Class representing a query. More...

#include <query.h>

Collaboration diagram for Xapian::Query:

Classes
class	Internal

Public Types
enum	op { OP_AND = 0 , OP_OR = 1 , OP_AND_NOT = 2 , OP_XOR = 3 , OP_AND_MAYBE = 4 , OP_FILTER = 5 , OP_NEAR = 6 , OP_PHRASE = 7 , OP_VALUE_RANGE = 8 , OP_SCALE_WEIGHT = 9 , OP_ELITE_SET = 10 , OP_VALUE_GE = 11 , OP_VALUE_LE = 12 , OP_SYNONYM = 13 , OP_MAX = 14 , OP_WILDCARD = 15 , OP_EDIT_DISTANCE = 16 , OP_INVALID = 99 , LEAF_TERM = 100 , LEAF_POSTING_SOURCE , LEAF_MATCH_ALL , LEAF_MATCH_NOTHING }
	Query operators. More...

enum	{ WILDCARD_LIMIT_ERROR = 0x00 , WILDCARD_LIMIT_FIRST = 0x01 , WILDCARD_LIMIT_MOST_FREQUENT = 0x02 , WILDCARD_LIMIT_MASK_ = 0x03 , WILDCARD_PATTERN_MULTI = 0x10 , WILDCARD_PATTERN_SINGLE = 0x20 , WILDCARD_PATTERN_GLOB = WILDCARD_PATTERN_MULTI\|WILDCARD_PATTERN_SINGLE }

Public Member Functions
	Query () noexcept
	Construct a query matching no documents. More...

	~Query ()
	Destructor. More...

	Query (const Query &o)
	Copying is allowed. More...

Query &	operator= (const Query &o)
	Copying is allowed. More...

	Query (Query &&)=default
	Move constructor. More...

Query &	operator= (Query &&)=default
	Move assignment operator. More...

	Query (const std::string &term, Xapian::termcount wqf=1, Xapian::termpos pos=0)
	Construct a Query object for a term. More...

	Query (const char *term, Xapian::termcount wqf=1, Xapian::termpos pos=0)
	Construct a Query object for a term. More...

	Query (std::string_view term, Xapian::termcount wqf=1, Xapian::termpos pos=0)
	Construct a Query object for a term. More...

	Query (Xapian::PostingSource *source)
	Construct a Query object for a PostingSource. More...

	Query (double factor, const Xapian::Query &subquery)
	Scale using OP_SCALE_WEIGHT. More...

	Query (op op_, const Xapian::Query &subquery, double factor)
	Scale using OP_SCALE_WEIGHT. More...

	Query (op op_, const Xapian::Query &a, const Xapian::Query &b)
	Construct a Query object by combining two others. More...

template<typename S1 , typename S2 , typename std::enable_if< std::is_constructible< std::string_view, S1 >::value &&std::is_constructible< std::string_view, S2 >::value, bool >::type = true>
	Query (op op_, S1 a, S2 b)
	Construct a Query object by combining two terms. More...

	Query (op op_, Xapian::valueno slot, std::string_view range_limit)
	Construct a Query object for a single-ended value range. More...

	Query (op op_, Xapian::valueno slot, std::string_view range_lower, std::string_view range_upper)
	Construct a Query object for a value range. More...

	Query (op op_, std::string_view pattern, Xapian::termcount max_expansion=0, int flags=WILDCARD_LIMIT_ERROR, op combiner=OP_SYNONYM)
	Query constructor for OP_EDIT_DISTANCE and OP_WILDCARD queries. More...

	Query (op op_, std::string_view pattern, Xapian::termcount max_expansion, int flags, op combiner, unsigned edit_distance, size_t min_prefix_len=0)
	Query constructor for OP_EDIT_DISTANCE queries. More...

template<typename I , typename std::enable_if< std::is_convertible< typename std::iterator_traits< I >::value_type, Xapian::Query >::value\|\|std::is_convertible< typename std::iterator_traits< I >::value_type, Xapian::Query * >::value\|\|std::is_convertible< typename std::iterator_traits< I >::value_type, std::string_view >::value, bool >::type = true, typename iterator_category = typename std::iterator_traits<I>::iterator_category>
	Query (op op_, I begin, I end, Xapian::termcount window=0)
	Construct a Query object from a begin/end iterator pair. More...

const TermIterator	get_terms_begin () const
	Begin iterator for terms in the query object. More...

const TermIterator	get_terms_end () const noexcept
	End iterator for terms in the query object. More...

const TermIterator	get_unique_terms_begin () const
	Begin iterator for unique terms in the query object. More...

const TermIterator	get_unique_terms_end () const noexcept
	End iterator for unique terms in the query object. More...

