-
-
Notifications
You must be signed in to change notification settings - Fork 1.6k
/
slice.cr
1177 lines (1057 loc) · 33.5 KB
/
slice.cr
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
require "c/string"
require "slice/sort"
# A `Slice` is a `Pointer` with an associated size.
#
# While a pointer is unsafe because no bound checks are performed when reading from and writing to it,
# reading from and writing to a slice involve bound checks.
# In this way, a slice is a safe alternative to `Pointer`.
#
# A Slice can be created as read-only: trying to write to it
# will raise. For example the slice of bytes returned by
# `String#to_slice` is read-only.
struct Slice(T)
include Indexable::Mutable(T)
include Comparable(Slice)
# Creates a new `Slice` with the given *args*. The type of the
# slice will be the union of the type of the given *args*.
#
# The slice is allocated on the heap.
#
# ```
# slice = Slice[1, 'a']
# slice[0] # => 1
# slice[1] # => 'a'
# slice.class # => Slice(Char | Int32)
# ```
#
# If `T` is a `Number` then this is equivalent to
# `Number.slice` (numbers will be coerced to the type `T`)
#
# See also: `Number.slice`.
macro [](*args, read_only = false)
# TODO: there should be a better way to check this, probably
# asking if @type was instantiated or if T is defined
{% if @type.name != "Slice(T)" && T < Number %}
{{T}}.slice({{args.splat(", ")}}read_only: {{read_only}})
{% else %}
%ptr = Pointer(typeof({{*args}})).malloc({{args.size}})
{% for arg, i in args %}
%ptr[{{i}}] = {{arg}}
{% end %}
Slice.new(%ptr, {{args.size}}, read_only: {{read_only}})
{% end %}
end
# Returns the size of this slice.
#
# ```
# Slice(UInt8).new(3).size # => 3
# ```
getter size : Int32
# Returns `true` if this slice cannot be written to.
getter? read_only : Bool
# Creates a slice to the given *pointer*, bounded by the given *size*. This
# method does not allocate heap memory.
#
# ```
# ptr = Pointer.malloc(9) { |i| ('a'.ord + i).to_u8 }
#
# slice = Slice.new(ptr, 3)
# slice.size # => 3
# slice # => Bytes[97, 98, 99]
#
# String.new(slice) # => "abc"
# ```
def initialize(@pointer : Pointer(T), size : Int, *, @read_only = false)
@size = size.to_i32
end
# Allocates `size * sizeof(T)` bytes of heap memory initialized to zero
# and returns a slice pointing to that memory.
#
# The memory is allocated by the `GC`, so when there are
# no pointers to this memory, it will be automatically freed.
#
# Only works for primitive integers and floats (`UInt8`, `Int32`, `Float64`, etc.)
#
# ```
# slice = Slice(UInt8).new(3)
# slice # => Bytes[0, 0, 0]
# ```
def self.new(size : Int, *, read_only = false)
{% unless Number::Primitive.union_types.includes?(T) %}
{% raise "Can only use primitive integers and floats with Slice.new(size), not #{T}" %}
{% end %}
pointer = Pointer(T).malloc(size)
new(pointer, size, read_only: read_only)
end
# Allocates `size * sizeof(T)` bytes of heap memory initialized to the value
# returned by the block (which is invoked once with each index in the range `0...size`)
# and returns a slice pointing to that memory.
#
# The memory is allocated by the `GC`, so when there are
# no pointers to this memory, it will be automatically freed.
#
# ```
# slice = Slice.new(3) { |i| i + 10 }
# slice # => Slice[10, 11, 12]
# ```
def self.new(size : Int, *, read_only = false)
pointer = Pointer.malloc(size) { |i| yield i }
new(pointer, size, read_only: read_only)
end
# Allocates `size * sizeof(T)` bytes of heap memory initialized to *value*
# and returns a slice pointing to that memory.
#
# The memory is allocated by the `GC`, so when there are
# no pointers to this memory, it will be automatically freed.
#
# ```
# slice = Slice.new(3, 10)
# slice # => Slice[10, 10, 10]
# ```
def self.new(size : Int, value : T, *, read_only = false)
