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 LATINIME_INT_ARRAY_VIEW_H 18 #define LATINIME_INT_ARRAY_VIEW_H 19 20 #include <cstdint> 21 #include <cstdlib> 22 #include <vector> 23 24 #include "defines.h" 25 26 namespace latinime { 27 28 /** 29 * Helper class used to provide a read-only view of a given range of integer array. This class 30 * does not take ownership of the underlying integer array but is designed to be a lightweight 31 * object that obeys value semantics. 32 * 33 * Example: 34 * <code> 35 * bool constinsX(IntArrayView view) { 36 * for (size_t i = 0; i < view.size(); ++i) { 37 * if (view[i] == 'X') { 38 * return true; 39 * } 40 * } 41 * return false; 42 * } 43 * 44 * const int codePointArray[] = { 'A', 'B', 'X', 'Z' }; 45 * auto view = IntArrayView(codePointArray, NELEMS(codePointArray)); 46 * const bool hasX = constinsX(view); 47 * </code> 48 */ 49 class IntArrayView { 50 public: IntArrayView()51 IntArrayView() : mPtr(nullptr), mSize(0) {} 52 IntArrayView(const int * const ptr,const size_t size)53 IntArrayView(const int *const ptr, const size_t size) 54 : mPtr(ptr), mSize(size) {} 55 IntArrayView(const std::vector<int> & vector)56 explicit IntArrayView(const std::vector<int> &vector) 57 : mPtr(vector.data()), mSize(vector.size()) {} 58 59 template <int N> fromFixedSizeArray(const int (& array)[N])60 AK_FORCE_INLINE static IntArrayView fromFixedSizeArray(const int (&array)[N]) { 61 return IntArrayView(array, N); 62 } 63 64 // Returns a view that points one int object. Does not take ownership of the given object. fromObject(const int * const object)65 AK_FORCE_INLINE static IntArrayView fromObject(const int *const object) { 66 return IntArrayView(object, 1); 67 } 68 69 AK_FORCE_INLINE int operator[](const size_t index) const { 70 ASSERT(index < mSize); 71 return mPtr[index]; 72 } 73 empty()74 AK_FORCE_INLINE bool empty() const { 75 return size() == 0; 76 } 77 size()78 AK_FORCE_INLINE size_t size() const { 79 return mSize; 80 } 81 data()82 AK_FORCE_INLINE const int *data() const { 83 return mPtr; 84 } 85 begin()86 AK_FORCE_INLINE const int *begin() const { 87 return mPtr; 88 } 89 end()90 AK_FORCE_INLINE const int *end() const { 91 return mPtr + mSize; 92 } 93 94 private: 95 DISALLOW_ASSIGNMENT_OPERATOR(IntArrayView); 96 97 const int *const mPtr; 98 const size_t mSize; 99 }; 100 101 using WordIdArrayView = IntArrayView; 102 using PtNodePosArrayView = IntArrayView; 103 104 } // namespace latinime 105 #endif // LATINIME_MEMORY_VIEW_H 106