A postlist comprising two postlists ORed together. More...

#include <orpostlist.h>

Inheritance diagram for OrPostList:

Collaboration diagram for OrPostList:

Public Member Functions
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...

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...

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

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

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

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

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

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

virtual Xapian::termcount	get_doclength () const
	Return the document length of the document the current term comes from. More...

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

	OrPostList (PostList left_, PostList right_, MultiMatch *matcher_, Xapian::doccount dbsize_)

Xapian::termcount	get_wdf () const
	get_wdf() for OR postlists returns the sum of the wdfs of the sub postlists which are at the current document - this is desirable when the OR is part of a synonym. More...

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

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

Public Member Functions inherited from BranchPostList
	BranchPostList (PostList l_, PostList r_, MultiMatch *matcher_)

virtual	~BranchPostList ()

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...

virtual 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...

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...

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...

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

Private Attributes
Xapian::docid	lhead

Xapian::docid	rhead

bool	lvalid

bool	rvalid

double	lmax

double	rmax

double	minmax

Xapian::doccount	dbsize

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

Protected Member Functions inherited from BranchPostList
void	handle_prune (PostList &kid, PostList ret)
	Utility method, to call recalc_maxweight() and do the pruning if a next() or skip_to() returns non-NULL result. More...

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

Protected Attributes inherited from BranchPostList
PostList *	l
	Left sub-postlist. More...

PostList *	r
	Right sub-postlist. More...

MultiMatch *	matcher
	The object which is using this postlist to perform a match. More...

Detailed Description

A postlist comprising two postlists ORed together.

This postlist returns a posting if it is in either of the sub-postlists. The weight for a posting is the sum of the weights of the sub-postings, if both exist, or the sum of the single sub-posting which exists otherwise.

Definition at line 38 of file orpostlist.h.

Constructor & Destructor Documentation

◆ OrPostList()

OrPostList::OrPostList	(	PostList *	left_,
		PostList *	right_,
		MultiMatch *	matcher_,
		Xapian::doccount	dbsize_
	)

Definition at line 38 of file orpostlist.cc.

References AssertRel, Xapian::PostingIterator::Internal::get_termfreq_est(), and LOGCALL_CTOR.

Member Function Documentation

◆ at_end()

bool OrPostList::at_end ( ) const

virtual

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

Implements Xapian::PostingIterator::Internal.

Definition at line 385 of file orpostlist.cc.

References AssertParanoid, Xapian::PostingIterator::Internal::at_end(), BranchPostList::l, LOGCALL, BranchPostList::r, and RETURN.

◆ check()

PostList * OrPostList::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::PostingIterator::Internal.

Definition at line 196 of file orpostlist.cc.

References Assert, Xapian::PostingIterator::Internal::at_end(), check_handling_prune(), dbsize, Xapian::PostingIterator::Internal::get_docid(), BranchPostList::handle_prune(), BranchPostList::l, lhead, lmax, LOGCALL, LOGLINE, lvalid, BranchPostList::matcher, minmax, BranchPostList::r, RETURN, rhead, rmax, rvalid, and AndMaybePostList::sync_rhs().

◆ count_matching_subqs()

Xapian::termcount OrPostList::count_matching_subqs ( ) const

virtual

Count the number of leaf subqueries which match at the current position.

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 449 of file orpostlist.cc.

References Xapian::PostingIterator::Internal::count_matching_subqs(), BranchPostList::l, lhead, LOGCALL, BranchPostList::r, RETURN, and rhead.

◆ gather_position_lists()

void OrPostList::gather_position_lists ( OrPositionList * orposlist )

virtual

Gather PositionList* objects for a subtree.

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 458 of file orpostlist.cc.

References Xapian::PostingIterator::Internal::gather_position_lists(), BranchPostList::l, lhead, BranchPostList::r, and rhead.

◆ get_description()

std::string OrPostList::get_description ( ) const

virtual

Return a string description of this object.

Implements Xapian::PostingIterator::Internal.

