/**
* Called immediately after an element has been put into the cache and the element already existed
* in the cache. This is thus an update.
*
* <p>The {@link net.sf.ehcache.Cache#put(net.sf.ehcache.Element)} method will block until this
* method returns.
*
* <p>Implementers may wish to have access to the Element's fields, including value, so the
* element is provided. Implementers should be careful not to modify the element. The effect of
* any modifications is undefined.
*
* @param cache the cache emitting the notification
* @param element the element which was just put into the cache.
*/
public final void notifyElementUpdated(final Ehcache cache, final Element element)
throws CacheException {
if (notAlive()) {
return;
}
if (!replicateUpdates) {
return;
}
if (replicateUpdatesViaCopy) {
if (!element.isSerializable()) {
if (LOG.isWarnEnabled()) {
LOG.warn(
"Object with key "
+ element.getObjectKey()
+ " is not Serializable and cannot be updated via copy.");
}
return;
}
addToReplicationQueue(new CacheEventMessage(EventMessage.PUT, cache, element, null));
} else {
if (!element.isKeySerializable()) {
if (LOG.isWarnEnabled()) {
LOG.warn(
"Object with key "
+ element.getObjectKey()
+ " does not have a Serializable key and cannot be replicated via invalidate.");
}
return;
}
addToReplicationQueue(
new CacheEventMessage(EventMessage.REMOVE, cache, null, element.getKey()));
}
}
/**
* Both CacheEntryFactory can return an Element rather than just a regular value this method test
* this, making a fresh Element otherwise. It also enforces the rule that the CacheEntryFactory
* must provide the same key (via equals() not necessarily same object) if it is returning an
* Element.
*
* @param key
* @param value
* @return the Element to be put back in the cache
* @throws CacheException for various illegal states which could be harmful
*/
protected static Element makeAndCheckElement(Object key, Object value) throws CacheException {
// check if null
if (value == null) {
return new Element(key, value);
}
// simply build a new element using the supplied key
if (!(value instanceof Element)) {
return new Element(key, value);
}
// It is already an element - perform sanity checks
Element element = (Element) value;
if ((element.getObjectKey() == null) && (key == null)) {
return element;
} else if (element.getObjectKey() == null) {
throw new CacheException("CacheEntryFactory returned an Element with a null key");
} else if (!element.getObjectKey().equals(key)) {
throw new CacheException(
"CacheEntryFactory returned an Element with a different key: "
+ element.getObjectKey()
+ " compared to the key that was requested: "
+ key);
} else {
return element;
}
}
/**
* Puts an element into the disk store.
*
* <p>This method is not synchronized. It is however threadsafe. It uses fine-grained
* synchronization on the spool.
*/
public final void put(final Element element) {
try {
checkActive();
// Spool the element
if (spoolAndExpiryThread.isAlive()) {
synchronized (spoolLock) {
spool.put(element.getObjectKey(), element);
}
} else {
LOG.error(
name
+ "Cache: Elements cannot be written to disk store because the"
+ " spool thread has died.");
synchronized (spoolLock) {
spool.clear();
}
}
} catch (Exception e) {
LOG.error(
name
+ "Cache: Could not write disk store element for "
+ element.getObjectKey()
+ ". Initial cause was "
+ e.getMessage(),
e);
}
}
/** Equals comparison with another element, based on the key. */
public final boolean equals(Object object) {
if (object == null || !(object instanceof Element)) {
return false;
}
Element element = (Element) object;
if (key == null || element.getObjectKey() == null) {
return false;
}
return key.equals(element.getObjectKey());
}
/** {@inheritDoc} */
public Element putIfAbsent(Element element) throws NullPointerException {
LOG.debug("cache {} putIfAbsent {}", cache.getName(), element);
XATransactionContext context = getOrCreateTransactionContext();
Element previous = getCurrentElement(element.getObjectKey(), context);
if (previous == null) {
Element oldElement = getQuietFromUnderlyingStore(element.getObjectKey());
Element elementForWrite = copyElementForWrite(element);
context.addCommand(new StorePutCommand(oldElement, elementForWrite), elementForWrite);
}
return copyElementForRead(previous);
}
/** {@inheritDoc} */
public Element removeElement(Element element, ElementValueComparator comparator)
throws NullPointerException {
LOG.debug("cache {} removeElement {}", cache.getName(), element);
XATransactionContext context = getOrCreateTransactionContext();
Element previous = getCurrentElement(element.getKey(), context);
Element elementForWrite = copyElementForWrite(element);
if (previous != null && comparator.equals(previous, elementForWrite)) {
Element oldElement = getQuietFromUnderlyingStore(element.getObjectKey());
context.addCommand(
new StoreRemoveCommand(element.getObjectKey(), oldElement), elementForWrite);
return copyElementForRead(previous);
}
return null;
}
/**
* Tests expiry notification is hooked up to searchInDiskStore. This test is not exact, because
* the expiry thread may also expire some.
