PostList in a honey database. More...

#include <honey_postlist.h>

Inheritance diagram for HoneyPostList:

Collaboration diagram for HoneyPostList:

Public Member Functions
	HoneyPostList (const HoneyDatabase db_, std::string_view term_, HoneyCursor cursor_)
	Create HoneyPostList from already positioned cursor_. More...

	~HoneyPostList ()

bool	open_nearby_postlist (std::string_view term_, bool need_read_pos, LeafPostList *&pl) const
	Open another postlist from the same database. More...

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

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

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

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 (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...

Xapian::termcount	get_wdf_upper_bound () const

void	get_docid_range (Xapian::docid &first, Xapian::docid &last) const
	Get the bounds on the range of docids this PostList can return. More...

std::string	get_description () const
	Return a string description of this object. More...

Public Member Functions inherited from LeafPostList
	~LeafPostList ()

Xapian::termcount	get_collfreq () const
	Get the collection frequency of the term. More...

void	set_termweight (const Xapian::Weight *weight_)
	Set the weighting scheme to use during matching. More...

double	resolve_lazy_termweight (Xapian::Weight weight_, Xapian::Weight::Internal stats, Xapian::termcount qlen, Xapian::termcount wqf, double factor, const Xapian::Database::Internal *shard)

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...

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...

const std::string &	get_term () const
	Get the term name. More...

void	set_term (std::string_view term_)
	Set the term name. 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 *	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 PostList *	check (Xapian::docid did, double w_min, bool &valid)
	Check if the specified docid occurs in this 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...

Private Member Functions
HoneyPostList &	operator= (const HoneyPostList &)=delete
	Don't allow assignment. More...

	HoneyPostList (const HoneyPostList &)=delete
	Don't allow copying. More...

bool	update_reader ()
	Update reader to use the chunk currently pointed to by cursor. More...

Private Attributes
HoneyCursor *	cursor
	Cursor on the postlist table. More...

Honey::PostingChunkReader	reader

Xapian::docid	last_did
	The highest document id in this posting list. More...

const HoneyDatabase *	db
	HoneyDatabase to get position table object from. More...

Xapian::termcount	wdf_max
	Maximum wdf for this postlist. More...

bool	started = false
	Needed so that first next() does nothing. More...

Additional Inherited Members
Protected Member Functions inherited from LeafPostList
	LeafPostList (std::string_view term_)
	Only constructable as a base class for derived classes. More...

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

Protected Attributes inherited from LeafPostList
const Xapian::Weight *	weight = nullptr

std::string	term
	The term name for this postlist (empty for an alldocs postlist). More...

Xapian::termcount	collfreq
	The collection frequency of the term. More...

Protected Attributes inherited from Xapian::Internal::PostList
Xapian::doccount	termfreq
	Estimate of the number of documents this PostList will return. More...

Detailed Description

PostList in a honey database.

Definition at line 153 of file honey_postlist.h.

Constructor & Destructor Documentation

◆ HoneyPostList() [1/2]

HoneyPostList::HoneyPostList ( const HoneyPostList & )

privatedelete

Don't allow copying.

Referenced by open_nearby_postlist().

◆ HoneyPostList() [2/2]

HoneyPostList::HoneyPostList	(	const HoneyDatabase *	db_,
		std::string_view	term_,
		HoneyCursor *	cursor_
	)

Create HoneyPostList from already positioned cursor_.

Definition at line 53 of file honey_postlist.cc.

References Assert, Honey::PostingChunkReader::assign(), LeafPostList::collfreq, HoneyCursor::current_tag, cursor, decode_initial_chunk_header(), Honey::PostingChunkReader::init(), last_did, mul_overflows(), p, HoneyCursor::read_tag(), reader, Xapian::Internal::PostList::termfreq, TOP_BIT_SET, and wdf_max.

◆ ~HoneyPostList()

HoneyPostList::~HoneyPostList ( )

Definition at line 117 of file honey_postlist.cc.

References cursor.

Member Function Documentation

◆ at_end()

bool HoneyPostList::at_end ( ) const

virtual

Return true if the current position is past the last entry in this list.

Implements Xapian::Internal::PostList.

Definition at line 158 of file honey_postlist.cc.