Xapian::termcount	get_length () const noexcept
	Return the length of this query object. More...

bool	empty () const noexcept
	Check if this query is Xapian::Query::MatchNothing. More...

std::string	serialise () const
	Serialise this object into a string. More...

op	get_type () const noexcept
	Get the type of the top level of the query. More...

size_t	get_num_subqueries () const noexcept
	Get the number of subqueries of the top level query. More...

Xapian::termcount	get_leaf_wqf () const
	Get the wqf parameter of a leaf node. More...

Xapian::termpos	get_leaf_pos () const
	Get the pos parameter of a leaf node. More...

const Query	get_subquery (size_t n) const
	Read a top level subquery. More...

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

const Query	operator&= (const Query &o)
	Combine with another Xapian::Query object using OP_AND. More...

const Query	operator\|= (const Query &o)
	Combine with another Xapian::Query object using OP_OR. More...

const Query	operator^= (const Query &o)
	Combine with another Xapian::Query object using OP_XOR. More...

const Query	operator*= (double factor)
	Scale using OP_SCALE_WEIGHT. More...

const Query	operator/= (double factor)
	Inverse scale using OP_SCALE_WEIGHT. More...

	Query (Query::op op_)
	Construct with just an operator. More...

Static Public Member Functions
static const Query	unserialise (std::string_view serialised, const Registry &reg=Registry())
	Unserialise a string and return a Query object. More...

Static Public Attributes
static const Xapian::Query	MatchNothing
	A query matching no documents. More...

static const Xapian::Query	MatchAll
	A query matching all documents. More...

Private Member Functions
	Query (Internal *internal_)

void	init (Query::op op_, size_t n_subqueries, Xapian::termcount window=0)

template<typename I >
void	init (Query::op op_, Xapian::termcount window, const I &begin, const I &end, std::random_access_iterator_tag)

template<typename I >
void	init (Query::op op_, Xapian::termcount window, const I &, const I &, std::input_iterator_tag)

void	add_subquery (bool positional, const Xapian::Query &subquery)

void	add_subquery (bool, const std::string &subquery)

void	add_subquery (bool, const char *subquery)

void	add_subquery (bool, std::string_view subquery)

void	add_subquery (bool positional, const Xapian::Query *subquery)

void	done ()

Private Attributes
Xapian::Internal::intrusive_ptr< Internal >	internal

Detailed Description

Class representing a query.

Definition at line 45 of file query.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Enumerator
WILDCARD_LIMIT_ERROR	Throw an error if OP_WILDCARD exceeds its expansion limit. Xapian::WildcardError will be thrown when the query is actually run.
WILDCARD_LIMIT_FIRST	Stop expanding when OP_WILDCARD reaches its expansion limit. This makes the wildcard expand to only the first N terms (sorted by byte order).
WILDCARD_LIMIT_MOST_FREQUENT	Limit OP_WILDCARD expansion to the most frequent terms. If OP_WILDCARD would expand to more than its expansion limit, the most frequent terms are taken. This approach works well for cases such as expanding a partial term at the end of a query string which the user hasn't finished typing yet - as well as being less expense to evaluate than the full expansion, using only the most frequent terms tends to give better results too.
WILDCARD_LIMIT_MASK_
WILDCARD_PATTERN_MULTI	Support * which matches 0 or more characters. @since Added in Xapian 2.0.0
WILDCARD_PATTERN_SINGLE	Support ? which matches a single character. @since Added in Xapian 2.0.0.
WILDCARD_PATTERN_GLOB	Enable all supported glob-like features. @since Added in Xapian 2.0.0.

Definition at line 299 of file query.h.

◆ op

enum Xapian::Query::op

Query operators.

