/**
* Default Constructor
*
* @param cache the Terracotta clustered Cache to snapshot
* @param interval the interval to do the snapshots on
* @param doKeySnapshotOnDedicatedThread whether the snapshots have to be done on a dedicated
* thread
* @param rotatingWriter the RotatingSnapshotFile to write to
* @throws IllegalArgumentException if interval is less than or equal to zero
*/
KeySnapshotter(
final Ehcache cache,
final long interval,
final boolean doKeySnapshotOnDedicatedThread,
final RotatingSnapshotFile rotatingWriter)
throws IllegalArgumentException {
final Store store = new CacheStoreHelper((Cache) cache).getStore();
if (!(store instanceof TerracottaStore)) {
throw new IllegalArgumentException(
"Cache '"
+ cache.getName()
+ "' isn't backed by a "
+ TerracottaStore.class.getSimpleName()
+ " but uses a "
+ store.getClass().getName()
+ " instead");
}
if (interval <= 0) {
throw new IllegalArgumentException("Interval needs to be a positive & non-zero value");
}
if (rotatingWriter == null) {
throw new NullPointerException();
}
this.cacheName = cache.getName();
this.rotatingWriter = rotatingWriter;
this.tcStore = (TerracottaStore) store;
if (doKeySnapshotOnDedicatedThread) {
thread = new SnapShottingThread(this, interval, "KeySnapshotter for cache " + cacheName);
thread.start();
} else {
ScheduledExecutorService scheduledExecutorService = INSTANCES.get(cache.getCacheManager());
if (scheduledExecutorService == null) {
scheduledExecutorService = new ScheduledThreadPoolExecutor(POOL_SIZE);
final ScheduledExecutorService previous =
INSTANCES.putIfAbsent(cache.getCacheManager(), scheduledExecutorService);
if (previous != null) {
scheduledExecutorService.shutdownNow();
scheduledExecutorService = previous;
}
}
scheduledExecutorService.scheduleWithFixedDelay(this, interval, interval, TimeUnit.SECONDS);
thread = null;
}
}
/** {@inheritDoc} */
public void run() {
try {
INSTANCES.cleanUp();
rotatingWriter.writeAll(tcStore.getLocalKeys());
onSnapshot();
} catch (Throwable e) {
LOG.error("Couldn't snapshot local keySet for Cache {}", cacheName, e);
}
}
/**
* Accessor to all known cacheManagers (which are also bound to a ScheduledExecutorService)
*
* @return the collection of known CacheManagers
*/
static Collection<CacheManager> getKnownCacheManagers() {
return INSTANCES.keySet();
}