*
* @throws InterruptedException
* @throws CacheException
*/
@Test
public void testExpiryViaDiskStoreCheckingOnGet()
throws InterruptedException, CacheException, IOException {
// Overflow 10 elements to disk store
for (int i = 0; i < 20; i++) {
Element element = new Element("" + i, new Date());
cache.put(element);
}
// Wait for expiry
Thread.sleep(5999);
// Trigger expiry
for (int i = 0; i < 20; i++) {
cache.get("" + i);
}
CountingCacheEventListener listener = getCountingCacheEventListener(cache);
List<CacheEvent> notifications = listener.getCacheElementsExpired();
for (int i = 0; i < notifications.size(); i++) {
Element element = notifications.get(i).getElement();
element.getObjectKey();
}
assertThat(notifications, hasSize(greaterThanOrEqualTo(10)));
}
/**
* Refresh a single element.
*
* @param element the Element to refresh
* @param backingCache the underlying {@link Ehcache}.
* @param quiet whether to use putQuiet or not, if true replication will not occur
* @return the refreshed Element
* @throws Exception
* @since 1.6.1
*/
protected Element refreshElement(final Element element, Ehcache backingCache, boolean quiet)
throws Exception {
Object key = element.getObjectKey();
if (LOG.isLoggable(Level.FINE)) {
LOG.fine(getName() + ": refreshing element with key " + key);
}
final Element replacementElement;
if (factory instanceof UpdatingCacheEntryFactory) {
// update the value of the cloned Element in place
replacementElement = element;
((UpdatingCacheEntryFactory) factory)
.updateEntryValue(key, replacementElement.getObjectValue());
// put the updated element back into the backingCache, without updating stats
// It is not usually necessary to do this. We do this in case the element expired
// or idles out of the backingCache. In that case we hold a reference to it but the
// backingCache no longer does.
} else {
final Object value = factory.createEntry(key);
replacementElement = makeAndCheckElement(key, value);
}
if (quiet) {
backingCache.putQuiet(replacementElement);
} else {
backingCache.put(replacementElement);
}
return replacementElement;
}
/**
* Removes expired elements.
*
* <p>Note that the DiskStore cannot efficiently expire based on TTI. It does it on TTL. However
* any gets out of the DiskStore are check for both before return.
*
* @noinspection SynchronizeOnNonFinalField
*/
public void expireElements() {
final long now = System.currentTimeMillis();
// Clean up the spool
synchronized (spoolLock) {
for (Iterator iterator = spool.values().iterator(); iterator.hasNext(); ) {
final Element element = (Element) iterator.next();
if (element.isExpired()) {
// An expired element
if (LOG.isDebugEnabled()) {
LOG.debug(name + "Cache: Removing expired spool element " + element.getObjectKey());
}
iterator.remove();
notifyExpiryListeners(element);
}
}
}
Element element = null;
RegisteredEventListeners listeners = cache.getCacheEventNotificationService();
synchronized (diskElements) {
// Clean up disk elements
for (Iterator iterator = diskElements.entrySet().iterator(); iterator.hasNext(); ) {
final Map.Entry entry = (Map.Entry) iterator.next();
final DiskElement diskElement = (DiskElement) entry.getValue();
if (now >= diskElement.expiryTime) {
// An expired element
if (LOG.isDebugEnabled()) {
LOG.debug(
name
+ "Cache: Removing expired spool element "
+ entry.getKey()
+ " from Disk Store");
}
iterator.remove();
// only load the element from the file if there is a listener interested in hearing about
// its expiration
if (listeners.hasCacheEventListeners()) {
try {
element = loadElementFromDiskElement(diskElement);
notifyExpiryListeners(element);
} catch (Exception exception) {
LOG.error(
name
+ "Cache: Could not remove disk store entry for "
+ entry.getKey()
+ ". Error was "
+ exception.getMessage(),
exception);
}
}
freeBlock(diskElement);
}
}
}
}
/** {@inheritDoc} */
public boolean put(Element element) throws CacheException {
LOG.debug("cache {} put {}", cache.getName(), element);
// this forces enlistment so the XA transaction timeout can be propagated to the XA resource
getOrCreateTransactionContext();
Element oldElement = getQuietFromUnderlyingStore(element.getObjectKey());
return internalPut(new StorePutCommand(oldElement, copyElementForWrite(element)));
}
@Test
public void testLFUEvictionFromDiskStore() throws IOException, InterruptedException {
Cache cache =
new Cache(
"testNonPersistent",
1,
MemoryStoreEvictionPolicy.LFU,
true,
null,
false,
2000,
1000,
false,
1,
null,
null,
10);
manager.addCache(cache);
Store store = cache.getStore();
Element element;
assertEquals(0, store.getSize());
for (int i = 0; i < 11; i++) {
element = new Element("key" + i, "value" + i);
cache.put(element);
if (i > 0) {
cache.get("key" + i);
cache.get("key" + i);
cache.get("key" + i);
cache.get("key" + i);
}
}
// allow to move through spool
Thread.sleep(220);
assertEquals(10, store.getOnDiskSize());
element = new Element("keyNew", "valueNew");
store.put(element);
// allow to get out of spool
Thread.sleep(220);
assertEquals(10, store.getOnDiskSize());
// check new element not evicted
assertNotNull(store.get(element.getObjectKey()));
// check evicted honours LFU policy
assertNull(store.get("key0"));
for (int i = 0; i < 2000; i++) {
store.put(new Element("" + i, new Date()));
}
// wait for spool to empty
waitLonger();
assertEquals(10, store.getOnDiskSize());
}
/**
* Saves the key to our fast access AtomicReferenceArray
*
* @param elementJustAdded the new element
*/
protected void saveKey(Element elementJustAdded) {
int index = incrementIndex();
Object key = keyArray.get(index);
Element oldElement = null;
if (key != null) {
oldElement = (Element) map.get(key);
}
if (oldElement != null) {
if (policy.compare(oldElement, elementJustAdded)) {
// new one will always be more desirable for eviction as no gets yet, unless no gets on old
// one.
// Consequence of this algorithm
keyArray.set(index, elementJustAdded.getObjectKey());
}
} else {
keyArray.set(index, elementJustAdded.getObjectKey());
}
}
private void evictIfRequired(final K key, final V value) {
if (maxEntriesLocalHeap == 0) {
return;
}
int evictions = MAX_EVICTIONS;
while (maxEntriesLocalHeap < mappingCount() && evictions-- > 0) {
final Element evictionCandidate = findEvictionCandidate(key, value);
if (evictionCandidate != null) {
remove(evictionCandidate.getObjectKey(), evictionCandidate, callback);
}
}
}
private void writeOrReplaceEntry(Object object) throws IOException {
Element element = (Element) object;
if (element == null) {
return;
}
final Serializable key = (Serializable) element.getObjectKey();
removeOldEntryIfAny(key);
if (maxElementsOnDisk > 0 && diskElements.size() >= maxElementsOnDisk) {
evictLfuDiskElement();
}
writeElement(element, key);
}
/**
* Removes the element chosen by the eviction policy
*
* @param elementJustAdded it is possible for this to be null
*/
protected void removeElementChosenByEvictionPolicy(Element elementJustAdded) {
if (LOG.isLoggable(Level.FINEST)) {
LOG.finest("Cache is full. Removing element ...");
}
Element element = findEvictionCandidate(elementJustAdded);
// this CAN happen rarely. Let the store get one bigger
if (element == null) {
LOG.info("Eviction selection miss. Selected element is null");
return;
}
// If the element is expired remove
if (element.isExpired()) {
remove(element.getObjectKey());
notifyExpiry(element);
return;
}
evict(element);
remove(element.getObjectKey());
}
/** {@inheritDoc} */
public boolean replace(Element old, Element element, ElementValueComparator comparator)
throws NullPointerException, IllegalArgumentException {
LOG.debug("cache {} replace2 {}", cache.getName(), element);
XATransactionContext context = getOrCreateTransactionContext();
Element previous = getCurrentElement(element.getKey(), context);
boolean replaced = false;
if (previous != null && comparator.equals(previous, copyElementForWrite(old))) {
Element oldElement = getQuietFromUnderlyingStore(element.getObjectKey());
Element elementForWrite = copyElementForWrite(element);
context.addCommand(new StorePutCommand(oldElement, elementForWrite), elementForWrite);
replaced = true;
}
return replaced;
}
/**
* Create a new write operation for a particular element and creation time
*
* @param element the element to write
* @param creationTime the creation time of the operation
*/
public WriteOperation(Element element, long creationTime) {
this.element =
new Element(
element.getObjectKey(),
element.getObjectValue(),
element.getVersion(),
element.getCreationTime(),
element.getLastAccessTime(),
element.getHitCount(),
false,
element.getTimeToLive(),
element.getTimeToIdle(),
element.getLastUpdateTime());
this.creationTime = creationTime;
}
/**
* Called immediately after an element has been removed. The remove method will block until this
* method returns.
