libstdc++-v3/include/ext/pb_ds/detail/resize_policy/hash_load_check_resize_trigger_imp.hpp

   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 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
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  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
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  37 // of the above authors, nor IBM Haifa Research Laboratories, make any
  38 // representation about the suitability of this software for any
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  40 // warranty.
  41
  42 /**
  43  * @file hash_load_check_resize_trigger_imp.hpp
  44  * Contains a resize trigger implementation.
  45  */
  46
  47 PB_DS_CLASS_T_DEC
  48 PB_DS_CLASS_C_DEC::
  49 hash_load_check_resize_trigger(float load_min, float load_max)
  50 : m_load_min(load_min), m_load_max(load_max), m_next_shrink_size(0),
  51   m_next_grow_size(0), m_resize_needed(false)
  52 { _GLIBCXX_DEBUG_ONLY(assert_valid();) }
  53
  54 PB_DS_CLASS_T_DEC
  55 inline void
  56 PB_DS_CLASS_C_DEC::
  57 notify_find_search_start()
  58 { _GLIBCXX_DEBUG_ONLY(assert_valid();) }
  59
  60 PB_DS_CLASS_T_DEC
  61 inline void
  62 PB_DS_CLASS_C_DEC::
  63 notify_find_search_collision()
  64 { _GLIBCXX_DEBUG_ONLY(assert_valid();) }
  65
  66 PB_DS_CLASS_T_DEC
  67 inline void
  68 PB_DS_CLASS_C_DEC::
  69 notify_find_search_end()
  70 { _GLIBCXX_DEBUG_ONLY(assert_valid();) }
  71
  72 PB_DS_CLASS_T_DEC
  73 inline void
  74 PB_DS_CLASS_C_DEC::
  75 notify_insert_search_start()
  76 { _GLIBCXX_DEBUG_ONLY(assert_valid();) }
  77
  78 PB_DS_CLASS_T_DEC
  79 inline void
  80 PB_DS_CLASS_C_DEC::
  81 notify_insert_search_collision()
  82 { _GLIBCXX_DEBUG_ONLY(assert_valid();) }
  83
  84 PB_DS_CLASS_T_DEC
  85 inline void
  86 PB_DS_CLASS_C_DEC::
  87 notify_insert_search_end()
  88 { _GLIBCXX_DEBUG_ONLY(assert_valid();) }
  89
  90 PB_DS_CLASS_T_DEC
  91 inline void
  92 PB_DS_CLASS_C_DEC::
  93 notify_erase_search_start()
  94 { _GLIBCXX_DEBUG_ONLY(assert_valid();) }
  95
  96 PB_DS_CLASS_T_DEC
  97 inline void
  98 PB_DS_CLASS_C_DEC::
  99 notify_erase_search_collision()
 100 { _GLIBCXX_DEBUG_ONLY(assert_valid();) }
 101
 102 PB_DS_CLASS_T_DEC
 103 inline void
 104 PB_DS_CLASS_C_DEC::
 105 notify_erase_search_end()
 106 { _GLIBCXX_DEBUG_ONLY(assert_valid();) }
 107
 108 PB_DS_CLASS_T_DEC
 109 inline void
 110 PB_DS_CLASS_C_DEC::
 111 notify_inserted(size_type num_entries)
 112 {
 113   m_resize_needed = (num_entries >= m_next_grow_size);
 114   size_base::set_size(num_entries);
 115   _GLIBCXX_DEBUG_ONLY(assert_valid();)
 116 }
 117
 118 PB_DS_CLASS_T_DEC
 119 inline void
 120 PB_DS_CLASS_C_DEC::
 121 notify_erased(size_type num_entries)
 122 {
 123   size_base::set_size(num_entries);
 124   m_resize_needed = num_entries <= m_next_shrink_size;
 125   _GLIBCXX_DEBUG_ONLY(assert_valid();)
 126 }
 127
 128 PB_DS_CLASS_T_DEC
 129 inline bool
 130 PB_DS_CLASS_C_DEC::
 131 is_resize_needed() const
 132 {
 133   _GLIBCXX_DEBUG_ONLY(assert_valid();)
 134   return m_resize_needed;
 135 }
 136
 137 PB_DS_CLASS_T_DEC
 138 inline bool
 139 PB_DS_CLASS_C_DEC::
 140 is_grow_needed(size_type /*size*/, size_type num_entries) const
 141 {
 142   _GLIBCXX_DEBUG_ASSERT(m_resize_needed);
 143   return num_entries >= m_next_grow_size;
 144 }
 145
 146 PB_DS_CLASS_T_DEC
 147 PB_DS_CLASS_C_DEC::
 148 ~hash_load_check_resize_trigger() { }
 149
 150 PB_DS_CLASS_T_DEC
 151 void
 152 PB_DS_CLASS_C_DEC::
 153 notify_resized(size_type new_size)
 154 {
 155   m_resize_needed = false;
 156   m_next_grow_size = size_type(m_load_max * new_size - 1);
 157   m_next_shrink_size = size_type(m_load_min * new_size);
 158
 159 #ifdef PB_DS_HT_MAP_RESIZE_TRACE_
 160   std::cerr << "hlcrt::notify_resized " <<
 161     static_cast<unsigned long>(new_size) << "    " <<
 162     static_cast<unsigned long>(m_load_min) << "    " <<
 163     static_cast<unsigned long>(m_load_max) << "    " <<
 164     static_cast<unsigned long>(m_next_shrink_size) << " " <<
 165     static_cast<unsigned long>(m_next_grow_size) << "    " << std::endl;
 166 #endif
 167
 168   _GLIBCXX_DEBUG_ONLY(assert_valid();)
