1// -*- C++ -*-
2
3// Copyright (C) 2005, 2006 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 2, 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// You should have received a copy of the GNU General Public License
17// along with this library; see the file COPYING.  If not, write to
18// the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
19// MA 02111-1307, USA.
20
21// As a special exception, you may use this file as part of a free
22// software library without restriction.  Specifically, if other files
23// instantiate templates or use macros or inline functions from this
24// file, or you compile this file and link it with other files to
25// produce an executable, this file does not by itself cause the
26// resulting executable to be covered by the GNU General Public
27// License.  This exception does not however invalidate any other
28// reasons why the executable file might be covered by the GNU General
29// Public License.
30
31// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
32
33// Permission to use, copy, modify, sell, and distribute this software
34// is hereby granted without fee, provided that the above copyright
35// notice appears in all copies, and that both that copyright notice
36// and this permission notice appear in supporting documentation. None
37// of the above authors, nor IBM Haifa Research Laboratories, make any
38// representation about the suitability of this software for any
39// purpose. It is provided "as is" without express or implied
40// warranty.
41
42/**
43 * @file cc_hash_max_collision_check_resize_trigger_imp.hpp
44 * Contains a resize trigger implementation.
45 */
46
47#define PB_DS_STATIC_ASSERT(UNIQUE, E) \
48  typedef detail::static_assert_dumclass<sizeof(detail::static_assert<(bool)(E)>)> UNIQUE##static_assert_type
49
50PB_DS_CLASS_T_DEC
51PB_DS_CLASS_C_DEC::
52cc_hash_max_collision_check_resize_trigger(float load) :
53  m_load(load),
54  m_size(0),
55  m_num_col(0),
56  m_max_col(0),
57  m_resize_needed(false)
58{ }
59
60PB_DS_CLASS_T_DEC
61inline void
62PB_DS_CLASS_C_DEC::
63notify_find_search_start()
64{ }
65
66PB_DS_CLASS_T_DEC
67inline void
68PB_DS_CLASS_C_DEC::
69notify_find_search_collision()
70{ }
71
72PB_DS_CLASS_T_DEC
73inline void
74PB_DS_CLASS_C_DEC::
75notify_find_search_end()
76{ }
77
78PB_DS_CLASS_T_DEC
79inline void
80PB_DS_CLASS_C_DEC::
81notify_insert_search_start()
82{ m_num_col = 0; }
83
84PB_DS_CLASS_T_DEC
85inline void
86PB_DS_CLASS_C_DEC::
87notify_insert_search_collision()
88{ ++m_num_col; }
89
90PB_DS_CLASS_T_DEC
91inline void
92PB_DS_CLASS_C_DEC::
93notify_insert_search_end()
94{ calc_resize_needed(); }
95
96PB_DS_CLASS_T_DEC
97inline void
98PB_DS_CLASS_C_DEC::
99notify_erase_search_start()
100{ }
101
102PB_DS_CLASS_T_DEC
103inline void
104PB_DS_CLASS_C_DEC::
105notify_erase_search_collision()
106{ }
107
108PB_DS_CLASS_T_DEC
109inline void
110PB_DS_CLASS_C_DEC::
111notify_erase_search_end()
112{ }
113
114PB_DS_CLASS_T_DEC
115inline void
116PB_DS_CLASS_C_DEC::
117notify_inserted(size_type)
118{ }
119
120PB_DS_CLASS_T_DEC
121inline void
122PB_DS_CLASS_C_DEC::
123notify_erased(size_type)
124{ m_resize_needed = true; }
125
126PB_DS_CLASS_T_DEC
127void
128PB_DS_CLASS_C_DEC::
129notify_cleared()
130{ m_resize_needed = false; }
131
132PB_DS_CLASS_T_DEC
133inline bool
134PB_DS_CLASS_C_DEC::
135is_resize_needed() const
136{ return m_resize_needed; }
137
138PB_DS_CLASS_T_DEC
139inline bool
140PB_DS_CLASS_C_DEC::
141is_grow_needed(size_type /*size*/, size_type /*num_used_e*/) const
142{ return m_num_col >= m_max_col; }
143
144PB_DS_CLASS_T_DEC
145void
146PB_DS_CLASS_C_DEC::
147notify_resized(size_type new_size)
148{
149  m_size = new_size;
150
151#ifdef PB_DS_HT_MAP_RESIZE_TRACE_
152  std::cerr << "chmccrt::notify_resized "
153	    << static_cast<unsigned long>(new_size) << std::endl;
154#endif
155
156  calc_max_num_coll();
157  calc_resize_needed();
158  m_num_col = 0;
159}
160
161PB_DS_CLASS_T_DEC
162void
163PB_DS_CLASS_C_DEC::
164calc_max_num_coll()
165{
166  // max_col <-- \sqrt{2 load \ln( 2 m \ln( m ) ) }
167  const double ln_arg = 2 * m_size * ::log(double(m_size));
168  m_max_col = size_type(::ceil(::sqrt(2 * m_load * ::log(ln_arg))));
169
170#ifdef PB_DS_HT_MAP_RESIZE_TRACE_
171  std::cerr << "chmccrt::calc_max_num_coll "
172	    << static_cast<unsigned long>(m_size) <<    "    "
173	    << static_cast<unsigned long>(m_max_col) << std::endl;
174#endif
175}
176
177PB_DS_CLASS_T_DEC
178void
179PB_DS_CLASS_C_DEC::
180notify_externally_resized(size_type new_size)
181{ notify_resized(new_size); }
182
183PB_DS_CLASS_T_DEC
184void
185PB_DS_CLASS_C_DEC::
186swap(PB_DS_CLASS_C_DEC& other)
187{
188  std::swap(m_load, other.m_load);
189  std::swap(m_size, other.m_size);
190  std::swap(m_num_col, other.m_num_col);
191  std::swap(m_max_col, other.m_max_col);
192  std::swap(m_resize_needed, other.m_resize_needed);
193}
194
195PB_DS_CLASS_T_DEC
196inline float
197PB_DS_CLASS_C_DEC::
198get_load() const
199{
200  PB_DS_STATIC_ASSERT(access, external_load_access);
201  return m_load;
202}
203
204PB_DS_CLASS_T_DEC
205inline void
206PB_DS_CLASS_C_DEC::
207calc_resize_needed()
208{ m_resize_needed = m_resize_needed || m_num_col >= m_max_col; }
209
210PB_DS_CLASS_T_DEC
211void
212PB_DS_CLASS_C_DEC::
213set_load(float load)
214{
215  PB_DS_STATIC_ASSERT(access, external_load_access);
216  m_load = load;
217  calc_max_num_coll();
218  calc_resize_needed();
219}
220
221#undef PB_DS_STATIC_ASSERT
222