new(size, read_only: read_only) { value }
end
# Returns a deep copy of this slice.
#
# This method allocates memory for the slice copy and stores the return values
# from calling `#clone` on each item.
def clone
pointer = Pointer(T).malloc(size)
copy = self.class.new(pointer, size)
each_with_index do |item, i|
copy[i] = item.clone
end
copy
end
# Returns a shallow copy of this slice.
#
# This method allocates memory for the slice copy and duplicates the values.
def dup
pointer = Pointer(T).malloc(size)
copy = self.class.new(pointer, size)
copy.copy_from(self)
copy
end
# Creates an empty slice.
#
# ```
# slice = Slice(UInt8).empty
# slice.size # => 0
# ```
def self.empty : self
new(Pointer(T).null, 0)
end
# Returns a new slice that is *offset* elements apart from this slice.
#
# ```
# slice = Slice.new(5) { |i| i + 10 }
# slice # => Slice[10, 11, 12, 13, 14]
#
# slice2 = slice + 2
# slice2 # => Slice[12, 13, 14]
# ```
def +(offset : Int) : Slice(T)
check_size(offset)
Slice.new(@pointer + offset, @size - offset, read_only: @read_only)
end
# :inherit:
#
# Raises if this slice is read-only.
@[AlwaysInline]
def []=(index : Int, value : T) : T
check_writable
super
end
# Returns a new slice that starts at *start* elements from this slice's start,
# and of *count* size.
#
# Returns `nil` if the new slice falls outside this slice.
#
# ```
# slice = Slice.new(5) { |i| i + 10 }
# slice # => Slice[10, 11, 12, 13, 14]
#
# slice[1, 3]? # => Slice[11, 12, 13]
# slice[1, 33]? # => nil
# ```
def []?(start : Int, count : Int) : Slice(T)?
return unless 0 <= start <= @size
return unless 0 <= count <= @size - start
Slice.new(@pointer + start, count, read_only: @read_only)
end
# Returns a new slice that starts at *start* elements from this slice's start,
# and of *count* size.
#
# Raises `IndexError` if the new slice falls outside this slice.
#
# ```
# slice = Slice.new(5) { |i| i + 10 }
# slice # => Slice[10, 11, 12, 13, 14]
#
# slice[1, 3] # => Slice[11, 12, 13]
# slice[1, 33] # raises IndexError
# ```
def [](start : Int, count : Int) : Slice(T)
self[start, count]? || raise IndexError.new
end
# Returns a new slice with the elements in the given range.
#
# Negative indices count backward from the end of the slice (`-1` is the last
# element). Additionally, an empty slice is returned when the starting index
# for an element range is at the end of the slice.
#
# Returns `nil` if the new slice falls outside this slice.
#
# ```
# slice = Slice.new(5) { |i| i + 10 }
# slice # => Slice[10, 11, 12, 13, 14]
#
# slice[1..3]? # => Slice[11, 12, 13]
# slice[1..33]? # => nil
# ```
def []?(range : Range)
start, count = Indexable.range_to_index_and_count(range, size) || raise IndexError.new
self[start, count]?
