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1 package org.shiftone.cache.policy.fifo;
2
3
4
5 import org.shiftone.cache.util.*;
6 import org.shiftone.cache.util.reaper.ReapableCache;
7
8 import java.util.Map  ;
9
10
11
18 class FifoCache extends AbstractPolicyCache implements ReapableCache
19 {
20
21 private static final Log LOG = new Log(FifoCache.class);
22 private final Map map;
23 private final LinkedList fifo;
24
25 FifoCache(String name, long timeoutMilliSeconds, int maxSize)
26 {
27
28 super(name, timeoutMilliSeconds, maxSize);
29
30 this.map = MapFactory.createMap(maxSize);
31 this.fifo = new LinkedList();
32 }
33
34
35 protected CacheNode findNodeByKey(Object key)
36 {
37 return (FifoNode) map.get(key);
38 }
39
40
41 public int size()
42 {
43 return map.size();
44 }
45
46
47
50 protected final void revalueNode(CacheNode cacheNode) {}
51
52
53 protected void delete(CacheNode node)
54 {
55
56 FifoNode n = (FifoNode) node;
57
58 fifo.remove(n.fifoNode);
59 map.remove(n.key);
60 }
61
62
63 protected void removeLeastValuableNode()
64 {
65
66 LinkedListNode lln = null;
67 FifoNode node = null;
68
69 lln = fifo.peekLast();
70 node = (FifoNode) lln.getValue();
71
72 delete(node);
73 }
74
75
76 public void removeExpiredElements()
77 {
78
79 LinkedListNode lln = null;
80 CacheNode node;
81
82 while ((lln = fifo.peekLast()) != null)
83 {
84 node = (CacheNode) lln.getValue();
85
86 if (node.isExpired())
87 {
88 delete(node);
89 }
90 else
91 {
92
93 break;
95 }
96 }
97 }
98
99
100 protected CacheNode createNode(Object userKey, Object cacheObject)
101 {
102
103 FifoNode node = null;
104
105 node = new FifoNode();
106 node.key = userKey;
107 node.value = cacheObject;
108 node.fifoNode = fifo.addFirst(node); node.timeoutTime = System.currentTimeMillis() + getTimeoutMilliSeconds();
110
111 map.put(userKey, node);
112
113 return node;
114 }
115
116
117 String dumpFifoKeys()
118 {
119
120 String dump = null;
121 StringBuffer sb = new StringBuffer ();
122 LinkedListNode node = fifo.peekFirst();
123 FifoNode current = null;
124
125 while (node != null)
126 {
127 current = (FifoNode) node.getValue();
128
129 sb.append(current.key);
130
131 node = node.getNext();
132 }
133
134 dump = sb.toString();
135
136 return dump;
137 }
138 }
139 |
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