-
Notifications
You must be signed in to change notification settings - Fork 43
/
lib.rs
2869 lines (2580 loc) · 88.7 KB
/
lib.rs
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
//! `FixedBitSet` is a simple fixed size set of bits.
//!
//! ### Crate features
//!
//! - `std` (default feature)
//! Disabling this feature disables using std and instead uses crate alloc.
//!
//! ### SIMD Acceleration
//! `fixedbitset` is written with SIMD in mind. The backing store and set operations will use aligned SIMD data types and instructions when compiling
//! for compatible target platforms. The use of SIMD generally enables better performance in many set and batch operations (i.e. intersection/union/inserting a range).
//!
//! When SIMD is not available on the target, the crate will gracefully fallback to a default implementation. It is intended to add support for other SIMD architectures
//! once they appear in stable Rust.
//!
//! Currently only SSE2/AVX/AVX2 on x86/x86_64 and wasm32 SIMD are supported as this is what stable Rust supports.
#![no_std]
#![deny(clippy::undocumented_unsafe_blocks)]
extern crate alloc;
use alloc::{vec, vec::Vec};
mod block;
mod range;
#[cfg(feature = "serde")]
extern crate serde;
#[cfg(feature = "serde")]
mod serde_impl;
use core::fmt::Write;
use core::fmt::{Binary, Display, Error, Formatter};
use core::cmp::Ordering;
use core::hash::Hash;
use core::iter::{Chain, FusedIterator};
use core::mem::ManuallyDrop;
use core::ops::{BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign, Index};
use core::ptr::NonNull;
pub use range::IndexRange;
pub(crate) const BITS: usize = core::mem::size_of::<Block>() * 8;
#[cfg(feature = "serde")]
pub(crate) const BYTES: usize = core::mem::size_of::<Block>();
use block::Block as SimdBlock;
pub type Block = usize;
#[inline]
fn div_rem(x: usize, denominator: usize) -> (usize, usize) {
(x / denominator, x % denominator)
}
fn vec_into_parts<T>(vec: Vec<T>) -> (NonNull<T>, usize, usize) {
let mut vec = ManuallyDrop::new(vec);
(
// SAFETY: A Vec's internal pointer is always non-null.
unsafe { NonNull::new_unchecked(vec.as_mut_ptr()) },
vec.capacity(),
vec.len(),
)
}
/// `FixedBitSet` is a simple fixed size set of bits that each can
/// be enabled (1 / **true**) or disabled (0 / **false**).
///
/// The bit set has a fixed capacity in terms of enabling bits (and the
/// capacity can grow using the `grow` method).
///
/// Derived traits depend on both the zeros and ones, so [0,1] is not equal to
/// [0,1,0].
#[derive(Debug, Eq)]
pub struct FixedBitSet {
pub(crate) data: NonNull<SimdBlock>,
capacity: usize,
/// length in bits
pub(crate) length: usize,
}
impl FixedBitSet {
/// Create a new empty **FixedBitSet**.
pub const fn new() -> Self {
FixedBitSet {
data: NonNull::dangling(),
capacity: 0,
length: 0,
}
}
/// Create a new **FixedBitSet** with a specific number of bits,
/// all initially clear.
pub fn with_capacity(bits: usize) -> Self {
let (mut blocks, rem) = div_rem(bits, SimdBlock::BITS);
blocks += (rem > 0) as usize;
Self::from_blocks_and_len(vec![SimdBlock::NONE; blocks], bits)
}
#[inline]
fn from_blocks_and_len(data: Vec<SimdBlock>, length: usize) -> Self {
let (data, capacity, _) = vec_into_parts(data);
FixedBitSet {
data,
capacity,
length,
}
}
/// Create a new **FixedBitSet** with a specific number of bits,
/// initialized from provided blocks.
///
/// If the blocks are not the exact size needed for the capacity
/// they will be padded with zeros (if shorter) or truncated to
/// the capacity (if longer).
