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1
21
22 package org.armedbear.j;
23
24 import java.util.Iterator  ;
25 import java.util.Vector ;
26
27 public final class DirectoryCache
28 {
29 private static final int timeout = 1800000;
31 private static DirectoryCache cache;
32
33 private Vector entries = new Vector ();
34
35 public static synchronized DirectoryCache getDirectoryCache()
36 {
37 if (cache == null) {
38 cache = new DirectoryCache();
39 IdleThread idleThread = IdleThread.getInstance();
40 if (idleThread != null)
41 idleThread.maybeAddTask(PruneDirectoryCacheTask.getInstance());
42 }
43 return cache;
44 }
45
46 public synchronized String getListing(File file)
47 {
48 String netPath = file.netPath();
49 for (int i = entries.size(); i-- > 0;) {
50 DirectoryCacheEntry entry = (DirectoryCacheEntry) entries.get(i);
51 if (entry.getFile().netPath().equals(netPath)) {
52 if (entry.getWhen() + timeout < System.currentTimeMillis()) {
53 Log.debug("removing cache entry for " + entry.getFile().netPath());
54 entries.remove(i);
55 return null;
56 }
57 return entry.getListing();
58 }
59 }
60 return null;
61 }
62
63 public synchronized void put(File file, String listing)
64 {
65 String netPath = file.netPath();
66 for (int i = entries.size(); i-- > 0;) {
67 DirectoryCacheEntry entry = (DirectoryCacheEntry) entries.get(i);
68 if (entry.getFile().netPath().equals(netPath)) {
69 entries.remove(i);
70 break;
71 }
72 }
73 if (listing != null && listing.length() > 0) {
74 entries.add(new DirectoryCacheEntry(file, listing,
75 System.currentTimeMillis()));
76 }
77 }
78
79 public synchronized void purge(String hostname)
80 {
81 for (int i = entries.size(); i-- > 0;) {
82 DirectoryCacheEntry entry = (DirectoryCacheEntry) entries.get(i);
83 if (entry.getFile().getHostName().equals(hostname)) {
84 Log.debug("removing cache entry for " + entry.getFile().netPath());
85 entries.remove(i);
86 }
87 }
88 }
89
90 public synchronized void purge(File file)
91 {
92 String netPath = file.netPath();
93 for (int i = entries.size(); i-- > 0;) {
94 DirectoryCacheEntry entry = (DirectoryCacheEntry) entries.get(i);
95 if (entry.getFile().netPath().equals(netPath)) {
96 Log.debug("removing cache entry for " + netPath);
97 entries.remove(i);
98 }
99 }
100 }
101
102 private static class PruneDirectoryCacheTask extends IdleThreadTask
103 {
104 private static PruneDirectoryCacheTask instance;
105
106 private long lastRun;
107
108 private PruneDirectoryCacheTask()
109 {
110 lastRun = System.currentTimeMillis();
111 setIdle(300000); setRunnable(runnable);
113 }
114
115 private static synchronized PruneDirectoryCacheTask getInstance()
116 {
117 if (instance == null)
118 instance = new PruneDirectoryCacheTask();
119 return instance;
120 }
121
122 private final Runnable runnable = new Runnable () {
123 public void run()
124 {
125 if (System.currentTimeMillis() - lastRun > 300000) {
127 long now = System.currentTimeMillis();
128 synchronized (cache) {
129 Iterator it = cache.entries.iterator();
130 while (it.hasNext()) {
131 DirectoryCacheEntry entry =
132 (DirectoryCacheEntry) it.next();
133 if (entry.getWhen() + timeout < now)
134 it.remove();
135 }
136 }
137 lastRun = now;
138 }
139 }
140 };
141 }
142 }
143 |
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