src/Lucene.Net/Codecs/Lucene3x/Lucene3xSegmentInfoReader.cs - lucenenet - Git at Google

 using J2N.Collections.Generic.Extensions;
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Globalization;
 using JCG = J2N.Collections.Generic;
 using CompoundFileDirectory = Lucene.Net.Store.CompoundFileDirectory;
 using Directory = Lucene.Net.Store.Directory;

 namespace Lucene.Net.Codecs.Lucene3x
 {
     /*
      * 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 IndexFileNames = Lucene.Net.Index.IndexFileNames;
     using IndexFormatTooNewException = Lucene.Net.Index.IndexFormatTooNewException;
     using IndexFormatTooOldException = Lucene.Net.Index.IndexFormatTooOldException;
     using IndexInput = Lucene.Net.Store.IndexInput;
     using IOContext = Lucene.Net.Store.IOContext;
     using IOUtils = Lucene.Net.Util.IOUtils;
     using SegmentCommitInfo = Lucene.Net.Index.SegmentCommitInfo;
     using SegmentInfo = Lucene.Net.Index.SegmentInfo;
     using SegmentInfos = Lucene.Net.Index.SegmentInfos;

     /// <summary>
     /// Lucene 3x implementation of <see cref="SegmentInfoReader"/>.
     /// <para/>
     /// @lucene.experimental
     /// </summary>
     [Obsolete("Only for reading existing 3.x indexes")]
     public class Lucene3xSegmentInfoReader : SegmentInfoReader
     {
         public static void ReadLegacyInfos(SegmentInfos infos, Directory directory, IndexInput input, int format)
         {
             infos.Version = input.ReadInt64(); // read version
             infos.Counter = input.ReadInt32(); // read counter
             Lucene3xSegmentInfoReader reader = new Lucene3xSegmentInfoReader();
             for (int i = input.ReadInt32(); i > 0; i--) // read segmentInfos
             {
                 SegmentCommitInfo siPerCommit = reader.ReadLegacySegmentInfo(directory, format, input);
                 SegmentInfo si = siPerCommit.Info;

                 if (si.Version == null)
                 {
                     // Could be a 3.0 - try to open the doc stores - if it fails, it's a
                     // 2.x segment, and an IndexFormatTooOldException will be thrown,
                     // which is what we want.
                     Directory dir = directory;
                     if (Lucene3xSegmentInfoFormat.GetDocStoreOffset(si) != -1)
                     {
                         if (Lucene3xSegmentInfoFormat.GetDocStoreIsCompoundFile(si))
                         {
                             dir = new CompoundFileDirectory(dir, IndexFileNames.SegmentFileName(Lucene3xSegmentInfoFormat.GetDocStoreSegment(si), "", Lucene3xCodec.COMPOUND_FILE_STORE_EXTENSION), IOContext.READ_ONCE, false);
                         }
                     }
                     else if (si.UseCompoundFile)
                     {
                         dir = new CompoundFileDirectory(dir, IndexFileNames.SegmentFileName(si.Name, "", IndexFileNames.COMPOUND_FILE_EXTENSION), IOContext.READ_ONCE, false);
                     }

                     try
                     {
                         Lucene3xStoredFieldsReader.CheckCodeVersion(dir, Lucene3xSegmentInfoFormat.GetDocStoreSegment(si));
                     }
                     finally
                     {
                         // If we opened the directory, close it
                         if (dir != directory)
                         {
                             dir.Dispose();
                         }
                     }

                     // Above call succeeded, so it's a 3.0 segment. Upgrade it so the next
                     // time the segment is read, its version won't be null and we won't
                     // need to open FieldsReader every time for each such segment.
                     si.Version = "3.0";
                 }
                 else if (si.Version.Equals("2.x", StringComparison.Ordinal))
                 {
                     // If it's a 3x index touched by 3.1+ code, then segments record their
                     // version, whether they are 2.x ones or not. We detect that and throw
                     // appropriate exception.
                     throw new IndexFormatTooOldException("segment " + si.Name + " in resource " + input, si.Version);
                 }
                 infos.Add(siPerCommit);
             }

             infos.UserData = input.ReadStringStringMap();
         }

         public override SegmentInfo Read(Directory directory, string segmentName, IOContext context)
         {
             // NOTE: this is NOT how 3.x is really written...
             string fileName = IndexFileNames.SegmentFileName(segmentName, "", Lucene3xSegmentInfoFormat.UPGRADED_SI_EXTENSION);

             bool success = false;

