org.apache.lucene.index
Class FSTransLog

java.lang.Object
  org.apache.lucene.index.FSTransLog

All Implemented Interfaces:

TransLog, CompassConfigurable

public class FSTransLog
extends Object
implements TransLog

A transaction log that saves most of the transactional data log into disk.

Can be provided with a transaction log path (using LuceneEnvironment.Transaction.TransLog.PATH setting), where different directories will be created in (in the form of PATH/compass/translog/[tran id]). All the trans data is stored into a single file called transdata.

Two parameters can be set on this transaction log as well, the first is read buffer size, which controls the size of the buffer for read operations. This can affect the memory consumption of this transaction log, and defaults to 64 (bytes). The write buffer is the memory buffer used to write data into the file system, and defaults to 2048 (bytes). It is pooled so does not affect memory consumption that much.

Author:

kimchy

Nested Class Summary

(package private) class

FSTransLog.TransDirectory Transactional log directory implementation, writes all the data into memory until FSTransLog.TransDirectory.flush() is called (it is called in the onDocumentAdded() callback).

Constructor Summary

FSTransLog()

Method Summary

void	close() Closes the transaction log.
void	configure(CompassSettings settings) Configure using the given settings.
Directory	getDirectory() Returns the Lucene directory the transaction log will be written to
void	onDocumentAdded() A callback notifiying the trasaction log that a document was added (can be used for flushing for example).
boolean	shouldUpdateTransSegments() Returns true if the transaction segments should be written for each change made to it.

Methods inherited from class java.lang.Object

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

Constructor Detail

FSTransLog

public FSTransLog()

Method Detail

configure

public void configure(CompassSettings settings)
               throws CompassException

Description copied from interface: CompassConfigurable

Configure using the given settings.

Specified by:

configure in interface CompassConfigurable

Parameters:

settings - The settings for the configured object

Throws:

CompassException

getDirectory

public Directory getDirectory()

Description copied from interface: TransLog

Returns the Lucene directory the transaction log will be written to

Specified by:

getDirectory in interface TransLog

shouldUpdateTransSegments

public boolean shouldUpdateTransSegments()

Description copied from interface: TransLog

Returns true if the transaction segments should be written for each change made to it.

Specified by:

shouldUpdateTransSegments in interface TransLog

close

public void close()
           throws IOException

Description copied from interface: TransLog

Closes the transaction log.

Specified by:

close in interface TransLog

Throws:

IOException

onDocumentAdded

public void onDocumentAdded()
                     throws IOException

Description copied from interface: TransLog

A callback notifiying the trasaction log that a document was added (can be used for flushing for example).

Specified by:

onDocumentAdded in interface TransLog

Throws:

IOException