///
/// For example:
/// ```
/// let data = vec![4];
/// let bs = fixedbitset::FixedBitSet::with_capacity_and_blocks(4, data);
/// assert_eq!(format!("{:b}", bs), "0010");
/// ```
pub fn with_capacity_and_blocks<I: IntoIterator<Item = Block>>(bits: usize, blocks: I) -> Self {
let mut bitset = Self::with_capacity(bits);
for (subblock, value) in bitset.as_mut_slice().iter_mut().zip(blocks.into_iter()) {
*subblock = value;
}
bitset
}
/// Grow capacity to **bits**, all new bits initialized to zero
#[inline]
pub fn grow(&mut self, bits: usize) {
if bits <= self.length {
return;
}
// SAFETY: The data pointer and capacity were created from a Vec initially. The block
// len is identical to that of the original.
let mut data = unsafe {
Vec::from_raw_parts(self.data.as_ptr(), self.simd_block_len(), self.capacity)
};
let (mut blocks, rem) = div_rem(bits, SimdBlock::BITS);
blocks += (rem > 0) as usize;
data.resize(blocks, SimdBlock::NONE);
let (data, capacity, _) = vec_into_parts(data);
self.data = data;
self.capacity = capacity;
self.length = bits;
}
#[inline]
unsafe fn get_unchecked(&self, subblock: usize) -> &Block {
&*self.data.as_ptr().cast::<Block>().add(subblock)
}
#[inline]
unsafe fn get_unchecked_mut(&mut self, subblock: usize) -> &mut Block {
&mut *self.data.as_ptr().cast::<Block>().add(subblock)
}
#[inline]
fn usize_len(&self) -> usize {
let (mut blocks, rem) = div_rem(self.length, BITS);
blocks += (rem > 0) as usize;
blocks
}
#[inline]
fn simd_block_len(&self) -> usize {
let (mut blocks, rem) = div_rem(self.length, SimdBlock::BITS);
blocks += (rem > 0) as usize;
blocks
}
#[inline]
fn batch_count_ones(blocks: impl IntoIterator<Item = Block>) -> usize {
blocks.into_iter().map(|x| x.count_ones() as usize).sum()
}
#[inline]
fn as_simd_slice(&self) -> &[SimdBlock] {
// SAFETY: The slice constructed is within bounds of the underlying allocation. This function
// is called with a read-only borrow so no other write can happen as long as the returned borrow lives.
unsafe { core::slice::from_raw_parts(self.data.as_ptr(), self.simd_block_len()) }
}
#[inline]
fn as_mut_simd_slice(&mut self) -> &mut [SimdBlock] {
// SAFETY: The slice constructed is within bounds of the underlying allocation. This function
// is called with a mutable borrow so no other read or write can happen as long as the returned borrow lives.
unsafe { core::slice::from_raw_parts_mut(self.data.as_ptr(), self.simd_block_len()) }
}
/// Grows the internal size of the bitset before inserting a bit
///
/// Unlike `insert`, this cannot panic, but may allocate if the bit is outside of the existing buffer's range.
///
/// This is faster than calling `grow` then `insert` in succession.
#[inline]
pub fn grow_and_insert(&mut self, bits: usize) {
self.grow(bits + 1);
let (blocks, rem) = div_rem(bits, BITS);
// SAFETY: The above grow ensures that the block is inside the Vec's allocation.
unsafe {
*self.get_unchecked_mut(blocks) |= 1 << rem;
}
}
/// The length of the [`FixedBitSet`] in bits.
///
/// Note: `len` includes both set and unset bits.
/// ```
/// # use fixedbitset::FixedBitSet;
/// let bitset = FixedBitSet::with_capacity(10);
/// // there are 0 set bits, but 10 unset bits
/// assert_eq!(bitset.len(), 10);
/// ```
/// `len` does not return the count of set bits. For that, use
/// [`bitset.count_ones(..)`](FixedBitSet::count_ones) instead.
#[inline]
pub fn len(&self) -> usize {
self.length
}
/// `true` if the [`FixedBitSet`] is empty.
///
/// Note that an "empty" `FixedBitSet` is a `FixedBitSet` with
/// no bits (meaning: it's length is zero). If you want to check
/// if all bits are unset, use [`FixedBitSet::is_clear`].
