| // |
| // Copyright © 2020 Arm Ltd and Contributors. All rights reserved. |
| // SPDX-License-Identifier: MIT |
| // |
| |
| #pragma once |
| |
| template<class T> |
| class SlidingWindow |
| { |
| protected: |
| T* m_start = nullptr; |
| size_t m_dataSize = 0; |
| size_t m_size = 0; |
| size_t m_stride = 0; |
| size_t m_count = 0; |
| public: |
| |
| /** |
| * Creates the window slider through the given data. |
| * |
| * @param data pointer to the data to slide through. |
| * @param dataSize size in T type elements wise. |
| * @param windowSize sliding window size in T type wise elements. |
| * @param stride stride size in T type wise elements. |
| */ |
| SlidingWindow(T* data, size_t dataSize, |
| size_t windowSize, size_t stride) |
| { |
| m_start = data; |
| m_dataSize = dataSize; |
| m_size = windowSize; |
| m_stride = stride; |
| } |
| |
| SlidingWindow() = default; |
| |
| ~SlidingWindow() = default; |
| |
| /** |
| * Get the next data window. |
| * @return pointer to the next window, if next window is not available nullptr is returned. |
| */ |
| virtual T* Next() |
| { |
| if (HasNext()) |
| { |
| m_count++; |
| return m_start + Index() * m_stride; |
| } |
| else |
| { |
| return nullptr; |
| } |
| } |
| |
| /** |
| * Checks if the next data portion is available. |
| * @return true if next data portion is available |
| */ |
| bool HasNext() |
| { |
| return this->m_count < 1 + this->FractionalTotalStrides() && (this->NextWindowStartIndex() < this->m_dataSize); |
| } |
| |
| /** |
| * Resest the slider to the initial position. |
| */ |
| virtual void Reset() |
| { |
| m_count = 0; |
| } |
| |
| /** |
| * Resest the slider to the initial position. |
| */ |
| virtual size_t GetWindowSize() |
| { |
| return m_size; |
| } |
| |
| /** |
| * Resets the slider to the start of the new data. |
| * New data size MUST be the same as the old one. |
| * @param newStart pointer to the new data to slide through. |
| */ |
| virtual void Reset(T* newStart) |
| { |
| m_start = newStart; |
| Reset(); |
| } |
| |
| /** |
| * Gets current index of the sliding window. |
| * @return current position of the sliding window in number of strides |
| */ |
| size_t Index() |
| { |
| return m_count == 0? 0: m_count - 1; |
| } |
| |
| /** |
| * Gets the index from the start of the data where the next window will begin. |
| * While Index() returns the index of sliding window itself this function returns the index of the data |
| * element itself. |
| * @return Index from the start of the data where the next sliding window will begin. |
| */ |
| virtual size_t NextWindowStartIndex() |
| { |
| return m_count == 0? 0: ((m_count) * m_stride); |
| } |
| |
| /** |
| * Go to given sliding window index. |
| * @param index new position of the sliding window. if index is invalid (greater than possible range of strides) |
| * then next call to Next() will return nullptr. |
| */ |
| void FastForward(size_t index) |
| { |
| m_count = index; |
| } |
| |
| /** |
| * Calculates whole number of times the window can stride through the given data. |
| * @return maximum number of strides. |
| */ |
| size_t TotalStrides() |
| { |
| if (m_size > m_dataSize) |
| { |
| return 0; |
| } |
| return ((m_dataSize - m_size)/m_stride); |
| } |
| |
| /** |
| * Calculates number of times the window can stride through the given data. May not be a whole number. |
| * @return Number of strides to cover all data. |
| */ |
| float FractionalTotalStrides() |
| { |
| if(this->m_size > this->m_dataSize) |
| { |
| return this->m_dataSize / this->m_size; |
| } |
| else |
| { |
| return ((this->m_dataSize - this->m_size)/ static_cast<float>(this->m_stride)); |
| } |
| |
| } |
| |
| /** |
| * Calculates the remaining data left to be processed |
| * @return The remaining unprocessed data |
| */ |
| int RemainingData() |
| { |
| return this->m_dataSize - this->NextWindowStartIndex(); |
| } |
| }; |