end
# Returns a new slice with the elements in the given range.
#
# The first element in the returned slice is `self[range.begin]` followed
# by the next elements up to index `range.end` (or `self[range.end - 1]` if
# the range is exclusive).
# If there are fewer elements in `self`, the returned slice is shorter than
# `range.size`.
#
# ```
# a = Slice["a", "b", "c", "d", "e"]
# a[1..3] # => Slice["b", "c", "d"]
# ```
#
# Negative indices count backward from the end of the slice (`-1` is the last
# element). Additionally, an empty slice is returned when the starting index
# for an element range is at the end of the slice.
#
# Raises `IndexError` if the new slice falls outside this slice.
#
# ```
# slice = Slice.new(5) { |i| i + 10 }
# slice # => Slice[10, 11, 12, 13, 14]
#
# slice[1..3] # => Slice[11, 12, 13]
# slice[1..33] # raises IndexError
# ```
def [](range : Range) : Slice(T)
start, count = Indexable.range_to_index_and_count(range, size) || raise IndexError.new
self[start, count]
end
@[AlwaysInline]
def unsafe_fetch(index : Int) : T
@pointer[index]
end
@[AlwaysInline]
def unsafe_put(index : Int, value : T)
@pointer[index] = value
end
# :inherit:
#
# Raises if this slice is read-only.
def update(index : Int, & : T -> _) : T
check_writable
super { |elem| yield elem }
end
# :inherit:
#
# Raises if this slice is read-only.
def swap(index0 : Int, index1 : Int) : self
check_writable
super
end
# :inherit:
#
# Raises if this slice is read-only.
def reverse! : self
check_writable
super
end
# :inherit:
#
# Raises if this slice is read-only.
def shuffle!(random : Random = Random::DEFAULT) : self
check_writable
super
end
# :inherit:
#
# Raises if this slice is read-only.
def rotate!(n : Int = 1) : self
check_writable
return self if size == 0
n %= size
if n == 0
elsif n == 1
tmp = self[0]
@pointer.move_from(@pointer + n, size - n)
self[-1] = tmp
elsif n == (size - 1)
tmp = self[-1]
(@pointer + size - n).move_from(@pointer, n)
self[0] = tmp
elsif n <= SMALL_SLICE_SIZE
tmp_buffer = uninitialized T[SMALL_SLICE_SIZE]
tmp_buffer.to_unsafe.copy_from(@pointer, n)
@pointer.move_from(@pointer + n, size - n)
(@pointer + size - n).copy_from(tmp_buffer.to_unsafe, n)
elsif size - n <= SMALL_SLICE_SIZE
tmp_buffer = uninitialized T[SMALL_SLICE_SIZE]
tmp_buffer.to_unsafe.copy_from(@pointer + n, size - n)
(@pointer + size - n).move_from(@pointer, n)
@pointer.copy_from(tmp_buffer.to_unsafe, size - n)
elsif n <= size // 2
tmp = self[...n].dup
@pointer.move_from(@pointer + n, size - n)
(@pointer + size - n).copy_from(tmp.to_unsafe, n)
else
tmp = self[n..].dup
(@pointer + size - n).move_from(@pointer, n)
@pointer.copy_from(tmp.to_unsafe, size - n)
end
self
end
private SMALL_SLICE_SIZE = 16 # same as Array::SMALL_ARRAY_SIZE
# :inherit:
#
# Raises if this slice is read-only.
def map!(& : T -> _) : self
check_writable
super { |elem| yield elem }
end
# Returns a new slice where elements are mapped by the given block.
#
# ```
# slice = Slice[1, 2.5, "a"]
# slice.map &.to_s # => Slice["1", "2.5", "a"]
# ```
def map(*, read_only = false, & : T -> _)
Slice.new(size, read_only: read_only) { |i| yield @pointer[i] }
end
# :inherit:
#
# Raises if this slice is read-only.
def map_with_index!(offset = 0, & : T, Int32 -> _) : self
check_writable
super { |elem, i| yield elem, i }
end
# Like `map`, but the block gets passed both the element and its index.
#
# Accepts an optional *offset* parameter, which tells it to start counting
# from there.
def map_with_index(offset = 0, *, read_only = false, & : (T, Int32) -> _)
Slice.new(size, read_only: read_only) { |i| yield @pointer[i], offset + i }
end
# :inherit:
#
# Raises if this slice is read-only.
def fill(value : T) : self
check_writable
{% if T == UInt8 %}
Intrinsics.memset(to_unsafe.as(Void*), value, size, false)
self
{% else %}
{% if Number::Primitive.union_types.includes?(T) %}
if value == 0
to_unsafe.clear(size)
return self
end
{% end %}
fill { value }
{% end %}
end
# :inherit:
#
# Raises if this slice is read-only.
def fill(value : T, start : Int, count : Int) : self
# since `#[]` requires exactly *count* elements but we allow fewer here, we
# must normalize the indices beforehand
start, count = normalize_start_and_count(start, count)
self[start, count].fill(value)
self
end
# :inherit:
#
# Raises if this slice is read-only.
def fill(value : T, range : Range) : self
fill(value, *Indexable.range_to_index_and_count(range, size) || raise IndexError.new)
end
# :inherit:
#
# Raises if this slice is read-only.
def fill(*, offset : Int = 0, & : Int32 -> T) : self
check_writable
super { |i| yield i }
end
# :inherit:
#
# Raises if this slice is read-only.
def fill(start : Int, count : Int, & : Int32 -> T) : self
check_writable
super(start, count) { |i| yield i }
end
# :inherit:
#
# Raises if this slice is read-only.
def fill(range : Range, & : Int32 -> T) : self
check_writable
super(range) { |i| yield i }
end
def copy_from(source : Pointer(T), count)
check_writable
check_size(count)
@pointer.copy_from(source, count)
end
def copy_to(target : Pointer(T), count)
check_size(count)
@pointer.copy_to(target, count)
