core: Add core module for shared code
This commit also makes log4cxx dependency required
diff --git a/core/random-interval-generator.hpp b/core/random-interval-generator.hpp
new file mode 100644
index 0000000..ceeef60
--- /dev/null
+++ b/core/random-interval-generator.hpp
@@ -0,0 +1,108 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016, Regents of the University of California.
+ *
+ * This file is part of ChronoShare, a decentralized file sharing application over NDN.
+ *
+ * ChronoShare 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.
+ *
+ * ChronoShare 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 copies of the GNU General Public License along with
+ * ChronoShare, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ChronoShare authors and contributors.
+ */
+
+#ifndef CHRONOSHARE_CORE_RANDOM_INTERVAL_GENERATOR_HPP
+#define CHRONOSHARE_CORE_RANDOM_INTERVAL_GENERATOR_HPP
+
+#include "interval-generator.hpp"
+
+#include <boost/date_time/posix_time/posix_time_types.hpp>
+#include <boost/random/mersenne_twister.hpp>
+#include <boost/random/uniform_real.hpp>
+#include <boost/random/variate_generator.hpp>
+
+namespace ndn {
+namespace chronoshare {
+
+// generates intervals with uniform distribution
+class RandomIntervalGenerator : public IntervalGenerator
+{
+public:
+ enum class Direction {
+ UP = 1,
+ DOWN = 2,
+ EVEN = 3
+ };
+
+public:
+ // percent is random-range/interval; e.g. if interval is 10 and you wish the random-range to be 2
+ // e.g. 9 ~ 11, percent = 0.2
+ // direction shifts the random range; e.g. in the above example, UP would produce a range of
+ // 10 ~ 12, DOWN of 8 ~ 10, and EVEN of 9 ~ 11
+ RandomIntervalGenerator(double interval, double percent, Direction direction = Direction::EVEN)
+ // : m_rng(time(NULL))
+ : m_rng(static_cast<int>(
+ boost::posix_time::microsec_clock::local_time().time_of_day().total_nanoseconds())),
+ m_dist(0.0, fractional(percent)),
+ m_random(m_rng, m_dist),
+ m_direction(direction),
+ m_percent(percent),
+ m_interval(interval)
+ {
+ }
+
+ virtual ~RandomIntervalGenerator()
+ {
+ }
+
+ virtual double
+ nextInterval()
+ {
+ double percent = m_random();
+ double interval = m_interval;
+ switch (m_direction) {
+ case Direction::UP:
+ interval = m_interval * (1.0 + percent);
+ break;
+ case Direction::DOWN:
+ interval = m_interval * (1.0 - percent);
+ break;
+ case Direction::EVEN:
+ interval = m_interval * (1.0 - m_percent / 2.0 + percent);
+ break;
+ default:
+ break;
+ }
+
+ return interval;
+ }
+
+private:
+ inline double
+ fractional(double x)
+ {
+ double dummy;
+ return std::abs<double>(modf(x, &dummy));
+ }
+
+private:
+ typedef boost::mt19937 RNG_TYPE;
+ RNG_TYPE m_rng;
+ boost::uniform_real<> m_dist;
+ boost::variate_generator<RNG_TYPE&, boost::uniform_real<>> m_random;
+ Direction m_direction;
+ double m_percent;
+ double m_interval;
+};
+
+} // chronoshare
+} // ndn
+
+#endif // CHRONOSHARE_CORE_RANDOM_INTERVAL_GENERATOR_HPP