Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 1 | //===- llvm/ADT/DenseSet.h - Dense probed hash table ------------*- C++ -*-===// |
| 2 | // |
Andrew Walbran | 16937d0 | 2019-10-22 13:54:20 +0100 | [diff] [blame] | 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 |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | // |
| 9 | // This file defines the DenseSet and SmallDenseSet classes. |
| 10 | // |
| 11 | //===----------------------------------------------------------------------===// |
| 12 | |
| 13 | #ifndef LLVM_ADT_DENSESET_H |
| 14 | #define LLVM_ADT_DENSESET_H |
| 15 | |
| 16 | #include "llvm/ADT/DenseMap.h" |
| 17 | #include "llvm/ADT/DenseMapInfo.h" |
Andrew Walbran | 16937d0 | 2019-10-22 13:54:20 +0100 | [diff] [blame] | 18 | #include "llvm/Support/MathExtras.h" |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 19 | #include "llvm/Support/type_traits.h" |
Andrew Scull | cdfcccc | 2018-10-05 20:58:37 +0100 | [diff] [blame] | 20 | #include <algorithm> |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 21 | #include <cstddef> |
| 22 | #include <initializer_list> |
| 23 | #include <iterator> |
| 24 | #include <utility> |
| 25 | |
| 26 | namespace llvm { |
| 27 | |
| 28 | namespace detail { |
| 29 | |
| 30 | struct DenseSetEmpty {}; |
| 31 | |
| 32 | // Use the empty base class trick so we can create a DenseMap where the buckets |
| 33 | // contain only a single item. |
| 34 | template <typename KeyT> class DenseSetPair : public DenseSetEmpty { |
| 35 | KeyT key; |
| 36 | |
| 37 | public: |
| 38 | KeyT &getFirst() { return key; } |
| 39 | const KeyT &getFirst() const { return key; } |
| 40 | DenseSetEmpty &getSecond() { return *this; } |
| 41 | const DenseSetEmpty &getSecond() const { return *this; } |
| 42 | }; |
| 43 | |
| 44 | /// Base class for DenseSet and DenseSmallSet. |
| 45 | /// |
| 46 | /// MapTy should be either |
| 47 | /// |
| 48 | /// DenseMap<ValueT, detail::DenseSetEmpty, ValueInfoT, |
| 49 | /// detail::DenseSetPair<ValueT>> |
| 50 | /// |
| 51 | /// or the equivalent SmallDenseMap type. ValueInfoT must implement the |
| 52 | /// DenseMapInfo "concept". |
| 53 | template <typename ValueT, typename MapTy, typename ValueInfoT> |
| 54 | class DenseSetImpl { |
| 55 | static_assert(sizeof(typename MapTy::value_type) == sizeof(ValueT), |
| 56 | "DenseMap buckets unexpectedly large!"); |
| 57 | MapTy TheMap; |
| 58 | |
| 59 | template <typename T> |
| 60 | using const_arg_type_t = typename const_pointer_or_const_ref<T>::type; |
| 61 | |
| 62 | public: |
| 63 | using key_type = ValueT; |
| 64 | using value_type = ValueT; |
| 65 | using size_type = unsigned; |
| 66 | |
| 67 | explicit DenseSetImpl(unsigned InitialReserve = 0) : TheMap(InitialReserve) {} |
| 68 | |
Olivier Deprez | f4ef2d0 | 2021-04-20 13:36:24 +0200 | [diff] [blame] | 69 | template <typename InputIt> |
| 70 | DenseSetImpl(const InputIt &I, const InputIt &E) |
| 71 | : DenseSetImpl(PowerOf2Ceil(std::distance(I, E))) { |
| 72 | insert(I, E); |
| 73 | } |
| 74 | |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 75 | DenseSetImpl(std::initializer_list<ValueT> Elems) |
