org.apache.lucene.index.sorter

Class SortingMergePolicy

java.lang.Object

org.apache.lucene.index.MergePolicy

org.apache.lucene.index.sorter.SortingMergePolicy

All Implemented Interfaces:

Closeable, Cloneable

public final class SortingMergePolicy
extends MergePolicy

A MergePolicy that reorders documents according to a Sorter before merging them. As a consequence, all segments resulting from a merge will be sorted while segments resulting from a flush will be in the order in which documents have been added.

NOTE: Never use this MergePolicy if you rely on IndexWriter.addDocuments(Iterable, org.apache.lucene.analysis.Analyzer) to have sequentially-assigned doc IDs, this policy will scatter doc IDs.

NOTE: This MergePolicy should only be used with idempotent Sorters so that the order of segments is predictable. For example, using SortingMergePolicy with Sorter.REVERSE_DOCS (which is not idempotent) will make the order of documents in a segment depend on the number of times the segment has been merged.

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

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.index.MergePolicy

MergePolicy.DocMap, MergePolicy.MergeAbortedException, MergePolicy.MergeException, MergePolicy.MergeSpecification, MergePolicy.MergeTrigger, MergePolicy.OneMerge

Field Summary

Fields

Modifier and Type	Field and Description
static String	SORTER_ID_PROP Put in the diagnostics to denote that this segment is sorted.

Fields inherited from class org.apache.lucene.index.MergePolicy

writer

Constructor Summary

Constructors

Constructor and Description
SortingMergePolicy(MergePolicy in, Sorter sorter) Create a new MergePolicy that sorts documents with sorter.

Method Summary

Methods

Modifier and Type	Method and Description
MergePolicy	clone()
void	close()
MergePolicy.MergeSpecification	findForcedDeletesMerges(SegmentInfos segmentInfos)
MergePolicy.MergeSpecification	findForcedMerges(SegmentInfos segmentInfos, int maxSegmentCount, Map<SegmentInfoPerCommit,Boolean> segmentsToMerge)
MergePolicy.MergeSpecification	findMerges(MergePolicy.MergeTrigger mergeTrigger, SegmentInfos segmentInfos)
static boolean	isSorted(AtomicReader reader, Sorter sorter) Returns true if the given reader is sorted by the given sorter.
void	setIndexWriter(IndexWriter writer)
String	toString()
boolean	useCompoundFile(SegmentInfos segments, SegmentInfoPerCommit newSegment)

Methods inherited from class java.lang.Object

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

Field Detail

SORTER_ID_PROP

public static final String SORTER_ID_PROP

Put in the diagnostics to denote that this segment is sorted.

See Also:

Constant Field Values

Constructor Detail

SortingMergePolicy

public SortingMergePolicy(MergePolicy in,
                  Sorter sorter)

Create a new MergePolicy that sorts documents with sorter.

Method Detail

isSorted

public static boolean isSorted(AtomicReader reader,
               Sorter sorter)

Returns true if the given reader is sorted by the given sorter.

findMerges

public MergePolicy.MergeSpecification findMerges(MergePolicy.MergeTrigger mergeTrigger,
                                        SegmentInfos segmentInfos)
                                          throws IOException

Specified by:

findMerges in class MergePolicy

Throws:

IOException

findForcedMerges

public MergePolicy.MergeSpecification findForcedMerges(SegmentInfos segmentInfos,
                                              int maxSegmentCount,
                                              Map<SegmentInfoPerCommit,Boolean> segmentsToMerge)
                                                throws IOException

Specified by:

findForcedMerges in class MergePolicy

Throws:

IOException

findForcedDeletesMerges

public MergePolicy.MergeSpecification findForcedDeletesMerges(SegmentInfos segmentInfos)
                                                       throws IOException

Specified by:

findForcedDeletesMerges in class MergePolicy

Throws:

IOException

clone

public MergePolicy clone()

Overrides:

clone in class MergePolicy

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in class MergePolicy

useCompoundFile

public boolean useCompoundFile(SegmentInfos segments,
                      SegmentInfoPerCommit newSegment)
                        throws IOException

Specified by:

useCompoundFile in class MergePolicy

Throws:

IOException

setIndexWriter

public void setIndexWriter(IndexWriter writer)

Overrides:

setIndexWriter in class MergePolicy

toString

public String toString()

Overrides:

toString in class Object