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package org.webmacro.resource; |
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import java.lang.ref.SoftReference; |
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import java.util.concurrent.ConcurrentHashMap; |
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import java.util.concurrent.Executors; |
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import java.util.concurrent.ScheduledExecutorService; |
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import java.util.concurrent.ThreadFactory; |
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import java.util.concurrent.TimeUnit; |
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import org.slf4j.Logger; |
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import org.slf4j.LoggerFactory; |
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import org.webmacro.Broker; |
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import org.webmacro.InitException; |
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import org.webmacro.ResourceException; |
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import org.webmacro.util.Settings; |
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import org.webmacro.util.SubSettings; |
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26 | 409 | public class ReloadingCacheManager implements CacheManager { |
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|
28 | 2 | static Logger _log = LoggerFactory.getLogger(ReloadDelayDecorator.class); |
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private static final String NAME = "ReloadingCacheManager"; |
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|
32 | 12 | private final ConcurrentHashMap _cache = new ConcurrentHashMap(); |
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private int _cacheDurationMilliseconds; |
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private String _resourceType; |
35 | 12 | private boolean _reloadOnChange = true, _useSoftReferences = true; |
36 | 12 | private boolean _delayReloadChecks = false; |
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private long _checkForReloadDelay; |
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private ScheduledExecutorService _clockDaemon; |
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44 | 3084 | private abstract class MyCacheElement extends CacheElement implements Cloneable |
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{ |
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47 | 544 | private CacheReloadContext reloadContext = null; |
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public void setReloadContext (CacheReloadContext rc) |
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{ |
51 | 224 | if (_delayReloadChecks && rc != null) |
52 | 0 | this.reloadContext = new TimedReloadContext(rc, _checkForReloadDelay); |
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else |
54 | 224 | this.reloadContext = rc; |
55 | 224 | } |
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public abstract Object getObject (); |
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public abstract void setObject (Object o); |
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} |
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62 | 1088 | private final class SoftScmCacheElement extends MyCacheElement |
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{ |
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private SoftReference reference; |
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public Object getObject () |
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{ |
69 | 998 | return reference.get(); |
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} |
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public void setObject (Object o) |
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{ |
74 | 224 | reference = new SoftReference(o); |
75 | 224 | } |
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} |
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|
78 | 0 | private final class DirectScmCacheElement extends MyCacheElement |
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{ |
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private Object object; |
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public Object getObject () |
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{ |
85 | 0 | return object; |
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} |
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public void setObject (Object o) |
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{ |
90 | 0 | object = o; |
91 | 0 | } |
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} |
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public ReloadingCacheManager() |
95 | 12 | { |
96 | 12 | } |
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public void init (Broker b, Settings config, String resourceType) |
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throws InitException |
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{ |
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Settings ourSettings, defaultSettings; |
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|
103 | 12 | _clockDaemon = Executors.newSingleThreadScheduledExecutor(new ThreadFactory() { |
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public Thread newThread(Runnable runnable) { |
105 | 6 | _log.info("Creating new ClockDaemon thread"); |
106 | 6 | Thread t = new Thread(runnable); |
107 | 6 | t.setDaemon(true); |
108 | 6 | return t; |
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} |
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}); |
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|
112 | 12 | _resourceType = resourceType; |
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|
114 | 12 | ourSettings = new SubSettings(config, NAME + "." + _resourceType); |
115 | 12 | defaultSettings = new SubSettings(config, NAME + ".*"); |
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117 | 12 | _cacheDurationMilliseconds = |
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ourSettings.getIntegerSetting("ExpireTime", |
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defaultSettings.getIntegerSetting("ExpireTime", |
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config.getIntegerSetting("TemplateExpireTime", 0))); |
121 | 12 | _useSoftReferences = |
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(ourSettings.containsKey("UseSoftReferences")) |
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? ourSettings.getBooleanSetting("UseSoftReferences") |
