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:

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Collaboration diagram for AndNotPostList:

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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.

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

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

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::termcount 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)

Xapian::termcount get_wdf () const

get_wdf() for ANDNOT postlists returns the wdf of the left hand side.

Xapian::termcount count_matching_subqs () const

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

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 34 of file andnotpostlist.h.

Constructor & Destructor Documentation

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

Definition at line 61 of file andnotpostlist.cc.

References LOGCALL_CTOR.

Member Function Documentation

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

Definition at line 31 of file andnotpostlist.cc.

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

Referenced by next(), 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 192 of file andnotpostlist.cc.

References lhead, LOGCALL, and RETURN.

Xapian::termcount AndNotPostList::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 219 of file andnotpostlist.cc.

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

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

Return a string description of this object.

Implements Xapian::PostingIterator::Internal.

Definition at line 199 of file andnotpostlist.cc.

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

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

Return the current docid.

Implements Xapian::PostingIterator::Internal.

Definition at line 160 of file andnotpostlist.cc.

References lhead, LOGCALL, and RETURN.

Xapian::termcount AndNotPostList::get_doclength ( ) const [virtual]

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

Implements Xapian::PostingIterator::Internal.

Definition at line 205 of file andnotpostlist.cc.

References Xapian::PostingIterator::Internal::get_doclength(), BranchPostList::l, LOGCALL, 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 176 of file andnotpostlist.cc.

References Xapian::PostingIterator::Internal::get_maxweight(), BranchPostList::l, LOGCALL, 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 118 of file andnotpostlist.cc.

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

TermFreqs AndNotPostList::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 130 of file andnotpostlist.cc.

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

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 99 of file andnotpostlist.cc.

References Xapian::PostingIterator::Internal::get_termfreq_max(), BranchPostList::l, LOGCALL, 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 107 of file andnotpostlist.cc.

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

Xapian::termcount AndNotPostList::get_wdf ( ) const [virtual]

get_wdf() for ANDNOT postlists returns the wdf of the left hand side.

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 212 of file andnotpostlist.cc.

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

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

Return the weight contribution for the current position.

Implements Xapian::PostingIterator::Internal.

Definition at line 168 of file andnotpostlist.cc.

References Xapian::PostingIterator::Internal::get_weight(), BranchPostList::l, LOGCALL, 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 72 of file andnotpostlist.cc.

References advance_to_next_match(), BranchPostList::l, LOGCALL, Xapian::PostingIterator::Internal::next(), 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.

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 183 of file andnotpostlist.cc.

References BranchPostList::l, LOGCALL, Xapian::PostingIterator::Internal::recalc_maxweight(), 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 91 of file andnotpostlist.cc.

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

Referenced by sync_and_skip_to().

PostList * AndNotPostList::sync_and_skip_to	(	Xapian::docid	id,
		Xapian::weight	w_min,
		Xapian::docid	lh,
		Xapian::docid	rh
	)

Definition at line 79 of file andnotpostlist.cc.

References lhead, LOGCALL, RETURN, rhead, and skip_to().

Member Data Documentation

Xapian::doccount AndNotPostList::dbsize [private]

Number of documents in the database this postlist is across.

Definition at line 39 of file andnotpostlist.h.

Referenced by get_termfreq_est().

Xapian::docid AndNotPostList::lhead [private]

Definition at line 36 of file andnotpostlist.h.

Referenced by advance_to_next_match(), at_end(), get_docid(), skip_to(), and sync_and_skip_to().

Xapian::docid AndNotPostList::rhead [private]

Definition at line 36 of file andnotpostlist.h.

Referenced by advance_to_next_match(), and sync_and_skip_to().

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

matcher/andnotpostlist.h
matcher/andnotpostlist.cc


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.
TermFreqs	get_termfreq_est_using_stats (const Xapian::Weight::Internal &stats) const
	Get an estimate for the termfreq and reltermfreq, given the stats.
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::termcount	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)
Xapian::termcount	get_wdf () const
	get_wdf() for ANDNOT postlists returns the wdf of the left hand side.
Xapian::termcount	count_matching_subqs () const
	Count the number of leaf subqueries which match at the current position.
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.