/*
* 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.cardinality.impl.hyperloglog.impl;
import com.hazelcast.nio.serialization.IdentifiedDataSerializable;
public interface HyperLogLogEncoder extends IdentifiedDataSerializable {
/**
* Computes a new estimate for the current status of the registers.
*
* @return a cardinality estimation.
*/
long estimate();
/**
* Aggregates the hash value in the HyperLogLog registers, and returns a hint if the
* operation migth have affected the cardinality, it is just a hint, and it relies to
* the respective implementation.
*
* @param hash the value to aggregate
* @return boolean hint, if the latest operation might have affected the cardinality.
*/
boolean add(long hash);
/**
* Returns the size in memory occupied (in bytes) for this implementation of HyperLogLog.
*
* @return the size in memory.
*/
int getMemoryFootprint();
/**
* Returns the encoding type of this instance; see: {@link HyperLogLogEncoding}
* @return {@link HyperLogLogEncoding}
*/
HyperLogLogEncoding getEncodingType();
}