model: New content store variations: support for content freshness
The following content store realizations now fully support freshness set
in ContentObjects:
- ns3::ndn::cs::Freshness::Lru
- ns3::ndn::cs::Freshness::Random
- ns3::ndn::cs::Freshness::Fifo
Example ndn-simple-with-content-freshness demonstrates basics of new
content stores.
diff --git a/utils/trie/freshness-policy.h b/utils/trie/freshness-policy.h
new file mode 100644
index 0000000..eec8400
--- /dev/null
+++ b/utils/trie/freshness-policy.h
@@ -0,0 +1,167 @@
+/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2012 University of California, Los Angeles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef FRESHNESS_POLICY_H_
+#define FRESHNESS_POLICY_H_
+
+#include <boost/intrusive/options.hpp>
+#include <boost/intrusive/list.hpp>
+
+#include <ns3/nstime.h>
+#include <ns3/simulator.h>
+#include <ns3/traced-callback.h>
+
+namespace ns3 {
+namespace ndn {
+namespace ndnSIM {
+
+/**
+ * @brief Traits for freshness policy
+ */
+struct freshness_policy_traits
+{
+ /// @brief Name that can be used to identify the policy (for NS-3 object model and logging)
+ static std::string GetName () { return "Freshness"; }
+
+ struct policy_hook_type : public boost::intrusive::set_member_hook<> { Time timeWhenShouldExpire; };
+
+ template<class Container>
+ struct container_hook
+ {
+ typedef boost::intrusive::member_hook< Container,
+ policy_hook_type,
+ &Container::policy_hook_ > type;
+ };
+
+ template<class Base,
+ class Container,
+ class Hook>
+ struct policy
+ {
+ static Time& get_freshness (typename Container::iterator item)
+ {
+ return static_cast<typename policy_container::value_traits::hook_type*>
+ (policy_container::value_traits::to_node_ptr(*item))->timeWhenShouldExpire;
+ }
+
+ static const Time& get_freshness (typename Container::const_iterator item)
+ {
+ return static_cast<const typename policy_container::value_traits::hook_type*>
+ (policy_container::value_traits::to_node_ptr(*item))->timeWhenShouldExpire;
+ }
+
+ template<class Key>
+ struct MemberHookLess
+ {
+ bool operator () (const Key &a, const Key &b) const
+ {
+ return get_freshness (&a) < get_freshness (&b);
+ }
+ };
+
+ typedef boost::intrusive::multiset< Container,
+ boost::intrusive::compare< MemberHookLess< Container > >,
+ Hook > policy_container;
+
+
+ class type : public policy_container
+ {
+ public:
+ typedef policy policy; // to get access to get_freshness methods from outside
+ typedef Container parent_trie;
+
+ type (Base &base)
+ : base_ (base)
+ , max_size_ (100)
+ {
+ }
+
+ inline void
+ update (typename parent_trie::iterator item)
+ {
+ // do nothing. it's random policy
+ }
+
+ inline bool
+ insert (typename parent_trie::iterator item)
+ {
+ // get_time (item) = Simulator::Now ();
+ Time freshness = item->payload ()->GetHeader ()->GetFreshness ();
+ if (!freshness.IsZero ())
+ {
+ get_freshness (item) = Simulator::Now () + freshness;
+
+ // push item only if freshness is non zero. otherwise, this payload is not controlled by the policy
+ // note that .size() on this policy would return only number of items with non-infinite freshness policy
+ policy_container::push_back (*item);
+ }
+
+ return true;
+ }
+
+ inline void
+ lookup (typename parent_trie::iterator item)
+ {
+ // do nothing. it's random policy
+ }
+
+ inline void
+ erase (typename parent_trie::iterator item)
+ {
+ if (!item->payload ()->GetHeader ()->GetFreshness ().IsZero ())
+ {
+ // erase only if freshness is non zero (otherwise an item is not in the policy
+ policy_container::erase (policy_container::s_iterator_to (*item));
+ }
+ }
+
+ inline void
+ clear ()
+ {
+ policy_container::clear ();
+ }
+
+ inline void
+ set_max_size (size_t max_size)
+ {
+ max_size_ = max_size;
+ }
+
+ inline size_t
+ get_max_size () const
+ {
+ return max_size_;
+ }
+
+ private:
+ type () : base_(*((Base*)0)) { };
+
+ private:
+ Base &base_;
+ size_t max_size_;
+ };
+ };
+};
+
+} // ndnSIM
+} // ndn
+} // ns3
+
+#endif // LIFETIME_STATS_POLICY_H