rename some files to snake_case

client/double_buffer.hpp

@@ -0,0 +1,133 @@
+/***
+    This file is part of snapcast
+    Copyright (C) 2014-2019  Johannes Pohl
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#ifndef DOUBLE_BUFFER_H
+#define DOUBLE_BUFFER_H
+
+#include <algorithm>
+#include <deque>
+
+
+/// Size limited queue
+/**
+ * Size limited queue with basic statistic functions:
+ * median, mean, percentile
+ */
+template <class T>
+class DoubleBuffer
+{
+public:
+    DoubleBuffer(size_t size = 10) : bufferSize(size)
+    {
+    }
+
+    inline void add(const T& element)
+    {
+        buffer.push_back(element);
+        if (buffer.size() > bufferSize)
+            buffer.pop_front();
+    }
+
+    inline void add(T&& element)
+    {
+        buffer.push_back(std::move(element));
+        if (buffer.size() > bufferSize)
+            buffer.pop_front();
+    }
+
+    /// Median as mean over N values around the median
+    T median(unsigned int mean = 1) const
+    {
+        if (buffer.empty())
+            return 0;
+        std::deque<T> tmpBuffer(buffer.begin(), buffer.end());
+        std::sort(tmpBuffer.begin(), tmpBuffer.end());
+        if ((mean <= 1) || (tmpBuffer.size() < mean))
+            return tmpBuffer[tmpBuffer.size() / 2];
+        else
+        {
+            unsigned int low = tmpBuffer.size() / 2;
+            unsigned int high = low;
+            low -= mean / 2;
+            high += mean / 2;
+            T result((T)0);
+            for (unsigned int i = low; i <= high; ++i)
+            {
+                result += tmpBuffer[i];
+            }
+            return result / mean;
+        }
+    }
+
+    double mean() const
+    {
+        if (buffer.empty())
+            return 0;
+        double mean = 0.;
+        for (size_t n = 0; n < buffer.size(); ++n)
+            mean += (float)buffer[n] / (float)buffer.size();
+        return mean;
+    }
+
+    T percentile(unsigned int percentile) const
+    {
+        if (buffer.empty())
+            return 0;
+        std::deque<T> tmpBuffer(buffer.begin(), buffer.end());
+        std::sort(tmpBuffer.begin(), tmpBuffer.end());
+        return tmpBuffer[(size_t)(tmpBuffer.size() * ((float)percentile / (float)100))];
+    }
+
+    inline bool full() const
+    {
+        return (buffer.size() == bufferSize);
+    }
+
+    inline void clear()
+    {
+        buffer.clear();
+    }
+
+    inline size_t size() const
+    {
+        return buffer.size();
+    }
+
+    inline bool empty() const
+    {
+        return (buffer.size() == 0);
+    }
+
+    void setSize(size_t size)
+    {
+        bufferSize = size;
+    }
+
+    const std::deque<T>& getBuffer() const
+    {
+        return &buffer;
+    }
+
+private:
+    size_t bufferSize;
+    std::deque<T> buffer;
+};
+
+
+
+#endif