The Xapian namespace contains public interfaces for the Xapian library. More...

Namespaces
namespace	Auto
	Database factory functions which determine the database type automatically.

namespace	Chert
	Database factory functions for the chert backend.

namespace	InMemory
	Database factory functions for the inmemory backend.

namespace	Remote
	Database factory functions for the remote backend.

namespace	Unicode
	Functions associated with handling Unicode characters.

Classes
class	AssertionError
	AssertionError is thrown if a logical assertion inside Xapian fails. More...

class	BB2Weight
	This class implements the BB2 weighting scheme. More...

class	BM25PlusWeight
	Xapian::Weight subclass implementing the BM25+ probabilistic formula. More...

class	BM25Weight
	Xapian::Weight subclass implementing the BM25 probabilistic formula. More...

class	BoolWeight
	Class implementing a "boolean" weighting scheme. More...

class	Compactor
	Compact a database, or merge and compact several. More...

class	CoordWeight
	Xapian::Weight subclass implementing Coordinate Matching. More...

class	Database
	This class is used to access a database, or a group of databases. More...

class	DatabaseClosedError
	Indicates an attempt to access a closed database. More...

class	DatabaseCorruptError
	DatabaseCorruptError indicates database corruption was detected. More...

class	DatabaseCreateError
	DatabaseCreateError indicates a failure to create a database. More...

class	DatabaseError
	DatabaseError indicates some sort of database related error. More...

class	DatabaseLockError
	DatabaseLockError indicates failure to lock a database. More...

class	DatabaseModifiedError
	DatabaseModifiedError indicates a database was modified. More...

class	DatabaseNotFoundError
	Indicates an attempt to access a database not present. More...

class	DatabaseOpeningError
	DatabaseOpeningError indicates failure to open a database. More...

class	DatabaseVersionError
	DatabaseVersionError indicates that a database is in an unsupported format. More...

class	DateRangeProcessor
	Handle a date range. More...

class	DateValueRangeProcessor
	Handle a date range. More...

class	DecreasingValueWeightPostingSource
	Read weights from a value which is known to decrease as docid increases. More...

class	DLHWeight
	This class implements the DLH weighting scheme, which is a representative scheme of the Divergence from Randomness Framework by Gianni Amati. More...

class	DocNotFoundError
	Indicates an attempt to access a document not present in the database. More...

class	Document
	A handle representing a document in a Xapian database. More...

class	DPHWeight
	This class implements the DPH weighting scheme. More...

class	Enquire
	This class provides an interface to the information retrieval system for the purpose of searching. More...

class	Error
	All exceptions thrown by Xapian are subclasses of Xapian::Error. More...

class	ErrorHandler
	Decide if a Xapian::Error exception should be ignored. More...

class	ESet
	Class representing a list of search results. More...

class	ESetIterator
	Iterator over a Xapian::ESet. More...

class	ExpandDecider
	Virtual base class for expand decider functor. More...

class	ExpandDeciderAnd
	ExpandDecider subclass which rejects terms using two ExpandDeciders. More...

class	ExpandDeciderFilterPrefix
	ExpandDecider subclass which restrict terms to a particular prefix. More...

class	ExpandDeciderFilterTerms
	ExpandDecider subclass which rejects terms in a specified list. More...

class	FeatureUnavailableError
	Indicates an attempt to use a feature which is unavailable. More...

class	FieldProcessor
	Base class for field processors. More...

class	FixedWeightPostingSource
	A posting source which returns a fixed weight for all documents. More...

class	GreatCircleMetric
	Calculate the great-circle distance between two coordinates on a sphere. More...

class	IfB2Weight
	This class implements the IfB2 weighting scheme. More...

class	IneB2Weight
	This class implements the IneB2 weighting scheme. More...

class	InL2Weight
	This class implements the InL2 weighting scheme. More...

class	InternalError
	InternalError indicates a runtime problem of some sort. More...

class	InvalidArgumentError
	InvalidArgumentError indicates an invalid parameter value was passed to the API. More...

class	InvalidOperationError
	InvalidOperationError indicates the API was used in an invalid way. More...

class	KeyMaker
	Virtual base class for key making functors. More...

struct	LatLongCoord
	A latitude-longitude coordinate. More...