Enumerator
OP_AND	Match only documents which all subqueries match. When used in a weighted context, the weight is the sum of the weights for all the subqueries.
OP_OR	Match documents which at least one subquery matches. When used in a weighted context, the weight is the sum of the weights for matching subqueries (so additional matching subqueries will mean a higher weight).
OP_AND_NOT	Match documents which the first subquery matches but no others do. When used in a weighted context, the weight is just the weight of the first subquery.
OP_XOR	Match documents which an odd number of subqueries match. When used in a weighted context, the weight is the sum of the weights for matching subqueries (so additional matching subqueries will mean a higher weight).
OP_AND_MAYBE	Match the first subquery taking extra weight from other subqueries. When used in a weighted context, the weight is the sum of the weights for matching subqueries (so additional matching subqueries will mean a higher weight). Because only the first subquery determines which documents are matched, in a non-weighted context only the first subquery matters.
OP_FILTER	Match like OP_AND but only taking weight from the first subquery. When used in a non-weighted context, OP_FILTER and OP_AND are equivalent. In older 1.4.x, the third and subsequent subqueries were ignored in some situations. This was fixed in 1.4.15.
OP_NEAR	Match only documents where all subqueries match near each other. The subqueries must match at term positions within the specified window size, in any order. Currently subqueries must be terms or terms composed with OP_OR. When used in a weighted context, the weight is the sum of the weights for all the subqueries.
OP_PHRASE	Match only documents where all subqueries match near and in order. The subqueries must match at term positions within the specified window size, in the same term position order as subquery order. Currently subqueries must be terms or terms composed with OP_OR. When used in a weighted context, the weight is the sum of the weights for all the subqueries.
OP_VALUE_RANGE	Match only documents where a value slot is within a given range. This operator never contributes weight.
OP_SCALE_WEIGHT	Scale the weight contributed by a subquery. The weight is the weight of the subquery multiplied by the specified non-negative scale factor (so if the scale factor is zero then the subquery contributes no weight).
OP_ELITE_SET	Pick the best N subqueries and combine with OP_OR. If you want to implement a feature which finds documents similar to a piece of text, an obvious approach is to build an "OR" query from all the terms in the text, and run this query against a database containing the documents. However such a query can contain a lots of terms and be quite slow to perform, yet many of these terms don't contribute usefully to the results. The OP_ELITE_SET operator can be used instead of OP_OR in this situation. OP_ELITE_SET selects the most important ''N'' terms and then acts as an OP_OR query with just these, ignoring any other terms. This will usually return results just as good as the full OP_OR query, but much faster. In general, the OP_ELITE_SET operator can be used when you have a large OR query, but it doesn't matter if the search completely ignores some of the less important terms in the query. The subqueries don't have to be terms. If they aren't then OP_ELITE_SET could potentially pick a subset which doesn't actually match any documents even if the full OR would match some (because OP_ELITE_SET currently selects those subqueries which can return the highest weights). This is probably rare in practice though. You can specify a parameter to the query constructor which controls the number of subqueries which OP_ELITE_SET will pick. If not specified, this defaults to 10 (Xapian used to default to <code>ceil(sqrt(number_of_subqueries))</code> if there are more than 100 subqueries, but this rather arbitrary special case was dropped in 1.3.0). For example, this will pick the best 7 terms: <pre> Xapian::Query query(Xapian::Query::OP_ELITE_SET, subqs.begin(), subqs.end(), 7); </pre> If the number of subqueries is less than this threshold, OP_ELITE_SET behaves identically to OP_OR. When used with a sharded database, OP_ELITE_SET currently picks the subqueries to use separately for each shard based on the maximum weight they can return in that shard. This means it probably won't select exactly the same terms, and so the results of the search may not be exactly the same as for a single database with equivalent contents.
OP_VALUE_GE	Match only documents where a value slot is >= a given value. Similar to @a OP_VALUE_RANGE, but open-ended. This operator never contributes weight.
OP_VALUE_LE	Match only documents where a value slot is <= a given value. Similar to @a OP_VALUE_RANGE, but open-ended. This operator never contributes weight.
OP_SYNONYM	Match like OP_OR but weighting as if a single term. The weight is calculated combining the statistics for the subqueries to approximate the weight of a single term occurring with those statistics.
OP_MAX	Pick the maximum weight of any subquery. Matches the same documents as @a OP_OR, but the weight contributed is the maximum weight from any matching subquery (for OP_OR, it's the sum of the weights from the matching subqueries). @since Added in Xapian 1.3.2.
OP_WILDCARD	Wildcard expansion. @since Added in Xapian 1.3.3.
OP_EDIT_DISTANCE	Edit distance expansion. Expand to terms within a specified edit distance of a target. This works in a fairly similar way to OP_WILDCARD - the difference is that instead of expanding to terms matching a wildcard pattern, it expands to terms within a specified number of edits (insertion, deletion or substitution of a character, or transposition of two adjacent characters) of a specified target. @since Added in Xapian 2.0.0.
OP_INVALID	Construct an invalid query. This can be useful as a placeholder - for example @a RangeProcessor uses it as a return value to indicate that a range hasn't been recognised.
LEAF_TERM	Value returned by get_type() for a term.
LEAF_POSTING_SOURCE	Value returned by get_type() for a PostingSource.
LEAF_MATCH_ALL	Value returned by get_type() for MatchAll or equivalent. This is returned for any <code>Xapian::Query(std::string_view())</code> object.
LEAF_MATCH_NOTHING	Value returned by get_type() for MatchNothing or equivalent. This is returned for any <code>Xapian::Query()</code> object.

