forked from cawka/ndn.cxx
diff --git a/ndn-cpp/trie/policies/multi-policy.h b/ndn-cpp/trie/policies/multi-policy.h
new file mode 100644
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+++ 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_