AndNotPostList Class Reference

A postlist generated by taking one postlist (the left-hand postlist), and removing any documents which are in the other (right-hand) postlist. More...

#include <andnotpostlist.h>

Inheritance diagram for AndNotPostList:

[legend]Collaboration diagram for AndNotPostList:

[legend]List of all members.


Public Member Functions
Xapian::doccount	get_termfreq_max () const
	Get an upper bound on the number of documents indexed by this term.
Xapian::doccount	get_termfreq_min () const
	Get a lower bound on the number of documents indexed by this term.
Xapian::doccount	get_termfreq_est () const
	Get an estimate of the number of documents indexed by this term.
Xapian::docid	get_docid () const
	Return the current docid.
Xapian::weight	get_weight () const
	Return the weight contribution for the current position.
Xapian::weight	get_maxweight () const
	Return an upper bound on what get_weight() can return.
Xapian::weight	recalc_maxweight ()
	Recalculate the upper bound on what get_weight() can return.
PostList *	next (Xapian::weight w_min)
	Advance the current position to the next document in the postlist.
PostList *	skip_to (Xapian::docid did, Xapian::weight w_min)
	Skip forward to the specified docid.
bool	at_end () const
	Return true if the current position is past the last entry in this list.
std::string	get_description () const
	Return a string description of this object.
virtual Xapian::doclength	get_doclength () const
	Return the document length of the document the current term comes from.
	AndNotPostList (PostList left, PostList right, MultiMatch *matcher_, Xapian::doccount dbsize_)
PostList *	sync_and_skip_to (Xapian::docid id, Xapian::weight w_min, Xapian::docid lh, Xapian::docid rh)
Private Member Functions
PostList *	advance_to_next_match (Xapian::weight w_min, PostList *ret)
Private Attributes
Xapian::docid	lhead
Xapian::docid	rhead
Xapian::doccount	dbsize
	Number of documents in the database this postlist is across.

Detailed Description

A postlist generated by taking one postlist (the left-hand postlist), and removing any documents which are in the other (right-hand) postlist.

The weight for a posting is the weight in the left-hand postlist.

Definition at line 35 of file andnotpostlist.h.

Constructor & Destructor Documentation

AndNotPostList::AndNotPostList	(	PostList *	left,
		PostList *	right,
		MultiMatch *	matcher_,
		Xapian::doccount	dbsize_
	)

Definition at line 59 of file andnotpostlist.cc.

References DEBUGCALL.

Member Function Documentation

PostList * AndNotPostList::advance_to_next_match	(	Xapian::weight	w_min,
		PostList *	ret
	)			`[private]`

Definition at line 29 of file andnotpostlist.cc.

References Xapian::PostingIterator::Internal::at_end(), DEBUGCALL, Xapian::PostingIterator::Internal::get_docid(), BranchPostList::handle_prune(), BranchPostList::l, lhead, BranchPostList::matcher, next_handling_prune(), BranchPostList::r, RETURN, rhead, and skip_to_handling_prune().

Referenced by next(), and skip_to().

Xapian::doccount AndNotPostList::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 97 of file andnotpostlist.cc.

References DEBUGCALL, Xapian::PostingIterator::Internal::get_termfreq_max(), BranchPostList::l, and RETURN.

Xapian::doccount AndNotPostList::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 105 of file andnotpostlist.cc.

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

Xapian::doccount AndNotPostList::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 116 of file andnotpostlist.cc.

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

Xapian::docid AndNotPostList::get_docid ( ) const [virtual]

Return the current docid.

Implements Xapian::PostingIterator::Internal.

Definition at line 128 of file andnotpostlist.cc.

References DEBUGCALL, lhead, and RETURN.

Xapian::weight AndNotPostList::get_weight ( ) const [virtual]

Return the weight contribution for the current position.

Implements Xapian::PostingIterator::Internal.

Definition at line 136 of file andnotpostlist.cc.

References DEBUGCALL, Xapian::PostingIterator::Internal::get_weight(), BranchPostList::l, and RETURN.

Xapian::weight AndNotPostList::get_maxweight ( ) const [virtual]

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

Implements Xapian::PostingIterator::Internal.

Definition at line 144 of file andnotpostlist.cc.

References DEBUGCALL, Xapian::PostingIterator::Internal::get_maxweight(), BranchPostList::l, and RETURN.

Xapian::weight AndNotPostList::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.

Implements Xapian::PostingIterator::Internal.

Definition at line 151 of file andnotpostlist.cc.

References DEBUGCALL, BranchPostList::l, Xapian::PostingIterator::Internal::recalc_maxweight(), and RETURN.

PostList * AndNotPostList::next ( Xapian::weight 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() 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 70 of file andnotpostlist.cc.

References advance_to_next_match(), DEBUGCALL, BranchPostList::l, Xapian::PostingIterator::Internal::next(), and RETURN.

PostList * AndNotPostList::skip_to	(	Xapian::docid	,
		Xapian::weight	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 89 of file andnotpostlist.cc.

References advance_to_next_match(), DEBUGCALL, BranchPostList::l, lhead, RETURN, and Xapian::PostingIterator::Internal::skip_to().

Referenced by sync_and_skip_to().

bool AndNotPostList::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 158 of file andnotpostlist.cc.

References DEBUGCALL, lhead, and RETURN.

std::string AndNotPostList::get_description ( ) const [virtual]

Return a string description of this object.

Implements Xapian::PostingIterator::Internal.