Class PersistentSnapshotDeletionPolicy

A SnapshotDeletionPolicy which adds a persistence layer so that snapshots can be maintained across the life of an application. The snapshots are persisted in a Directory and are committed as soon as Snapshot() or Release(IndexCommit) is called.

NOTE: Sharing PersistentSnapshotDeletionPolicys that write to the same directory across IndexWriters will corrupt snapshots. You should make sure every IndexWriter has its own PersistentSnapshotDeletionPolicy and that they all write to a different Directory. It is OK to use the same Directory that holds the index.

This class adds a Release(Int64) method to release commits from a previous snapshot's Generation.

Note

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

Inheritance

System.Object

IndexDeletionPolicy

SnapshotDeletionPolicy

PersistentSnapshotDeletionPolicy

Inherited Members

SnapshotDeletionPolicy.m_refCounts

SnapshotDeletionPolicy.m_indexCommits

SnapshotDeletionPolicy.m_lastCommit

SnapshotDeletionPolicy.OnCommit<T>(IList<T>)

SnapshotDeletionPolicy.OnInit<T>(IList<T>)

SnapshotDeletionPolicy.ReleaseGen(Int64)

SnapshotDeletionPolicy.IncRef(IndexCommit)

SnapshotDeletionPolicy.GetSnapshots()

SnapshotDeletionPolicy.SnapshotCount

SnapshotDeletionPolicy.GetIndexCommit(Int64)

SnapshotDeletionPolicy.Clone()

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.Index

Assembly: Lucene.Net.dll

Syntax

public class PersistentSnapshotDeletionPolicy : SnapshotDeletionPolicy

Constructors

PersistentSnapshotDeletionPolicy(IndexDeletionPolicy, Directory)

PersistentSnapshotDeletionPolicy wraps another IndexDeletionPolicy to enable flexible snapshotting, passing CREATE_OR_APPEND by default.

Declaration

public PersistentSnapshotDeletionPolicy(IndexDeletionPolicy primary, Directory dir)

Parameters

Type	Name	Description
IndexDeletionPolicy	primary	the IndexDeletionPolicy that is used on non-snapshotted commits. Snapshotted commits, by definition, are not deleted until explicitly released via Release(IndexCommit).
Directory	dir	the Directory which will be used to persist the snapshots information.

PersistentSnapshotDeletionPolicy(IndexDeletionPolicy, Directory, OpenMode)

PersistentSnapshotDeletionPolicy wraps another IndexDeletionPolicy to enable flexible snapshotting.

Declaration

public PersistentSnapshotDeletionPolicy(IndexDeletionPolicy primary, Directory dir, OpenMode mode)

Parameters

Type	Name	Description
IndexDeletionPolicy	primary	the IndexDeletionPolicy that is used on non-snapshotted commits. Snapshotted commits, by definition, are not deleted until explicitly released via Release(IndexCommit).
Directory	dir	the Directory which will be used to persist the snapshots information.
OpenMode	mode	specifies whether a new index should be created, deleting all existing snapshots information (immediately), or open an existing index, initializing the class with the snapshots information.

Fields

SNAPSHOTS_PREFIX

Prefix used for the save file.

Declaration

public const string SNAPSHOTS_PREFIX = "snapshots_"

Field Value

Type	Description
System.String

Properties

LastSaveFile

Returns the file name the snapshots are currently saved to, or null if no snapshots have been saved.

Declaration

public virtual string LastSaveFile { get; }

Property Value

Type	Description
System.String

Methods

Release(IndexCommit)

Deletes a snapshotted commit. Once this method returns, the snapshot information is persisted in the directory.

Declaration

public override void Release(IndexCommit commit)

Parameters

Type	Name	Description
IndexCommit	commit

Overrides

SnapshotDeletionPolicy.Release(IndexCommit)

See Also

Release(IndexCommit)

Release(Int64)

Deletes a snapshotted commit by generation. Once this method returns, the snapshot information is persisted in the directory.

Declaration

public virtual void Release(long gen)

Parameters

Type	Name	Description
System.Int64	gen

See Also

Generation

Release(IndexCommit)

Snapshot()

Snapshots the last commit. Once this method returns, the snapshot information is persisted in the directory.

Declaration

public override IndexCommit Snapshot()

Returns

Type	Description
IndexCommit

Overrides

SnapshotDeletionPolicy.Snapshot()

See Also

Snapshot()