001/**
002 *
003 * Copyright (c) 2005, European Commission project OneLab under contract 034819
004 * (http://www.one-lab.org)
005 * 
006 * All rights reserved.
007 * Redistribution and use in source and binary forms, with or 
008 * without modification, are permitted provided that the following 
009 * conditions are met:
010 *  - Redistributions of source code must retain the above copyright 
011 *    notice, this list of conditions and the following disclaimer.
012 *  - Redistributions in binary form must reproduce the above copyright 
013 *    notice, this list of conditions and the following disclaimer in 
014 *    the documentation and/or other materials provided with the distribution.
015 *  - Neither the name of the University Catholique de Louvain - UCL
016 *    nor the names of its contributors may be used to endorse or 
017 *    promote products derived from this software without specific prior 
018 *    written permission.
019 *    
020 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
021 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
022 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
023 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
024 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
025 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
026 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
027 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
028 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
029 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
030 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
031 * POSSIBILITY OF SUCH DAMAGE.
032 */
033
034/**
035 * Licensed to the Apache Software Foundation (ASF) under one
036 * or more contributor license agreements.  See the NOTICE file
037 * distributed with this work for additional information
038 * regarding copyright ownership.  The ASF licenses this file
039 * to you under the Apache License, Version 2.0 (the
040 * "License"); you may not use this file except in compliance
041 * with the License.  You may obtain a copy of the License at
042 *
043 *     http://www.apache.org/licenses/LICENSE-2.0
044 *
045 * Unless required by applicable law or agreed to in writing, software
046 * distributed under the License is distributed on an "AS IS" BASIS,
047 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
048 * See the License for the specific language governing permissions and
049 * limitations under the License.
050 */
051package org.apache.hadoop.util.bloom;
052
053import org.apache.hadoop.classification.InterfaceAudience;
054import org.apache.hadoop.classification.InterfaceStability;
055
056/**
057 * Defines the different remove scheme for retouched Bloom filters.
058 * <p>
059 * Originally created by
060 * <a href="http://www.one-lab.org">European Commission One-Lab Project 034819</a>.
061 */
062@InterfaceAudience.Public
063@InterfaceStability.Stable
064public interface RemoveScheme {
065  /**
066   * Random selection.
067   * <p>
068   * The idea is to randomly select a bit to reset.
069   */
070  public final static short RANDOM = 0;
071
072  /**
073   * MinimumFN Selection.
074   * <p>
075   * The idea is to select the bit to reset that will generate the minimum
076   * number of false negative.
077   */
078  public final static short MINIMUM_FN = 1;
079
080  /**
081   * MaximumFP Selection.
082   * <p>
083   * The idea is to select the bit to reset that will remove the maximum number
084   * of false positive.
085   */
086  public final static short MAXIMUM_FP = 2;
087
088  /**
089   * Ratio Selection.
090   * <p>
091   * The idea is to select the bit to reset that will, at the same time, remove
092   * the maximum number of false positve while minimizing the amount of false
093   * negative generated.
094   */
095  public final static short RATIO = 3;
096}