PostList class implementing Query::OP_AND_MAYBE. More...

#include <andmaybepostlist.h>

Inheritance diagram for AndMaybePostList:

Collaboration diagram for AndMaybePostList:

Public Member Functions
	AndMaybePostList (PostList left, PostList right, PostListTree *pltree_)

	AndMaybePostList (PostList left, PostList right, double lmax, double rmax, PostListTree *pltree_)
	Construct as decay product from OrPostList. More...

	~AndMaybePostList ()

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...

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...

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...

void	gather_position_lists (OrPositionList *orposlist)
	Gather PositionList* objects for a subtree. 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	get_docid_range (docid &first, docid &last) const
	Get the bounds on the range of docids this PostList can return. More...

Private Member Functions
bool	maybe_matches () const
	Does r match at the current position? More...

PostList *	decay_to_and (Xapian::docid did, double w_min, bool *valid_ptr=NULL)

Private Attributes
PostList *	r
	Right-hand side of OP_MAYBE. More...

Xapian::docid	pl_did = 0
	Current docid from WrapperPostList's pl. More...

Xapian::docid	r_did = 0
	Current docid from r (or 0). More...

double	pl_max
	Current max weight from WrapperPostList's pl. More...

double	r_max
	Current max weight from r. More...

PostListTree *	pltree

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

Detailed Description

PostList class implementing Query::OP_AND_MAYBE.

Definition at line 28 of file andmaybepostlist.h.

Constructor & Destructor Documentation

◆ AndMaybePostList() [1/2]

AndMaybePostList::AndMaybePostList	(	PostList *	left,
		PostList *	right,
		PostListTree *	pltree_
	)

inline

Definition at line 54 of file andmaybepostlist.h.

◆ AndMaybePostList() [2/2]

AndMaybePostList::AndMaybePostList	(	PostList *	left,
		PostList *	right,
		double	lmax,
		double	rmax,
		PostListTree *	pltree_
	)

inline

Construct as decay product from OrPostList.

The first operation after such construction must be check() or skip_to().

Definition at line 63 of file andmaybepostlist.h.

◆ ~AndMaybePostList()

AndMaybePostList::~AndMaybePostList ( )

inline

Definition at line 72 of file andmaybepostlist.h.

References r.

Member Function Documentation

◆ check()

PostList * AndMaybePostList::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 159 of file andmaybepostlist.cc.

References Xapian::Internal::PostList::check(), and Xapian::Internal::PostList::get_docid().

◆ count_matching_subqs()

Xapian::termcount AndMaybePostList::count_matching_subqs ( ) const

virtual

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

Reimplemented from Xapian::Internal::PostList.

Definition at line 219 of file andmaybepostlist.cc.

◆ decay_to_and()

PostList * AndMaybePostList::decay_to_and	(	Xapian::docid	did,
		double	w_min,
		bool *	valid_ptr = `NULL`
	)

private

Definition at line 30 of file andmaybepostlist.cc.

References Xapian::Internal::PostList::check(), and Xapian::Internal::PostList::skip_to().

◆ gather_position_lists()

void AndMaybePostList::gather_position_lists ( OrPositionList * orposlist )

virtual

Gather PositionList* objects for a subtree.

Reimplemented from Xapian::Internal::PostList.

Definition at line 228 of file andmaybepostlist.cc.

◆ get_description()

string AndMaybePostList::get_description ( ) const

virtual

Return a string description of this object.

Implements Xapian::Internal::PostList.

Definition at line 199 of file andmaybepostlist.cc.

◆ get_docid()

Xapian::docid AndMaybePostList::get_docid ( ) const

virtual

Return the current docid.

Implements Xapian::Internal::PostList.

Definition at line 51 of file andmaybepostlist.cc.

◆ get_wdf()

Xapian::termcount AndMaybePostList::get_wdf ( ) const

virtual

Return the wdf for the document at the current position.

The default implementation throws Xapian::UnimplementedError.

Reimplemented from Xapian::Internal::PostList.

Definition at line 210 of file andmaybepostlist.cc.

◆ get_weight()

double AndMaybePostList::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 57 of file andmaybepostlist.cc.

◆ maybe_matches()

bool AndMaybePostList::maybe_matches ( ) const

inlineprivate

Does r match at the current position?

Definition at line 47 of file andmaybepostlist.h.

References pl_did, and r_did.

◆ next()

PostList * AndMaybePostList::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 76 of file andmaybepostlist.cc.

References Xapian::Internal::PostList::check(), Xapian::Internal::PostList::get_docid(), and Xapian::Internal::PostList::next().

◆ recalc_maxweight()

double AndMaybePostList::recalc_maxweight ( )

virtual

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

The maximum weight that get_weight() can return can decrease as the match progresses (typically when the PostList tree prunes) - calling this method calculates a current upper bound.

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

Implements Xapian::Internal::PostList.

Definition at line 68 of file andmaybepostlist.cc.

◆ skip_to()

PostList * AndMaybePostList::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 115 of file andmaybepostlist.cc.

References Xapian::Internal::PostList::check(), Xapian::Internal::PostList::get_docid(), and Xapian::Internal::PostList::skip_to().

Member Data Documentation

◆ pl_did

Xapian::docid AndMaybePostList::pl_did = 0

private

Current docid from WrapperPostList's pl.

Definition at line 33 of file andmaybepostlist.h.

Referenced by maybe_matches().

◆ pl_max

double AndMaybePostList::pl_max

private

Current max weight from WrapperPostList's pl.

Definition at line 39 of file andmaybepostlist.h.

◆ pltree

PostListTree* AndMaybePostList::pltree

private

Definition at line 44 of file andmaybepostlist.h.

◆ r

PostList* AndMaybePostList::r

private

Right-hand side of OP_MAYBE.

Definition at line 30 of file andmaybepostlist.h.

Referenced by ~AndMaybePostList().

◆ r_did

Xapian::docid AndMaybePostList::r_did = 0

private

Current docid from r (or 0).

Definition at line 36 of file andmaybepostlist.h.

Referenced by maybe_matches().

◆ r_max

double AndMaybePostList::r_max

private

Current max weight from r.

Definition at line 42 of file andmaybepostlist.h.

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

matcher/andmaybepostlist.h
matcher/andmaybepostlist.cc

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ AndMaybePostList() [1/2]

◆ AndMaybePostList() [2/2]

◆ ~AndMaybePostList()

Member Function Documentation

◆ check()

◆ count_matching_subqs()

◆ decay_to_and()

◆ gather_position_lists()

◆ get_description()

◆ get_docid()

◆ get_wdf()

◆ get_weight()

◆ maybe_matches()

◆ next()

◆ recalc_maxweight()

◆ skip_to()

Member Data Documentation

◆ pl_did

◆ pl_max

◆ pltree

◆ r

◆ r_did

◆ r_max