class	LatLongCoords
	A sequence of latitude-longitude coordinates. More...

class	LatLongCoordsIterator
	An iterator across the values in a LatLongCoords object. More...

class	LatLongDistanceKeyMaker
	KeyMaker subclass which sorts by distance from a latitude/longitude. More...

class	LatLongDistancePostingSource
	Posting source which returns a weight based on geospatial distance. More...

class	LatLongMetric
	Base class for calculating distances between two lat/long coordinates. More...

class	LMWeight
	Xapian::Weight subclass implementing the Language Model formula. More...

class	LogicError
	The base class for exceptions indicating errors in the program logic. More...

class	MatchDecider
	Base class for matcher decision functor. More...

class	MatchSpy
	Abstract base class for match spies. More...

class	MSet
	Class representing a list of search results. More...

class	MSetIterator
	Iterator over a Xapian::MSet. More...

class	MultiValueKeyMaker
	KeyMaker subclass which combines several values. More...

class	NetworkError
	Indicates a problem communicating with a remote database. More...

class	NetworkTimeoutError
	Indicates a timeout expired while communicating with a remote database. More...

class	NumberRangeProcessor
	Handle a number range. More...

class	NumberValueRangeProcessor
	Handle a number range. More...

class	PL2PlusWeight
	Xapian::Weight subclass implementing the PL2+ probabilistic formula. More...

class	PL2Weight
	This class implements the PL2 weighting scheme. More...

class	PositionIterator
	Class for iterating over term positions. More...

class	PostingIterator
	Class for iterating over a list of terms. More...

class	PostingSource
	Base class which provides an "external" source of postings. More...

class	Query
	Class representing a query. More...

class	QueryParser
	Build a Xapian::Query object from a user query string. More...

class	QueryParserError
	Indicates a query string can't be parsed. More...

class	RangeError
	RangeError indicates an attempt to access outside the bounds of a container. More...

class	RangeProcessor
	Base class for range processors. More...

class	Registry
	Registry for user subclasses. More...

class	RSet
	A relevance set (R-Set). More...

class	RuntimeError
	The base class for exceptions indicating errors only detectable at runtime. More...

class	SerialisationError
	Indicates an error in the std::string serialisation of an object. More...

class	SimpleStopper
	Simple implementation of Stopper class - this will suit most users. More...

class	Stem
	Class representing a stemming algorithm. More...

class	StemImplementation
	Class representing a stemming algorithm implementation. More...

class	Stopper
	Abstract base class for stop-word decision functor. More...

class	StringValueRangeProcessor
	Handle a string range. More...

class	TermGenerator
	Parses a piece of text and generate terms. More...

class	TermIterator
	Class for iterating over a list of terms. More...

class	TfIdfWeight
	Xapian::Weight subclass implementing the tf-idf weighting scheme. More...

class	TradWeight
	Xapian::Weight subclass implementing the traditional probabilistic formula. More...

class	UnimplementedError
	UnimplementedError indicates an attempt to use an unimplemented feature. More...

class	Utf8Iterator
	An iterator which returns Unicode character values from a UTF-8 encoded string. More...

class	ValueCountMatchSpy
	Class for counting the frequencies of values in the matching documents. More...

class	ValueIterator
	Class for iterating over document values. More...

class	ValueMapPostingSource
	A posting source which looks up weights in a map using values as the key. More...

class	ValuePostingSource
	A posting source which generates weights from a value slot. More...

class	ValueRangeProcessor
	Base class for value range processors. More...

class	ValueSetMatchDecider
	MatchDecider filtering results based on whether document values are in a user-defined set. More...

class	ValueWeightPostingSource
	A posting source which reads weights from a value slot. More...

class	Weight
	Abstract base class for weighting schemes. More...

class	WildcardError
	WildcardError indicates an error expanding a wildcarded query. More...

class	WritableDatabase
	This class provides read/write access to a database. More...

