forked from KolibriOS/kolibrios
131 lines
4.3 KiB
C++
131 lines
4.3 KiB
C++
|
// -*- C++ -*-
|
||
|
|
||
|
// Copyright (C) 2005-2015 Free Software Foundation, Inc.
|
||
|
//
|
||
|
// This file is part of the GNU ISO C++ Library. This library 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, or (at your option) any later
|
||
|
// version.
|
||
|
|
||
|
// This library 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.
|
||
|
|
||
|
// Under Section 7 of GPL version 3, you are granted additional
|
||
|
// permissions described in the GCC Runtime Library Exception, version
|
||
|
// 3.1, as published by the Free Software Foundation.
|
||
|
|
||
|
// You should have received a copy of the GNU General Public License and
|
||
|
// a copy of the GCC Runtime Library Exception along with this program;
|
||
|
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
||
|
// <http://www.gnu.org/licenses/>.
|
||
|
|
||
|
// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
|
||
|
|
||
|
// Permission to use, copy, modify, sell, and distribute this software
|
||
|
// is hereby granted without fee, provided that the above copyright
|
||
|
// notice appears in all copies, and that both that copyright notice
|
||
|
// and this permission notice appear in supporting documentation. None
|
||
|
// of the above authors, nor IBM Haifa Research Laboratories, make any
|
||
|
// representation about the suitability of this software for any
|
||
|
// purpose. It is provided "as is" without express or implied
|
||
|
// warranty.
|
||
|
|
||
|
/**
|
||
|
* @file list_update_policy.hpp
|
||
|
* Contains policies for list update containers.
|
||
|
*/
|
||
|
|
||
|
#ifndef PB_DS_LU_POLICY_HPP
|
||
|
#define PB_DS_LU_POLICY_HPP
|
||
|
|
||
|
#include <bits/c++config.h>
|
||
|
#include <cstdlib>
|
||
|
#include <ext/pb_ds/detail/list_update_policy/lu_counter_metadata.hpp>
|
||
|
#include <ext/pb_ds/tag_and_trait.hpp>
|
||
|
|
||
|
namespace __gnu_pbds
|
||
|
{
|
||
|
/**
|
||
|
* A list-update policy that unconditionally moves elements to the
|
||
|
* front of the list. A null type means that each link in a
|
||
|
* list-based container does not actually need metadata.
|
||
|
*/
|
||
|
template<typename _Alloc = std::allocator<char> >
|
||
|
class lu_move_to_front_policy
|
||
|
{
|
||
|
public:
|
||
|
typedef _Alloc allocator_type;
|
||
|
|
||
|
/// Metadata on which this functor operates.
|
||
|
typedef null_type metadata_type;
|
||
|
|
||
|
private:
|
||
|
typedef typename _Alloc::template rebind<metadata_type> __rebind_m;
|
||
|
|
||
|
public:
|
||
|
/// Reference to metadata on which this functor operates.
|
||
|
typedef typename __rebind_m::other::reference metadata_reference;
|
||
|
|
||
|
/// Creates a metadata object.
|
||
|
metadata_type
|
||
|
operator()() const
|
||
|
{ return s_metadata; }
|
||
|
|
||
|
/// Decides whether a metadata object should be moved to the front
|
||
|
/// of the list.
|
||
|
inline bool
|
||
|
operator()(metadata_reference r_metadata) const
|
||
|
{ return true; }
|
||
|
|
||
|
private:
|
||
|
static null_type s_metadata;
|
||
|
};
|
||
|
|
||
|
/**
|
||
|
* A list-update policy that moves elements to the front of the
|
||
|
* list based on the counter algorithm.
|
||
|
*/
|
||
|
template<std::size_t Max_Count = 5, typename _Alloc = std::allocator<char> >
|
||
|
class lu_counter_policy
|
||
|
: private detail::lu_counter_policy_base<typename _Alloc::size_type>
|
||
|
{
|
||
|
public:
|
||
|
typedef _Alloc allocator_type;
|
||
|
typedef typename allocator_type::size_type size_type;
|
||
|
|
||
|
enum
|
||
|
{
|
||
|
/// When some element is accessed this number of times, it
|
||
|
/// will be moved to the front of the list.
|
||
|
max_count = Max_Count
|
||
|
};
|
||
|
|
||
|
/// Metadata on which this functor operates.
|
||
|
typedef detail::lu_counter_metadata<size_type> metadata_type;
|
||
|
|
||
|
private:
|
||
|
typedef detail::lu_counter_policy_base<size_type> base_type;
|
||
|
typedef typename _Alloc::template rebind<metadata_type> __rebind_m;
|
||
|
|
||
|
public:
|
||
|
/// Reference to metadata on which this functor operates.
|
||
|
typedef typename __rebind_m::other::reference metadata_reference;
|
||
|
|
||
|
/// Creates a metadata object.
|
||
|
metadata_type
|
||
|
operator()() const
|
||
|
{ return base_type::operator()(max_count); }
|
||
|
|
||
|
/// Decides whether a metadata object should be moved to the front
|
||
|
/// of the list.
|
||
|
bool
|
||
|
operator()(metadata_reference r_data) const
|
||
|
{ return base_type::operator()(r_data, max_count); }
|
||
|
};
|
||
|
} // namespace __gnu_pbds
|
||
|
|
||
|
#endif
|