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     */
051    package org.apache.hadoop.util.bloom;
052    
053    import org.apache.hadoop.classification.InterfaceAudience;
054    import 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
064    public 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    }