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Public Member Functions | Static Public Member Functions | Protected Member Functions | Protected Attributes
Lucene::Analyzer Class Referenceabstract

An Analyzer builds TokenStreams, which analyze text. It thus represents a policy for extracting index terms from text. More...

#include <Analyzer.h>

+ Inheritance diagram for Lucene::Analyzer:

Public Member Functions

virtual ~Analyzer ()
 
virtual String getClassName ()
 
boost::shared_ptr< Analyzershared_from_this ()
 
virtual TokenStreamPtr tokenStream (const String &fieldName, const ReaderPtr &reader)=0
 Creates a TokenStream which tokenizes all the text in the provided Reader. Must be able to handle null field name for backward compatibility.
 
virtual TokenStreamPtr reusableTokenStream (const String &fieldName, const ReaderPtr &reader)
 Creates a TokenStream that is allowed to be re-used from the previous time that the same thread called this method. Callers that do not need to use more than one TokenStream at the same time from this analyzer should use this method for better performance.
 
virtual int32_t getPositionIncrementGap (const String &fieldName)
 Invoked before indexing a Fieldable instance if terms have already been added to that field. This allows custom analyzers to place an automatic position increment gap between Fieldable instances using the same field name. The default value position increment gap is 0. With a 0 position increment gap and the typical default token position increment of 1, all terms in a field, including across Fieldable instances, are in successive positions, allowing exact PhraseQuery matches, for instance, across Fieldable instance boundaries.
 
virtual int32_t getOffsetGap (const FieldablePtr &field)
 Just like getPositionIncrementGap, except for Token offsets instead. By default this returns 1 for tokenized fields and, as if the fields were joined with an extra space character, and 0 for un-tokenized fields. This method is only called if the field produced at least one token for indexing.
 
virtual void close ()
 Frees persistent resources used by this Analyzer.
 
- 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 ()
 

Protected Member Functions

virtual LuceneObjectPtr getPreviousTokenStream ()
 Used by Analyzers that implement reusableTokenStream to retrieve previously saved TokenStreams for re-use by the same thread.
 
virtual void setPreviousTokenStream (const LuceneObjectPtr &stream)
 Used by Analyzers that implement reusableTokenStream to save a TokenStream for later re-use by the same thread.
 
- Protected Member Functions inherited from Lucene::LuceneObject
 LuceneObject ()
 

Protected Attributes

CloseableThreadLocal< LuceneObjecttokenStreams
 
- Protected Attributes inherited from Lucene::LuceneSync
SynchronizePtr objectLock
 
LuceneSignalPtr objectSignal
 

Detailed Description

An Analyzer builds TokenStreams, which analyze text. It thus represents a policy for extracting index terms from text.

Typical implementations first build a Tokenizer, which breaks the stream of characters from the Reader into raw Tokens. One or more TokenFilters may then be applied to the output of the Tokenizer.

Constructor & Destructor Documentation

◆ ~Analyzer()

virtual Lucene::Analyzer::~Analyzer ( )
virtual

Member Function Documentation

◆ _getClassName()

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

◆ close()

virtual void Lucene::Analyzer::close ( )
virtual

Frees persistent resources used by this Analyzer.

◆ getClassName()

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

◆ getOffsetGap()

virtual int32_t Lucene::Analyzer::getOffsetGap ( const FieldablePtr field)
virtual

Just like getPositionIncrementGap, except for Token offsets instead. By default this returns 1 for tokenized fields and, as if the fields were joined with an extra space character, and 0 for un-tokenized fields. This method is only called if the field produced at least one token for indexing.

Parameters
fieldthe field just indexed
Returns
offset gap, added to the next token emitted from tokenStream(String,Reader)

Reimplemented in Lucene::PerFieldAnalyzerWrapper.

◆ getPositionIncrementGap()

virtual int32_t Lucene::Analyzer::getPositionIncrementGap ( const String &  fieldName)
virtual

Invoked before indexing a Fieldable instance if terms have already been added to that field. This allows custom analyzers to place an automatic position increment gap between Fieldable instances using the same field name. The default value position increment gap is 0. With a 0 position increment gap and the typical default token position increment of 1, all terms in a field, including across Fieldable instances, are in successive positions, allowing exact PhraseQuery matches, for instance, across Fieldable instance boundaries.

Parameters
fieldNameFieldable name being indexed.
Returns
position increment gap, added to the next token emitted from tokenStream(String,Reader)

Reimplemented in Lucene::PerFieldAnalyzerWrapper.

◆ getPreviousTokenStream()

virtual LuceneObjectPtr Lucene::Analyzer::getPreviousTokenStream ( )
protectedvirtual

Used by Analyzers that implement reusableTokenStream to retrieve previously saved TokenStreams for re-use by the same thread.

◆ reusableTokenStream()

virtual TokenStreamPtr Lucene::Analyzer::reusableTokenStream ( const String &  fieldName,
const ReaderPtr reader 
)
virtual

Creates a TokenStream that is allowed to be re-used from the previous time that the same thread called this method. Callers that do not need to use more than one TokenStream at the same time from this analyzer should use this method for better performance.

Reimplemented in Lucene::KeywordAnalyzer, Lucene::PerFieldAnalyzerWrapper, Lucene::SimpleAnalyzer, Lucene::StandardAnalyzer, Lucene::StopAnalyzer, and Lucene::WhitespaceAnalyzer.

◆ setPreviousTokenStream()

virtual void Lucene::Analyzer::setPreviousTokenStream ( const LuceneObjectPtr stream)
protectedvirtual

Used by Analyzers that implement reusableTokenStream to save a TokenStream for later re-use by the same thread.

◆ shared_from_this()

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

◆ tokenStream()

virtual TokenStreamPtr Lucene::Analyzer::tokenStream ( const String &  fieldName,
const ReaderPtr reader 
)
pure virtual

Creates a TokenStream which tokenizes all the text in the provided Reader. Must be able to handle null field name for backward compatibility.

Implemented in Lucene::KeywordAnalyzer, Lucene::PerFieldAnalyzerWrapper, Lucene::SimpleAnalyzer, Lucene::StandardAnalyzer, Lucene::StopAnalyzer, and Lucene::WhitespaceAnalyzer.

Field Documentation

◆ tokenStreams

CloseableThreadLocal<LuceneObject> Lucene::Analyzer::tokenStreams
protected

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

clucene.sourceforge.net