1 | /* -*- C++ -*- |
---|
2 | * |
---|
3 | * This file is a part of LEMON, a generic C++ optimization library |
---|
4 | * |
---|
5 | * Copyright (C) 2003-2006 |
---|
6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
---|
7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
---|
8 | * |
---|
9 | * Permission to use, modify and distribute this software is granted |
---|
10 | * provided that this copyright notice appears in all copies. For |
---|
11 | * precise terms see the accompanying LICENSE file. |
---|
12 | * |
---|
13 | * This software is provided "AS IS" with no warranty of any kind, |
---|
14 | * express or implied, and with no claim as to its suitability for any |
---|
15 | * purpose. |
---|
16 | * |
---|
17 | */ |
---|
18 | |
---|
19 | #ifndef LEMON_ALTERATION_OBSERVER_REGISTRY_H |
---|
20 | #define LEMON_ALTERATION_OBSERVER_REGISTRY_H |
---|
21 | |
---|
22 | #include <vector> |
---|
23 | #include <algorithm> |
---|
24 | |
---|
25 | ///\ingroup graphmapfactory |
---|
26 | ///\file |
---|
27 | ///\brief Observer registry for graph alteration observers. |
---|
28 | |
---|
29 | namespace lemon { |
---|
30 | |
---|
31 | /// \addtogroin graphmapfactory |
---|
32 | /// @{ |
---|
33 | |
---|
34 | /// \brief Registry class to register objects observes alterations in |
---|
35 | /// the graph. |
---|
36 | /// |
---|
37 | /// This class is a registry for the objects which observe the |
---|
38 | /// alterations in a container. The alteration observers can be attached |
---|
39 | /// to and detached from the registry. The observers have to inherit |
---|
40 | /// from the \ref AlterationNotifier::ObserverBase and override |
---|
41 | /// the virtual functions in that. |
---|
42 | /// |
---|
43 | /// The most important application of the alteration observing is the |
---|
44 | /// dynamic map implementation. |
---|
45 | /// |
---|
46 | /// \param _Item The item type what the observers are observing, usually |
---|
47 | /// edge or node. |
---|
48 | /// |
---|
49 | /// \author Balazs Dezso |
---|
50 | |
---|
51 | template <typename _Item> |
---|
52 | class AlterationNotifier { |
---|
53 | public: |
---|
54 | typedef _Item Item; |
---|
55 | |
---|
56 | /// ObserverBase is the base class for the observers. |
---|
57 | |
---|
58 | /// ObserverBase is the abstract base class for the observers. |
---|
59 | /// It will be notified about an item was inserted into or |
---|
60 | /// erased from the graph. |
---|
61 | /// |
---|
62 | /// The observer interface contains some pure virtual functions |
---|
63 | /// to override. The add() and erase() functions are |
---|
64 | /// to notify the oberver when one item is added or |
---|
65 | /// erased. |
---|
66 | /// |
---|
67 | /// The build() and clear() members are to notify the observer |
---|
68 | /// about the container is built from an empty container or |
---|
69 | /// is cleared to an empty container. |
---|
70 | /// |
---|
71 | /// \author Balazs Dezso |
---|
72 | |
---|
73 | class ObserverBase { |
---|
74 | protected: |
---|
75 | typedef AlterationNotifier Registry; |
---|
76 | |
---|
77 | friend class AlterationNotifier; |
---|
78 | |
---|
79 | /// \brief Default constructor. |
---|
80 | /// |
---|
81 | /// Default constructor for ObserverBase. |
---|
82 | /// |
---|
83 | ObserverBase() : registry(0) {} |
---|
84 | |
---|
85 | ObserverBase(const ObserverBase& copy) { |
---|
86 | if (copy.attached()) { |
---|
87 | copy.getRegistry()->attach(*this); |
---|
88 | } |
---|
89 | } |
---|
90 | |
---|
91 | virtual ~ObserverBase() {} |
---|
92 | |
---|
93 | /// \brief Attaches the observer into an AlterationNotifier. |
---|
94 | /// |
---|
95 | /// This member attaches the observer into an AlterationNotifier. |
---|
96 | /// |
---|
97 | void attach(AlterationNotifier& r) { |
---|
98 | registry = &r; |
---|
99 | registry->attach(*this); |
---|
100 | } |
---|
101 | |
---|
102 | /// \brief Detaches the observer into an AlterationNotifier. |
---|
103 | /// |
---|
104 | /// This member detaches the observer from an AlterationNotifier. |
---|
105 | /// |
---|
106 | void detach() { |
---|
107 | if (registry) { |
---|
108 | registry->detach(*this); |
---|
109 | } |
---|
110 | } |
---|
111 | |
---|
112 | |
---|
113 | /// Gives back a pointer to the registry what the map attached into. |
---|
114 | |
---|
115 | /// This function gives back a pointer to the registry what the map |
---|
116 | /// attached into. |
---|
117 | /// |
---|
118 | Registry* getRegistry() const { return const_cast<Registry*>(registry); } |
---|
119 | |
---|
120 | /// Gives back true when the observer is attached into a registry. |
