@Test
@Ignore // FIXME started breaking 8/10
public void testRefreshNoisily() throws Exception {
final CountingCacheEntryFactory factory = new CountingCacheEntryFactory("value");
CountingCacheEventListener countingCacheEventListener = new CountingCacheEventListener();
CountingCacheEventListener.resetCounters();
cache.getCacheEventNotificationService().registerListener(countingCacheEventListener);
selfPopulatingCache = new SelfPopulatingCache(cache, factory);
// check initial conditions on counters
assertEquals(0, CountingCacheEventListener.getCacheElementsPut(cache).size());
assertEquals(0, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
Element e1 = selfPopulatingCache.get("key1");
Element e2 = selfPopulatingCache.get("key2");
assertEquals(2, factory.getCount());
assertEquals(2, CountingCacheEventListener.getCacheElementsPut(cache).size());
assertEquals(0, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
long lastUpdateTime1 = e1.getLastUpdateTime();
long lastUpdateTime2 = e2.getLastUpdateTime();
// wait a little so creation time to allow CPU clock to advance
Thread.sleep(100L);
// full refresh
selfPopulatingCache.refresh(false);
assertEquals(4, factory.getCount());
assertEquals(2, CountingCacheEventListener.getCacheElementsPut(cache).size());
assertEquals(2, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
e1 = selfPopulatingCache.get("key1");
e2 = selfPopulatingCache.get("key2");
assertEquals(4, factory.getCount());
assertEquals(2, CountingCacheEventListener.getCacheElementsPut(cache).size());
assertEquals(2, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
assertFalse(
"getLastUpdateTime() should not be the same (" + lastUpdateTime1 + ")",
lastUpdateTime1 == e1.getLastUpdateTime());
assertFalse(
"getLastUpdateTime() should not be the same (" + lastUpdateTime2 + ")",
lastUpdateTime2 == e2.getLastUpdateTime());
lastUpdateTime2 = e2.getLastUpdateTime();
// wait a little to allow CPU clock to advance
Thread.sleep(100L);
// single element refresh
e2 = selfPopulatingCache.refresh("key2", false);
assertEquals(5, factory.getCount());
assertEquals(2, CountingCacheEventListener.getCacheElementsPut(cache).size());
assertEquals(3, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
assertFalse(
"getLastUpdateTime() should not be the same (" + lastUpdateTime2 + ")",
lastUpdateTime2 == e2.getLastUpdateTime());
}
/**
* Expected: If multiple threads try to retrieve the same key from a SelfPopulatingCache at the
* same time, and that key is not yet in the cache, one thread obtains the lock for that key and
* uses the CacheEntryFactory to generate the cache entry and all other threads wait on the lock.
* Any and all threads which timeout while waiting for this lock should fail to acquire the lock
* for that key and throw an exception.
*
* <p>This thread tests for this by having several threads to a cache "get" for the same key,
* allowing one to acquire the lock and the others to wait. The one that acquires the lock and
* attempts to generate the cache entry for the key waits for a period of time long enough to
* allow all other threads to timeout waiting for the lock. Any thread that succeeds in acquiring
* the lock, including the first to do so, increment a counter when they begin creating the cache
* entry using the CacheEntryFactory. It is expected that this counter will only be "1" after all
* threads complete since all but the first to acquire it should timeout and throw exceptions.
*
* <p>We then test that a thread that comes along later increments the counter.
*/
@Test
public void testSelfPopulatingBlocksWithTimeoutSetNull() throws InterruptedException {
selfPopulatingCache =
new SelfPopulatingCache(
new Cache("TestCache", 50, false, false, 0, 0), new NullCachePopulator());
selfPopulatingCache.setTimeoutMillis(200);
manager.addCache(selfPopulatingCache);
CacheAccessorThread[] cacheAccessorThreads = new CacheAccessorThread[10];
for (int i = 0; i < cacheAccessorThreads.length; i++) {
cacheAccessorThreads[i] = new CacheAccessorThread(selfPopulatingCache, "key1");
cacheAccessorThreads[i].start();
// Do a slight delay here so that all the timeouts
// don't happen simultaneously - this is key
try {
Thread.sleep(20);
} catch (InterruptedException ignored) {
//
}
}
// All of the others should have timed out. The first thread will have returned null.
