time: Add ability to specialize system and steady clocks
Default implementation is "optimized" to use boost::chrono clocks. When
specialization is used, now() calls are redirected to the virtual
methods of the specified specialization.
This commit also includes an implementation of UnitTestClock that
can be used in unit tests to eliminate dependency on the wall clock.
Change-Id: I7ced774634d90ce32714a71e2a66129cba91b9ae
Refs: #2158
diff --git a/src/util/time-custom-clock.hpp b/src/util/time-custom-clock.hpp
new file mode 100644
index 0000000..066d3e9
--- /dev/null
+++ b/src/util/time-custom-clock.hpp
@@ -0,0 +1,70 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2014 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library 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 Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#ifndef NDN_TIME_CUSTOM_CLOCK_HPP
+#define NDN_TIME_CUSTOM_CLOCK_HPP
+
+#include "time.hpp"
+
+namespace ndn {
+namespace time {
+
+/**
+ * \brief Class implementing custom system or steady clock behavior
+ *
+ * Instance of specialization of this class may be passed to setCustomClocks() free function
+ * in order to change global behavior of system or steady clock.
+ */
+template<typename BaseClock>
+class CustomClock
+{
+public:
+ virtual ~CustomClock()
+ {
+ }
+
+ virtual typename BaseClock::time_point
+ getNow() const = 0;
+
+ virtual std::string
+ getSince() const = 0;
+
+ virtual boost::posix_time::time_duration
+ toPosixDuration(const typename BaseClock::duration& duration) const = 0;
+};
+
+typedef CustomClock<system_clock> CustomSystemClock;
+typedef CustomClock<steady_clock> CustomSteadyClock;
+
+/**
+ * \brief Set custom system and steady clocks
+ *
+ * When \p steadyClock or \p systemClock set to nullptr, the default implementation
+ * of the corresponding clock will be used
+ */
+void
+setCustomClocks(shared_ptr<CustomSteadyClock> steadyClock = nullptr,
+ shared_ptr<CustomSystemClock> systemClock = nullptr);
+
+} // namespace time
+} // namespace ndn
+
+#endif // NDN_TIME_CUSTOM_CLOCK_HPP