             IndexInput input = directory.OpenInput(fileName, context);

             try
             {
                 SegmentInfo si = ReadUpgradedSegmentInfo(segmentName, directory, input);
                 success = true;
                 return si;
             }
             finally
             {
                 if (!success)
                 {
                     IOUtils.DisposeWhileHandlingException(input);
                 }
                 else
                 {
                     input.Dispose();
                 }
             }
         }

         private static void AddIfExists(Directory dir, ISet<string> files, string fileName)
         {
             if (dir.FileExists(fileName))
             {
                 files.Add(fileName);
             }
         }

         /// <summary>
         /// Reads from legacy 3.x segments_N. </summary>
         private SegmentCommitInfo ReadLegacySegmentInfo(Directory dir, int format, IndexInput input)
         {
             // check that it is a format we can understand
             if (format > Lucene3xSegmentInfoFormat.FORMAT_DIAGNOSTICS)
             {
                 throw new IndexFormatTooOldException(input, format, Lucene3xSegmentInfoFormat.FORMAT_DIAGNOSTICS, Lucene3xSegmentInfoFormat.FORMAT_3_1);
             }
             if (format < Lucene3xSegmentInfoFormat.FORMAT_3_1)
             {
                 throw new IndexFormatTooNewException(input, format, Lucene3xSegmentInfoFormat.FORMAT_DIAGNOSTICS, Lucene3xSegmentInfoFormat.FORMAT_3_1);
             }
             string version;
             if (format <= Lucene3xSegmentInfoFormat.FORMAT_3_1)
             {
                 version = input.ReadString();
             }
             else
             {
                 version = null;
             }

             string name = input.ReadString();

             int docCount = input.ReadInt32();
             long delGen = input.ReadInt64();

             int docStoreOffset = input.ReadInt32();
             IDictionary<string, string> attributes = new Dictionary<string, string>();

             // parse the docstore stuff and shove it into attributes
             string docStoreSegment;
             bool docStoreIsCompoundFile;
             if (docStoreOffset != -1)
             {
                 docStoreSegment = input.ReadString();
                 docStoreIsCompoundFile = input.ReadByte() == SegmentInfo.YES;
                 attributes[Lucene3xSegmentInfoFormat.DS_OFFSET_KEY] = Convert.ToString(docStoreOffset, CultureInfo.InvariantCulture);
                 attributes[Lucene3xSegmentInfoFormat.DS_NAME_KEY] = docStoreSegment;
                 attributes[Lucene3xSegmentInfoFormat.DS_COMPOUND_KEY] = Convert.ToString(docStoreIsCompoundFile, CultureInfo.InvariantCulture);
             }
             else
             {
                 docStoreSegment = name;
                 docStoreIsCompoundFile = false;
             }

             // pre-4.0 indexes write a byte if there is a single norms file
             byte b = input.ReadByte();

             //System.out.println("version=" + version + " name=" + name + " docCount=" + docCount + " delGen=" + delGen + " dso=" + docStoreOffset + " dss=" + docStoreSegment + " dssCFs=" + docStoreIsCompoundFile + " b=" + b + " format=" + format);

             Debug.Assert(1 == b, "expected 1 but was: " + b + " format: " + format);
             int numNormGen = input.ReadInt32();
             IDictionary<int, long> normGen;
             if (numNormGen == SegmentInfo.NO)
             {
                 normGen = null;
             }
             else
             {
                 normGen = new Dictionary<int, long>();
                 for (int j = 0; j < numNormGen; j++)
                 {
                     normGen[j] = input.ReadInt64();
                 }
             }
             bool isCompoundFile = input.ReadByte() == SegmentInfo.YES;

             int delCount = input.ReadInt32();
             Debug.Assert(delCount <= docCount);

             bool hasProx = input.ReadByte() == 1;

             IDictionary<string, string> diagnostics = input.ReadStringStringMap();

             if (format <= Lucene3xSegmentInfoFormat.FORMAT_HAS_VECTORS)
             {
                 // NOTE: unused
                 int hasVectors = input.ReadByte();
             }