// This thread should be able to have a go, thus setting the count to 2
Thread.sleep(1000);
Thread lateThread = new CacheAccessorThread(selfPopulatingCache, "key1");
lateThread.start();
lateThread.join();
assertEquals(
"Too many cacheAccessorThreads tried to create selfPopulatingCache entry for key1",
2,
cacheEntryFactoryRequests);
}
/** Tests refreshing the entries. */
public void testRefresh() throws Exception {
final String value = "value";
final CountingCacheEntryFactory factory = new CountingCacheEntryFactory(value);
selfPopulatingCache = new SelfPopulatingCache(cache, factory);
// Check the value
assertSame(value, selfPopulatingCache.get("key").getObjectValue());
assertEquals(1, factory.getCount());
// Refresh
selfPopulatingCache.refresh();
assertEquals(2, factory.getCount());
// Check the value
assertSame(value, selfPopulatingCache.get("key").getObjectValue());
assertEquals(2, factory.getCount());
}
/** Tests fetching an entry. */
@Test
public void testFetch() throws Exception {
LOG.error(".");
// Lookup
final Element element = selfPopulatingCache.get("key");
assertEquals("value", element.getValue());
}
/**
* See {@link #testCacheEntryFactoryReturningElementMake} this test ensures the Refresh
* functionality works
*/
@Test
public void testCacheEntryFactoryReturningElementRefresh() throws Exception {
final long specialVersionNumber = 54321L;
final CacheEntryFactory elementReturningFactory =
new CacheEntryFactory() {
public Object createEntry(final Object key) throws Exception {
Element e = new Element(key, "V_" + key);
e.setVersion(specialVersionNumber);
return e;
}
};
selfPopulatingCache = new SelfPopulatingCache(cache, elementReturningFactory);
Element e = null;
e = selfPopulatingCache.get("key1");
assertEquals("V_key1", e.getValue());
assertEquals(specialVersionNumber, e.getVersion());
e = selfPopulatingCache.get("key2");
assertEquals("V_key2", e.getValue());
assertEquals(specialVersionNumber, e.getVersion());
assertEquals(2, selfPopulatingCache.getSize());
selfPopulatingCache.refresh();
e = selfPopulatingCache.get("key1");
assertEquals("V_key1", e.getValue());
assertEquals(specialVersionNumber, e.getVersion());
e = selfPopulatingCache.get("key2");
assertEquals("V_key2", e.getValue());
assertEquals(specialVersionNumber, e.getVersion());
assertEquals(2, selfPopulatingCache.getSize());
}
/**
* Tests that the current thread, which gets renamed when it enters a SelfPopulatingCache, comes
* out with its old name.
*/
public void testThreadNaming() throws Exception {
final String value = "value";
final CountingCacheEntryFactory factory = new CountingCacheEntryFactory(value);
selfPopulatingCache = new SelfPopulatingCache(cache, factory);
String originalThreadName = Thread.currentThread().getName();
// Check the value
selfPopulatingCache.get("key");
assertEquals(originalThreadName, Thread.currentThread().getName());
// Refresh
selfPopulatingCache.refresh();
assertEquals(originalThreadName, Thread.currentThread().getName());
// Check the value with null key
selfPopulatingCache.get(null);
assertEquals(originalThreadName, Thread.currentThread().getName());
}
/**
* Shows that a decorated cache has decorated behaviour for methods that override Cache methods,
* without requiring a cast.
