = combine(hash, v14);
hash = combine(hash, v15);
hash = combine(hash, v16);
hash = combine(hash, v17);
hash = combine(hash, v18);
return finish(hash);
}
@Since("2.14")
static int hash19(
int v1,
int v2,
int v3,
int v4,
int v5,
int v6,
int v7,
int v8,
int v9,
int v10,
int v11,
int v12,
int v13,
int v14,
int v15,
int v16,
int v17,
int v18,
int v19,
[int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
hash = combine(hash, v10);
hash = combine(hash, v11);
hash = combine(hash, v12);
hash = combine(hash, v13);
hash = combine(hash, v14);
hash = combine(hash, v15);
hash = combine(hash, v16);
hash = combine(hash, v17);
hash = combine(hash, v18);
hash = combine(hash, v19);
return finish(hash);
}
@Since("2.14")
static int hash20(
int v1,
int v2,
int v3,
int v4,
int v5,
int v6,
int v7,
int v8,
int v9,
int v10,
int v11,
int v12,
int v13,
int v14,
int v15,
int v16,
int v17,
int v18,
int v19,
int v20,
[int seed = 0]) {
int hash = seed;
hash = combine(hash, v1);
hash = combine(hash, v2);
hash = combine(hash, v3);
hash = combine(hash, v4);
hash = combine(hash, v5);
hash = combine(hash, v6);
hash = combine(hash, v7);
hash = combine(hash, v8);
hash = combine(hash, v9);
hash = combine(hash, v10);
hash = combine(hash, v11);
hash = combine(hash, v12);
hash = combine(hash, v13);
hash = combine(hash, v14);
hash = combine(hash, v15);
hash = combine(hash, v16);
hash = combine(hash, v17);
hash = combine(hash, v18);
hash = combine(hash, v19);
hash = combine(hash, v20);
return finish(hash);
}
/// Bit shuffling operation to improve hash codes.
///
/// Dart integers have very simple hash codes (their value),
/// which is acceptable for the hash above because it smears the bits
/// as part of the combination.
/// However, for the unordered hash, we need to improve
/// the hash code of, e.g., integers, to avoid collections of small integers
/// too easily having colliding hash results.
///
/// Assumes the input hash code is an unsigned 32-bit integer.
/// Found by Christopher Wellons [https://github.com/skeeto/hash-prospector].
static int smear(int x) {
// TODO: Use >>> instead of >> when available.
x ^= x >> 16;
x = (x * 0x7feb352d) & 0xFFFFFFFF;
x ^= x >> 15;
x = (x * 0x846ca68b) & 0xFFFFFFFF;
x ^= x >> 16;
return x;
}
}
/// Sentinel values that should never be exposed outside of platform libraries.
@Since("2.14")
class SentinelValue {
final int id;
const SentinelValue(this.id);
}
/// A default value to use when only one sentinel is needed.
@Since("2.14")
const Object sentinelValue = const SentinelValue(0);
/// Given an [instance] of some generic type [T], and [extract], a first-class
/// generic function that takes the same number of type parameters as [T],
/// invokes the function with the same type arguments that were passed to T
/// when [instance] was constructed.
///
/// Example:
///
/// ```dart template:top
/// class Two<A, B> {}
///
/// print(extractTypeArguments<List>(<int>[], <T>() => new Set<T>()));
/// // Prints: Instance of 'Set<int>'.
///
/// print(extractTypeArguments<Map>(<String, bool>{},
/// <T, S>() => new Two<T, S>));
/// // Prints: Instance of 'Two<String, bool>'.
/// ```
///
/// The type argument T is important to choose which specific type parameter
/// list in [instance]'s type hierarchy is being extracted. Consider:
///
/// ```dart template:top
/// class A<T> {}
/// class B<T> {}
///
/// class C implements A<int>, B<String> {}
///
/// main() {
/// var c = new C();
/// print(extractTypeArguments<A>(c, <T>() => <T>[]));
/// // Prints: Instance of 'List<int>'.
///
/// print(extractTypeArguments<B>(c, <T>() => <T>[]));
/// // Prints: Instance of 'List<String>'.
