forked from cawka/ndn.cxx
diff --git a/ndn-cpp/trie/policies/counting-policy.h b/ndn-cpp/trie/policies/counting-policy.h
new file mode 100644
index 0000000..d27f915
--- /dev/null
+++ b/ndn-cpp/trie/policies/counting-policy.h
@@ -0,0 +1,101 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *                     Alexander Afanasyev
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef COUNTING_POLICY_H_
+#define COUNTING_POLICY_H_
+
+#include <boost/intrusive/options.hpp>
+#include <boost/intrusive/list.hpp>
+
+namespace ndn {
+namespace trie {
+
+/**
+ * @brief Traits for policy that just keeps track of number of elements
+ * It's doing a rather expensive job, but just in case it needs to be extended later
+ */
+struct counting_policy_traits
+{
+  /// @brief Name that can be used to identify the policy (e.g., for logging)
+  static std::string GetName () { return "Counting"; }
+
+  struct policy_hook_type : public boost::intrusive::list_member_hook<> {};
+
+  template<class Container>
+  struct container_hook
+  {
+    // could be class/struct implementation
+    typedef boost::intrusive::member_hook< Container,
+                             policy_hook_type,
+                             &Container::policy_hook_ > type;
+  };
+
+  template<class Base,
+           class Container,
+           class Hook>
+  struct policy 
+  {
+    typedef typename boost::intrusive::list< Container, Hook > policy_container;
+    
+    // could be just typedef
+    class type : public policy_container
+    {
+    public:
+      typedef Container parent_trie;
+
+      type (Base &base)
+        : base_ (base)
+      {
+      }
+
+      inline void
+      update (typename parent_trie::iterator item)
+      {
+        // do nothing
+      }
+  
+      inline bool
+      insert (typename parent_trie::iterator item)
+      {
+        policy_container::push_back (*item);
+        return true;
+      }
+  
+      inline void
+      lookup (typename parent_trie::iterator item)
+      {
+        // do nothing
+      }
+  
+      inline void
+      erase (typename parent_trie::iterator item)
+      {
+        policy_container::erase (policy_container::s_iterator_to (*item));
+      }
+
+      inline void
+      clear ()
+      {
+        policy_container::clear ();
+      }
+
+    private:
+      type () : base_(*((Base*)0)) { };
+
+    private:
+      Base &base_;
+    };
+  };
+};
+
+} // trie
+} // ndn
+
+#endif // COUNTING_POLICY_H_
diff --git a/ndn-cpp/trie/policies/empty-policy.h b/ndn-cpp/trie/policies/empty-policy.h
new file mode 100644
index 0000000..0cfe962
--- /dev/null
+++ b/ndn-cpp/trie/policies/empty-policy.h
@@ -0,0 +1,50 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *                     Alexander Afanasyev
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef EMPTY_POLICY_H_
+#define EMPTY_POLICY_H_
+
+namespace ndn {
+namespace trie {
+
+/**
+ * @brief Traits for empty (bogus) replacement policy
+ */
+struct empty_policy_traits
+{
+  /// @brief Name that can be used to identify the policy (e.g., for logging)
+  static std::string GetName () { return ""; }
+
+  typedef void* policy_hook_type;
+
+  template<class Container> struct container_hook { typedef void* type; };
+
+  template<class Base,
+           class Container,
+           class Hook>
+  struct policy 
+  {
+    struct type
+    {
+      inline type (Base &base) {}
+      
+      inline void update (typename Container::iterator) { }
+      inline bool insert (typename Container::iterator) { return true; }
+      inline void lookup (typename Container::iterator item) { }
+      inline void erase (typename Container::iterator item) { }
+      inline void clear () { }
+    };
+  };
+};
+
+} // trie
+} // ndn
+
+#endif // EMPTY_POLICY_H_
diff --git a/ndn-cpp/trie/policies/fifo-policy.h b/ndn-cpp/trie/policies/fifo-policy.h
new file mode 100644
index 0000000..7acad2b
--- /dev/null
+++ b/ndn-cpp/trie/policies/fifo-policy.h
@@ -0,0 +1,119 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *                     Alexander Afanasyev
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef FIFO_POLICY_H_
+#define FIFO_POLICY_H_
+
+#include <boost/intrusive/options.hpp>
+#include <boost/intrusive/list.hpp>
+
+namespace ndn {
+namespace trie {
+
+/**