///
/// ```
/// # use fixedbitset::FixedBitSet;
/// let bitset = FixedBitSet::with_capacity(10);
/// assert!(!bitset.is_empty());
///
/// let bitset = FixedBitSet::with_capacity(0);
/// assert!(bitset.is_empty());
/// ```
#[inline]
pub fn is_empty(&self) -> bool {
self.len() == 0
}
/// `true` if all bits in the [`FixedBitSet`] are unset.
///
/// As opposed to [`FixedBitSet::is_empty`], which is `true` only for
/// sets without any bits, set or unset.
///
/// ```
/// # use fixedbitset::FixedBitSet;
/// let mut bitset = FixedBitSet::with_capacity(10);
/// assert!(bitset.is_clear());
///
/// bitset.insert(2);
/// assert!(!bitset.is_clear());
/// ```
///
/// This is equivalent to [`bitset.count_ones(..) == 0`](FixedBitSet::count_ones).
#[inline]
pub fn is_clear(&self) -> bool {
self.as_simd_slice().iter().all(|block| block.is_empty())
}
/// Finds the lowest set bit in the bitset.
///
/// Returns `None` if there aren't any set bits.
///
/// ```
/// # use fixedbitset::FixedBitSet;
/// let mut bitset = FixedBitSet::with_capacity(10);
/// assert_eq!(bitset.minimum(), None);
///
/// bitset.insert(2);
/// assert_eq!(bitset.minimum(), Some(2));
/// bitset.insert(8);
/// assert_eq!(bitset.minimum(), Some(2));
/// ```
#[inline]
pub fn minimum(&self) -> Option<usize> {
let (block_idx, block) = self
.as_simd_slice()
.iter()
.enumerate()
.find(|&(_, block)| !block.is_empty())?;
let mut inner = 0;
let mut trailing = 0;
for subblock in block.into_usize_array() {
if subblock != 0 {
trailing = subblock.trailing_zeros() as usize;
break;
} else {
inner += BITS;
}
}
Some(block_idx * SimdBlock::BITS + inner + trailing)
}
/// Finds the highest set bit in the bitset.
///
/// Returns `None` if there aren't any set bits.
///
/// ```
/// # use fixedbitset::FixedBitSet;
/// let mut bitset = FixedBitSet::with_capacity(10);
/// assert_eq!(bitset.maximum(), None);
///
/// bitset.insert(8);
/// assert_eq!(bitset.maximum(), Some(8));
/// bitset.insert(2);
/// assert_eq!(bitset.maximum(), Some(8));
/// ```
#[inline]
pub fn maximum(&self) -> Option<usize> {
let (block_idx, block) = self
.as_simd_slice()
.iter()
.rev()
.enumerate()
.find(|&(_, block)| !block.is_empty())?;
let mut inner = 0;
let mut leading = 0;
for subblock in block.into_usize_array().iter().rev() {
if *subblock != 0 {
leading = subblock.leading_zeros() as usize;
break;
} else {
inner += BITS;
}
}
let max = self.simd_block_len() * SimdBlock::BITS;
Some(max - block_idx * SimdBlock::BITS - inner - leading - 1)
}
/// `true` if all bits in the [`FixedBitSet`] are set.
///
/// ```
/// # use fixedbitset::FixedBitSet;
/// let mut bitset = FixedBitSet::with_capacity(10);
/// assert!(!bitset.is_full());
///
/// bitset.insert_range(..);
/// assert!(bitset.is_full());
/// ```
///
/// This is equivalent to [`bitset.count_ones(..) == bitset.len()`](FixedBitSet::count_ones).
#[inline]
pub fn is_full(&self) -> bool {
self.contains_all_in_range(..)
}
/// Return **true** if the bit is enabled in the **FixedBitSet**,
/// **false** otherwise.
///
/// Note: bits outside the capacity are always disabled.
///
/// Note: Also available with index syntax: `bitset[bit]`.
#[inline]
pub fn contains(&self, bit: usize) -> bool {
(bit < self.length)
// SAFETY: The above check ensures that the block and bit are within bounds.
.then(|| unsafe { self.contains_unchecked(bit) })
.unwrap_or(false)
}
/// Return **true** if the bit is enabled in the **FixedBitSet**,
/// **false** otherwise.
