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com.hazelcast.hibernate.local.LocalRegionCache Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2016, Hazelcast, Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hazelcast.hibernate.local;
import com.hazelcast.config.MapConfig;
import com.hazelcast.core.HazelcastInstance;
import com.hazelcast.core.ITopic;
import com.hazelcast.core.Message;
import com.hazelcast.core.MessageListener;
import com.hazelcast.hibernate.CacheEnvironment;
import com.hazelcast.hibernate.HazelcastTimestamper;
import com.hazelcast.hibernate.RegionCache;
import com.hazelcast.hibernate.serialization.Expirable;
import com.hazelcast.hibernate.serialization.ExpiryMarker;
import com.hazelcast.hibernate.serialization.MarkerWrapper;
import com.hazelcast.hibernate.serialization.Value;
import com.hazelcast.util.Clock;
import com.hazelcast.util.EmptyStatement;
import org.hibernate.cache.spi.CacheDataDescription;
import org.hibernate.cache.spi.access.SoftLock;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicLong;
/**
* Local only {@link com.hazelcast.hibernate.RegionCache} implementation
* based on a topic to distribute cache updates.
*/
public class LocalRegionCache implements RegionCache {
private static final long SEC_TO_MS = 1000L;
private static final int MAX_SIZE = 100000;
private static final float BASE_EVICTION_RATE = 0.2F;
protected final HazelcastInstance hazelcastInstance;
protected final ITopic topic;
protected final MessageListener messageListener;
protected final ConcurrentMap cache;
protected final Comparator versionComparator;
protected final AtomicLong markerIdCounter;
protected MapConfig config;
/**
* @param name the name for this region cache, which is also used to retrieve configuration/topic
* @param hazelcastInstance the {@code HazelcastInstance} to which this region cache belongs, used to retrieve
* configuration and to lookup an {@link ITopic} to register a {@link MessageListener}
* with (optional)
* @param metadata metadata describing the cached data, used to compare data versions (optional)
*/
public LocalRegionCache(final String name, final HazelcastInstance hazelcastInstance,
final CacheDataDescription metadata) {
this(name, hazelcastInstance, metadata, true);
}
/**
* @param name the name for this region cache, which is also used to retrieve configuration/topic
* @param hazelcastInstance the {@code HazelcastInstance} to which this region cache belongs, used to retrieve
* configuration and to lookup an {@link ITopic} to register a {@link MessageListener}
* with if {@code withTopic} is {@code true} (optional)
* @param metadata metadata describing the cached data, used to compare data versions (optional)
* @param withTopic {@code true} to register a {@link MessageListener} with the {@link ITopic} whose name
* matches this region cache if a {@code HazelcastInstance} was provided to look
* up the topic; otherwise, {@code false} not to register a listener even if an instance
* was provided
*/
public LocalRegionCache(final String name, final HazelcastInstance hazelcastInstance,
final CacheDataDescription metadata, final boolean withTopic) {
this.hazelcastInstance = hazelcastInstance;
try {
config = hazelcastInstance != null ? hazelcastInstance.getConfig().findMapConfig(name) : null;
} catch (UnsupportedOperationException ignored) {
EmptyStatement.ignore(ignored);
}
versionComparator = metadata != null && metadata.isVersioned() ? metadata.getVersionComparator() : null;
cache = new ConcurrentHashMap();
markerIdCounter = new AtomicLong();
messageListener = createMessageListener();
if (withTopic && hazelcastInstance != null) {
topic = hazelcastInstance.getTopic(name);
topic.addMessageListener(messageListener);
} else {
topic = null;
}
}
@Override
public Object get(final Object key, long txTimestamp) {
final Expirable value = cache.get(key);
return value == null ? null : value.getValue(txTimestamp);
}
@Override
public boolean insert(final Object key, final Object value, final Object currentVersion) {
final Value newValue = new Value(currentVersion, nextTimestamp(), value);
return cache.putIfAbsent(key, newValue) == null;
}
@Override
public boolean put(final Object key, final Object value, final long txTimestamp, final Object version) {
while (true) {
Expirable previous = cache.get(key);
Value newValue = new Value(version, nextTimestamp(), value);
if (previous == null) {
if (cache.putIfAbsent(key, newValue) == null) {
return true;
}
} else if (previous.isReplaceableBy(txTimestamp, version, versionComparator)) {