Andrew Walbran | 16937d0 | 2019-10-22 13:54:20 +0100 | [diff] [blame] | 76 | : DenseSetImpl(PowerOf2Ceil(Elems.size())) { |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 77 | insert(Elems.begin(), Elems.end()); |
| 78 | } |
| 79 | |
| 80 | bool empty() const { return TheMap.empty(); } |
| 81 | size_type size() const { return TheMap.size(); } |
| 82 | size_t getMemorySize() const { return TheMap.getMemorySize(); } |
| 83 | |
| 84 | /// Grow the DenseSet so that it has at least Size buckets. Will not shrink |
| 85 | /// the Size of the set. |
| 86 | void resize(size_t Size) { TheMap.resize(Size); } |
| 87 | |
| 88 | /// Grow the DenseSet so that it can contain at least \p NumEntries items |
| 89 | /// before resizing again. |
| 90 | void reserve(size_t Size) { TheMap.reserve(Size); } |
| 91 | |
| 92 | void clear() { |
| 93 | TheMap.clear(); |
| 94 | } |
| 95 | |
| 96 | /// Return 1 if the specified key is in the set, 0 otherwise. |
| 97 | size_type count(const_arg_type_t<ValueT> V) const { |
| 98 | return TheMap.count(V); |
| 99 | } |
| 100 | |
| 101 | bool erase(const ValueT &V) { |
| 102 | return TheMap.erase(V); |
| 103 | } |
| 104 | |
| 105 | void swap(DenseSetImpl &RHS) { TheMap.swap(RHS.TheMap); } |
| 106 | |
| 107 | // Iterators. |
| 108 | |
| 109 | class ConstIterator; |
| 110 | |
| 111 | class Iterator { |
| 112 | typename MapTy::iterator I; |
| 113 | friend class DenseSetImpl; |
| 114 | friend class ConstIterator; |
| 115 | |
| 116 | public: |
| 117 | using difference_type = typename MapTy::iterator::difference_type; |
| 118 | using value_type = ValueT; |
| 119 | using pointer = value_type *; |
| 120 | using reference = value_type &; |
| 121 | using iterator_category = std::forward_iterator_tag; |
| 122 | |
| 123 | Iterator() = default; |
| 124 | Iterator(const typename MapTy::iterator &i) : I(i) {} |
| 125 | |
| 126 | ValueT &operator*() { return I->getFirst(); } |
| 127 | const ValueT &operator*() const { return I->getFirst(); } |
| 128 | ValueT *operator->() { return &I->getFirst(); } |
| 129 | const ValueT *operator->() const { return &I->getFirst(); } |
| 130 | |
| 131 | Iterator& operator++() { ++I; return *this; } |
| 132 | Iterator operator++(int) { auto T = *this; ++I; return T; } |
Olivier Deprez | f4ef2d0 | 2021-04-20 13:36:24 +0200 | [diff] [blame] | 133 | friend bool operator==(const Iterator &X, const Iterator &Y) { |
| 134 | return X.I == Y.I; |
| 135 | } |
| 136 | friend bool operator!=(const Iterator &X, const Iterator &Y) { |
| 137 | return X.I != Y.I; |
| 138 | } |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 139 | }; |
| 140 | |
| 141 | class ConstIterator { |
| 142 | typename MapTy::const_iterator I; |
Andrew Walbran | 3d2c197 | 2020-04-07 12:24:26 +0100 | [diff] [blame] | 143 | friend class DenseSetImpl; |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 144 | friend class Iterator; |
| 145 | |
| 146 | public: |
| 147 | using difference_type = typename MapTy::const_iterator::difference_type; |
| 148 | using value_type = ValueT; |
Andrew Scull | 0372a57 | 2018-11-16 15:47:06 +0000 | [diff] [blame] | 149 | using pointer = const value_type *; |
| 150 | using reference = const value_type &; |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 151 | using iterator_category = std::forward_iterator_tag; |
| 152 | |
| 153 | ConstIterator() = default; |
