1 /* 2 * Copyright (C) 2018 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 INCLUDE_PERFETTO_EXT_BASE_SMALL_SET_H_ 18 #define INCLUDE_PERFETTO_EXT_BASE_SMALL_SET_H_ 19 20 #include <array> 21 #include <cstdlib> 22 23 namespace perfetto { 24 25 // Set that can store up to Size items of DataType. 26 // Lookup is O(Size), so it is only usable for very small sets. 27 template <typename DataType, size_t Size> 28 class SmallSet { 29 static_assert(Size < 16, "Do not use SmallSet for many items"); 30 31 public: 32 // Name for consistency with STL. 33 using const_iterator = typename std::array<DataType, Size>::const_iterator; Add(DataType n)34 bool Add(DataType n) { 35 if (Contains(n)) 36 return true; 37 if (filled_ < Size) { 38 arr_[filled_++] = std::move(n); 39 return true; 40 } 41 return false; 42 } 43 Contains(const DataType & n)44 bool Contains(const DataType& n) const { 45 for (size_t i = 0; i < filled_; ++i) { 46 if (arr_[i] == n) 47 return true; 48 } 49 return false; 50 } 51 begin()52 const_iterator begin() const { return arr_.cbegin(); } end()53 const_iterator end() const { 54 return arr_.cbegin() + static_cast<ssize_t>(filled_); 55 } size()56 size_t size() const { return filled_; } 57 58 private: 59 std::array<DataType, Size> arr_; 60 size_t filled_ = 0; 61 }; 62 63 } // namespace perfetto 64 65 #endif // INCLUDE_PERFETTO_EXT_BASE_SMALL_SET_H_ 66