Typedefs
typedef unsigned XAPIAN_DOCID_BASE_TYPE	doccount
	A count of documents.

typedef XAPIAN_DOCID_BASE_TYPE	doccount_diff
	A signed difference between two counts of documents.

typedef unsigned XAPIAN_DOCID_BASE_TYPE	docid
	A unique identifier for a document.

typedef double	doclength
	A normalised document length.

typedef int	percent
	The percentage score for a document in an MSet.

typedef unsigned XAPIAN_TERMCOUNT_BASE_TYPE	termcount
	A counts of terms.

typedef XAPIAN_TERMCOUNT_BASE_TYPE	termcount_diff
	A signed difference between two counts of terms.

typedef unsigned XAPIAN_TERMPOS_BASE_TYPE	termpos
	A term position within a document or query.

typedef XAPIAN_TERMPOS_BASE_TYPE	termpos_diff
	A signed difference between two term positions.

typedef unsigned	timeout
	A timeout value in milliseconds.

typedef unsigned	valueno
	The number for a value slot in a document.

typedef int	valueno_diff
	A signed difference between two value slot numbers.

typedef double	weight
	The weight of a document or term.

typedef XAPIAN_REVISION_TYPE	rev
	Revision number of a database.

typedef XAPIAN_TOTALLENGTH_TYPE	totallength
	The total length of all documents in a database.

Enumerations
enum	{ RP_SUFFIX = 1 , RP_REPEATED = 2 , RP_DATE_PREFER_MDY = 4 }

Functions
const char *	version_string ()
	Report the version string of the library which the program is linked with.

int	major_version ()
	Report the major version of the library which the program is linked with.

int	minor_version ()
	Report the minor version of the library which the program is linked with.

int	revision ()
	Report the revision of the library which the program is linked with.

bool	operator== (const ESetIterator &a, const ESetIterator &b)
	Equality test for ESetIterator objects.

bool	operator!= (const ESetIterator &a, const ESetIterator &b)
	Inequality test for ESetIterator objects.

bool	operator< (const ESetIterator &a, const ESetIterator &b)
	Inequality test for ESetIterator objects.

bool	operator> (const ESetIterator &a, const ESetIterator &b)
	Inequality test for ESetIterator objects.

bool	operator>= (const ESetIterator &a, const ESetIterator &b)
	Inequality test for ESetIterator objects.

bool	operator<= (const ESetIterator &a, const ESetIterator &b)
	Inequality test for ESetIterator objects.

ESetIterator	operator+ (ESetIterator::difference_type n, const ESetIterator &it)
	Return ESetIterator it incremented by n positions.

double	miles_to_metres (double miles)
	Convert from miles to metres.

double	metres_to_miles (double metres)
	Convert from metres to miles.

bool	operator!= (const LatLongCoordsIterator &a, const LatLongCoordsIterator &b)
	Inequality test for LatLongCoordsIterator objects.

bool	operator== (const MSetIterator &a, const MSetIterator &b)
	Equality test for MSetIterator objects.

bool	operator!= (const MSetIterator &a, const MSetIterator &b)
	Inequality test for MSetIterator objects.

bool	operator< (const MSetIterator &a, const MSetIterator &b)
	Inequality test for MSetIterator objects.

bool	operator> (const MSetIterator &a, const MSetIterator &b)
	Inequality test for MSetIterator objects.

bool	operator>= (const MSetIterator &a, const MSetIterator &b)
	Inequality test for MSetIterator objects.

bool	operator<= (const MSetIterator &a, const MSetIterator &b)
	Inequality test for MSetIterator objects.

MSetIterator	operator+ (MSetIterator::difference_type n, const MSetIterator &it)
	Return MSetIterator it incremented by n positions.

bool	operator== (const PositionIterator &a, const PositionIterator &b)
	Equality test for PositionIterator objects.

bool	operator!= (const PositionIterator &a, const PositionIterator &b)
	Inequality test for PositionIterator objects.

bool	operator== (const PostingIterator &a, const PostingIterator &b)
	Equality test for PostingIterator objects.

bool	operator!= (const PostingIterator &a, const PostingIterator &b)
	Inequality test for PostingIterator objects.

const Query	operator& (const Query &a, const Query &b)
	Combine two Xapian::Query objects using OP_AND.

const Query	operator\| (const Query &a, const Query &b)
	Combine two Xapian::Query objects using OP_OR.

const Query	operator^ (const Query &a, const Query &b)
	Combine two Xapian::Query objects using OP_XOR.

