A TermList in a glass database. More...

#include <glass_termlist.h>

Inheritance diagram for GlassTermList:

Collaboration diagram for GlassTermList:

Public Member Functions
	GlassTermList (Xapian::Internal::intrusive_ptr< const GlassDatabase > db_, Xapian::docid did_, bool throw_if_not_present=true)
	Create a new GlassTermList object for document did_ in DB db_. More...

bool	not_present () const
	Check if the term isn't present. More...

Xapian::termcount	get_doclength () const
	Return the length of this document. More...

Xapian::termcount	get_unique_terms () const
	Return the number of unique terms. 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...

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 (std::string_view term)
	Skip forward to the specified term. More...

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

PositionList *	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...

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

virtual const Xapian::VecCOW< Xapian::termpos > *	get_vec_termpos () const
	Get pointer to VecCOW<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 GlassTermList &)
	Don't allow assignment. More...

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

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

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

Xapian::termcount	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...

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...

Protected Attributes inherited from Xapian::TermIterator::Internal
std::string	current_term
	The current term. More...

Detailed Description

A TermList in a glass database.

Definition at line 41 of file glass_termlist.h.

Constructor & Destructor Documentation

◆ GlassTermList() [1/2]

GlassTermList::GlassTermList ( const GlassTermList & )

private

Don't allow copying.

◆ GlassTermList() [2/2]

GlassTermList::GlassTermList	(	Xapian::Internal::intrusive_ptr< const GlassDatabase >	db_,
		Xapian::docid	did_,
		bool	throw_if_not_present = `true`
	)

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

Parameters

throw_if_not_present Specifies behaviour if document did_ isn't present: if true then throw DocNotFoundError, otherwise the constructed GlassTermList object will signal at_end() before next() is called (normally at_end() isn't meaningful on a freshly constructed TermList).

Definition at line 38 of file glass_termlist.cc.

References data, db, did, doclen, end, GlassTable::get_exact_entry(), LOGCALL_CTOR, GlassTermListTable::make_key(), pos, Xapian::Internal::str(), termlist_size, GlassDatabase::termlist_table, and unpack_uint().

Member Function Documentation

◆ accumulate_stats()

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

virtual

Collate weighting information for the current term.

Reimplemented from Xapian::TermIterator::Internal.

Definition at line 111 of file glass_termlist.cc.

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

◆ get_approx_size()

Xapian::termcount GlassTermList::get_approx_size ( ) const

virtual

Return approximate size of this termlist.

For a GlassTermList, this value will always be exact.

Implements Xapian::TermIterator::Internal.

Definition at line 104 of file glass_termlist.cc.

References LOGCALL, RETURN, and termlist_size.

Referenced by GlassWritableDatabase::get_unique_terms().

◆ get_doclength()

Xapian::termcount GlassTermList::get_doclength ( ) const

Return the length of this document.

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

Definition at line 87 of file glass_termlist.cc.

References doclen, LOGCALL, and RETURN.

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

◆ get_termfreq()

Xapian::doccount GlassTermList::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 127 of file glass_termlist.cc.

References Xapian::TermIterator::Internal::current_term, current_termfreq, db, GlassDatabase::get_freqs(), LOGCALL, and RETURN.

Referenced by accumulate_stats().

◆ get_unique_terms()

Xapian::termcount GlassTermList::get_unique_terms ( ) const

Return the number of unique terms.

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

Definition at line 94 of file glass_termlist.cc.

References doclen, LOGCALL, RETURN, and termlist_size.

◆ get_wdf()

Xapian::termcount GlassTermList::get_wdf ( ) const

virtual

Return the wdf for the term at the current position.

Implements Xapian::TermIterator::Internal.

Definition at line 120 of file glass_termlist.cc.

References current_wdf, LOGCALL, and RETURN.

Referenced by GlassWritableDatabase::delete_document(), GlassDatabase::get_wdfdocmax(), and GlassWritableDatabase::replace_document().

◆ next()

TermList * GlassTermList::next ( )

virtual

Advance the current position to the next term in the termlist.

The list starts before the first term in the list, so next(), skip_to() or check() must be called before any methods which need the context of the current position.

Returns: Always returns 0 for a GlassTermList.

Implements Xapian::TermIterator::Internal.

Definition at line 136 of file glass_termlist.cc.

References Assert, Xapian::TermIterator::Internal::current_term, current_termfreq, current_wdf, end, LOGCALL, pos, RETURN, and unpack_uint().

Referenced by GlassWritableDatabase::delete_document(), GlassDatabase::get_wdfdocmax(), GlassWritableDatabase::replace_document(), and skip_to().

