Class IndexReplicationHandler

A IReplicationHandler for replication of an index. Implements RevisionReady(String, IDictionary<String, IList<RevisionFile>>, IDictionary<String, IList<String>>, IDictionary<String, Directory>) by copying the files pointed by the client resolver to the index Lucene.Net.Store.Directory and then touches the index with Lucene.Net.Index.IndexWriter to make sure any unused files are deleted.

Inheritance

System.Object

IndexReplicationHandler

Implements

IReplicationHandler

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: Lucene.Net.Replicator

Assembly: Lucene.Net.Replicator.dll

Syntax

public class IndexReplicationHandler : IReplicationHandler

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided System.Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

Constructors

IndexReplicationHandler(Directory, Action)

Constructor with the given index directory and callback to notify when the indexes were updated.

Declaration

public IndexReplicationHandler(Directory indexDirectory, Action callback)

Parameters

Type	Name	Description
Lucene.Net.Store.Directory	indexDirectory
System.Action	callback

Fields

INFO_STREAM_COMPONENT

The component used to log messages to the Lucene.Net.Util.InfoStream.Default Lucene.Net.Util.InfoStream.

Declaration

public const string INFO_STREAM_COMPONENT = "IndexReplicationHandler"

Field Value

Type	Description
System.String

Properties

CurrentRevisionFiles

Declaration

public virtual IDictionary<string, IList<RevisionFile>> CurrentRevisionFiles { get; }

Property Value

Type	Description
System.Collections.Generic.IDictionary<System.String, System.Collections.Generic.IList<RevisionFile>>

CurrentVersion

Declaration

public virtual string CurrentVersion { get; }

Property Value

Type	Description
System.String

InfoStream

Gets or sets the Lucene.Net.Util.InfoStream to use for logging messages.

Declaration

public virtual InfoStream InfoStream { get; set; }

Property Value

Type	Description
Lucene.Net.Util.InfoStream

Methods

CleanupFilesOnFailure(Directory, IList<String>)

Cleanup the index directory by deleting all given files. Called when file copy or sync failed.

Declaration

public static void CleanupFilesOnFailure(Directory directory, IList<string> files)

Parameters

Type	Name	Description
Lucene.Net.Store.Directory	directory
System.Collections.Generic.IList<System.String>	files

CleanupOldIndexFiles(Directory, String)

Cleans up the index directory from old index files. This method uses the last commit found by GetLastCommit(Directory). If it matches the expected segmentsFile, then all files not referenced by this commit point are deleted.

Declaration

public static void CleanupOldIndexFiles(Directory directory, string segmentsFile)

Parameters

Type	Name	Description
Lucene.Net.Store.Directory	directory
System.String	segmentsFile

Remarks

NOTE: This method does a best effort attempt to clean the index directory. It suppresses any exceptions that occur, as this can be retried the next time.

CopyFiles(Directory, Directory, IList<String>)

Copies the provided list of files from the source Lucene.Net.Store.Directory to the target Lucene.Net.Store.Directory, if they are not the same.

Declaration

public static void CopyFiles(Directory source, Directory target, IList<string> files)

Parameters

Type	Name	Description
Lucene.Net.Store.Directory	source
Lucene.Net.Store.Directory	target
System.Collections.Generic.IList<System.String>	files

Exceptions

Type	Condition
System.IO.IOException

GetLastCommit(Directory)

Returns the last Lucene.Net.Index.IndexCommit found in the Lucene.Net.Store.Directory, or null if there are no commits.

Declaration

public static IndexCommit GetLastCommit(Directory directory)

Parameters

Type	Name	Description
Lucene.Net.Store.Directory	directory

Returns

Type	Description
Lucene.Net.Index.IndexCommit

Exceptions

Type	Condition
System.IO.IOException

GetSegmentsFile(IList<String>, Boolean)

Verifies that the last file is segments_N and fails otherwise. It also removes and returns the file from the list, because it needs to be handled last, after all files. This is important in order to guarantee that if a reader sees the new segments_N, all other segment files are already on stable storage.

The reason why the code fails instead of putting segments_N file last is that this indicates an error in the IRevision implementation.

Declaration

public static string GetSegmentsFile(IList<string> files, bool allowEmpty)

Parameters

Type	Name	Description
System.Collections.Generic.IList<System.String>	files
System.Boolean	allowEmpty

Returns

Type	Description
System.String

RevisionReady(String, IDictionary<String, IList<RevisionFile>>, IDictionary<String, IList<String>>, IDictionary<String, Directory>)

Declaration

public virtual void RevisionReady(string version, IDictionary<string, IList<RevisionFile>> revisionFiles, IDictionary<string, IList<string>> copiedFiles, IDictionary<string, Directory> sourceDirectory)

Parameters

Type	Name	Description
System.String	version
System.Collections.Generic.IDictionary<System.String, System.Collections.Generic.IList<RevisionFile>>	revisionFiles
System.Collections.Generic.IDictionary<System.String, System.Collections.Generic.IList<System.String>>	copiedFiles
System.Collections.Generic.IDictionary<System.String, Lucene.Net.Store.Directory>	sourceDirectory

WriteSegmentsGen(String, Directory)

Writes SEGMENTS_GEN file to the directory, reading the generation from the given segmentsFile. If it is null, this method deletes segments.gen from the directory.

Declaration

public static void WriteSegmentsGen(string segmentsFile, Directory directory)

Parameters

Type	Name	Description
System.String	segmentsFile
Lucene.Net.Store.Directory	directory

Implements

IReplicationHandler