end
# Copies the contents of this slice into *target*.
#
# Raises `IndexError` if the destination slice cannot fit the data being transferred
# e.g. `dest.size < self.size`.
#
# ```
# src = Slice['a', 'a', 'a']
# dst = Slice['b', 'b', 'b', 'b', 'b']
# src.copy_to dst
# dst # => Slice['a', 'a', 'a', 'b', 'b']
# dst.copy_to src # raises IndexError
# ```
def copy_to(target : self)
target.check_writable
raise IndexError.new if target.size < size
@pointer.copy_to(target.to_unsafe, size)
end
# Copies the contents of *source* into this slice.
#
# Raises `IndexError` if the destination slice cannot fit the data being transferred.
@[AlwaysInline]
def copy_from(source : self)
source.copy_to(self)
end
def move_from(source : Pointer(T), count)
check_writable
check_size(count)
@pointer.move_from(source, count)
end
def move_to(target : Pointer(T), count)
@pointer.move_to(target, count)
end
# Moves the contents of this slice into *target*. *target* and `self` may
# overlap; the copy is always done in a non-destructive manner.
#
# Raises `IndexError` if the destination slice cannot fit the data being transferred
# e.g. `dest.size < self.size`.
#
# ```
# src = Slice['a', 'a', 'a']
# dst = Slice['b', 'b', 'b', 'b', 'b']
# src.move_to dst
# dst # => Slice['a', 'a', 'a', 'b', 'b']
# dst.move_to src # raises IndexError
# ```
#
# See also: `Pointer#move_to`.
def move_to(target : self)
target.check_writable
raise IndexError.new if target.size < size
@pointer.move_to(target.to_unsafe, size)
end
# Moves the contents of *source* into this slice. *source* and `self` may
# overlap; the copy is always done in a non-destructive manner.
#
# Raises `IndexError` if the destination slice cannot fit the data being transferred.
@[AlwaysInline]
def move_from(source : self)
source.move_to(self)
end
def inspect(io : IO) : Nil
to_s(io)
end
# Returns a new `Slice` pointing at the same contents as `self`, but
# reinterpreted as elements of the given *type*.
#
# The returned slice never refers to more memory than `self`; if the last
# bytes of `self` do not fit into a `U`, they are excluded from the returned
# slice.
#
# WARNING: This method is **unsafe**: elements are reinterpreted using
# `#unsafe_as`, and the resulting slice may not be properly aligned.
# Additionally, the same elements may produce different results depending on
# the system endianness.
#
# ```
# # assume little-endian system
# bytes = Bytes[0x01, 0x02, 0x03, 0x04, 0xFF, 0xFE]
# bytes.unsafe_slice_of(Int8) # => Slice[1_i8, 2_i8, 3_i8, 4_i8, -1_i8, -2_i8]
# bytes.unsafe_slice_of(Int16) # => Slice[513_i16, 1027_i16, -257_i16]
# bytes.unsafe_slice_of(Int32) # => Slice[0x04030201]
# ```
def unsafe_slice_of(type : U.class) : Slice(U) forall U
Slice.new(to_unsafe.unsafe_as(Pointer(U)), bytesize // sizeof(U), read_only: @read_only)
end
# Returns a new `Bytes` pointing at the same contents as `self`.
#
# WARNING: This method is **unsafe**: the returned slice is writable if `self`
# is also writable, and modifications through the returned slice may violate
# the binary representations of Crystal objects. Additionally, the same
# elements may produce different results depending on the system endianness.
#
# ```
# # assume little-endian system
# ints = Slice[0x01020304, 0x05060708]
# bytes = ints.to_unsafe_bytes # => Bytes[0x04, 0x03, 0x02, 0x01, 0x08, 0x07, 0x06, 0x05]
# bytes[2] = 0xAD
# ints # => Slice[0x01AD0304, 0x05060708]
# ```
def to_unsafe_bytes : Bytes
unsafe_slice_of(UInt8)