/// }
/// ```
///
/// A caller must not:
///
/// * Pass `null` for [instance].
/// * Use a non-class type (i.e. a function type) for [T].
/// * Use a non-generic type for [T].
/// * Pass an instance of a generic type and a function that don't both take
/// the same number of type arguments:
///
/// ```dart
/// extractTypeArguments<List>(<int>[], <T, S>() => null);
/// ```
///
/// See this issue for more context:
/// https://github.com/dart-lang/sdk/issues/31371
external Object? extractTypeArguments<T>(T instance, Function extract);
/// Annotation class marking the version where SDK API was added.
///
/// A `Since` annotation can be applied to a library declaration,
/// any public declaration in a library, or in a class, or to
/// an optional parameter.
///
/// It signifies that the export, member or parameter was *added* in
/// that version.
///
/// When applied to a library declaration, it also a applies to
/// all members declared or exported by that library.
/// If applied to a class, it also applies to all members and constructors
/// of that class.
/// If applied to a class method, or parameter of such,
/// any method implementing that interface method is also annotated.
/// If multiple `Since` annotations apply to the same declaration or
/// parameter, the latest version takes precedence.
///
/// Any use of a marked API may trigger a warning if the using code
/// does not require an SDK version guaranteeing that the API is available,
/// unless the API feature is also provided by something else.
/// It is only a problem if an annotated feature is used, and the annotated
/// API is the *only* thing providing the functionality.
/// For example, using `Future` exported by `dart:core` is not a problem
/// if the same library also imports `dart:async`, and using an optional
/// parameter on an interface is not a problem if the same type also
/// implements another interface providing the same parameter.
///
/// The version must be a semantic version (like `1.4.2` or `0.9.4-rec.4`),
/// or the first two numbers of a semantic version (like `1.0` or `2.2`),
/// representing a stable release, and equivalent to the semantic version
/// you get by appending a `.0`.
@Since("2.2")
class Since {
final String version;
const Since(this.version);
}
/// A null-check function for function parameters in Null Safety enabled code.
///
/// Because Dart does not have full null safety
/// until all legacy code has been removed from a program,
/// a non-nullable parameter can still end up with a `null` value.
/// This function can be used to guard those functions against null arguments.
/// It throws a [TypeError] because we are really seeing the failure to
/// assign `null` to a non-nullable type.
///
/// See http://dartbug.com/40614 for context.
T checkNotNullable<T extends Object>(T value, String name) {
if ((value as dynamic) == null) {
throw NotNullableError<T>(name);
}
return value;
}
/// A [TypeError] thrown by [checkNotNullable].
class NotNullableError<T> extends Error implements TypeError {
final String _name;
NotNullableError(this._name);
String toString() => "Null is not a valid value for '$_name' of type '$T'";
}
/// A function that returns the value or default value (if invoked with `null`
/// value) for non-nullable function parameters in Null safety enabled code.
///
/// Because Dart does not have full null safety
/// until all legacy code has been removed from a program,
/// a non-nullable parameter can still end up with a `null` value.
/// This function can be used to get a default value for a parameter
/// when a `null` value is passed in for a non-nullable parameter.
///
/// TODO(40810) - Remove uses of this function when Dart has full null safety.
T valueOfNonNullableParamWithDefault<T extends Object>(T value, T defaultVal) {
if ((value as dynamic) == null) {
return defaultVal;
} else {
return value;
}
}
/**
* HTTP status codes. Exported in dart:io and dart:html.
