org.apache.lucene.index

Class MergeScheduler

java.lang.Object

org.apache.lucene.index.MergeScheduler

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

Direct Known Subclasses:

ConcurrentMergeScheduler, NoMergeScheduler, SerialMergeScheduler

public abstract class MergeScheduler
extends java.lang.Object
implements java.io.Closeable

Expert: IndexWriter uses an instance implementing this interface to execute the merges selected by a MergePolicy. The default MergeScheduler is ConcurrentMergeScheduler.

Implementers of sub-classes should make sure that Object.clone() returns an independent instance able to work with any IndexWriter instance.

Field Summary

Fields

Modifier and Type	Field and Description
protected InfoStream	infoStream For messages about merge scheduling

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MergeScheduler() Sole constructor.

Method Summary

Modifier and Type	Method and Description
abstract void	close() Close this MergeScheduler.
abstract void	merge(IndexWriter writer, MergeTrigger trigger, boolean newMergesFound) Run the merges provided by IndexWriter.getNextMerge().
protected void	message(java.lang.String message) Outputs the given message - this method assumes verbose() was called and returned true.
(package private) void	setInfoStream(InfoStream infoStream) IndexWriter calls this on init.
protected boolean	verbose() Returns true if infoStream messages are enabled.

Methods inherited from class java.lang.Object

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

Field Detail

infoStream

protected InfoStream infoStream

For messages about merge scheduling

Constructor Detail

MergeScheduler

protected MergeScheduler()

Sole constructor. (For invocation by subclass constructors, typically implicit.)

Method Detail

merge

public abstract void merge(IndexWriter writer,
                           MergeTrigger trigger,
                           boolean newMergesFound)
                    throws java.io.IOException

Run the merges provided by IndexWriter.getNextMerge().

Parameters:

writer - the IndexWriter to obtain the merges from.

trigger - the MergeTrigger that caused this merge to happen

newMergesFound - true iff any new merges were found by the caller otherwise false

Throws:

java.io.IOException

close

public abstract void close()
                    throws java.io.IOException

Close this MergeScheduler.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.io.IOException

setInfoStream

final void setInfoStream(InfoStream infoStream)

IndexWriter calls this on init.

verbose

protected boolean verbose()

Returns true if infoStream messages are enabled. This method is usually used in conjunction with message(String):

 if (verbose()) {
   message("your message");
 }
 

message

protected void message(java.lang.String message)

Outputs the given message - this method assumes verbose() was called and returned true.