1// -*- C++ -*-
2
3// Copyright (C) 2005-2015 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
41PB_DS_CLASS_T_DEC
42void
43PB_DS_CLASS_C_DEC::
44clear()
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
65PB_DS_CLASS_T_DEC
66void
67PB_DS_CLASS_C_DEC::
68erase_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
74PB_DS_CLASS_T_DEC
75void
76PB_DS_CLASS_C_DEC::
77erase_at(entry_pointer, size_type, true_type)
78{ }
79
80PB_DS_CLASS_T_DEC
81inline void
82PB_DS_CLASS_C_DEC::
83pop()
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
97PB_DS_CLASS_T_DEC
98template<typename Pred>
99typename PB_DS_CLASS_C_DEC::size_type
100PB_DS_CLASS_C_DEC::
101erase_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
134PB_DS_CLASS_T_DEC
135inline void
136PB_DS_CLASS_C_DEC::
137erase(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
157PB_DS_CLASS_T_DEC
158inline void
159PB_DS_CLASS_C_DEC::
160resize_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
181PB_DS_CLASS_T_DEC
182template<typename Pred>
183typename PB_DS_CLASS_C_DEC::size_type
184PB_DS_CLASS_C_DEC::
185partition(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}
209