hash_load_check_resize_trigger_imp.hpp revision 1.1.1.1 
1// -*- C++ -*-
2
3// Copyright (C) 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4//
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
9// version.
10
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.
15
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.
19
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/>.
24
25// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
26
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
34// warranty.
35
36/**
37 * @file hash_load_check_resize_trigger_imp.hpp
38 * Contains a resize trigger implementation.
39 */
40
41PB_DS_CLASS_T_DEC
42PB_DS_CLASS_C_DEC::
43hash_load_check_resize_trigger(float load_min, float load_max)
44: m_load_min(load_min), m_load_max(load_max), m_next_shrink_size(0),
45  m_next_grow_size(0), m_resize_needed(false)
46{ _GLIBCXX_DEBUG_ONLY(assert_valid();) }
47
48PB_DS_CLASS_T_DEC
49inline void
50PB_DS_CLASS_C_DEC::
51notify_find_search_start()
52{ _GLIBCXX_DEBUG_ONLY(assert_valid();) }
53
54PB_DS_CLASS_T_DEC
55inline void
56PB_DS_CLASS_C_DEC::
57notify_find_search_collision()
58{ _GLIBCXX_DEBUG_ONLY(assert_valid();) }
59
60PB_DS_CLASS_T_DEC
61inline void
62PB_DS_CLASS_C_DEC::
63notify_find_search_end()
64{ _GLIBCXX_DEBUG_ONLY(assert_valid();) }
65
66PB_DS_CLASS_T_DEC
67inline void
68PB_DS_CLASS_C_DEC::
69notify_insert_search_start()
70{ _GLIBCXX_DEBUG_ONLY(assert_valid();) }
71
72PB_DS_CLASS_T_DEC
73inline void
74PB_DS_CLASS_C_DEC::
75notify_insert_search_collision()
76{ _GLIBCXX_DEBUG_ONLY(assert_valid();) }
77
78PB_DS_CLASS_T_DEC
79inline void
80PB_DS_CLASS_C_DEC::
81notify_insert_search_end()
82{ _GLIBCXX_DEBUG_ONLY(assert_valid();) }
83
84PB_DS_CLASS_T_DEC
85inline void
86PB_DS_CLASS_C_DEC::
87notify_erase_search_start()
88{ _GLIBCXX_DEBUG_ONLY(assert_valid();) }
89
90PB_DS_CLASS_T_DEC
91inline void
92PB_DS_CLASS_C_DEC::
93notify_erase_search_collision()
94{ _GLIBCXX_DEBUG_ONLY(assert_valid();) }
95
96PB_DS_CLASS_T_DEC
97inline void
98PB_DS_CLASS_C_DEC::
99notify_erase_search_end()
100{ _GLIBCXX_DEBUG_ONLY(assert_valid();) }
101
102PB_DS_CLASS_T_DEC
103inline void
104PB_DS_CLASS_C_DEC::
105notify_inserted(size_type num_entries)
106{
107  m_resize_needed = (num_entries >= m_next_grow_size);
108  size_base::set_size(num_entries);
109  _GLIBCXX_DEBUG_ONLY(assert_valid();)
110}
111
112PB_DS_CLASS_T_DEC
113inline void
114PB_DS_CLASS_C_DEC::
115notify_erased(size_type num_entries)
116{
117  size_base::set_size(num_entries);
118  m_resize_needed = num_entries <= m_next_shrink_size;
119  _GLIBCXX_DEBUG_ONLY(assert_valid();)
120}
121
122PB_DS_CLASS_T_DEC
123inline bool
124PB_DS_CLASS_C_DEC::
125is_resize_needed() const
126{
127  _GLIBCXX_DEBUG_ONLY(assert_valid();)
128  return m_resize_needed;
129}
130
131PB_DS_CLASS_T_DEC
132inline bool
133PB_DS_CLASS_C_DEC::
134is_grow_needed(size_type /*size*/, size_type num_entries) const
135{
136  _GLIBCXX_DEBUG_ASSERT(m_resize_needed);
137  return num_entries >= m_next_grow_size;
138}
139
140PB_DS_CLASS_T_DEC
141PB_DS_CLASS_C_DEC::
142~hash_load_check_resize_trigger() { }
143
144PB_DS_CLASS_T_DEC
145void
146PB_DS_CLASS_C_DEC::
147notify_resized(size_type new_size)
148{
149  m_resize_needed = false;
150  m_next_grow_size = size_type(m_load_max * new_size - 1);
151  m_next_shrink_size = size_type(m_load_min * new_size);
152
153#ifdef PB_DS_HT_MAP_RESIZE_TRACE_
154  std::cerr << "hlcrt::notify_resized " <<
155    static_cast<unsigned long>(new_size) << "    " <<
156    static_cast<unsigned long>(m_load_min) << "    " <<
157    static_cast<unsigned long>(m_load_max) << "    " <<
158    static_cast<unsigned long>(m_next_shrink_size) << " " <<
159    static_cast<unsigned long>(m_next_grow_size) << "    " << std::endl;
160#endif
161
162  _GLIBCXX_DEBUG_ONLY(assert_valid();)
163}
164
165PB_DS_CLASS_T_DEC
166void
