Defines a strus information retrieval query. More...

#include <queryInterface.hpp>

Public Member Functions
virtual	~QueryInterface ()
	Destructor. More...

virtual void	pushTerm (const std::string &type_, const std::string &value_, const Index &length_)=0
	Push a term to the query stack. More...

virtual void	pushDocField (const std::string &metadataRangeStart, const std::string &metadataRangeEnd)=0
	Push an expression on the query stack that defines a single field per document. The fields are represented as a sets of postings. The postings are defined as meta data elements describing the start and the end of the field for each document. More...

virtual void	pushExpression (const PostingJoinOperatorInterface *operation, unsigned int argc, int range, unsigned int cardinality)=0
	Push an expression formed by the topmost elements from the stack to the query stack, removing the argument elements. More...

virtual void	attachVariable (const std::string &name_)=0
	Attaches a variable to the top expression or term on the query stack. More...

virtual void	defineFeature (const std::string &set_, double weight_=1.0)=0
	Define the topmost element of the stack as feature, removing it from the stack. More...

virtual void	defineTermStatistics (const std::string &type_, const std::string &value_, const TermStatistics &stats_)=0
	Define the statistics of a term for the case that they are defined by the client (for example in a system with a distributed index) More...

virtual void	defineGlobalStatistics (const GlobalStatistics &stats_)=0
	Define the global statistics for the case that they are defined by the client. More...

virtual void	addMetaDataRestrictionCondition (const MetaDataRestrictionInterface::CompareOperator &opr, const std::string &name, const NumericVariant &operand, bool newGroup=true)=0
	Add a condition clause to the restriction on the document meta data of this query. More...

virtual void	addDocumentEvaluationSet (const std::vector< Index > &docnolist_)=0
	Define a restriction on the documents as list of local document numbers (Add local document numbers to the list of documents to restrict the query on) More...

virtual void	addAccess (const std::string &username_)=0
	Add a restriction for documents accessible by this query. More...

virtual void	setMaxNofRanks (std::size_t maxNofRanks_)=0
	Set the maximum number of ranks to evaluate starting with the minimum rank. More...

virtual void	setMinRank (std::size_t minRank_)=0
	Set the minimum rank number to return. More...

virtual void	setWeightingVariableValue (const std::string &name, double value)=0
	Set the value of a variable in the weigthing formula defined with QueryEval::defineWeightingFormula(ScalarFunctionInterface* combinefunc) or in a weighting function or a summarizer. More...

virtual void	setDebugMode (bool debug)=0
	Switch debug mode on or off (default off). In case of debug mode additional attributes defined with the function definitions in the query evaluation are attached to the result. More...

virtual QueryResult	evaluate () const =0
	Evaluate the query. More...

virtual std::string	tostring () const =0
	Map query to readable string. More...

Detailed Description

Defines a strus information retrieval query.

Constructor & Destructor Documentation

virtual strus::QueryInterface::~QueryInterface ( )

inlinevirtual

Destructor.

Member Function Documentation

virtual void strus::QueryInterface::addAccess ( const std::string & username_ )

pure virtual

Add a restriction for documents accessible by this query.

Parameters

[in] username_ name of user role that is allowed to see the result documents

virtual void strus::QueryInterface::addDocumentEvaluationSet ( const std::vector< Index > & docnolist_ )

pure virtual

Define a restriction on the documents as list of local document numbers (Add local document numbers to the list of documents to restrict the query on)

Parameters

[in] docnolist_ list of documents to evaluate the query on

virtual void strus::QueryInterface::addMetaDataRestrictionCondition	(	const MetaDataRestrictionInterface::CompareOperator &	opr,
		const std::string &	name,
		const NumericVariant &	operand,
		bool	newGroup = `true`
	)

pure virtual

Add a condition clause to the restriction on the document meta data of this query.

Parameters

[in]	opr	condition compare operator
[in]	name	name of meta data element to check
[in]	operand	constant number to check against
[in]	newGroup	true, if the conditional opens a new group of elements joined with a logical "OR" false, if the conditional belongs to the last group of elements joined with a logical "OR". Different groups are joined with a logical "AND" to form the meta data restriction expression

virtual void strus::QueryInterface::attachVariable ( const std::string & name_ )

pure virtual

Attaches a variable to the top expression or term on the query stack.

