1 /* 2 * Copyright (C) 2015 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 #ifndef RINGBUFFER_H_ 17 #define RINGBUFFER_H_ 18 19 #include "utils/Macros.h" 20 21 #include <stddef.h> 22 23 namespace android { 24 namespace uirenderer { 25 26 template<class T, size_t SIZE> 27 class RingBuffer { 28 PREVENT_COPY_AND_ASSIGN(RingBuffer); 29 30 public: 31 RingBuffer() {} 32 ~RingBuffer() {} 33 34 constexpr size_t capacity() const { return SIZE; } 35 size_t size() const { return mCount; } 36 37 T& next() { 38 mHead = (mHead + 1) % SIZE; 39 if (mCount < SIZE) { 40 mCount++; 41 } 42 return mBuffer[mHead]; 43 } 44 45 T& front() { 46 return (*this)[0]; 47 } 48 49 T& back() { 50 return (*this)[size() - 1]; 51 } 52 53 T& operator[](size_t index) { 54 return mBuffer[(mHead + index + 1) % mCount]; 55 } 56 57 const T& operator[](size_t index) const { 58 return mBuffer[(mHead + index + 1) % mCount]; 59 } 60 61 void clear() { 62 mCount = 0; 63 mHead = -1; 64 } 65 66 private: 67 T mBuffer[SIZE]; 68 int mHead = -1; 69 size_t mCount = 0; 70 }; 71 72 }; // namespace uirenderer 73 }; // namespace android 74 75 #endif /* RINGBUFFER_H_ */ 76
