| 1 | |
package org.webmacro.resource; |
| 2 | |
|
| 3 | |
import java.lang.ref.SoftReference; |
| 4 | |
import java.util.concurrent.ConcurrentHashMap; |
| 5 | |
import java.util.concurrent.Executors; |
| 6 | |
import java.util.concurrent.ScheduledExecutorService; |
| 7 | |
import java.util.concurrent.ThreadFactory; |
| 8 | |
import java.util.concurrent.TimeUnit; |
| 9 | |
|
| 10 | |
import org.slf4j.Logger; |
| 11 | |
import org.slf4j.LoggerFactory; |
| 12 | |
|
| 13 | |
import org.webmacro.Broker; |
| 14 | |
import org.webmacro.InitException; |
| 15 | |
import org.webmacro.ResourceException; |
| 16 | |
import org.webmacro.util.Settings; |
| 17 | |
import org.webmacro.util.SubSettings; |
| 18 | |
|
| 19 | |
|
| 20 | |
|
| 21 | |
|
| 22 | |
|
| 23 | |
|
| 24 | |
|
| 25 | |
|
| 26 | 409 | public class ReloadingCacheManager implements CacheManager { |
| 27 | |
|
| 28 | 2 | static Logger _log = LoggerFactory.getLogger(ReloadDelayDecorator.class); |
| 29 | |
|
| 30 | |
private static final String NAME = "ReloadingCacheManager"; |
| 31 | |
|
| 32 | 12 | private final ConcurrentHashMap _cache = new ConcurrentHashMap(); |
| 33 | |
private int _cacheDurationMilliseconds; |
| 34 | |
private String _resourceType; |
| 35 | 12 | private boolean _reloadOnChange = true, _useSoftReferences = true; |
| 36 | 12 | private boolean _delayReloadChecks = false; |
| 37 | |
private long _checkForReloadDelay; |
| 38 | |
|
| 39 | |
|
| 40 | |
|
| 41 | |
private ScheduledExecutorService _clockDaemon; |
| 42 | |
|
| 43 | |
|
| 44 | 3084 | private abstract class MyCacheElement extends CacheElement implements Cloneable |
| 45 | |
{ |
| 46 | |
|
| 47 | 544 | private CacheReloadContext reloadContext = null; |
| 48 | |
|
| 49 | |
public void setReloadContext (CacheReloadContext rc) |
| 50 | |
{ |
| 51 | 224 | if (_delayReloadChecks && rc != null) |
| 52 | 0 | this.reloadContext = new TimedReloadContext(rc, _checkForReloadDelay); |
| 53 | |
else |
| 54 | 224 | this.reloadContext = rc; |
| 55 | 224 | } |
| 56 | |
|
| 57 | |
public abstract Object getObject (); |
| 58 | |
|
| 59 | |
public abstract void setObject (Object o); |
| 60 | |
} |
| 61 | |
|
| 62 | 1088 | private final class SoftScmCacheElement extends MyCacheElement |
| 63 | |
{ |
| 64 | |
|
| 65 | |
private SoftReference reference; |
| 66 | |
|
| 67 | |
public Object getObject () |
| 68 | |
{ |
| 69 | 998 | return reference.get(); |
| 70 | |
} |
| 71 | |
|
| 72 | |
public void setObject (Object o) |
| 73 | |
{ |
| 74 | 224 | reference = new SoftReference(o); |
| 75 | 224 | } |
| 76 | |
} |
| 77 | |
|
| 78 | 0 | private final class DirectScmCacheElement extends MyCacheElement |
| 79 | |
{ |
| 80 | |
|
| 81 | |
private Object object; |
| 82 | |
|
| 83 | |
public Object getObject () |
| 84 | |
{ |
| 85 | 0 | return object; |
| 86 | |
} |
| 87 | |
|
| 88 | |
