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-rw-r--r-- | gfx/angle/checkout/src/common/CircularBuffer.h | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/common/CircularBuffer.h b/gfx/angle/checkout/src/common/CircularBuffer.h new file mode 100644 index 0000000000..3ff5f14d1b --- /dev/null +++ b/gfx/angle/checkout/src/common/CircularBuffer.h @@ -0,0 +1,175 @@ +// +// Copyright 2021 The ANGLE Project Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. +// +// CircularBuffer.h: +// An array class with an index that loops through the elements. +// + +#ifndef COMMON_CIRCULARBUFFER_H_ +#define COMMON_CIRCULARBUFFER_H_ + +#include "common/debug.h" + +#include <algorithm> +#include <array> + +namespace angle +{ +template <class T, size_t N, class Storage = std::array<T, N>> +class CircularBuffer final +{ + public: + using value_type = typename Storage::value_type; + using size_type = typename Storage::size_type; + using reference = typename Storage::reference; + using const_reference = typename Storage::const_reference; + using pointer = typename Storage::pointer; + using const_pointer = typename Storage::const_pointer; + using iterator = typename Storage::iterator; + using const_iterator = typename Storage::const_iterator; + + CircularBuffer(); + CircularBuffer(const value_type &value); + + CircularBuffer(const CircularBuffer<T, N, Storage> &other); + CircularBuffer(CircularBuffer<T, N, Storage> &&other); + + CircularBuffer<T, N, Storage> &operator=(const CircularBuffer<T, N, Storage> &other); + CircularBuffer<T, N, Storage> &operator=(CircularBuffer<T, N, Storage> &&other); + + ~CircularBuffer(); + + // begin() and end() are used to iterate over all elements regardless of the current position of + // the front of the buffer. Useful for initialization and clean up, as otherwise only the front + // element is expected to be accessed. + iterator begin(); + const_iterator begin() const; + + iterator end(); + const_iterator end() const; + + size_type size() const; + + reference front(); + const_reference front() const; + + void swap(CircularBuffer<T, N, Storage> &other); + + // Move the front forward to the next index, looping back to the beginning if the end of the + // array is reached. + void next(); + + private: + Storage mData; + size_type mFrontIndex; +}; + +template <class T, size_t N, class Storage> +CircularBuffer<T, N, Storage>::CircularBuffer() : mFrontIndex(0) +{} + +template <class T, size_t N, class Storage> +CircularBuffer<T, N, Storage>::CircularBuffer(const value_type &value) : CircularBuffer() +{ + std::fill(begin(), end(), value); +} + +template <class T, size_t N, class Storage> +CircularBuffer<T, N, Storage>::CircularBuffer(const CircularBuffer<T, N, Storage> &other) +{ + *this = other; +} + +template <class T, size_t N, class Storage> +CircularBuffer<T, N, Storage>::CircularBuffer(CircularBuffer<T, N, Storage> &&other) + : CircularBuffer() +{ + swap(other); +} + +template <class T, size_t N, class Storage> +CircularBuffer<T, N, Storage> &CircularBuffer<T, N, Storage>::operator=( + const CircularBuffer<T, N, Storage> &other) +{ + std::copy(other.begin(), other.end(), begin()); + mFrontIndex = other.mFrontIndex; + return *this; +} + +template <class T, size_t N, class Storage> +CircularBuffer<T, N, Storage> &CircularBuffer<T, N, Storage>::operator=( + CircularBuffer<T, N, Storage> &&other) +{ + swap(other); + return *this; +} + +template <class T, size_t N, class Storage> +CircularBuffer<T, N, Storage>::~CircularBuffer() = default; + +template <class T, size_t N, class Storage> +ANGLE_INLINE typename CircularBuffer<T, N, Storage>::iterator CircularBuffer<T, N, Storage>::begin() +{ + return mData.begin(); +} + +template <class T, size_t N, class Storage> +ANGLE_INLINE typename CircularBuffer<T, N, Storage>::const_iterator +CircularBuffer<T, N, Storage>::begin() const +{ + return mData.begin(); +} + +template <class T, size_t N, class Storage> +ANGLE_INLINE typename CircularBuffer<T, N, Storage>::iterator CircularBuffer<T, N, Storage>::end() +{ + return mData.end(); +} + +template <class T, size_t N, class Storage> +ANGLE_INLINE typename CircularBuffer<T, N, Storage>::const_iterator +CircularBuffer<T, N, Storage>::end() const +{ + return mData.end(); +} + +template <class T, size_t N, class Storage> +ANGLE_INLINE typename CircularBuffer<T, N, Storage>::size_type CircularBuffer<T, N, Storage>::size() + const +{ + return N; +} + +template <class T, size_t N, class Storage> +ANGLE_INLINE typename CircularBuffer<T, N, Storage>::reference +CircularBuffer<T, N, Storage>::front() +{ + ASSERT(mFrontIndex < size()); + return mData[mFrontIndex]; +} + +template <class T, size_t N, class Storage> +ANGLE_INLINE typename CircularBuffer<T, N, Storage>::const_reference +CircularBuffer<T, N, Storage>::front() const +{ + ASSERT(mFrontIndex < size()); + return mData[mFrontIndex]; +} + +template <class T, size_t N, class Storage> +void CircularBuffer<T, N, Storage>::swap(CircularBuffer<T, N, Storage> &other) +{ + std::swap(mData, other.mData); + std::swap(mFrontIndex, other.mFrontIndex); +} + +template <class T, size_t N, class Storage> +void CircularBuffer<T, N, Storage>::next() +{ + mFrontIndex = (mFrontIndex + 1) % size(); +} +} // namespace angle + +#endif // COMMON_CIRCULARBUFFER_H_ |