com.hazelcast.cardinality.impl.CardinalityEstimatorContainer Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2018, 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.cardinality.impl;
import com.hazelcast.cardinality.impl.hyperloglog.HyperLogLog;
import com.hazelcast.cardinality.impl.hyperloglog.impl.HyperLogLogImpl;
import com.hazelcast.nio.ObjectDataInput;
import com.hazelcast.nio.ObjectDataOutput;
import com.hazelcast.nio.serialization.IdentifiedDataSerializable;
import com.hazelcast.spi.merge.SplitBrainMergePolicy;
import com.hazelcast.spi.merge.SplitBrainMergeTypes.CardinalityEstimatorMergeTypes;
import com.hazelcast.spi.serialization.SerializationService;
import java.io.IOException;
import static com.hazelcast.config.CardinalityEstimatorConfig.DEFAULT_ASYNC_BACKUP_COUNT;
import static com.hazelcast.config.CardinalityEstimatorConfig.DEFAULT_SYNC_BACKUP_COUNT;
import static com.hazelcast.spi.impl.merge.MergingValueFactory.createMergingEntry;
public class CardinalityEstimatorContainer
implements IdentifiedDataSerializable {
HyperLogLog hll;
private int backupCount;
private int asyncBackupCount;
public CardinalityEstimatorContainer() {
this(DEFAULT_SYNC_BACKUP_COUNT, DEFAULT_ASYNC_BACKUP_COUNT);
}
public CardinalityEstimatorContainer(int backupCount, int asyncBackupCount) {
this.hll = new HyperLogLogImpl();
this.backupCount = backupCount;
this.asyncBackupCount = asyncBackupCount;
}
public void add(long hash) {
hll.add(hash);
}
public long estimate() {
return hll.estimate();
}
public int getBackupCount() {
return backupCount;
}
public int getAsyncBackupCount() {
return asyncBackupCount;
}
public int getTotalBackupCount() {
return backupCount + asyncBackupCount;
}
/**
* Merges the given {@link CardinalityEstimatorMergeTypes} via the given {@link SplitBrainMergePolicy}.
*
* @param mergingEntry the {@link CardinalityEstimatorMergeTypes} instance to merge
* @param mergePolicy the {@link SplitBrainMergePolicy} instance to apply
* @param serializationService the {@link SerializationService} to inject dependencies
* @return the used {@link HyperLogLog} if merge is applied, otherwise {@code null}
*/
public HyperLogLog merge(CardinalityEstimatorMergeTypes mergingEntry,
SplitBrainMergePolicy mergePolicy,
SerializationService serializationService) {
serializationService.getManagedContext().initialize(mergingEntry);
serializationService.getManagedContext().initialize(mergePolicy);
String name = mergingEntry.getKey();
if (hll.estimate() != 0) {
CardinalityEstimatorMergeTypes existingEntry = createMergingEntry(serializationService, name, hll);
HyperLogLog newValue = mergePolicy.merge(mergingEntry, existingEntry);
if (newValue != null && !newValue.equals(hll)) {
setValue(newValue);
return hll;
}
} else {
HyperLogLog newValue = mergePolicy.merge(mergingEntry, null);
if (newValue != null) {
setValue(newValue);
return hll;
}
}
return null;
}
public void setValue(HyperLogLog hll) {
this.hll = hll;
}
@Override
public void writeData(ObjectDataOutput out) throws IOException {
out.writeObject(hll);
out.writeInt(backupCount);
out.writeInt(asyncBackupCount);
}
@Override
public void readData(ObjectDataInput in) throws IOException {
hll = in.readObject();
backupCount = in.readInt();
asyncBackupCount = in.readInt();
}
@Override
public int getFactoryId() {
return CardinalityEstimatorDataSerializerHook.F_ID;
}
@Override
public int getId() {
return CardinalityEstimatorDataSerializerHook.CARDINALITY_EST_CONTAINER;
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
CardinalityEstimatorContainer that = (CardinalityEstimatorContainer) o;
return hll.equals(that.hll);
}
@Override
public int hashCode() {
return hll.hashCode();
}
}