Definition at line 394 of file orpostlist.cc.

References Xapian::PostingIterator::Internal::get_description(), BranchPostList::l, and BranchPostList::r.

◆ get_docid()

Xapian::docid OrPostList::get_docid ( ) const

virtual

Return the current docid.

Implements Xapian::PostingIterator::Internal.

Definition at line 345 of file orpostlist.cc.

References Assert, lhead, LOGCALL, RETURN, and rhead.

◆ get_doclength()

Xapian::termcount OrPostList::get_doclength ( ) const

virtual

Return the document length of the document the current term comes from.

This is obtained by asking the subpostlist which contains the current document for the document length. If both subpostlists are valid, the left one is asked.

Implements Xapian::PostingIterator::Internal.

Definition at line 400 of file orpostlist.cc.

References Assert, Xapian::PostingIterator::Internal::get_doclength(), BranchPostList::l, lhead, LOGCALL, LOGLINE, BranchPostList::r, RETURN, and rhead.

◆ get_maxweight()

double OrPostList::get_maxweight ( ) const

virtual

Return an upper bound on what get_weight() can return.

Implements Xapian::PostingIterator::Internal.

Definition at line 365 of file orpostlist.cc.

References lmax, LOGCALL, RETURN, and rmax.

Referenced by recalc_maxweight().

◆ get_termfreq_est()

Xapian::doccount OrPostList::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 291 of file orpostlist.cc.

References dbsize, est(), Xapian::PostingIterator::Internal::get_termfreq_est(), BranchPostList::l, LOGCALL, BranchPostList::r, rare, and RETURN.

◆ get_termfreq_est_using_stats()

TermFreqs OrPostList::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 312 of file orpostlist.cc.

References Assert, Xapian::Weight::Internal::collection_size, est(), Xapian::PostingIterator::Internal::get_termfreq_est_using_stats(), BranchPostList::l, LOGCALL, BranchPostList::r, RETURN, Xapian::Weight::Internal::rset_size, and Xapian::Weight::Internal::total_length.

◆ get_termfreq_max()

Xapian::doccount OrPostList::get_termfreq_max ( ) const

virtual

Get an upper bound on the number of documents indexed by this term.

Implements Xapian::PostingIterator::Internal.

Definition at line 277 of file orpostlist.cc.

References dbsize, Xapian::PostingIterator::Internal::get_termfreq_max(), BranchPostList::l, LOGCALL, BranchPostList::r, and RETURN.

◆ get_termfreq_min()

Xapian::doccount OrPostList::get_termfreq_min ( ) const

virtual

Get a lower bound on the number of documents indexed by this term.

Implements Xapian::PostingIterator::Internal.

Definition at line 284 of file orpostlist.cc.

References Xapian::PostingIterator::Internal::get_termfreq_min(), BranchPostList::l, LOGCALL, BranchPostList::r, and RETURN.

◆ get_unique_terms()

Xapian::termcount OrPostList::get_unique_terms ( ) const

virtual

Return the number of unique terms in the document.

Implements Xapian::PostingIterator::Internal.

Definition at line 420 of file orpostlist.cc.

References Assert, Xapian::PostingIterator::Internal::get_unique_terms(), BranchPostList::l, lhead, LOGCALL, LOGLINE, BranchPostList::r, RETURN, and rhead.

◆ get_wdf()

Xapian::termcount OrPostList::get_wdf ( ) const

virtual

get_wdf() for OR postlists returns the sum of the wdfs of the sub postlists which are at the current document - this is desirable when the OR is part of a synonym.

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 440 of file orpostlist.cc.

References Xapian::PostingIterator::Internal::get_wdf(), BranchPostList::l, lhead, LOGCALL, BranchPostList::r, RETURN, and rhead.

◆ get_weight()

double OrPostList::get_weight ( ) const

virtual

Return the weight contribution for the current position.

Implements Xapian::PostingIterator::Internal.

Definition at line 354 of file orpostlist.cc.

