1 package org.opentrafficsim.core.perception.collections;
2
3 import java.util.Collection;
4 import java.util.Collections;
5 import java.util.HashSet;
6 import java.util.Iterator;
7 import java.util.Set;
8
9 import org.djunits.value.vdouble.scalar.Time;
10 import org.opentrafficsim.core.perception.AbstractHistorical;
11 import org.opentrafficsim.core.perception.HistoryManager;
12 import org.opentrafficsim.core.perception.collections.AbstractHistoricalCollection.EventCollection;
13
14 /**
15 * Collection-valued historical state. The current collection is always maintained, and past states of the collection are
16 * obtained by applying the events between now and the requested time in reverse.<br>
17 * <br>
18 * This implementation is suitable for sets, as add and remove events to retrieve historical states are only created if indeed
19 * the underlying collection is changed. {@code Set} introduces no new methods relative to {@code Collection}.<br>
20 * <br>
21 * The {@code Iterator} returned by this class does not support the {@code remove()} method.
22 * <p>
23 * Copyright (c) 2013-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
24 * BSD-style license. See <a href="http://opentrafficsim.org/node/13">OpenTrafficSim License</a>.
25 * <p>
26 * @version $Revision$, $LastChangedDate$, by $Author$, initial version 1 jan. 2018 <br>
27 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
28 * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
29 * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
30 * @param <E> element type
31 * @param <C> collection type
32 */
33 public abstract class AbstractHistoricalCollection<E, C extends Collection<E>>
34 extends AbstractHistorical<E, EventCollection<E, C>> implements HistoricalCollection<E>
35 {
36
37 /** Current collection. */
38 private final C current;
39
40 /**
41 * Constructor.
42 * @param historyManager HistoryManager; history manager
43 * @param collection C; initial collection
44 */
45 protected AbstractHistoricalCollection(final HistoryManager historyManager, final C collection)
46 {
47 super(historyManager);
48 this.current = collection;
49 }
50
51 /**
52 * Returns the internal collection.
53 * @return C; internal collection
54 */
55 protected final C getCollection()
56 {
57 return this.current;
58 }
59
60 /**
61 * Fill collection with the current collection.
62 * @param collection C; collection to fill
63 * @return C; input collection filled
64 */
65 protected final C fill(final C collection)
66 {
67 collection.addAll(this.current);
68 return collection;
69 }
70
71 /**
72 * Fill collection with the collection at the given simulation time.
73 * @param time Time; time
74 * @param collection C; collection to fill
75 * @return C; input collection filled
76 */
77 protected final C fill(final Time time, final C collection)
78 {
79 // copy all current elements and decrement per event
80 collection.addAll(this.current);
81 for (EventCollection<E, C> event : getEvents(time))
82 {
83 event.restore(collection);
84 }
85 return collection;
86 }
87
88 // Altering Collection methods
89
90 /** {@inheritDoc} */
91 @Override
92 public boolean add(final E value)
93 {
94 boolean added = getCollection().add(value);
95 if (added)
96 {
97 addEvent(new AddEvent<>(now().si, value));
98 }
99 return added;
100 }
101
102 /** {@inheritDoc} */
103 @Override
104 public boolean addAll(final Collection<? extends E> c)
105 {
106 boolean changed = false;
107 for (E value : c)
108 {
109 changed |= add(value);
110 }
111 return changed;
112 }
113
114 /** {@inheritDoc} */
115 @Override
116 public void clear()
117 {
118 new HashSet<>(this.current).forEach(this::remove);
119 }
120
121 /** {@inheritDoc} */
122 @Override
123 @SuppressWarnings("unchecked")
124 public boolean remove(final Object value)
125 {
126 boolean removed = getCollection().remove(value);
127 if (removed)
128 {
129 addEvent(new RemoveEvent<>(now().si, (E) value)); // contains, so safe cast
130 }
131 return removed;
132 }
133
134 /** {@inheritDoc} */
135 @Override
136 public boolean removeAll(final Collection<?> c)
137 {
138 boolean changed = false;
139 for (Object value : c)
140 {
141 changed |= remove(value);
142 }
143 return changed;
144 }
145
146 /** {@inheritDoc} */
147 @Override
148 public boolean retainAll(final Collection<?> c)
149 {
150 boolean changed = false;
151 Set<E> values = new HashSet<>(this.current);
152 for (E value : values)
153 {
154 if (!c.contains(value))
155 {
156 changed |= remove(value);
157 }
158 }
159 return changed;
160 }
161
162 // Non-altering Collection methods
163
164 /** {@inheritDoc} */
165 @Override
166 public int size()
167 {
168 return this.current.size();
169 }
170
171 /** {@inheritDoc} */
172 @Override
173 public boolean isEmpty()
174 {
175 return this.current.isEmpty();
176 }
177
178 /** {@inheritDoc} */
179 @Override
180 public boolean contains(final Object o)
181 {
182 return this.current.contains(o);
183 }
184
185 /** {@inheritDoc} */
186 @Override
187 public Iterator<E> iterator()
188 {
189 return Collections.unmodifiableCollection(this.current).iterator();
190 }
191
192 /** {@inheritDoc} */
193 @Override
194 public Object[] toArray()
195 {
196 return this.current.toArray();
197 }
198
199 /** {@inheritDoc} */
200 @Override
201 public <T> T[] toArray(final T[] a)
202 {
203 return this.current.toArray(a);
204 }
205
206 /** {@inheritDoc} */
207 @Override
208 public boolean containsAll(final Collection<?> c)
209 {
210 return this.current.containsAll(c);
211 }
212
213 // Events
214
215 /**
216 * Abstract super class for events that add or remove a value from the collection.