◆ not_present()

bool GlassTermList::not_present ( ) const

inline

Check if the term isn't present.

If you call the constructor with throw_if_not_present=false then you need to call this method to check if the term is present before you call other methods.

Definition at line 102 of file glass_termlist.h.

References pos.

Referenced by GlassWritableDatabase::replace_document().

◆ operator=()

void GlassTermList::operator= ( const GlassTermList & )

private

Don't allow assignment.

◆ positionlist_begin()

PositionList * GlassTermList::positionlist_begin ( ) const

virtual

Return a PositionIterator for the current position.

Implements Xapian::TermIterator::Internal.

Definition at line 199 of file glass_termlist.cc.

References Xapian::TermIterator::Internal::current_term, db, did, LOGCALL, GlassDatabase::open_position_list(), and RETURN.

◆ positionlist_count()

Xapian::termcount GlassTermList::positionlist_count ( ) const

virtual

Return the length of the position list for the current position.

Implements Xapian::TermIterator::Internal.

Definition at line 192 of file glass_termlist.cc.

References Xapian::TermIterator::Internal::current_term, db, did, LOGCALL, GlassDatabase::positionlist_count(), and RETURN.

◆ skip_to()

TermList * GlassTermList::skip_to ( std::string_view term )

virtual

Skip forward to the specified term.

If the specified term isn't in the list, position ourselves on the first term after term.

Returns: Normally returns NULL to indicate success. If no terms after term exist, returns this; if another 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::TermIterator::Internal.

Definition at line 181 of file glass_termlist.cc.

References Xapian::TermIterator::Internal::current_term, LOGCALL, next(), RETURN, and term.

Member Data Documentation

◆ current_termfreq

Xapian::doccount GlassTermList::current_termfreq

mutableprivate

The term frequency for the term at the current position.

This will have the value 0 if the term frequency has not yet been looked up in the database (so it needs to be mutable).

Definition at line 80 of file glass_termlist.h.

Referenced by get_termfreq(), and next().

◆ current_wdf

Xapian::termcount GlassTermList::current_wdf

private

The wdf for the term at the current position.

Definition at line 73 of file glass_termlist.h.

Referenced by accumulate_stats(), get_wdf(), and next().

◆ data

std::string GlassTermList::data

private

The tag value from the termlist table which holds the encoded termlist.

Definition at line 61 of file glass_termlist.h.

Referenced by GlassTermList().

◆ db

Xapian::Internal::intrusive_ptr<const GlassDatabase> GlassTermList::db

private

The database we're reading data from.

Definition at line 49 of file glass_termlist.h.

Referenced by accumulate_stats(), get_termfreq(), GlassTermList(), positionlist_begin(), and positionlist_count().

◆ did

Xapian::docid GlassTermList::did

private

The document id that this TermList is for.

Definition at line 52 of file glass_termlist.h.

Referenced by GlassTermList(), positionlist_begin(), and positionlist_count().

◆ doclen

Xapian::termcount GlassTermList::doclen

private

The length of document did.

Definition at line 55 of file glass_termlist.h.

Referenced by accumulate_stats(), get_doclength(), get_unique_terms(), and GlassTermList().

◆ end

const char* GlassTermList::end

private

Pointer to the end of the encoded tag value.

Definition at line 70 of file glass_termlist.h.

Referenced by GlassTermList(), and next().

◆ pos

const char* GlassTermList::pos

private

Current position with the encoded tag value held in data.

If we've iterated to the end of the list, this gets set to NULL.

Definition at line 67 of file glass_termlist.h.

Referenced by accumulate_stats(), GlassTermList(), next(), and not_present().

◆ termlist_size

Xapian::termcount GlassTermList::termlist_size

private

The number of entries in this termlist.

Definition at line 58 of file glass_termlist.h.

Referenced by get_approx_size(), get_unique_terms(), and GlassTermList().

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

backends/glass/glass_termlist.h
backends/glass/glass_termlist.cc

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ GlassTermList() [1/2]

◆ GlassTermList() [2/2]

Member Function Documentation

◆ accumulate_stats()

◆ get_approx_size()

◆ get_doclength()

◆ get_termfreq()

◆ get_unique_terms()

◆ get_wdf()

◆ next()

◆ not_present()

◆ operator=()

◆ positionlist_begin()

◆ positionlist_count()

◆ skip_to()

Member Data Documentation

◆ current_termfreq

◆ current_wdf

◆ data

◆ db

◆ did

◆ doclen

◆ end

◆ pos

◆ termlist_size