Base class for classes which filter another PostList. More...

#include <selectpostlist.h>

Inheritance diagram for SelectPostList:

Collaboration diagram for SelectPostList:

Public Member Functions
	SelectPostList (PostList pl_, EstimateOp estimate_op_, PostListTree *pltree_)

	~SelectPostList ()

double	get_weight (Xapian::termcount doclen, Xapian::termcount unique_terms, Xapian::termcount wdfdocmax) const
	Return the weight contribution for the current position. More...

bool	at_end () const
	Return true if the current position is past the last entry in this list. More...

PostList *	next (double w_min)
	Advance the current position to the next document in the postlist. More...

PostList *	skip_to (Xapian::docid did, double w_min)
	Skip forward to the specified docid. More...

PostList *	check (Xapian::docid did, double w_min, bool &valid)
	Check if the specified docid occurs in this postlist. More...

Public Member Functions inherited from WrapperPostList
	WrapperPostList (PostList *pl_)

	~WrapperPostList ()

Xapian::docid	get_docid () const
	Return the current docid. More...

double	get_weight (Xapian::termcount doclen, Xapian::termcount unique_terms, Xapian::termcount wdfdocmax) const
	Return the weight contribution for the current position. More...

bool	at_end () const
	Return true if the current position is past the last entry in this list. More...

double	recalc_maxweight ()
	Recalculate the upper bound on what get_weight() can return. More...

PositionList *	read_position_list ()
	Read the position list for the term in the current document and return a pointer to it (owned by the PostList). More...

PostList *	next (double w_min)
	Advance the current position to the next document in the postlist. More...

PostList *	skip_to (Xapian::docid, double w_min)
	Skip forward to the specified docid. More...

std::string	get_description () const
	Return a string description of this object. More...

Xapian::termcount	get_wdf () const
	Return the wdf for the document at the current position. More...

Xapian::termcount	count_matching_subqs () const
	Count the number of leaf subqueries which match at the current position. More...

Public Member Functions inherited from Xapian::Internal::PostList
virtual	~PostList ()
	We have virtual methods and want to be able to delete derived classes using a pointer to the base class, so we need a virtual destructor. More...

Xapian::doccount	get_termfreq () const
	Get an estimate of the number of documents this PostList will return. More...

virtual PositionList *	open_position_list () const
	Read the position list for the term in the current document and return a pointer to it (not owned by the PostList). More...

PostList *	next ()
	Advance the current position to the next document in the postlist. More...

PostList *	skip_to (Xapian::docid did)
	Skip forward to the specified docid. More...

virtual void	gather_position_lists (OrPositionList *orposlist)
	Gather PositionList* objects for a subtree. More...

virtual void	get_docid_range (docid &first, docid &last) const
	Get the bounds on the range of docids this PostList can return. More...

Protected Member Functions
virtual bool	test_doc ()=0
	Check if the current document should be selected. More...

Protected Member Functions inherited from Xapian::Internal::PostList
	PostList ()
	Only constructable as a base class for derived classes. More...

Protected Attributes
Xapian::doccount	accepted = 0
	Number of times test_doc() returned true. More...

Xapian::doccount	rejected = 0
	Number of times test_doc() returned false. More...

EstimateOp *	estimate_op
	Object to report accepted/rejected counts to. More...

Protected Attributes inherited from WrapperPostList
PostList *	pl

Protected Attributes inherited from Xapian::Internal::PostList
Xapian::doccount	termfreq
	Estimate of the number of documents this PostList will return. More...

Private Member Functions
bool	vet (double w_min)
	Check if the current document is suitable. More...

Private Attributes
double	cached_weight = -HUGE_VAL
	Used to avoid calculating the weight twice for a given document. More...

PostListTree *	pltree

Detailed Description

Base class for classes which filter another PostList.

Definition at line 32 of file selectpostlist.h.

Constructor & Destructor Documentation

◆ SelectPostList()

SelectPostList::SelectPostList	(	PostList *	pl_,
		EstimateOp *	estimate_op_,
		PostListTree *	pltree_
	)

inline

Definition at line 55 of file selectpostlist.h.

◆ ~SelectPostList()

SelectPostList::~SelectPostList ( )

Definition at line 54 of file selectpostlist.cc.

References accepted, estimate_op, rejected, and EstimateOp::report_ratio().

Member Function Documentation

◆ at_end()

bool SelectPostList::at_end ( ) const

virtual

Return true if the current position is past the last entry in this list.

Implements Xapian::Internal::PostList.

Definition at line 76 of file selectpostlist.cc.

References WrapperPostList::pl.

◆ check()

PostList * SelectPostList::check	(	Xapian::docid	did,
		double	w_min,
		bool &	valid
	)

virtual

Check if the specified docid occurs in this postlist.

The caller is required to ensure that the specified docid actually exists in the database.

This method acts like skip_to() if that can be done at little extra cost, in which case it then sets valid to true.

