face: LinkService and Transport counters
refs #3177
Change-Id: Idc495c58c3103dae5f01a2b6ebbff47a2c4a5d2b
diff --git a/core/counter.hpp b/core/counter.hpp
new file mode 100644
index 0000000..bb50c66
--- /dev/null
+++ b/core/counter.hpp
@@ -0,0 +1,141 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015, Regents of the University of California,
+ * Arizona Board of Regents,
+ * Colorado State University,
+ * University Pierre & Marie Curie, Sorbonne University,
+ * Washington University in St. Louis,
+ * Beijing Institute of Technology,
+ * The University of Memphis.
+ *
+ * This file is part of NFD (Named Data Networking Forwarding Daemon).
+ * See AUTHORS.md for complete list of NFD authors and contributors.
+ *
+ * NFD 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.
+ *
+ * NFD 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
+ * NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef NFD_CORE_COUNTER_HPP
+#define NFD_CORE_COUNTER_HPP
+
+#include "common.hpp"
+
+namespace nfd {
+
+/** \brief represents a counter that encloses an integer value
+ *
+ * SimpleCounter is noncopyable, because increment should be called on the counter,
+ * not a copy of it; it's implicitly convertible to an integral type to be observed
+ */
+class SimpleCounter
+{
+public:
+ typedef uint64_t rep;
+
+ constexpr
+ SimpleCounter()
+ : m_value(0)
+ {
+ }
+
+ SimpleCounter(const SimpleCounter&) = delete;
+
+ SimpleCounter&
+ operator=(const SimpleCounter&) = delete;
+
+ /** \brief observe the counter
+ */
+ operator rep() const
+ {
+ return m_value;
+ }
+
+ /** \brief replace the counter value
+ */
+ void
+ set(rep value)
+ {
+ m_value = value;
+ }
+
+protected:
+ rep m_value;
+};
+
+/** \brief represents a counter of number of packets
+ *
+ * \warning The counter value may wrap after exceeding the range of underlying integer type.
+ */
+class PacketCounter : public SimpleCounter
+{
+public:
+ /** \brief increment the counter by one
+ */
+ PacketCounter&
+ operator++()
+ {
+ ++m_value;
+ return *this;
+ }
+ // postfix ++ operator is not provided because it's not needed
+};
+
+/** \brief represents a counter of number of bytes
+ *
+ * \warning The counter value may wrap after exceeding the range of underlying integer type.
+ */
+class ByteCounter : public SimpleCounter
+{
+public:
+ /** \brief increase the counter
+ */
+ ByteCounter&
+ operator+=(rep n)
+ {
+ m_value += n;
+ return *this;
+ }
+};
+
+/** \brief provides a counter that observes the size of a table
+ * \tparam T a type that provides a size() const member function
+ */
+template<typename T>
+class SizeCounter
+{
+public:
+ typedef size_t rep;
+
+ constexpr
+ SizeCounter(const T& table)
+ : m_table(table)
+ {
+ }
+
+ SizeCounter(const SizeCounter&) = delete;
+
+ SizeCounter&
+ operator=(const SizeCounter&) = delete;
+
+ /** \brief observe the counter
+ */
+ operator rep() const
+ {
+ return m_table.size();
+ }
+
+private:
+ const T& m_table;
+};
+
+} // namespace nfd
+
+#endif // NFD_CORE_COUNTER_HPP