+ * @brief Traits for First In First Out replacement policy
+ */
+struct fifo_policy_traits
+{
+  /// @brief Name that can be used to identify the policy (e.g., for logging)
+  static std::string GetName () { return "Fifo"; }
+
+  struct policy_hook_type : public boost::intrusive::list_member_hook<> {};
+
+  template<class Container>
+  struct container_hook
+  {
+    // could be class/struct implementation
+    typedef boost::intrusive::member_hook< Container,
+                             policy_hook_type,
+                             &Container::policy_hook_ > type;
+  };
+
+  template<class Base,
+           class Container,
+           class Hook>
+  struct policy 
+  {
+    typedef typename boost::intrusive::list< Container, Hook > policy_container;
+    
+    // could be just typedef
+    class type : public policy_container
+    {
+    public:
+      typedef Container parent_trie;
+
+      type (Base &base)
+        : base_ (base)
+        , max_size_ (100)
+      {
+      }
+
+      inline void
+      update (typename parent_trie::iterator item)
+      {
+        // do nothing
+      }
+  
+      inline bool
+      insert (typename parent_trie::iterator item)
+      {
+        if (max_size_ != 0 && policy_container::size () >= max_size_)
+          {
+            base_.erase (&(*policy_container::begin ()));
+          }
+      
+        policy_container::push_back (*item);
+        return true;
+      }
+  
+      inline void
+      lookup (typename parent_trie::iterator item)
+      {
+        // do nothing
+      }
+  
+      inline void
+      erase (typename parent_trie::iterator item)
+      {
+        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_;
+    };
+  };
+};
+
+} // trie
+} // ndn
+
+#endif
diff --git a/ndn-cpp/trie/policies/lfu-policy.h b/ndn-cpp/trie/policies/lfu-policy.h
new file mode 100644
index 0000000..802f64b
--- /dev/null
+++ b/ndn-cpp/trie/policies/lfu-policy.h
@@ -0,0 +1,149 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *                     Alexander Afanasyev
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef LFU_POLICY_H_
+#define LFU_POLICY_H_
+
+#include <boost/intrusive/options.hpp>
+#include <boost/intrusive/set.hpp>
+
+namespace ndn {
+namespace trie {
+
+/**
+ * @brief Traits for LFU replacement policy
+ */
+struct lfu_policy_traits
+{
+  /// @brief Name that can be used to identify the policy (e.g., for logging)
+  static std::string GetName () { return "Lfu"; }
+
+  struct policy_hook_type : public boost::intrusive::set_member_hook<> { double frequency; };
+
+  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 double& get_order (typename Container::iterator item)
+    {
+      return static_cast<policy_hook_type*>
+        (policy_container::value_traits::to_node_ptr(*item))->frequency;
+    }
+
+    static const double& get_order (typename Container::const_iterator item)
+    {
+      return static_cast<const policy_hook_type*>
+        (policy_container::value_traits::to_node_ptr(*item))->frequency;
+    }
+
+    template<class Key>
+    struct MemberHookLess
+    {
+      bool operator () (const Key &a, const Key &b) const
+      {
+        return get_order (&a) < get_order (&b);
+      }
+    };
+
+    typedef boost::intrusive::multiset< Container,
+                                   boost::intrusive::compare< MemberHookLess< Container > >,
+                                   Hook > policy_container;
+
+    // could be just typedef
+    class type : public policy_container
+    {
+    public:
+      typedef policy policy_base; // to get access to get_order methods from outside
+      typedef Container parent_trie;
+
+      type (Base &base)
+        : base_ (base)
+        , max_size_ (100)
+      {
+      }
+
+      inline void
+      update (typename parent_trie::iterator item)
+      {
+        policy_container::erase (policy_container::s_iterator_to (*item));
+        get_order (item) += 1;
+        policy_container::insert (*item);
+      }
+
+      inline bool
+      insert (typename parent_trie::iterator item)
+      {
+        get_order (item) = 0;
+
+        if (max_size_ != 0 && policy_container::size () >= max_size_)
+          {
+            // this erases the "least frequently used item" from cache
