master
1//===- sanitizer_dense_map.h - Dense probed hash table ----------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This is fork of llvm/ADT/DenseMap.h class with the following changes:
10// * Use mmap to allocate.
11// * No iterators.
12// * Does not shrink.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef SANITIZER_DENSE_MAP_H
17#define SANITIZER_DENSE_MAP_H
18
19#include "sanitizer_common.h"
20#include "sanitizer_dense_map_info.h"
21#include "sanitizer_internal_defs.h"
22#include "sanitizer_type_traits.h"
23
24namespace __sanitizer {
25
26template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT,
27 typename BucketT>
28class DenseMapBase {
29 public:
30 using size_type = unsigned;
31 using key_type = KeyT;
32 using mapped_type = ValueT;
33 using value_type = BucketT;
34
35 WARN_UNUSED_RESULT bool empty() const { return getNumEntries() == 0; }
36 unsigned size() const { return getNumEntries(); }
37
38 /// Grow the densemap so that it can contain at least \p NumEntries items
39 /// before resizing again.
40 void reserve(size_type NumEntries) {
41 auto NumBuckets = getMinBucketToReserveForEntries(NumEntries);
42 if (NumBuckets > getNumBuckets())
43 grow(NumBuckets);
44 }
45
46 void clear() {
47 if (getNumEntries() == 0 && getNumTombstones() == 0)
48 return;
49
50 const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
51 if (__sanitizer::is_trivially_destructible<ValueT>::value) {
52 // Use a simpler loop when values don't need destruction.
53 for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P)
54 P->getFirst() = EmptyKey;
55 } else {
56 unsigned NumEntries = getNumEntries();
57 for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) {
58 if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey)) {
59 if (!KeyInfoT::isEqual(P->getFirst(), TombstoneKey)) {
60 P->getSecond().~ValueT();
61 --NumEntries;
62 }
63 P->getFirst() = EmptyKey;
64 }
65 }
66 CHECK_EQ(NumEntries, 0);
67 }
68 setNumEntries(0);
69 setNumTombstones(0);
70 }
71
72 /// Return true if the specified key is in the map, false otherwise.
73 bool contains(const KeyT &Key) const { return doFind(Key) != nullptr; }
74
75 /// Return 1 if the specified key is in the map, 0 otherwise.
76 size_type count(const KeyT &Key) const { return contains(Key) ? 1 : 0; }
77
78 value_type *find(const KeyT &Key) { return doFind(Key); }
79 const value_type *find(const KeyT &Key) const { return doFind(Key); }
80
81 /// Alternate version of find() which allows a different, and possibly
82 /// less expensive, key type.
83 /// The DenseMapInfo is responsible for supplying methods
84 /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key
85 /// type used.
86 template <class LookupKeyT>
87 value_type *find_as(const LookupKeyT &Key) {
88 return doFind(Key);
89 }
90 template <class LookupKeyT>
91 const value_type *find_as(const LookupKeyT &Key) const {
92 return doFind(Key);
93 }
94
95 /// lookup - Return the entry for the specified key, or a default
96 /// constructed value if no such entry exists.
97 ValueT lookup(const KeyT &Key) const {
98 if (const BucketT *Bucket = doFind(Key))
99 return Bucket->getSecond();
100 return ValueT();
101 }
102
103 // Inserts key,value pair into the map if the key isn't already in the map.
104 // If the key is already in the map, it returns false and doesn't update the
105 // value.
106 detail::DenseMapPair<value_type *, bool> insert(const value_type &KV) {
107 return try_emplace(KV.first, KV.second);
108 }
109
110 // Inserts key,value pair into the map if the key isn't already in the map.
111 // If the key is already in the map, it returns false and doesn't update the
112 // value.
113 detail::DenseMapPair<value_type *, bool> insert(value_type &&KV) {
114 return try_emplace(__sanitizer::move(KV.first),
115 __sanitizer::move(KV.second));
116 }
117
118 // Inserts key,value pair into the map if the key isn't already in the map.
