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Public Member Functions | Static Public Member Functions | Data Fields | Static Public Attributes | Protected Member Functions | Protected Attributes
Lucene::LogMergePolicy Class Referenceabstract

This class implements a MergePolicy that tries to merge segments into levels of exponentially increasing size, where each level has fewer segments than the value of the merge factor. Whenever extra segments (beyond the merge factor upper bound) are encountered, all segments within the level are merged. You can get or set the merge factor using getMergeFactor() and setMergeFactor(int) respectively. More...

#include <LogMergePolicy.h>

+ Inheritance diagram for Lucene::LogMergePolicy:

Public Member Functions

 LogMergePolicy (const IndexWriterPtr &writer)
 
virtual ~LogMergePolicy ()
 
virtual String getClassName ()
 
boost::shared_ptr< LogMergePolicyshared_from_this ()
 
double getNoCFSRatio ()
 
void setNoCFSRatio (double noCFSRatio)
 If a merged segment will be more than this percentage of the total size of the index, leave the segment as non-compound file even if compound file is enabled. Set to 1.0 to always use CFS regardless of merge size.
 
int32_t getMergeFactor ()
 Returns the number of segments that are merged at once and also controls the total number of segments allowed to accumulate in the index.
 
void setMergeFactor (int32_t mergeFactor)
 Determines how often segment indices are merged by addDocument(). With smaller values, less RAM is used while indexing, and searches on unoptimized indices are faster, but indexing speed is slower. With larger values, more RAM is used during indexing, and while searches on unoptimized indices are slower, indexing is faster. Thus larger values (> 10) are best for batch index creation, and smaller values (< 10) for indices that are interactively maintained.
 
virtual bool useCompoundFile (const SegmentInfosPtr &segments, const SegmentInfoPtr &newSegment)
 Returns true if a newly flushed (not from merge) segment should use the compound file format.
 
void setUseCompoundFile (bool useCompoundFile)
 Sets whether compound file format should be used for newly flushed and newly merged segments.
 
bool getUseCompoundFile ()
 Returns true if newly flushed and newly merge segments are written in compound file format.
 
virtual bool useCompoundDocStore (const SegmentInfosPtr &segments)
 Returns true if the doc store files should use the compound file format.
 
void setUseCompoundDocStore (bool useCompoundDocStore)
 Sets whether compound file format should be used for newly flushed and newly merged doc store segment files (term vectors and stored fields).
 
bool getUseCompoundDocStore ()
 Returns true if newly flushed and newly merge doc store segment files (term vectors and stored fields) are written in compound file format.
 
void setCalibrateSizeByDeletes (bool calibrateSizeByDeletes)
 Sets whether the segment size should be calibrated by the number of deletes when choosing segments for merge.
 
bool getCalibrateSizeByDeletes ()
 Returns true if the segment size should be calibrated by the number of deletes when choosing segments for merge.
 
virtual void close ()
 Release all resources for the policy.
 
virtual MergeSpecificationPtr findMergesForOptimize (const SegmentInfosPtr &segmentInfos, int32_t maxSegmentCount, SetSegmentInfo segmentsToOptimize)
 Returns the merges necessary to optimize the index. This merge policy defines "optimized" to mean only one segment in the index, where that segment has no deletions pending nor separate norms, and it is in compound file format if the current useCompoundFile setting is true. This method returns multiple merges (mergeFactor at a time) so the MergeScheduler in use may make use of concurrency.
 
virtual MergeSpecificationPtr findMergesToExpungeDeletes (const SegmentInfosPtr &segmentInfos)
 Finds merges necessary to expunge all deletes from the index. We simply merge adjacent segments that have deletes, up to mergeFactor at a time.
 
virtual MergeSpecificationPtr findMerges (const SegmentInfosPtr &segmentInfos)
 Checks if any merges are now necessary and returns a MergePolicy.MergeSpecification if so. A merge is necessary when there are more than setMergeFactor segments at a given level. When multiple levels have too many segments, this method will return multiple merges, allowing the MergeScheduler to use concurrency.
 
void setMaxMergeDocs (int32_t maxMergeDocs)
 Determines the largest segment (measured by document count) that may be merged with other segments. Small values (eg., less than 10,000) are best for interactive indexing, as this limits the length of pauses while indexing to a few seconds. Larger values are best for batched indexing and speedier searches.
 
int32_t getMaxMergeDocs ()
 Returns the largest segment (measured by document count) that may be merged with other segments.
 