///
/// Note: unlike `contains`, calling this with an invalid `bit`
/// is undefined behavior.
///
/// # Safety
/// `bit` must be less than `self.len()`
#[inline]
pub unsafe fn contains_unchecked(&self, bit: usize) -> bool {
let (block, i) = div_rem(bit, BITS);
(self.get_unchecked(block) & (1 << i)) != 0
}
/// Clear all bits.
#[inline]
pub fn clear(&mut self) {
for elt in self.as_mut_simd_slice().iter_mut() {
*elt = SimdBlock::NONE
}
}
/// Enable `bit`.
///
/// **Panics** if **bit** is out of bounds.
#[inline]
pub fn insert(&mut self, bit: usize) {
assert!(
bit < self.length,
"insert at index {} exceeds fixedbitset size {}",
bit,
self.length
);
// SAFETY: The above assertion ensures that the block is inside the Vec's allocation.
unsafe {
self.insert_unchecked(bit);
}
}
/// Enable `bit` without any length checks.
///
/// # Safety
/// `bit` must be less than `self.len()`
#[inline]
pub unsafe fn insert_unchecked(&mut self, bit: usize) {
let (block, i) = div_rem(bit, BITS);
// SAFETY: The above assertion ensures that the block is inside the Vec's allocation.
unsafe {
*self.get_unchecked_mut(block) |= 1 << i;
}
}
/// Disable `bit`.
///
/// **Panics** if **bit** is out of bounds.
#[inline]
pub fn remove(&mut self, bit: usize) {
assert!(
bit < self.length,
"remove at index {} exceeds fixedbitset size {}",
bit,
self.length
);
// SAFETY: The above assertion ensures that the block is inside the Vec's allocation.
unsafe {
self.remove_unchecked(bit);
}
}
/// Disable `bit` without any bounds checking.
///
/// # Safety
/// `bit` must be less than `self.len()`
#[inline]
pub unsafe fn remove_unchecked(&mut self, bit: usize) {
let (block, i) = div_rem(bit, BITS);
// SAFETY: The above assertion ensures that the block is inside the Vec's allocation.
unsafe {
*self.get_unchecked_mut(block) &= !(1 << i);
}
}
/// Enable `bit`, and return its previous value.
///
/// **Panics** if **bit** is out of bounds.
#[inline]
pub fn put(&mut self, bit: usize) -> bool {
assert!(
bit < self.length,
"put at index {} exceeds fixedbitset size {}",
bit,
self.length
);
// SAFETY: The above assertion ensures that the block is inside the Vec's allocation.
unsafe { self.put_unchecked(bit) }
}
/// Enable `bit`, and return its previous value without doing any bounds checking.
///
/// # Safety
/// `bit` must be less than `self.len()`
#[inline]
pub unsafe fn put_unchecked(&mut self, bit: usize) -> bool {
let (block, i) = div_rem(bit, BITS);
// SAFETY: The above assertion ensures that the block is inside the Vec's allocation.
unsafe {
let word = self.get_unchecked_mut(block);
let prev = *word & (1 << i) != 0;
*word |= 1 << i;
prev
}
}
/// Toggle `bit` (inverting its state).
///
/// ***Panics*** if **bit** is out of bounds
#[inline]
pub fn toggle(&mut self, bit: usize) {
assert!(
bit < self.length,
"toggle at index {} exceeds fixedbitset size {}",
bit,
self.length
);
// SAFETY: The above assertion ensures that the block is inside the Vec's allocation.
unsafe {
self.toggle_unchecked(bit);
}
}
/// Toggle `bit` (inverting its state) without any bounds checking.
///
/// # Safety
/// `bit` must be less than `self.len()`
#[inline]
pub unsafe fn toggle_unchecked(&mut self, bit: usize) {
let (block, i) = div_rem(bit, BITS);
// SAFETY: The above assertion ensures that the block is inside the Vec's allocation.
unsafe {
*self.get_unchecked_mut(block) ^= 1 << i;
}
}
/// Sets a bit to the provided `enabled` value.
///
/// **Panics** if **bit** is out of bounds.
