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* as indicated by the @author tags. See the copyright.txt file in the
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*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
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package org.infinispan.interceptors;
import java.util.concurrent.atomic.AtomicLong;
import org.infinispan.commands.read.GetKeyValueCommand;
import org.infinispan.commands.write.InvalidateCommand;
import org.infinispan.commands.write.PutKeyValueCommand;
import org.infinispan.commands.write.RemoveCommand;
import org.infinispan.commands.write.ReplaceCommand;
import org.infinispan.container.DataContainer;
import org.infinispan.container.EntryFactory;
import org.infinispan.container.entries.CacheEntry;
import org.infinispan.container.entries.InternalCacheEntry;
import org.infinispan.container.entries.MVCCEntry;
import org.infinispan.context.Flag;
import org.infinispan.context.InvocationContext;
import org.infinispan.factories.annotations.Inject;
import org.infinispan.factories.annotations.Start;
import org.infinispan.interceptors.base.JmxStatsCommandInterceptor;
import org.infinispan.jmx.annotations.MBean;
import org.infinispan.jmx.annotations.ManagedAttribute;
import org.infinispan.jmx.annotations.ManagedOperation;
import org.infinispan.loaders.CacheLoader;
import org.infinispan.loaders.CacheLoaderManager;
import org.infinispan.notifications.cachelistener.CacheNotifier;
import org.rhq.helpers.pluginAnnotations.agent.MeasurementType;
import org.rhq.helpers.pluginAnnotations.agent.Metric;
import org.rhq.helpers.pluginAnnotations.agent.Operation;
@MBean(objectName = "CacheLoader", description = "Component that handles loading entries from a CacheStore into memory.")
public class CacheLoaderInterceptor extends JmxStatsCommandInterceptor {
private final AtomicLong cacheLoads = new AtomicLong(0);
private final AtomicLong cacheMisses = new AtomicLong(0);
protected CacheLoaderManager clm;
protected CacheNotifier notifier;
protected CacheLoader loader;
private DataContainer dataContainer;
private EntryFactory entryFactory;
@Inject
protected void injectDependencies(CacheLoaderManager clm, DataContainer dataContainer, EntryFactory entryFactory, CacheNotifier notifier) {
this.clm = clm;
this.dataContainer = dataContainer;
this.notifier = notifier;
this.entryFactory = entryFactory;
}
@Start(priority = 15)
protected void startInterceptor() {
loader = clm.getCacheLoader();
}
@Override
public Object visitPutKeyValueCommand(InvocationContext ctx, PutKeyValueCommand command) throws Throwable {
Object key;
if ((key = command.getKey()) != null) {
loadIfNeeded(ctx, key);
}
return invokeNextInterceptor(ctx, command);
}
@Override
public Object visitGetKeyValueCommand(InvocationContext ctx, GetKeyValueCommand command) throws Throwable {
Object key;
if ((key = command.getKey()) != null) {
loadIfNeededAndUpdateStats(ctx, key);
}
return invokeNextInterceptor(ctx, command);
}
@Override
public Object visitInvalidateCommand(InvocationContext ctx, InvalidateCommand command) throws Throwable {
Object[] keys;
if ((keys = command.getKeys()) != null && keys.length > 0) {
for (Object key : command.getKeys()) {
loadIfNeeded(ctx, key);
}
}
return invokeNextInterceptor(ctx, command);
}
@Override
public Object visitRemoveCommand(InvocationContext ctx, RemoveCommand command) throws Throwable {
Object key;
if ((key = command.getKey()) != null) {
loadIfNeededAndUpdateStats(ctx, key);
}
return invokeNextInterceptor(ctx, command);
}
@Override
public Object visitReplaceCommand(InvocationContext ctx, ReplaceCommand command) throws Throwable {
Object key;
if ((key = command.getKey()) != null) {
loadIfNeededAndUpdateStats(ctx, key);
}
return invokeNextInterceptor(ctx, command);
}
private boolean loadIfNeeded(InvocationContext ctx, Object key) throws Throwable {
if (ctx.hasFlag(Flag.SKIP_CACHE_STORE) || ctx.hasFlag(Flag.SKIP_CACHE_LOAD)) {
return false; //skip operation
}
// first check if the container contains the key we need. Try and load this into the context.