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: ((defaultSettings.containsKey("UseSoftReferences")) |
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? defaultSettings.getBooleanSetting("UseSoftReferences") : true); |
126 | 12 | _reloadOnChange = |
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(ourSettings.containsKey("ReloadOnChange")) |
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? ourSettings.getBooleanSetting("ReloadOnChange") |
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: ((defaultSettings.containsKey("ReloadOnChange")) |
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? defaultSettings.getBooleanSetting("ReloadOnChange") : true); |
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|
132 | 12 | _checkForReloadDelay = |
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(ourSettings.getIntegerSetting("CheckForReloadDelay", |
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defaultSettings.getIntegerSetting("CheckForReloadDelay", -1))); |
135 | 12 | _delayReloadChecks = _checkForReloadDelay > 0; |
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|
137 | 12 | _log.info(NAME + "." + _resourceType + ": " |
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+ "; expireTime=" + _cacheDurationMilliseconds |
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+ "; reload=" + _reloadOnChange |
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+ "; softReference=" + _useSoftReferences |
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+ "; checkForReloadDelay=" + _checkForReloadDelay); |
142 | 12 | } |
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|
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private MyCacheElement newCacheElement() { |
145 | 544 | if (_useSoftReferences) |
146 | 544 | return new SoftScmCacheElement(); |
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else |
148 | 0 | return new DirectScmCacheElement(); |
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} |
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public void flush () |
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{ |
156 | 0 | _cache.clear(); |
157 | 0 | } |
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public void destroy () |
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{ |
164 | 0 | _cache.clear(); |
165 | 0 | _clockDaemon.shutdown(); |
166 | 0 | } |
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public boolean supportsReload () |
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{ |
170 | 12 | return _reloadOnChange; |
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} |
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private final void scheduleRemoval(final Object key) { |
174 | 224 | _clockDaemon.schedule( |
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new Runnable() |
176 | 224 | { |
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public void run () |
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{ |
179 | 185 | _cache.remove(key); |
180 | 185 | _log.debug("cache expired: " + key); |
181 | 185 | } |
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}, |
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_cacheDurationMilliseconds, |
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TimeUnit.MILLISECONDS); |
185 | 224 | } |
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public Object get (final Object query, ResourceLoader helper) |
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throws ResourceException |
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{ |
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MyCacheElement r; |
196 | 1542 | Object o = null; |
197 | 1542 | boolean reload = false; |
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|
199 | 1542 | r = (MyCacheElement) _cache.get(query); |
200 | 1542 | if (r != null) { |
201 | 998 | o = r.getObject(); |
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|
204 | 998 | if (o != null && r.reloadContext != null && _reloadOnChange) |
205 | 998 | reload = r.reloadContext.shouldReload(); |
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} |
207 | 1542 | if (o == null || reload) |
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{ |
209 | 544 | r = newCacheElement(); |
210 | 544 | o = helper.load(query, r); |
211 | 224 | if (o != null) |
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{ |
213 | 224 | r.setObject(o); |
214 | 224 | _cache.put(query, r); |
215 | 224 | _log.debug("cached: " + query + " for " + _cacheDurationMilliseconds); |
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try |
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{ |
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|
220 | 224 | if (_cacheDurationMilliseconds >= 0) |
221 | 224 | scheduleRemoval(query); |
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} |
223 | 0 | catch (Exception e) |
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{ |
225 | 0 | _log.error("CachingProvider caught an exception", e); |
226 | 224 | } |
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} |
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} |
229 | 1222 | return o; |
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} |
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public Object get (final Object query) |
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{ |
238 | 0 | MyCacheElement r = (MyCacheElement) _cache.get(query); |
239 | 0 | if (r != null) |
240 | 0 | return r.getObject(); |
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else |
242 | 0 | return null; |
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} |
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public void put (final Object query, Object resource) |
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{ |
250 | 0 | MyCacheElement r = newCacheElement(); |
251 | 0 | r.setObject(resource); |
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|
253 | 0 | _cache.put(query, r); |
254 | 0 | if (_cacheDurationMilliseconds >= 0) |
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{ |
256 | 0 | _log.debug("cached: " + query + " for " + _cacheDurationMilliseconds); |
257 | 0 | scheduleRemoval(query); |
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} |
259 | 0 | } |
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public void invalidate (final Object query) |
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{ |
264 | 0 | _cache.remove(query); |
265 | 0 | } |
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public String toString () |
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{ |
269 | 0 | return NAME + "(type = " + _resourceType + ")"; |
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} |
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} |