References cursor.

◆ get_description()

string HoneyPostList::get_description ( ) const

virtual

Return a string description of this object.

Implements Xapian::Internal::PostList.

Reimplemented in HoneyPosPostList.

Definition at line 264 of file honey_postlist.cc.

References LeafPostList::term.

◆ get_docid()

Xapian::docid HoneyPostList::get_docid ( ) const

virtual

Return the current docid.

Implements Xapian::Internal::PostList.

Definition at line 146 of file honey_postlist.cc.

References Honey::PostingChunkReader::get_docid(), and reader.

Referenced by open_position_list(), and HoneyPosPostList::read_position_list().

◆ get_docid_range()

void HoneyPostList::get_docid_range	(	Xapian::docid &	first,
		Xapian::docid &	last
	)		const

virtual

Get the bounds on the range of docids this PostList can return.

Parameters

[out]	first	Set to a lower bound on the docids that can be returned, or not changed if there's no known lower bound (other than 1).
[out]	last	Set to an upper bound on the docids that can be returned, or not changed if there's no known upper bound (other than the highest used docid).

The default implementation (PostList::get_docid_range()) does nothing, which is suitable when there's no known lower or upper bound.

Reimplemented from Xapian::Internal::PostList.

Definition at line 251 of file honey_postlist.cc.

References Assert, AssertRel, Honey::PostingChunkReader::get_docid(), last_did, reader, started, and Xapian::Internal::PostList::termfreq.

◆ get_wdf()

Xapian::termcount HoneyPostList::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 152 of file honey_postlist.cc.

References Honey::PostingChunkReader::get_wdf(), and reader.

◆ get_wdf_upper_bound()

Xapian::termcount HoneyPostList::get_wdf_upper_bound ( ) const

virtual

Implements LeafPostList.

Definition at line 245 of file honey_postlist.cc.

References wdf_max.

◆ next()

PostList * HoneyPostList::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 170 of file honey_postlist.cc.

References Assert, Honey::PostingChunkReader::at_end(), cursor, Honey::PostingChunkReader::get_docid(), last_did, HoneyCursor::next(), Honey::PostingChunkReader::next(), rare, reader, started, and update_reader().

◆ open_nearby_postlist()

bool HoneyPostList::open_nearby_postlist	(	std::string_view	term_,
		bool	need_read_pos,
		LeafPostList *&	pl
	)		const

virtual

Open another postlist from the same database.

Parameters

	term_	The term to open a postlist for (must not be an empty string). If term_ is near to this postlist's term, then this can be a lot more efficient (and if it isn't very near, there's not much of a penalty). Using this method can make a wildcard expansion much more memory efficient.
	need_read_pos	Does the postlist need to support read_position_list()? Note that open_position_list() may still be called even if need_read_pos is false.
[out]	pl	If true is returned, set to a new LeafPostList object (or may be set to NULL if the term doesn't index any documents). The caller takes ownership of the returned object.

Returns: true if successful (and pl has been set); false if not (in which case the caller should probably open the postlist via the database instead).

Reimplemented from LeafPostList.

Definition at line 123 of file honey_postlist.cc.

References Assert, cursor, db, HoneyPostList(), and Honey::make_postingchunk_key().

◆ open_position_list()

PositionList * HoneyPostList::open_position_list ( ) const

virtual

Read the position list for the term in the current document and return a pointer to it (not owned by the PostList).

The default implementation throws Xapian::UnimplementedError.

Reimplemented from Xapian::Internal::PostList.

Definition at line 164 of file honey_postlist.cc.

References db, get_docid(), HoneyPositionTable::open_position_list(), HoneyDatabase::position_table, and LeafPostList::term.

◆ operator=()

HoneyPostList& HoneyPostList::operator= ( const HoneyPostList & )

privatedelete

Don't allow assignment.

◆ skip_to()

PostList * HoneyPostList::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 200 of file honey_postlist.cc.

References HoneyCursor::after_end(), Assert, Honey::PostingChunkReader::at_end(), cursor, HoneyCursor::find_entry_ge(), last_did, Honey::make_postingchunk_key(), rare, reader, Honey::PostingChunkReader::skip_to(), started, LeafPostList::term, and update_reader().