CacheEntry e = entryFactory.wrapEntryForReading(ctx, key);
if (e == null || e.isNull()) {
// Obtain a temporary lock to verify the key is not being concurrently added
boolean keyLocked = entryFactory.acquireLock(ctx, key);
boolean unlockOnWayOut = false;
try {
// check again, in case there is a concurrent addition
if (dataContainer.containsKey(key)) {
log.trace("No need to load. Key exists in the data container.");
unlockOnWayOut = true;
return true;
}
} finally {
if (keyLocked && unlockOnWayOut) {
entryFactory.releaseLock(key);
}
}
// we *may* need to load this.
InternalCacheEntry loaded = loader.load(key);
if (loaded == null) {
if (log.isTraceEnabled()) {
log.trace("No need to load. Key doesn't exist in the loader.");
}
if (keyLocked) {
entryFactory.releaseLock(key);
}
return false;
}
// Reuse the lock and create a new entry for loading
MVCCEntry n = entryFactory.wrapEntryForWriting(ctx, key, true, false, keyLocked, false, true);
recordLoadedEntry(ctx, key, n, loaded);
return true;
} else {
return true;
}
}
/**
* This method records a loaded entry, performing the following steps:
* <ol>
* <li>Increments counters for reporting via JMX</li>
* <li>updates the 'entry' reference (an entry in the current thread's InvocationContext) with the contents of
* 'loadedEntry' (freshly loaded from the CacheStore) so that the loaded details will be flushed to the DataContainer
* when the call returns (in the LockingInterceptor, when locks are released)</li>
* <li>Notifies listeners</li>
* </ol>
* @param ctx the current invocation's context
* @param key key to record
* @param entry the appropriately locked entry in the caller's context
* @param loadedEntry the internal entry loaded from the cache store.
*/
private MVCCEntry recordLoadedEntry(InvocationContext ctx, Object key, MVCCEntry entry, InternalCacheEntry loadedEntry) throws Exception {
boolean entryExists = loadedEntry != null;
if (log.isTraceEnabled()) {
log.trace("Entry exists in loader? " + entryExists);
}
if (getStatisticsEnabled()) {
if (entryExists) {
cacheLoads.incrementAndGet();
} else {
cacheMisses.incrementAndGet();
}
}
if (entryExists) {
final Object value = loadedEntry.getValue();
// FIXME: There's no point to trigger the entryLoaded/Activated event twice.
sendNotification(key, value, true, ctx);
entry.setValue(value);
entry.setLifespan(loadedEntry.getLifespan());
entry.setMaxIdle(loadedEntry.getMaxIdle());
// TODO shouldn't we also be setting last used and created timestamps?
entry.setValid(true);
sendNotification(key, value, false, ctx);
}
return entry;
}
protected void sendNotification(Object key, Object value, boolean pre, InvocationContext ctx) {
notifier.notifyCacheEntryLoaded(key, value, pre, ctx);
}
private void loadIfNeededAndUpdateStats(InvocationContext ctx, Object key) throws Throwable {
boolean found = loadIfNeeded(ctx, key);
if (!found && getStatisticsEnabled()) {
cacheMisses.incrementAndGet();
}
}
@ManagedAttribute(description = "Number of entries loaded from cache store")
@Metric(displayName = "Number of cache store loads", measurementType = MeasurementType.TRENDSUP)
public long getCacheLoaderLoads() {
return cacheLoads.get();
}
@ManagedAttribute(description = "Number of entries that did not exist in cache store")
@Metric(displayName = "Number of cache store load misses", measurementType = MeasurementType.TRENDSUP)
public long getCacheLoaderMisses() {
return cacheMisses.get();
}
@Override
@ManagedOperation(description = "Resets statistics gathered by this component")
@Operation(displayName = "Reset Statistics")
public void resetStatistics() {
cacheLoads.set(0);
cacheMisses.set(0);
}
}