1 package org.opentrafficsim.core.perception;
2
3 import java.util.Collections;
4 import java.util.Map;
5 import java.util.Set;
6 import java.util.WeakHashMap;
7
8 import org.djunits.value.vdouble.scalar.Duration;
9 import org.djunits.value.vdouble.scalar.Time;
10
11 import nl.tudelft.simulation.dsol.experiment.Replication;
12 import nl.tudelft.simulation.dsol.simtime.SimTimeDoubleUnit;
13 import nl.tudelft.simulation.dsol.simulators.DEVSSimulatorInterface;
14
15 /**
16 * History manager with automatic garbage collection by the java garbage collector using weak references to the
17 * {@code Historical}s.
18 * <p>
19 * Copyright (c) 2013-2018 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
20 * BSD-style license. See <a href="http://opentrafficsim.org/node/13">OpenTrafficSim License</a>.
21 * <p>
22 * @version $Revision$, $LastChangedDate$, by $Author$, initial version 18 jan. 2018 <br>
23 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
24 * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
25 * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
26 */
27 public abstract class HistoryManager
28 {
29
30 // HACK ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
31 // TODO remove this hack and obtain manager from somewhere else, OTSReplication?
32 /** Centrally stored manager. */
33 private static Map<Replication<Time, Duration, SimTimeDoubleUnit>, HistoryManagerDEVS> managers = new WeakHashMap<>();
34
35 /**
36 * Get central manager.
37 * @param simulator DEVSSimulatorInterface.TimeDoubleUnit; simulator
38 * @return HistoryManagerDEVS; central manager
39 */
40 public static HistoryManagerDEVS get(final DEVSSimulatorInterface.TimeDoubleUnit simulator)
41 {
42 HistoryManagerDEVS manager = managers.get(simulator.getReplication());
43 if (manager == null)
44 {
45 manager = new HistoryManagerDEVS(simulator, Duration.createSI(0.0), Duration.createSI(10.0));
46 managers.put(simulator.getReplication(), manager);
47 }
48 return manager;
49 }
50
51 /**
52 * Set central manager.
53 * @param manager HistoryManagerDEVS; manager
54 * @param simulator DEVSSimulatorInterface.TimeDoubleUnit; simulator
55 */
56 public static void set(final HistoryManagerDEVS manager, final DEVSSimulatorInterface.TimeDoubleUnit simulator)
57 {
58 managers.put(simulator.getReplication(), manager);
59 }
60
61 /**
62 * Clear central manager. If this is not done in batch simulations, this forms a memory leak.
63 * @param simulator DEVSSimulatorInterface.TimeDoubleUnit; simulator
64 */
65 public static void clear(final DEVSSimulatorInterface.TimeDoubleUnit simulator)
66 {
67 managers.remove(simulator.getReplication());
68 }
69 // END OF HACK /////////////////////////////////////////////////////////////////////////////////////////////////////////////
70
71 /** Set of all {@code Historical}s. */
72 // There's no WeakSet, but this is effectively the same. Iterating over this is safe, only alive objects are returned.
73 private final Set<HistoricalElement> historicals = Collections.newSetFromMap(new WeakHashMap<HistoricalElement, Boolean>());
74
75 /**
76 * Registers a historical.
77 * @param historical Historical; historical to register.
78 */
79 public void registerHistorical(final HistoricalElement historical)
80 {
81 if (historical != null)
82 {
83 this.historicals.add(historical);
84 }
85 }
86
87 /**
88 * Returns the historicals.
89 * @return the historicals
90 */
91 protected final Set<HistoricalElement> getHistoricals()
92 {
93 return this.historicals;
94 }
95
96 /**
97 * Returns the current simulation time. This is used by historicals to time-stamp state changes.
98 * @return Time; current simulation time.
99 */
100 abstract Time now();
101
102 /**
103 * Historical view for the history manager.
104 * <p>
105 * Copyright (c) 2013-2018 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
106 * <br>
107 * BSD-style license. See <a href="http://opentrafficsim.org/node/13">OpenTrafficSim License</a>.
108 * <p>
109 * @version $Revision$, $LastChangedDate$, by $Author$, initial version 1 feb. 2018 <br>
110 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
111 * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
112 * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
113 */
114 public interface HistoricalElement
115 {
116 /**
117 * Removes events that are no longer needed to guarantee the history time. This is invoked by the history manager.
118 * @param history Duration; history time to keep
119 */
120 void cleanUpHistory(Duration history);
121 }
122
123 /**
124 * Method that clears the entire memory at simulation end.
125 */
126 protected final void endOfSimulation()
127 {
128 for (HistoricalElement historical : this.historicals)
129 {
130 historical.cleanUpHistory(Duration.ZERO);
131 }
132 this.historicals.clear();
133 }
134
135 }