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1 package org.shiftone.cache.policy.fifo;
2
3
4
5 import org.shiftone.cache.Cache;
6
7
8
12 public class RingFifoCache implements Cache
13 {
14
15 private final int maxSize;
16 private final int[] indexes;
17 private final Object  [] keys;
18 private final Object [] values;
19 private int nextIndexIndex = 0;
20
21 public RingFifoCache(int maxSize)
22 {
23
24 this.maxSize = maxSize;
25 indexes = new int[maxSize];
26 keys = new Object [maxSize];
27 values = new Object [maxSize];
28 }
29
30
31 private int getIndex(Object key)
32 {
33 return (key.hashCode() % maxSize);
34 }
35
36
37 public void addObject(Object userKey, Object cacheObject)
38 {
39
40 int index = getIndex(userKey);
41
42 indexes[nextIndexIndex] = index;
43 nextIndexIndex = (nextIndexIndex + 1) % maxSize;
44 keys[index] = userKey;
45 values[index] = cacheObject;
46 }
47
48
49 public Object getObject(Object key)
50 {
51
52 int index = getIndex(key);
53 Object k = keys[index];
54
55 if ((k != null) && (k.equals(key)))
56 {
57 return values[index];
58 }
59
60 return null;
61 }
62
63
64 public int size()
65 {
66 return 0;
67 }
68
69
70 public void remove(Object key) {}
71
72
73 public void clear() {}
74 }
75 |
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