IndexFileNames.cs

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/* 
 * 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 System;
using Lucene.Net.Support;

namespace Lucene.Net.Index
{
    
    /// <summary>Useful constants representing filenames and extensions used by lucene</summary>
    public sealed class IndexFileNames
    {
        
        /// <summary>Name of the index segment file </summary>
        public /*internal*/ const System.String SEGMENTS = "segments";
        
        /// <summary>Name of the generation reference file name </summary>
        public /*internal*/ const System.String SEGMENTS_GEN = "segments.gen";
        
        /// <summary>Name of the index deletable file (only used in
        /// pre-lockless indices) 
        /// </summary>
        public /*internal*/ const System.String DELETABLE = "deletable";
        
        /// <summary>Extension of norms file </summary>
        public /*internal*/ const System.String NORMS_EXTENSION = "nrm";
        
        /// <summary>Extension of freq postings file </summary>
        public /*internal*/ const System.String FREQ_EXTENSION = "frq";
        
        /// <summary>Extension of prox postings file </summary>
        public /*internal*/ const System.String PROX_EXTENSION = "prx";
        
        /// <summary>Extension of terms file </summary>
        public /*internal*/ const System.String TERMS_EXTENSION = "tis";
        
        /// <summary>Extension of terms index file </summary>
        public /*internal*/ const System.String TERMS_INDEX_EXTENSION = "tii";
        
        /// <summary>Extension of stored fields index file </summary>
        public /*internal*/ const System.String FIELDS_INDEX_EXTENSION = "fdx";
        
        /// <summary>Extension of stored fields file </summary>
        public /*internal*/ const System.String FIELDS_EXTENSION = "fdt";
        
        /// <summary>Extension of vectors fields file </summary>
        public /*internal*/ const System.String VECTORS_FIELDS_EXTENSION = "tvf";
        
        /// <summary>Extension of vectors documents file </summary>
        public /*internal*/ const System.String VECTORS_DOCUMENTS_EXTENSION = "tvd";
        
        /// <summary>Extension of vectors index file </summary>
        public /*internal*/ const System.String VECTORS_INDEX_EXTENSION = "tvx";
        
        /// <summary>Extension of compound file </summary>
        public /*internal*/ const System.String COMPOUND_FILE_EXTENSION = "cfs";
        
        /// <summary>Extension of compound file for doc store files</summary>
        public /*internal*/ const System.String COMPOUND_FILE_STORE_EXTENSION = "cfx";
        
        /// <summary>Extension of deletes </summary>
        internal const System.String DELETES_EXTENSION = "del";
        
        /// <summary>Extension of field infos </summary>
        public /*internal*/ const System.String FIELD_INFOS_EXTENSION = "fnm";
        
        /// <summary>Extension of plain norms </summary>
        public /*internal*/ const System.String PLAIN_NORMS_EXTENSION = "f";
        
        /// <summary>Extension of separate norms </summary>
        public /*internal*/ const System.String SEPARATE_NORMS_EXTENSION = "s";
        
        /// <summary>Extension of gen file </summary>
        public /*internal*/ const System.String GEN_EXTENSION = "gen";
        
        /// <summary> This array contains all filename extensions used by
        /// Lucene's index files, with two exceptions, namely the
        /// extension made up from <c>.f</c> + a number and
        /// from <c>.s</c> + a number.  Also note that
        /// Lucene's <c>segments_N</c> files do not have any
        /// filename extension.
        /// </summary>
        public /*internal*/ static readonly System.String[] INDEX_EXTENSIONS = new System.String[]{COMPOUND_FILE_EXTENSION, FIELD_INFOS_EXTENSION, FIELDS_INDEX_EXTENSION, FIELDS_EXTENSION, TERMS_INDEX_EXTENSION, TERMS_EXTENSION, FREQ_EXTENSION, PROX_EXTENSION, DELETES_EXTENSION, VECTORS_INDEX_EXTENSION, VECTORS_DOCUMENTS_EXTENSION, VECTORS_FIELDS_EXTENSION, GEN_EXTENSION, NORMS_EXTENSION, COMPOUND_FILE_STORE_EXTENSION};
        
