| using System; |
| using System.Collections.Generic; |
| |
| namespace Lucene.Net.Index |
| { |
| /* |
| * 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 struct like class that represents a hierarchical relationship between |
| /// <see cref="IndexReader"/> instances. |
| /// </summary> |
| public abstract class IndexReaderContext |
| { |
| /// <summary> |
| /// The reader context for this reader's immediate parent, or null if none </summary> |
| public CompositeReaderContext Parent { get; private set; } |
| |
| /// <summary> |
| /// <c>true</c> if this context struct represents the top level reader within the hierarchical context </summary> |
| public bool IsTopLevel { get; private set; } |
| |
| /// <summary> |
| /// the doc base for this reader in the parent, <c>0</c> if parent is <c>null</c> </summary> |
| public int DocBaseInParent { get; private set; } |
| |
| /// <summary> |
| /// the ord for this reader in the parent, <c>0</c> if parent is <c>null</c> </summary> |
| public int OrdInParent { get; private set; } |
| |
| internal IndexReaderContext(CompositeReaderContext parent, int ordInParent, int docBaseInParent) |
| { |
| if (!(this is CompositeReaderContext || this is AtomicReaderContext)) |
| { |
| throw new Exception("this class should never be extended by custom code!"); |
| } |
| this.Parent = parent; |
| this.DocBaseInParent = docBaseInParent; |
| this.OrdInParent = ordInParent; |
| this.IsTopLevel = parent == null; |
| } |
| |
| /// <summary> |
| /// Returns the <see cref="IndexReader"/>, this context represents. </summary> |
| public abstract IndexReader Reader { get; } |
| |
| /// <summary> |
| /// Returns the context's leaves if this context is a top-level context. |
| /// For convenience, if this is an <see cref="AtomicReaderContext"/> this |
| /// returns itself as the only leaf. |
| /// <para/>Note: this is convenience method since leaves can always be obtained by |
| /// walking the context tree using <see cref="Children"/>. </summary> |
| /// <exception cref="InvalidOperationException"> if this is not a top-level context. </exception> |
| /// <seealso cref="Children"/> |
| public abstract IList<AtomicReaderContext> Leaves { get; } |
| |
| /// <summary> |
| /// Returns the context's children iff this context is a composite context |
| /// otherwise <c>null</c>. |
| /// </summary> |
| public abstract IList<IndexReaderContext> Children { get; } |
| } |
| } |