LeafPostList Class Reference

Abstract base class for leaf postlists. More...

#include <leafpostlist.h>

Inheritance diagram for LeafPostList:

Collaboration diagram for LeafPostList:

List of all members.

Public Member Functions

~LeafPostList ()

void set_termweight (const Xapian::Weight *weight_)

Set the weighting scheme to use during matching.

virtual Xapian::doccount get_termfreq () const =0

Return the exact term frequency.

Xapian::doccount get_termfreq_min () const

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

Xapian::doccount get_termfreq_max () const

Get an upper 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::weight get_maxweight () const

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

Xapian::weight get_weight () const

Return the weight contribution for the current position.

Xapian::weight recalc_maxweight ()

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

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

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

Xapian::termcount count_matching_subqs () const

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

Protected Member Functions

LeafPostList (const std::string &term_)

Only constructable as a base class for derived classes.

Protected Attributes

const Xapian::Weight * weight

bool need_doclength

std::string term

The term name for this postlist (empty for an alldocs postlist).

Private Member Functions

void operator= (const LeafPostList &)

Don't allow assignment.

LeafPostList (const LeafPostList &)

Don't allow copying.

Detailed Description

Abstract base class for leaf postlists.

This class provides the following features in addition to the PostList class:

Definition at line 38 of file leafpostlist.h.

Constructor & Destructor Documentation

LeafPostList::LeafPostList ( const LeafPostList & ) [private]

Don't allow copying.

LeafPostList::LeafPostList ( const std::string & term_ ) [inline, protected]

Only constructable as a base class for derived classes.

Definition at line 54 of file leafpostlist.h.

LeafPostList::~LeafPostList ( )

Definition at line 32 of file leafpostlist.cc.

References weight.

Member Function Documentation

Xapian::termcount LeafPostList::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 101 of file leafpostlist.cc.

References weight.

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

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

Implements Xapian::PostingIterator::Internal.

Definition at line 65 of file leafpostlist.cc.

References Xapian::Weight::get_maxpart(), and weight.

Referenced by recalc_maxweight().

virtual Xapian::doccount LeafPostList::get_termfreq ( ) const [pure virtual]

Return the exact term frequency.

Leaf postlists have an exact termfreq, which get_termfreq_min(), get_termfreq_max(), and get_termfreq_est() all report.

Implemented in BrassAllDocsPostList, BrassPostList, ChertAllDocsPostList, ChertModifiedPostList, ChertPostList, FlintAllDocsPostList, FlintModifiedPostList, FlintPostList, InMemoryPostList, InMemoryAllDocsPostList, NetworkPostList, and ContiguousAllDocsPostList.

Referenced by get_termfreq_est(), get_termfreq_max(), and get_termfreq_min().

Xapian::doccount LeafPostList::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 50 of file leafpostlist.cc.

References get_termfreq().

TermFreqs LeafPostList::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 88 of file leafpostlist.cc.

References Assert, Xapian::Weight::Internal::collection_size, LOGCALL, RETURN, Xapian::Weight::Internal::rset_size, term, and Xapian::Weight::Internal::termfreqs.

Xapian::doccount LeafPostList::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 44 of file leafpostlist.cc.

References get_termfreq().

Xapian::doccount LeafPostList::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 38 of file leafpostlist.cc.

References get_termfreq().

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

Return the weight contribution for the current position.

Implements Xapian::PostingIterator::Internal.

Definition at line 71 of file leafpostlist.cc.

References Xapian::PostingIterator::Internal::get_doclength(), Xapian::Weight::get_sumpart(), Xapian::PostingIterator::Internal::get_wdf(), need_doclength, and weight.

void LeafPostList::operator= ( const LeafPostList & ) [private]

Don't allow assignment.

Xapian::weight LeafPostList::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 82 of file leafpostlist.cc.

References get_maxweight().

void LeafPostList::set_termweight ( const Xapian::Weight * weight_ )

Set the weighting scheme to use during matching.

If this isn't called, get_weight() and get_maxweight() will both return 0.

You should not call this more than once on a particular object.

Parameters:

weight_

The weighting object to use. Must not be NULL.

Definition at line 56 of file leafpostlist.cc.

References Assert, Xapian::Weight::get_sumpart_needs_doclength_(), need_doclength, and weight.

Referenced by LocalSubMatch::postlist_from_op_leaf_query().

Member Data Documentation

bool LeafPostList::need_doclength [protected]

Definition at line 48 of file leafpostlist.h.

Referenced by get_weight(), and set_termweight().

std::string LeafPostList::term [protected]

The term name for this postlist (empty for an alldocs postlist).

Definition at line 51 of file leafpostlist.h.

Referenced by BrassPostList::BrassPostList(), ChertPostList::ChertPostList(), FlintPostList::FlintPostList(), NetworkPostList::get_description(), FlintPostList::get_description(), ChertPostList::get_description(), BrassPostList::get_description(), FlintModifiedPostList::get_termfreq(), ChertModifiedPostList::get_termfreq(), get_termfreq_est_using_stats(), FlintPostList::move_to_chunk_containing(), ChertPostList::move_to_chunk_containing(), BrassPostList::move_to_chunk_containing(), NetworkPostList::NetworkPostList(), FlintPostList::next_chunk(), ChertPostList::next_chunk(), BrassPostList::next_chunk(), NetworkPostList::open_position_list(), FlintPostList::open_position_list(), FlintModifiedPostList::open_position_list(), ChertPostList::open_position_list(), ChertModifiedPostList::open_position_list(), BrassPostList::open_position_list(), NetworkPostList::read_position_list(), FlintPostList::read_position_list(), FlintModifiedPostList::read_position_list(), ChertPostList::read_position_list(), ChertModifiedPostList::read_position_list(), and BrassPostList::read_position_list().

const Xapian::Weight* LeafPostList::weight [protected]

Definition at line 46 of file leafpostlist.h.

Referenced by count_matching_subqs(), get_maxweight(), get_weight(), set_termweight(), and ~LeafPostList().

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

common/leafpostlist.h
api/leafpostlist.cc


Public Member Functions
	~LeafPostList ()
void	set_termweight (const Xapian::Weight *weight_)
	Set the weighting scheme to use during matching.
virtual Xapian::doccount	get_termfreq () const =0
	Return the exact term frequency.
Xapian::doccount	get_termfreq_min () const
	Get a lower bound on the number of documents indexed by this term.
Xapian::doccount	get_termfreq_max () const
	Get an upper 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::weight	get_maxweight () const
	Return an upper bound on what get_weight() can return.
Xapian::weight	get_weight () const
	Return the weight contribution for the current position.
Xapian::weight	recalc_maxweight ()
	Recalculate the upper bound on what get_weight() can return.
TermFreqs	get_termfreq_est_using_stats (const Xapian::Weight::Internal &stats) const
	Get an estimate for the termfreq and reltermfreq, given the stats.
Xapian::termcount	count_matching_subqs () const
	Count the number of leaf subqueries which match at the current position.
Protected Member Functions
	LeafPostList (const std::string &term_)
	Only constructable as a base class for derived classes.
Protected Attributes
const Xapian::Weight *	weight
bool	need_doclength
std::string	term
	The term name for this postlist (empty for an alldocs postlist).
Private Member Functions
void	operator= (const LeafPostList &)
	Don't allow assignment.
	LeafPostList (const LeafPostList &)
	Don't allow copying.