Note: The positions of the query matches of the referenced term or expression can be accessed through this variable in summarization.

Parameters

[in] name_ name of the variable attached

Remarks: The stack is not changed; More than one variable can be attached

virtual void strus::QueryInterface::defineFeature	(	const std::string &	set_,
		double	weight_ = `1.0`
	)

pure virtual

Define the topmost element of the stack as feature, removing it from the stack.

Parameters

[in]	set_	name of the set of the new feature created
[in]	weight_	weight of the feature for the weighting function in query evaluation

virtual void strus::QueryInterface::defineGlobalStatistics ( const GlobalStatistics & stats_ )

pure virtual

Define the global statistics for the case that they are defined by the client.

Parameters

[in] stats_ global statistics

virtual void strus::QueryInterface::defineTermStatistics	(	const std::string &	type_,
		const std::string &	value_,
		const TermStatistics &	stats_
	)

pure virtual

Define the statistics of a term for the case that they are defined by the client (for example in a system with a distributed index)

Parameters

[in]	type_	term type
[in]	value_	term value
[in]	stats_	term statistics

virtual QueryResult strus::QueryInterface::evaluate ( ) const

pure virtual

Evaluate the query.

Returns: result of query evaluation

virtual void strus::QueryInterface::pushDocField	(	const std::string &	metadataRangeStart,
		const std::string &	metadataRangeEnd
	)

pure virtual

Push an expression on the query stack that defines a single field per document. The fields are represented as a sets of postings. The postings are defined as meta data elements describing the start and the end of the field for each document.

Parameters

[in]	metadataRangeStart	name of metadata element that defines the start position of the field in a document
[in]	metadataRangeEnd	name of metadata element that defines the end position of the field (first position after the field) in a document

Note: fields can be used to identify elements in a certain document area without access of posting blocks and without assigning a different feature type and thus having different statistics

virtual void strus::QueryInterface::pushExpression	(	const PostingJoinOperatorInterface *	operation,
		unsigned int	argc,
		int	range,
		unsigned int	cardinality
	)

pure virtual

Push an expression formed by the topmost elements from the stack to the query stack, removing the argument elements.

Parameters

[in]	operation	the expression join operator
[in]	argc	number of expression arguments
[in]	range	position proximity range of the expression
[in]	cardinality	specifies a result dimension requirement (e.g. minimum number of elements of any input subset selection that builds a result) (0 for use default). Interpretation depends on operation, but in most cases it specifies the required size for a valid result.

virtual void strus::QueryInterface::pushTerm	(	const std::string &	type_,
		const std::string &	value_,
		const Index &	length_
	)

pure virtual

Push a term to the query stack.

Parameters

[in]	type_	term type
[in]	value_	term value
[in]	length_	term length (ordinal position count)

virtual void strus::QueryInterface::setDebugMode ( bool debug )

pure virtual

Switch debug mode on or off (default off). In case of debug mode additional attributes defined with the function definitions in the query evaluation are attached to the result.

Parameters

[in] debug true for enabling debug mode on and false for disabling debug mode (diabled by default)

virtual void strus::QueryInterface::setMaxNofRanks ( std::size_t maxNofRanks_ )

pure virtual

Set the maximum number of ranks to evaluate starting with the minimum rank.

Parameters

[in] maxNofRanks_ maximum number of ranks

virtual void strus::QueryInterface::setMinRank ( std::size_t minRank_ )

pure virtual

Set the minimum rank number to return.

Parameters

[in] minRank_ the minimum rank number

virtual void strus::QueryInterface::setWeightingVariableValue	(	const std::string &	name,
		double	value
	)

pure virtual

Set the value of a variable in the weigthing formula defined with QueryEval::defineWeightingFormula(ScalarFunctionInterface* combinefunc) or in a weighting function or a summarizer.

Parameters

[in]	name	name of the variable
[in]	value	value of the variable

virtual std::string strus::QueryInterface::tostring ( ) const

pure virtual

Map query to readable string.

Returns: query with query evaluation scheme in readable form

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

/home/patrick/Projects/github/strus/include/strus/queryInterface.hpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation