QuartzWritableDatabase Class Reference

A writable quartz database. More...

#include <quartz_database.h>

Inheritance diagram for QuartzWritableDatabase:

[legend]Collaboration diagram for QuartzWritableDatabase:


Public Member Functions
	QuartzWritableDatabase (const string &dir, int action, int block_size)
	Create and open a writable quartz database.
	~QuartzWritableDatabase ()

Xapian::doccount	get_doccount () const
	Virtual methods of Database.
Xapian::docid	get_lastdocid () const
	Return the last used document id of this (sub) database.
Xapian::doclength	get_avlength () const
	Return the average length of a document in this (sub) database.
Xapian::doclength	get_doclength (Xapian::docid did) const
	Get the length of a given document.
Xapian::doccount	get_termfreq (const string &tname) const
	Return the number of documents indexed by a given term.
Xapian::termcount	get_collection_freq (const string &tname) const
	Return the total number of occurrences of the given term.
bool	term_exists (const string &tname) const
	Check whether a given term is in the database.
bool	has_positions () const
	Check whether this database contains any positional information.
LeafPostList *	open_post_list (const string &tname) const
	Open a posting list.
TermList *	open_term_list (Xapian::docid did) const
	Open a term list.
Xapian::Document::Internal *	open_document (Xapian::docid did, bool lazy=false) const
	Open a document.
PositionList *	open_position_list (Xapian::docid did, const string &tname) const
	Open a position list for the given term in the given document.
TermList *	open_allterms (const string &prefix) const
	Open an allterms list.
Private Member Functions

void	flush ()
	Implementation of virtual methods: see Database for details.
void	do_flush_const () const
void	cancel ()
	Cancel pending modifications to the database.
virtual Xapian::docid	add_document (const Xapian::Document &document)
	Add a new document to the database.
Xapian::docid	add_document_ (Xapian::docid did, const Xapian::Document &document)
virtual void	delete_document (Xapian::docid did)
	Delete a document in the database.
virtual void	replace_document (Xapian::docid did, const Xapian::Document &document)
	Replace a given document in the database.
Private Attributes
map< string, pair< Xapian::termcount_diff, Xapian::termcount_diff > >	freq_deltas
	Unflushed changes to term frequencies and collection frequencies.
map< Xapian::docid, Xapian::termcount >	doclens
	Document lengths of new and modified documents which haven't been flushed yet.
map< string, map< Xapian::docid, pair< char, Xapian::termcount > > >	mod_plists
	Modifications to posting lists.
QuartzDatabase	database_ro
	The readonly database encapsulated in the writable database.
quartz_totlen_t	total_length
	Total length of all documents including unflushed modifications.
Xapian::docid	lastdocid
	Highest document ID ever allocated by this database.
Xapian::doccount	changes_made
	The number of documents added, deleted, or replaced since the last flush.
Static Private Attributes
static size_t	flush_threshold = 0

Detailed Description

A writable quartz database.

Definition at line 229 of file quartz_database.h.

Constructor & Destructor Documentation

QuartzWritableDatabase::QuartzWritableDatabase	(	const string &	dir,
		int	action,
		int	block_size
	)

Create and open a writable quartz database.

Exceptions:

	Xapian::DatabaseOpeningError	thrown if database can't be opened.
	Xapian::DatabaseVersionError	thrown if database is in an unsupported format. This implies that the database was created by an older or newer version of Xapian.

Parameters:

dir

directory holding quartz tables

Definition at line 669 of file quartz_database.cc.

References atoi(), DEBUGCALL, and flush_threshold.

QuartzWritableDatabase::~QuartzWritableDatabase ( )

Definition at line 688 of file quartz_database.cc.

References DEBUGCALL, and Xapian::Database::Internal::dtor_called().

Member Function Documentation

void QuartzWritableDatabase::flush ( ) [private, virtual]

Implementation of virtual methods: see Database for details.

Reimplemented from Xapian::Database::Internal.

Definition at line 695 of file quartz_database.cc.

References changes_made, do_flush_const(), and Xapian::Database::Internal::transaction_active().

void QuartzWritableDatabase::do_flush_const ( ) const [private]

Definition at line 703 of file quartz_database.cc.

References QuartzDatabase::apply(), changes_made, database_ro, DEBUGCALL, doclens, freq_deltas, lastdocid, QuartzPostListTable::merge_changes(), mod_plists, QuartzDatabase::postlist_table, QuartzDatabase::record_table, QuartzRecordTable::set_total_length_and_lastdocid(), and total_length.

Referenced by add_document_(), delete_document(), flush(), open_allterms(), open_post_list(), and replace_document().

void QuartzWritableDatabase::cancel ( ) [private, virtual]

Cancel pending modifications to the database.

Reimplemented from Xapian::Database::Internal.

Definition at line 1201 of file quartz_database.cc.

References QuartzDatabase::cancel(), changes_made, database_ro, doclens, freq_deltas, QuartzDatabase::get_lastdocid(), QuartzRecordTable::get_total_length(), lastdocid, mod_plists, QuartzDatabase::record_table, and total_length.

Referenced by add_document_(), delete_document(), and replace_document().

Xapian::docid QuartzWritableDatabase::add_document ( const Xapian::Document & document ) [private, virtual]

Add a new document to the database.

See WritableDatabase::add_document() for more information.

Reimplemented from Xapian::Database::Internal.

Definition at line 720 of file quartz_database.cc.

References add_document_(), DEBUGCALL, lastdocid, and RETURN.

Xapian::docid QuartzWritableDatabase::add_document_	(	Xapian::docid	did,
		const Xapian::Document &	document
	)			`[private]`

Definition at line 732 of file quartz_database.cc.

References Assert, cancel(), changes_made, database_ro, do_flush_const(), doclens, QuartzValueTable::encode_values(), flush_threshold, freq_deltas, Xapian::Document::get_data(), Xapian::TermIterator::get_wdf(), mod_plists, Xapian::TermIterator::positionlist_begin(), Xapian::TermIterator::positionlist_end(), QuartzDatabase::positionlist_table, QuartzDatabase::record_table, QuartzRecordTable::replace_record(), QuartzValueTable::set_encoded_values(), QuartzTermListTable::set_entries(), QuartzPositionListTable::set_positionlist(), Xapian::Document::termlist_begin(), Xapian::Document::termlist_end(), QuartzDatabase::termlist_table, total_length, Xapian::Database::Internal::transaction_active(), QuartzDatabase::value_table, Xapian::Document::values_begin(), and Xapian::Document::values_end().

Referenced by add_document(), and replace_document().

void QuartzWritableDatabase::delete_document ( Xapian::docid did ) [private, virtual]

Delete a document in the database.

See WritableDatabase::delete_document() for more information.

Reimplemented from Xapian::Database::Internal.

Definition at line 821 of file quartz_database.cc.

References Assert, QuartzTermList::at_end(), cancel(), changes_made, database_ro, DEBUGCALL, QuartzValueTable::delete_all_values(), QuartzPositionListTable::delete_positionlist(), QuartzRecordTable::delete_record(), QuartzTermListTable::delete_termlist(), do_flush_const(), doclens, flush_threshold, freq_deltas, get_doccount(), QuartzTermList::get_doclength(), QuartzTermList::get_termname(), QuartzTermList::get_wdf(), mod_plists, QuartzTermList::next(), QuartzDatabase::positionlist_table, QuartzDatabase::record_table, QuartzDatabase::termlist_table, total_length, Xapian::Database::Internal::transaction_active(), and QuartzDatabase::value_table.

void QuartzWritableDatabase::replace_document	(	Xapian::docid	did,
		const Xapian::Document &	document
	)			`[private, virtual]`

Replace a given document in the database.

See WritableDatabase::replace_document() for more information.

Reimplemented from Xapian::Database::Internal.

Definition at line 897 of file quartz_database.cc.

References add_document_(), Assert, QuartzTermList::at_end(), cancel(), changes_made, database_ro, DEBUGCALL, QuartzValueTable::delete_all_values(), QuartzPositionListTable::delete_positionlist(), do_flush_const(), doclens, QuartzValueTable::encode_values(), flush_threshold, freq_deltas, Xapian::Document::get_data(), get_doccount(), QuartzTermList::get_doclength(), QuartzTermList::get_termname(), Xapian::TermIterator::get_wdf(), QuartzTermList::get_wdf(), lastdocid, mod_plists, QuartzTermList::next(), Xapian::TermIterator::positionlist_begin(), Xapian::TermIterator::positionlist_end(), QuartzDatabase::positionlist_table, QuartzDatabase::record_table, QuartzRecordTable::replace_record(), QuartzValueTable::set_encoded_values(), QuartzTermListTable::set_entries(), QuartzPositionListTable::set_positionlist(), Xapian::Document::termlist_begin(), Xapian::Document::termlist_end(), QuartzDatabase::termlist_table, total_length, Xapian::Database::Internal::transaction_active(), QuartzDatabase::value_table, Xapian::Document::values_begin(), and Xapian::Document::values_end().

Xapian::doccount QuartzWritableDatabase::get_doccount ( ) const [virtual]

Virtual methods of Database.

Implements Xapian::Database::Internal.

Definition at line 1043 of file quartz_database.cc.

References database_ro, DEBUGCALL, QuartzDatabase::get_doccount(), and RETURN.

