Postlist which matches terms occurring within a specified window. More...

#include <nearpostlist.h>

Inheritance diagram for NearPostList:

Collaboration diagram for NearPostList:

Public Member Functions
	NearPostList (PostList source_, Xapian::termpos window_, const std::vector< PostList >::const_iterator &terms_begin, const std::vector< PostList *>::const_iterator &terms_end)

	~NearPostList ()

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

Xapian::doccount	get_termfreq_est () const
	Get an estimate of the number of documents indexed by this term. More...

TermFreqs	get_termfreq_est_using_stats (const Xapian::Weight::Internal &stats) const
	Get an estimate for the termfreq and reltermfreq, given the stats. More...

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

Public Member Functions inherited from SelectPostList
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...

Xapian::doccount	get_termfreq_max () const
	Get an upper bound on the number of documents indexed by this term. More...

Xapian::doccount	get_termfreq_min () const
	Get a lower bound on the number of documents indexed by this term. More...

double	get_maxweight () const
	Return an upper bound on what get_weight() can return. More...

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

double	get_weight () const
	Return the weight contribution for the current position. More...

Xapian::termcount	get_doclength () const
	Return the length of current document. More...

Xapian::termcount	get_unique_terms () const
	Return the number of unique terms in the current document. 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...

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...

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

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

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

	SelectPostList (PostList *source_)

	~SelectPostList ()

Public Member Functions inherited from Xapian::PostingIterator::Internal
virtual	~Internal ()
	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...

virtual const std::string *	get_sort_key () const

virtual const std::string *	get_collapse_key () const
	If the collapse key is already known, return it. More...

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

Internal *	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...

Public Member Functions inherited from Xapian::Internal::intrusive_base
	intrusive_base ()
	Construct with no references. More...

Private Member Functions
bool	test_doc ()
	Test if the current document contains the terms within the window. More...

Private Attributes
Xapian::termpos	window

std::vector< PostList * >	terms

PositionList **	poslists

Additional Inherited Members
Public Attributes inherited from Xapian::Internal::intrusive_base
unsigned	_refs
	Reference count. More...

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

Protected Attributes inherited from SelectPostList
PostList *	source

double	wt

Detailed Description

Postlist which matches terms occurring within a specified window.

NearPostList only returns a posting for documents contains all the terms (this part is implemented using an AndPostList) and additionally the terms occur somewhere in the document within a specified number of term positions.

The weight of a posting is the sum of the weights of the sub-postings (just like an AndPostList).

Definition at line 38 of file nearpostlist.h.

Constructor & Destructor Documentation

◆ NearPostList()

NearPostList::NearPostList	(	PostList *	source_,
		Xapian::termpos	window_,
		const std::vector< PostList *>::const_iterator &	terms_begin,
		const std::vector< PostList *>::const_iterator &	terms_end
	)

Definition at line 36 of file nearpostlist.cc.

References Assert, poslists, and terms.

◆ ~NearPostList()

NearPostList::~NearPostList ( )

Definition at line 47 of file nearpostlist.cc.

References poslists.

Member Function Documentation

◆ get_description()

string NearPostList::get_description ( ) const

virtual

Return a string description of this object.

Implements Xapian::PostingIterator::Internal.

Definition at line 224 of file nearpostlist.cc.

References Xapian::PostingIterator::Internal::get_description(), SelectPostList::source, Xapian::Internal::str(), and window.

◆ get_termfreq_est()

Xapian::doccount NearPostList::get_termfreq_est ( ) const

virtual

Get an estimate of the number of documents indexed by this term.

It should always be true that: get_termfreq_min() <= get_termfreq_est() <= get_termfreq_max()

Implements Xapian::PostingIterator::Internal.

Definition at line 201 of file nearpostlist.cc.

References Xapian::PostingIterator::Internal::get_termfreq_est(), and SelectPostList::source.

◆ get_termfreq_est_using_stats()

TermFreqs NearPostList::get_termfreq_est_using_stats ( const Xapian::Weight::Internal & stats ) const

virtual

Get an estimate for the termfreq and reltermfreq, given the stats.

The frequencies may be for a combination of databases, or for just the relevant documents, so the results need not lie in the bounds given by get_termfreq_min() and get_termfreq_max().

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 210 of file nearpostlist.cc.

References Xapian::PostingIterator::Internal::get_termfreq_est_using_stats(), LOGCALL, RETURN, SelectPostList::source, and TermFreqs::termfreq.