const Query	operator* (double factor, const Query &q)
	Scale a Xapian::Query object using OP_SCALE_WEIGHT.

const Query	operator* (const Query &q, double factor)
	Scale a Xapian::Query object using OP_SCALE_WEIGHT.

const Query	operator/ (const Query &q, double factor)
	Inverse-scale a Xapian::Query object using OP_SCALE_WEIGHT.

const Query	operator& (const Query &a, const InvertedQuery_ &b)
	Combine two Xapian::Query objects using OP_AND_NOT.

const Query	operator&= (Query &a, const InvertedQuery_ &b)
	Combine two Xapian::Query objects using OP_AND_NOT with result in the first.

std::string	sortable_serialise (double value)
	Convert a floating point number to a string, preserving sort order.

double	sortable_unserialise (const std::string &serialised)
	Convert a string encoded using sortable_serialise back to a floating point number.

bool	operator== (const TermIterator &a, const TermIterator &b)
	Equality test for TermIterator objects.

bool	operator!= (const TermIterator &a, const TermIterator &b)
	Inequality test for TermIterator objects.

bool	operator== (const ValueIterator &a, const ValueIterator &b)
	Equality test for ValueIterator objects.

bool	operator!= (const ValueIterator &a, const ValueIterator &b)
	Inequality test for ValueIterator objects.

Variables
const int	DB_CREATE_OR_OPEN = 0x00
	Create database if it doesn't already exist.

const int	DB_CREATE_OR_OVERWRITE = 0x01
	Create database if it doesn't already exist, or overwrite if it does.

const int	DB_CREATE = 0x02
	Create a new database.

const int	DB_OPEN = 0x03
	Open an existing database.

const int	DB_NO_SYNC = 0x04
	Don't attempt to ensure changes have hit disk.

const int	DB_FULL_SYNC = 0x08
	Try to ensure changes are really written to disk.

const int	DB_DANGEROUS = 0x10
	Update the database in-place.

const int	DB_NO_TERMLIST = 0x20
	When creating a database, don't create a termlist table.

const int	DB_RETRY_LOCK = 0x40
	If the database is already locked, retry the lock.

const int	DB_BACKEND_GLASS = 0x100
	Use the glass backend.

const int	DB_BACKEND_CHERT = 0x200
	Use the chert backend.

const int	DB_BACKEND_STUB = 0x300
	Open a stub database file.

const int	DB_BACKEND_INMEMORY = 0x400
	Use the "in memory" backend.

const int	DBCHECK_SHORT_TREE = 1
	Show a short-format display of the B-tree contents.

const int	DBCHECK_FULL_TREE = 2
	Show a full display of the B-tree contents.

const int	DBCHECK_SHOW_FREELIST = 4
	Show the bitmap for the B-tree.

const int	DBCHECK_SHOW_STATS = 8
	Show statistics for the B-tree.

const int	DBCHECK_FIX = 16
	Fix problems.

const int	DBCOMPACT_NO_RENUMBER = 4
	Use the same document ids in the output as in the input(s).

const int	DBCOMPACT_MULTIPASS = 8
	If merging more than 3 databases, merge the postlists in multiple passes.

const int	DBCOMPACT_SINGLE_FILE = 16
	Produce a single-file database.

const int	DOC_ASSUME_VALID = 1
	Assume document id is valid.

const valueno	BAD_VALUENO = 0xffffffff
	Reserved value to indicate "no valueno".

Detailed Description

The Xapian namespace contains public interfaces for the Xapian library.

Typedef Documentation

◆ doccount

typedef unsigned XAPIAN_DOCID_BASE_TYPE Xapian::doccount

A count of documents.

This is used to hold values such as the number of documents in a database and the frequency of a term in the database.

◆ doccount_diff

typedef XAPIAN_DOCID_BASE_TYPE Xapian::doccount_diff

A signed difference between two counts of documents.

This is used by the Xapian classes which are STL containers of documents for "difference_type".

◆ docid

typedef unsigned XAPIAN_DOCID_BASE_TYPE Xapian::docid

A unique identifier for a document.

Docid 0 is invalid, providing an "out of range" value which can be used to mean "not a valid document".

◆ doclength

typedef double Xapian::doclength

A normalised document length.

The normalised document length is the document length divided by the average document length in the database.