- Public Member Functions inherited from Lucene::MergePolicy
 MergePolicy (const IndexWriterPtr &writer)
 
virtual ~MergePolicy ()
 
boost::shared_ptr< MergePolicyshared_from_this ()
 
- Public Member Functions inherited from Lucene::LuceneObject
virtual ~LuceneObject ()
 
virtual void initialize ()
 Called directly after instantiation to create objects that depend on this object being fully constructed.
 
virtual LuceneObjectPtr clone (const LuceneObjectPtr &other=LuceneObjectPtr())
 Return clone of this object.
 
virtual int32_t hashCode ()
 Return hash code for this object.
 
virtual bool equals (const LuceneObjectPtr &other)
 Return whether two objects are equal.
 
virtual int32_t compareTo (const LuceneObjectPtr &other)
 Compare two objects.
 
virtual String toString ()
 Returns a string representation of the object.
 
- Public Member Functions inherited from Lucene::LuceneSync
virtual ~LuceneSync ()
 
virtual SynchronizePtr getSync ()
 Return this object synchronize lock.
 
virtual LuceneSignalPtr getSignal ()
 Return this object signal.
 
virtual void lock (int32_t timeout=0)
 Lock this object using an optional timeout.
 
virtual void unlock ()
 Unlock this object.
 
virtual bool holdsLock ()
 Returns true if this object is currently locked by current thread.
 
virtual void wait (int32_t timeout=0)
 Wait for signal using an optional timeout.
 
virtual void notifyAll ()
 Notify all threads waiting for signal.
 

Static Public Member Functions

static String _getClassName ()
 
- Static Public Member Functions inherited from Lucene::MergePolicy
static String _getClassName ()
 

Data Fields

int64_t minMergeSize
 
int64_t maxMergeSize
 
int32_t maxMergeDocs
 

Static Public Attributes

static const double LEVEL_LOG_SPAN
 Defines the allowed range of log(size) for each level. A level is computed by taking the max segment log size, minus LEVEL_LOG_SPAN, and finding all segments falling within that range.
 
static const int32_t DEFAULT_MERGE_FACTOR
 Default merge factor, which is how many segments are merged at a time.
 
static const int32_t DEFAULT_MAX_MERGE_DOCS
 Default maximum segment size. A segment of this size or larger will never be merged.
 
static const double DEFAULT_NO_CFS_RATIO
 Default noCFSRatio. If a merge's size is >= 10% of the index, then we disable compound file for it.
 

Protected Member Functions

bool verbose ()
 
void message (const String &message)
 
virtual int64_t size (const SegmentInfoPtr &info)=0
 
int64_t sizeDocs (const SegmentInfoPtr &info)
 
int64_t sizeBytes (const SegmentInfoPtr &info)
 
bool isOptimized (const SegmentInfosPtr &infos, int32_t maxNumSegments, SetSegmentInfo segmentsToOptimize)
 
bool isOptimized (const SegmentInfoPtr &info)
 Returns true if this single info is optimized (has no pending norms or deletes, is in the same dir as the writer, and matches the current compound file setting.
 
OneMergePtr makeOneMerge (const SegmentInfosPtr &infos, const SegmentInfosPtr &infosToMerge)
 
- Protected Member Functions inherited from Lucene::LuceneObject
 LuceneObject ()
 

Protected Attributes

int32_t mergeFactor
 
double noCFSRatio
 
bool calibrateSizeByDeletes
 
bool _useCompoundFile
 
bool _useCompoundDocStore
 
- Protected Attributes inherited from Lucene::MergePolicy
IndexWriterWeakPtr _writer
 
- Protected Attributes inherited from Lucene::LuceneSync
SynchronizePtr objectLock
 
LuceneSignalPtr objectSignal
 

Detailed Description

This class implements a MergePolicy that tries to merge segments into levels of exponentially increasing size, where each level has fewer segments than the value of the merge factor. Whenever extra segments (beyond the merge factor upper bound) are encountered, all segments within the level are merged. You can get or set the merge factor using getMergeFactor() and setMergeFactor(int) respectively.

This class is abstract and requires a subclass to define the size method which specifies how a segment's size is determined. LogDocMergePolicy is one subclass that measures size by document count in the segment. LogByteSizeMergePolicy is another subclass that measures size as the total byte size of the file(s) for the segment.

Constructor & Destructor Documentation

◆ LogMergePolicy()

Lucene::LogMergePolicy::LogMergePolicy ( const IndexWriterPtr writer)

◆ ~LogMergePolicy()

virtual Lucene::LogMergePolicy::~LogMergePolicy ( )
virtual

Member Function Documentation

◆ _getClassName()

static String Lucene::LogMergePolicy::_getClassName ( )
inlinestatic

◆ close()

virtual void Lucene::LogMergePolicy::close ( )
virtual

Release all resources for the policy.