119 // The value is constructed in-place if the key is not in the map, otherwise
120 // it is not moved.
121 template <typename... Ts>
122 detail::DenseMapPair<value_type *, bool> try_emplace(KeyT &&Key,
123 Ts &&...Args) {
124 BucketT *TheBucket;
125 if (LookupBucketFor(Key, TheBucket))
126 return {TheBucket, false}; // Already in map.
127
128 // Otherwise, insert the new element.
129 TheBucket = InsertIntoBucket(TheBucket, __sanitizer::move(Key),
130 __sanitizer::forward<Ts>(Args)...);
131 return {TheBucket, true};
132 }
133
134 // Inserts key,value pair into the map if the key isn't already in the map.
135 // The value is constructed in-place if the key is not in the map, otherwise
136 // it is not moved.
137 template <typename... Ts>
138 detail::DenseMapPair<value_type *, bool> try_emplace(const KeyT &Key,
139 Ts &&...Args) {
140 BucketT *TheBucket;
141 if (LookupBucketFor(Key, TheBucket))
142 return {TheBucket, false}; // Already in map.
143
144 // Otherwise, insert the new element.
145 TheBucket =
146 InsertIntoBucket(TheBucket, Key, __sanitizer::forward<Ts>(Args)...);
147 return {TheBucket, true};
148 }
149
150 /// Alternate version of insert() which allows a different, and possibly
151 /// less expensive, key type.
152 /// The DenseMapInfo is responsible for supplying methods
153 /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key
154 /// type used.
155 template <typename LookupKeyT>
156 detail::DenseMapPair<value_type *, bool> insert_as(value_type &&KV,
157 const LookupKeyT &Val) {
158 BucketT *TheBucket;
159 if (LookupBucketFor(Val, TheBucket))
160 return {TheBucket, false}; // Already in map.
161
162 // Otherwise, insert the new element.
163 TheBucket =
164 InsertIntoBucketWithLookup(TheBucket, __sanitizer::move(KV.first),
165 __sanitizer::move(KV.second), Val);
166 return {TheBucket, true};
167 }
168
169 bool erase(const KeyT &Val) {
170 BucketT *TheBucket = doFind(Val);
171 if (!TheBucket)
172 return false; // not in map.
173
174 TheBucket->getSecond().~ValueT();
175 TheBucket->getFirst() = getTombstoneKey();
176 decrementNumEntries();
177 incrementNumTombstones();
178 return true;
179 }
180
181 void erase(value_type *I) {
182 CHECK_NE(I, nullptr);
183 BucketT *TheBucket = &*I;
184 TheBucket->getSecond().~ValueT();
185 TheBucket->getFirst() = getTombstoneKey();
186 decrementNumEntries();
187 incrementNumTombstones();
188 }
189
190 value_type &FindAndConstruct(const KeyT &Key) {
191 BucketT *TheBucket;
192 if (LookupBucketFor(Key, TheBucket))
193 return *TheBucket;
194
195 return *InsertIntoBucket(TheBucket, Key);
196 }
197
198 ValueT &operator[](const KeyT &Key) { return FindAndConstruct(Key).second; }
199
200 value_type &FindAndConstruct(KeyT &&Key) {
201 BucketT *TheBucket;
202 if (LookupBucketFor(Key, TheBucket))
203 return *TheBucket;
204
205 return *InsertIntoBucket(TheBucket, __sanitizer::move(Key));
206 }
207
208 ValueT &operator[](KeyT &&Key) {
209 return FindAndConstruct(__sanitizer::move(Key)).second;
210 }
211
212 /// Iterate over active entries of the container.
213 ///
214 /// Function can return fast to stop the process.
215 template <class Fn>
216 void forEach(Fn fn) {
217 const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
218 for (auto *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) {
219 const KeyT K = P->getFirst();
220 if (!KeyInfoT::isEqual(K, EmptyKey) &&
221 !KeyInfoT::isEqual(K, TombstoneKey)) {
222 if (!fn(*P))
223 return;
224 }
225 }
226 }
227
228 template <class Fn>
229 void forEach(Fn fn) const {
230 const_cast<DenseMapBase *>(this)->forEach(
231 [&](const value_type &KV) { return fn(KV); });
232 }
233
234 protected:
235 DenseMapBase() = default;
236
237 void destroyAll() {
238 if (getNumBuckets() == 0) // Nothing to do.
239 return;
240
241 const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
242 for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) {
243 if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey) &&
244 !KeyInfoT::isEqual(P->getFirst(), TombstoneKey))
245 P->getSecond().~ValueT();
246 P->getFirst().~KeyT();
247 }
248 }
249
250 void initEmpty() {
251 setNumEntries(0);
252 setNumTombstones(0);
253
254 CHECK_EQ((getNumBuckets() & (getNumBuckets() - 1)), 0);
255 const KeyT EmptyKey = getEmptyKey();
256 for (BucketT *B = getBuckets(), *E = getBucketsEnd(); B != E; ++B)
257 ::new (&B->getFirst()) KeyT(EmptyKey);
258 }
259
260 /// Returns the number of buckets to allocate to ensure that the DenseMap can
261 /// accommodate \p NumEntries without need to grow().
262 unsigned getMinBucketToReserveForEntries(unsigned NumEntries) {
263 // Ensure that "NumEntries * 4 < NumBuckets * 3"
264 if (NumEntries == 0)
265 return 0;
266 // +1 is required because of the strict equality.
267 // For example if NumEntries is 48, we need to return 401.
268 return RoundUpToPowerOfTwo((NumEntries * 4 / 3 + 1) + /* NextPowerOf2 */ 1);
269 }
270
271 void moveFromOldBuckets(BucketT *OldBucketsBegin, BucketT *OldBucketsEnd) {
272 initEmpty();
273
274 // Insert all the old elements.
275 const KeyT EmptyKey = getEmptyKey();
276 const KeyT TombstoneKey = getTombstoneKey();
277 for (BucketT *B = OldBucketsBegin, *E = OldBucketsEnd; B != E; ++B) {
278 if (!KeyInfoT::isEqual(B->getFirst(), EmptyKey) &&
279 !KeyInfoT::isEqual(B->getFirst(), TombstoneKey)) {
280 // Insert the key/value into the new table.
281 BucketT *DestBucket;
282 bool FoundVal = LookupBucketFor(B->getFirst(), DestBucket);
283 (void)FoundVal; // silence warning.
284 CHECK(!FoundVal);
285 DestBucket->getFirst() = __sanitizer::move(B->getFirst());
286 ::new (&DestBucket->getSecond())
287 ValueT(__sanitizer::move(B->getSecond()));
288 incrementNumEntries();
289
290 // Free the value.
291 B->getSecond().~ValueT();
292 }
293 B->getFirst().~KeyT();
294 }
295 }
296
297 template <typename OtherBaseT>
298 void copyFrom(
299 const DenseMapBase<OtherBaseT, KeyT, ValueT, KeyInfoT, BucketT> &other) {
300 CHECK_NE(&other, this);
301 CHECK_EQ(getNumBuckets(), other.getNumBuckets());
302
303 setNumEntries(other.getNumEntries());
304 setNumTombstones(other.getNumTombstones());
305
306 if (__sanitizer::is_trivially_copyable<KeyT>::value &&
307 __sanitizer::is_trivially_copyable<ValueT>::value)
308 internal_memcpy(reinterpret_cast<void *>(getBuckets()),
309 other.getBuckets(), getNumBuckets() * sizeof(BucketT));
310 else
311 for (uptr i = 0; i < getNumBuckets(); ++i) {
312 ::new (&getBuckets()[i].getFirst())
313 KeyT(other.getBuckets()[i].getFirst());
314 if (!KeyInfoT::isEqual(getBuckets()[i].getFirst(), getEmptyKey()) &&