Otherwise it simply checks if a particular docid is present. If it is, valid is set to true. If it isn't, it sets valid to false, and leaves the position unspecified (and hence the result of calling methods which depend on the current position, such as get_docid() and at_end(), are also unspecified). In this state, next() will advance to the first matching position after docid, and skip_to() will act as it would if the position was the first matching position after docid. If valid is set to false, then NULL must be returned (pruning in this situation doesn't make sense).

The default implementation calls skip_to().

Reimplemented from Xapian::Internal::PostList.

Definition at line 112 of file selectpostlist.cc.

References Xapian::Internal::PostList::check(), WrapperPostList::pl, and vet().

◆ get_weight()

double SelectPostList::get_weight	(	Xapian::termcount	doclen,
		Xapian::termcount	unique_terms,
		Xapian::termcount	wdfdocmax
	)		const

virtual

Return the weight contribution for the current position.

Implements Xapian::Internal::PostList.

Definition at line 66 of file selectpostlist.cc.

References cached_weight, Xapian::Internal::PostList::get_weight(), and WrapperPostList::pl.

◆ next()

PostList * SelectPostList::next ( double w_min )

virtual

Advance the current position to the next document in the postlist.

The list starts before the first entry in the list, so next(), skip_to() or check() must be called before any methods which need the context of the current position.

Parameters

w_min The minimum weight contribution that is needed (this is just a hint which PostList subclasses may ignore).

Returns: If a non-NULL pointer is returned, then the caller should substitute the returned pointer for its pointer to us, and then delete us. This "pruning" can only happen for a non-leaf subclass of this class.

Implements Xapian::Internal::PostList.

Definition at line 82 of file selectpostlist.cc.

References Xapian::Internal::PostList::next(), WrapperPostList::pl, and vet().

◆ skip_to()

PostList * SelectPostList::skip_to	(	Xapian::docid	did,
		double	w_min
	)

virtual

Skip forward to the specified docid.

If the specified docid isn't in the list, position ourselves on the first document after it (or at_end() if no greater docids are present).

Parameters

w_min The minimum weight contribution that is needed (this is just a hint which PostList subclasses may ignore).

Returns: If a non-NULL pointer is returned, then the caller should substitute the returned pointer for its pointer to us, and then delete us. This "pruning" can only happen for a non-leaf subclass of this class.

Implements Xapian::Internal::PostList.

Definition at line 95 of file selectpostlist.cc.

References Xapian::Internal::PostList::get_docid(), Xapian::Internal::PostList::next(), WrapperPostList::pl, Xapian::Internal::PostList::skip_to(), and vet().

Referenced by ExactPhrasePostList::test_doc(), NearPostList::test_doc(), and PhrasePostList::test_doc().

◆ test_doc()

virtual bool SelectPostList::test_doc ( )

protectedpure virtual

Check if the current document should be selected.

Implemented in PhrasePostList, NearPostList, ExactPhrasePostList, and DeciderPostList.

Referenced by vet().

◆ vet()

bool SelectPostList::vet ( double w_min )

private

Check if the current document is suitable.

Definition at line 30 of file selectpostlist.cc.

References Xapian::Internal::PostList::at_end(), cached_weight, PostListTree::get_doc_stats(), Xapian::Internal::PostList::get_docid(), Xapian::Internal::PostList::get_weight(), WrapperPostList::pl, pltree, and test_doc().

Referenced by check(), next(), and skip_to().

Member Data Documentation

◆ accepted

Xapian::doccount SelectPostList::accepted = 0

protected

Number of times test_doc() returned true.

Definition at line 43 of file selectpostlist.h.

Referenced by ExactPhrasePostList::test_doc(), NearPostList::test_doc(), PhrasePostList::test_doc(), and ~SelectPostList().

◆ cached_weight

double SelectPostList::cached_weight = -HUGE_VAL

private

Used to avoid calculating the weight twice for a given document.

Definition at line 34 of file selectpostlist.h.

Referenced by get_weight(), and vet().

◆ estimate_op

EstimateOp* SelectPostList::estimate_op

protected

Object to report accepted/rejected counts to.

Definition at line 49 of file selectpostlist.h.

Referenced by ~SelectPostList().

◆ pltree

PostListTree* SelectPostList::pltree

private

Definition at line 36 of file selectpostlist.h.

Referenced by vet().

◆ rejected

Xapian::doccount SelectPostList::rejected = 0

protected

Number of times test_doc() returned false.

Definition at line 46 of file selectpostlist.h.

Referenced by ExactPhrasePostList::test_doc(), NearPostList::test_doc(), PhrasePostList::test_doc(), and ~SelectPostList().

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

matcher/selectpostlist.h
matcher/selectpostlist.cc

Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ SelectPostList()

◆ ~SelectPostList()

Member Function Documentation

◆ at_end()

◆ check()

◆ get_weight()

◆ next()

◆ skip_to()

◆ test_doc()

◆ vet()

Member Data Documentation

◆ accepted

◆ cached_weight

◆ estimate_op

◆ pltree

◆ rejected