| using Lucene.Net.Search; |
| using System.Text; |
| |
| namespace Lucene.Net.Expressions |
| { |
| /* |
| * 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 <see cref="Lucene.Net.Search.SortField"/> which sorts documents by the evaluated value of an expression for each document |
| /// </summary> |
| internal class ExpressionSortField : SortField |
| { |
| private readonly ExpressionValueSource source; |
| |
| internal ExpressionSortField(string name, ExpressionValueSource source, bool reverse) |
| : base(name, SortFieldType.CUSTOM, reverse) |
| { |
| this.source = source; |
| } |
| |
| public override FieldComparer GetComparer(int numHits, int sortPos) |
| { |
| return new ExpressionComparer(source, numHits); |
| } |
| |
| public override int GetHashCode() |
| { |
| int prime = 31; |
| int result = base.GetHashCode(); |
| result = prime * result + ((source == null) ? 0 : source.GetHashCode()); |
| return result; |
| } |
| |
| public override bool Equals(object obj) |
| { |
| if (this == obj) |
| { |
| return true; |
| } |
| if (!base.Equals(obj)) |
| { |
| return false; |
| } |
| if (GetType() != obj.GetType()) |
| { |
| return false; |
| } |
| ExpressionSortField other = (ExpressionSortField)obj; |
| if (source == null) |
| { |
| if (other.source != null) |
| { |
| return false; |
| } |
| } |
| else |
| { |
| if (!source.Equals(other.source)) |
| { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| public override string ToString() |
| { |
| StringBuilder buffer = new StringBuilder(); |
| buffer.Append("<expr \""); |
| buffer.Append(Field); |
| buffer.Append("\">"); |
| if (IsReverse) |
| { |
| buffer.Append('!'); |
| } |
| return buffer.ToString(); |
| } |
| |
| public override bool NeedsScores => source.NeedsScores; |
| } |
| } |