#[inline]
pub fn set(&mut self, bit: usize, enabled: bool) {
assert!(
bit < self.length,
"set at index {} exceeds fixedbitset size {}",
bit,
self.length
);
// SAFETY: The above assertion ensures that the block is inside the Vec's allocation.
unsafe {
self.set_unchecked(bit, enabled);
}
}
/// Sets a bit to the provided `enabled` value without doing any bounds checking.
///
/// # Safety
/// `bit` must be less than `self.len()`
#[inline]
pub unsafe fn set_unchecked(&mut self, bit: usize, enabled: bool) {
let (block, i) = div_rem(bit, BITS);
// SAFETY: The above assertion ensures that the block is inside the Vec's allocation.
let elt = unsafe { self.get_unchecked_mut(block) };
if enabled {
*elt |= 1 << i;
} else {
*elt &= !(1 << i);
}
}
/// Copies boolean value from specified bit to the specified bit.
///
/// If `from` is out-of-bounds, `to` will be unset.
///
/// **Panics** if **to** is out of bounds.
#[inline]
pub fn copy_bit(&mut self, from: usize, to: usize) {
assert!(
to < self.length,
"copy to index {} exceeds fixedbitset size {}",
to,
self.length
);
let enabled = self.contains(from);
// SAFETY: The above assertion ensures that the block is inside the Vec's allocation.
unsafe { self.set_unchecked(to, enabled) };
}
/// Copies boolean value from specified bit to the specified bit.
///
/// Note: unlike `copy_bit`, calling this with an invalid `from`
/// is undefined behavior.
///
/// # Safety
/// `to` must both be less than `self.len()`
#[inline]
pub unsafe fn copy_bit_unchecked(&mut self, from: usize, to: usize) {
// SAFETY: Caller must ensure that `from` is within bounds.
let enabled = self.contains_unchecked(from);
// SAFETY: Caller must ensure that `to` is within bounds.
self.set_unchecked(to, enabled);
}
/// Count the number of set bits in the given bit range.
///
/// This function is potentially much faster than using `ones(other).count()`.
/// Use `..` to count the whole content of the bitset.
///
/// **Panics** if the range extends past the end of the bitset.
#[inline]
pub fn count_ones<T: IndexRange>(&self, range: T) -> usize {
Self::batch_count_ones(Masks::new(range, self.length).map(|(block, mask)| {
// SAFETY: Masks cannot return a block index that is out of range.
unsafe { *self.get_unchecked(block) & mask }
}))
}
/// Count the number of unset bits in the given bit range.
///
/// This function is potentially much faster than using `zeroes(other).count()`.
/// Use `..` to count the whole content of the bitset.
///
/// **Panics** if the range extends past the end of the bitset.
#[inline]
pub fn count_zeroes<T: IndexRange>(&self, range: T) -> usize {
Self::batch_count_ones(Masks::new(range, self.length).map(|(block, mask)| {
// SAFETY: Masks cannot return a block index that is out of range.
unsafe { !*self.get_unchecked(block) & mask }
}))
}
/// Sets every bit in the given range to the given state (`enabled`)
///
/// Use `..` to set the whole bitset.
///
/// **Panics** if the range extends past the end of the bitset.
#[inline]
pub fn set_range<T: IndexRange>(&mut self, range: T, enabled: bool) {
if enabled {
self.insert_range(range);
} else {
self.remove_range(range);
}
}
/// Enables every bit in the given range.
///
/// Use `..` to make the whole bitset ones.
///
/// **Panics** if the range extends past the end of the bitset.
#[inline]
pub fn insert_range<T: IndexRange>(&mut self, range: T) {
for (block, mask) in Masks::new(range, self.length) {
// SAFETY: Masks cannot return a block index that is out of range.
let block = unsafe { self.get_unchecked_mut(block) };
*block |= mask;
}
}
/// Disables every bit in the given range.
///
/// Use `..` to make the whole bitset ones.
///
/// **Panics** if the range extends past the end of the bitset.
#[inline]
pub fn remove_range<T: IndexRange>(&mut self, range: T) {
for (block, mask) in Masks::new(range, self.length) {
// SAFETY: Masks cannot return a block index that is out of range.
let block = unsafe { self.get_unchecked_mut(block) };
*block &= !mask;
}
}
/// Toggles (inverts) every bit in the given range.