        /// <summary>File extensions that are added to a compound file
        /// (same as above, minus "del", "gen", "cfs"). 
        /// </summary>
        public /*internal*/ static readonly System.String[] INDEX_EXTENSIONS_IN_COMPOUND_FILE = new System.String[]{FIELD_INFOS_EXTENSION, FIELDS_INDEX_EXTENSION, FIELDS_EXTENSION, TERMS_INDEX_EXTENSION, TERMS_EXTENSION, FREQ_EXTENSION, PROX_EXTENSION, VECTORS_INDEX_EXTENSION, VECTORS_DOCUMENTS_EXTENSION, VECTORS_FIELDS_EXTENSION, NORMS_EXTENSION};
        
        public /*internal*/ static readonly System.String[] STORE_INDEX_EXTENSIONS = new System.String[]{VECTORS_INDEX_EXTENSION, VECTORS_FIELDS_EXTENSION, VECTORS_DOCUMENTS_EXTENSION, FIELDS_INDEX_EXTENSION, FIELDS_EXTENSION};
        
        public /*internal*/ static readonly System.String[] NON_STORE_INDEX_EXTENSIONS = new System.String[]{FIELD_INFOS_EXTENSION, FREQ_EXTENSION, PROX_EXTENSION, TERMS_EXTENSION, TERMS_INDEX_EXTENSION, NORMS_EXTENSION};
        
        /// <summary>File extensions of old-style index files </summary>
        public /*internal*/ static readonly System.String[] COMPOUND_EXTENSIONS = new System.String[]{FIELD_INFOS_EXTENSION, FREQ_EXTENSION, PROX_EXTENSION, FIELDS_INDEX_EXTENSION, FIELDS_EXTENSION, TERMS_INDEX_EXTENSION, TERMS_EXTENSION};
        
        /// <summary>File extensions for term vector support </summary>
        public /*internal*/ static readonly System.String[] VECTOR_EXTENSIONS = new System.String[]{VECTORS_INDEX_EXTENSION, VECTORS_DOCUMENTS_EXTENSION, VECTORS_FIELDS_EXTENSION};
        
        /// <summary> Computes the full file name from base, extension and
        /// generation.  If the generation is -1, the file name is
        /// null.  If it's 0, the file name is 
        /// If it's > 0, the file name is 
        /// 
        /// </summary>
        /// <param name="base_Renamed">-- main part of the file name
        /// </param>
        /// <param name="extension">-- extension of the filename (including .)
        /// </param>
        /// <param name="gen">-- generation
        /// </param>
        public /*internal*/ static System.String FileNameFromGeneration(System.String base_Renamed, System.String extension, long gen)
        {
            if (gen == SegmentInfo.NO)
            {
                return null;
            }
            else if (gen == SegmentInfo.WITHOUT_GEN)
            {
                return base_Renamed + extension;
            }
            else
            {
#if !PRE_LUCENE_NET_2_0_0_COMPATIBLE
                return base_Renamed + "_" + Number.ToString(gen) + extension;
#else
                return base_Renamed + "_" + System.Convert.ToString(gen, 16) + extension;
#endif
            }
        }
        
        /// <summary> Returns true if the provided filename is one of the doc
        /// store files (ends with an extension in
        /// STORE_INDEX_EXTENSIONS).
        /// </summary>
        internal static bool IsDocStoreFile(System.String fileName)
        {
            if (fileName.EndsWith(COMPOUND_FILE_STORE_EXTENSION))
                return true;
            for (int i = 0; i < STORE_INDEX_EXTENSIONS.Length; i++)
                if (fileName.EndsWith(STORE_INDEX_EXTENSIONS[i]))
                    return true;
            return false;
        }
        
        internal static System.String SegmentFileName(System.String segmentName, System.String ext)
        {
            return segmentName + "." + ext;
        }
    }
}