mirror of
https://github.com/badaix/snapcast.git
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129 lines
2.6 KiB
C++
129 lines
2.6 KiB
C++
/***
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This file is part of snapcast
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Copyright (C) 2015 Johannes Pohl
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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***/
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#ifndef DOUBLE_BUFFER_H
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#define DOUBLE_BUFFER_H
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#include<deque>
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#include<algorithm>
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/// Size limited queue
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/**
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* Size limited queue with basic statistic functions:
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* median, mean, percentile
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*/
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template <class T>
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class DoubleBuffer
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{
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public:
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DoubleBuffer(size_t size = 10) : bufferSize(size)
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{
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}
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inline void add(const T& element)
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{
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buffer.push_back(element);
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if (buffer.size() > bufferSize)
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buffer.pop_front();
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}
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/// Median as mean over N values around the median
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T median(unsigned int mean = 1) const
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{
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if (buffer.empty())
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return 0;
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std::deque<T> tmpBuffer(buffer.begin(), buffer.end());
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std::sort(tmpBuffer.begin(), tmpBuffer.end());
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if ((mean <= 1) || (tmpBuffer.size() < mean))
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return tmpBuffer[tmpBuffer.size() / 2];
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else
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{
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unsigned int low = tmpBuffer.size() / 2;
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unsigned int high = low;
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low -= mean/2;
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high += mean/2;
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T result((T)0);
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for (unsigned int i=low; i<=high; ++i)
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{
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result += tmpBuffer[i];
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}
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return result / mean;
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}
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}
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double mean() const
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{
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if (buffer.empty())
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return 0;
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double mean = 0.;
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for (size_t n=0; n<buffer.size(); ++n)
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mean += (float)buffer[n] / (float)buffer.size();
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return mean;
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}
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T percentile(unsigned int percentile) const
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{
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if (buffer.empty())
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return 0;
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std::deque<T> tmpBuffer(buffer.begin(), buffer.end());
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std::sort(tmpBuffer.begin(), tmpBuffer.end());
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return tmpBuffer[(size_t)(tmpBuffer.size() * ((float)percentile / (float)100))];
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}
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inline bool full() const
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{
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return (buffer.size() == bufferSize);
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}
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inline void clear()
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{
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buffer.clear();
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}
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inline size_t size() const
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{
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return buffer.size();
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}
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inline bool empty() const
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{
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return (buffer.size() == 0);
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}
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void setSize(size_t size)
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{
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bufferSize = size;
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}
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const std::deque<T>& getBuffer() const
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{
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return &buffer;
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}
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private:
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size_t bufferSize;
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std::deque<T> buffer;
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};
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#endif
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