◆ percent

typedef int Xapian::percent

The percentage score for a document in an MSet.

Deprecated:: This type is deprecated as of Xapian 1.3.0 - use the standard type int instead, which should work with older Xapian too.

◆ rev

typedef XAPIAN_REVISION_TYPE Xapian::rev

Revision number of a database.

For databases which support this, it increases with each commit.

Experimental - see https://xapian.org/docs/deprecation#experimental-features

◆ termcount

typedef unsigned XAPIAN_TERMCOUNT_BASE_TYPE Xapian::termcount

A counts of terms.

This is used to hold values such as the Within Document Frequency (wdf).

◆ termcount_diff

typedef XAPIAN_TERMCOUNT_BASE_TYPE Xapian::termcount_diff

A signed difference between two counts of terms.

This is used by the Xapian classes which are STL containers of terms for "difference_type".

◆ termpos_diff

typedef XAPIAN_TERMPOS_BASE_TYPE Xapian::termpos_diff

A signed difference between two term positions.

This is used by the Xapian classes which are STL containers of positions for "difference_type".

◆ timeout

typedef unsigned Xapian::timeout

A timeout value in milliseconds.

There are 1000 milliseconds in a second, so for example, to set a timeout of 5 seconds use 5000.

Deprecated:: This type is deprecated as of Xapian 1.3.0 - use the standard POSIX type useconds_t instead, which should work with older Xapian too.

◆ totallength

typedef XAPIAN_TOTALLENGTH_TYPE Xapian::totallength

The total length of all documents in a database.

Added in Xapian 1.4.5.

◆ valueno

typedef unsigned Xapian::valueno

The number for a value slot in a document.

Value slot numbers are unsigned and (currently) a 32-bit quantity, with Xapian::BAD_VALUENO being represented by the largest possible value. Therefore value slots 0 to 0xFFFFFFFE are available for use.

◆ valueno_diff

typedef int Xapian::valueno_diff

A signed difference between two value slot numbers.

This is used by the Xapian classes which are STL containers of values for "difference_type".

◆ weight

typedef double Xapian::weight

The weight of a document or term.

Deprecated:: This type is deprecated as of Xapian 1.3.0 - use the standard C++ type double instead, which should work with older Xapian too.

Function Documentation

◆ major_version()

int Xapian::major_version ( )

inline

Report the major version of the library which the program is linked with.

This may be different to the version compiled against (given by XAPIAN_MAJOR_VERSION) if shared libraries are being used.

◆ metres_to_miles()

double Xapian::metres_to_miles ( double metres )

inline

Convert from metres to miles.

Experimental - see https://xapian.org/docs/deprecation#experimental-features

◆ miles_to_metres()

double Xapian::miles_to_metres ( double miles )

inline

Convert from miles to metres.

Experimental - see https://xapian.org/docs/deprecation#experimental-features

◆ minor_version()

int Xapian::minor_version ( )

inline

Report the minor version of the library which the program is linked with.

This may be different to the version compiled against (given by XAPIAN_MINOR_VERSION) if shared libraries are being used.

◆ operator&()

const Query Xapian::operator&	(	const Query &	a,
		const InvertedQuery_ &	b
	)

inline

Combine two Xapian::Query objects using OP_AND_NOT.

E.g. Xapian::Query q = q1 &~ q2;

References Xapian::Query::OP_AND_NOT.

◆ operator&=()

const Query Xapian::operator&=	(	Query &	a,
		const InvertedQuery_ &	b
	)

inline

Combine two Xapian::Query objects using OP_AND_NOT with result in the first.

E.g. q1 &=~ q2;

References Xapian::Query::OP_AND_NOT.

◆ operator*() [1/2]

const Query Xapian::operator*	(	const Query &	q,
		double	factor
	)

inline

Scale a Xapian::Query object using OP_SCALE_WEIGHT.

Parameters

q	Xapian::Query object.
factor	Non-negative real number to multiply weights by.

◆ operator*() [2/2]

const Query Xapian::operator*	(	double	factor,
		const Query &	q
	)

inline

Scale a Xapian::Query object using OP_SCALE_WEIGHT.

Parameters

factor	Non-negative real number to multiply weights by.
q	Xapian::Query object.

