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.

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

Field Summary

Fields

Modifier and Type	Field and Description
long	estimatedMergeBytes Estimated size in bytes of the merged segment.
MergeRateLimiter	rateLimiter A private RateLimiter for this merge, used to rate limit writes and abort.
List<SegmentCommitInfo>	segments Segments to be merged.
int	totalMaxDoc Total number of documents in segments to be merged, not accounting for deletions.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
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.
SegmentCommitInfo	getMergeInfo() Returns the SegmentCommitInfo for the merged segment, or null if it hasn't been set yet.
List<CodecReader>	getMergeReaders() Expert: Get the list of readers to merge.
MergeInfo	getStoreMergeInfo() Return MergeInfo describing this merge.
void	mergeFinished() Called by IndexWriter after the merge is done and all readers have been closed.
String	segString() Returns a readable description of the current merge state.
void	setMergeInfo(SegmentCommitInfo info) Expert: Sets the SegmentCommitInfo of the merged segment.
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.

rateLimiter

public final MergeRateLimiter rateLimiter

A private RateLimiter for this merge, used to rate limit writes and abort.

totalMaxDoc

public final int totalMaxDoc

Total number of documents in segments to be merged, not accounting for deletions.

Constructor Detail

OneMerge

public OneMerge(List<SegmentCommitInfo> segments)

Sole constructor.

Parameters:

segments - List of SegmentCommitInfos to be merged.

Method Detail

mergeFinished

public void mergeFinished()
                   throws IOException

Called by IndexWriter after the merge is done and all readers have been closed.

Throws:

IOException

getMergeReaders

public List<CodecReader> 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

setMergeInfo

public void setMergeInfo(SegmentCommitInfo info)

Expert: Sets the SegmentCommitInfo of the merged segment. Allows sub-classes to e.g. set diagnostics properties.

getMergeInfo

public SegmentCommitInfo getMergeInfo()

Returns the SegmentCommitInfo for the merged segment, or null if it hasn't been set yet.

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.

segString

public String segString()

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

getStoreMergeInfo

public MergeInfo getStoreMergeInfo()

Return MergeInfo describing this merge.