 169 }
 170
 171 PB_DS_CLASS_T_DEC
 172 void
 173 PB_DS_CLASS_C_DEC::
 174 notify_externally_resized(size_type new_size)
 175 {
 176   m_resize_needed = false;
 177   size_type new_grow_size = size_type(m_load_max * new_size - 1);
 178   size_type new_shrink_size = size_type(m_load_min * new_size);
 179   if (new_grow_size >= m_next_grow_size)
 180     {
 181       _GLIBCXX_DEBUG_ASSERT(new_shrink_size > m_next_shrink_size);
 182       m_next_grow_size = new_grow_size;
 183       _GLIBCXX_DEBUG_ONLY(assert_valid();)
 184
 185 #ifdef PB_DS_HT_MAP_RESIZE_TRACE_
 186         std::cerr << "hlcrt::notify_externally_resized1 " <<
 187         static_cast<unsigned long>(new_size) << "    " <<
 188         static_cast<unsigned long>(m_load_min) << "    " <<
 189         static_cast<unsigned long>(m_load_max) << "    " <<
 190         static_cast<unsigned long>(m_next_shrink_size) << " " <<
 191         static_cast<unsigned long>(m_next_grow_size) << "    " << std::endl;
 192 #endif
 193       return;
 194     }
 195
 196   _GLIBCXX_DEBUG_ASSERT(new_shrink_size <= m_next_shrink_size);
 197   m_next_shrink_size = new_shrink_size;
 198
 199 #ifdef PB_DS_HT_MAP_RESIZE_TRACE_
 200   std::cerr << "hlcrt::notify_externally_resized2 " <<
 201     static_cast<unsigned long>(new_size) << "    " <<
 202     static_cast<unsigned long>(m_load_min) << "    " <<
 203     static_cast<unsigned long>(m_load_max) << "    " <<
 204     static_cast<unsigned long>(m_next_shrink_size) << " " <<
 205     static_cast<unsigned long>(m_next_grow_size) << "    " << std::endl;
 206 #endif
 207
 208   _GLIBCXX_DEBUG_ONLY(assert_valid();)
 209 }
 210
 211 PB_DS_CLASS_T_DEC
 212 void
 213 PB_DS_CLASS_C_DEC::
 214 notify_cleared()
 215 {
 216   _GLIBCXX_DEBUG_ONLY(assert_valid();)
 217   size_base::set_size(0);
 218   m_resize_needed = (0 < m_next_shrink_size);
 219   _GLIBCXX_DEBUG_ONLY(assert_valid();)
 220 }
 221
 222 PB_DS_CLASS_T_DEC
 223 void
 224 PB_DS_CLASS_C_DEC::
 225 swap(PB_DS_CLASS_C_DEC& other)
 226 {
 227   _GLIBCXX_DEBUG_ONLY(assert_valid();)
 228   _GLIBCXX_DEBUG_ONLY(other.assert_valid();)
 229
 230   size_base::swap(other);
 231   std::swap(m_load_min, other.m_load_min);
 232   std::swap(m_load_max, other.m_load_max);
 233   std::swap(m_resize_needed, other.m_resize_needed);
 234   std::swap(m_next_grow_size, other.m_next_grow_size);
 235   std::swap(m_next_shrink_size, other.m_next_shrink_size);
 236
 237   _GLIBCXX_DEBUG_ONLY(assert_valid();)
 238   _GLIBCXX_DEBUG_ONLY(other.assert_valid();)
 239 }
 240
 241 PB_DS_CLASS_T_DEC
 242 inline std::pair<float, float>
 243 PB_DS_CLASS_C_DEC::
 244 get_loads() const
 245 {
 246   PB_DS_STATIC_ASSERT(access, external_load_access);
 247   return std::make_pair(m_load_min, m_load_max);
 248 }
 249
 250 PB_DS_CLASS_T_DEC
 251 void
 252 PB_DS_CLASS_C_DEC::
 253 set_loads(std::pair<float, float> load_pair)
 254 {
 255   PB_DS_STATIC_ASSERT(access, external_load_access);
 256   const float old_load_min = m_load_min;
 257   const float old_load_max = m_load_max;
 258   const size_type old_next_shrink_size = m_next_shrink_size;
 259   const size_type old_next_grow_size = m_next_grow_size;
 260   const bool old_resize_needed = m_resize_needed;
 261
 262   __try
 263     {
 264       m_load_min = load_pair.first;
 265       m_load_max = load_pair.second;
 266       do_resize(static_cast<size_type>(size_base::get_size() / ((m_load_min + m_load_max) / 2)));
 267     }
 268   __catch(...)
 269     {
 270       m_load_min = old_load_min;
 271       m_load_max = old_load_max;
 272       m_next_shrink_size = old_next_shrink_size;
 273       m_next_grow_size = old_next_grow_size;
 274       m_resize_needed = old_resize_needed;
 275       __throw_exception_again;
 276     }
 277 }
 278
 279 PB_DS_CLASS_T_DEC
 280 void
 281 PB_DS_CLASS_C_DEC::
 282 do_resize(size_type)
 283 { std::abort(); }
 284
 285 #ifdef _GLIBCXX_DEBUG
 286 PB_DS_CLASS_T_DEC
 287 void
 288 PB_DS_CLASS_C_DEC::
 289 assert_valid() const
 290 {
 291   _GLIBCXX_DEBUG_ASSERT(m_load_max > m_load_min);
 292   _GLIBCXX_DEBUG_ASSERT(m_next_grow_size >= m_next_shrink_size);
 293 }
 294 #endif
 295