217 * <p>
218 * Copyright (c) 2013-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
219 * <br>
220 * BSD-style license. See <a href="http://opentrafficsim.org/node/13">OpenTrafficSim License</a>.
221 * <p>
222 * @version $Revision$, $LastChangedDate$, by $Author$, initial version 1 jan. 2018 <br>
223 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
224 * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
225 * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
226 * @param <E> element type
227 * @param <C> collection type
228 */
229 public abstract static class EventCollection<E, C extends Collection<E>> extends AbstractHistorical.EventValue<E>
230 {
231
232 /**
233 * Constructor.
234 * @param time double; time of event
235 * @param value E; value of event
236 */
237 public EventCollection(final double time, final E value)
238 {
239 super(time, value);
240 }
241
242 /**
243 * Restores the collection to the state of before the event.
244 * @param collection C; collection to restore
245 */
246 public abstract void restore(C collection);
247
248 /** {@inheritDoc} */
249 @Override
250 public String toString()
251 {
252 return "EventCollection []";
253 }
254
255 }
256
257 /**
258 * Event for adding value to the collection.
259 * <p>
260 * Copyright (c) 2013-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
261 * <br>
262 * BSD-style license. See <a href="http://opentrafficsim.org/node/13">OpenTrafficSim License</a>.
263 * <p>
264 * @version $Revision$, $LastChangedDate$, by $Author$, initial version 1 jan. 2018 <br>
265 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
266 * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
267 * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
268 * @param <E> element type
269 * @param <C> collection type
270 */
271 public static class AddEvent<E, C extends Collection<E>> extends EventCollection<E, C>
272 {
273
274 /**
275 * Constructor.
276 * @param time double; time of event
277 * @param value E; value of event
278 */
279 public AddEvent(final double time, final E value)
280 {
281 super(time, value);
282 }
283
284 /** {@inheritDoc} */
285 @Override
286 public void restore(final C collection)
287 {
288 collection.remove(getValue()); // events are only created upon effective addition, so we can remove it
289 }
290
291 /** {@inheritDoc} */
292 @Override
293 public String toString()
294 {
295 return "AddEvent []";
296 }
297
298 }
299
300 /**
301 * Event for removing value from the collection.
302 * <p>
303 * Copyright (c) 2013-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
304 * <br>
305 * BSD-style license. See <a href="http://opentrafficsim.org/node/13">OpenTrafficSim License</a>.
306 * <p>
307 * @version $Revision$, $LastChangedDate$, by $Author$, initial version 1 jan. 2018 <br>
308 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
309 * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
310 * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
311 * @param <E> element type
312 * @param <C> collection type
313 */
314 public static class RemoveEvent<E, C extends Collection<E>> extends EventCollection<E, C>
315 {
316
317 /**
318 * Constructor.
319 * @param time double; time of event
320 * @param value E; value of event
321 */
322 public RemoveEvent(final double time, final E value)
323 {
324 super(time, value);
325 }
326
327 /** {@inheritDoc} */
328 @Override
329 public void restore(final C collection)
330 {
331 collection.add(getValue()); // events are only created upon effective removal, so we can add it
332 }
333
334 /** {@inheritDoc} */
335 @Override
336 public String toString()
337 {
338 return "RemoveEvent []";
339 }
340
341 }
342
343 }