| 154 | ConstIterator(const Iterator &B) : I(B.I) {} |
| 155 | ConstIterator(const typename MapTy::const_iterator &i) : I(i) {} |
| 156 | |
| 157 | const ValueT &operator*() const { return I->getFirst(); } |
| 158 | const ValueT *operator->() const { return &I->getFirst(); } |
| 159 | |
| 160 | ConstIterator& operator++() { ++I; return *this; } |
| 161 | ConstIterator operator++(int) { auto T = *this; ++I; return T; } |
Olivier Deprez | f4ef2d0 | 2021-04-20 13:36:24 +0200 | [diff] [blame] | 162 | friend bool operator==(const ConstIterator &X, const ConstIterator &Y) { |
| 163 | return X.I == Y.I; |
| 164 | } |
| 165 | friend bool operator!=(const ConstIterator &X, const ConstIterator &Y) { |
| 166 | return X.I != Y.I; |
| 167 | } |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 168 | }; |
| 169 | |
| 170 | using iterator = Iterator; |
| 171 | using const_iterator = ConstIterator; |
| 172 | |
| 173 | iterator begin() { return Iterator(TheMap.begin()); } |
| 174 | iterator end() { return Iterator(TheMap.end()); } |
| 175 | |
| 176 | const_iterator begin() const { return ConstIterator(TheMap.begin()); } |
| 177 | const_iterator end() const { return ConstIterator(TheMap.end()); } |
| 178 | |
| 179 | iterator find(const_arg_type_t<ValueT> V) { return Iterator(TheMap.find(V)); } |
| 180 | const_iterator find(const_arg_type_t<ValueT> V) const { |
| 181 | return ConstIterator(TheMap.find(V)); |
| 182 | } |
| 183 | |
Olivier Deprez | f4ef2d0 | 2021-04-20 13:36:24 +0200 | [diff] [blame] | 184 | /// Check if the set contains the given element. |
| 185 | bool contains(const_arg_type_t<ValueT> V) const { |
| 186 | return TheMap.find(V) != TheMap.end(); |
| 187 | } |
| 188 | |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 189 | /// Alternative version of find() which allows a different, and possibly less |
| 190 | /// expensive, key type. |
| 191 | /// The DenseMapInfo is responsible for supplying methods |
| 192 | /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key type |
| 193 | /// used. |
| 194 | template <class LookupKeyT> |
| 195 | iterator find_as(const LookupKeyT &Val) { |
| 196 | return Iterator(TheMap.find_as(Val)); |
| 197 | } |
| 198 | template <class LookupKeyT> |
| 199 | const_iterator find_as(const LookupKeyT &Val) const { |
| 200 | return ConstIterator(TheMap.find_as(Val)); |
| 201 | } |
| 202 | |
| 203 | void erase(Iterator I) { return TheMap.erase(I.I); } |
| 204 | void erase(ConstIterator CI) { return TheMap.erase(CI.I); } |
| 205 | |
| 206 | std::pair<iterator, bool> insert(const ValueT &V) { |
| 207 | detail::DenseSetEmpty Empty; |
| 208 | return TheMap.try_emplace(V, Empty); |
| 209 | } |
| 210 | |
| 211 | std::pair<iterator, bool> insert(ValueT &&V) { |
| 212 | detail::DenseSetEmpty Empty; |
| 213 | return TheMap.try_emplace(std::move(V), Empty); |
| 214 | } |
| 215 | |
| 216 | /// Alternative version of insert that uses a different (and possibly less |
| 217 | /// expensive) key type. |
| 218 | template <typename LookupKeyT> |
| 219 | std::pair<iterator, bool> insert_as(const ValueT &V, |
| 220 | const LookupKeyT &LookupKey) { |
| 221 | return TheMap.insert_as({V, detail::DenseSetEmpty()}, LookupKey); |
| 222 | } |
