libstdc++
pat_trie_/erase_fn_imps.hpp
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25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
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35 
36 /**
37  * @file pat_trie_/erase_fn_imps.hpp
38  * Contains an implementation class for pat_trie.
39  */
40 
41 PB_DS_CLASS_T_DEC
42 inline bool
43 PB_DS_CLASS_C_DEC::
44 erase(key_const_reference r_key)
45 {
46  node_pointer p_nd = find_imp(r_key);
47  if (p_nd == 0 || p_nd->m_type == i_node)
48  {
49  PB_DS_CHECK_KEY_DOES_NOT_EXIST(r_key)
50  return false;
51  }
52 
53  _GLIBCXX_DEBUG_ASSERT(p_nd->m_type == leaf_node);
54  if (!synth_access_traits::equal_keys(PB_DS_V2F(reinterpret_cast<leaf_pointer>(p_nd)->value()), r_key))
55  {
56  PB_DS_CHECK_KEY_DOES_NOT_EXIST(r_key)
57  return false;
58  }
59 
60  PB_DS_CHECK_KEY_EXISTS(r_key)
61  erase_leaf(static_cast<leaf_pointer>(p_nd));
62  PB_DS_ASSERT_VALID((*this))
63  return true;
64 }
65 
66 PB_DS_CLASS_T_DEC
67 void
68 PB_DS_CLASS_C_DEC::
69 erase_fixup(inode_pointer p_nd)
70 {
71  _GLIBCXX_DEBUG_ASSERT(std::distance(p_nd->begin(), p_nd->end()) >= 1);
72  if (std::distance(p_nd->begin(), p_nd->end()) == 1)
73  {
74  node_pointer p_parent = p_nd->m_p_parent;
75  if (p_parent == m_p_head)
76  m_p_head->m_p_parent = *p_nd->begin();
77  else
78  {
79  _GLIBCXX_DEBUG_ASSERT(p_parent->m_type == i_node);
80  node_pointer p_new_child = *p_nd->begin();
81 
82  typedef inode_pointer inode_ptr;
83  inode_ptr p_internal = static_cast<inode_ptr>(p_parent);
84  p_internal->replace_child(p_new_child, pref_begin(p_new_child),
85  pref_end(p_new_child), this);
86  }
87  (*p_nd->begin())->m_p_parent = p_nd->m_p_parent;
88  p_nd->~inode();
89  s_inode_allocator.deallocate(p_nd, 1);
90 
91  if (p_parent == m_p_head)
92  return;
93 
94  _GLIBCXX_DEBUG_ASSERT(p_parent->m_type == i_node);
95  p_nd = static_cast<inode_pointer>(p_parent);
96  }
97 
98  while (true)
99  {
100  _GLIBCXX_DEBUG_ASSERT(std::distance(p_nd->begin(), p_nd->end()) > 1);
101  p_nd->update_prefixes(this);
102  apply_update(p_nd, (node_update*)this);
103  PB_DS_ASSERT_NODE_VALID(p_nd)
104  if (p_nd->m_p_parent->m_type == head_node)
105  return;
106 
107  _GLIBCXX_DEBUG_ASSERT(p_nd->m_p_parent->m_type == i_node);
108 
109  p_nd = static_cast<inode_pointer>(p_nd->m_p_parent);
110  }
111 }
112 
113 PB_DS_CLASS_T_DEC
114 inline void
115 PB_DS_CLASS_C_DEC::
116 actual_erase_leaf(leaf_pointer p_l)
117 {
118  _GLIBCXX_DEBUG_ASSERT(m_size > 0);
119  --m_size;
120  _GLIBCXX_DEBUG_ONLY(debug_base::erase_existing(PB_DS_V2F(p_l->value())));
121  p_l->~leaf();
122  s_leaf_allocator.deallocate(p_l, 1);
123 }
124 
125 PB_DS_CLASS_T_DEC
126 void
127 PB_DS_CLASS_C_DEC::
128 clear()
129 {
130  if (!empty())
131  {
132  clear_imp(m_p_head->m_p_parent);
133  m_size = 0;
134  initialize();
135  _GLIBCXX_DEBUG_ONLY(debug_base::clear();)
136  PB_DS_ASSERT_VALID((*this))
137  }
138 }
139 
140 PB_DS_CLASS_T_DEC
141 void
142 PB_DS_CLASS_C_DEC::
143 clear_imp(node_pointer p_nd)
144 {
145  if (p_nd->m_type == i_node)
146  {
147  _GLIBCXX_DEBUG_ASSERT(p_nd->m_type == i_node);
148  for (typename inode::iterator it =
149  static_cast<inode_pointer>(p_nd)->begin();
150  it != static_cast<inode_pointer>(p_nd)->end();
151  ++it)
152  {
153  node_pointer p_child =* it;
154  clear_imp(p_child);
155  }
156  s_inode_allocator.deallocate(static_cast<inode_pointer>(p_nd), 1);
157  return;
158  }
159 
160  _GLIBCXX_DEBUG_ASSERT(p_nd->m_type == leaf_node);
161  static_cast<leaf_pointer>(p_nd)->~leaf();
162  s_leaf_allocator.deallocate(static_cast<leaf_pointer>(p_nd), 1);
