A postlist comprising postlists from different databases merged together. More...

#include <mergepostlist.h>

Inheritance diagram for MergePostList:

Collaboration diagram for MergePostList:

Public Member Functions
Xapian::termcount	get_wdf () const
	Return the wdf for the document at the current position. More...

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...

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

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

const string *	get_sort_key () const

const string *	get_collapse_key () const
	If the collapse key is already known, return it. 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...

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

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...

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

	MergePostList (const std::vector< PostList > &plists_, MultiMatch matcher_, ValueStreamDocument &vsdoc_)

	~MergePostList ()

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 TermFreqs	get_termfreq_est_using_stats (const Xapian::Weight::Internal &stats) const
	Get an estimate for the termfreq and reltermfreq, given the stats. 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...

virtual Internal *	check (Xapian::docid did, double w_min, bool &valid)
	Check if the specified docid occurs in this 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...

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

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

Private Member Functions
	MergePostList (const MergePostList &)

MergePostList &	operator= (const MergePostList &)

Private Attributes
double	w_max

vector< PostList * >	plists

int	current

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

ValueStreamDocument &	vsdoc
	Document proxy used for valuestream caching. More...

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

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

Detailed Description

A postlist comprising postlists from different databases merged together.

Definition at line 35 of file mergepostlist.h.

Constructor & Destructor Documentation

◆ MergePostList() [1/2]

MergePostList::MergePostList ( const MergePostList & )

private

◆ MergePostList() [2/2]

MergePostList::MergePostList	(	const std::vector< PostList *> &	plists_,
		MultiMatch *	matcher_,
		ValueStreamDocument &	vsdoc_
	)

inline

Definition at line 93 of file mergepostlist.h.

References ~MergePostList().

◆ ~MergePostList()

MergePostList::~MergePostList ( )

Definition at line 38 of file mergepostlist.cc.

References LOGCALL_DTOR, and plists.

Referenced by MergePostList().

Member Function Documentation

◆ at_end()

bool MergePostList::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 179 of file mergepostlist.cc.

References Assert, current, LOGCALL, plists, and RETURN.

Referenced by next().

◆ count_matching_subqs()

Xapian::termcount MergePostList::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 214 of file mergepostlist.cc.

References current, LOGCALL, plists, and RETURN.

◆ get_collapse_key()

const string * MergePostList::get_collapse_key ( ) const

virtual

If the collapse key is already known, return it.

This is implemented by MSetPostList (and MergePostList). Other subclasses rely on the default implementation which just returns NULL.

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 151 of file mergepostlist.cc.

References Assert, current, LOGCALL, plists, and RETURN.

◆ get_description()

string MergePostList::get_description ( ) const

virtual

Return a string description of this object.

Implements Xapian::PostingIterator::Internal.

Definition at line 187 of file mergepostlist.cc.

References plists.

◆ get_docid()

Xapian::docid MergePostList::get_docid ( ) const

virtual

Return the current docid.

Implements Xapian::PostingIterator::Internal.

Definition at line 125 of file mergepostlist.cc.

References Assert, current, LOGCALL, plists, and RETURN.

◆ get_doclength()

Xapian::termcount MergePostList::get_doclength ( ) const

virtual

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

Implements Xapian::PostingIterator::Internal.

Definition at line 198 of file mergepostlist.cc.

References Assert, current, LOGCALL, plists, and RETURN.

◆ get_maxweight()

double MergePostList::get_maxweight ( ) const

virtual

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

Implements Xapian::PostingIterator::Internal.

Definition at line 159 of file mergepostlist.cc.

References LOGCALL, RETURN, and w_max.

◆ get_sort_key()

const string * MergePostList::get_sort_key ( ) const

virtual

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 143 of file mergepostlist.cc.

References Assert, current, LOGCALL, plists, and RETURN.

◆ get_termfreq_est()

Xapian::doccount MergePostList::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 112 of file mergepostlist.cc.

References LOGCALL, plists, and RETURN.

◆ get_termfreq_max()

Xapian::doccount MergePostList::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 86 of file mergepostlist.cc.