*/
abstract class HttpStatus {
static const int continue_ = 100;
static const int switchingProtocols = 101;
@Since("2.1")
static const int processing = 102;
static const int ok = 200;
static const int created = 201;
static const int accepted = 202;
static const int nonAuthoritativeInformation = 203;
static const int noContent = 204;
static const int resetContent = 205;
static const int partialContent = 206;
@Since("2.1")
static const int multiStatus = 207;
@Since("2.1")
static const int alreadyReported = 208;
@Since("2.1")
static const int imUsed = 226;
static const int multipleChoices = 300;
static const int movedPermanently = 301;
static const int found = 302;
static const int movedTemporarily = 302; // Common alias for found.
static const int seeOther = 303;
static const int notModified = 304;
static const int useProxy = 305;
static const int temporaryRedirect = 307;
@Since("2.1")
static const int permanentRedirect = 308;
static const int badRequest = 400;
static const int unauthorized = 401;
static const int paymentRequired = 402;
static const int forbidden = 403;
static const int notFound = 404;
static const int methodNotAllowed = 405;
static const int notAcceptable = 406;
static const int proxyAuthenticationRequired = 407;
static const int requestTimeout = 408;
static const int conflict = 409;
static const int gone = 410;
static const int lengthRequired = 411;
static const int preconditionFailed = 412;
static const int requestEntityTooLarge = 413;
static const int requestUriTooLong = 414;
static const int unsupportedMediaType = 415;
static const int requestedRangeNotSatisfiable = 416;
static const int expectationFailed = 417;
@Since("2.1")
static const int misdirectedRequest = 421;
@Since("2.1")
static const int unprocessableEntity = 422;
@Since("2.1")
static const int locked = 423;
@Since("2.1")
static const int failedDependency = 424;
static const int upgradeRequired = 426;
@Since("2.1")
static const int preconditionRequired = 428;
@Since("2.1")
static const int tooManyRequests = 429;
@Since("2.1")
static const int requestHeaderFieldsTooLarge = 431;
@Since("2.1")
static const int connectionClosedWithoutResponse = 444;
@Since("2.1")
static const int unavailableForLegalReasons = 451;
@Since("2.1")
static const int clientClosedRequest = 499;
static const int internalServerError = 500;
static const int notImplemented = 501;
static const int badGateway = 502;
static const int serviceUnavailable = 503;
static const int gatewayTimeout = 504;
static const int httpVersionNotSupported = 505;
@Since("2.1")
static const int variantAlsoNegotiates = 506;
@Since("2.1")
static const int insufficientStorage = 507;
@Since("2.1")
static const int loopDetected = 508;
@Since("2.1")
static const int notExtended = 510;
@Since("2.1")
static const int networkAuthenticationRequired = 511;
// Client generated status code.
static const int networkConnectTimeoutError = 599;
@Deprecated("Use continue_ instead")
static const int CONTINUE = continue_;
@Deprecated("Use switchingProtocols instead")
static const int SWITCHING_PROTOCOLS = switchingProtocols;
@Deprecated("Use ok instead")
static const int OK = ok;
@Deprecated("Use created instead")
static const int CREATED = created;
@Deprecated("Use accepted instead")
static const int ACCEPTED = accepted;
@Deprecated("Use nonAuthoritativeInformation instead")
static const int NON_AUTHORITATIVE_INFORMATION = nonAuthoritativeInformation;
@Deprecated("Use noContent instead")
static const int NO_CONTENT = noContent;
@Deprecated("Use resetContent instead")
static const int RESET_CONTENT = resetContent;
@Deprecated("Use partialContent instead")
static const int PARTIAL_CONTENT = partialContent;
@Deprecated("Use multipleChoices instead")
static const int MULTIPLE_CHOICES = multipleChoices;
@Deprecated("Use movedPermanently instead")
static const int MOVED_PERMANENTLY = movedPermanently;
@Deprecated("Use found instead")
static const int FOUND = found;
@Deprecated("Use movedTemporarily instead")
static const int MOVED_TEMPORARILY = movedTemporarily;
@Deprecated("Use seeOther instead")