163 }
164 
165 PB_DS_CLASS_T_DEC
166 inline typename PB_DS_CLASS_C_DEC::const_iterator
167 PB_DS_CLASS_C_DEC::
168 erase(const_iterator it)
169 {
170  PB_DS_ASSERT_VALID((*this))
171 
172  if (it == end())
173  return it;
174 
175  const_iterator ret_it = it;
176  ++ret_it;
177  _GLIBCXX_DEBUG_ASSERT(it.m_p_nd->m_type == leaf_node);
178  erase_leaf(static_cast<leaf_pointer>(it.m_p_nd));
179  PB_DS_ASSERT_VALID((*this))
180  return ret_it;
181 }
182 
183 #ifdef PB_DS_DATA_TRUE_INDICATOR
184 PB_DS_CLASS_T_DEC
185 inline typename PB_DS_CLASS_C_DEC::iterator
186 PB_DS_CLASS_C_DEC::
187 erase(iterator it)
188 {
189  PB_DS_ASSERT_VALID((*this))
190 
191  if (it == end())
192  return it;
193  iterator ret_it = it;
194  ++ret_it;
195  _GLIBCXX_DEBUG_ASSERT(it.m_p_nd->m_type == leaf_node);
196  erase_leaf(static_cast<leaf_pointer>(it.m_p_nd));
197  PB_DS_ASSERT_VALID((*this))
198  return ret_it;
199 }
200 #endif // #ifdef PB_DS_DATA_TRUE_INDICATOR
201 
202 PB_DS_CLASS_T_DEC
203 inline typename PB_DS_CLASS_C_DEC::const_reverse_iterator
204 PB_DS_CLASS_C_DEC::
205 erase(const_reverse_iterator it)
206 {
207  PB_DS_ASSERT_VALID((*this))
208 
209  if (it.m_p_nd == m_p_head)
210  return it;
211  const_reverse_iterator ret_it = it;
212  ++ret_it;
213 
214  _GLIBCXX_DEBUG_ASSERT(it.m_p_nd->m_type == leaf_node);
215  erase_leaf(static_cast<leaf_pointer>(it.m_p_nd));
216  PB_DS_ASSERT_VALID((*this))
217  return ret_it;
218 }
219 
220 #ifdef PB_DS_DATA_TRUE_INDICATOR
221 PB_DS_CLASS_T_DEC
222 inline typename PB_DS_CLASS_C_DEC::reverse_iterator
223 PB_DS_CLASS_C_DEC::
224 erase(reverse_iterator it)
225 {
226  PB_DS_ASSERT_VALID((*this))
227 
228  if (it.m_p_nd == m_p_head)
229  return it;
230  reverse_iterator ret_it = it;
231  ++ret_it;
232 
233  _GLIBCXX_DEBUG_ASSERT(it.m_p_nd->m_type == leaf_node);
234  erase_leaf(static_cast<leaf_pointer>(it.m_p_nd));
235  PB_DS_ASSERT_VALID((*this))
236  return ret_it;
237 }
238 #endif // #ifdef PB_DS_DATA_TRUE_INDICATOR
239 
240 PB_DS_CLASS_T_DEC
241 template<typename Pred>
242 inline typename PB_DS_CLASS_C_DEC::size_type
243 PB_DS_CLASS_C_DEC::
244 erase_if(Pred pred)
245 {
246  size_type num_ersd = 0;
247  PB_DS_ASSERT_VALID((*this))
248 
249  iterator it = begin();
250  while (it != end())
251  {
252  PB_DS_ASSERT_VALID((*this))
253  if (pred(*it))
254  {
255  ++num_ersd;
256  it = erase(it);
257  }
258  else
259  ++it;
260  }
261 
262  PB_DS_ASSERT_VALID((*this))
263  return num_ersd;
264 }
265 
266 PB_DS_CLASS_T_DEC
267 void
268 PB_DS_CLASS_C_DEC::
269 erase_leaf(leaf_pointer p_l)
270 {
271  update_min_max_for_erased_leaf(p_l);
272  if (p_l->m_p_parent->m_type == head_node)
273  {
274  _GLIBCXX_DEBUG_ASSERT(size() == 1);
275  clear();
276  return;
277  }
278 
279  _GLIBCXX_DEBUG_ASSERT(size() > 1);
280  _GLIBCXX_DEBUG_ASSERT(p_l->m_p_parent->m_type == i_node);
281 
282  inode_pointer p_parent = static_cast<inode_pointer>(p_l->m_p_parent);
283 
284  p_parent->remove_child(p_l);
285  erase_fixup(p_parent);
286  actual_erase_leaf(p_l);
287 }
288 
289 PB_DS_CLASS_T_DEC
290 void
291 PB_DS_CLASS_C_DEC::
292 update_min_max_for_erased_leaf(leaf_pointer p_l)
293 {
294  if (m_size == 1)
295  {
296  m_p_head->m_p_min = m_p_head;
297  m_p_head->m_p_max = m_p_head;
298  return;
299  }
300 
301  if (p_l == static_cast<leaf_const_pointer>(m_p_head->m_p_min))
302  {
303  iterator it(p_l);
304  ++it;
305  m_p_head->m_p_min = it.m_p_nd;
306  return;
307  }
308 
309  if (p_l == static_cast<leaf_const_pointer>(m_p_head->m_p_max))
310  {
311  iterator it(p_l);
312  --it;
313  m_p_head->m_p_max = it.m_p_nd;
314  }
315 }