References LOGCALL, plists, and RETURN.

◆ get_termfreq_min()

Xapian::doccount MergePostList::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 99 of file mergepostlist.cc.

References LOGCALL, plists, and RETURN.

◆ get_unique_terms()

Xapian::termcount MergePostList::get_unique_terms ( ) const

virtual

Return the number of unique terms in the document.

Implements Xapian::PostingIterator::Internal.

Definition at line 206 of file mergepostlist.cc.

References Assert, current, LOGCALL, plists, and RETURN.

◆ get_wdf()

Xapian::termcount MergePostList::get_wdf ( ) const

virtual

Return the wdf for the document at the current position.

The default implementation throws Xapian::UnimplementedError.

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 79 of file mergepostlist.cc.

References current, LOGCALL, plists, and RETURN.

◆ get_weight()

double MergePostList::get_weight ( ) const

virtual

Return the weight contribution for the current position.

Implements Xapian::PostingIterator::Internal.

Definition at line 135 of file mergepostlist.cc.

References Assert, current, LOGCALL, plists, and RETURN.

◆ next()

PostList * MergePostList::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 48 of file mergepostlist.cc.

References at_end(), current, LOGCALL, LOGVALUE, matcher, ValueStreamDocument::new_subdb(), next_handling_prune(), plists, MultiMatch::recalc_maxweight(), RETURN, and vsdoc.

◆ operator=()

MergePostList& MergePostList::operator= ( const MergePostList & )

private

◆ recalc_maxweight()

double MergePostList::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 166 of file mergepostlist.cc.

References LOGCALL, plists, RETURN, and w_max.

◆ skip_to()

PostList * MergePostList::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 68 of file mergepostlist.cc.

References LOGCALL.

Member Data Documentation

◆ current

int MergePostList::current

private

Definition at line 45 of file mergepostlist.h.

Referenced by at_end(), count_matching_subqs(), get_collapse_key(), get_docid(), get_doclength(), get_sort_key(), get_unique_terms(), get_wdf(), get_weight(), and next().

◆ matcher

MultiMatch* MergePostList::matcher

private

The object which is using this postlist to perform a match.

This object needs to be notified when the tree changes such that the maximum weights need to be recalculated.

Definition at line 52 of file mergepostlist.h.

Referenced by next().

◆ plists

vector<PostList *> MergePostList::plists

private

Definition at line 43 of file mergepostlist.h.

Referenced by at_end(), count_matching_subqs(), get_collapse_key(), get_description(), get_docid(), get_doclength(), get_sort_key(), get_termfreq_est(), get_termfreq_max(), get_termfreq_min(), get_unique_terms(), get_wdf(), get_weight(), next(), recalc_maxweight(), and ~MergePostList().

◆ vsdoc

ValueStreamDocument& MergePostList::vsdoc

private

Document proxy used for valuestream caching.

We need to notify this when the subdatabase changes, as then the cached valuestreams need to be cleared as they will be for the wrong subdatabase.

Definition at line 60 of file mergepostlist.h.

Referenced by next().

◆ w_max

double MergePostList::w_max

private

Definition at line 41 of file mergepostlist.h.

Referenced by get_maxweight(), and recalc_maxweight().

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

matcher/mergepostlist.h
matcher/mergepostlist.cc

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ MergePostList() [1/2]

◆ MergePostList() [2/2]

◆ ~MergePostList()

Member Function Documentation

◆ at_end()

◆ count_matching_subqs()

◆ get_collapse_key()

◆ get_description()

◆ get_docid()

◆ get_doclength()

◆ get_maxweight()

◆ get_sort_key()

◆ get_termfreq_est()

◆ get_termfreq_max()

◆ get_termfreq_min()

◆ get_unique_terms()

◆ get_wdf()

◆ get_weight()

◆ next()

◆ operator=()

◆ recalc_maxweight()

◆ skip_to()

Member Data Documentation

◆ current

◆ matcher

◆ plists

◆ vsdoc

◆ w_max