Package org.apache.lucene.replicator

Class LocalReplicator

java.lang.Object

org.apache.lucene.replicator.LocalReplicator

All Implemented Interfaces:

Closeable, AutoCloseable, Replicator

public class LocalReplicator
extends Object
implements Replicator

A Replicator implementation for use by the side that publishes Revisions, as well for clients to check for updates. When a client needs to be updated, it is returned a SessionToken through which it can obtain the files of that revision. As long as a revision is being replicated, this replicator guarantees that it will not be released.

Replication sessions expire by default after DEFAULT_SESSION_EXPIRATION_THRESHOLD, and the threshold can be configured through setExpirationThreshold(long).

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

Field Summary

Fields

Modifier and Type	Field	Description
static long	DEFAULT_SESSION_EXPIRATION_THRESHOLD	Threshold for expiring inactive sessions.

Constructor Summary

Constructors

Constructor	Description
LocalReplicator()

Method Summary

Modifier and Type	Method	Description
SessionToken	checkForUpdate(String currentVersion)	Check whether the given version is up-to-date and returns a SessionToken which can be used for fetching the revision files, otherwise returns null.
void	close()
protected void	ensureOpen()	Ensure that replicator is still open, or throw AlreadyClosedException otherwise.
long	getExpirationThreshold()	Returns the expiration threshold.
InputStream	obtainFile(String sessionID, String source, String fileName)	Returns an InputStream for the requested file and source in the context of the given session.
void	publish(Revision revision)	Publish a new Revision for consumption by clients.
void	release(String sessionID)	Notify that the specified SessionToken is no longer needed by the caller.
void	setExpirationThreshold(long expirationThreshold)	Modify session expiration time - if a replication session is inactive that long it is automatically expired, and further attempts to operate within this session will throw a SessionExpiredException.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_SESSION_EXPIRATION_THRESHOLD

public static final long DEFAULT_SESSION_EXPIRATION_THRESHOLD

Threshold for expiring inactive sessions. Defaults to 30 minutes.

See Also:

Constant Field Values

Constructor Detail

LocalReplicator

public LocalReplicator()

Method Detail

ensureOpen

protected final void ensureOpen()

Ensure that replicator is still open, or throw AlreadyClosedException otherwise.

checkForUpdate

public SessionToken checkForUpdate(String currentVersion)

Description copied from interface: Replicator

Check whether the given version is up-to-date and returns a SessionToken which can be used for fetching the revision files, otherwise returns null.

NOTE: when the returned session token is no longer needed, you should call Replicator.release(String) so that the session resources can be reclaimed, including the revision files.

Specified by:

checkForUpdate in interface Replicator

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException

getExpirationThreshold

public long getExpirationThreshold()

Returns the expiration threshold.

See Also:

setExpirationThreshold(long)

obtainFile

public InputStream obtainFile(String sessionID,
                              String source,
                              String fileName)
                       throws IOException

Description copied from interface: Replicator

Returns an InputStream for the requested file and source in the context of the given session.

NOTE: it is the caller's responsibility to close the returned stream.

Specified by:

obtainFile in interface Replicator

Throws:

SessionExpiredException - if the specified session has already expired

IOException

publish

public void publish(Revision revision)
             throws IOException

Description copied from interface: Replicator

Publish a new Revision for consumption by clients. It is the caller's responsibility to verify that the revision files exist and can be read by clients. When the revision is no longer needed, it will be released by the replicator.

Specified by:

publish in interface Replicator

Throws:

IOException

release

public void release(String sessionID)
             throws IOException

Description copied from interface: Replicator

Notify that the specified SessionToken is no longer needed by the caller.

Specified by:

release in interface Replicator

Throws:

IOException

setExpirationThreshold

public void setExpirationThreshold(long expirationThreshold)
                            throws IOException

Modify session expiration time - if a replication session is inactive that long it is automatically expired, and further attempts to operate within this session will throw a SessionExpiredException.

Throws:

IOException