+            base_.erase (&(*policy_container::begin ()));
+          }
+
+        policy_container::insert (*item);
+        return true;
+      }
+
+      inline void
+      lookup (typename parent_trie::iterator item)
+      {
+        policy_container::erase (policy_container::s_iterator_to (*item));
+        get_order (item) += 1;
+        policy_container::insert (*item);
+      }
+
+      inline void
+      erase (typename parent_trie::iterator item)
+      {
+        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_;
+    };
+  };
+};
+
+} // trie
+} // ndn
+
+#endif // LFU_POLICY_H
diff --git a/ndn-cpp/trie/policies/lru-policy.h b/ndn-cpp/trie/policies/lru-policy.h
new file mode 100644
index 0000000..ad3a382
--- /dev/null
+++ b/ndn-cpp/trie/policies/lru-policy.h
@@ -0,0 +1,124 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *                     Alexander Afanasyev
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef LRU_POLICY_H_
+#define LRU_POLICY_H_
+
+#include <boost/intrusive/options.hpp>
+#include <boost/intrusive/list.hpp>
+
+namespace ndn {
+namespace trie {
+
+/**
+ * @brief Traits for Least Recently Used replacement policy
+ */
+struct lru_policy_traits
+{
+  /// @brief Name that can be used to identify the policy (e.g., for logging)
+  static std::string GetName () { return "Lru"; }
+  
+  struct policy_hook_type : public boost::intrusive::list_member_hook<> {};
+
+  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 
+  {
+    typedef typename boost::intrusive::list< Container, Hook > policy_container;
+    
+    // could be just typedef
+    class type : public policy_container
+    {
+    public:
+      typedef Container parent_trie;
+    
+      type (Base &base)
+        : base_ (base)
+        , max_size_ (100)
+      {
+      }
+
+      inline void
+      update (typename parent_trie::iterator item)
+      {
+        // do relocation
+        policy_container::splice (policy_container::end (),
+                                  *this,
+                                  policy_container::s_iterator_to (*item));
+      }
+  
+      inline bool
+      insert (typename parent_trie::iterator item)
+      {
+        if (max_size_ != 0 && policy_container::size () >= max_size_)
+          {
+            base_.erase (&(*policy_container::begin ()));
+          }
+      
+        policy_container::push_back (*item);
+        return true;
+      }
+  
+      inline void
+      lookup (typename parent_trie::iterator item)
+      {
+        // do relocation
+        policy_container::splice (policy_container::end (),
+                                  *this,
+                                  policy_container::s_iterator_to (*item));
+      }
+  
+      inline void
+      erase (typename parent_trie::iterator item)
+      {
+        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_;
+    };
+  };
+};
+
+} // trie
+} // ndn
+
+#endif
diff --git a/ndn-cpp/trie/policies/multi-policy.h b/ndn-cpp/trie/policies/multi-policy.h
new file mode 100644
index 0000000..739de7b
--- /dev/null
+++ b/ndn-cpp/trie/policies/multi-policy.h
@@ -0,0 +1,177 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *                     Alexander Afanasyev
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef MULTI_POLICY_H_
+#define MULTI_POLICY_H_
+
+#include "detail/multi-type-container.h"
+#include "detail/multi-policy-container.h"
+#include "detail/functor-hook.h"
+
+#include <boost/mpl/size.hpp>
+#include <boost/mpl/at.hpp>
+#include <boost/mpl/range_c.hpp>
+#include <boost/mpl/transform.hpp>
+#include <boost/mpl/back_inserter.hpp>
+#include <boost/mpl/vector.hpp>
+#include <boost/mpl/for_each.hpp>
+
+#include <boost/intrusive/options.hpp>
+
+namespace ndn {
+namespace trie {
+
+template<typename Policies> // e.g., mpl::vector1< lru_policy_traits >
+struct multi_policy_traits
+{
+  typedef Policies policy_traits;
+
+  struct getHook { template<class Item> struct apply { typedef typename Item::policy_hook_type type; }; };
+  typedef detail::multi_type_container< typename boost::mpl::transform1<policy_traits, getHook>::type > policy_hook_type;
+  
+  template<class Container>
+  struct container_hook
+  {
+    typedef policy_hook_type type;
+  };
+
+  template<class Base,
+           class Container,
+           class Hook>
