| /* |
| * 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.geode.cache.lucene.internal.distributed; |
| |
| import java.io.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.Comparator; |
| import java.util.List; |
| |
| import org.apache.geode.cache.lucene.LuceneQueryFactory; |
| import org.apache.geode.internal.serialization.DataSerializableFixedID; |
| import org.apache.geode.internal.serialization.DeserializationContext; |
| import org.apache.geode.internal.serialization.KnownVersion; |
| import org.apache.geode.internal.serialization.SerializationContext; |
| |
| /** |
| * Holds a ordered collection of entries matching a search query. |
| * |
| * @param <K> the type of key |
| */ |
| public class TopEntries<K> implements DataSerializableFixedID { |
| // ordered collection of entries |
| private List<EntryScore<K>> hits = new ArrayList<>(); |
| |
| // the maximum number of entries stored in this |
| private int limit; |
| |
| // comparator to order entryScore instances |
| final Comparator<EntryScore<K>> comparator = new EntryScoreComparator(); |
| |
| public TopEntries() { |
| this(LuceneQueryFactory.DEFAULT_LIMIT); |
| } |
| |
| public TopEntries(int limit) { |
| if (limit < 0) { |
| throw new IllegalArgumentException(); |
| } |
| this.limit = limit; |
| } |
| |
| /** |
| * Adds an entry to the collection. The new entry must have a lower score than all previous |
| * entries added to the collection. The new entry will be ignored if the limit is already reached. |
| * |
| */ |
| public void addHit(EntryScore<K> entry) { |
| if (hits.size() > 0) { |
| EntryScore lastEntry = hits.get(hits.size() - 1); |
| if (comparator.compare(lastEntry, entry) < 0) { |
| throw new IllegalArgumentException(); |
| } |
| } |
| |
| if (hits.size() >= limit) { |
| return; |
| } |
| |
| hits.add(entry); |
| } |
| |
| /** |
| * @return count of entries in the collection |
| */ |
| public int size() { |
| return hits.size(); |
| } |
| |
| /** |
| * @return The entries collection managed by this instance |
| */ |
| public List<EntryScore<K>> getHits() { |
| return hits; |
| } |
| |
| /** |
| * @return The maximum capacity of this collection |
| */ |
| public int getLimit() { |
| return limit; |
| } |
| |
| /** |
| * Compares scores of two entries using natural ordering. I.e. it returns -1 if the first entry's |
| * score is less than the second one. |
| */ |
| class EntryScoreComparator implements Comparator<EntryScore<K>> { |
| @Override |
| public int compare(EntryScore<K> o1, EntryScore<K> o2) { |
| return Float.compare(o1.getScore(), o2.getScore()); |
| } |
| } |
| |
| @Override |
| public KnownVersion[] getSerializationVersions() { |
| // TODO Auto-generated method stub |
| return null; |
| } |
| |
| @Override |
| public int getDSFID() { |
| return LUCENE_TOP_ENTRIES; |
| } |
| |
| @Override |
| public void toData(DataOutput out, |
| SerializationContext context) throws IOException { |
| out.writeInt(limit); |
| context.getSerializer().writeObject(hits, out); |
| } |
| |
| @Override |
| public void fromData(DataInput in, |
| DeserializationContext context) throws IOException, ClassNotFoundException { |
| limit = in.readInt(); |
| hits = context.getDeserializer().readObject(in); |
| }; |
| } |