org.apache.lucene.index

Class MergePolicy.OneMerge

java.lang.Object

org.apache.lucene.index.MergePolicy.OneMerge

Enclosing class:

MergePolicy

public static class MergePolicy.OneMerge
extends Object

OneMerge provides the information necessary to perform an individual primitive merge operation, resulting in a single new segment. The merge spec includes the subset of segments to be merged as well as whether the new segment should use the compound file format.

Field Summary

Fields

Modifier and Type	Field and Description
long	estimatedMergeBytes Estimated size in bytes of the merged segment.
List<SegmentCommitInfo>	segments Segments to be merged.
int	totalDocCount Number of documents in the merged segment.

Constructor Summary

Constructors

Constructor and Description
MergePolicy.OneMerge(List<SegmentCommitInfo> segments) Sole constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	checkAborted(Directory dir) Called periodically by IndexWriter while merging to see if the merge is aborted.
MergePolicy.DocMap	getDocMap(MergeState mergeState) Expert: If getMergeReaders() reorders document IDs, this method must be overridden to return a mapping from the natural doc ID (the doc ID that would result from a natural merge) to the actual doc ID.
MergeInfo	getMergeInfo() Return MergeInfo describing this merge.
List<AtomicReader>	getMergeReaders() Expert: Get the list of readers to merge.
boolean	getPause() Returns true if this merge is paused.
String	segString(Directory dir) Returns a readable description of the current merge state.
void	setInfo(SegmentCommitInfo info) Expert: Sets the SegmentCommitInfo of this MergePolicy.OneMerge.
void	setPause(boolean paused) Set or clear whether this merge is paused paused (for example ConcurrentMergeScheduler will pause merges if too many are running).
long	totalBytesSize() Returns the total size in bytes of this merge.
int	totalNumDocs() Returns the total number of documents that are included with this merge.

Methods inherited from class java.lang.Object

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

Field Detail

estimatedMergeBytes

public volatile long estimatedMergeBytes

Estimated size in bytes of the merged segment.

segments

public final List<SegmentCommitInfo> segments

Segments to be merged.

totalDocCount

public final int totalDocCount

Number of documents in the merged segment.

Constructor Detail

MergePolicy.OneMerge

public MergePolicy.OneMerge(List<SegmentCommitInfo> segments)

Sole constructor.

Parameters:

segments - List of SegmentCommitInfos to be merged.

Method Detail

getMergeReaders

public List<AtomicReader> getMergeReaders()
                                   throws IOException

Expert: Get the list of readers to merge. Note that this list does not necessarily match the list of segments to merge and should only be used to feed SegmentMerger to initialize a merge. When a MergePolicy.OneMerge reorders doc IDs, it must override getDocMap(org.apache.lucene.index.MergeState) too so that deletes that happened during the merge can be applied to the newly merged segment.

Throws:

IOException

setInfo

public void setInfo(SegmentCommitInfo info)

Expert: Sets the SegmentCommitInfo of this MergePolicy.OneMerge. Allows sub-classes to e.g. set diagnostics properties.

getDocMap

public MergePolicy.DocMap getDocMap(MergeState mergeState)

Expert: If getMergeReaders() reorders document IDs, this method must be overridden to return a mapping from the natural doc ID (the doc ID that would result from a natural merge) to the actual doc ID. This mapping is used to apply deletions that happened during the merge to the new segment.

checkAborted

public void checkAborted(Directory dir)
                  throws MergePolicy.MergeAbortedException

Called periodically by IndexWriter while merging to see if the merge is aborted.

Throws:

MergePolicy.MergeAbortedException

setPause

public void setPause(boolean paused)

Set or clear whether this merge is paused paused (for example ConcurrentMergeScheduler will pause merges if too many are running).

getPause

public boolean getPause()

Returns true if this merge is paused.

See Also:

setPause(boolean)

segString

public String segString(Directory dir)

Returns a readable description of the current merge state.

totalBytesSize

public long totalBytesSize()
                    throws IOException

Returns the total size in bytes of this merge. Note that this does not indicate the size of the merged segment, but the input total size. This is only set once the merge is initialized by IndexWriter.

Throws:

IOException

totalNumDocs

public int totalNumDocs()
                 throws IOException

Returns the total number of documents that are included with this merge. Note that this does not indicate the number of documents after the merge.

Throws:

IOException

getMergeInfo

public MergeInfo getMergeInfo()

Return MergeInfo describing this merge.