table: add CS policy LRU

Change-Id: Ief9e3d993782730069cedc8a99b8011d5d18ce7c
refs: #2219
diff --git a/daemon/table/cs-policy-lru.cpp b/daemon/table/cs-policy-lru.cpp
new file mode 100644
index 0000000..dad467d
--- /dev/null
+++ b/daemon/table/cs-policy-lru.cpp
@@ -0,0 +1,94 @@
+/* -*- 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/>.
+ */
+
+#include "cs-policy-lru.hpp"
+#include "cs.hpp"
+#include <ndn-cxx/util/signal.hpp>
+
+namespace nfd {
+namespace cs {
+namespace lru {
+
+const std::string LruPolicy::POLICY_NAME = "lru";
+
+LruPolicy::LruPolicy()
+  : Policy(POLICY_NAME)
+{
+}
+
+void
+LruPolicy::doAfterInsert(iterator i)
+{
+  this->insertToQueue(i, true);
+  this->evictEntries();
+}
+
+void
+LruPolicy::doAfterRefresh(iterator i)
+{
+  this->insertToQueue(i, false);
+}
+
+void
+LruPolicy::doBeforeErase(iterator i)
+{
+  m_queue.get<1>().erase(i);
+}
+
+void
+LruPolicy::doBeforeUse(iterator i)
+{
+  this->insertToQueue(i, false);
+}
+
+void
+LruPolicy::evictEntries()
+{
+  BOOST_ASSERT(this->getCs() != nullptr);
+  while (this->getCs()->size() > this->getLimit()) {
+    BOOST_ASSERT(!m_queue.empty());
+    iterator i = m_queue.front();
+    m_queue.pop_front();
+    this->emitSignal(beforeEvict, i);
+  }
+}
+
+void
+LruPolicy::insertToQueue(iterator i, bool isNewEntry)
+{
+  Queue::iterator it;
+  bool isNew = false;
+  // push_back only if iterator i does not exist
+  std::tie(it, isNew) = m_queue.push_back(i);
+
+  BOOST_ASSERT(isNew == isNewEntry);
+  if (!isNewEntry) {
+    m_queue.relocate(m_queue.end(), it);
+  }
+}
+
+} // namespace lru
+} // namespace cs
+} // namespace nfd
diff --git a/daemon/table/cs-policy-lru.hpp b/daemon/table/cs-policy-lru.hpp
new file mode 100644
index 0000000..bea845c
--- /dev/null
+++ b/daemon/table/cs-policy-lru.hpp
@@ -0,0 +1,106 @@
+/* -*- 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_DAEMON_TABLE_CS_POLICY_LRU_HPP
+#define NFD_DAEMON_TABLE_CS_POLICY_LRU_HPP
+
+#include "cs-policy.hpp"
+#include "common.hpp"
+
+#include <boost/multi_index_container.hpp>
+#include <boost/multi_index/sequenced_index.hpp>
+#include <boost/multi_index/hashed_index.hpp>
+
+namespace nfd {
+namespace cs {
+namespace lru {
+
+struct EntryItComparator
+{
+  bool
+  operator()(const iterator& a, const iterator& b) const
+  {
+    return *a < *b;
+  }
+};
+
+typedef boost::multi_index_container<
+    iterator,
+    boost::multi_index::indexed_by<
+      boost::multi_index::sequenced<>,
+      boost::multi_index::ordered_unique<
+        boost::multi_index::identity<iterator>, EntryItComparator
+      >
+    >
+  > Queue;
+
+/** \brief LRU cs replacement policy
+ *
+ * The least recently used entries get removed first.
+ * Everytime when any entry is used or refreshed, Policy should witness the usage
+ * of it.
+ */
+class LruPolicy : public Policy
+{
+public:
+  LruPolicy();
+
+public:
+  static const std::string POLICY_NAME;
+
+private:
+  virtual void
+  doAfterInsert(iterator i) DECL_OVERRIDE;
+
+  virtual void
+  doAfterRefresh(iterator i) DECL_OVERRIDE;
+
+  virtual void
+  doBeforeErase(iterator i) DECL_OVERRIDE;
+
+  virtual void
+  doBeforeUse(iterator i) DECL_OVERRIDE;
+
+  virtual void
+  evictEntries() DECL_OVERRIDE;
+
+private:
+  /** \brief moves an entry to the end of queue
+   */
+  void
+  insertToQueue(iterator i, bool isNewEntry);
+
+private:
+  Queue m_queue;
+};
+
+} // namespace lru
+
+using lru::LruPolicy;
+
+} // namespace cs
+} // namespace nfd
+
+#endif // NFD_DAEMON_TABLE_CS_POLICY_LRU_HPP
\ No newline at end of file
diff --git a/tests/daemon/table/cs-policy-lru.t.cpp b/tests/daemon/table/cs-policy-lru.t.cpp
new file mode 100644
index 0000000..a690f33
--- /dev/null
+++ b/tests/daemon/table/cs-policy-lru.t.cpp
@@ -0,0 +1,92 @@
+/* -*- 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/>.
+ */
+
+#include "table/cs.hpp"
+#include "table/cs-policy-lru.hpp"
+#include <ndn-cxx/util/crypto.hpp>
+
+#include "tests/test-common.hpp"
+
+namespace nfd {
+namespace cs {
+namespace tests {
+
+using namespace nfd::tests;
+using ndn::nfd::LocalControlHeader;
+
+BOOST_AUTO_TEST_SUITE(CsLru)
+
+BOOST_FIXTURE_TEST_CASE(EvictOneLRU, UnitTestTimeFixture)
+{
+  Cs cs(3);
+  cs.setPolicy(unique_ptr<Policy>(new LruPolicy()));
+
+  cs.insert(*makeData("ndn:/A"));
+  cs.insert(*makeData("ndn:/B"));
+  cs.insert(*makeData("ndn:/C"));
+  BOOST_CHECK_EQUAL(cs.size(), 3);
+
+  // evict A
+  cs.insert(*makeData("ndn:/D"));
+  BOOST_CHECK_EQUAL(cs.size(), 3);
+  cs.find(Interest("ndn:/A"),
+          bind([] { BOOST_CHECK(false); }),
+          bind([] { BOOST_CHECK(true); }));
+
+  // use C then B
+  cs.find(Interest("ndn:/C"),
+          bind([] { BOOST_CHECK(true); }),
+          bind([] { BOOST_CHECK(false); }));
+  cs.find(Interest("ndn:/B"),
+          bind([] { BOOST_CHECK(true); }),
+          bind([] { BOOST_CHECK(false); }));
+
+  // evict D then C
+  cs.insert(*makeData("ndn:/E"));
+  BOOST_CHECK_EQUAL(cs.size(), 3);
+  cs.find(Interest("ndn:/D"),
+          bind([] { BOOST_CHECK(false); }),
+          bind([] { BOOST_CHECK(true); }));
+  cs.insert(*makeData("ndn:/F"));
+  BOOST_CHECK_EQUAL(cs.size(), 3);
+  cs.find(Interest("ndn:/C"),
+          bind([] { BOOST_CHECK(false); }),
+          bind([] { BOOST_CHECK(true); }));
+
+  // refresh B
+  cs.insert(*makeData("ndn:/B"));
+  // evict E
+  cs.insert(*makeData("ndn:/G"));
+  BOOST_CHECK_EQUAL(cs.size(), 3);
+  cs.find(Interest("ndn:/E"),
+          bind([] { BOOST_CHECK(false); }),
+          bind([] { BOOST_CHECK(true); }));
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+} // namespace tests
+} // namespace cs
+} // namespace nfd