Edit File: resize_policy.hpp
// -*- C++ -*- // Copyright (C) 2005-2018 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 binary_heap_/resize_policy.hpp * Contains an implementation class for a binary_heap. */ #ifndef PB_DS_BINARY_HEAP_RESIZE_POLICY_HPP #define PB_DS_BINARY_HEAP_RESIZE_POLICY_HPP #include <debug/debug.h> namespace __gnu_pbds { namespace detail { /// Resize policy for binary heap. template<typename _Tp> class resize_policy { private: enum { ratio = 8, factor = 2 }; /// Next shrink size. _Tp m_shrink_size; /// Next grow size. _Tp m_grow_size; public: typedef _Tp size_type; static const _Tp min_size = 16; resize_policy() : m_shrink_size(0), m_grow_size(min_size) { PB_DS_ASSERT_VALID((*this)) } resize_policy(const resize_policy& other) : m_shrink_size(other.m_shrink_size), m_grow_size(other.m_grow_size) { PB_DS_ASSERT_VALID((*this)) } inline void swap(resize_policy<_Tp>&); inline bool resize_needed_for_grow(size_type) const; inline bool resize_needed_for_shrink(size_type) const; inline bool grow_needed(size_type) const; inline bool shrink_needed(size_type) const; inline size_type get_new_size_for_grow() const; inline size_type get_new_size_for_shrink() const; inline size_type get_new_size_for_arbitrary(size_type) const; inline void notify_grow_resize(); inline void notify_shrink_resize(); void notify_arbitrary(size_type); #ifdef _GLIBCXX_DEBUG void assert_valid(const char*, int) const; #endif #ifdef PB_DS_BINARY_HEAP_TRACE_ void trace() const; #endif }; template<typename _Tp> const _Tp resize_policy<_Tp>::min_size; template<typename _Tp> inline void resize_policy<_Tp>:: swap(resize_policy<_Tp>& other) { std::swap(m_shrink_size, other.m_shrink_size); std::swap(m_grow_size, other.m_grow_size); } template<typename _Tp> inline bool resize_policy<_Tp>:: resize_needed_for_grow(size_type size) const { _GLIBCXX_DEBUG_ASSERT(size <= m_grow_size); return size == m_grow_size; } template<typename _Tp> inline bool resize_policy<_Tp>:: resize_needed_for_shrink(size_type size) const { _GLIBCXX_DEBUG_ASSERT(size <= m_grow_size); return size == m_shrink_size; } template<typename _Tp> inline typename resize_policy<_Tp>::size_type resize_policy<_Tp>:: get_new_size_for_grow() const { return m_grow_size * factor; } template<typename _Tp> inline typename resize_policy<_Tp>::size_type resize_policy<_Tp>:: get_new_size_for_shrink() const { const size_type half_size = m_grow_size / factor; return std::max(min_size, half_size); } template<typename _Tp> inline typename resize_policy<_Tp>::size_type resize_policy<_Tp>:: get_new_size_for_arbitrary(size_type size) const { size_type ret = min_size; while (ret < size) ret *= factor; return ret; } template<typename _Tp> inline void resize_policy<_Tp>:: notify_grow_resize() { PB_DS_ASSERT_VALID((*this)) _GLIBCXX_DEBUG_ASSERT(m_grow_size >= min_size); m_grow_size *= factor; m_shrink_size = m_grow_size / ratio; PB_DS_ASSERT_VALID((*this)) } template<typename _Tp> inline void resize_policy<_Tp>:: notify_shrink_resize() { PB_DS_ASSERT_VALID((*this)) m_shrink_size /= factor; if (m_shrink_size == 1) m_shrink_size = 0; m_grow_size = std::max(m_grow_size / factor, min_size); PB_DS_ASSERT_VALID((*this)) } template<typename _Tp> inline void resize_policy<_Tp>:: notify_arbitrary(size_type actual_size) { m_grow_size = actual_size; m_shrink_size = m_grow_size / ratio; PB_DS_ASSERT_VALID((*this)) } #ifdef _GLIBCXX_DEBUG template<typename _Tp> void resize_policy<_Tp>:: assert_valid(const char* __file, int __line) const { PB_DS_DEBUG_VERIFY(m_shrink_size == 0 || m_shrink_size * ratio == m_grow_size); PB_DS_DEBUG_VERIFY(m_grow_size >= min_size); } #endif #ifdef PB_DS_BINARY_HEAP_TRACE_ template<typename _Tp> void resize_policy<_Tp>:: trace() const { std::cerr << "shrink = " << m_shrink_size << " grow = " << m_grow_size << std::endl; } #endif } // namespace detail } // namespace __gnu_pbds #endif
Back to File Manager