315 !KeyInfoT::isEqual(getBuckets()[i].getFirst(), getTombstoneKey()))
316 ::new (&getBuckets()[i].getSecond())
317 ValueT(other.getBuckets()[i].getSecond());
318 }
319 }
320
321 static unsigned getHashValue(const KeyT &Val) {
322 return KeyInfoT::getHashValue(Val);
323 }
324
325 template <typename LookupKeyT>
326 static unsigned getHashValue(const LookupKeyT &Val) {
327 return KeyInfoT::getHashValue(Val);
328 }
329
330 static const KeyT getEmptyKey() { return KeyInfoT::getEmptyKey(); }
331
332 static const KeyT getTombstoneKey() { return KeyInfoT::getTombstoneKey(); }
333
334 private:
335 unsigned getNumEntries() const {
336 return static_cast<const DerivedT *>(this)->getNumEntries();
337 }
338
339 void setNumEntries(unsigned Num) {
340 static_cast<DerivedT *>(this)->setNumEntries(Num);
341 }
342
343 void incrementNumEntries() { setNumEntries(getNumEntries() + 1); }
344
345 void decrementNumEntries() { setNumEntries(getNumEntries() - 1); }
346
347 unsigned getNumTombstones() const {
348 return static_cast<const DerivedT *>(this)->getNumTombstones();
349 }
350
351 void setNumTombstones(unsigned Num) {
352 static_cast<DerivedT *>(this)->setNumTombstones(Num);
353 }
354
355 void incrementNumTombstones() { setNumTombstones(getNumTombstones() + 1); }
356
357 void decrementNumTombstones() { setNumTombstones(getNumTombstones() - 1); }
358
359 const BucketT *getBuckets() const {
360 return static_cast<const DerivedT *>(this)->getBuckets();
361 }
362
363 BucketT *getBuckets() { return static_cast<DerivedT *>(this)->getBuckets(); }
364
365 unsigned getNumBuckets() const {
366 return static_cast<const DerivedT *>(this)->getNumBuckets();
367 }
368
369 BucketT *getBucketsEnd() { return getBuckets() + getNumBuckets(); }
370
371 const BucketT *getBucketsEnd() const {
372 return getBuckets() + getNumBuckets();
373 }
374
375 void grow(unsigned AtLeast) { static_cast<DerivedT *>(this)->grow(AtLeast); }
376
377 template <typename KeyArg, typename... ValueArgs>
378 BucketT *InsertIntoBucket(BucketT *TheBucket, KeyArg &&Key,
379 ValueArgs &&...Values) {
380 TheBucket = InsertIntoBucketImpl(Key, Key, TheBucket);
381
382 TheBucket->getFirst() = __sanitizer::forward<KeyArg>(Key);
383 ::new (&TheBucket->getSecond())
384 ValueT(__sanitizer::forward<ValueArgs>(Values)...);
385 return TheBucket;
386 }
387
388 template <typename LookupKeyT>
389 BucketT *InsertIntoBucketWithLookup(BucketT *TheBucket, KeyT &&Key,
390 ValueT &&Value, LookupKeyT &Lookup) {
391 TheBucket = InsertIntoBucketImpl(Key, Lookup, TheBucket);
392
393 TheBucket->getFirst() = __sanitizer::move(Key);
394 ::new (&TheBucket->getSecond()) ValueT(__sanitizer::move(Value));
395 return TheBucket;
396 }
397
398 template <typename LookupKeyT>
399 BucketT *InsertIntoBucketImpl(const KeyT &Key, const LookupKeyT &Lookup,
400 BucketT *TheBucket) {
401 // If the load of the hash table is more than 3/4, or if fewer than 1/8 of
402 // the buckets are empty (meaning that many are filled with tombstones),
403 // grow the table.
404 //
405 // The later case is tricky. For example, if we had one empty bucket with
406 // tons of tombstones, failing lookups (e.g. for insertion) would have to
407 // probe almost the entire table until it found the empty bucket. If the
408 // table completely filled with tombstones, no lookup would ever succeed,
409 // causing infinite loops in lookup.
