libstdc++
binary_heap_/erase_fn_imps.hpp
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1 // -*- C++ -*-
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3 // Copyright (C) 2005, 2006, 2007, 2008, 2009, 2011
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17 // Under Section 7 of GPL version 3, you are granted additional
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19 // 3.1, as published by the Free Software Foundation.
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26 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
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29 // is hereby granted without fee, provided that the above copyright
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36 
37 /**
38  * @file binary_heap_/erase_fn_imps.hpp
39  * Contains an implementation class for a binary_heap.
40  */
41 
42 PB_DS_CLASS_T_DEC
43 void
44 PB_DS_CLASS_C_DEC::
45 clear()
46 {
47  for (size_type i = 0; i < m_size; ++i)
48  erase_at(m_a_entries, i, s_no_throw_copies_ind);
49 
50  __try
51  {
52  const size_type new_size = resize_policy::get_new_size_for_arbitrary(0);
53  entry_pointer new_entries = s_entry_allocator.allocate(new_size);
54  resize_policy::notify_arbitrary(new_size);
55  s_entry_allocator.deallocate(m_a_entries, m_actual_size);
56  m_actual_size = new_size;
57  m_a_entries = new_entries;
58  }
59  __catch(...)
60  { }
61 
62  m_size = 0;
63  PB_DS_ASSERT_VALID((*this))
64 }
65 
66 PB_DS_CLASS_T_DEC
67 void
68 PB_DS_CLASS_C_DEC::
69 erase_at(entry_pointer a_entries, size_type i, false_type)
70 {
71  a_entries[i]->~value_type();
72  s_value_allocator.deallocate(a_entries[i], 1);
73 }
74 
75 PB_DS_CLASS_T_DEC
76 void
77 PB_DS_CLASS_C_DEC::
78 erase_at(entry_pointer, size_type, true_type)
79 { }
80 
81 PB_DS_CLASS_T_DEC
82 inline void
83 PB_DS_CLASS_C_DEC::
84 pop()
85 {
86  PB_DS_ASSERT_VALID((*this))
87  _GLIBCXX_DEBUG_ASSERT(!empty());
88 
89  pop_heap();
90  erase_at(m_a_entries, m_size - 1, s_no_throw_copies_ind);
91  resize_for_erase_if_needed();
92  _GLIBCXX_DEBUG_ASSERT(m_size > 0);
93  --m_size;
94 
95  PB_DS_ASSERT_VALID((*this))
96 }
97 
98 PB_DS_CLASS_T_DEC
99 template<typename Pred>
100 typename PB_DS_CLASS_C_DEC::size_type
101 PB_DS_CLASS_C_DEC::
102 erase_if(Pred pred)
103 {
104  PB_DS_ASSERT_VALID((*this))
105 
106  typedef typename entry_pred<value_type, Pred, _Alloc, simple_value>::type
107  pred_t;
108 
109  const size_type left = partition(pred_t(pred));
110  _GLIBCXX_DEBUG_ASSERT(m_size >= left);
111  const size_type ersd = m_size - left;
112  for (size_type i = left; i < m_size; ++i)
113  erase_at(m_a_entries, i, s_no_throw_copies_ind);
114 
115  __try
116  {
117  const size_type new_size =
118  resize_policy::get_new_size_for_arbitrary(left);
119 
120  entry_pointer new_entries = s_entry_allocator.allocate(new_size);
121  std::copy(m_a_entries, m_a_entries + left, new_entries);
122  s_entry_allocator.deallocate(m_a_entries, m_actual_size);
123  m_actual_size = new_size;
124  resize_policy::notify_arbitrary(m_actual_size);
125  }
126  __catch(...)
127  { };
128 
129  m_size = left;
130  make_heap();
131  PB_DS_ASSERT_VALID((*this))
132  return ersd;
133 }
134 
135 PB_DS_CLASS_T_DEC
136 inline void
137 PB_DS_CLASS_C_DEC::
138 erase(point_iterator it)
139 {
140  PB_DS_ASSERT_VALID((*this))
141  _GLIBCXX_DEBUG_ASSERT(!empty());
142 
143  const size_type fix_pos = it.m_p_e - m_a_entries;
144  std::swap(*it.m_p_e, m_a_entries[m_size - 1]);
145  erase_at(m_a_entries, m_size - 1, s_no_throw_copies_ind);
146  resize_for_erase_if_needed();
147 
148  _GLIBCXX_DEBUG_ASSERT(m_size > 0);
149  --m_size;
150  _GLIBCXX_DEBUG_ASSERT(fix_pos <= m_size);
151 
152  if (fix_pos != m_size)
153  fix(m_a_entries + fix_pos);
154 
155  PB_DS_ASSERT_VALID((*this))
156 }
157 
158 PB_DS_CLASS_T_DEC
159 inline void
160 PB_DS_CLASS_C_DEC::
161 resize_for_erase_if_needed()
162 {
163  if (!resize_policy::resize_needed_for_shrink(m_size))
164  return;
165 
166  __try
167  {
168  const size_type new_size = resize_policy::get_new_size_for_shrink();
169  entry_pointer new_entries = s_entry_allocator.allocate(new_size);
170  resize_policy::notify_shrink_resize();
171 
172  _GLIBCXX_DEBUG_ASSERT(m_size > 0);
173  std::copy(m_a_entries, m_a_entries + m_size - 1, new_entries);
174  s_entry_allocator.deallocate(m_a_entries, m_actual_size);
175  m_actual_size = new_size;
176  m_a_entries = new_entries;
177  }
178  __catch(...)
179  { }
180 }
181 
182 PB_DS_CLASS_T_DEC
183 template<typename Pred>
184 typename PB_DS_CLASS_C_DEC::size_type
185 PB_DS_CLASS_C_DEC::
186 partition(Pred pred)
187 {
188  size_type left = 0;
189  size_type right = m_size - 1;
190 
191  while (right + 1 != left)
192  {
193  _GLIBCXX_DEBUG_ASSERT(left <= m_size);
194 
195  if (!pred(m_a_entries[left]))
196  ++left;
197  else if (pred(m_a_entries[right]))
198  --right;
199  else
200  {
201  _GLIBCXX_DEBUG_ASSERT(left < right);
202  std::swap(m_a_entries[left], m_a_entries[right]);
203  ++left;
204  --right;
205  }
206  }
207 
208  return left;
209 }