Implements Lucene::MergePolicy.

◆ findMerges()

virtual MergeSpecificationPtr Lucene::LogMergePolicy::findMerges ( const SegmentInfosPtr segmentInfos)
virtual

Checks if any merges are now necessary and returns a MergePolicy.MergeSpecification if so. A merge is necessary when there are more than setMergeFactor segments at a given level. When multiple levels have too many segments, this method will return multiple merges, allowing the MergeScheduler to use concurrency.

Implements Lucene::MergePolicy.

◆ findMergesForOptimize()

virtual MergeSpecificationPtr Lucene::LogMergePolicy::findMergesForOptimize ( const SegmentInfosPtr segmentInfos,
int32_t  maxSegmentCount,
SetSegmentInfo  segmentsToOptimize 
)
virtual

Returns the merges necessary to optimize the index. This merge policy defines "optimized" to mean only one segment in the index, where that segment has no deletions pending nor separate norms, and it is in compound file format if the current useCompoundFile setting is true. This method returns multiple merges (mergeFactor at a time) so the MergeScheduler in use may make use of concurrency.

Implements Lucene::MergePolicy.

◆ findMergesToExpungeDeletes()

virtual MergeSpecificationPtr Lucene::LogMergePolicy::findMergesToExpungeDeletes ( const SegmentInfosPtr segmentInfos)
virtual

Finds merges necessary to expunge all deletes from the index. We simply merge adjacent segments that have deletes, up to mergeFactor at a time.

Implements Lucene::MergePolicy.

◆ getCalibrateSizeByDeletes()

bool Lucene::LogMergePolicy::getCalibrateSizeByDeletes ( )

Returns true if the segment size should be calibrated by the number of deletes when choosing segments for merge.

◆ getClassName()

virtual String Lucene::LogMergePolicy::getClassName ( )
inlinevirtual

◆ getMaxMergeDocs()

int32_t Lucene::LogMergePolicy::getMaxMergeDocs ( )

Returns the largest segment (measured by document count) that may be merged with other segments.

See also
setMaxMergeDocs

◆ getMergeFactor()

int32_t Lucene::LogMergePolicy::getMergeFactor ( )

Returns the number of segments that are merged at once and also controls the total number of segments allowed to accumulate in the index.

◆ getNoCFSRatio()

double Lucene::LogMergePolicy::getNoCFSRatio ( )
See also
setNoCFSRatio

◆ getUseCompoundDocStore()

bool Lucene::LogMergePolicy::getUseCompoundDocStore ( )

Returns true if newly flushed and newly merge doc store segment files (term vectors and stored fields) are written in compound file format.

See also
setUseCompoundDocStore

◆ getUseCompoundFile()

bool Lucene::LogMergePolicy::getUseCompoundFile ( )

Returns true if newly flushed and newly merge segments are written in compound file format.

See also
setUseCompoundFile

◆ isOptimized() [1/2]

bool Lucene::LogMergePolicy::isOptimized ( const SegmentInfoPtr info)
protected

Returns true if this single info is optimized (has no pending norms or deletes, is in the same dir as the writer, and matches the current compound file setting.

◆ isOptimized() [2/2]

bool Lucene::LogMergePolicy::isOptimized ( const SegmentInfosPtr infos,
int32_t  maxNumSegments,
SetSegmentInfo  segmentsToOptimize 
)
protected

◆ makeOneMerge()

OneMergePtr Lucene::LogMergePolicy::makeOneMerge ( const SegmentInfosPtr infos,
const SegmentInfosPtr infosToMerge 
)
protected

◆ message()

void Lucene::LogMergePolicy::message ( const String &  message)
protected

◆ setCalibrateSizeByDeletes()

void Lucene::LogMergePolicy::setCalibrateSizeByDeletes ( bool  calibrateSizeByDeletes)

Sets whether the segment size should be calibrated by the number of deletes when choosing segments for merge.

◆ setMaxMergeDocs()

void Lucene::LogMergePolicy::setMaxMergeDocs ( int32_t  maxMergeDocs)

Determines the largest segment (measured by document count) that may be merged with other segments. Small values (eg., less than 10,000) are best for interactive indexing, as this limits the length of pauses while indexing to a few seconds. Larger values are best for batched indexing and speedier searches.