*
* <p>This implementation queues the removal notification for in order replication to peers.
*
* @param cache the cache emitting the notification
* @param element just deleted
*/
public final void notifyElementRemoved(final Ehcache cache, final Element element)
throws CacheException {
if (!replicateRemovals) {
return;
}
if (!element.isKeySerializable()) {
if (LOG.isWarnEnabled()) {
LOG.warn(
"Key " + element.getObjectKey() + " is not Serializable and cannot be replicated.");
}
return;
}
addToReplicationQueue(
new CacheEventMessage(EventMessage.REMOVE, cache, null, element.getKey()));
}
@Override
public void after(Object target, Object result, Throwable throwable, Object[] args) {
if (isDebug) {
logger.afterInterceptor(target, args, result, throwable);
}
try {
((CacheNameAccessor) target)._$PINPOINT$_setCacheName(DEFAULT_FRONTCACHE_NAME);
if (args[0] instanceof Element) {
Element element = (Element) args[0];
((CacheKeyAccessor) target)._$PINPOINT$_setCacheKey(element.getObjectKey());
}
} catch (Exception e) {
logger.error("failed to add metadata: {}", e);
}
}
private void notifyEvictionListeners(DiskElement diskElement) {
RegisteredEventListeners listeners = cache.getCacheEventNotificationService();
// only load the element from the file if there is a listener interested in hearing about its
// expiration
if (listeners.hasCacheEventListeners()) {
Element element = null;
try {
element = loadElementFromDiskElement(diskElement);
cache.getCacheEventNotificationService().notifyElementEvicted(element, false);
} catch (Exception exception) {
LOG.error(
name
+ "Cache: Could not notify disk store eviction of "
+ element.getObjectKey()
+ ". Error was "
+ exception.getMessage(),
exception);
}
}
}
/**
* Spools all elements to disk, in preparation for shutdown.
*
* <p>Relies on being called from a synchronized method
*
* <p>This revised implementation is a little slower but avoids using increased memory during the
* method.
*/
protected final void spoolAllToDisk() {
Object[] keys = getKeyArray();
for (int i = 0; i < keys.length; i++) {
Element element = (Element) map.get(keys[i]);
if (element != null) {
if (!element.isSerializable()) {
if (LOG.isLoggable(Level.FINE)) {
LOG.fine(
"Object with key "
+ element.getObjectKey()
+ " is not Serializable and is not being overflowed to disk.");
}
} else {
spoolToDisk(element);
// Don't notify listeners. They are not being removed from the cache, only a store
remove(keys[i]);
}
}
}
}
/**
* {@inheritDoc}
*
* <p>This implementation queues the put notification for in-order replication to peers.
*
* @param cache the cache emitting the notification
* @param element the element which was just put into the cache.
*/
public final void notifyElementPut(final Ehcache cache, final Element element)
throws CacheException {
if (notAlive()) {
return;
}
if (!replicatePuts) {
return;
}
if (!element.isSerializable()) {
if (LOG.isWarnEnabled()) {
LOG.warn(
"Object with key "
+ element.getObjectKey()
+ " is not Serializable and cannot be replicated");
}
return;
}
addToReplicationQueue(new CacheEventMessage(EventMessage.PUT, cache, element, null));
}
/**
* Evict the <code>Element</code>.
*
* <p>Evict means that the <code>Element</code> is:
*
* <ul>
* <li>if, the store is diskPersistent, the <code>Element</code> is spooled to the DiskStore
* <li>if not, the <code>Element</code> is removed.
* </ul>
*
* @param element the <code>Element</code> to be evicted.