*/
@Test
public void testDecoratorOverridesDefaultBehaviour() {
singletonManager = CacheManager.create();
Ehcache cache = singletonManager.getEhcache("sampleCache1");
Element element = cache.get("key");
// default behaviour for a missing key
assertNull(element);
// decorate and substitute
SelfPopulatingCache selfPopulatingCache =
new SelfPopulatingCache(cache, new CountingCacheEntryFactory("value"));
selfPopulatingCache.get("key");
singletonManager.replaceCacheWithDecoratedCache(cache, selfPopulatingCache);
Ehcache decoratedCache = singletonManager.getEhcache("sampleCache1");
assertNull(singletonManager.getCache("sampleCache1"));
Element element2 = cache.get("key");
assertEquals("value", element2.getObjectValue());
}
/** teardown */
@Override
@After
public void tearDown() throws Exception {
if (selfPopulatingCache != null) {
selfPopulatingCache.removeAll();
}
if (manager != null) {
manager.shutdown();
}
super.tearDown();
}
/** Tests that an entry is created once only. */
public void testCreateOnce() throws Exception {
final String value = "value";
final CountingCacheEntryFactory factory = new CountingCacheEntryFactory(value);
selfPopulatingCache = new SelfPopulatingCache(cache, factory);
// Fetch the value several times
for (int i = 0; i < 5; i++) {
assertSame(value, selfPopulatingCache.get("key").getObjectValue());
assertEquals(1, factory.getCount());
}
}
/** Tests refreshing the entries. */
@Test
public void testRefreshWithException() throws Exception {
final String value = "value";
final CountingCacheEntryFactory factory = new CountingCacheEntryFactory(value);
selfPopulatingCache = new SelfPopulatingCache(cache, factory);
// Check the value
String explodingKey = "explode";
assertSame(value, selfPopulatingCache.get(explodingKey).getObjectValue());
assertEquals(1, factory.getCount());
// Refresh
try {
selfPopulatingCache.refresh();
fail("This should have exploded!");
} catch (CacheException e) {
assertNotNull(e.getCause());
assertEquals(
e.getCause().getMessage() + " on refresh with key " + explodingKey, e.getMessage());
}
}
/** Tests when fetch fails. */
@Test
public void testFetchFail() throws Exception {
final Object value = new Object();
final Exception exception = new Exception("Failed.");
final AtomicBoolean throwException = new AtomicBoolean(true);
final CacheEntryFactory factory =
new CacheEntryFactory() {
public Object createEntry(final Object key) throws Exception {
if (throwException.get()) {
throw exception;
} else {
return value;
}
}
};
selfPopulatingCache = new SelfPopulatingCache(cache, factory);
// Lookup
try {
selfPopulatingCache.get("key");
fail();
} catch (final Exception e) {
Thread.sleep(20);
// Check the error
assertEquals("Could not fetch object for cache entry with key \"key\".", e.getMessage());
}
throwException.set(false);
selfPopulatingCache.setTimeoutMillis(1);
Element element = null;
try {
element = selfPopulatingCache.get("key");
} catch (LockTimeoutException e) {
fail("Key should not be locked anymore!");
}
assertThat(element, is(notNullValue()));
assertThat(element.getObjectValue(), is(value));
}
/**
* Tests discarding little used entries. <cache name="sampleIdlingExpiringCache"
* maxElementsInMemory="1" eternal="false" timeToIdleSeconds="2" timeToLiveSeconds="5"
* overflowToDisk="true" />
*/
public void testDiscardLittleUsed() throws Exception {
final CacheEntryFactory factory = new CountingCacheEntryFactory("value");
selfPopulatingCache = new SelfPopulatingCache(cache, factory);
selfPopulatingCache.get("key1");
selfPopulatingCache.get("key2");
assertEquals(2, selfPopulatingCache.getSize());
selfPopulatingCache.refresh();
assertEquals(2, selfPopulatingCache.getSize());
Thread.sleep(2020);
// Will be two, because counting expired elements
assertEquals(2, selfPopulatingCache.getSize());
// Check the cache
selfPopulatingCache.removeAll();
assertEquals(0, selfPopulatingCache.getSize());
}
/**
* See {@link #testCacheEntryFactoryReturningElementMake} this test ensures the Refresh
