libstdc++-v3/include/ext/pb_ds/detail/binary_heap_/erase_fn_imps.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2018 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 binary_heap_/erase_fn_imps.hpp
  38  * Contains an implementation class for a binary_heap.
  39  */
  40
  41 PB_DS_CLASS_T_DEC
  42 void
  43 PB_DS_CLASS_C_DEC::
  44 clear()
  45 {
  46   for (size_type i = 0; i < m_size; ++i)
  47     erase_at(m_a_entries, i, s_no_throw_copies_ind);
  48
  49   __try
  50     {
  51       const size_type new_size = resize_policy::get_new_size_for_arbitrary(0);
  52       entry_pointer new_entries = s_entry_allocator.allocate(new_size);
  53       resize_policy::notify_arbitrary(new_size);
  54       s_entry_allocator.deallocate(m_a_entries, m_actual_size);
  55       m_actual_size = new_size;
  56       m_a_entries = new_entries;
  57     }
  58   __catch(...)
  59     { }
  60
  61   m_size = 0;
  62   PB_DS_ASSERT_VALID((*this))
  63 }
  64
  65 PB_DS_CLASS_T_DEC
  66 void
  67 PB_DS_CLASS_C_DEC::
  68 erase_at(entry_pointer a_entries, size_type i, false_type)
  69 {
  70   a_entries[i]->~value_type();
  71   s_value_allocator.deallocate(a_entries[i], 1);
  72 }
  73
  74 PB_DS_CLASS_T_DEC
  75 void
  76 PB_DS_CLASS_C_DEC::
  77 erase_at(entry_pointer, size_type, true_type)
  78 { }
  79
  80 PB_DS_CLASS_T_DEC
  81 inline void
  82 PB_DS_CLASS_C_DEC::
  83 pop()
  84 {
  85   PB_DS_ASSERT_VALID((*this))
  86   _GLIBCXX_DEBUG_ASSERT(!empty());
  87
  88   pop_heap();
  89   erase_at(m_a_entries, m_size - 1, s_no_throw_copies_ind);
  90   resize_for_erase_if_needed();
  91   _GLIBCXX_DEBUG_ASSERT(m_size > 0);
  92   --m_size;
  93
  94   PB_DS_ASSERT_VALID((*this))
  95 }
  96
  97 PB_DS_CLASS_T_DEC
  98 template<typename Pred>
  99 typename PB_DS_CLASS_C_DEC::size_type
 100 PB_DS_CLASS_C_DEC::
 101 erase_if(Pred pred)
 102 {
 103   PB_DS_ASSERT_VALID((*this))
 104
 105   typedef typename entry_pred<value_type, Pred, _Alloc, simple_value>::type
 106     pred_t;
 107
 108   const size_type left = partition(pred_t(pred));
 109   _GLIBCXX_DEBUG_ASSERT(m_size >= left);
 110   const size_type ersd = m_size - left;
 111   for (size_type i = left; i < m_size; ++i)
 112     erase_at(m_a_entries, i, s_no_throw_copies_ind);
 113
 114   __try
 115     {
 116       const size_type new_size =
 117         resize_policy::get_new_size_for_arbitrary(left);
 118
 119       entry_pointer new_entries = s_entry_allocator.allocate(new_size);
 120       std::copy(m_a_entries, m_a_entries + left, new_entries);
 121       s_entry_allocator.deallocate(m_a_entries, m_actual_size);
 122       m_actual_size = new_size;
 123       resize_policy::notify_arbitrary(m_actual_size);
 124     }
 125   __catch(...)
 126     { };
 127
 128   m_size = left;
 129   make_heap();
 130   PB_DS_ASSERT_VALID((*this))
 131   return ersd;
 132 }
 133
 134 PB_DS_CLASS_T_DEC
 135 inline void
 136 PB_DS_CLASS_C_DEC::
 137 erase(point_iterator it)
 138 {
 139   PB_DS_ASSERT_VALID((*this))
 140   _GLIBCXX_DEBUG_ASSERT(!empty());
 141
 142   const size_type fix_pos = it.m_p_e - m_a_entries;
 143   std::swap(*it.m_p_e, m_a_entries[m_size - 1]);
 144   erase_at(m_a_entries, m_size - 1, s_no_throw_copies_ind);
 145   resize_for_erase_if_needed();
 146
 147   _GLIBCXX_DEBUG_ASSERT(m_size > 0);
 148   --m_size;
 149   _GLIBCXX_DEBUG_ASSERT(fix_pos <= m_size);
 150
 151   if (fix_pos != m_size)
 152     fix(m_a_entries + fix_pos);
 153
 154   PB_DS_ASSERT_VALID((*this))
 155 }
 156
 157 PB_DS_CLASS_T_DEC
 158 inline void
 159 PB_DS_CLASS_C_DEC::
 160 resize_for_erase_if_needed()
 161 {
 162   if (!resize_policy::resize_needed_for_shrink(m_size))
 163     return;
 164
 165   __try
 166     {
 167       const size_type new_size = resize_policy::get_new_size_for_shrink();
 168       entry_pointer new_entries = s_entry_allocator.allocate(new_size);
 169       resize_policy::notify_shrink_resize();
 170
 171       _GLIBCXX_DEBUG_ASSERT(m_size > 0);
 172       std::copy(m_a_entries, m_a_entries + m_size - 1, new_entries);
 173       s_entry_allocator.deallocate(m_a_entries, m_actual_size);
 174       m_actual_size = new_size;
 175       m_a_entries = new_entries;
 176     }
 177   __catch(...)
 178     { }
 179 }
 180
 181 PB_DS_CLASS_T_DEC
 182 template<typename Pred>
 183 typename PB_DS_CLASS_C_DEC::size_type
 184 PB_DS_CLASS_C_DEC::
 185 partition(Pred pred)
 186 {
 187   size_type left = 0;
 188   size_type right = m_size - 1;
 189
 190   while (right + 1 != left)
 191     {
 192       _GLIBCXX_DEBUG_ASSERT(left <= m_size);
 193
 194       if (!pred(m_a_entries[left]))
 195         ++left;
 196       else if (pred(m_a_entries[right]))
 197         --right;
 198       else
 199         {
 200           _GLIBCXX_DEBUG_ASSERT(left < right);
 201           std::swap(m_a_entries[left], m_a_entries[right]);
 202           ++left;
 203           --right;
 204         }
 205     }
 206
 207   return left;
 208 }