if (cache.replace(key, previous, newValue)) {
return true;
}
} else {
return false;
}
}
}
@Override
public boolean update(final Object key, final Object newValue, final Object newVersion, final SoftLock softLock) {
boolean updated = false;
while (true) {
Expirable original = cache.get(key);
Expirable revised;
long timestamp = nextTimestamp();
if (original == null) {
// The entry must have expired. it should be safe to update
revised = new Value(newVersion, timestamp, newValue);
updated = true;
if (cache.putIfAbsent(key, revised) == null) {
break;
}
} else {
if (softLock instanceof MarkerWrapper) {
final ExpiryMarker unwrappedMarker = ((MarkerWrapper) softLock).getMarker();
if (original.matches(unwrappedMarker)) {
// The lock matches
final ExpiryMarker marker = (ExpiryMarker) original;
if (marker.isConcurrent()) {
revised = marker.expire(timestamp);
updated = false;
} else {
revised = new Value(newVersion, timestamp, newValue);
updated = true;
}
if (cache.replace(key, original, revised)) {
break;
}
} else if (original.getValue() == null) {
// It's marked for expiration, leave it as is
updated = false;
break;
} else {
// It's a value. Instead of removing it, expire it to prevent stale from in progress
// transactions being put in the cache
revised = new ExpiryMarker(newVersion, timestamp, nextMarkerId()).expire(timestamp);
updated = false;
if (cache.replace(key, original, revised)) {
break;
}
}
} else {
break;
}
}
}
maybeNotifyTopic(key, newValue, newVersion);
return updated;
}
protected void maybeNotifyTopic(final Object key, final Object value, final Object version) {
if (topic != null) {
topic.publish(createMessage(key, value, version));
}
}
protected Object createMessage(final Object key, final Object value, final Object currentVersion) {
return new Invalidation(key, currentVersion);
}
protected MessageListener createMessageListener() {
return new MessageListener() {
@Override
public void onMessage(final Message message) {
maybeInvalidate(message.getMessageObject());
}
};
}
@Override
public boolean remove(final Object key) {
final Expirable value = cache.remove(key);
maybeNotifyTopic(key, null, (value == null) ? null : value.getVersion());
return (value != null);
}
@Override
public SoftLock tryLock(final Object key, final Object version) {
ExpiryMarker marker;
String markerId = nextMarkerId();
while (true) {
final Expirable original = cache.get(key);
long timeout = nextTimestamp() + CacheEnvironment.getDefaultCacheTimeoutInMillis();
if (original == null) {
marker = new ExpiryMarker(version, timeout, markerId);
if (cache.putIfAbsent(key, marker) == null) {
break;
}
} else {
marker = original.markForExpiration(timeout, markerId);
if (cache.replace(key, original, marker)) {
break;
}
}
}
return new MarkerWrapper(marker);
}
@Override
public void unlock(final Object key, final SoftLock lock) {
while (true) {
final Expirable original = cache.get(key);
if (original != null) {
if (!(lock instanceof MarkerWrapper)) {
break;
}
final ExpiryMarker unwrappedMarker = ((MarkerWrapper) lock).getMarker();
if (original.matches(unwrappedMarker)) {
final Expirable revised = ((ExpiryMarker) original).expire(nextTimestamp());
if (cache.replace(key, original, revised)) {
break;
}
} else if (original.getValue() != null) {
if (cache.remove(key, original)) {
break;
}
} else {
break;
}
} else {
break;
}
}
maybeNotifyTopic(key, null, null);
}
@Override
public boolean contains(final Object key) {
return cache.containsKey(key);
}
@Override
public void clear() {
cache.clear();
maybeNotifyTopic(null, null, null);
}
@Override
public long size() {
return cache.size();
}
@Override
public long getSizeInMemory() {
return 0;
}
@Override
public Map asMap() {
return cache;
}
void cleanup() {
final int maxSize;
final long timeToLive;
if (config != null) {
maxSize = config.getMaxSizeConfig().getSize();
timeToLive = config.getTimeToLiveSeconds() * SEC_TO_MS;
} else {
maxSize = MAX_SIZE;
timeToLive = CacheEnvironment.getDefaultCacheTimeoutInMillis();
}
boolean limitSize = maxSize > 0 && maxSize != Integer.MAX_VALUE;
if (limitSize || timeToLive > 0) {
List entries = searchEvictableEntries(timeToLive, limitSize);
final int diff = cache.size() - maxSize;
final int evictionRate = calculateEvictionRate(diff, maxSize);
if (evictionRate > 0 && entries != null) {
evictEntries(entries, evictionRate);
}
}
}
protected void maybeInvalidate(final Object messageObject) {
Invalidation invalidation = (Invalidation) messageObject;
Object key = invalidation.getKey();
if (key == null) {
// Invalidate the entire region cache.
