/*
* Copyright (c) 2008-2017, 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.internal.nearcache.impl.store;
import com.hazelcast.config.NearCacheConfig;
import com.hazelcast.internal.nearcache.impl.record.NearCacheObjectRecord;
import com.hazelcast.nio.serialization.Data;
import com.hazelcast.spi.serialization.SerializationService;
import static com.hazelcast.internal.nearcache.NearCache.CACHED_AS_NULL;
import static com.hazelcast.internal.nearcache.NearCacheRecord.TIME_NOT_SET;
import static com.hazelcast.util.Clock.currentTimeMillis;
/**
* {@link com.hazelcast.internal.nearcache.NearCacheRecordStore} implementation for Near Caches
* with {@link com.hazelcast.config.InMemoryFormat#OBJECT} in-memory-format.
*
* @param <K> the type of the key stored in Near Cache
* @param <V> the type of the value stored in Near Cache
*/
public class NearCacheObjectRecordStore<K, V> extends BaseHeapNearCacheRecordStore<K, V, NearCacheObjectRecord<V>> {
public NearCacheObjectRecordStore(String name,
NearCacheConfig nearCacheConfig,
SerializationService serializationService,
ClassLoader classLoader) {
super(name, nearCacheConfig, serializationService, classLoader);
}
@Override
protected long getKeyStorageMemoryCost(K key) {
// memory cost for "OBJECT" in memory format is totally not supported, so just return zero
return 0L;
}
@Override
protected long getRecordStorageMemoryCost(NearCacheObjectRecord record) {
// memory cost for "OBJECT" in memory format is totally not supported, so just return zero
return 0L;
}
@Override
protected NearCacheObjectRecord<V> valueToRecord(V value) {
value = toValue(value);
long creationTime = currentTimeMillis();
if (timeToLiveMillis > 0) {
return new NearCacheObjectRecord<V>(value, creationTime, creationTime + timeToLiveMillis);
} else {
return new NearCacheObjectRecord<V>(value, creationTime, TIME_NOT_SET);
}
}
@Override
protected void updateRecordValue(NearCacheObjectRecord<V> record, V value) {
record.setValue(toValue(value));
}
@Override
protected V recordToValue(NearCacheObjectRecord<V> record) {
if (record.getValue() == null) {
nearCacheStats.incrementMisses();
return (V) CACHED_AS_NULL;
}
return record.getValue();
}
@Override
public Object selectToSave(Object... candidates) {
Object selectedCandidate = null;
if (candidates != null && candidates.length > 0) {
for (Object candidate : candidates) {
// give priority to non Data typed candidate, so there will be no extra conversion from Data to Object
if (!(candidate instanceof Data)) {
selectedCandidate = candidate;
break;
}
}
if (selectedCandidate != null) {
return selectedCandidate;
} else {
// select a non-null candidate
for (Object candidate : candidates) {
if (candidate != null) {
selectedCandidate = candidate;
break;
}
}
}
}
return selectedCandidate;
}
}