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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
* Copyright (c) 2011-2015 Regents of the University of California.
*
* This file is part of ndnSIM. See AUTHORS for complete list of ndnSIM authors and
* contributors.
*
* ndnSIM is free software: you can redistribute it and/or modify it under the terms
* of the GNU General Public License as published by the Free Software Foundation,
* either version 3 of the License, or (at your option) any later version.
*
* ndnSIM 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
* ndnSIM, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
**/
#ifndef RANDOM_POLICY_H_
#define RANDOM_POLICY_H_
/// @cond include_hidden
#include "ns3/random-variable-stream.h"
#include "ns3/double.h"
#include <boost/intrusive/options.hpp>
#include <boost/intrusive/set.hpp>
namespace ns3 {
namespace ndn {
namespace ndnSIM {
/**
* @brief Traits for random replacement policy
*/
struct random_policy_traits {
/// @brief Name that can be used to identify the policy (for NS-3 object model and 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(CreateObject<UniformRandomVariable>())
, max_size_(100)
{
u_rand->SetAttribute("Min", DoubleValue(0));
u_rand->SetAttribute("Max", DoubleValue(std::numeric_limits<uint32_t>::max()));
}
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_;
Ptr<UniformRandomVariable> u_rand;
size_t max_size_;
};
};
};
} // ndnSIM
} // ndn
} // ns3
/// @endcond
#endif // RANDOM_POLICY_H