Package 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.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	MergeScheduler.MergeSource	Provides access to new merges and executes the actual merge

Field Summary

Fields

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

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	MergeScheduler()	Sole constructor.

Method Summary

Modifier and Type	Method	Description
abstract void	close()	Close this MergeScheduler.
(package private) void	initialize(InfoStream infoStream, Directory directory)	IndexWriter calls this on init.
abstract void	merge(MergeScheduler.MergeSource mergeSource, MergeTrigger trigger)	Run the merges provided by MergeScheduler.MergeSource.getNextMerge().
protected void	message(java.lang.String message)	Outputs the given message - this method assumes verbose() was called and returned true.
protected boolean	verbose()	Returns true if infoStream messages are enabled.
Directory	wrapForMerge(MergePolicy.OneMerge merge, Directory in)	Wraps the incoming Directory so that we can merge-throttle it using RateLimitedIndexOutput.

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(MergeScheduler.MergeSource mergeSource,
                           MergeTrigger trigger)
                    throws java.io.IOException

Run the merges provided by MergeScheduler.MergeSource.getNextMerge().

Parameters:

mergeSource - the IndexWriter to obtain the merges from.

trigger - the MergeTrigger that caused this merge to happen

Throws:

java.io.IOException

wrapForMerge

public Directory wrapForMerge(MergePolicy.OneMerge merge,
                              Directory in)

Wraps the incoming Directory so that we can merge-throttle it using RateLimitedIndexOutput.

close

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

Close this MergeScheduler.

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Throws:

java.io.IOException

initialize

void initialize(InfoStream infoStream,
                Directory directory)
         throws java.io.IOException

IndexWriter calls this on init.

Throws:

java.io.IOException

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.