///
/// Use `..` to toggle the whole bitset.
///
/// **Panics** if the range extends past the end of the bitset.
#[inline]
pub fn toggle_range<T: IndexRange>(&mut self, range: T) {
for (block, mask) in Masks::new(range, self.length) {
// SAFETY: Masks cannot return a block index that is out of range.
let block = unsafe { self.get_unchecked_mut(block) };
*block ^= mask;
}
}
/// Checks if the bitset contains every bit in the given range.
///
/// **Panics** if the range extends past the end of the bitset.
#[inline]
pub fn contains_all_in_range<T: IndexRange>(&self, range: T) -> bool {
for (block, mask) in Masks::new(range, self.length) {
// SAFETY: Masks cannot return a block index that is out of range.
let block = unsafe { self.get_unchecked(block) };
if block & mask != mask {
return false;
}
}
true
}
/// Checks if the bitset contains at least one set bit in the given range.
///
/// **Panics** if the range extends past the end of the bitset.
#[inline]
pub fn contains_any_in_range<T: IndexRange>(&self, range: T) -> bool {
for (block, mask) in Masks::new(range, self.length) {
// SAFETY: Masks cannot return a block index that is out of range.
let block = unsafe { self.get_unchecked(block) };
if block & mask != 0 {
return true;
}
}
false
}
/// View the bitset as a slice of `Block` blocks
#[inline]
pub fn as_slice(&self) -> &[Block] {
// SAFETY: The bits from both usize and Block are required to be reinterprettable, and
// neither have any padding or alignment issues. The slice constructed is within bounds
// of the underlying allocation. This function is called with a read-only borrow so
// no other write can happen as long as the returned borrow lives.
unsafe {
let ptr = self.data.as_ptr().cast::<Block>();
core::slice::from_raw_parts(ptr, self.usize_len())
}
}
/// View the bitset as a mutable slice of `Block` blocks. Writing past the bitlength in the last
/// will cause `contains` to return potentially incorrect results for bits past the bitlength.
#[inline]
pub fn as_mut_slice(&mut self) -> &mut [Block] {
// SAFETY: The bits from both usize and Block are required to be reinterprettable, and
// neither have any padding or alignment issues. The slice constructed is within bounds
// of the underlying allocation. This function is called with a mutable borrow so
// no other read or write can happen as long as the returned borrow lives.
unsafe {
let ptr = self.data.as_ptr().cast::<Block>();
core::slice::from_raw_parts_mut(ptr, self.usize_len())
}
}
/// Iterates over all enabled bits.
///
/// Iterator element is the index of the `1` bit, type `usize`.
#[inline]
pub fn ones(&self) -> Ones {
match self.as_slice().split_first() {
Some((&first_block, rem)) => {
let (&last_block, rem) = rem.split_last().unwrap_or((&0, rem));
Ones {
bitset_front: first_block,
bitset_back: last_block,
block_idx_front: 0,
block_idx_back: (1 + rem.len()) * BITS,
remaining_blocks: rem.iter(),
}
}
None => Ones {
bitset_front: 0,
bitset_back: 0,
block_idx_front: 0,
block_idx_back: 0,
remaining_blocks: [].iter(),
},
}
}
/// Iterates over all enabled bits.
///
/// Iterator element is the index of the `1` bit, type `usize`.
/// Unlike `ones`, this function consumes the `FixedBitset`.
pub fn into_ones(self) -> IntoOnes {
let ptr = self.data.as_ptr().cast();
let len = self.simd_block_len() * SimdBlock::USIZE_COUNT;
// SAFETY:
// - ptr comes from self.data, so it is valid;
// - self.data is valid for self.data.len() SimdBlocks,
// which is exactly self.data.len() * SimdBlock::USIZE_COUNT usizes;
// - we will keep this slice around only as long as self.data is,
// so it won't become dangling.
let slice = unsafe { core::slice::from_raw_parts(ptr, len) };
// SAFETY: The data pointer and capacity were created from a Vec initially. The block
// len is identical to that of the original.
let data = unsafe {
Vec::from_raw_parts(self.data.as_ptr(), self.simd_block_len(), self.capacity)
};
let mut iter = slice.iter().copied();
core::mem::forget(self);
IntoOnes {
bitset_front: iter.next().unwrap_or(0),
bitset_back: iter.next_back().unwrap_or(0),
block_idx_front: 0,
block_idx_back: len.saturating_sub(1) * BITS,
remaining_blocks: iter,
_buf: data,
}
}
/// Iterates over all disabled bits.
