1 package org.lcsim.recon.tracking.trfutil;
2 import java.util.List;
3 import java.util.ArrayList;
4 import java.util.Iterator;
5
6 /**
7 * Maintains a list of pointers to RandomGenerator objects.
8 * The method record is called to record the state of each
9 * and set is called to reset the state of each to previously recorded
10 * values.
11 *
12 * @author Norman A. Graf
13 * @version 1.0
14 */
15 public class RandomRegistry
16 {
17 // attributes
18
19 // Known generators.
20 private List _gens = new ArrayList();
21
22 // Array of states for each generator.
23 private List _states = new ArrayList();
24
25 // methods
26
27 /**
28 * Hide copy constructor.
29 *
30 * @param rr
31 */
32 private RandomRegistry( RandomRegistry rr)
33 {
34 }
35
36 // methods
37
38 /**
39 * Constructor.
40 *
41 */
42 public RandomRegistry()
43 {
44 }
45
46 /**
47 * Register a generator.
48 *
49 * @param gen RandomGenerator to register.
50 */
51 public void addGenerator(RandomGenerator gen)
52 {
53 _gens.add( gen );
54 }
55
56 /**
57 * Record the states.
58 *
59 * @return A unique integer labeling the state.
60 */
61 public int record()
62 {
63
64 // Create a list of generators to record states.
65 int istate = _states.size();
66 _states.add( new ArrayList() );
67 List gens = (List) _states.get(istate);
68
69 // Loop over generators and fill list.
70 Iterator igen;
71 for ( igen=_gens.iterator(); igen.hasNext();)
72 gens.add( new RandomGenerator( (RandomGenerator) igen.next() ) );
73
74 return istate;
75
76 }
77
78 /**
79 * Return the number of registered generators.
80 *
81 * @return integer number of registered generators.
82 */
83 public int generatorCount()
84 {
85 return _gens.size();
86 }
87
88 /**
89 * Return the number of recorded states.
90 *
91 * @return integer number of recorded states.
92 */
93 public int stateCount()
94 {
95 return _states.size();
96 }
97
98 /**
99 * Reset the state.
100 *
101 * @param istate integer state to be reset.
102 * @return Return nonzero integer for error (e.g. unknown state index).
103 */
104 public int set(int istate)
105 {
106
107 // Check that the state exists.
108 if ( istate < 0 ) return 1;
109 if ( istate >= stateCount() ) return 2;
110
111 // Fetch the appropriate list of generators.
112 List oldgens = (List) _states.get(istate);
113
114 // Loop over generators and reset state.
115 // The recorded list may be shorter than the maintained list.
116 for ( int igen=0; igen<oldgens.size(); ++igen )
117 ( (RandomGenerator) _gens.get(igen)).setState( (RandomGenerator) oldgens.get(igen) );
118
119 return 0;
120
121 }
122
123 /**
124 * String representation of RandomRegistry.
125 *
126 * @return String representation of RandomRegistry.
127 */
128 public String toString()
129 {
130 String className = getClass().getName();
131 int lastDot = className.lastIndexOf('.');
132 if(lastDot!=-1)className = className.substring(lastDot+1);
133
134 StringBuffer sb = new StringBuffer(className+" with " + _gens.size() + " random generators: \n");
135 Iterator igen;
136 for ( igen=_gens.iterator(); igen.hasNext(); )
137 sb.append(igen.next()+"\n");
138 sb.append("\n"+stateCount() + " states recorded.");
139 return sb.toString();
140 }
141 }
142
143
144
145