| using System; |
| using System.Text; |
| |
| 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 AttributeSource = Lucene.Net.Util.AttributeSource; |
| using Automaton = Lucene.Net.Util.Automaton.Automaton; |
| using CompiledAutomaton = Lucene.Net.Util.Automaton.CompiledAutomaton; |
| using Term = Lucene.Net.Index.Term; |
| using Terms = Lucene.Net.Index.Terms; |
| using TermsEnum = Lucene.Net.Index.TermsEnum; |
| using ToStringUtils = Lucene.Net.Util.ToStringUtils; |
| |
| /// <summary> |
| /// A <see cref="Query"/> that will match terms against a finite-state machine. |
| /// <para> |
| /// This query will match documents that contain terms accepted by a given |
| /// finite-state machine. The automaton can be constructed with the |
| /// <see cref="Lucene.Net.Util.Automaton"/> API. Alternatively, it can be |
| /// created from a regular expression with <see cref="RegexpQuery"/> or from |
| /// the standard Lucene wildcard syntax with <see cref="WildcardQuery"/>. |
| /// </para> |
| /// <para> |
| /// When the query is executed, it will create an equivalent DFA of the |
| /// finite-state machine, and will enumerate the term dictionary in an |
| /// intelligent way to reduce the number of comparisons. For example: the regular |
| /// expression of <c>[dl]og?</c> will make approximately four comparisons: |
| /// do, dog, lo, and log. |
| /// </para> |
| /// @lucene.experimental |
| /// </summary> |
| public class AutomatonQuery : MultiTermQuery |
| { |
| /// <summary> |
| /// The automaton to match index terms against </summary> |
| protected readonly Automaton m_automaton; |
| |
| protected readonly CompiledAutomaton m_compiled; |
| |
| /// <summary> |
| /// Term containing the field, and possibly some pattern structure </summary> |
| protected readonly Term m_term; |
| |
| /// <summary> |
| /// Create a new AutomatonQuery from an <see cref="Automaton"/>. |
| /// </summary> |
| /// <param name="term"> <see cref="Term"/> containing field and possibly some pattern structure. The |
| /// term text is ignored. </param> |
| /// <param name="automaton"> <see cref="Automaton"/> to run, terms that are accepted are considered a |
| /// match. </param> |
| public AutomatonQuery(Term term, Automaton automaton) |
| : base(term.Field) |
| { |
| this.m_term = term; |
| this.m_automaton = automaton; |
| this.m_compiled = new CompiledAutomaton(automaton); |
| } |
| |
| protected override TermsEnum GetTermsEnum(Terms terms, AttributeSource atts) |
| { |
| return m_compiled.GetTermsEnum(terms); |
| } |
| |
| public override int GetHashCode() |
| { |
| const int prime = 31; |
| int result = base.GetHashCode(); |
| result = prime * result + m_compiled.GetHashCode(); |
| result = prime * result + ((m_term == null) ? 0 : m_term.GetHashCode()); |
| return result; |
| } |
| |
| public override bool Equals(object obj) |
| { |
| if (this == obj) |
| { |
| return true; |
| } |
| if (!base.Equals(obj)) |
| { |
| return false; |
| } |
| if (this.GetType() != obj.GetType()) |
| { |
| return false; |
| } |
| AutomatonQuery other = (AutomatonQuery)obj; |
| if (!m_compiled.Equals(other.m_compiled)) |
| { |
| return false; |
| } |
| if (m_term == null) |
| { |
| if (other.m_term != null) |
| { |
| return false; |
| } |
| } |
| else if (!m_term.Equals(other.m_term)) |
| { |
| return false; |
| } |
| return true; |
| } |
| |
| public override string ToString(string field) |
| { |
| StringBuilder buffer = new StringBuilder(); |
| if (!m_term.Field.Equals(field, StringComparison.Ordinal)) |
| { |
| buffer.Append(m_term.Field); |
| buffer.Append(":"); |
| } |
| buffer.Append(this.GetType().Name); |
| buffer.Append(" {"); |
| buffer.Append('\n'); |
| buffer.Append(m_automaton.ToString()); |
| buffer.Append("}"); |
| buffer.Append(ToStringUtils.Boost(Boost)); |
| return buffer.ToString(); |
| } |
| |
| /// <summary> |
| /// Returns the automaton used to create this query </summary> |
| public virtual Automaton Automaton => m_automaton; |
| } |
| } |