com.hazelcast.client.map.impl.nearcache.ClientHeapNearCache Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2015, 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.client.map.impl.nearcache;
import com.hazelcast.cache.impl.nearcache.NearCache;
import com.hazelcast.client.spi.ClientContext;
import com.hazelcast.client.spi.impl.ClientExecutionServiceImpl;
import com.hazelcast.config.EvictionPolicy;
import com.hazelcast.config.InMemoryFormat;
import com.hazelcast.config.NearCacheConfig;
import com.hazelcast.internal.serialization.SerializationService;
import com.hazelcast.map.impl.nearcache.NearCacheRecord;
import com.hazelcast.monitor.impl.NearCacheStatsImpl;
import com.hazelcast.util.Clock;
import com.hazelcast.util.ExceptionUtil;
import java.util.Comparator;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* Implementation of the {@link NearCache}.
*
* todo: improve javadoc.
*
* @param
*/
public class ClientHeapNearCache
implements NearCache {
/**
* Eviction factor
*/
private static final double EVICTION_FACTOR = 0.2;
/**
* TTL Clean up interval
*/
private static final int TTL_CLEANUP_INTERVAL_MILLS = 5000;
private final int maxSize;
private final long maxIdleMillis;
private final long timeToLiveMillis;
private final boolean invalidateOnChange;
private final EvictionPolicy evictionPolicy;
private final InMemoryFormat inMemoryFormat;
private final String mapName;
private final ClientContext context;
private final AtomicBoolean canCleanUp;
private final AtomicBoolean canEvict;
private final ConcurrentMap cache;
private final NearCacheStatsImpl stats;
private final Comparator selectedComparator;
private volatile long lastCleanup;
public ClientHeapNearCache(String mapName, ClientContext context, NearCacheConfig nearCacheConfig) {
this.mapName = mapName;
this.context = context;
maxSize = nearCacheConfig.getMaxSize();
maxIdleMillis = TimeUnit.SECONDS.toMillis(nearCacheConfig.getMaxIdleSeconds());
inMemoryFormat = nearCacheConfig.getInMemoryFormat();
if (inMemoryFormat != InMemoryFormat.BINARY && inMemoryFormat != InMemoryFormat.OBJECT) {
throw new IllegalArgumentException("Illegal in-memory-format: " + inMemoryFormat);
}
timeToLiveMillis = TimeUnit.SECONDS.toMillis(nearCacheConfig.getTimeToLiveSeconds());
invalidateOnChange = nearCacheConfig.isInvalidateOnChange();
evictionPolicy = EvictionPolicy.valueOf(nearCacheConfig.getEvictionPolicy());
selectedComparator = NearCacheRecord.getComparator(evictionPolicy);
cache = new ConcurrentHashMap();
canCleanUp = new AtomicBoolean(true);
canEvict = new AtomicBoolean(true);
lastCleanup = Clock.currentTimeMillis();
stats = new NearCacheStatsImpl();
}
@Override
public void put(K key, Object object) {
fireTtlCleanup();
if (evictionPolicy == EvictionPolicy.NONE && cache.size() >= maxSize) {
return;
}
if (evictionPolicy != EvictionPolicy.NONE && cache.size() >= maxSize) {
fireEvictCache();
}
Object value;
if (object == null) {
value = NULL_OBJECT;
} else {
SerializationService serializationService = context.getSerializationService();
if (inMemoryFormat == InMemoryFormat.BINARY) {
value = serializationService.toData(object);
} else if (inMemoryFormat == InMemoryFormat.OBJECT) {
value = serializationService.toObject(object);
} else {
throw new IllegalArgumentException();
}
}
cache.put(key, new NearCacheRecord(key, value));
}
private void fireEvictCache() {
if (canEvict.compareAndSet(true, false)) {
try {
final ClientExecutionServiceImpl executionService = (ClientExecutionServiceImpl) context.getExecutionService();
executionService.executeInternal(new Runnable() {
public void run() {
try {
Set records = new TreeSet(selectedComparator);
records.addAll(cache.values());
int evictSize = (int) (cache.size() * EVICTION_FACTOR);
int i = 0;
for (NearCacheRecord record : records) {
cache.remove(record.getKey());
if (++i > evictSize) {
break;
}
}
} finally {
canEvict.set(true);
}
if (cache.size() >= maxSize && canEvict.compareAndSet(true, false)) {
try {
executionService.executeInternal(this);
} catch (RejectedExecutionException e) {
canEvict.set(true);
}
}
}
});
} catch (RejectedExecutionException e) {
canEvict.set(true);
} catch (Exception e) {
throw ExceptionUtil.rethrow(e);
}
}
}
private void fireTtlCleanup() {
if (Clock.currentTimeMillis() < (lastCleanup + TTL_CLEANUP_INTERVAL_MILLS)) {
return;
}
if (canCleanUp.compareAndSet(true, false)) {
try {
ClientExecutionServiceImpl executionService = (ClientExecutionServiceImpl) context.getExecutionService();
executionService.executeInternal(new Runnable() {
public void run() {
try {
lastCleanup = Clock.currentTimeMillis();
for (Map.Entry entry : cache.entrySet()) {
if (entry.getValue().isExpired(maxIdleMillis, timeToLiveMillis)) {
cache.remove(entry.getKey());
}
}
} finally {
canCleanUp.set(true);
}
}
});
} catch (RejectedExecutionException e) {
canCleanUp.set(true);
} catch (Exception e) {
throw ExceptionUtil.rethrow(e);
}
}
}
@Override
public String getName() {
return mapName;
}
@Override
public Object get(K key) {
fireTtlCleanup();
NearCacheRecord record = cache.get(key);
if (record != null) {
record.access();
if (record.isExpired(maxIdleMillis, timeToLiveMillis)) {
cache.remove(key);
stats.incrementMisses();
return null;
}
if (record.getValue().equals(NULL_OBJECT)) {
stats.incrementMisses();
return NULL_OBJECT;
}
stats.incrementHits();
return inMemoryFormat.equals(InMemoryFormat.BINARY)
? context.getSerializationService().toObject(record.getValue()) : record.getValue();
} else {
stats.incrementMisses();
return null;
}
}
@Override
public boolean remove(K key) {
return null != cache.remove(key);
}
@Override
public NearCacheStatsImpl getNearCacheStats() {
long ownedEntryCount = 0;
long ownedEntryMemory = 0;
for (NearCacheRecord record : cache.values()) {
ownedEntryCount++;
ownedEntryMemory += record.getCost();
}
stats.setOwnedEntryCount(ownedEntryCount);
stats.setOwnedEntryMemoryCost(ownedEntryMemory);
return stats;
}
@Override
public Object selectToSave(Object... candidates) {
throw new UnsupportedOperationException();
}
@Override
public int size() {
return cache.size();
}
@Override
public void clear() {
cache.clear();
}
@Override
public void destroy() {
cache.clear();
}
@Override
public boolean isInvalidateOnChange() {
return invalidateOnChange;
}
@Override
public InMemoryFormat getInMemoryFormat() {
return inMemoryFormat;
}
}