             // Replicate logic from 3.x's SegmentInfo.files():
             ISet<string> files = new JCG.HashSet<string>();
             if (isCompoundFile)
             {
                 files.Add(IndexFileNames.SegmentFileName(name, "", IndexFileNames.COMPOUND_FILE_EXTENSION));
             }
             else
             {
                 AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xFieldInfosReader.FIELD_INFOS_EXTENSION));
                 AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xPostingsFormat.FREQ_EXTENSION));
                 AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xPostingsFormat.PROX_EXTENSION));
                 AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xPostingsFormat.TERMS_EXTENSION));
                 AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xPostingsFormat.TERMS_INDEX_EXTENSION));
                 AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xNormsProducer.NORMS_EXTENSION));
             }

             if (docStoreOffset != -1)
             {
                 if (docStoreIsCompoundFile)
                 {
                     files.Add(IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xCodec.COMPOUND_FILE_STORE_EXTENSION));
                 }
                 else
                 {
                     files.Add(IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xStoredFieldsReader.FIELDS_INDEX_EXTENSION));
                     files.Add(IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xStoredFieldsReader.FIELDS_EXTENSION));
                     AddIfExists(dir, files, IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xTermVectorsReader.VECTORS_INDEX_EXTENSION));
                     AddIfExists(dir, files, IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xTermVectorsReader.VECTORS_FIELDS_EXTENSION));
                     AddIfExists(dir, files, IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xTermVectorsReader.VECTORS_DOCUMENTS_EXTENSION));
                 }
             }
             else if (!isCompoundFile)
             {
                 files.Add(IndexFileNames.SegmentFileName(name, "", Lucene3xStoredFieldsReader.FIELDS_INDEX_EXTENSION));
                 files.Add(IndexFileNames.SegmentFileName(name, "", Lucene3xStoredFieldsReader.FIELDS_EXTENSION));
                 AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xTermVectorsReader.VECTORS_INDEX_EXTENSION));
                 AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xTermVectorsReader.VECTORS_FIELDS_EXTENSION));
                 AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xTermVectorsReader.VECTORS_DOCUMENTS_EXTENSION));
             }

             // parse the normgen stuff and shove it into attributes
             if (normGen != null)
             {
                 attributes[Lucene3xSegmentInfoFormat.NORMGEN_KEY] = Convert.ToString(numNormGen, CultureInfo.InvariantCulture);
                 foreach (KeyValuePair<int, long> ent in normGen)
                 {
                     long gen = ent.Value;
                     if (gen >= SegmentInfo.YES)
                     {
                         // Definitely a separate norm file, with generation:
                         files.Add(IndexFileNames.FileNameFromGeneration(name, "s" + ent.Key, gen));
                         attributes[Lucene3xSegmentInfoFormat.NORMGEN_PREFIX + ent.Key] = Convert.ToString(gen, CultureInfo.InvariantCulture);
                     }
                     else if (gen == SegmentInfo.NO)
                     {
                         // No separate norm
                     }
                     else
                     {
                         // We should have already hit indexformat too old exception
                         Debug.Assert(false);
                     }
                 }
             }

             SegmentInfo info = new SegmentInfo(dir, version, name, docCount, isCompoundFile, null, diagnostics, attributes.AsReadOnly());
             info.SetFiles(files);

             SegmentCommitInfo infoPerCommit = new SegmentCommitInfo(info, delCount, delGen, -1);
             return infoPerCommit;
         }

         private SegmentInfo ReadUpgradedSegmentInfo(string name, Directory dir, IndexInput input)
         {
             CodecUtil.CheckHeader(input, Lucene3xSegmentInfoFormat.UPGRADED_SI_CODEC_NAME, Lucene3xSegmentInfoFormat.UPGRADED_SI_VERSION_START, Lucene3xSegmentInfoFormat.UPGRADED_SI_VERSION_CURRENT);
             string version = input.ReadString();

             int docCount = input.ReadInt32();

             IDictionary<string, string> attributes = input.ReadStringStringMap();

             bool isCompoundFile = input.ReadByte() == SegmentInfo.YES;

             IDictionary<string, string> diagnostics = input.ReadStringStringMap();

             ISet<string> files = input.ReadStringSet();