---|
121 | bool attached() const { return registry != 0; } |
---|
122 | |
---|
123 | private: |
---|
124 | |
---|
125 | ObserverBase& operator=(const ObserverBase& copy); |
---|
126 | |
---|
127 | protected: |
---|
128 | |
---|
129 | Registry* registry; |
---|
130 | int registry_index; |
---|
131 | |
---|
132 | /// \brief The member function to notificate the observer about an |
---|
133 | /// item is added to the container. |
---|
134 | /// |
---|
135 | /// The add() member function notificates the observer about an item |
---|
136 | /// is added to the container. It have to be overrided in the |
---|
137 | /// subclasses. |
---|
138 | |
---|
139 | virtual void add(const Item&) = 0; |
---|
140 | |
---|
141 | /// \brief The member function to notificate the observer about |
---|
142 | /// more item is added to the container. |
---|
143 | /// |
---|
144 | /// The add() member function notificates the observer about more item |
---|
145 | /// is added to the container. It have to be overrided in the |
---|
146 | /// subclasses. |
---|
147 | |
---|
148 | virtual void add(const std::vector<Item>& items) { |
---|
149 | for (int i = 0; i < (int)items.size(); ++i) { |
---|
150 | add(items[i]); |
---|
151 | } |
---|
152 | } |
---|
153 | |
---|
154 | /// \brief The member function to notificate the observer about an |
---|
155 | /// item is erased from the container. |
---|
156 | /// |
---|
157 | /// The erase() member function notificates the observer about an |
---|
158 | /// item is erased from the container. It have to be overrided in |
---|
159 | /// the subclasses. |
---|
160 | |
---|
161 | virtual void erase(const Item&) = 0; |
---|
162 | |
---|
163 | /// \brief The member function to notificate the observer about |
---|
164 | /// more item is erased from the container. |
---|
165 | /// |
---|
166 | /// The erase() member function notificates the observer about more item |
---|
167 | /// is erased from the container. It have to be overrided in the |
---|
168 | /// subclasses. |
---|
169 | virtual void erase(const std::vector<Item>& items) { |
---|
170 | for (int i = 0; i < (int)items.size(); ++i) { |
---|
171 | erase(items[i]); |
---|
172 | } |
---|
173 | } |
---|
174 | |
---|
175 | /// \brief The member function to notificate the observer about the |
---|
176 | /// container is built. |
---|
177 | /// |
---|
178 | /// The build() member function notificates the observer about the |
---|
179 | /// container is built from an empty container. It have to be |
---|
180 | /// overrided in the subclasses. |
---|
181 | |
---|
182 | virtual void build() = 0; |
---|
183 | |
---|
184 | /// \brief The member function to notificate the observer about all |
---|
185 | /// items are erased from the container. |
---|
186 | /// |
---|
187 | /// The clear() member function notificates the observer about all |
---|
188 | /// items are erased from the container. It have to be overrided in |
---|
189 | /// the subclasses. |
---|
190 | |
---|
191 | virtual void clear() = 0; |
---|
192 | |
---|
193 | }; |
---|
194 | |
---|
195 | protected: |
---|
196 | |
---|
197 | |
---|
198 | typedef std::vector<ObserverBase*> Container; |
---|
199 | |
---|
200 | Container container; |
---|
201 | |
---|
202 | |
---|
203 | public: |
---|
204 | |
---|
205 | /// Default constructor. |
---|
206 | |
---|
207 | /// |
---|
208 | /// The default constructor of the AlterationNotifier. |
---|
209 | /// It creates an empty registry. |
---|
210 | AlterationNotifier() {} |
---|
211 | |
---|
212 | /// Copy Constructor of the AlterationNotifier. |
---|
213 | |
---|
214 | /// Copy constructor of the AlterationNotifier. |
---|
215 | /// It creates only an empty registry because the copiable |
---|
216 | /// registry's observers have to be registered still into that registry. |
---|
217 | AlterationNotifier(const AlterationNotifier&) {} |
---|
218 | |
---|
219 | /// Assign operator. |
---|
220 | |
---|
221 | /// Assign operator for the AlterationNotifier. |
---|
222 | /// It makes the notifier only empty because the copiable |
---|
223 | /// notifier's observers have to be registered still into that registry. |
---|
224 | AlterationNotifier& operator=(const AlterationNotifier&) { |
---|
225 | typename Container::iterator it; |
---|
226 | for (it = container.begin(); it != container.end(); ++it) { |
---|
227 | (*it)->registry = 0; |
---|
228 | } |
---|
229 | } |
---|
230 | |
---|
231 | /// Destructor. |
---|
232 | |
---|
233 | /// Destructor of the AlterationNotifier. |
---|
234 | /// |
---|
235 | ~AlterationNotifier() { |
---|