◆ operator+() [1/2]

ESetIterator Xapian::operator+	(	ESetIterator::difference_type	n,
		const ESetIterator &	it
	)

inline

Return ESetIterator it incremented by n positions.

If n is negative, decrements by (-n) positions.

◆ operator+() [2/2]

MSetIterator Xapian::operator+	(	MSetIterator::difference_type	n,
		const MSetIterator &	it
	)

inline

Return MSetIterator it incremented by n positions.

If n is negative, decrements by (-n) positions.

◆ operator/()

const Query Xapian::operator/	(	const Query &	q,
		double	factor
	)

inline

Inverse-scale a Xapian::Query object using OP_SCALE_WEIGHT.

Parameters

factor	Positive real number to divide weights by.
q	Xapian::Query object.

◆ revision()

int Xapian::revision ( )

inline

Report the revision of the library which the program is linked with.

This may be different to the version compiled against (given by XAPIAN_REVISION) if shared libraries are being used.

◆ sortable_serialise()

std::string Xapian::sortable_serialise ( double value )

inline

Convert a floating point number to a string, preserving sort order.

This method converts a floating point number to a string, suitable for using as a value for numeric range restriction, or for use as a sort key.

The conversion is platform independent.

The conversion attempts to ensure that, for any pair of values supplied to the conversion algorithm, the result of comparing the original values (with a numeric comparison operator) will be the same as the result of comparing the resulting values (with a string comparison operator). On platforms which represent doubles with the precisions specified by IEEE_754, this will be the case: if the representation of doubles is more precise, it is possible that two very close doubles will be mapped to the same string, so will compare equal.

Note also that both zero and -zero will be converted to the same representation: since these compare equal, this satisfies the comparison constraint, but it's worth knowing this if you wish to use the encoding in some situation where this distinction matters.

Handling of NaN isn't (currently) guaranteed to be sensible.

Parameters

value The number to serialise.

Referenced by Xapian::LatLongDistanceKeyMaker::LatLongDistanceKeyMaker(), and Xapian::LatLongDistanceKeyMaker::LatLongDistanceKeyMaker().

◆ sortable_unserialise()

double Xapian::sortable_unserialise ( const std::string & serialised )

Convert a string encoded using sortable_serialise back to a floating point number.

This expects the input to be a string produced by sortable_serialise(). If the input is not such a string, the value returned is undefined (but no error will be thrown).

The result of the conversion will be exactly the value which was supplied to sortable_serialise() when making the string on platforms which represent doubles with the precisions specified by IEEE_754, but may be a different (nearby) value on other platforms.

Parameters

serialised The serialised string to decode.

◆ version_string()

const char * Xapian::version_string ( )

inline

Report the version string of the library which the program is linked with.

This may be different to the version compiled against (given by XAPIAN_VERSION) if shared libraries are being used.

Variable Documentation

◆ DB_BACKEND_CHERT

const int Xapian::DB_BACKEND_CHERT = 0x200

Use the chert backend.

When opening a WritableDatabase, this means create a chert database if a new database is created. If there's an existing database (of any type) at the specified path, this flag has no effect.

When opening a Database, this flag means to only open it if it's a chert database. There's rarely a good reason to do this - it's mostly provided as equivalent functionality to Xapian::Chert::open() in Xapian 1.2.

Referenced by Xapian::Chert::open(), and Xapian::Chert::open().

◆ DB_BACKEND_GLASS

const int Xapian::DB_BACKEND_GLASS = 0x100

Use the glass backend.

When opening a WritableDatabase, this means create a glass database if a new database is created. If there's an existing database (of any type) at the specified path, this flag has no effect.

When opening a Database, this flag means to only open it if it's a glass database. There's rarely a good reason to do this - it's mostly provided as equivalent functionality to that provided by the namespaced open() functions in Xapian 1.2.

◆ DB_BACKEND_INMEMORY

const int Xapian::DB_BACKEND_INMEMORY = 0x400

Use the "in memory" backend.

The filename is currently ignored when this flag is used, but an empty string should be passed to allow for future expansion.

A new empty database is created, so when creating a Database object this creates an empty read-only database - sometimes useful to avoid special casing this situation, but otherwise of limited use. It's more useful when creating a WritableDatabase object, though beware that the current inmemory backend implementation was not built for performance and scalability.