+  struct policy 
+  {
+    typedef boost::mpl::range_c<int, 0, boost::mpl::size<policy_traits>::type::value> policies_range;
+
+    struct getPolicy
+    {
+      template<class Number>
+      struct apply
+      {
+        typedef
+        typename boost::mpl::at_c<policy_traits, Number::value>::type::
+        template policy<Base,
+                        Container,
+                        boost::intrusive::function_hook< detail::FunctorHook <Hook,
+                                                                              Container,
+                                                                              Number::value> > >::type
+        type;
+      };
+    };
+    
+    typedef
+    typename boost::mpl::transform1<policies_range,
+                                    getPolicy,
+                                    boost::mpl::back_inserter< boost::mpl::vector0<> > >::type policies;
+                             
+    
+    typedef detail::multi_policy_container< Base, policies > policy_container;
+    
+    class type : public policy_container
+    {
+    public:
+      typedef policy policy_base; // to get access to get_time methods from outside
+      typedef Container parent_trie;
+
+      type (Base &base)
+        : policy_container (base)
+      {
+      }
+
+      inline void
+      update (typename parent_trie::iterator item)
+      {
+        policy_container::update (item);
+      }
+  
+      inline bool
+      insert (typename parent_trie::iterator item)
+      {
+        return policy_container::insert (item);
+      }
+  
+      inline void
+      lookup (typename parent_trie::iterator item)
+      {
+        policy_container::lookup (item);
+      }
+  
+      inline void
+      erase (typename parent_trie::iterator item)
+      {
+        policy_container::erase (item);
+      }
+      
+      inline void
+      clear ()
+      {
+        policy_container::clear ();
+      }
+
+      struct max_size_setter
+      {
+        max_size_setter (policy_container &container, size_t size) : m_container (container), m_size (size) { }
+        
+        template< typename U > void operator() (U index)
+        {
+          m_container.template get<U::value> ().set_max_size (m_size);
+        }
+
+      private:
+        policy_container &m_container;
+        size_t m_size;
+      };
+      
+      inline void
+      set_max_size (size_t max_size)
+      {
+        boost::mpl::for_each< boost::mpl::range_c<int, 0, boost::mpl::size<policy_traits>::type::value> >
+          (max_size_setter (*this, max_size));
+      }
+
+      inline size_t
+      get_max_size () const
+      {
+        // as max size should be the same everywhere, get the value from the first available policy
+        return policy_container::template get<0> ().get_max_size ();
+      }
+      
+    };
+  };
+
+
+  struct name_getter
+  {
+    name_getter (std::string &name) : m_name (name) { }
+    
+    template< typename U > void operator() (U index)
+    {
+      if (!m_name.empty ())
+        m_name += "::";
+      m_name += boost::mpl::at_c< policy_traits, U::value >::type::GetName ();
+    }
+
+    std::string &m_name;
+  };
+
+  /// @brief Name that can be used to identify the policy (e.g., for logging)
+  static std::string GetName ()
+  {
+    // combine names of all internal policies
+    std::string name;
+    boost::mpl::for_each< boost::mpl::range_c<int, 0, boost::mpl::size<policy_traits>::type::value> > (name_getter (name));
+    
+    return name;
+  }
+};
+
+} // trie
+} // ndn
+
+#endif // MULTI_POLICY_H_
diff --git a/ndn-cpp/trie/policies/persistent-policy.h b/ndn-cpp/trie/policies/persistent-policy.h
new file mode 100644
index 0000000..d34f373
--- /dev/null
+++ b/ndn-cpp/trie/policies/persistent-policy.h
@@ -0,0 +1,119 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *                     Alexander Afanasyev
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef PERSISTENT_POLICY_H_
+#define PERSISTENT_POLICY_H_
+
+#include <boost/intrusive/options.hpp>
+#include <boost/intrusive/list.hpp>
+
+namespace ndn {
+namespace trie {
+
+/**
+ * @brief Traits for persistent replacement policy
+ *
+ * In this policy entries are added until there is a space (controlled by set_max_size call).