cache.clear();
} else if (versionComparator == null) {
// For an unversioned entity or collection we can only invalidate the entry.
cache.remove(key);
} else {
// For versioned entities we can avoid the invalidation if both we and the remote node know the version,
// AND our version is definitely equal or higher. Otherwise, we have to just invalidate our entry.
final Expirable value = cache.get(key);
if (value != null) {
maybeInvalidateVersionedEntity(key, value, invalidation.getVersion());
}
}
}
private void maybeInvalidateVersionedEntity(final Object key, final Expirable value, final Object newVersion) {
if (newVersion == null) {
// This invalidation was for an entity with unknown version. Just invalidate the entry
// unconditionally.
cache.remove(key);
} else {
// Invalidate our entry only if it was of a lower version.
Object currentVersion = value.getVersion();
if (versionComparator.compare(currentVersion, newVersion) < 0) {
cache.remove(key, value);
}
}
}
private String nextMarkerId() {
return Long.toString(markerIdCounter.getAndIncrement());
}
protected long nextTimestamp() {
return hazelcastInstance == null ? Clock.currentTimeMillis()
: HazelcastTimestamper.nextTimestamp(hazelcastInstance);
}
private List searchEvictableEntries(final long timeToLive, final boolean limitSize) {
List entries = null;
Iterator> iter = cache.entrySet().iterator();
long now = nextTimestamp();
while (iter.hasNext()) {
final Entry e = iter.next();
final Object k = e.getKey();
final Expirable expirable = e.getValue();
if (expirable instanceof ExpiryMarker) {
continue;
}
final Value v = (Value) expirable;
if (timeToLive > 0 && v.getTimestamp() + timeToLive < now) {
iter.remove();
} else if (limitSize) {
if (entries == null) {
// Use a List rather than a Set for correctness. Using a Set, especially a TreeSet
// based on EvictionEntry.compareTo, causes evictions to be processed incorrectly
// when two or more entries in the map have the same timestamp. In such a case, the
// _first_ entry at a given timestamp is the only one that can be evicted because
// TreeSet does not add "equivalent" entries. A second benefit of using a List is
// that the cost of sorting the entries is not incurred if eviction isn't performed
entries = new ArrayList(cache.size());
}
entries.add(new EvictionEntry(k, v));
}
}
return entries;
}
private int calculateEvictionRate(final int diff, final int maxSize) {
return diff >= 0 ? (diff + (int) (maxSize * BASE_EVICTION_RATE)) : 0;
}
private void evictEntries(final List entries, final int evictionRate) {
// Only sort the entries if we're going to evict some
Collections.sort(entries);
int removed = 0;
for (EvictionEntry entry : entries) {
if (cache.remove(entry.key, entry.value) && ++removed == evictionRate) {
break;
}
}
}
/**
* Inner class that instances represent an entry marked for eviction
*/
private static final class EvictionEntry implements Comparable {
final Object key;
final Value value;
private EvictionEntry(final Object key, final Value value) {
this.key = key;
this.value = value;
}
@Override
public int compareTo(final EvictionEntry o) {
final long thisVal = this.value.getTimestamp();
final long anotherVal = o.value.getTimestamp();
return (thisVal < anotherVal ? -1 : (thisVal == anotherVal ? 0 : 1));
}
@Override
public boolean equals(final Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
EvictionEntry that = (EvictionEntry) o;
return (key == null ? that.key == null : key.equals(that.key))
&& (value == null ? that.value == null : value.equals(that.value));
}
@Override
public int hashCode() {
return key == null ? 0 : key.hashCode();
}
}
}
