| using Lucene.Net.Diagnostics; |
| using System.Collections.Generic; |
| |
| 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> |
| /// Base class for <see cref="Scorer"/>s that score disjunctions. |
| /// Currently this just provides helper methods to manage the heap. |
| /// </summary> |
| internal abstract class DisjunctionScorer : Scorer |
| { |
| protected readonly Scorer[] m_subScorers; |
| |
| /// <summary> |
| /// The document number of the current match. </summary> |
| protected int m_doc = -1; |
| |
| protected int m_numScorers; |
| |
| protected DisjunctionScorer(Weight weight, Scorer[] subScorers) |
| : base(weight) |
| { |
| this.m_subScorers = subScorers; |
| this.m_numScorers = subScorers.Length; |
| Heapify(); |
| } |
| |
| /// <summary> |
| /// Organize subScorers into a min heap with scorers generating the earliest document on top. |
| /// </summary> |
| protected void Heapify() |
| { |
| for (int i = (m_numScorers >> 1) - 1; i >= 0; i--) |
| { |
| HeapAdjust(i); |
| } |
| } |
| |
| /// <summary> |
| /// The subtree of subScorers at root is a min heap except possibly for its root element. |
| /// Bubble the root down as required to make the subtree a heap. |
| /// </summary> |
| protected void HeapAdjust(int root) |
| { |
| Scorer scorer = m_subScorers[root]; |
| int doc = scorer.DocID; |
| int i = root; |
| while (i <= (m_numScorers >> 1) - 1) |
| { |
| int lchild = (i << 1) + 1; |
| Scorer lscorer = m_subScorers[lchild]; |
| int ldoc = lscorer.DocID; |
| int rdoc = int.MaxValue, rchild = (i << 1) + 2; |
| Scorer rscorer = null; |
| if (rchild < m_numScorers) |
| { |
| rscorer = m_subScorers[rchild]; |
| rdoc = rscorer.DocID; |
| } |
| if (ldoc < doc) |
| { |
| if (rdoc < ldoc) |
| { |
| m_subScorers[i] = rscorer; |
| m_subScorers[rchild] = scorer; |
| i = rchild; |
| } |
| else |
| { |
| m_subScorers[i] = lscorer; |
| m_subScorers[lchild] = scorer; |
| i = lchild; |
| } |
| } |
| else if (rdoc < doc) |
| { |
| m_subScorers[i] = rscorer; |
| m_subScorers[rchild] = scorer; |
| i = rchild; |
| } |
| else |
| { |
| return; |
| } |
| } |
| } |
| |
| /// <summary> |
| /// Remove the root <see cref="Scorer"/> from subScorers and re-establish it as a heap |
| /// </summary> |
| protected void HeapRemoveRoot() |
| { |
| if (m_numScorers == 1) |
| { |
| m_subScorers[0] = null; |
| m_numScorers = 0; |
| } |
| else |
| { |
| m_subScorers[0] = m_subScorers[m_numScorers - 1]; |
| m_subScorers[m_numScorers - 1] = null; |
| --m_numScorers; |
| HeapAdjust(0); |
| } |
| } |
| |
| public override sealed ICollection<ChildScorer> GetChildren() |
| { |
| List<ChildScorer> children = new List<ChildScorer>(m_numScorers); |
| for (int i = 0; i < m_numScorers; i++) |
| { |
| children.Add(new ChildScorer(m_subScorers[i], "SHOULD")); |
| } |
| return children; |
| } |
| |
| public override long GetCost() |
| { |
| long sum = 0; |
| for (int i = 0; i < m_numScorers; i++) |
| { |
| sum += m_subScorers[i].GetCost(); |
| } |
| return sum; |
| } |
| |
| public override int DocID => m_doc; |
| |
| public override int NextDoc() |
| { |
| if (Debugging.AssertsEnabled) Debugging.Assert(m_doc != NO_MORE_DOCS); |
| while (true) |
| { |
| if (m_subScorers[0].NextDoc() != NO_MORE_DOCS) |
| { |
| HeapAdjust(0); |
| } |
| else |
| { |
| HeapRemoveRoot(); |
| if (m_numScorers == 0) |
| { |
| return m_doc = NO_MORE_DOCS; |
| } |
| } |
| if (m_subScorers[0].DocID != m_doc) |
| { |
| AfterNext(); |
| return m_doc; |
| } |
| } |
| } |
| |
| public override int Advance(int target) |
| { |
| if (Debugging.AssertsEnabled) Debugging.Assert(m_doc != NO_MORE_DOCS); |
| while (true) |
| { |
| if (m_subScorers[0].Advance(target) != NO_MORE_DOCS) |
| { |
| HeapAdjust(0); |
| } |
| else |
| { |
| HeapRemoveRoot(); |
| if (m_numScorers == 0) |
| { |
| return m_doc = NO_MORE_DOCS; |
| } |
| } |
| if (m_subScorers[0].DocID >= target) |
| { |
| AfterNext(); |
| return m_doc; |
| } |
| } |
| } |
| |
| /// <summary> |
| /// Called after <see cref="NextDoc()"/> or <see cref="Advance(int)"/> land on a new document. |
| /// <para/> |
| /// <c>subScorers[0]</c> will be positioned to the new docid, |
| /// which could be <c>NO_MORE_DOCS</c> (subclass must handle this). |
| /// <para/> |
| /// Implementations should assign <c>doc</c> appropriately, and do any |
| /// other work necessary to implement <see cref="Scorer.GetScore()"/> and <see cref="Index.DocsEnum.Freq"/> |
| /// </summary> |
| // TODO: make this less horrible |
| protected abstract void AfterNext(); |
| } |
| } |