1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_LIBARTBASE_BASE_HASH_MAP_H_ 18 #define ART_LIBARTBASE_BASE_HASH_MAP_H_ 19 20 #include <utility> 21 22 #include "hash_set.h" 23 24 namespace art { 25 26 template <typename Key, typename Value, typename HashFn> 27 class HashMapHashWrapper { 28 public: operator()29 size_t operator()(const Key& key) const { 30 return hash_fn_(key); 31 } 32 operator()33 size_t operator()(const std::pair<Key, Value>& pair) const { 34 return hash_fn_(pair.first); 35 } 36 37 private: 38 HashFn hash_fn_; 39 }; 40 41 template <typename Key, typename Value, typename PredFn> 42 class HashMapPredWrapper { 43 public: operator()44 bool operator()(const std::pair<Key, Value>& a, const std::pair<Key, Value>& b) const { 45 return pred_fn_(a.first, b.first); 46 } 47 48 template <typename Element> operator()49 bool operator()(const std::pair<Key, Value>& a, const Element& element) const { 50 return pred_fn_(a.first, element); 51 } 52 53 private: 54 PredFn pred_fn_; 55 }; 56 57 template <typename Key, typename Value> 58 class DefaultMapEmptyFn { 59 public: MakeEmpty(std::pair<Key,Value> & item)60 void MakeEmpty(std::pair<Key, Value>& item) const { 61 item = std::pair<Key, Value>(); 62 } IsEmpty(const std::pair<Key,Value> & item)63 bool IsEmpty(const std::pair<Key, Value>& item) const { 64 return item.first == Key(); 65 } 66 }; 67 68 template <class Key, 69 class Value, 70 class EmptyFn = DefaultMapEmptyFn<Key, Value>, 71 class HashFn = DefaultHashFn<Key>, 72 class Pred = DefaultPred<Key>, 73 class Alloc = std::allocator<std::pair<Key, Value>>> 74 class HashMap : public HashSet<std::pair<Key, Value>, 75 EmptyFn, 76 HashMapHashWrapper<Key, Value, HashFn>, 77 HashMapPredWrapper<Key, Value, Pred>, 78 Alloc> { 79 private: 80 using Base = HashSet<std::pair<Key, Value>, 81 EmptyFn, 82 HashMapHashWrapper<Key, Value, HashFn>, 83 HashMapPredWrapper<Key, Value, Pred>, 84 Alloc>; 85 86 public: 87 // Inherit constructors. 88 using Base::Base; 89 90 // Used to insert a new mapping. Overwrite(const Key & k,const Value & v)91 typename Base::iterator Overwrite(const Key& k, const Value& v) { 92 auto res = Base::insert({ k, v }).first; 93 *res = { k, v }; 94 return res; 95 } 96 }; 97 98 } // namespace art 99 100 #endif // ART_LIBARTBASE_BASE_HASH_MAP_H_ 101