This provides an equivalent to Xapian::InMemory::open() in Xapian 1.2.

Referenced by Xapian::InMemory::open().

◆ DB_BACKEND_STUB

const int Xapian::DB_BACKEND_STUB = 0x300

Open a stub database file.

When opening a Database, this flag means to only open it if it's a stub database file. There's rarely a good reason to do this - it's mostly provided as equivalent functionality to Xapian::Auto::open_stub() in Xapian 1.2.

Referenced by Xapian::Auto::open_stub(), and Xapian::Auto::open_stub().

◆ DB_CREATE

const int Xapian::DB_CREATE = 0x02

Create a new database.

If the database already exists, an exception will be thrown.

◆ DB_CREATE_OR_OPEN

const int Xapian::DB_CREATE_OR_OPEN = 0x00

Create database if it doesn't already exist.

If no opening mode is specified, this is the default.

◆ DB_DANGEROUS

const int Xapian::DB_DANGEROUS = 0x10

Update the database in-place.

Xapian's disk-based backends use block-based storage, with copy-on-write to allow the previous revision to be searched while a new revision forms.

This option means changed blocks get written back over the top of the old version. The benefits of this are that less I/O is required during indexing, and the result of indexing is more compact. The downsides are that you can't concurrently search while indexing, transactions can't be cancelled, and if indexing ends uncleanly (i.e. without commit() or WritableDatabase's destructor being called) then the database won't be usable.

Currently all the base files will be removed upon the first modification, and new base files will be written upon commit. This prevents new readers from opening the database while it unsafe to do so, but there's not currently a mechanism in Xapian to handle notifying existing readers.

◆ DB_FULL_SYNC

const int Xapian::DB_FULL_SYNC = 0x08

Try to ensure changes are really written to disk.

Generally fsync() and similar functions only ensure that data has been sent to the drive. Modern drives have large write-back caches for performance, and a power failure could still lose data which is in the write-back cache waiting to be written.

Some platforms provide a way to ensure data has actually been written and setting DB_FULL_SYNC will attempt to do so where possible. The downside is that committing changes takes longer, and other I/O to the same disk may be delayed too.

Currently only macOS is supported, and only on some filing system types

if not supported, Xapian will use fsync() or similar instead.

◆ DB_NO_SYNC

const int Xapian::DB_NO_SYNC = 0x04

Don't attempt to ensure changes have hit disk.

By default, Xapian ask the OS to ensure changes have hit disk (by calling fdatasync(), fsync() or similar functions). If these calls do their job, this should mean that when WritableDatabase::commit() returns, the changes are durable, but this comes at a performance cost, and if you don't mind losing changes in the case of a crash, power failure, etc, then this option can speed up indexing significantly.

◆ DB_NO_TERMLIST

const int Xapian::DB_NO_TERMLIST = 0x20

When creating a database, don't create a termlist table.

For backends which support it (currently glass), this will prevent creation of a termlist table. This saves on the disk space that would be needed to store it, and the CPU and I/O needed to update it, but some features either inherently need the termlist table, or the current implementation of them requires it.

The following probably can't be sensibly implemented without it:

And the following currently require it:

Enquire::matching_terms_begin() - we could record this information during the match, though it might be hard to do without a speed penalty.
WritableDatabase::delete_document() - we could allow this with inexact statistics (like how Lucene does).
WritableDatabase::replace_document() if the document exists already (again, possible with inexact statistics).
Currently the list of which values are used in each document is stored in the termlist table, so things like iterating the values in a document require it (which is probably reasonable since iterating the terms in a document requires it).

You can also convert an existing database to not have a termlist table by simply deleting termlist.*.

◆ DB_OPEN

const int Xapian::DB_OPEN = 0x03

Open an existing database.

If the database doesn't exist, an exception will be thrown.

◆ DB_RETRY_LOCK

const int Xapian::DB_RETRY_LOCK = 0x40

If the database is already locked, retry the lock.

By default, if the database is already locked by a writer, trying to open it again for writing will fail by throwing Xapian::DatabaseLockError. If this flag is specified, then Xapian will instead wait for the lock (indefinitely, unless it gets an error trying to do so).

