| /* |
| * 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. |
| */ |
| |
| package org.apache.lucene.search; |
| |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| /** |
| * Used for defining custom algorithms to allow searches to early terminate |
| */ |
| abstract class HitsThresholdChecker { |
| /** |
| * Implementation of HitsThresholdChecker which allows global hit counting |
| */ |
| private static class GlobalHitsThresholdChecker extends HitsThresholdChecker { |
| private final int totalHitsThreshold; |
| private final AtomicLong globalHitCount; |
| |
| public GlobalHitsThresholdChecker(int totalHitsThreshold) { |
| |
| if (totalHitsThreshold < 0) { |
| throw new IllegalArgumentException("totalHitsThreshold must be >= 0, got " + totalHitsThreshold); |
| } |
| |
| this.totalHitsThreshold = totalHitsThreshold; |
| this.globalHitCount = new AtomicLong(); |
| } |
| |
| @Override |
| public void incrementHitCount() { |
| globalHitCount.incrementAndGet(); |
| } |
| |
| @Override |
| public boolean isThresholdReached(){ |
| return globalHitCount.get() > totalHitsThreshold; |
| } |
| |
| @Override |
| public ScoreMode scoreMode() { |
| return totalHitsThreshold == Integer.MAX_VALUE ? ScoreMode.COMPLETE : ScoreMode.TOP_SCORES; |
| } |
| |
| @Override |
| public int getHitsThreshold() { |
| return totalHitsThreshold; |
| } |
| } |
| |
| /** |
| * Default implementation of HitsThresholdChecker to be used for single threaded execution |
| */ |
| private static class LocalHitsThresholdChecker extends HitsThresholdChecker { |
| private final int totalHitsThreshold; |
| private int hitCount; |
| |
| public LocalHitsThresholdChecker(int totalHitsThreshold) { |
| |
| if (totalHitsThreshold < 0) { |
| throw new IllegalArgumentException("totalHitsThreshold must be >= 0, got " + totalHitsThreshold); |
| } |
| |
| this.totalHitsThreshold = totalHitsThreshold; |
| } |
| |
| @Override |
| public void incrementHitCount() { |
| ++hitCount; |
| } |
| |
| @Override |
| public boolean isThresholdReached() { |
| return hitCount > totalHitsThreshold; |
| } |
| |
| @Override |
| public ScoreMode scoreMode() { |
| return totalHitsThreshold == Integer.MAX_VALUE ? ScoreMode.COMPLETE : ScoreMode.TOP_SCORES; |
| } |
| |
| @Override |
| public int getHitsThreshold() { |
| return totalHitsThreshold; |
| } |
| } |
| |
| /* |
| * Returns a threshold checker that is useful for single threaded searches |
| */ |
| public static HitsThresholdChecker create(final int totalHitsThreshold) { |
| return new LocalHitsThresholdChecker(totalHitsThreshold); |
| } |
| |
| /* |
| * Returns a threshold checker that is based on a shared counter |
| */ |
| public static HitsThresholdChecker createShared(final int totalHitsThreshold) { |
| return new GlobalHitsThresholdChecker(totalHitsThreshold); |
| } |
| |
| public abstract void incrementHitCount(); |
| public abstract ScoreMode scoreMode(); |
| public abstract int getHitsThreshold(); |
| public abstract boolean isThresholdReached(); |
| } |