*/
protected final void evict(Element element) throws CacheException {
boolean spooled = false;
if (cache.getCacheConfiguration().isOverflowToDisk()) {
if (!element.isSerializable()) {
if (LOG.isLoggable(Level.FINE)) {
LOG.log(
Level.FINE,
new StringBuffer("Object with key ")
.append(element.getObjectKey())
.append(" is not Serializable and cannot be overflowed to disk")
.toString());
}
} else {
spoolToDisk(element);
spooled = true;
}
}
if (!spooled) {
cache.getCacheEventNotificationService().notifyElementEvicted(element, false);
}
}
/** {@inheritDoc} */
public Object getKey() {
return element.getObjectKey();
}
private void possiblyTriggerRefresh(Element elem, long timeToRefreshMillis) {
if (checkForRefresh(elem, System.currentTimeMillis(), timeToRefreshMillis)) {
// now add the key to the queue. smallest overhead we could get.
refreshWorkQueue.offer(elem.getObjectKey());
}
}
/**
* Puts the element in the DiskStore. Should only be called if overflowToDisk is true
*
* <p>Relies on being called from a synchronized method
*
* @param element The Element
*/
protected void spoolToDisk(Element element) {
diskStore.put(element);
if (LOG.isLoggable(Level.FINE)) {
LOG.fine(cache.getName() + "Cache: spool to disk done for: " + element.getObjectKey());
}
}
@Test
public void testTimeToLive() {
Assert.assertEquals(_VALUE_1, _ehcachePortalCache.get(_KEY_1));
Assert.assertNull(_ehcachePortalCache.get(_KEY_2));
// Put
int timeToLive = 600;
_ehcachePortalCache.put(_KEY_2, _VALUE_2, timeToLive);
Ehcache ehcache = _ehcachePortalCache.ehcache;
Element element = ehcache.get(_KEY_2);
Assert.assertEquals(_KEY_2, element.getObjectKey());
Assert.assertEquals(_VALUE_2, element.getObjectValue());
Assert.assertEquals(timeToLive, element.getTimeToLive());
_defaultCacheListener.assertPut(_KEY_2, _VALUE_2, timeToLive);
_defaultCacheListener.reset();
// Put if absent
ehcache.removeElement(element);
_ehcachePortalCache.putIfAbsent(_KEY_2, _VALUE_2, timeToLive);
element = ehcache.get(_KEY_2);
Assert.assertEquals(_KEY_2, element.getObjectKey());
Assert.assertEquals(_VALUE_2, element.getObjectValue());
Assert.assertEquals(timeToLive, element.getTimeToLive());
_defaultCacheListener.assertPut(_KEY_2, _VALUE_2, timeToLive);
_defaultCacheListener.reset();
// Replace 1
ehcache.removeElement(element);
_ehcachePortalCache.replace(_KEY_1, _VALUE_2, timeToLive);
element = ehcache.get(_KEY_1);
Assert.assertEquals(_KEY_1, element.getObjectKey());
Assert.assertEquals(_VALUE_2, element.getObjectValue());
Assert.assertEquals(timeToLive, element.getTimeToLive());
_defaultCacheListener.assertUpdated(_KEY_1, _VALUE_2, timeToLive);
_defaultCacheListener.reset();
// Replace 2
ehcache.removeElement(element);
_ehcachePortalCache.put(_KEY_1, _VALUE_1);
Assert.assertEquals(_VALUE_1, _ehcachePortalCache.get(_KEY_1));
Assert.assertNull(_ehcachePortalCache.get(_KEY_2));
_ehcachePortalCache.replace(_KEY_1, _VALUE_1, _VALUE_2, timeToLive);
element = ehcache.get(_KEY_1);
Assert.assertEquals(_KEY_1, element.getObjectKey());
Assert.assertEquals(_VALUE_2, element.getObjectValue());
Assert.assertEquals(timeToLive, element.getTimeToLive());
_defaultCacheListener.assertPut(_KEY_1, _VALUE_1);
_defaultCacheListener.assertUpdated(_KEY_1, _VALUE_2, timeToLive);
_defaultCacheListener.reset();
}
/**
* Puts an item in the cache. Note that this automatically results in an eviction if the store is
* full.
*
* @param element the element to add
*/
public final void put(Element element) throws CacheException {
if (element != null) {
map.put(element.getObjectKey(), element);
doPut(element);
}
}