static const int SEE_OTHER = seeOther;
@Deprecated("Use notModified instead")
static const int NOT_MODIFIED = notModified;
@Deprecated("Use useProxy instead")
static const int USE_PROXY = useProxy;
@Deprecated("Use temporaryRedirect instead")
static const int TEMPORARY_REDIRECT = temporaryRedirect;
@Deprecated("Use badRequest instead")
static const int BAD_REQUEST = badRequest;
@Deprecated("Use unauthorized instead")
static const int UNAUTHORIZED = unauthorized;
@Deprecated("Use paymentRequired instead")
static const int PAYMENT_REQUIRED = paymentRequired;
@Deprecated("Use forbidden instead")
static const int FORBIDDEN = forbidden;
@Deprecated("Use notFound instead")
static const int NOT_FOUND = notFound;
@Deprecated("Use methodNotAllowed instead")
static const int METHOD_NOT_ALLOWED = methodNotAllowed;
@Deprecated("Use notAcceptable instead")
static const int NOT_ACCEPTABLE = notAcceptable;
@Deprecated("Use proxyAuthenticationRequired instead")
static const int PROXY_AUTHENTICATION_REQUIRED = proxyAuthenticationRequired;
@Deprecated("Use requestTimeout instead")
static const int REQUEST_TIMEOUT = requestTimeout;
@Deprecated("Use conflict instead")
static const int CONFLICT = conflict;
@Deprecated("Use gone instead")
static const int GONE = gone;
@Deprecated("Use lengthRequired instead")
static const int LENGTH_REQUIRED = lengthRequired;
@Deprecated("Use preconditionFailed instead")
static const int PRECONDITION_FAILED = preconditionFailed;
@Deprecated("Use requestEntityTooLarge instead")
static const int REQUEST_ENTITY_TOO_LARGE = requestEntityTooLarge;
@Deprecated("Use requestUriTooLong instead")
static const int REQUEST_URI_TOO_LONG = requestUriTooLong;
@Deprecated("Use unsupportedMediaType instead")
static const int UNSUPPORTED_MEDIA_TYPE = unsupportedMediaType;
@Deprecated("Use requestedRangeNotSatisfiable instead")
static const int REQUESTED_RANGE_NOT_SATISFIABLE =
requestedRangeNotSatisfiable;
@Deprecated("Use expectationFailed instead")
static const int EXPECTATION_FAILED = expectationFailed;
@Deprecated("Use upgradeRequired instead")
static const int UPGRADE_REQUIRED = upgradeRequired;
@Deprecated("Use internalServerError instead")
static const int INTERNAL_SERVER_ERROR = internalServerError;
@Deprecated("Use notImplemented instead")
static const int NOT_IMPLEMENTED = notImplemented;
@Deprecated("Use badGateway instead")
static const int BAD_GATEWAY = badGateway;
@Deprecated("Use serviceUnavailable instead")
static const int SERVICE_UNAVAILABLE = serviceUnavailable;
@Deprecated("Use gatewayTimeout instead")
static const int GATEWAY_TIMEOUT = gatewayTimeout;
@Deprecated("Use httpVersionNotSupported instead")
static const int HTTP_VERSION_NOT_SUPPORTED = httpVersionNotSupported;
@Deprecated("Use networkConnectTimeoutError instead")
static const int NETWORK_CONNECT_TIMEOUT_ERROR = networkConnectTimeoutError;
}
// Class moved here from dart:collection
// to allow another, more important, class to implement the interface
// without having to match the private members.
/// An entry in a doubly linked list.
///
/// Such an entry contains an element and a link to the previous or next
/// entries, if any.
//
// This class should have been abstract, but originally wasn't.
// It's not used itself to interact with the double linked queue class,
// which uses the `_DoubleLinkedQueueEntry` class and subclasses instead.
// It's only used as an interface for the
// `DoubleLinkedQueue.forEach`, `DoubleLinkedQueue.firstEntry` and
// `DoubleLinkedQueue.lastEntry` members.
// Still, someone might have based their own double-linked list on this
// class, so we keep it functional.
class DoubleLinkedQueueEntry<E> {
DoubleLinkedQueueEntry<E>? _previousLink;
DoubleLinkedQueueEntry<E>? _nextLink;
/// The element of the entry in the queue.
E element;
/// Creates a new entry with the given [element].
DoubleLinkedQueueEntry(this.element);
void _link(
DoubleLinkedQueueEntry<E>? previous, DoubleLinkedQueueEntry<E>? next) {
_nextLink = next;
_previousLink = previous;
previous?._nextLink = this;
next?._previousLink = this;