forked from Qortal/Brooklyn
161 lines
4.0 KiB
C++
161 lines
4.0 KiB
C++
//
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// Copyright © 2021 Arm Ltd and Contributors. All rights reserved.
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// SPDX-License-Identifier: MIT
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//
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#pragma once
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template<class T>
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class SlidingWindow
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{
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protected:
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T* m_start = nullptr;
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size_t m_dataSize = 0;
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size_t m_size = 0;
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size_t m_stride = 0;
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size_t m_count = 0;
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public:
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/**
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* Creates the window slider through the given data.
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*
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* @param data pointer to the data to slide through.
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* @param dataSize size in T type elements wise.
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* @param windowSize sliding window size in T type wise elements.
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* @param stride stride size in T type wise elements.
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*/
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SlidingWindow(T* data, size_t dataSize,
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size_t windowSize, size_t stride)
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{
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m_start = data;
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m_dataSize = dataSize;
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m_size = windowSize;
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m_stride = stride;
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}
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SlidingWindow() = default;
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~SlidingWindow() = default;
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/**
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* Get the next data window.
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* @return pointer to the next window, if next window is not available nullptr is returned.
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*/
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virtual T* Next()
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{
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if (HasNext())
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{
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m_count++;
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return m_start + Index() * m_stride;
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}
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else
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{
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return nullptr;
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}
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}
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/**
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* Checks if the next data portion is available.
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* @return true if next data portion is available
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*/
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bool HasNext()
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{
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return this->m_count < 1 + this->FractionalTotalStrides() && (this->NextWindowStartIndex() < this->m_dataSize);
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}
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/**
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* Resest the slider to the initial position.
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*/
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virtual void Reset()
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{
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m_count = 0;
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}
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/**
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* Resest the slider to the initial position.
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*/
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virtual size_t GetWindowSize()
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{
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return m_size;
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}
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/**
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* Resets the slider to the start of the new data.
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* New data size MUST be the same as the old one.
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* @param newStart pointer to the new data to slide through.
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*/
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virtual void Reset(T* newStart)
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{
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m_start = newStart;
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Reset();
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}
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/**
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* Gets current index of the sliding window.
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* @return current position of the sliding window in number of strides
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*/
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size_t Index()
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{
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return m_count == 0? 0: m_count - 1;
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}
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/**
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* Gets the index from the start of the data where the next window will begin.
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* While Index() returns the index of sliding window itself this function returns the index of the data
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* element itself.
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* @return Index from the start of the data where the next sliding window will begin.
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*/
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virtual size_t NextWindowStartIndex()
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{
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return m_count == 0? 0: ((m_count) * m_stride);
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}
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/**
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* Go to given sliding window index.
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* @param index new position of the sliding window. if index is invalid (greater than possible range of strides)
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* then next call to Next() will return nullptr.
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*/
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void FastForward(size_t index)
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{
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m_count = index;
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}
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/**
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* Calculates whole number of times the window can stride through the given data.
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* @return maximum number of strides.
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*/
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size_t TotalStrides()
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{
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if (m_size > m_dataSize)
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{
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return 0;
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}
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return ((m_dataSize - m_size)/m_stride);
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}
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/**
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* Calculates number of times the window can stride through the given data. May not be a whole number.
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* @return Number of strides to cover all data.
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*/
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float FractionalTotalStrides()
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{
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if(this->m_size > this->m_dataSize)
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{
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return this->m_dataSize / this->m_size;
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}
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else
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{
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return ((this->m_dataSize - this->m_size)/ static_cast<float>(this->m_stride));
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}
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}
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/**
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* Calculates the remaining data left to be processed
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* @return The remaining unprocessed data
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*/
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int RemainingData()
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{
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return this->m_dataSize - this->NextWindowStartIndex();
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}
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}; |