236 | typename Container::iterator it; |
---|
237 | for (it = container.begin(); it != container.end(); ++it) { |
---|
238 | (*it)->registry = 0; |
---|
239 | } |
---|
240 | } |
---|
241 | |
---|
242 | |
---|
243 | protected: |
---|
244 | |
---|
245 | void attach(ObserverBase& observer) { |
---|
246 | container.push_back(&observer); |
---|
247 | observer.registry = this; |
---|
248 | observer.registry_index = container.size()-1; |
---|
249 | } |
---|
250 | |
---|
251 | void detach(ObserverBase& base) { |
---|
252 | container.back()->registry_index = base.registry_index; |
---|
253 | container[base.registry_index] = container.back(); |
---|
254 | container.pop_back(); |
---|
255 | base.registry = 0; |
---|
256 | } |
---|
257 | |
---|
258 | public: |
---|
259 | |
---|
260 | /// \brief Notifies all the registered observers about an Item added to |
---|
261 | /// the container. |
---|
262 | /// |
---|
263 | /// It notifies all the registered observers about an Item added to |
---|
264 | /// the container. |
---|
265 | /// |
---|
266 | void add(const Item& item) { |
---|
267 | typename Container::iterator it; |
---|
268 | try { |
---|
269 | for (it = container.begin(); it != container.end(); ++it) { |
---|
270 | (*it)->add(item); |
---|
271 | } |
---|
272 | } catch (...) { |
---|
273 | typename Container::iterator jt; |
---|
274 | for (jt = container.begin(); jt != it; ++it) { |
---|
275 | (*it)->erase(item); |
---|
276 | } |
---|
277 | throw; |
---|
278 | } |
---|
279 | } |
---|
280 | |
---|
281 | /// \brief Notifies all the registered observers about more Item added to |
---|
282 | /// the container. |
---|
283 | /// |
---|
284 | /// It notifies all the registered observers about more Item added to |
---|
285 | /// the container. |
---|
286 | /// |
---|
287 | void add(const std::vector<Item>& items) { |
---|
288 | typename Container::iterator it; |
---|
289 | try { |
---|
290 | for (it = container.begin(); it != container.end(); ++it) { |
---|
291 | (*it)->add(items); |
---|
292 | } |
---|
293 | } catch (...) { |
---|
294 | typename Container::iterator jt; |
---|
295 | for (jt = container.begin(); jt != it; ++it) { |
---|
296 | (*it)->erase(items); |
---|
297 | } |
---|
298 | throw; |
---|
299 | } |
---|
300 | } |
---|
301 | |
---|
302 | /// \brief Notifies all the registered observers about an Item erased from |
---|
303 | /// the container. |
---|
304 | /// |
---|
305 | /// It notifies all the registered observers about an Item erased from |
---|
306 | /// the container. |
---|
307 | /// |
---|
308 | void erase(const Item& key) { |
---|
309 | typename Container::iterator it; |
---|
310 | for (it = container.begin(); it != container.end(); ++it) { |
---|
311 | (*it)->erase(key); |
---|
312 | } |
---|
313 | } |
---|
314 | |
---|
315 | /// \brief Notifies all the registered observers about more Item erased |
---|
316 | /// from the container. |
---|
317 | /// |
---|
318 | /// It notifies all the registered observers about more Item erased from |
---|
319 | /// the container. |
---|
320 | /// |
---|
321 | void erase(const std::vector<Item>& items) { |
---|
322 | typename Container::iterator it; |
---|
323 | for (it = container.begin(); it != container.end(); ++it) { |
---|
324 | (*it)->erase(items); |
---|
325 | } |
---|
326 | } |
---|
327 | |
---|
328 | /// \brief Notifies all the registered observers about the container is |
---|
329 | /// built. |
---|
330 | /// |
---|
331 | /// Notifies all the registered observers about the container is built |
---|
332 | /// from an empty container. |
---|
333 | void build() { |
---|
334 | typename Container::iterator it; |
---|
335 | try { |
---|
336 | for (it = container.begin(); it != container.end(); ++it) { |
---|
337 | (*it)->build(); |
---|
338 | } |
---|
339 | } catch (...) { |
---|
340 | typename Container::iterator jt; |
---|
341 | for (jt = container.begin(); jt != it; ++it) { |
---|
342 | (*it)->clear(); |
---|
343 | } |
---|
344 | throw; |
---|
345 | } |
---|
346 | } |
---|
347 | |
---|
348 | |
---|
349 | /// \brief Notifies all the registered observers about all Items are |
---|
350 | /// erased. |
---|
351 | /// |
---|
352 | /// Notifies all the registered observers about all Items are erased |
---|
353 | /// from the container. |
---|
354 | void clear() { |
---|
355 | typename Container::iterator it; |
---|
356 | for (it = container.begin(); it != container.end(); ++it) { |
---|
357 | (*it)->clear(); |
---|
358 | } |
---|
359 | } |
---|
360 | }; |
---|
361 | |
---|
362 | |
---|
363 | /// @} |
---|
364 | |
---|
365 | |
---|
366 | } |
---|
367 | |
---|
368 | #endif |
---|