410 unsigned NewNumEntries = getNumEntries() + 1;
411 unsigned NumBuckets = getNumBuckets();
412 if (UNLIKELY(NewNumEntries * 4 >= NumBuckets * 3)) {
413 this->grow(NumBuckets * 2);
414 LookupBucketFor(Lookup, TheBucket);
415 NumBuckets = getNumBuckets();
416 } else if (UNLIKELY(NumBuckets - (NewNumEntries + getNumTombstones()) <=
417 NumBuckets / 8)) {
418 this->grow(NumBuckets);
419 LookupBucketFor(Lookup, TheBucket);
420 }
421 CHECK(TheBucket);
422
423 // Only update the state after we've grown our bucket space appropriately
424 // so that when growing buckets we have self-consistent entry count.
425 incrementNumEntries();
426
427 // If we are writing over a tombstone, remember this.
428 const KeyT EmptyKey = getEmptyKey();
429 if (!KeyInfoT::isEqual(TheBucket->getFirst(), EmptyKey))
430 decrementNumTombstones();
431
432 return TheBucket;
433 }
434
435 template <typename LookupKeyT>
436 BucketT *doFind(const LookupKeyT &Val) {
437 BucketT *BucketsPtr = getBuckets();
438 const unsigned NumBuckets = getNumBuckets();
439 if (NumBuckets == 0)
440 return nullptr;
441
442 const KeyT EmptyKey = getEmptyKey();
443 unsigned BucketNo = getHashValue(Val) & (NumBuckets - 1);
444 unsigned ProbeAmt = 1;
445 while (true) {
446 BucketT *Bucket = BucketsPtr + BucketNo;
447 if (LIKELY(KeyInfoT::isEqual(Val, Bucket->getFirst())))
448 return Bucket;
449 if (LIKELY(KeyInfoT::isEqual(Bucket->getFirst(), EmptyKey)))
450 return nullptr;
451
452 // Otherwise, it's a hash collision or a tombstone, continue quadratic
453 // probing.
454 BucketNo += ProbeAmt++;
455 BucketNo &= NumBuckets - 1;
456 }
457 }
458
459 template <typename LookupKeyT>
460 const BucketT *doFind(const LookupKeyT &Val) const {
461 return const_cast<DenseMapBase *>(this)->doFind(Val);
462 }
463
464 /// LookupBucketFor - Lookup the appropriate bucket for Val, returning it in
465 /// FoundBucket. If the bucket contains the key and a value, this returns
466 /// true, otherwise it returns a bucket with an empty marker or tombstone and
467 /// returns false.
468 template <typename LookupKeyT>
469 bool LookupBucketFor(const LookupKeyT &Val,
470 const BucketT *&FoundBucket) const {
471 const BucketT *BucketsPtr = getBuckets();
472 const unsigned NumBuckets = getNumBuckets();
473
474 if (NumBuckets == 0) {
475 FoundBucket = nullptr;
476 return false;
477 }
478
479 // FoundTombstone - Keep track of whether we find a tombstone while probing.
480 const BucketT *FoundTombstone = nullptr;
481 const KeyT EmptyKey = getEmptyKey();
482 const KeyT TombstoneKey = getTombstoneKey();
483 CHECK(!KeyInfoT::isEqual(Val, EmptyKey));
484 CHECK(!KeyInfoT::isEqual(Val, TombstoneKey));
485
486 unsigned BucketNo = getHashValue(Val) & (NumBuckets - 1);
487 unsigned ProbeAmt = 1;
488 while (true) {
489 const BucketT *ThisBucket = BucketsPtr + BucketNo;
490 // Found Val's bucket? If so, return it.
491 if (LIKELY(KeyInfoT::isEqual(Val, ThisBucket->getFirst()))) {
492 FoundBucket = ThisBucket;
493 return true;
494 }
495
496 // If we found an empty bucket, the key doesn't exist in the set.
497 // Insert it and return the default value.
