public final class SortingMergePolicy extends MergePolicy
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
Sorter
s 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.
MergePolicy.DocMap, MergePolicy.MergeAbortedException, MergePolicy.MergeException, MergePolicy.MergeSpecification, MergePolicy.MergeTrigger, MergePolicy.OneMerge
Modifier and Type | Field and Description |
---|---|
static String |
SORTER_ID_PROP
Put in the
diagnostics to denote that
this segment is sorted. |
Constructor and Description |
---|
SortingMergePolicy(MergePolicy in,
Sorter sorter)
Create a new
MergePolicy that sorts documents with sorter . |
Modifier and Type | Method and Description |
---|---|
MergePolicy |
clone() |
void |
close()
Release all resources for the policy.
|
MergePolicy.MergeSpecification |
findForcedDeletesMerges(SegmentInfos segmentInfos)
Determine what set of merge operations is necessary in order to expunge all
deletes from the index.
|
MergePolicy.MergeSpecification |
findForcedMerges(SegmentInfos segmentInfos,
int maxSegmentCount,
Map<SegmentCommitInfo,Boolean> segmentsToMerge)
Determine what set of merge operations is necessary in
order to merge to <= the specified segment count.
|
MergePolicy.MergeSpecification |
findMerges(MergePolicy.MergeTrigger mergeTrigger,
SegmentInfos segmentInfos)
Determine what set of merge operations are now necessary on the index.
|
static boolean |
isSorted(AtomicReader reader,
Sorter sorter)
Returns true if the given reader is sorted by the given sorter.
|
void |
setIndexWriter(IndexWriter writer)
Sets the
IndexWriter to use by this merge policy. |
String |
toString() |
boolean |
useCompoundFile(SegmentInfos segments,
SegmentCommitInfo newSegment)
Returns true if a new segment (regardless of its origin) should use the
compound file format.
|
getMaxCFSSegmentSizeMB, getNoCFSRatio, setMaxCFSSegmentSizeMB, setNoCFSRatio
public static final String SORTER_ID_PROP
diagnostics
to denote that
this segment is sorted.public SortingMergePolicy(MergePolicy in, Sorter sorter)
MergePolicy
that sorts documents with sorter
.public static boolean isSorted(AtomicReader reader, Sorter sorter)
public MergePolicy.MergeSpecification findMerges(MergePolicy.MergeTrigger mergeTrigger, SegmentInfos segmentInfos) throws IOException
MergePolicy
IndexWriter
calls this whenever there is a change to the segments.
This call is always synchronized on the IndexWriter
instance so
only one thread at a time will call this method.findMerges
in class MergePolicy
mergeTrigger
- the event that triggered the mergesegmentInfos
- the total set of segments in the indexIOException
public MergePolicy.MergeSpecification findForcedMerges(SegmentInfos segmentInfos, int maxSegmentCount, Map<SegmentCommitInfo,Boolean> segmentsToMerge) throws IOException
MergePolicy
IndexWriter
calls this when its
IndexWriter.forceMerge(int)
method is called. This call is always
synchronized on the IndexWriter
instance so only one thread at a
time will call this method.findForcedMerges
in class MergePolicy
segmentInfos
- the total set of segments in the indexmaxSegmentCount
- requested maximum number of segments in the index (currently this
is always 1)segmentsToMerge
- contains the specific SegmentInfo instances that must be merged
away. This may be a subset of all
SegmentInfos. If the value is True for a
given SegmentInfo, that means this segment was
an original segment present in the
to-be-merged index; else, it was a segment
produced by a cascaded merge.IOException
public MergePolicy.MergeSpecification findForcedDeletesMerges(SegmentInfos segmentInfos) throws IOException
MergePolicy
findForcedDeletesMerges
in class MergePolicy
segmentInfos
- the total set of segments in the indexIOException
public MergePolicy clone()
clone
in class MergePolicy
public void close()
MergePolicy
close
in interface Closeable
close
in interface AutoCloseable
close
in class MergePolicy
public boolean useCompoundFile(SegmentInfos segments, SegmentCommitInfo newSegment) throws IOException
MergePolicy
true
iff the size of the given mergedInfo is less or equal to
MergePolicy.getMaxCFSSegmentSizeMB()
and the size is less or equal to the
TotalIndexSize * MergePolicy.getNoCFSRatio()
otherwise false
.useCompoundFile
in class MergePolicy
IOException
public void setIndexWriter(IndexWriter writer)
MergePolicy
IndexWriter
to use by this merge policy. This method is
allowed to be called only once, and is usually set by IndexWriter. If it is
called more than once, SetOnce.AlreadySetException
is thrown.setIndexWriter
in class MergePolicy
SetOnce
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