end
# Returns a hexstring representation of this slice.
#
# `self` must be a `Slice(UInt8)`. To call this method on other `Slice`s,
# `#to_unsafe_bytes` should be used first.
#
# ```
# UInt8.slice(97, 62, 63, 8, 255).hexstring # => "613e3f08ff"
#
# # assume little-endian system
# Int16.slice(97, 62, 1000, -2).to_unsafe_bytes.hexstring # => "61003e00e803feff"
# ```
def hexstring : String
{% unless T == UInt8 %}
{% raise "Can only call `#hexstring` on Slice(UInt8), not #{@type}" %}
{% end %}
str_size = size * 2
String.new(str_size) do |buffer|
hexstring(buffer)
{str_size, str_size}
end
end
# :nodoc:
def hexstring(buffer) : Nil
{% unless T == UInt8 %}
{% raise "Can only call `#hexstring` on Slice(UInt8), not #{@type}" %}
{% end %}
offset = 0
each do |v|
buffer[offset] = to_hex(v >> 4)
buffer[offset + 1] = to_hex(v & 0x0f)
offset += 2
end
nil
end
# Returns a hexdump of this slice.
#
# `self` must be a `Slice(UInt8)`. To call this method on other `Slice`s,
# `#to_unsafe_bytes` should be used first.
#
# This method is specially useful for debugging binary data and
# incoming/outgoing data in protocols.
#
# ```
# slice = UInt8.slice(97, 62, 63, 8, 255)
# slice.hexdump # => "00000000 61 3e 3f 08 ff a>?..\n"
#
# # assume little-endian system
# slice = Int16.slice(97, 62, 1000, -2)
# slice.to_unsafe_bytes.hexdump # => "00000000 61 00 3e 00 e8 03 fe ff a.>.....\n"
# ```
def hexdump : String
{% unless T == UInt8 %}
{% raise "Can only call `#hexdump` on Slice(UInt8), not #{@type}" %}
{% end %}
return "" if empty?
full_lines, leftover = size.divmod(16)
if leftover == 0
str_size = full_lines * 77
else
str_size = (full_lines + 1) * 77 - (16 - leftover)
end
String.new(str_size) do |buf|
pos = 0
offset = 0
while pos < size
# Ensure we don't write outside the buffer:
# slower, but safer (speed is not very important when hexdump is used)
hexdump_line(Slice.new(buf + offset, {77, str_size - offset}.min), pos)
pos += 16
offset += 77
end
{str_size, str_size}
end
end
# Writes a hexdump of this slice to the given *io*.
#
# `self` must be a `Slice(UInt8)`. To call this method on other `Slice`s,
# `#to_unsafe_bytes` should be used first.
#
# This method is specially useful for debugging binary data and
# incoming/outgoing data in protocols.
#
# Returns the number of bytes written to *io*.
#
# ```
# slice = UInt8.slice(97, 62, 63, 8, 255)
# slice.hexdump(STDOUT)
# ```
#
# Prints:
#
# ```text
# 00000000 61 3e 3f 08 ff a>?..
# ```
def hexdump(io : IO)
{% unless T == UInt8 %}
{% raise "Can only call `#hexdump` on Slice(UInt8), not #{@type}" %}
{% end %}
return 0 if empty?
line = uninitialized UInt8[77]
line_slice = line.to_slice
count = 0
pos = 0
while pos < size
line_bytes = hexdump_line(line_slice, pos)
io.write_string(line_slice[0, line_bytes])
count += line_bytes
pos += 16
end
io.flush
count
end
private def hexdump_line(line, start_pos)
hex_offset = 10
ascii_offset = 60
0.upto(7) do |j|
line[7 - j] = to_hex((start_pos >> (4 * j)) & 0xf)
end
line[8] = 0x20_u8
line[9] = 0x20_u8
pos = start_pos
16.times do |i|
break if pos >= size
v = unsafe_fetch(pos)
pos += 1
line[hex_offset] = to_hex(v >> 4)
line[hex_offset + 1] = to_hex(v & 0x0f)
line[hex_offset + 2] = 0x20_u8
hex_offset += 3
if i == 7
line[hex_offset] = 0x20_u8
hex_offset += 1
end
line[ascii_offset] = 0x20_u8 <= v <= 0x7e_u8 ? v : 0x2e_u8
ascii_offset += 1
end
while hex_offset < 60
line[hex_offset] = 0x20_u8
hex_offset += 1
end
if ascii_offset < line.size
line[ascii_offset] = 0x0a_u8
ascii_offset += 1
end
ascii_offset
end
private def to_hex(c)
((c < 10 ? 48_u8 : 87_u8) + c)