498 if (LIKELY(KeyInfoT::isEqual(ThisBucket->getFirst(), EmptyKey))) {
499 // If we've already seen a tombstone while probing, fill it in instead
500 // of the empty bucket we eventually probed to.
501 FoundBucket = FoundTombstone ? FoundTombstone : ThisBucket;
502 return false;
503 }
504
505 // If this is a tombstone, remember it. If Val ends up not in the map, we
506 // prefer to return it than something that would require more probing.
507 if (KeyInfoT::isEqual(ThisBucket->getFirst(), TombstoneKey) &&
508 !FoundTombstone)
509 FoundTombstone = ThisBucket; // Remember the first tombstone found.
510
511 // Otherwise, it's a hash collision or a tombstone, continue quadratic
512 // probing.
513 BucketNo += ProbeAmt++;
514 BucketNo &= (NumBuckets - 1);
515 }
516 }
517
518 template <typename LookupKeyT>
519 bool LookupBucketFor(const LookupKeyT &Val, BucketT *&FoundBucket) {
520 const BucketT *ConstFoundBucket;
521 bool Result = const_cast<const DenseMapBase *>(this)->LookupBucketFor(
522 Val, ConstFoundBucket);
523 FoundBucket = const_cast<BucketT *>(ConstFoundBucket);
524 return Result;
525 }
526
527 public:
528 /// Return the approximate size (in bytes) of the actual map.
529 /// This is just the raw memory used by DenseMap.
530 /// If entries are pointers to objects, the size of the referenced objects
531 /// are not included.
532 uptr getMemorySize() const {
533 return RoundUpTo(getNumBuckets() * sizeof(BucketT), GetPageSizeCached());
534 }
535};
536
537/// Equality comparison for DenseMap.
538///
539/// Iterates over elements of LHS confirming that each (key, value) pair in LHS
540/// is also in RHS, and that no additional pairs are in RHS.
541/// Equivalent to N calls to RHS.find and N value comparisons. Amortized
542/// complexity is linear, worst case is O(N^2) (if every hash collides).
543template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT,
544 typename BucketT>
545bool operator==(
546 const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &LHS,
547 const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &RHS) {
548 if (LHS.size() != RHS.size())
549 return false;
550
551 bool R = true;
552 LHS.forEach(
553 [&](const typename DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT,
554 BucketT>::value_type &KV) -> bool {
555 const auto *I = RHS.find(KV.first);
556 if (!I || I->second != KV.second) {
557 R = false;
558 return false;
559 }
560 return true;
561 });
562
563 return R;
564}
565
566/// Inequality comparison for DenseMap.
567///
568/// Equivalent to !(LHS == RHS). See operator== for performance notes.
569template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT,
570 typename BucketT>
571bool operator!=(
572 const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &LHS,
573 const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &RHS) {
574 return !(LHS == RHS);
575}
576
577template <typename KeyT, typename ValueT,
578 typename KeyInfoT = DenseMapInfo<KeyT>,
579 typename BucketT = detail::DenseMapPair<KeyT, ValueT>>
580class DenseMap : public DenseMapBase<DenseMap<KeyT, ValueT, KeyInfoT, BucketT>,
581 KeyT, ValueT, KeyInfoT, BucketT> {
582 friend class DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT, BucketT>;
583
584 // Lift some types from the dependent base class into this class for
585 // simplicity of referring to them.
