3 // Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the terms
7 // of the GNU General Public License as published by the Free Software
8 // Foundation; either version 3, or (at your option) any later
11 // This library is distributed in the hope that it will be useful, but
12 // WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 // General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
27 // Permission to use, copy, modify, sell, and distribute this software
28 // is hereby granted without fee, provided that the above copyright
29 // notice appears in all copies, and that both that copyright notice
30 // and this permission notice appear in supporting documentation. None
31 // of the above authors, nor IBM Haifa Research Laboratories, make any
32 // representation about the suitability of this software for any
33 // purpose. It is provided "as is" without express or implied
37 * @file resize_policy.hpp
38 * Contains an implementation class for a binary_heap.
41 #ifndef PB_DS_BINARY_HEAP_RESIZE_POLICY_HPP
42 #define PB_DS_BINARY_HEAP_RESIZE_POLICY_HPP
44 #include <debug/debug.h>
51 #define PB_DS_CLASS_T_DEC template<typename Size_Type>
53 #define PB_DS_CLASS_C_DEC resize_policy<Size_Type>
55 template<typename Size_Type>
59 typedef Size_Type size_type;
71 swap(PB_DS_CLASS_C_DEC& other);
74 resize_needed_for_grow(size_type size) const;
77 resize_needed_for_shrink(size_type size) const;
80 grow_needed(size_type size) const;
83 shrink_needed(size_type size) const;
86 get_new_size_for_grow() const;
89 get_new_size_for_shrink() const;
92 get_new_size_for_arbitrary(size_type size) const;
98 notify_shrink_resize();
101 notify_arbitrary(size_type actual_size);
103 #ifdef _GLIBCXX_DEBUG
105 assert_valid() const;
108 #ifdef PB_DS_BINARY_HEAP_TRACE_
121 size_type m_next_shrink_size;
122 size_type m_next_grow_size;
129 m_next_shrink_size(0),
130 m_next_grow_size(min_size)
131 { _GLIBCXX_DEBUG_ONLY(assert_valid();) }
136 swap(PB_DS_CLASS_C_DEC& other)
138 std::swap(m_next_shrink_size, other.m_next_shrink_size);
139 std::swap(m_next_grow_size, other.m_next_grow_size);
145 resize_needed_for_grow(size_type size) const
147 _GLIBCXX_DEBUG_ASSERT(size <= m_next_grow_size);
148 return size == m_next_grow_size;
154 resize_needed_for_shrink(size_type size) const
156 _GLIBCXX_DEBUG_ASSERT(size <= m_next_grow_size);
157 return size == m_next_shrink_size;
161 inline typename PB_DS_CLASS_C_DEC::size_type
163 get_new_size_for_grow() const
164 { return m_next_grow_size* factor; }
167 inline typename PB_DS_CLASS_C_DEC::size_type
169 get_new_size_for_shrink() const
171 const size_type half_size = m_next_grow_size / factor;
172 return std::max(static_cast<size_type>(min_size), half_size);
176 inline typename PB_DS_CLASS_C_DEC::size_type
178 get_new_size_for_arbitrary(size_type size) const
180 size_type ret = min_size;
191 _GLIBCXX_DEBUG_ONLY(assert_valid();)
192 _GLIBCXX_DEBUG_ASSERT(m_next_grow_size >= min_size);
193 m_next_grow_size *= factor;
194 m_next_shrink_size = m_next_grow_size / ratio;
195 _GLIBCXX_DEBUG_ONLY(assert_valid();)
201 notify_shrink_resize()
203 _GLIBCXX_DEBUG_ONLY(assert_valid();)
204 m_next_shrink_size /= factor;
205 if (m_next_shrink_size == 1)
206 m_next_shrink_size = 0;
209 std::max(m_next_grow_size / factor, static_cast<size_type>(min_size));
210 _GLIBCXX_DEBUG_ONLY(assert_valid();)
216 notify_arbitrary(size_type actual_size)
218 m_next_grow_size = actual_size;
219 m_next_shrink_size = m_next_grow_size / ratio;
220 _GLIBCXX_DEBUG_ONLY(assert_valid();)
223 #ifdef _GLIBCXX_DEBUG
229 _GLIBCXX_DEBUG_ASSERT(m_next_shrink_size == 0 ||
230 m_next_shrink_size* ratio == m_next_grow_size);
232 _GLIBCXX_DEBUG_ASSERT(m_next_grow_size >= min_size);
236 #ifdef PB_DS_BINARY_HEAP_TRACE_
242 std::cerr << "shrink = " << m_next_shrink_size <<
243 " grow = " << m_next_grow_size << std::endl;
247 #undef PB_DS_CLASS_T_DEC
248 #undef PB_DS_CLASS_C_DEC
250 } // namespace detail
251 } // namespace __gnu_pbds