end
def bytesize : Int32
sizeof(T) * size
end
# Combined comparison operator.
#
# Returns a negative number, `0`, or a positive number depending on
# whether `self` is less than *other*, equals *other*.
#
# It compares the elements of both slices in the same position using the
# `<=>` operator. As soon as one of such comparisons returns a non-zero
# value, that result is the return value of the comparison.
#
# If all elements are equal, the comparison is based on the size of the arrays.
#
# ```
# Bytes[8] <=> Bytes[1, 2, 3] # => 7
# Bytes[2] <=> Bytes[4, 2, 3] # => -2
# Bytes[1, 2] <=> Bytes[1, 2] # => 0
# ```
def <=>(other : Slice(U)) forall U
min_size = Math.min(size, other.size)
{% if T == UInt8 && U == UInt8 %}
cmp = to_unsafe.memcmp(other.to_unsafe, min_size)
return cmp if cmp != 0
{% else %}
0.upto(min_size - 1) do |i|
n = to_unsafe[i] <=> other.to_unsafe[i]
return n if n != 0
end
{% end %}
size <=> other.size
end
# Returns `true` if `self` and *other* have the same size and all their
# elements are equal, `false` otherwise.
#
# ```
# Bytes[1, 2] == Bytes[1, 2] # => true
# Bytes[1, 3] == Bytes[1, 2] # => false
# Bytes[1, 2] == Bytes[1, 2, 3] # => false
# ```
def ==(other : Slice(U)) : Bool forall U
return false if size != other.size
{% if T == UInt8 && U == UInt8 %}
to_unsafe.memcmp(other.to_unsafe, size) == 0
{% else %}
each_with_index do |elem, i|
return false unless elem == other.to_unsafe[i]
end
true
{% end %}
end
def to_slice : self
self
end
def to_s(io : IO) : Nil
if T == UInt8
io << "Bytes["
# Inspect using to_s because we know this is a UInt8.
join io, ", ", &.to_s(io)
io << ']'
else
io << "Slice["
join io, ", ", &.inspect(io)
io << ']'
end
end
def pretty_print(pp) : Nil
prefix = T == UInt8 ? "Bytes[" : "Slice["
pp.list(prefix, self, "]")
end
def to_a
Array(T).build(@size) do |pointer|
pointer.copy_from(@pointer, @size)
@size
end
end
# Returns this slice's pointer.
#
# ```
# slice = Slice.new(3, 10)
# slice.to_unsafe[0] # => 10
# ```
def to_unsafe : Pointer(T)
@pointer
end
# Returns a new instance with all elements sorted based on the return value of
# their comparison method `T#<=>` (see `Comparable#<=>`), using a stable sort algorithm.
#
# ```
# a = Slice[3, 1, 2]
# a.sort # => Slice[1, 2, 3]
# a # => Slice[3, 1, 2]
# ```
#
# See `#sort!` for details on the sorting mechanism.
#
# Raises `ArgumentError` if the comparison between any two elements returns `nil`.
def sort : self
dup.sort!
end
# Returns a new instance with all elements sorted based on the return value of
# their comparison method `T#<=>` (see `Comparable#<=>`), using an unstable sort algorithm.
#
# ```
# a = Slice[3, 1, 2]
# a.unstable_sort # => Slice[1, 2, 3]
# a # => Slice[3, 1, 2]
# ```
#
# See `Indexable::Mutable#unstable_sort!` for details on the sorting mechanism.
#
# Raises `ArgumentError` if the comparison between any two elements returns `nil`.
def unstable_sort : self
dup.unstable_sort!
