| using Lucene.Net.Index; |
| 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. |
| */ |
| |
| /// <summary> |
| /// Randomize collection order. Don't forget to call <see cref="Flush()"/> when |
| /// collection is finished to collect buffered documents. |
| /// </summary> |
| internal sealed class RandomOrderCollector : ICollector |
| { |
| internal readonly Random random; |
| internal readonly ICollector @in; |
| internal Scorer scorer; |
| internal FakeScorer fakeScorer; |
| |
| internal int buffered; |
| internal readonly int bufferSize; |
| internal readonly int[] docIDs; |
| internal readonly float[] scores; |
| internal readonly int[] freqs; |
| |
| internal RandomOrderCollector(Random random, ICollector @in) |
| { |
| if (!@in.AcceptsDocsOutOfOrder) |
| { |
| throw new ArgumentException(); |
| } |
| this.@in = @in; |
| this.random = random; |
| bufferSize = 1 + random.Next(100); |
| docIDs = new int[bufferSize]; |
| scores = new float[bufferSize]; |
| freqs = new int[bufferSize]; |
| buffered = 0; |
| } |
| |
| public void SetScorer(Scorer scorer) |
| { |
| this.scorer = scorer; |
| fakeScorer = new FakeScorer(); |
| @in.SetScorer(fakeScorer); |
| } |
| |
| private void Shuffle() |
| { |
| for (int i = buffered - 1; i > 0; --i) |
| { |
| int other = random.Next(i + 1); |
| |
| int tmpDoc = docIDs[i]; |
| docIDs[i] = docIDs[other]; |
| docIDs[other] = tmpDoc; |
| |
| float tmpScore = scores[i]; |
| scores[i] = scores[other]; |
| scores[other] = tmpScore; |
| |
| int tmpFreq = freqs[i]; |
| freqs[i] = freqs[other]; |
| freqs[other] = tmpFreq; |
| } |
| } |
| |
| public void Flush() |
| { |
| Shuffle(); |
| for (int i = 0; i < buffered; ++i) |
| { |
| fakeScorer.doc = docIDs[i]; |
| fakeScorer.freq = freqs[i]; |
| fakeScorer.score = scores[i]; |
| @in.Collect(fakeScorer.DocID); |
| } |
| buffered = 0; |
| } |
| |
| public void Collect(int doc) |
| { |
| docIDs[buffered] = doc; |
| scores[buffered] = scorer.GetScore(); |
| try |
| { |
| freqs[buffered] = scorer.Freq; |
| } |
| catch (NotSupportedException) |
| { |
| freqs[buffered] = -1; |
| } |
| if (++buffered == bufferSize) |
| { |
| Flush(); |
| } |
| } |
| |
| public bool AcceptsDocsOutOfOrder |
| => @in.AcceptsDocsOutOfOrder; |
| |
| public void SetNextReader(AtomicReaderContext context) |
| => throw new NotSupportedException(); |
| } |
| } |