Class NoMergePolicy

A MergePolicy which never returns merges to execute (hence it's name). It is also a singleton and can be accessed through NO_COMPOUND_FILES if you want to indicate the index does not use compound files, or through COMPOUND_FILES otherwise. Use it if you want to prevent an IndexWriter from ever executing merges, without going through the hassle of tweaking a merge policy's settings to achieve that, such as changing its merge factor.

Inheritance
object
MergePolicy
NoMergePolicy
Implements
Inherited Members
Namespace: Lucene.Net.Index
Assembly: Lucene.Net.dll
Syntax
public sealed class NoMergePolicy : MergePolicy, IDisposable

Fields

COMPOUND_FILES

A singleton NoMergePolicy which indicates the index uses compound files.

Declaration
public static readonly MergePolicy COMPOUND_FILES
Field Value
Type Description
MergePolicy

NO_COMPOUND_FILES

A singleton NoMergePolicy which indicates the index does not use compound files.

Declaration
public static readonly MergePolicy NO_COMPOUND_FILES
Field Value
Type Description
MergePolicy

Methods

Dispose(bool)

Release all resources for the policy.

Declaration
protected override void Dispose(bool disposing)
Parameters
Type Name Description
bool disposing
Overrides

FindForcedDeletesMerges(SegmentInfos)

Determine what set of merge operations is necessary in order to expunge all deletes from the index.

Declaration
public override MergePolicy.MergeSpecification FindForcedDeletesMerges(SegmentInfos segmentInfos)
Parameters
Type Name Description
SegmentInfos segmentInfos

the total set of segments in the index
Returns
Type Description
MergePolicy.MergeSpecification
Overrides

FindForcedMerges(SegmentInfos, int, IDictionary<SegmentCommitInfo, bool>)

Determine what set of merge operations is necessary in order to merge to <= the specified segment count. IndexWriter calls this when its ForceMerge(int, bool) method is called. This call is always synchronized on the IndexWriter instance so only one thread at a time will call this method.

Declaration
public override MergePolicy.MergeSpecification FindForcedMerges(SegmentInfos segmentInfos, int maxSegmentCount, IDictionary<SegmentCommitInfo, bool> segmentsToMerge)
Parameters
Type Name Description
SegmentInfos segmentInfos

The total set of segments in the index
int maxSegmentCount

Requested maximum number of segments in the index (currently this is always 1)
IDictionary<SegmentCommitInfo, bool> 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.
Returns
Type Description
MergePolicy.MergeSpecification
Overrides

FindMerges(MergeTrigger, SegmentInfos)

Determine what set of merge operations are now necessary on the index. 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.

Declaration
public override MergePolicy.MergeSpecification FindMerges(MergeTrigger mergeTrigger, SegmentInfos segmentInfos)
Parameters
Type Name Description
MergeTrigger mergeTrigger

the event that triggered the merge
SegmentInfos segmentInfos

the total set of segments in the index
Returns
Type Description
MergePolicy.MergeSpecification
Overrides

SetIndexWriter(IndexWriter)

Sets the 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, AlreadySetException is thrown.

Declaration
public override void SetIndexWriter(IndexWriter writer)
Parameters
Type Name Description
IndexWriter writer
Overrides
See Also

Size(SegmentCommitInfo)

Return the byte size of the provided SegmentCommitInfo, pro-rated by percentage of non-deleted documents is set.

Declaration
protected override long Size(SegmentCommitInfo info)
Parameters
Type Name Description
SegmentCommitInfo info
Returns
Type Description
long
Overrides

ToString()

Returns a string that represents the current object.

Declaration
public override string ToString()
Returns
Type Description
string

A string that represents the current object.
Overrides

UseCompoundFile(SegmentInfos, SegmentCommitInfo)

Returns true if a new segment (regardless of its origin) should use the compound file format. The default implementation returns true iff the size of the given mergedInfo is less or equal to MaxCFSSegmentSizeMB and the size is less or equal to the TotalIndexSize * NoCFSRatio otherwise 

false
.
Declaration
public override bool UseCompoundFile(SegmentInfos segments, SegmentCommitInfo newSegment)
Parameters
Type Name Description
SegmentInfos segments
SegmentCommitInfo newSegment
Returns
Type Description
bool
Overrides

Implements