| using Lucene.Net.Diagnostics; |
| using Lucene.Net.Index; |
| using Lucene.Net.Search; |
| using Lucene.Net.Util; |
| using System.Collections; |
| using System.Collections.Generic; |
| using System.Diagnostics; |
| using System.Text; |
| using JCG = J2N.Collections.Generic; |
| |
| namespace Lucene.Net.Queries |
| { |
| /* |
| * 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> |
| /// A container <see cref="Filter"/> that allows Boolean composition of <see cref="Filter"/>s. |
| /// <see cref="Filter"/>s are allocated into one of three logical constructs; |
| /// SHOULD, MUST NOT, MUST |
| /// The results <see cref="Filter"/> BitSet is constructed as follows: |
| /// SHOULD Filters are OR'd together |
| /// The resulting <see cref="Filter"/> is NOT'd with the NOT <see cref="Filter"/>s |
| /// The resulting <see cref="Filter"/> is AND'd with the MUST <see cref="Filter"/>s |
| /// </summary> |
| public class BooleanFilter : Filter, IEnumerable<FilterClause> |
| { |
| private readonly IList<FilterClause> clauses = new JCG.List<FilterClause>(); |
| |
| /// <summary> |
| /// Returns the a <see cref="DocIdSetIterator"/> representing the Boolean composition |
| /// of the filters that have been added. |
| /// </summary> |
| public override DocIdSet GetDocIdSet(AtomicReaderContext context, IBits acceptDocs) |
| { |
| FixedBitSet res = null; |
| AtomicReader reader = context.AtomicReader; |
| |
| bool hasShouldClauses = false; |
| foreach (FilterClause fc in clauses) |
| { |
| if (fc.Occur == Occur.SHOULD) |
| { |
| hasShouldClauses = true; |
| DocIdSetIterator disi = GetDISI(fc.Filter, context); |
| if (disi == null) |
| { |
| continue; |
| } |
| if (res == null) |
| { |
| res = new FixedBitSet(reader.MaxDoc); |
| } |
| res.Or(disi); |
| } |
| } |
| if (hasShouldClauses && res == null) |
| { |
| return null; |
| } |
| |
| foreach (FilterClause fc in clauses) |
| { |
| if (fc.Occur == Occur.MUST_NOT) |
| { |
| if (res == null) |
| { |
| if (Debugging.AssertsEnabled) Debugging.Assert(!hasShouldClauses); |
| res = new FixedBitSet(reader.MaxDoc); |
| res.Set(0, reader.MaxDoc); // NOTE: may set bits on deleted docs |
| } |
| |
| DocIdSetIterator disi = GetDISI(fc.Filter, context); |
| if (disi != null) |
| { |
| res.AndNot(disi); |
| } |
| } |
| } |
| |
| foreach (FilterClause fc in clauses) |
| { |
| if (fc.Occur == Occur.MUST) |
| { |
| DocIdSetIterator disi = GetDISI(fc.Filter, context); |
| if (disi == null) |
| { |
| return null; // no documents can match |
| } |
| if (res == null) |
| { |
| res = new FixedBitSet(reader.MaxDoc); |
| res.Or(disi); |
| } |
| else |
| { |
| res.And(disi); |
| } |
| } |
| } |
| |
| return BitsFilteredDocIdSet.Wrap(res, acceptDocs); |
| } |
| |
| private static DocIdSetIterator GetDISI(Filter filter, AtomicReaderContext context) |
| { |
| // we dont pass acceptDocs, we will filter at the end using an additional filter |
| DocIdSet set = filter.GetDocIdSet(context, null); |
| return set?.GetIterator(); |
| } |
| |
| /// <summary> |
| /// Adds a new <see cref="FilterClause"/> to the Boolean <see cref="Filter"/> container </summary> |
| /// <param name="filterClause"> A <see cref="FilterClause"/> object containing a <see cref="Filter"/> and an <see cref="Occur"/> parameter </param> |
| public virtual void Add(FilterClause filterClause) |
| { |
| clauses.Add(filterClause); |
| } |
| |
| public void Add(Filter filter, Occur occur) |
| { |
| Add(new FilterClause(filter, occur)); |
| } |
| |
| /// <summary> |
| /// Gets the list of clauses |
| /// </summary> |
| public virtual IList<FilterClause> Clauses => clauses; |
| |
| /// <summary> |
| /// Returns an iterator on the clauses in this query. It implements the <see cref="IEnumerable{T}"/> interface to |
| /// make it possible to do: |
| /// <code>for (FilterClause clause : booleanFilter) {}</code> |
| /// </summary> |
| public IEnumerator<FilterClause> GetEnumerator() |
| { |
| return Clauses.GetEnumerator(); |
| } |
| |
| public override bool Equals(object obj) |
| { |
| if (this == obj) |
| { |
| return true; |
| } |
| |
| if ((obj == null) || (obj.GetType() != this.GetType())) |
| { |
| return false; |
| } |
| |
| var other = (BooleanFilter)obj; |
| return clauses.Equals(other.clauses); |
| } |
| |
| public override int GetHashCode() |
| { |
| return 657153718 ^ clauses.GetHashCode(); |
| } |
| |
| /// <summary> |
| /// Prints a user-readable version of this <see cref="Filter"/>. </summary> |
| public override string ToString() |
| { |
| var buffer = new StringBuilder("BooleanFilter("); |
| int minLen = buffer.Length; |
| foreach (FilterClause c in clauses) |
| { |
| if (buffer.Length > minLen) |
| { |
| buffer.Append(' '); |
| } |
| buffer.Append(c); |
| } |
| return buffer.Append(')').ToString(); |
| } |
| |
| // LUCENENET specific |
| IEnumerator IEnumerable.GetEnumerator() |
| { |
| return GetEnumerator(); |
| } |
| } |
| } |