| 223 | template <typename LookupKeyT> |
| 224 | std::pair<iterator, bool> insert_as(ValueT &&V, const LookupKeyT &LookupKey) { |
| 225 | return TheMap.insert_as({std::move(V), detail::DenseSetEmpty()}, LookupKey); |
| 226 | } |
| 227 | |
| 228 | // Range insertion of values. |
| 229 | template<typename InputIt> |
| 230 | void insert(InputIt I, InputIt E) { |
| 231 | for (; I != E; ++I) |
| 232 | insert(*I); |
| 233 | } |
| 234 | }; |
| 235 | |
Andrew Walbran | 16937d0 | 2019-10-22 13:54:20 +0100 | [diff] [blame] | 236 | /// Equality comparison for DenseSet. |
| 237 | /// |
| 238 | /// Iterates over elements of LHS confirming that each element is also a member |
| 239 | /// of RHS, and that RHS contains no additional values. |
| 240 | /// Equivalent to N calls to RHS.count. Amortized complexity is linear, worst |
| 241 | /// case is O(N^2) (if every hash collides). |
| 242 | template <typename ValueT, typename MapTy, typename ValueInfoT> |
| 243 | bool operator==(const DenseSetImpl<ValueT, MapTy, ValueInfoT> &LHS, |
| 244 | const DenseSetImpl<ValueT, MapTy, ValueInfoT> &RHS) { |
| 245 | if (LHS.size() != RHS.size()) |
| 246 | return false; |
| 247 | |
| 248 | for (auto &E : LHS) |
| 249 | if (!RHS.count(E)) |
| 250 | return false; |
| 251 | |
| 252 | return true; |
| 253 | } |
| 254 | |
| 255 | /// Inequality comparison for DenseSet. |
| 256 | /// |
| 257 | /// Equivalent to !(LHS == RHS). See operator== for performance notes. |
| 258 | template <typename ValueT, typename MapTy, typename ValueInfoT> |
| 259 | bool operator!=(const DenseSetImpl<ValueT, MapTy, ValueInfoT> &LHS, |
| 260 | const DenseSetImpl<ValueT, MapTy, ValueInfoT> &RHS) { |
| 261 | return !(LHS == RHS); |
| 262 | } |
| 263 | |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 264 | } // end namespace detail |
| 265 | |
| 266 | /// Implements a dense probed hash-table based set. |
| 267 | template <typename ValueT, typename ValueInfoT = DenseMapInfo<ValueT>> |
| 268 | class DenseSet : public detail::DenseSetImpl< |
| 269 | ValueT, DenseMap<ValueT, detail::DenseSetEmpty, ValueInfoT, |
| 270 | detail::DenseSetPair<ValueT>>, |
| 271 | ValueInfoT> { |
| 272 | using BaseT = |
| 273 | detail::DenseSetImpl<ValueT, |
| 274 | DenseMap<ValueT, detail::DenseSetEmpty, ValueInfoT, |
| 275 | detail::DenseSetPair<ValueT>>, |
| 276 | ValueInfoT>; |
| 277 | |
| 278 | public: |
| 279 | using BaseT::BaseT; |
| 280 | }; |
| 281 | |
| 282 | /// Implements a dense probed hash-table based set with some number of buckets |
| 283 | /// stored inline. |
| 284 | template <typename ValueT, unsigned InlineBuckets = 4, |
| 285 | typename ValueInfoT = DenseMapInfo<ValueT>> |
| 286 | class SmallDenseSet |
| 287 | : public detail::DenseSetImpl< |
| 288 | ValueT, SmallDenseMap<ValueT, detail::DenseSetEmpty, InlineBuckets, |
| 289 | ValueInfoT, detail::DenseSetPair<ValueT>>, |
| 290 | ValueInfoT> { |
| 291 | using BaseT = detail::DenseSetImpl< |
| 292 | ValueT, SmallDenseMap<ValueT, detail::DenseSetEmpty, InlineBuckets, |
| 293 | ValueInfoT, detail::DenseSetPair<ValueT>>, |
| 294 | ValueInfoT>; |
| 295 | |
| 296 | public: |
| 297 | using BaseT::BaseT; |
| 298 | }; |
| 299 | |
| 300 | } // end namespace llvm |
| 301 | |
| 302 | #endif // LLVM_ADT_DENSESET_H |