@GuardedBy("this") ReferenceEntry<K, V> getNextEvictable() { for (ReferenceEntry<K, V> e : accessQueue) { int weight = e.getValueReference().getWeight(); if (weight > 0) { return e; } } throw new AssertionError(); }
@GuardedBy("this") void removeCollectedEntry(ReferenceEntry<K, V> entry) { enqueueNotification( entry.getKey(), entry.getHash(), entry.getValueReference().get(), entry.getValueReference().getWeight(), RemovalCause.COLLECTED); writeQueue.remove(entry); accessQueue.remove(entry); }
@VisibleForTesting @GuardedBy("this") boolean removeEntry(ReferenceEntry<K, V> entry, int hash, RemovalCause cause) { int newCount = this.count - 1; AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table; int index = hash & (table.length() - 1); ReferenceEntry<K, V> first = table.get(index); for (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) { if (e == entry) { ++modCount; ReferenceEntry<K, V> newFirst = removeValueFromChain( first, e, e.getKey(), hash, e.getValueReference().get(), e.getValueReference(), cause); newCount = this.count - 1; table.set(index, newFirst); this.count = newCount; // write-volatile return true; } } return false; }
/** Sets a new value of an entry. Adds newly created entries at the end of the access queue. */ @GuardedBy("this") void setValue(ReferenceEntry<K, V> entry, K key, V value, long now) { ValueReference<K, V> previous = entry.getValueReference(); int weight = map.weigher.weigh(key, value); checkState(weight >= 0, "Weights must be non-negative"); ValueReference<K, V> valueReference = map.valueStrength.referenceValue(this, entry, value, weight); entry.setValueReference(valueReference); recordWrite(entry, weight, now); previous.notifyNewValue(value); }
static <K, V> Map<K, V> segmentTable(Segment<K, V> segment) { AtomicReferenceArray<? extends ReferenceEntry<K, V>> table = segment.table; Map<K, V> map = Maps.newLinkedHashMap(); for (int i = 0; i < table.length(); i++) { for (ReferenceEntry<K, V> entry = table.get(i); entry != null; entry = entry.getNext()) { K key = entry.getKey(); V value = entry.getValueReference().get(); if (key != null && value != null) { assertNull(map.put(key, value)); } } } return map; }
boolean containsKey(Object key, int hash) { try { if (count != 0) { // read-volatile long now = map.ticker.read(); ReferenceEntry<K, V> e = getLiveEntry(key, hash, now); if (e == null) { return false; } return e.getValueReference().get() != null; } return false; } finally { postReadCleanup(); } }
V scheduleRefresh( ReferenceEntry<K, V> entry, K key, int hash, V oldValue, long now, CacheLoader<? super K, V> loader) { if (map.refreshes() && (now - entry.getWriteTime() > map.refreshNanos) && !entry.getValueReference().isLoading()) { V newValue = refresh(key, hash, loader, true); if (newValue != null) { return newValue; } } return oldValue; }
/** * Gets the value from an entry. Returns null if the entry is invalid, partially-collected, * loading, or expired. Unlike {@link Segment#getLiveValue} this method does not attempt to * cleanup stale entries. As such it should only be called outside of a segment context, such as * during iteration. */ @Nullable V getLiveValue(ReferenceEntry<K, V> entry, long now) { if (entry.getKey() == null) { return null; } V value = entry.getValueReference().get(); if (value == null) { return null; } if (isExpired(entry, now)) { return null; } return value; }
private static <K, V> void assertSameEntries( List<ReferenceEntry<K, V>> expectedEntries, List<ReferenceEntry<K, V>> actualEntries) { int size = expectedEntries.size(); assertEquals(size, actualEntries.size()); for (int i = 0; i < size; i++) { ReferenceEntry<K, V> expectedEntry = expectedEntries.get(i); ReferenceEntry<K, V> actualEntry = actualEntries.get(i); assertSame(expectedEntry.getKey(), actualEntry.getKey()); assertSame(expectedEntry.getValueReference().get(), actualEntry.getValueReference().get()); } }