Referenced by delete_document(), open_post_list(), open_term_list(), and replace_document().

Xapian::docid QuartzWritableDatabase::get_lastdocid ( ) const [virtual]

Return the last used document id of this (sub) database.

Implements Xapian::Database::Internal.

Definition at line 1050 of file quartz_database.cc.

References DEBUGCALL, lastdocid, and RETURN.

Xapian::doclength QuartzWritableDatabase::get_avlength ( ) const [virtual]

Return the average length of a document in this (sub) database.

See Database::Internal::get_doclength() for the meaning of document length within Xapian.

Implements Xapian::Database::Internal.

Definition at line 1057 of file quartz_database.cc.

References database_ro, DEBUGCALL, QuartzDatabase::get_doccount(), RETURN, and total_length.

Xapian::doclength QuartzWritableDatabase::get_doclength ( Xapian::docid did ) const [virtual]

Get the length of a given document.

Document length, for the purposes of Xapian, is defined to be the number of instances of terms within a document. Expressed differently, the sum of the within document frequencies over all the terms in the document.

Parameters:

did

The document id of the document whose length is being requested.

Implements Xapian::Database::Internal.

Definition at line 1066 of file quartz_database.cc.

References database_ro, DEBUGCALL, doclens, QuartzDatabase::get_doclength(), and RETURN.

Xapian::doccount QuartzWritableDatabase::get_termfreq ( const string & tname ) const [virtual]

Return the number of documents indexed by a given term.

This may be an approximation, but must be an upper bound (ie, greater or equal to the true value), and should be as accurate as possible.

Parameters:

tname

The term whose term frequency is being requested.

Implements Xapian::Database::Internal.

Definition at line 1076 of file quartz_database.cc.

References database_ro, DEBUGCALL, freq_deltas, QuartzDatabase::get_termfreq(), and RETURN.

Referenced by term_exists().

Xapian::termcount QuartzWritableDatabase::get_collection_freq ( const string & tname ) const [virtual]

Return the total number of occurrences of the given term.

This is the sum of the number of ocurrences of the term in each document: ie, the sum of the within document frequencies of the term.

Parameters:

tname

The term whose collection frequency is being requested.

Implements Xapian::Database::Internal.

Definition at line 1087 of file quartz_database.cc.

References database_ro, DEBUGCALL, freq_deltas, QuartzDatabase::get_collection_freq(), and RETURN.

bool QuartzWritableDatabase::term_exists ( const string & tname ) const [virtual]

Check whether a given term is in the database.

Parameters:

tname

The term whose presence is being checked.

Implements Xapian::Database::Internal.

Definition at line 1100 of file quartz_database.cc.

References DEBUGCALL, get_termfreq(), and RETURN.

bool QuartzWritableDatabase::has_positions ( ) const [virtual]

Check whether this database contains any positional information.

Implements Xapian::Database::Internal.

Definition at line 1107 of file quartz_database.cc.

References database_ro, and QuartzDatabase::has_positions().

LeafPostList * QuartzWritableDatabase::open_post_list ( const string & tname ) const [virtual]

Open a posting list.

Method defined by subclass to open a posting list. This is a list of all the documents which contain a given term.

Parameters:

tname

The term whose posting list is being requested.

Returns:: A pointer to the newly created posting list. If the term doesn't exist, a new EmptyPostList object (or an object which behaves the same way) is returned instead, which makes it easier to implement a search over multiple databases. This object must be deleted by the caller after use.

Implements Xapian::Database::Internal.

Definition at line 1114 of file quartz_database.cc.

References database_ro, DEBUGCALL, do_flush_const(), get_doccount(), mod_plists, QuartzDatabase::positionlist_table, QuartzDatabase::postlist_table, RETURN, QuartzDatabase::termlist_table, and Xapian::Database::Internal::transaction_active().

TermList * QuartzWritableDatabase::open_term_list ( Xapian::docid did ) const [virtual]

Open a term list.

This is a list of all the terms contained by a given document.

Parameters:

did

The document id whose term list is being requested.

Returns:: A pointer to the newly created term list. This object must be deleted by the caller after use.

Implements Xapian::Database::Internal.

Definition at line 1141 of file quartz_database.cc.

References Assert, database_ro, DEBUGCALL, get_doccount(), RETURN, and QuartzDatabase::termlist_table.

Referenced by open_position_list().

Xapian::Document::Internal * QuartzWritableDatabase::open_document	(	Xapian::docid	did,
		bool	lazy = `false`
	)			const `[virtual]`

Open a document.

This is used to access the values and data associated with a document. See class Xapian::Document::Internal for further details.

Parameters:

	did	The document id which is being requested.
	lazy	Don't check the document exists immediately - use from within the matcher where we know the document exists, and don't want to read the record when we just want the values.