* functionality works
*/
@Test
public void testCacheEntryFactoryReturningElementBadKey() throws Exception {
final CacheEntryFactory elementReturningFactory =
new CacheEntryFactory() {
public Object createEntry(final Object key) throws Exception {
Object modifiedKey = key.toString() + "XX";
Element e = new Element(modifiedKey, "V_" + modifiedKey);
return e;
}
};
selfPopulatingCache = new SelfPopulatingCache(cache, elementReturningFactory);
try {
selfPopulatingCache.get("key");
fail("Should fail because key was changed");
} catch (final Exception e) {
Thread.sleep(20);
// Check the error
assertEquals("Could not fetch object for cache entry with key \"key\".", e.getMessage());
}
}
/** Tests when fetch fails. */
public void testFetchFail() throws Exception {
final Exception exception = new Exception("Failed.");
final CacheEntryFactory factory =
new CacheEntryFactory() {
public Object createEntry(final Object key) throws Exception {
throw exception;
}
};
selfPopulatingCache = new SelfPopulatingCache(cache, factory);
// Lookup
try {
selfPopulatingCache.get("key");
fail();
} catch (final Exception e) {
Thread.sleep(20);
// Check the error
assertEquals("Could not fetch object for cache entry \"key\".", e.getMessage());
}
}
@Test
public void testRefreshAbsentElement() throws Exception {
final IncrementingCacheEntryFactory factory = new IncrementingCacheEntryFactory();
selfPopulatingCache = new SelfPopulatingCache(cache, factory);
selfPopulatingCache.get("key1");
selfPopulatingCache.get("key2");
assertEquals(2, selfPopulatingCache.getSize());
assertEquals(2, factory.getCount());
// full refresh
selfPopulatingCache.refresh();
assertEquals(2, selfPopulatingCache.getSize());
assertEquals(4, factory.getCount());
// single element refresh which is not in the cache
Element e3 = selfPopulatingCache.refresh("key3");
assertEquals(3, selfPopulatingCache.getSize());
assertEquals(5, factory.getCount());
assertNotNull(e3);
assertEquals("key3", e3.getKey());
assertEquals(Integer.valueOf(5), e3.getValue());
}
@Test
public void testRefreshElement() throws Exception {
final IncrementingCacheEntryFactory factory = new IncrementingCacheEntryFactory();
selfPopulatingCache = new SelfPopulatingCache(cache, factory);
Element e1 = selfPopulatingCache.get("key1");
Element e2 = selfPopulatingCache.get("key2");
assertEquals(2, selfPopulatingCache.getSize());
assertEquals(2, factory.getCount());
assertEquals(Integer.valueOf(1), e1.getValue());
assertEquals(Integer.valueOf(2), e2.getValue());
// full refresh
selfPopulatingCache.refresh();
e1 = selfPopulatingCache.get("key1");
e2 = selfPopulatingCache.get("key2");
assertEquals(2, selfPopulatingCache.getSize());
assertEquals(4, factory.getCount());
// we cannot be sure which order key1 or key2 gets refreshed,
// as the implementation makes no guarantee over the sequence
// of the refresh; all we can be sure of is that between
// them key1&2 must have the values 3 & 4
int e1i = ((Integer) e1.getValue()).intValue();
int e2i = ((Integer) e2.getValue()).intValue();
assertTrue(((e1i == 3) && (e2i == 4)) || ((e1i == 4) && (e2i == 3)));
// single element refresh
selfPopulatingCache.get("key2");
Element e2r = selfPopulatingCache.refresh("key2");
assertEquals(2, selfPopulatingCache.getSize());
assertEquals(5, factory.getCount());
assertNotNull(e2r);
assertEquals("key2", e2r.getKey());
assertEquals(Integer.valueOf(5), e2r.getValue());
// additional element
Element e3 = selfPopulatingCache.get("key3");
assertEquals(3, selfPopulatingCache.getSize());
assertEquals(6, factory.getCount());
assertNotNull(e3);
assertEquals("key3", e3.getKey());
assertEquals(Integer.valueOf(6), e3.getValue());
// full refresh
selfPopulatingCache.refresh();
assertEquals(3, selfPopulatingCache.getSize());
assertEquals(9, factory.getCount());
}
/** teardown */
protected void tearDown() throws Exception {
selfPopulatingCache.removeAll();
manager.shutdown();
super.tearDown();
}
