libstdc++

binary_heap_/erase_fn_imps.hpp
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1 // -*- C++ -*-
2
3 // Copyright (C) 2005-2013 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 }