end
# Returns a new instance with all elements sorted based on the comparator in the
# given block, using a stable sort algorithm.
#
# ```
# a = Slice[3, 1, 2]
# b = a.sort { |a, b| b <=> a }
#
# b # => Slice[3, 2, 1]
# a # => Slice[3, 1, 2]
# ```
#
# See `Indexable::Mutable#sort!(&block : T, T -> U)` for details on the sorting mechanism.
#
# Raises `ArgumentError` if for any two elements the block returns `nil`.
def sort(&block : T, T -> U) : self forall U
{% unless U <= Int32? %}
{% raise "expected block to return Int32 or Nil, not #{U}" %}
{% end %}
dup.sort! &block
end
# Returns a new instance with all elements sorted based on the comparator in the
# given block, using an unstable sort algorithm.
#
# ```
# a = Slice[3, 1, 2]
# b = a.unstable_sort { |a, b| b <=> a }
#
# b # => Slice[3, 2, 1]
# a # => Slice[3, 1, 2]
# ```
#
# See `Indexable::Mutable#unstable_sort!(&block : T, T -> U)` for details on the sorting mechanism.
#
# Raises `ArgumentError` if for any two elements the block returns `nil`.
def unstable_sort(&block : T, T -> U) : self forall U
{% unless U <= Int32? %}
{% raise "expected block to return Int32 or Nil, not #{U}" %}
{% end %}
dup.unstable_sort!(&block)
end
# Sorts all elements in `self` based on the return value of the comparison
# method `T#<=>` (see `Comparable#<=>`), using a stable sort algorithm.
#
# ```
# slice = Slice[3, 1, 2]
# slice.sort!
# slice # => Slice[1, 2, 3]
# ```
#
# This sort operation modifies `self`. See `#sort` for a non-modifying option
# that allocates a new instance.
#
# The sort mechanism is implemented as [*merge sort*](https://en.wikipedia.org/wiki/Merge_sort).
# It is stable, which is typically a good default.
#
# Stability means that two elements which compare equal (i.e. `a <=> b == 0`)
# keep their original relation. Stable sort guarantees that `[a, b].sort!`
# always results in `[a, b]` (given they compare equal). With unstable sort,
# the result could also be `[b, a]`.
#
# If stability is expendable, `#unstable_sort!` provides a performance
# advantage over stable sort.
#
# Raises `ArgumentError` if the comparison between any two elements returns `nil`.
def sort! : self
Slice.merge_sort!(self)
self
end
# Sorts all elements in `self` based on the return value of the comparison
# method `T#<=>` (see `Comparable#<=>`), using an unstable sort algorithm..
#
# ```
# slice = Slice[3, 1, 2]
# slice.unstable_sort!
# slice # => Slice[1, 2, 3]
# ```
#
# This sort operation modifies `self`. See `#unstable_sort` for a non-modifying
# option that allocates a new instance.
#
# The sort mechanism is implemented as [*introsort*](https://en.wikipedia.org/wiki/Introsort).
# It does not guarantee stability between equally comparing elements.
# This offers higher performance but may be unexpected in some situations.
#
# Stability means that two elements which compare equal (i.e. `a <=> b == 0`)
# keep their original relation. Stable sort guarantees that `[a, b].sort!`
# always results in `[a, b]` (given they compare equal). With unstable sort,
# the result could also be `[b, a]`.
#
# If stability is necessary, use `#sort!` instead.
#
# Raises `ArgumentError` if the comparison between any two elements returns `nil`.
def unstable_sort! : self
Slice.intro_sort!(to_unsafe, size)
self
end
# Sorts all elements in `self` based on the comparator in the given block, using
# a stable sort algorithm.
#
# ```
# slice = Slice[3, 1, 2]
# # This is a reverse sort (forward sort would be `a <=> b`)
# slice.sort! { |a, b| b <=> a }
# slice # => Slice[3, 2, 1]
# ```
#
# The block must implement a comparison between two elements *a* and *b*,
# where `a < b` outputs a negative value, `a == b` outputs `0`, and `a > b`
# outputs a positive value.
# The comparison operator (`Comparable#<=>`) can be used for this.
#
# The block's output type must be `<= Int32?`, but returning an actual `nil`
# value is an error.
#
# This sort operation modifies `self`. See `#sort(&block : T, T -> U)` for a
# non-modifying option that allocates a new instance.
#