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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
/**
* The hll package contains a high performance implementation of Phillipe
* Flajolet's HLL sketch with significantly improved error behavior.
*
* <p>If the ONLY use case for sketching is counting uniques and merging, the
* HLL sketch is the highest performing in terms of accuracy for space
* consumed. For large counts, this HLL version will be 2 to 16 times
* smaller for the same accuracy than the Theta Sketches.
*
* <p>HLL sketches do not retain any of the hash values of the associated unique identifiers,
* so if there is any anticipation of a future need to leverage associations with these
* retained hash values, Theta Sketches would be a better choice.</p>
*
* <p>HLL sketches cannot be intermixed or merged in any way with Theta Sketches.
* </p>
*
* @author Lee Rhodes
* @author Kevin Lang
*/
package org.apache.datasketches.hll;