/** * Poke into the Cache internals to simulate garbage collection of the value associated with the * given key. This assumes that the associated entry is a WeakValueReference or a * SoftValueReference (and not a LoadingValueReference), and throws an IllegalStateException if * that assumption does not hold. */ @SuppressWarnings("unchecked") // the instanceof check and the cast generate this warning static <K, V> void simulateValueReclamation(Cache<K, V> cache, K key) { ReferenceEntry<K, V> entry = getReferenceEntry(cache, key); if (entry != null) { ValueReference<K, V> valueRef = entry.getValueReference(); // fail on strong/computing refs Preconditions.checkState(valueRef instanceof Reference); Reference<V> ref = (Reference<V>) valueRef; if (ref != null) { ref.clear(); } } }
/** Sets a new value of an entry. Adds newly created entries at the end of the access queue. */ @GuardedBy("this") void setValue(ReferenceEntry<K, V> entry, K key, V value, long now) { ValueReference<K, V> previous = entry.getValueReference(); int weight = map.weigher.weigh(key, value); checkState(weight >= 0, "Weights must be non-negative"); ValueReference<K, V> valueReference = map.valueStrength.referenceValue(this, entry, value, weight); entry.setValueReference(valueReference); recordWrite(entry, weight, now); previous.notifyNewValue(value); }
/** * Performs eviction if the segment is over capacity. Avoids flushing the entire cache if the * newest entry exceeds the maximum weight all on its own. * * @param newest the most recently added entry */ @GuardedBy("this") void evictEntries(ReferenceEntry<K, V> newest) { if (!map.evictsBySize()) { return; } drainRecencyQueue(); // If the newest entry by itself is too heavy for the segment, don't bother evicting // anything else, just that if (newest.getValueReference().getWeight() > maxSegmentWeight) { if (!removeEntry(newest, newest.getHash(), RemovalCause.SIZE)) { throw new AssertionError(); } } while (totalWeight > maxSegmentWeight) { ReferenceEntry<K, V> e = getNextEvictable(); if (!removeEntry(e, e.getHash(), RemovalCause.SIZE)) { throw new AssertionError(); } } }
/** * Gets the value from an entry. Returns null if the entry is invalid, partially-collected, * loading, or expired. */ V getLiveValue(ReferenceEntry<K, V> entry, long now) { if (entry.getKey() == null) { tryDrainReferenceQueues(); return null; } V value = entry.getValueReference().get(); if (value == null) { tryDrainReferenceQueues(); return null; } if (map.isExpired(entry, now)) { tryExpireEntries(now); return null; } return value; }
/** * Copies {@code original} into a new entry chained to {@code newNext}. Returns the new entry, * or {@code null} if {@code original} was already garbage collected. */ @GuardedBy("this") ReferenceEntry<K, V> copyEntry(ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) { if (original.getKey() == null) { // key collected return null; } ValueReference<K, V> valueReference = original.getValueReference(); V value = valueReference.get(); if ((value == null) && valueReference.isActive()) { // value collected return null; } ReferenceEntry<K, V> newEntry = map.entryFactory.copyEntry(this, original, newNext); newEntry.setValueReference(valueReference.copyFor(this.valueReferenceQueue, value, newEntry)); return newEntry; }
boolean removeLoadingValue(K key, int hash, LoadingValueReference<K, V> valueReference) { lock(); try { AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table; int index = hash & (table.length() - 1); ReferenceEntry<K, V> first = table.get(index); for (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) { K entryKey = e.getKey(); if (e.getHash() == hash && entryKey != null && map.keyEquivalence.equivalent(key, entryKey)) { ValueReference<K, V> v = e.getValueReference(); if (v == valueReference) { if (valueReference.isActive()) { e.setValueReference(valueReference.getOldValue()); } else { ReferenceEntry<K, V> newFirst = removeEntryFromChain(first, e); table.set(index, newFirst); } return true; } return false; } } return false; } finally { unlock(); postWriteCleanup(); } }