///
/// Iterator element is the index of the `0` bit, type `usize`.
#[inline]
pub fn zeroes(&self) -> Zeroes {
match self.as_slice().split_first() {
Some((&block, rem)) => Zeroes {
bitset: !block,
block_idx: 0,
len: self.len(),
remaining_blocks: rem.iter(),
},
None => Zeroes {
bitset: !0,
block_idx: 0,
len: self.len(),
remaining_blocks: [].iter(),
},
}
}
/// Returns a lazy iterator over the intersection of two `FixedBitSet`s
pub fn intersection<'a>(&'a self, other: &'a FixedBitSet) -> Intersection<'a> {
Intersection {
iter: self.ones(),
other,
}
}
/// Returns a lazy iterator over the union of two `FixedBitSet`s.
pub fn union<'a>(&'a self, other: &'a FixedBitSet) -> Union<'a> {
Union {
iter: self.ones().chain(other.difference(self)),
}
}
/// Returns a lazy iterator over the difference of two `FixedBitSet`s. The difference of `a`
/// and `b` is the elements of `a` which are not in `b`.
pub fn difference<'a>(&'a self, other: &'a FixedBitSet) -> Difference<'a> {
Difference {
iter: self.ones(),
other,
}
}
/// Returns a lazy iterator over the symmetric difference of two `FixedBitSet`s.
/// The symmetric difference of `a` and `b` is the elements of one, but not both, sets.
pub fn symmetric_difference<'a>(&'a self, other: &'a FixedBitSet) -> SymmetricDifference<'a> {
SymmetricDifference {
iter: self.difference(other).chain(other.difference(self)),
}
}
/// In-place union of two `FixedBitSet`s.
///
/// On calling this method, `self`'s capacity may be increased to match `other`'s.
pub fn union_with(&mut self, other: &FixedBitSet) {
if other.len() >= self.len() {
self.grow(other.len());
}
self.as_mut_simd_slice()
.iter_mut()
.zip(other.as_simd_slice().iter())
.for_each(|(x, y)| *x |= *y);
}
/// In-place intersection of two `FixedBitSet`s.
///
/// On calling this method, `self`'s capacity will remain the same as before.
pub fn intersect_with(&mut self, other: &FixedBitSet) {
let me = self.as_mut_simd_slice();
let other = other.as_simd_slice();
me.iter_mut().zip(other.iter()).for_each(|(x, y)| {
*x &= *y;
});
let mn = core::cmp::min(me.len(), other.len());
for wd in &mut me[mn..] {
*wd = SimdBlock::NONE;
}
}
/// In-place difference of two `FixedBitSet`s.
///
/// On calling this method, `self`'s capacity will remain the same as before.
pub fn difference_with(&mut self, other: &FixedBitSet) {
self.as_mut_simd_slice()
.iter_mut()
.zip(other.as_simd_slice().iter())
.for_each(|(x, y)| {
*x &= !*y;
});
// There's no need to grow self or do any other adjustments.
//
// * If self is longer than other, the bits at the end of self won't be affected since other
// has them implicitly set to 0.
// * If other is longer than self, the bits at the end of other are irrelevant since self
// has them set to 0 anyway.
}
/// In-place symmetric difference of two `FixedBitSet`s.
///
/// On calling this method, `self`'s capacity may be increased to match `other`'s.
pub fn symmetric_difference_with(&mut self, other: &FixedBitSet) {
if other.len() >= self.len() {
self.grow(other.len());
}
self.as_mut_simd_slice()
.iter_mut()
.zip(other.as_simd_slice().iter())
.for_each(|(x, y)| {
*x ^= *y;
});
}
/// Computes how many bits would be set in the union between two bitsets.