◆ DBCHECK_FIX

const int Xapian::DBCHECK_FIX = 16

Fix problems.

For use with Xapian::Database::check().

Currently this is supported for chert, and will:

regenerate the "iamchert" file if it isn't valid (so if it is lost, you can just create it empty and then "fix problems").

regenerate base files (currently the algorithm for finding the root block may not work if there was a change partly written but not committed).

◆ DBCHECK_FULL_TREE

const int Xapian::DBCHECK_FULL_TREE = 2

Show a full display of the B-tree contents.

For use with Xapian::Database::check().

◆ DBCHECK_SHORT_TREE

const int Xapian::DBCHECK_SHORT_TREE = 1

Show a short-format display of the B-tree contents.

For use with Xapian::Database::check().

◆ DBCHECK_SHOW_FREELIST

const int Xapian::DBCHECK_SHOW_FREELIST = 4

Show the bitmap for the B-tree.

For use with Xapian::Database::check().

◆ DBCHECK_SHOW_STATS

const int Xapian::DBCHECK_SHOW_STATS = 8

Show statistics for the B-tree.

For use with Xapian::Database::check().

◆ DBCOMPACT_MULTIPASS

const int Xapian::DBCOMPACT_MULTIPASS = 8

If merging more than 3 databases, merge the postlists in multiple passes.

This is generally faster but requires more disk space for temporary files.

Referenced by Xapian::Compactor::set_multipass().

◆ DBCOMPACT_NO_RENUMBER

const int Xapian::DBCOMPACT_NO_RENUMBER = 4

Use the same document ids in the output as in the input(s).

By default compaction renumbers the document ids in the output database, currently by applying the same offset to all the document ids in a particular source database. If this flag is specified, then this renumbering doesn't happen, but all the document ids must be unique over all source databases. Currently the ranges of document ids in each source must not overlap either, though this restriction may be removed in the future.

Referenced by Xapian::Compactor::set_renumber().

◆ DBCOMPACT_SINGLE_FILE

const int Xapian::DBCOMPACT_SINGLE_FILE = 16

Produce a single-file database.

Only supported by the glass backend currently.

◆ DOC_ASSUME_VALID

const int Xapian::DOC_ASSUME_VALID = 1

Assume document id is valid.

By default, Database::get_document() checks that the document id passed is actually in use and throws DocNotFoundError if not. This flag can be used to disable this check - useful to save a bit of work when you know for sure that the document id is valid.

Some database backends may check anyway - the remote backend currently does.

Namespaces

Classes

Typedefs

Enumerations

Functions

Variables

Detailed Description

Typedef Documentation

◆ doccount

◆ doccount_diff

◆ docid

◆ doclength

◆ percent

◆ rev

◆ termcount

◆ termcount_diff

◆ termpos_diff

◆ timeout

◆ totallength

◆ valueno

◆ valueno_diff

◆ weight

Function Documentation

◆ major_version()

◆ metres_to_miles()

◆ miles_to_metres()

◆ minor_version()

◆ operator&()

◆ operator&=()

◆ operator*() [1/2]

◆ operator*() [2/2]

◆ operator+() [1/2]

◆ operator+() [2/2]

◆ operator/()

◆ revision()

◆ sortable_serialise()

◆ sortable_unserialise()

◆ version_string()

Variable Documentation

◆ DB_BACKEND_CHERT

◆ DB_BACKEND_GLASS

◆ DB_BACKEND_INMEMORY

◆ DB_BACKEND_STUB

◆ DB_CREATE

◆ DB_CREATE_OR_OPEN

◆ DB_DANGEROUS

◆ DB_FULL_SYNC

◆ DB_NO_SYNC

◆ DB_NO_TERMLIST

◆ DB_OPEN

◆ DB_RETRY_LOCK

◆ DBCHECK_FIX

◆ DBCHECK_FULL_TREE

◆ DBCHECK_SHORT_TREE

◆ DBCHECK_SHOW_FREELIST

◆ DBCHECK_SHOW_STATS

◆ DBCOMPACT_MULTIPASS

◆ DBCOMPACT_NO_RENUMBER

◆ DBCOMPACT_SINGLE_FILE

◆ DOC_ASSUME_VALID