@Nullable V get(Object key, int hash) { try { if (count != 0) { // read-volatile long now = map.ticker.read(); ReferenceEntry<K, V> e = getLiveEntry(key, hash, now); if (e == null) { return null; } V value = e.getValueReference().get(); if (value != null) { recordRead(e, now); return scheduleRefresh(e, e.getKey(), hash, value, now, map.defaultLoader); } tryDrainReferenceQueues(); } return null; } finally { postReadCleanup(); } }
public void testRemovalListener_collected() { QueuingRemovalListener<Object, Object> listener = queuingRemovalListener(); LocalCache<Object, Object> map = makeLocalCache( createCacheBuilder().concurrencyLevel(1).softValues().removalListener(listener)); Segment<Object, Object> segment = map.segments[0]; assertTrue(listener.isEmpty()); Object one = new Object(); Object two = new Object(); Object three = new Object(); map.put(one, two); map.put(two, three); assertTrue(listener.isEmpty()); int hash = map.hash(one); ReferenceEntry<Object, Object> entry = segment.getEntry(one, hash); map.reclaimValue(entry.getValueReference()); assertNotified(listener, one, two, RemovalCause.COLLECTED); assertTrue(listener.isEmpty()); }
public void testDrainValueReferenceQueueOnWrite() { for (CacheBuilder<Object, Object> builder : allKeyValueStrengthMakers()) { LocalCache<Object, Object> map = makeLocalCache(builder.concurrencyLevel(1)); if (map.usesValueReferences()) { Segment<Object, Object> segment = map.segments[0]; Object keyOne = new Object(); int hashOne = map.hash(keyOne); Object valueOne = new Object(); Object keyTwo = new Object(); Object valueTwo = new Object(); map.put(keyOne, valueOne); ReferenceEntry<Object, Object> entry = segment.getEntry(keyOne, hashOne); ValueReference<Object, Object> valueReference = entry.getValueReference(); @SuppressWarnings("unchecked") Reference<Object> reference = (Reference) valueReference; reference.enqueue(); map.put(keyTwo, valueTwo); assertFalse(map.containsKey(keyOne)); assertFalse(map.containsValue(valueOne)); assertNull(map.get(keyOne)); assertEquals(1, map.size()); assertNull(segment.valueReferenceQueue.poll()); } } }
public void testDrainValueReferenceQueueOnRead() { for (CacheBuilder<Object, Object> builder : allKeyValueStrengthMakers()) { LocalCache<Object, Object> map = makeLocalCache(builder.concurrencyLevel(1)); if (map.usesValueReferences()) { Segment<Object, Object> segment = map.segments[0]; Object keyOne = new Object(); int hashOne = map.hash(keyOne); Object valueOne = new Object(); Object keyTwo = new Object(); map.put(keyOne, valueOne); ReferenceEntry<Object, Object> entry = segment.getEntry(keyOne, hashOne); ValueReference<Object, Object> valueReference = entry.getValueReference(); @SuppressWarnings("unchecked") Reference<Object> reference = (Reference) valueReference; reference.enqueue(); for (int i = 0; i < SMALL_MAX_SIZE; i++) { map.get(keyTwo); } assertFalse(map.containsKey(keyOne)); assertFalse(map.containsValue(valueOne)); assertNull(map.get(keyOne)); assertEquals(0, map.size()); assertNull(segment.valueReferenceQueue.poll()); } } }
public void testNewEntry() { for (CacheBuilder<Object, Object> builder : allEntryTypeMakers()) { LocalCache<Object, Object> map = makeLocalCache(builder); Object keyOne = new Object(); Object valueOne = new Object(); int hashOne = map.hash(keyOne); ReferenceEntry<Object, Object> entryOne = map.newEntry(keyOne, hashOne, null); ValueReference<Object, Object> valueRefOne = map.newValueReference(entryOne, valueOne, 1); assertSame(valueOne, valueRefOne.get()); entryOne.setValueReference(valueRefOne); assertSame(keyOne, entryOne.getKey()); assertEquals(hashOne, entryOne.getHash()); assertNull(entryOne.getNext()); assertSame(valueRefOne, entryOne.getValueReference()); Object keyTwo = new Object(); Object valueTwo = new Object(); int hashTwo = map.hash(keyTwo); ReferenceEntry<Object, Object> entryTwo = map.newEntry(keyTwo, hashTwo, entryOne); ValueReference<Object, Object> valueRefTwo = map.newValueReference(entryTwo, valueTwo, 1); assertSame(valueTwo, valueRefTwo.get()); entryTwo.setValueReference(valueRefTwo); assertSame(keyTwo, entryTwo.getKey()); assertEquals(hashTwo, entryTwo.getHash()); assertSame(entryOne, entryTwo.getNext()); assertSame(valueRefTwo, entryTwo.getValueReference()); } }