The default value is INT_MAX.

The default merge policy (LogByteSizeMergePolicy) also allows you to set this limit by net size (in MB) of the segment, using LogByteSizeMergePolicy#setMaxMergeMB.

◆ setMergeFactor()

void Lucene::LogMergePolicy::setMergeFactor ( int32_t  mergeFactor)

Determines how often segment indices are merged by addDocument(). With smaller values, less RAM is used while indexing, and searches on unoptimized indices are faster, but indexing speed is slower. With larger values, more RAM is used during indexing, and while searches on unoptimized indices are slower, indexing is faster. Thus larger values (> 10) are best for batch index creation, and smaller values (< 10) for indices that are interactively maintained.

◆ setNoCFSRatio()

void Lucene::LogMergePolicy::setNoCFSRatio ( double  noCFSRatio)

If a merged segment will be more than this percentage of the total size of the index, leave the segment as non-compound file even if compound file is enabled. Set to 1.0 to always use CFS regardless of merge size.

◆ setUseCompoundDocStore()

void Lucene::LogMergePolicy::setUseCompoundDocStore ( bool  useCompoundDocStore)

Sets whether compound file format should be used for newly flushed and newly merged doc store segment files (term vectors and stored fields).

◆ setUseCompoundFile()

void Lucene::LogMergePolicy::setUseCompoundFile ( bool  useCompoundFile)

Sets whether compound file format should be used for newly flushed and newly merged segments.

◆ shared_from_this()

boost::shared_ptr< LogMergePolicy > Lucene::LogMergePolicy::shared_from_this ( )
inline

◆ size()

virtual int64_t Lucene::LogMergePolicy::size ( const SegmentInfoPtr info)
protectedpure virtual

◆ sizeBytes()

int64_t Lucene::LogMergePolicy::sizeBytes ( const SegmentInfoPtr info)
protected

◆ sizeDocs()

int64_t Lucene::LogMergePolicy::sizeDocs ( const SegmentInfoPtr info)
protected

◆ useCompoundDocStore()

virtual bool Lucene::LogMergePolicy::useCompoundDocStore ( const SegmentInfosPtr segments)
virtual

Returns true if the doc store files should use the compound file format.

Implements Lucene::MergePolicy.

◆ useCompoundFile()

virtual bool Lucene::LogMergePolicy::useCompoundFile ( const SegmentInfosPtr segments,
const SegmentInfoPtr newSegment 
)
virtual

Returns true if a newly flushed (not from merge) segment should use the compound file format.

Implements Lucene::MergePolicy.

◆ verbose()

bool Lucene::LogMergePolicy::verbose ( )
protected

Field Documentation

◆ _useCompoundDocStore

bool Lucene::LogMergePolicy::_useCompoundDocStore
protected

◆ _useCompoundFile

bool Lucene::LogMergePolicy::_useCompoundFile
protected

◆ calibrateSizeByDeletes

bool Lucene::LogMergePolicy::calibrateSizeByDeletes
protected

◆ DEFAULT_MAX_MERGE_DOCS

const int32_t Lucene::LogMergePolicy::DEFAULT_MAX_MERGE_DOCS
static

Default maximum segment size. A segment of this size or larger will never be merged.

See also
setMaxMergeDocs

◆ DEFAULT_MERGE_FACTOR

const int32_t Lucene::LogMergePolicy::DEFAULT_MERGE_FACTOR
static

Default merge factor, which is how many segments are merged at a time.

◆ DEFAULT_NO_CFS_RATIO

const double Lucene::LogMergePolicy::DEFAULT_NO_CFS_RATIO
static

Default noCFSRatio. If a merge's size is >= 10% of the index, then we disable compound file for it.

See also
setNoCFSRatio

◆ LEVEL_LOG_SPAN

const double Lucene::LogMergePolicy::LEVEL_LOG_SPAN
static

Defines the allowed range of log(size) for each level. A level is computed by taking the max segment log size, minus LEVEL_LOG_SPAN, and finding all segments falling within that range.

◆ maxMergeDocs

int32_t Lucene::LogMergePolicy::maxMergeDocs

◆ maxMergeSize

int64_t Lucene::LogMergePolicy::maxMergeSize

◆ mergeFactor

int32_t Lucene::LogMergePolicy::mergeFactor
protected

◆ minMergeSize

int64_t Lucene::LogMergePolicy::minMergeSize

◆ noCFSRatio

double Lucene::LogMergePolicy::noCFSRatio
protected

The documentation for this class was generated from the following file:

clucene.sourceforge.net