public void setObject (Object o) |
| 89 | |
{ |
| 90 | 0 | object = o; |
| 91 | 0 | } |
| 92 | |
} |
| 93 | |
|
| 94 | |
public ReloadingCacheManager() |
| 95 | 12 | { |
| 96 | 12 | } |
| 97 | |
|
| 98 | |
public void init (Broker b, Settings config, String resourceType) |
| 99 | |
throws InitException |
| 100 | |
{ |
| 101 | |
Settings ourSettings, defaultSettings; |
| 102 | |
|
| 103 | 12 | _clockDaemon = Executors.newSingleThreadScheduledExecutor(new ThreadFactory() { |
| 104 | |
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; |
| 109 | |
} |
| 110 | |
}); |
| 111 | |
|
| 112 | 12 | _resourceType = resourceType; |
| 113 | |
|
| 114 | 12 | ourSettings = new SubSettings(config, NAME + "." + _resourceType); |
| 115 | 12 | defaultSettings = new SubSettings(config, NAME + ".*"); |
| 116 | |
|
| 117 | 12 | _cacheDurationMilliseconds = |
| 118 | |
ourSettings.getIntegerSetting("ExpireTime", |
| 119 | |
defaultSettings.getIntegerSetting("ExpireTime", |
| 120 | |
config.getIntegerSetting("TemplateExpireTime", 0))); |
| 121 | 12 | _useSoftReferences = |
| 122 | |
(ourSettings.containsKey("UseSoftReferences")) |
| 123 | |
? ourSettings.getBooleanSetting("UseSoftReferences") |
| 124 | |
: ((defaultSettings.containsKey("UseSoftReferences")) |
| 125 | |
? defaultSettings.getBooleanSetting("UseSoftReferences") : true); |
| 126 | 12 | _reloadOnChange = |
| 127 | |
(ourSettings.containsKey("ReloadOnChange")) |
| 128 | |
? ourSettings.getBooleanSetting("ReloadOnChange") |
| 129 | |
: ((defaultSettings.containsKey("ReloadOnChange")) |
| 130 | |
? defaultSettings.getBooleanSetting("ReloadOnChange") : true); |
| 131 | |
|
| 132 | 12 | _checkForReloadDelay = |
| 133 | |
(ourSettings.getIntegerSetting("CheckForReloadDelay", |
| 134 | |
defaultSettings.getIntegerSetting("CheckForReloadDelay", -1))); |
| 135 | 12 | _delayReloadChecks = _checkForReloadDelay > 0; |
| 136 | |
|
| 137 | 12 | _log.info(NAME + "." + _resourceType + ": " |
| 138 | |
+ "; expireTime=" + _cacheDurationMilliseconds |
| 139 | |
+ "; reload=" + _reloadOnChange |
| 140 | |
+ "; softReference=" + _useSoftReferences |
| 141 | |
+ "; checkForReloadDelay=" + _checkForReloadDelay); |
| 142 | 12 | } |
| 143 | |
|
| 144 | |
private MyCacheElement newCacheElement() { |
| 145 | 544 | if (_useSoftReferences) |
| 146 | 544 | return new SoftScmCacheElement(); |
| 147 | |
else |
| 148 | 0 | return new DirectScmCacheElement(); |
| 149 | |
} |
| 150 | |
|
| 151 | |
|
| 152 | |
|
| 153 | |
|
| 154 | |
public void flush () |
| 155 | |
{ |
| 156 | 0 | _cache.clear(); |
| 157 | 0 | } |
| 158 | |
|
| 159 | |
|
| 160 | |
|
| 161 | |
|
| 162 | |
public void destroy () |
| 163 | |
{ |
| 164 | 0 | _cache.clear(); |
| 165 | 0 | _clockDaemon.shutdown(); |
| 166 | 0 | } |
| 167 | |
|
| 168 | |
public boolean supportsReload () |
| 169 | |
{ |
| 170 | 12 | return _reloadOnChange; |
