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/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2011 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 SERIALIZED_POLICY_H_
#define SERIALIZED_POLICY_H_
#include <boost/intrusive/options.hpp>
#include <boost/intrusive/set.hpp>
namespace ns3 {
namespace ndn {
namespace ndnSIM {
/**
* @brief Traits for Least Recently Used replacement policy
*/
struct serialized_size_policy_traits
{
/// @brief Name that can be used to identify the policy (for NS-3 object model and logging)
static std::string GetName () { return "SerializedSize"; }
struct policy_hook_type : public boost::intrusive::set_member_hook<> { uint32_t size; };
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_size (typename Container::iterator item)
{
return static_cast<typename policy_container::value_traits::hook_type*>
(policy_container::value_traits::to_node_ptr(*item))->size;
}
static const uint32_t& get_size (typename Container::const_iterator item)
{
return static_cast<const typename policy_container::value_traits::hook_type*>
(policy_container::value_traits::to_node_ptr(*item))->size;
}
template<class Key>
struct MemberHookLess
{
bool operator () (const Key &a, const Key &b) const
{
return get_size (&a) < get_size (&b);
}
};
typedef typename boost::intrusive::multiset< Container,
boost::intrusive::compare< MemberHookLess< 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_ (10000) // size in bytes. Default ~10 kilobytes
, current_space_used_ (0)
{
}
inline void
update (typename parent_trie::iterator item)
{
// in case size got changed
current_space_used_ -= get_size (item);
policy_container::erase (*item);
if (item->payload ()->GetInterest ()->GetWire ())
{
policy::get_size (item) = item->payload ()->GetInterest ()->GetWire ()->GetSize ();
}
else
{
policy::get_size (item) = 0;
}
current_space_used_ += get_size (item); // this operation can violate policy constraint, so in some case
// it may be necessary to remove some other element
policy_container::insert (*item);
}
inline bool
insert (typename parent_trie::iterator item)
{
uint32_t interestSize = 0;
if (item->payload ()->GetInterest ()->GetWire ())
{
interestSize = item->payload ()->GetInterest ()->GetWire ()->GetSize ();
}
// can't use logging here
NS_LOG_DEBUG ("Number of entries: " << policy_container::size ()
<< ", space used: " << current_space_used_
<< ", name: " << item->payload ()->GetPrefix ()
<< ", interest size: " << interestSize);
if (max_size_ != 0 && current_space_used_ + interestSize > max_size_)
{
NS_LOG_DEBUG ("Rejecting PIT entry");
// the current version just fails to add an element, but it also possible
// to remove the largest element (last element in multi_map policy container)
return false;
}
policy::get_size (item) = interestSize;
current_space_used_ += interestSize;
policy_container::insert (*item);
return true;
}
inline void
lookup (typename parent_trie::iterator item)
{
// do nothing
}
inline void
erase (typename parent_trie::iterator item)
{
NS_LOG_DEBUG ("Erasing entry with name: " << item->payload ()->GetPrefix ());
current_space_used_ -= policy::get_size (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_;
}
inline uint32_t
get_current_space_used () const
{
return current_space_used_;
}
private:
type () : base_(*((Base*)0)) { };
private:
Base &base_;
uint32_t max_size_;
uint32_t current_space_used_;
};
};
};
} // ndnSIM
} // ndn
} // ns3
#endif