References Assert, Xapian::PostingIterator::Internal::get_weight(), BranchPostList::l, lhead, LOGCALL, BranchPostList::r, RETURN, and rhead.

◆ next()

PostList * OrPostList::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::PostingIterator::Internal.

Definition at line 51 of file orpostlist.cc.

References Assert, Xapian::PostingIterator::Internal::at_end(), dbsize, Xapian::PostingIterator::Internal::get_docid(), BranchPostList::handle_prune(), BranchPostList::l, lhead, lmax, LOGCALL, LOGLINE, lvalid, BranchPostList::matcher, minmax, next_handling_prune(), BranchPostList::r, RETURN, rhead, rmax, rvalid, skip_to_handling_prune(), and AndMaybePostList::sync_rhs().

◆ recalc_maxweight()

double OrPostList::recalc_maxweight ( )

virtual

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

If the tree has pruned, get_maxweight() may use cached values. Calling this method instead forces a full recalculation.

Note that this method may be called after the postlist has reached the end. In this situation, the method should return 0.

Implements Xapian::PostingIterator::Internal.

Definition at line 372 of file orpostlist.cc.

References get_maxweight(), BranchPostList::l, lmax, LOGCALL, minmax, BranchPostList::r, Xapian::PostingIterator::Internal::recalc_maxweight(), RETURN, and rmax.

◆ skip_to()

PostList * OrPostList::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::PostingIterator::Internal.

Definition at line 131 of file orpostlist.cc.

References Assert, Xapian::PostingIterator::Internal::at_end(), dbsize, Xapian::PostingIterator::Internal::get_docid(), BranchPostList::handle_prune(), BranchPostList::l, lhead, lmax, LOGCALL, LOGLINE, lvalid, BranchPostList::matcher, minmax, BranchPostList::r, RETURN, rhead, rmax, rvalid, skip_to_handling_prune(), and AndMaybePostList::sync_rhs().

Member Data Documentation

◆ dbsize

Xapian::doccount OrPostList::dbsize

private

Definition at line 43 of file orpostlist.h.

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

◆ lhead

Xapian::docid OrPostList::lhead

private

Definition at line 40 of file orpostlist.h.

Referenced by check(), count_matching_subqs(), gather_position_lists(), get_docid(), get_doclength(), get_unique_terms(), get_wdf(), get_weight(), next(), and skip_to().

◆ lmax

double OrPostList::lmax

private

Definition at line 42 of file orpostlist.h.

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

◆ lvalid

bool OrPostList::lvalid

private

Definition at line 41 of file orpostlist.h.

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

◆ minmax

double OrPostList::minmax

private

Definition at line 42 of file orpostlist.h.

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

◆ rhead

Xapian::docid OrPostList::rhead

private

Definition at line 40 of file orpostlist.h.

Referenced by check(), count_matching_subqs(), gather_position_lists(), get_docid(), get_doclength(), get_unique_terms(), get_wdf(), get_weight(), next(), and skip_to().

◆ rmax

double OrPostList::rmax

private

Definition at line 42 of file orpostlist.h.

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

◆ rvalid

bool OrPostList::rvalid

private

Definition at line 41 of file orpostlist.h.

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

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

matcher/orpostlist.h
matcher/orpostlist.cc

Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ OrPostList()

Member Function Documentation

◆ at_end()

◆ check()

◆ count_matching_subqs()

◆ gather_position_lists()

◆ get_description()

◆ get_docid()

◆ get_doclength()

◆ get_maxweight()

◆ get_termfreq_est()

◆ get_termfreq_est_using_stats()

◆ get_termfreq_max()

◆ get_termfreq_min()

◆ get_unique_terms()

◆ get_wdf()

◆ get_weight()

◆ next()

◆ recalc_maxweight()

◆ skip_to()

Member Data Documentation

◆ dbsize

◆ lhead

◆ lmax

◆ lvalid

◆ minmax

◆ rhead

◆ rmax

◆ rvalid