167PB_DS_CLASS_C_DEC::
168notify_externally_resized(size_type new_size)
169{
170  m_resize_needed = false;
171  size_type new_grow_size = size_type(m_load_max * new_size - 1);
172  size_type new_shrink_size = size_type(m_load_min * new_size);
173  if (new_grow_size >= m_next_grow_size)
174    {
175      _GLIBCXX_DEBUG_ASSERT(new_shrink_size > m_next_shrink_size);
176      m_next_grow_size = new_grow_size;
177      _GLIBCXX_DEBUG_ONLY(assert_valid();)
178
179#ifdef PB_DS_HT_MAP_RESIZE_TRACE_
180	std::cerr << "hlcrt::notify_externally_resized1 " <<
181        static_cast<unsigned long>(new_size) << "    " <<
182        static_cast<unsigned long>(m_load_min) << "    " <<
183        static_cast<unsigned long>(m_load_max) << "    " <<
184        static_cast<unsigned long>(m_next_shrink_size) << " " <<
185        static_cast<unsigned long>(m_next_grow_size) << "    " << std::endl;
186#endif
187      return;
188    }
189
190  _GLIBCXX_DEBUG_ASSERT(new_shrink_size <= m_next_shrink_size);
191  m_next_shrink_size = new_shrink_size;
192
193#ifdef PB_DS_HT_MAP_RESIZE_TRACE_
194  std::cerr << "hlcrt::notify_externally_resized2 " <<
195    static_cast<unsigned long>(new_size) << "    " <<
196    static_cast<unsigned long>(m_load_min) << "    " <<
197    static_cast<unsigned long>(m_load_max) << "    " <<
198    static_cast<unsigned long>(m_next_shrink_size) << " " <<
199    static_cast<unsigned long>(m_next_grow_size) << "    " << std::endl;
200#endif
201
202  _GLIBCXX_DEBUG_ONLY(assert_valid();)
203}
204
205PB_DS_CLASS_T_DEC
206void
207PB_DS_CLASS_C_DEC::
208notify_cleared()
209{
210  _GLIBCXX_DEBUG_ONLY(assert_valid();)
211  size_base::set_size(0);
212  m_resize_needed = (0 < m_next_shrink_size);
213  _GLIBCXX_DEBUG_ONLY(assert_valid();)
214}
215
216PB_DS_CLASS_T_DEC
217void
218PB_DS_CLASS_C_DEC::
219swap(PB_DS_CLASS_C_DEC& other)
220{
221  _GLIBCXX_DEBUG_ONLY(assert_valid();)
222  _GLIBCXX_DEBUG_ONLY(other.assert_valid();)
223
224  size_base::swap(other);
225  std::swap(m_load_min, other.m_load_min);
226  std::swap(m_load_max, other.m_load_max);
227  std::swap(m_resize_needed, other.m_resize_needed);
228  std::swap(m_next_grow_size, other.m_next_grow_size);
229  std::swap(m_next_shrink_size, other.m_next_shrink_size);
230
231  _GLIBCXX_DEBUG_ONLY(assert_valid();)
232  _GLIBCXX_DEBUG_ONLY(other.assert_valid();)
233}
234
235PB_DS_CLASS_T_DEC
236inline std::pair<float, float>
237PB_DS_CLASS_C_DEC::
238get_loads() const
239{
240  PB_DS_STATIC_ASSERT(access, external_load_access);
241  return std::make_pair(m_load_min, m_load_max);
242}
243
244PB_DS_CLASS_T_DEC
245void
246PB_DS_CLASS_C_DEC::
247set_loads(std::pair<float, float> load_pair)
248{
249  PB_DS_STATIC_ASSERT(access, external_load_access);
250  const float old_load_min = m_load_min;
251  const float old_load_max = m_load_max;
252  const size_type old_next_shrink_size = m_next_shrink_size;
253  const size_type old_next_grow_size = m_next_grow_size;
254  const bool old_resize_needed = m_resize_needed;
255
256  __try
257    {
258      m_load_min = load_pair.first;
259      m_load_max = load_pair.second;
260      do_resize(static_cast<size_type>(size_base::get_size() / ((m_load_min + m_load_max) / 2)));
261    }
262  __catch(...)
263    {
264      m_load_min = old_load_min;
265      m_load_max = old_load_max;
266      m_next_shrink_size = old_next_shrink_size;
267      m_next_grow_size = old_next_grow_size;
268      m_resize_needed = old_resize_needed;
269      __throw_exception_again;
270    }
271}
272
273PB_DS_CLASS_T_DEC
274void
275PB_DS_CLASS_C_DEC::
276do_resize(size_type)
277{ std::abort(); }
278
279#ifdef _GLIBCXX_DEBUG
280PB_DS_CLASS_T_DEC
281void
282PB_DS_CLASS_C_DEC::
283assert_valid() const
284{
285  _GLIBCXX_DEBUG_ASSERT(m_load_max > m_load_min);
286  _GLIBCXX_DEBUG_ASSERT(m_next_grow_size >= m_next_shrink_size);
287}
288#endif
289
290