| using Lucene.Net.Index; |
| using Lucene.Net.Queries.Function; |
| using Lucene.Net.Search; |
| using Lucene.Net.Support; |
| using System; |
| using System.Collections; |
| using System.Collections.Generic; |
| |
| 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.Queries.Function.ValueSource"/> which evaluates a |
| /// <see cref="Expression"/> given the context of an <see cref="Bindings"/>. |
| /// </summary> |
| internal sealed class ExpressionValueSource : ValueSource |
| { |
| internal readonly ValueSource[] variables; |
| internal readonly Expression expression; |
| internal readonly bool needsScores; |
| |
| internal ExpressionValueSource(Bindings bindings, Expression expression) |
| { |
| if (bindings == null) |
| { |
| throw new ArgumentNullException(); |
| } |
| if (expression == null) |
| { |
| throw new ArgumentNullException(); |
| } |
| this.expression = expression; |
| variables = new ValueSource[expression.Variables.Length]; |
| bool needsScores = false; |
| for (int i = 0; i < variables.Length; i++) |
| { |
| ValueSource source = bindings.GetValueSource(expression.Variables[i]); |
| if (source is ScoreValueSource) |
| { |
| needsScores = true; |
| } |
| else |
| { |
| var valueSource = source as ExpressionValueSource; |
| if (valueSource != null) |
| { |
| if (valueSource.NeedsScores) |
| { |
| needsScores = true; |
| } |
| } |
| else |
| { |
| if (source == null) |
| { |
| throw new InvalidOperationException("Internal error. Variable (" + expression.Variables[i] |
| + ") does not exist."); |
| } |
| } |
| } |
| variables[i] = source; |
| } |
| this.needsScores = needsScores; |
| } |
| |
| public override FunctionValues GetValues(IDictionary context, AtomicReaderContext readerContext) |
| { |
| IDictionary<string, FunctionValues> valuesCache = (IDictionary<string, FunctionValues>)context["valuesCache"]; |
| if (valuesCache == null) |
| { |
| valuesCache = new Dictionary<string, FunctionValues>(); |
| context = new Hashtable(context); |
| context["valuesCache"] = valuesCache; |
| } |
| FunctionValues[] externalValues = new FunctionValues[expression.Variables.Length]; |
| for (int i = 0; i < variables.Length; ++i) |
| { |
| string externalName = expression.Variables[i]; |
| FunctionValues values; |
| if (!valuesCache.TryGetValue(externalName,out values)) |
| { |
| values = variables[i].GetValues(context, readerContext); |
| if (values == null) |
| { |
| throw new InvalidOperationException("Internal error. External (" + externalName + ") does not exist."); |
| } |
| valuesCache[externalName] = values; |
| } |
| externalValues[i] = values; |
| } |
| return new ExpressionFunctionValues(this, expression, externalValues); |
| } |
| |
| public override SortField GetSortField(bool reverse) |
| { |
| return new ExpressionSortField(expression.SourceText, this, reverse); |
| } |
| |
| public override string GetDescription() |
| { |
| return "expr(" + expression.SourceText + ")"; |
| } |
| |
| public override int GetHashCode() |
| { |
| int prime = 31; |
| int result = 1; |
| result = prime * result + ((expression == null) ? 0 : expression.GetHashCode()); |
| result = prime * result + (needsScores ? 1231 : 1237); |
| result = prime * result + Arrays.GetHashCode(variables); |
| return result; |
| } |
| |
| public override bool Equals(object obj) |
| { |
| if (this == obj) |
| { |
| return true; |
| } |
| if (obj == null) |
| { |
| return false; |
| } |
| if (GetType() != obj.GetType()) |
| { |
| return false; |
| } |
| ExpressionValueSource other = (ExpressionValueSource)obj; |
| if (expression == null) |
| { |
| if (other.expression != null) |
| { |
| return false; |
| } |
| } |
| else |
| { |
| if (!expression.Equals(other.expression)) |
| { |
| return false; |
| } |
| } |
| if (needsScores != other.needsScores) |
| { |
| return false; |
| } |
| if (!Arrays.Equals(variables, other.variables)) |
| { |
| return false; |
| } |
| return true; |
| } |
| |
| internal bool NeedsScores => needsScores; |
| } |
| } |