///
/// This is potentially much faster than using `union(other).count()`. Unlike
/// other methods like using [`union_with`] followed by [`count_ones`], this
/// does not mutate in place or require separate allocations.
#[inline]
pub fn union_count(&self, other: &FixedBitSet) -> usize {
let me = self.as_slice();
let other = other.as_slice();
let count = Self::batch_count_ones(me.iter().zip(other.iter()).map(|(x, y)| (*x | *y)));
match other.len().cmp(&me.len()) {
Ordering::Greater => count + Self::batch_count_ones(other[me.len()..].iter().copied()),
Ordering::Less => count + Self::batch_count_ones(me[other.len()..].iter().copied()),
Ordering::Equal => count,
}
}
/// Computes how many bits would be set in the intersection between two bitsets.
///
/// This is potentially much faster than using `intersection(other).count()`. Unlike
/// other methods like using [`intersect_with`] followed by [`count_ones`], this
/// does not mutate in place or require separate allocations.
#[inline]
pub fn intersection_count(&self, other: &FixedBitSet) -> usize {
Self::batch_count_ones(
self.as_slice()
.iter()
.zip(other.as_slice())
.map(|(x, y)| (*x & *y)),
)
}
/// Computes how many bits would be set in the difference between two bitsets.
///
/// This is potentially much faster than using `difference(other).count()`. Unlike
/// other methods like using [`difference_with`] followed by [`count_ones`], this
/// does not mutate in place or require separate allocations.
#[inline]
pub fn difference_count(&self, other: &FixedBitSet) -> usize {
Self::batch_count_ones(
self.as_slice()
.iter()
.zip(other.as_slice().iter())
.map(|(x, y)| (*x & !*y)),
)
}
/// Computes how many bits would be set in the symmetric difference between two bitsets.
///
/// This is potentially much faster than using `symmetric_difference(other).count()`. Unlike
/// other methods like using [`symmetric_difference_with`] followed by [`count_ones`], this
/// does not mutate in place or require separate allocations.
#[inline]
pub fn symmetric_difference_count(&self, other: &FixedBitSet) -> usize {
let me = self.as_slice();
let other = other.as_slice();
let count = Self::batch_count_ones(me.iter().zip(other.iter()).map(|(x, y)| (*x ^ *y)));
match other.len().cmp(&me.len()) {
Ordering::Greater => count + Self::batch_count_ones(other[me.len()..].iter().copied()),
Ordering::Less => count + Self::batch_count_ones(me[other.len()..].iter().copied()),
Ordering::Equal => count,
}
}
/// Returns `true` if `self` has no elements in common with `other`. This
/// is equivalent to checking for an empty intersection.
pub fn is_disjoint(&self, other: &FixedBitSet) -> bool {
self.as_simd_slice()
.iter()
.zip(other.as_simd_slice())
.all(|(x, y)| (*x & *y).is_empty())
}
/// Returns `true` if the set is a subset of another, i.e. `other` contains
/// at least all the values in `self`.
pub fn is_subset(&self, other: &FixedBitSet) -> bool {
let me = self.as_simd_slice();
let other = other.as_simd_slice();
me.iter()
.zip(other.iter())
.all(|(x, y)| x.andnot(*y).is_empty())
&& me.iter().skip(other.len()).all(|x| x.is_empty())
}
/// Returns `true` if the set is a superset of another, i.e. `self` contains
/// at least all the values in `other`.
pub fn is_superset(&self, other: &FixedBitSet) -> bool {
other.is_subset(self)
}
}
impl Hash for FixedBitSet {
fn hash<H: core::hash::Hasher>(&self, state: &mut H) {
self.length.hash(state);
self.as_simd_slice().hash(state);
}
}
impl PartialEq for FixedBitSet {
fn eq(&self, other: &Self) -> bool {
self.as_simd_slice().eq(other.as_simd_slice()) && self.length == other.length
}
}
impl PartialOrd for FixedBitSet {
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl Ord for FixedBitSet {
fn cmp(&self, other: &Self) -> Ordering {
self.length
.cmp(&other.length)