             SegmentInfo info = new SegmentInfo(dir, version, name, docCount, isCompoundFile, null, diagnostics, attributes.AsReadOnly());
             info.SetFiles(files);
             return info;
         }
     }
 }
	using J2N.Collections.Generic.Extensions;
	using System;
	using System.Collections.Generic;
	using System.Diagnostics;
	using System.Globalization;
	using JCG = J2N.Collections.Generic;
	using CompoundFileDirectory = Lucene.Net.Store.CompoundFileDirectory;
	using Directory = Lucene.Net.Store.Directory;

	namespace Lucene.Net.Codecs.Lucene3x
	{
	/*
	* 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 IndexFileNames = Lucene.Net.Index.IndexFileNames;
	using IndexFormatTooNewException = Lucene.Net.Index.IndexFormatTooNewException;
	using IndexFormatTooOldException = Lucene.Net.Index.IndexFormatTooOldException;
	using IndexInput = Lucene.Net.Store.IndexInput;
	using IOContext = Lucene.Net.Store.IOContext;
	using IOUtils = Lucene.Net.Util.IOUtils;
	using SegmentCommitInfo = Lucene.Net.Index.SegmentCommitInfo;
	using SegmentInfo = Lucene.Net.Index.SegmentInfo;
	using SegmentInfos = Lucene.Net.Index.SegmentInfos;

	/// <summary>
	/// Lucene 3x implementation of <see cref="SegmentInfoReader"/>.
	/// <para/>
	/// @lucene.experimental
	/// </summary>
	[Obsolete("Only for reading existing 3.x indexes")]
	public class Lucene3xSegmentInfoReader : SegmentInfoReader
	{
	public static void ReadLegacyInfos(SegmentInfos infos, Directory directory, IndexInput input, int format)
	{
	infos.Version = input.ReadInt64(); // read version
	infos.Counter = input.ReadInt32(); // read counter
	Lucene3xSegmentInfoReader reader = new Lucene3xSegmentInfoReader();
	for (int i = input.ReadInt32(); i > 0; i--) // read segmentInfos
	{
	SegmentCommitInfo siPerCommit = reader.ReadLegacySegmentInfo(directory, format, input);
	SegmentInfo si = siPerCommit.Info;

	if (si.Version == null)
	{
	// Could be a 3.0 - try to open the doc stores - if it fails, it's a
	// 2.x segment, and an IndexFormatTooOldException will be thrown,
	// which is what we want.
	Directory dir = directory;
	if (Lucene3xSegmentInfoFormat.GetDocStoreOffset(si) != -1)
	{
	if (Lucene3xSegmentInfoFormat.GetDocStoreIsCompoundFile(si))
	{
	dir = new CompoundFileDirectory(dir, IndexFileNames.SegmentFileName(Lucene3xSegmentInfoFormat.GetDocStoreSegment(si), "", Lucene3xCodec.COMPOUND_FILE_STORE_EXTENSION), IOContext.READ_ONCE, false);
	}
	}
	else if (si.UseCompoundFile)
	{
	dir = new CompoundFileDirectory(dir, IndexFileNames.SegmentFileName(si.Name, "", IndexFileNames.COMPOUND_FILE_EXTENSION), IOContext.READ_ONCE, false);
	}

	try
	{
	Lucene3xStoredFieldsReader.CheckCodeVersion(dir, Lucene3xSegmentInfoFormat.GetDocStoreSegment(si));
	}
	finally
	{
	// If we opened the directory, close it
	if (dir != directory)
	{
	dir.Dispose();
	}
	}

	// Above call succeeded, so it's a 3.0 segment. Upgrade it so the next
	// time the segment is read, its version won't be null and we won't
	// need to open FieldsReader every time for each such segment.
	si.Version = "3.0";
	}
	else if (si.Version.Equals("2.x", StringComparison.Ordinal))
	{
	// If it's a 3x index touched by 3.1+ code, then segments record their
	// version, whether they are 2.x ones or not. We detect that and throw
	// appropriate exception.
	throw new IndexFormatTooOldException("segment " + si.Name + " in resource " + input, si.Version);
	}
	infos.Add(siPerCommit);
	}

	infos.UserData = input.ReadStringStringMap();
	}

	public override SegmentInfo Read(Directory directory, string segmentName, IOContext context)
	{
	// NOTE: this is NOT how 3.x is really written...
	string fileName = IndexFileNames.SegmentFileName(segmentName, "", Lucene3xSegmentInfoFormat.UPGRADED_SI_EXTENSION);

	bool success = false;