586 using BaseT = DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT, BucketT>;
587
588 BucketT *Buckets = nullptr;
589 unsigned NumEntries = 0;
590 unsigned NumTombstones = 0;
591 unsigned NumBuckets = 0;
592
593 public:
594 /// Create a DenseMap with an optional \p InitialReserve that guarantee that
595 /// this number of elements can be inserted in the map without grow()
596 explicit DenseMap(unsigned InitialReserve) { init(InitialReserve); }
597 constexpr DenseMap() = default;
598
599 DenseMap(const DenseMap &other) : BaseT() {
600 init(0);
601 copyFrom(other);
602 }
603
604 DenseMap(DenseMap &&other) : BaseT() {
605 init(0);
606 swap(other);
607 }
608
609 ~DenseMap() {
610 this->destroyAll();
611 deallocate_buffer(Buckets, sizeof(BucketT) * NumBuckets);
612 }
613
614 void swap(DenseMap &RHS) {
615 Swap(Buckets, RHS.Buckets);
616 Swap(NumEntries, RHS.NumEntries);
617 Swap(NumTombstones, RHS.NumTombstones);
618 Swap(NumBuckets, RHS.NumBuckets);
619 }
620
621 DenseMap &operator=(const DenseMap &other) {
622 if (&other != this)
623 copyFrom(other);
624 return *this;
625 }
626
627 DenseMap &operator=(DenseMap &&other) {
628 this->destroyAll();
629 deallocate_buffer(Buckets, sizeof(BucketT) * NumBuckets, alignof(BucketT));
630 init(0);
631 swap(other);
632 return *this;
633 }
634
635 void copyFrom(const DenseMap &other) {
636 this->destroyAll();
637 deallocate_buffer(Buckets, sizeof(BucketT) * NumBuckets);
638 if (allocateBuckets(other.NumBuckets)) {
639 this->BaseT::copyFrom(other);
640 } else {
641 NumEntries = 0;
642 NumTombstones = 0;
643 }
644 }
645
646 void init(unsigned InitNumEntries) {
647 auto InitBuckets = BaseT::getMinBucketToReserveForEntries(InitNumEntries);
648 if (allocateBuckets(InitBuckets)) {
649 this->BaseT::initEmpty();
650 } else {
651 NumEntries = 0;
652 NumTombstones = 0;
653 }
654 }
655
656 void grow(unsigned AtLeast) {
657 unsigned OldNumBuckets = NumBuckets;
658 BucketT *OldBuckets = Buckets;
659
660 allocateBuckets(RoundUpToPowerOfTwo(Max<unsigned>(64, AtLeast)));
661 CHECK(Buckets);
662 if (!OldBuckets) {
663 this->BaseT::initEmpty();
664 return;
665 }
666
667 this->moveFromOldBuckets(OldBuckets, OldBuckets + OldNumBuckets);
668
669 // Free the old table.
670 deallocate_buffer(OldBuckets, sizeof(BucketT) * OldNumBuckets);
671 }
672
673 private:
674 unsigned getNumEntries() const { return NumEntries; }
675
676 void setNumEntries(unsigned Num) { NumEntries = Num; }
677
678 unsigned getNumTombstones() const { return NumTombstones; }
679
680 void setNumTombstones(unsigned Num) { NumTombstones = Num; }
681
682 BucketT *getBuckets() const { return Buckets; }
683
684 unsigned getNumBuckets() const { return NumBuckets; }
685
686 bool allocateBuckets(unsigned Num) {
687 NumBuckets = Num;
688 if (NumBuckets == 0) {
689 Buckets = nullptr;
690 return false;
691 }
692
693 uptr Size = sizeof(BucketT) * NumBuckets;
694 if (Size * 2 <= GetPageSizeCached()) {
695 // We always allocate at least a page, so use entire space.
696 unsigned Log2 = MostSignificantSetBitIndex(GetPageSizeCached() / Size);
697 Size <<= Log2;
698 NumBuckets <<= Log2;
699 CHECK_EQ(Size, sizeof(BucketT) * NumBuckets);
700 CHECK_GT(Size * 2, GetPageSizeCached());
701 }
702 Buckets = static_cast<BucketT *>(allocate_buffer(Size));
703 return true;
704 }
705
706 static void *allocate_buffer(uptr Size) {
707 return MmapOrDie(RoundUpTo(Size, GetPageSizeCached()), "DenseMap");
708 }
709
710 static void deallocate_buffer(void *Ptr, uptr Size) {
711 UnmapOrDie(Ptr, RoundUpTo(Size, GetPageSizeCached()));
712 }
713};
714
715} // namespace __sanitizer
716
717#endif // SANITIZER_DENSE_MAP_H