| using System; |
| |
| namespace Lucene.Net.Search |
| { |
| /* |
| * 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. |
| */ |
| |
| using AtomicReaderContext = Lucene.Net.Index.AtomicReaderContext; |
| |
| /// <summary> |
| /// A <see cref="ICollector"/> which allows running a search with several |
| /// <see cref="ICollector"/>s. It offers a static <see cref="Wrap(ICollector[])"/> method which accepts a |
| /// list of collectors and wraps them with <see cref="MultiCollector"/>, while |
| /// filtering out the <c>null</c> ones. |
| /// </summary> |
| public class MultiCollector : ICollector |
| { |
| /// <summary> |
| /// Wraps a list of <see cref="ICollector"/>s with a <see cref="MultiCollector"/>. This |
| /// method works as follows: |
| /// <list type="bullet"> |
| /// <item><description>Filters out the <c>null</c> collectors, so they are not used |
| /// during search time.</description></item> |
| /// <item><description>If the input contains 1 real collector (i.e. non-<c>null</c> ), |
| /// it is returned.</description></item> |
| /// <item><description>Otherwise the method returns a <see cref="MultiCollector"/> which wraps the |
| /// non-<code>null</code> ones.</description></item> |
| /// </list> |
| /// </summary> |
| /// <exception cref="ArgumentException"> |
| /// if either 0 collectors were input, or all collectors are |
| /// <c>null</c>. </exception> |
| public static ICollector Wrap(params ICollector[] collectors) |
| { |
| // For the user's convenience, we allow null collectors to be passed. |
| // However, to improve performance, these null collectors are found |
| // and dropped from the array we save for actual collection time. |
| int n = 0; |
| foreach (ICollector c in collectors) |
| { |
| if (c != null) |
| { |
| n++; |
| } |
| } |
| |
| if (n == 0) |
| { |
| throw new ArgumentException("At least 1 collector must not be null"); |
| } |
| else if (n == 1) |
| { |
| // only 1 Collector - return it. |
| ICollector col = null; |
| foreach (ICollector c in collectors) |
| { |
| if (c != null) |
| { |
| col = c; |
| break; |
| } |
| } |
| return col; |
| } |
| else if (n == collectors.Length) |
| { |
| return new MultiCollector(collectors); |
| } |
| else |
| { |
| ICollector[] colls = new ICollector[n]; |
| n = 0; |
| foreach (ICollector c in collectors) |
| { |
| if (c != null) |
| { |
| colls[n++] = c; |
| } |
| } |
| return new MultiCollector(colls); |
| } |
| } |
| |
| private readonly ICollector[] collectors; |
| |
| private MultiCollector(params ICollector[] collectors) |
| { |
| this.collectors = collectors; |
| } |
| |
| public virtual bool AcceptsDocsOutOfOrder |
| { |
| get |
| { |
| foreach (ICollector c in collectors) |
| { |
| if (!c.AcceptsDocsOutOfOrder) |
| { |
| return false; |
| } |
| } |
| return true; |
| } |
| } |
| |
| public virtual void Collect(int doc) |
| { |
| foreach (ICollector c in collectors) |
| { |
| c.Collect(doc); |
| } |
| } |
| |
| public virtual void SetNextReader(AtomicReaderContext context) |
| { |
| foreach (ICollector c in collectors) |
| { |
| c.SetNextReader(context); |
| } |
| } |
| |
| public virtual void SetScorer(Scorer scorer) |
| { |
| foreach (ICollector c in collectors) |
| { |
| c.SetScorer(scorer); |
| } |
| } |
| } |
| } |