	IndexInput input = directory.OpenInput(fileName, context);

	try
	{
	SegmentInfo si = ReadUpgradedSegmentInfo(segmentName, directory, input);
	success = true;
	return si;
	}
	finally
	{
	if (!success)
	{
	IOUtils.DisposeWhileHandlingException(input);
	}
	else
	{
	input.Dispose();
	}
	}
	}

	private static void AddIfExists(Directory dir, ISet<string> files, string fileName)
	{
	if (dir.FileExists(fileName))
	{
	files.Add(fileName);
	}
	}

	/// <summary>
	/// Reads from legacy 3.x segments_N. </summary>
	private SegmentCommitInfo ReadLegacySegmentInfo(Directory dir, int format, IndexInput input)
	{
	// check that it is a format we can understand
	if (format > Lucene3xSegmentInfoFormat.FORMAT_DIAGNOSTICS)
	{
	throw new IndexFormatTooOldException(input, format, Lucene3xSegmentInfoFormat.FORMAT_DIAGNOSTICS, Lucene3xSegmentInfoFormat.FORMAT_3_1);
	}
	if (format < Lucene3xSegmentInfoFormat.FORMAT_3_1)
	{
	throw new IndexFormatTooNewException(input, format, Lucene3xSegmentInfoFormat.FORMAT_DIAGNOSTICS, Lucene3xSegmentInfoFormat.FORMAT_3_1);
	}
	string version;
	if (format <= Lucene3xSegmentInfoFormat.FORMAT_3_1)
	{
	version = input.ReadString();
	}
	else
	{
	version = null;
	}

	string name = input.ReadString();

	int docCount = input.ReadInt32();
	long delGen = input.ReadInt64();

	int docStoreOffset = input.ReadInt32();
	IDictionary<string, string> attributes = new Dictionary<string, string>();

	// parse the docstore stuff and shove it into attributes
	string docStoreSegment;
	bool docStoreIsCompoundFile;
	if (docStoreOffset != -1)
	{
	docStoreSegment = input.ReadString();
	docStoreIsCompoundFile = input.ReadByte() == SegmentInfo.YES;
	attributes[Lucene3xSegmentInfoFormat.DS_OFFSET_KEY] = Convert.ToString(docStoreOffset, CultureInfo.InvariantCulture);
	attributes[Lucene3xSegmentInfoFormat.DS_NAME_KEY] = docStoreSegment;
	attributes[Lucene3xSegmentInfoFormat.DS_COMPOUND_KEY] = Convert.ToString(docStoreIsCompoundFile, CultureInfo.InvariantCulture);
	}
	else
	{
	docStoreSegment = name;
	docStoreIsCompoundFile = false;
	}

	// pre-4.0 indexes write a byte if there is a single norms file
	byte b = input.ReadByte();

	//System.out.println("version=" + version + " name=" + name + " docCount=" + docCount + " delGen=" + delGen + " dso=" + docStoreOffset + " dss=" + docStoreSegment + " dssCFs=" + docStoreIsCompoundFile + " b=" + b + " format=" + format);

	Debug.Assert(1 == b, "expected 1 but was: " + b + " format: " + format);
	int numNormGen = input.ReadInt32();
	IDictionary<int, long> normGen;
	if (numNormGen == SegmentInfo.NO)
	{
	normGen = null;
	}
	else
	{
	normGen = new Dictionary<int, long>();
	for (int j = 0; j < numNormGen; j++)
	{
	normGen[j] = input.ReadInt64();
	}
	}
	bool isCompoundFile = input.ReadByte() == SegmentInfo.YES;

	int delCount = input.ReadInt32();
	Debug.Assert(delCount <= docCount);

	bool hasProx = input.ReadByte() == 1;

	IDictionary<string, string> diagnostics = input.ReadStringStringMap();

	if (format <= Lucene3xSegmentInfoFormat.FORMAT_HAS_VECTORS)
	{
	// NOTE: unused
	int hasVectors = input.ReadByte();
	}

