/*
* Copyright (C) 2011 Clearspring Technologies, Inc.
*
* 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 org.apache.geode.internal.hll;
import java.io.IOException;
public interface ICardinality {
/**
* @param o stream element
* @return false if the value returned by cardinality() is unaffected by the appearance of o in
* the stream.
*/
boolean offer(Object o);
/**
* Offer the value as a hashed long value
*
* @param hashedLong - the hash of the item to offer to the estimator
* @return false if the value returned by cardinality() is unaffected by the appearance of
* hashedLong in the stream
*/
boolean offerHashed(long hashedLong);
/**
* Offer the value as a hashed long value
*
* @param hashedInt - the hash of the item to offer to the estimator
* @return false if the value returned by cardinality() is unaffected by the appearance of
* hashedInt in the stream
*/
boolean offerHashed(int hashedInt);
/**
* @return the number of unique elements in the stream or an estimate thereof
*/
long cardinality();
/**
* @return size in bytes needed for serialization
*/
int sizeof();
/**
* @return byte[]
* @throws IOException
*/
byte[] getBytes() throws IOException;
/**
* Merges estimators to produce a new estimator for the combined streams of this estimator and
* those passed as arguments.
* <p/>
* Nor this estimator nor the one passed as parameters are modified.
*
* @param estimators Zero or more compatible estimators
* @throws CardinalityMergeException If at least one of the estimators is not compatible with this
* one
*/
ICardinality merge(ICardinality... estimators) throws CardinalityMergeException;
}