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/model/cs/content-store-with-freshness.h b/model/cs/content-store-with-freshness.h
new file mode 100644
index 0000000..c15ded6
--- /dev/null
+++ b/model/cs/content-store-with-freshness.h
@@ -0,0 +1,164 @@
+/* -*- 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 NDN_CONTENT_STORE_WITH_FRESHNESS_H_
+#define NDN_CONTENT_STORE_WITH_FRESHNESS_H_
+
+#include "content-store-impl.h"
+
+#include "../../utils/trie/multi-policy.h"
+#include "../../utils/trie/freshness-policy.h"
+
+namespace ns3 {
+namespace ndn {
+namespace cs {
+
+template<class Policy>
+class ContentStoreWithFreshness :
+ public ContentStoreImpl< ndnSIM::multi_policy_traits< boost::mpl::vector2< Policy, ndnSIM::freshness_policy_traits > > >
+{
+public:
+ typedef ContentStoreImpl< ndnSIM::multi_policy_traits< boost::mpl::vector2< Policy, ndnSIM::freshness_policy_traits > > > super;
+
+ typedef typename super::policy_container::template index<1>::type freshness_policy_container;
+
+ static TypeId
+ GetTypeId ();
+
+ virtual inline bool
+ Add (Ptr<const ContentObjectHeader> header, Ptr<const Packet> packet);
+
+private:
+ inline void
+ CleanExpired ();
+
+ inline void
+ RescheduleCleaning ();
+
+private:
+ static LogComponent g_log; ///< @brief Logging variable
+
+ EventId m_cleanEvent;
+ Time m_scheduledCleaningTime;
+};
+
+//////////////////////////////////////////
+////////// Implementation ////////////////
+//////////////////////////////////////////
+
+
+template<class Policy>
+LogComponent
+ContentStoreWithFreshness< Policy >::g_log = LogComponent (("ndn.cs.Freshness." + Policy::GetName ()).c_str ());
+
+
+template<class Policy>
+TypeId
+ContentStoreWithFreshness< Policy >::GetTypeId ()
+{
+ static TypeId tid = TypeId (("ns3::ndn::cs::Freshness::"+Policy::GetName ()).c_str ())
+ .SetGroupName ("Ndn")
+ .SetParent<super> ()
+ .template AddConstructor< ContentStoreWithFreshness< Policy > > ()
+
+ // trace stuff here
+ ;
+
+ return tid;
+}
+
+
+template<class Policy>
+inline bool
+ContentStoreWithFreshness< Policy >::Add (Ptr<const ContentObjectHeader> header, Ptr<const Packet> packet)
+{
+ bool ok = super::Add (header, packet);
+ if (!ok) return false;
+
+ NS_LOG_DEBUG (header->GetName () << " added to cache");
+ RescheduleCleaning ();
+ return true;
+}
+
+template<class Policy>
+inline void
+ContentStoreWithFreshness< Policy >::RescheduleCleaning ()
+{
+ const freshness_policy_container &freshness = this->getPolicy ().template get<freshness_policy_container> ();
+
+ if (freshness.size () > 0)
+ {
+ Time nextStateTime = freshness_policy_container::policy::get_freshness (&(*freshness.begin ()));
+
+ if (m_scheduledCleaningTime.IsZero () || // if not yet scheduled
+ m_scheduledCleaningTime > nextStateTime) // if new item expire sooner than already scheduled
+ {
+ if (m_cleanEvent.IsRunning ())
+ {
+ Simulator::Remove (m_cleanEvent); // just canceling would not clean up list of events
+ }
+
+ // NS_LOG_DEBUG ("Next event in: " << (nextStateTime - Now ()).ToDouble (Time::S) << "s");
+ m_cleanEvent = Simulator::Schedule (nextStateTime - Now (), &ContentStoreWithFreshness< Policy >::CleanExpired, this);
+ m_scheduledCleaningTime = nextStateTime;
+ }
+ }
+ else
+ {
+ if (m_cleanEvent.IsRunning ())
+ {
+ Simulator::Remove (m_cleanEvent); // just canceling would not clean up list of events
+ }
+ }
+}
+
+
+template<class Policy>
+inline void
+ContentStoreWithFreshness< Policy >::CleanExpired ()
+{
+ freshness_policy_container &freshness = this->getPolicy ().template get<freshness_policy_container> ();
+
+ // NS_LOG_LOGIC (">> Cleaning: Total number of items:" << this->getPolicy ().size () << ", items with freshness: " << freshness.size ());
+ Time now = Simulator::Now ();
+
+ while (!freshness.empty ())
+ {
+ typename freshness_policy_container::iterator entry = freshness.begin ();
+
+ if (freshness_policy_container::policy::get_freshness (&(*entry)) <= now) // is the record stale?
+ {
+ super::erase (&(*entry));
+ }
+ else
+ break; // nothing else to do. All later records will not be stale
+ }
+ // NS_LOG_LOGIC ("<< Cleaning: Total number of items:" << this->getPolicy ().size () << ", items with freshness: " << freshness.size ());
+
+ m_scheduledCleaningTime = Time ();
+ RescheduleCleaning ();
+}
+
+
+} // namespace cs
+} // namespace ndn
+} // namespace ns3
+
+#endif // NDN_CONTENT_STORE_WITH_FRESHNESS_H_