A TermList in a chert database. More...

#include <chert_termlist.h>

Inheritance diagram for ChertTermList:

Collaboration diagram for ChertTermList:

Public Member Functions
	ChertTermList (Xapian::Internal::intrusive_ptr< const ChertDatabase > db_, Xapian::docid did_)
	Create a new ChertTermList object for document did_ in DB db_. More...

chert_doclen_t	get_doclength () const
	Return the length of this document. More...

Xapian::termcount	get_approx_size () const
	Return approximate size of this termlist. More...

void	accumulate_stats (Xapian::Internal::ExpandStats &stats) const
	Collate weighting information for the current term. More...

std::string	get_termname () const
	Return the termname at the current position. More...

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

Xapian::doccount	get_termfreq () const
	Return the term frequency for the term at the current position. More...

TermList *	next ()
	Advance the current position to the next term in the termlist. More...

TermList *	skip_to (const std::string &term)
	Skip forward to the specified term. More...

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

Xapian::termcount	positionlist_count () const
	Return the length of the position list for the current position. More...

Xapian::PositionIterator	positionlist_begin () const
	Return a PositionIterator for the current position. More...

Public Member Functions inherited from Xapian::TermIterator::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 const std::vector< Xapian::termpos > *	get_vector_termpos () const
	Get pointer to vector<termpos> if that's the internal representation. More...

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

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

	ChertTermList (const ChertTermList &)
	Don't allow copying. More...

Private Attributes
Xapian::Internal::intrusive_ptr< const ChertDatabase >	db
	The database we're reading data from. More...

Xapian::docid	did
	The document id that this TermList is for. More...

chert_doclen_t	doclen
	The length of document did. More...

Xapian::termcount	termlist_size
	The number of entries in this termlist. More...

std::string	data
	The tag value from the termlist table which holds the encoded termlist. More...

const char *	pos
	Current position with the encoded tag value held in data. More...

const char *	end
	Pointer to the end of the encoded tag value. More...

std::string	current_term
	The termname at the current position. More...

Xapian::termcount	current_wdf
	The wdf for the term at the current position. More...

Xapian::doccount	current_termfreq
	The term frequency for the term at the current position. More...

Additional Inherited Members
Public Attributes inherited from Xapian::TermIterator::Internal
size_t	shard_index = 0
	Which shard of a multidatabase this is from. More...

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

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

Detailed Description

A TermList in a chert database.

Definition at line 41 of file chert_termlist.h.

Constructor & Destructor Documentation

◆ ChertTermList() [1/2]

ChertTermList::ChertTermList ( const ChertTermList & )

private

Don't allow copying.

◆ ChertTermList() [2/2]

ChertTermList::ChertTermList	(	Xapian::Internal::intrusive_ptr< const ChertDatabase >	db_,
		Xapian::docid	did_
	)

Create a new ChertTermList object for document did_ in DB db_.

Definition at line 38 of file chert_termlist.cc.

References data, db, did, doclen, end, ChertTable::get_exact_entry(), LOGCALL_CTOR, ChertTermListTable::make_key(), pos, Xapian::Internal::str(), termlist_size, ChertDatabase::termlist_table, and unpack_uint().

Member Function Documentation

◆ accumulate_stats()

void ChertTermList::accumulate_stats ( Xapian::Internal::ExpandStats & stats ) const

virtual

Collate weighting information for the current term.

Reimplemented from Xapian::TermIterator::Internal.

Definition at line 95 of file chert_termlist.cc.

References Xapian::Internal::ExpandStats::accumulate(), Assert, at_end(), current_wdf, db, doclen, ChertDatabase::get_doccount(), get_termfreq(), LOGCALL_VOID, and Xapian::TermIterator::Internal::shard_index.

◆ at_end()

bool ChertTermList::at_end ( ) const

virtual

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

Implements Xapian::TermIterator::Internal.

Definition at line 183 of file chert_termlist.cc.

References LOGCALL, pos, and RETURN.

Referenced by accumulate_stats(), ChertWritableDatabase::delete_document(), next(), and ChertWritableDatabase::replace_document().

◆ get_approx_size()

Xapian::termcount ChertTermList::get_approx_size ( ) const

virtual

Return approximate size of this termlist.

For a ChertTermList, this value will always be exact.

Implements Xapian::TermIterator::Internal.

Definition at line 88 of file chert_termlist.cc.

References LOGCALL, RETURN, and termlist_size.

Referenced by ChertDatabase::get_unique_terms(), and ChertWritableDatabase::get_unique_terms().

◆ get_doclength()

chert_doclen_t ChertTermList::get_doclength ( ) const

Return the length of this document.

This is a non-virtual method, used by ChertDatabase.

Definition at line 81 of file chert_termlist.cc.

References doclen, LOGCALL, and RETURN.

Referenced by ChertWritableDatabase::delete_document(), and ChertWritableDatabase::replace_document().

◆ get_termfreq()

Xapian::doccount ChertTermList::get_termfreq ( ) const

virtual

Return the term frequency for the term at the current position.

In order to be able to support updating databases efficiently, we can't store this value in the termlist table, so it has to be read from the postlist table, which is relatively expensive (compared to reading the wdf for example).

Implements Xapian::TermIterator::Internal.

Definition at line 118 of file chert_termlist.cc.

References current_term, current_termfreq, db, ChertDatabase::get_freqs(), LOGCALL, and RETURN.

Referenced by accumulate_stats().