+ * If maximum is reached, new entries will not be added and nothing will be removed from the container
+ */
+struct persistent_policy_traits
+{
+  /// @brief Name that can be used to identify the policy (e.g., for logging)
+  static std::string GetName () { return "Persistent"; }
+
+  struct policy_hook_type : public boost::intrusive::list_member_hook<> {};
+
+  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 
+  {
+    typedef typename boost::intrusive::list< Container, Hook > policy_container;
+    
+    // could be just typedef
+    class type : public policy_container
+    {
+    public:
+      typedef Container parent_trie;
+    
+      type (Base &base)
+        : base_ (base)
+        , max_size_ (100) // when 0, policy is not enforced
+      {
+      }
+
+      inline void
+      update (typename parent_trie::iterator item)
+      {
+        // do nothing
+      }
+  
+      inline bool
+      insert (typename parent_trie::iterator item)
+      {
+        if (max_size_ != 0 && policy_container::size () >= max_size_)
+          return false;
+      
+        policy_container::push_back (*item);
+        return true;
+      }
+  
+      inline void
+      lookup (typename parent_trie::iterator item)
+      {
+        // do nothing
+      }
+  
+      inline void
+      erase (typename parent_trie::iterator item)
+      {
+        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_;
+    };
+  };
+};
+
+} // trie
+} // ndn
+
+#endif // PERSISTENT_POLICY_H_
diff --git a/ndn-cpp/trie/policies/random-policy.h b/ndn-cpp/trie/policies/random-policy.h
new file mode 100644
index 0000000..d896e89
--- /dev/null
+++ b/ndn-cpp/trie/policies/random-policy.h
@@ -0,0 +1,158 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *                     Alexander Afanasyev
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef RANDOM_POLICY_H_
+#define RANDOM_POLICY_H_
+
+#include "ns3/random-variable.h"
+
+#include <boost/intrusive/options.hpp>
+#include <boost/intrusive/set.hpp>
+
+namespace ndn {
+namespace trie {
+
+/**
+ * @brief Traits for random replacement policy
+ */
+struct random_policy_traits
+{
+  /// @brief Name that can be used to identify the policy (e.g., for logging)
+  static std::string GetName () { return "Random"; }
+
+  struct policy_hook_type : public boost::intrusive::set_member_hook<> { uint32_t randomOrder; };
+
+  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 uint32_t& get_order (typename Container::iterator item)
+    {
+      return static_cast<typename policy_container::value_traits::hook_type*>
+        (policy_container::value_traits::to_node_ptr(*item))->randomOrder;
+    }
+      
+    static const uint32_t& get_order (typename Container::const_iterator item)
+    {
+      return static_cast<const typename policy_container::value_traits::hook_type*>
+        (policy_container::value_traits::to_node_ptr(*item))->randomOrder;
+    }
+    
+    template<class Key>
+    struct MemberHookLess
+    {
+      bool operator () (const Key &a, const Key &b) const
+      {
+        return get_order (&a) < get_order (&b);
+      }
+    };
+
+    typedef boost::intrusive::multiset< Container,
+                                   boost::intrusive::compare< MemberHookLess< Container > >,
+                                   Hook > policy_container;
+    
+    // could be just typedef
+    class type : public policy_container
+    {
+    public:
+      typedef policy policy_base; // to get access to get_order methods from outside
+      typedef Container parent_trie;
+
+      type (Base &base)
+        : base_ (base)
+        , u_rand (0, std::numeric_limits<uint32_t>::max ())
+        , 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_order (item) = u_rand.GetValue ();
+
+        if (max_size_ != 0 && policy_container::size () >= max_size_)
+          {
+            if (MemberHookLess<Container>() (*item, *policy_container::begin ()))
+              {
+                // std::cout << "Cannot add. Signaling fail\n";
+                // just return false. Indicating that insert "failed"
+                return false;
+              }
+            else
+              {
+                // removing some random element
+                base_.erase (&(*policy_container::begin ()));
+              }
+          }
+
+        policy_container::insert (*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)
+      {
+        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_;
+      ns3::UniformVariable u_rand;
+      size_t max_size_;
+    };
+  };
+};
+
+} // trie
+} // ndn
+
+#endif // RANDOM_POLICY_H