	// Replicate logic from 3.x's SegmentInfo.files():
	ISet<string> files = new JCG.HashSet<string>();
	if (isCompoundFile)
	{
	files.Add(IndexFileNames.SegmentFileName(name, "", IndexFileNames.COMPOUND_FILE_EXTENSION));
	}
	else
	{
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xFieldInfosReader.FIELD_INFOS_EXTENSION));
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xPostingsFormat.FREQ_EXTENSION));
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xPostingsFormat.PROX_EXTENSION));
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xPostingsFormat.TERMS_EXTENSION));
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xPostingsFormat.TERMS_INDEX_EXTENSION));
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xNormsProducer.NORMS_EXTENSION));
	}

	if (docStoreOffset != -1)
	{
	if (docStoreIsCompoundFile)
	{
	files.Add(IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xCodec.COMPOUND_FILE_STORE_EXTENSION));
	}
	else
	{
	files.Add(IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xStoredFieldsReader.FIELDS_INDEX_EXTENSION));
	files.Add(IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xStoredFieldsReader.FIELDS_EXTENSION));
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xTermVectorsReader.VECTORS_INDEX_EXTENSION));
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xTermVectorsReader.VECTORS_FIELDS_EXTENSION));
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(docStoreSegment, "", Lucene3xTermVectorsReader.VECTORS_DOCUMENTS_EXTENSION));
	}
	}
	else if (!isCompoundFile)
	{
	files.Add(IndexFileNames.SegmentFileName(name, "", Lucene3xStoredFieldsReader.FIELDS_INDEX_EXTENSION));
	files.Add(IndexFileNames.SegmentFileName(name, "", Lucene3xStoredFieldsReader.FIELDS_EXTENSION));
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xTermVectorsReader.VECTORS_INDEX_EXTENSION));
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xTermVectorsReader.VECTORS_FIELDS_EXTENSION));
	AddIfExists(dir, files, IndexFileNames.SegmentFileName(name, "", Lucene3xTermVectorsReader.VECTORS_DOCUMENTS_EXTENSION));
	}

	// parse the normgen stuff and shove it into attributes
	if (normGen != null)
	{
	attributes[Lucene3xSegmentInfoFormat.NORMGEN_KEY] = Convert.ToString(numNormGen, CultureInfo.InvariantCulture);
	foreach (KeyValuePair<int, long> ent in normGen)
	{
	long gen = ent.Value;
	if (gen >= SegmentInfo.YES)
	{
	// Definitely a separate norm file, with generation:
	files.Add(IndexFileNames.FileNameFromGeneration(name, "s" + ent.Key, gen));
	attributes[Lucene3xSegmentInfoFormat.NORMGEN_PREFIX + ent.Key] = Convert.ToString(gen, CultureInfo.InvariantCulture);
	}
	else if (gen == SegmentInfo.NO)
	{
	// No separate norm
	}
	else
	{
	// We should have already hit indexformat too old exception
	Debug.Assert(false);
	}
	}
	}

	SegmentInfo info = new SegmentInfo(dir, version, name, docCount, isCompoundFile, null, diagnostics, attributes.AsReadOnly());
	info.SetFiles(files);

	SegmentCommitInfo infoPerCommit = new SegmentCommitInfo(info, delCount, delGen, -1);
	return infoPerCommit;
	}

	private SegmentInfo ReadUpgradedSegmentInfo(string name, Directory dir, IndexInput input)
	{
	CodecUtil.CheckHeader(input, Lucene3xSegmentInfoFormat.UPGRADED_SI_CODEC_NAME, Lucene3xSegmentInfoFormat.UPGRADED_SI_VERSION_START, Lucene3xSegmentInfoFormat.UPGRADED_SI_VERSION_CURRENT);
	string version = input.ReadString();

	int docCount = input.ReadInt32();

	IDictionary<string, string> attributes = input.ReadStringStringMap();

	bool isCompoundFile = input.ReadByte() == SegmentInfo.YES;

	IDictionary<string, string> diagnostics = input.ReadStringStringMap();

	ISet<string> files = input.ReadStringSet();

	SegmentInfo info = new SegmentInfo(dir, version, name, docCount, isCompoundFile, null, diagnostics, attributes.AsReadOnly());
	info.SetFiles(files);
	return info;
	}
	}
	}