| 171 | |
} |
| 172 | |
|
| 173 | |
private final void scheduleRemoval(final Object key) { |
| 174 | 224 | _clockDaemon.schedule( |
| 175 | |
new Runnable() |
| 176 | 224 | { |
| 177 | |
public void run () |
| 178 | |
{ |
| 179 | 185 | _cache.remove(key); |
| 180 | 185 | _log.debug("cache expired: " + key); |
| 181 | 185 | } |
| 182 | |
}, |
| 183 | |
_cacheDurationMilliseconds, |
| 184 | |
TimeUnit.MILLISECONDS); |
| 185 | 224 | } |
| 186 | |
|
| 187 | |
|
| 188 | |
|
| 189 | |
|
| 190 | |
|
| 191 | |
|
| 192 | |
public Object get (final Object query, ResourceLoader helper) |
| 193 | |
throws ResourceException |
| 194 | |
{ |
| 195 | |
MyCacheElement r; |
| 196 | 1542 | Object o = null; |
| 197 | 1542 | boolean reload = false; |
| 198 | |
|
| 199 | 1542 | r = (MyCacheElement) _cache.get(query); |
| 200 | 1542 | if (r != null) { |
| 201 | 998 | o = r.getObject(); |
| 202 | |
|
| 203 | |
|
| 204 | 998 | if (o != null && r.reloadContext != null && _reloadOnChange) |
| 205 | 998 | reload = r.reloadContext.shouldReload(); |
| 206 | |
} |
| 207 | 1542 | if (o == null || reload) |
| 208 | |
{ |
| 209 | 544 | r = newCacheElement(); |
| 210 | 544 | o = helper.load(query, r); |
| 211 | 224 | if (o != null) |
| 212 | |
{ |
| 213 | 224 | r.setObject(o); |
| 214 | 224 | _cache.put(query, r); |
| 215 | 224 | _log.debug("cached: " + query + " for " + _cacheDurationMilliseconds); |
| 216 | |
try |
| 217 | |
{ |
| 218 | |
|
| 219 | |
|
| 220 | 224 | if (_cacheDurationMilliseconds >= 0) |
| 221 | 224 | scheduleRemoval(query); |
| 222 | |
} |
| 223 | 0 | catch (Exception e) |
| 224 | |
{ |
| 225 | 0 | _log.error("CachingProvider caught an exception", e); |
| 226 | 224 | } |
| 227 | |
} |
| 228 | |
} |
| 229 | 1222 | return o; |
| 230 | |
} |
| 231 | |
|
| 232 | |
|
| 233 | |
|
| 234 | |
|
| 235 | |
|
| 236 | |
public Object get (final Object query) |
| 237 | |
{ |
| 238 | 0 | MyCacheElement r = (MyCacheElement) _cache.get(query); |
| 239 | 0 | if (r != null) |
| 240 | 0 | return r.getObject(); |
| 241 | |
else |
| 242 | 0 | return null; |
| 243 | |
} |
| 244 | |
|
| 245 | |
|
| 246 | |
|
| 247 | |
|
| 248 | |
public void put (final Object query, Object resource) |
| 249 | |
{ |
| 250 | 0 | MyCacheElement r = newCacheElement(); |
| 251 | 0 | r.setObject(resource); |
| 252 | |
|
| 253 | 0 | _cache.put(query, r); |
| 254 | 0 | if (_cacheDurationMilliseconds >= 0) |
| 255 | |
{ |
| 256 | 0 | _log.debug("cached: " + query + " for " + _cacheDurationMilliseconds); |
| 257 | 0 | scheduleRemoval(query); |
| 258 | |
} |
| 259 | 0 | } |
| 260 | |
|
| 261 | |
|
| 262 | |
public void invalidate (final Object query) |
| 263 | |
{ |
| 264 | 0 | _cache.remove(query); |
| 265 | 0 | } |
| 266 | |
|
| 267 | |
public String toString () |
| 268 | |
{ |
| 269 | 0 | return NAME + "(type = " + _resourceType + ")"; |
| 270 | |
} |
| 271 | |
} |