| 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. |
| */ |
| |
| using Directory = Lucene.Net.Store.Directory; |
| |
| /// <summary> |
| /// <para>Expert: represents a single commit into an index as seen by the |
| /// <see cref="IndexDeletionPolicy"/> or <see cref="IndexReader"/>.</para> |
| /// |
| /// <para> Changes to the content of an index are made visible |
| /// only after the writer who made that change commits by |
| /// writing a new segments file |
| /// (<c>segments_N</c>). This point in time, when the |
| /// action of writing of a new segments file to the directory |
| /// is completed, is an index commit.</para> |
| /// |
| /// <para>Each index commit point has a unique segments file |
| /// associated with it. The segments file associated with a |
| /// later index commit point would have a larger N.</para> |
| /// |
| /// @lucene.experimental |
| /// </summary> |
| |
| public abstract class IndexCommit : IComparable<IndexCommit> |
| { |
| /// <summary> |
| /// Get the segments file (<c>segments_N</c>) associated |
| /// with this commit point. |
| /// </summary> |
| public abstract string SegmentsFileName { get; } |
| |
| /// <summary> |
| /// Returns all index files referenced by this commit point. |
| /// </summary> |
| public abstract ICollection<string> FileNames { get; } |
| |
| /// <summary> |
| /// Returns the <see cref="Store.Directory"/> for the index. |
| /// </summary> |
| public abstract Directory Directory { get; } |
| |
| /// <summary> |
| /// Delete this commit point. This only applies when using |
| /// the commit point in the context of <see cref="IndexWriter"/>'s |
| /// <see cref="IndexDeletionPolicy"/>. |
| /// <para/> |
| /// Upon calling this, the writer is notified that this commit |
| /// point should be deleted. |
| /// <para/> |
| /// Decision that a commit-point should be deleted is taken by the <see cref="IndexDeletionPolicy"/> in effect |
| /// and therefore this should only be called by its <see cref="IndexDeletionPolicy.OnInit{T}(IList{T})"/> or |
| /// <see cref="IndexDeletionPolicy.OnCommit{T}(IList{T})"/> methods. |
| /// </summary> |
| public abstract void Delete(); |
| |
| /// <summary> |
| /// Returns <c>true</c> if this commit should be deleted; this is |
| /// only used by <see cref="IndexWriter"/> after invoking the |
| /// <see cref="IndexDeletionPolicy"/>. |
| /// </summary> |
| public abstract bool IsDeleted { get; } |
| |
| /// <summary> |
| /// Returns number of segments referenced by this commit. </summary> |
| public abstract int SegmentCount { get; } |
| |
| /// <summary> |
| /// Sole constructor. (For invocation by subclass |
| /// constructors, typically implicit.) |
| /// </summary> |
| protected IndexCommit() |
| { |
| } |
| |
| /// <summary> |
| /// Two IndexCommits are equal if both their <see cref="Store.Directory"/> and versions are equal. </summary> |
| public override bool Equals(object other) |
| { |
| if (other is IndexCommit otherCommit) |
| { |
| return otherCommit.Directory == Directory && otherCommit.Generation == Generation; |
| } |
| else |
| { |
| return false; |
| } |
| } |
| |
| public override int GetHashCode() |
| { |
| return Directory.GetHashCode() + Generation.GetHashCode(); |
| } |
| |
| /// <summary> |
| /// Returns the generation (the _N in segments_N) for this |
| /// <see cref="IndexCommit"/> |
| /// </summary> |
| public abstract long Generation { get; } |
| |
| /// <summary> |
| /// Returns userData, previously passed to |
| /// <see cref="IndexWriter.SetCommitData(IDictionary{string, string})"/>} for this commit. |
| /// The dictionary is <see cref="string"/> -> <see cref="string"/>. |
| /// </summary> |
| public abstract IDictionary<string, string> UserData { get; } |
| |
| public virtual int CompareTo(IndexCommit commit) |
| { |
| if (Directory != commit.Directory) |
| { |
| throw new NotSupportedException("cannot compare IndexCommits from different Directory instances"); |
| } |
| |
| long gen = Generation; |
| long comgen = commit.Generation; |
| if (gen < comgen) |
| { |
| return -1; |
| } |
| else if (gen > comgen) |
| { |
| return 1; |
| } |
| else |
| { |
| return 0; |
| } |
| } |
| } |
| } |