| using Lucene.Net.Index; |
| using Lucene.Net.Util; |
| using System.Text; |
| |
| namespace Lucene.Net.QueryParsers.Surround.Query |
| { |
| /* |
| * 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> |
| /// Query that matches string prefixes |
| /// </summary> |
| public class SrndPrefixQuery : SimpleTerm |
| { |
| private readonly BytesRef prefixRef; |
| public SrndPrefixQuery(string prefix, bool quoted, char truncator) |
| : base(quoted) |
| { |
| this.prefix = prefix; |
| prefixRef = new BytesRef(prefix); |
| this.truncator = truncator; |
| } |
| |
| private readonly string prefix; |
| public virtual string Prefix => prefix; |
| |
| private readonly char truncator; |
| public virtual char SuffixOperator => truncator; |
| |
| public virtual Term GetLucenePrefixTerm(string fieldName) |
| { |
| return new Term(fieldName, Prefix); |
| } |
| |
| public override string ToStringUnquoted() |
| { |
| return Prefix; |
| } |
| |
| protected override void SuffixToString(StringBuilder r) |
| { |
| r.Append(SuffixOperator); |
| } |
| |
| public override void VisitMatchingTerms(IndexReader reader, string fieldName, IMatchingTermVisitor mtv) |
| { |
| /* inspired by PrefixQuery.rewrite(): */ |
| Terms terms = MultiFields.GetTerms(reader, fieldName); |
| if (terms != null) |
| { |
| TermsEnum termsEnum = terms.GetEnumerator(); |
| |
| bool skip = false; |
| TermsEnum.SeekStatus status = termsEnum.SeekCeil(new BytesRef(Prefix)); |
| if (status == TermsEnum.SeekStatus.FOUND) |
| { |
| mtv.VisitMatchingTerm(GetLucenePrefixTerm(fieldName)); |
| } |
| else if (status == TermsEnum.SeekStatus.NOT_FOUND) |
| { |
| if (StringHelper.StartsWith(termsEnum.Term, prefixRef)) |
| { |
| mtv.VisitMatchingTerm(new Term(fieldName, termsEnum.Term.Utf8ToString())); |
| } |
| else |
| { |
| skip = true; |
| } |
| } |
| else |
| { |
| // EOF |
| skip = true; |
| } |
| |
| if (!skip) |
| { |
| while (termsEnum.MoveNext()) |
| { |
| BytesRef text = termsEnum.Term; |
| if (StringHelper.StartsWith(text, prefixRef)) |
| mtv.VisitMatchingTerm(new Term(fieldName, text.Utf8ToString())); |
| else |
| break; |
| } |
| } |
| } |
| } |
| } |
| } |