Definition at line 78 of file query.h.

Constructor & Destructor Documentation

◆ Query() [1/18]

Xapian::Query::Query ( )

inlinenoexcept

Construct a query matching no documents.

MatchNothing is a static instance of this.

When combined with other Query objects using the various supported operators, Query() works like false in boolean logic, so Query() & q is Query(), while Query() | q is q.

Definition at line 354 of file query.h.

Referenced by operator&=(), operator^=(), operator|=(), and unserialise().

◆ ~Query()

Xapian::Query::~Query ( )

inline

Destructor.

Definition at line 357 of file query.h.

Referenced by Query().

◆ Query() [2/18]

Xapian::Query::Query ( const Query & o )

inline

Copying is allowed.

The internals are reference counted, so copying is cheap.

Definition at line 363 of file query.h.

◆ Query() [3/18]

Xapian::Query::Query ( Query && )

default

Move constructor.

◆ Query() [4/18]

Xapian::Query::Query	(	const std::string &	term,
		Xapian::termcount	wqf = `1`,
		Xapian::termpos	pos = `0`
	)

inline

Construct a Query object for a term.

Parameters

term	The term. An empty string constructs a query matching all documents (MatchAll is a static instance of this).
wqf	The within-query frequency. (default: 1)
pos	The query position. Currently this is mainly used to determine the order of terms obtained via get_terms_begin(). (default: 0)

Definition at line 386 of file query.h.

◆ Query() [5/18]

Xapian::Query::Query	(	const char *	term,
		Xapian::termcount	wqf = `1`,
		Xapian::termpos	pos = `0`
	)

inline

Construct a Query object for a term.

Parameters

term	The term. An empty string constructs a query matching all documents (MatchAll is a static instance of this).
wqf	The within-query frequency. (default: 1)
pos	The query position. Currently this is mainly used to determine the order of terms obtained via get_terms_begin(). (default: 0)

Definition at line 401 of file query.h.

◆ Query() [6/18]

Xapian::Query::Query	(	std::string_view	term,
		Xapian::termcount	wqf = `1`,
		Xapian::termpos	pos = `0`
	)

Construct a Query object for a term.

Parameters

term	The term. An empty string constructs a query matching all documents (MatchAll is a static instance of this).
wqf	The within-query frequency. (default: 1)
pos	The query position. Currently this is mainly used to determine the order of terms obtained via get_terms_begin(). (default: 0)

Definition at line 43 of file query.cc.

References LOGCALL_CTOR, pos, and term.

◆ Query() [7/18]

Xapian::Query::Query ( Xapian::PostingSource * source )

explicit

Construct a Query object for a PostingSource.

Definition at line 49 of file query.cc.

References LOGCALL_CTOR.

◆ Query() [8/18]

Xapian::Query::Query	(	double	factor,
		const Xapian::Query &	subquery
	)

Scale using OP_SCALE_WEIGHT.

Parameters

factor	Non-negative real number to multiply weights by.
subquery	Query object to scale weights from.

Definition at line 55 of file query.cc.

References empty(), and LOGCALL_CTOR.

◆ Query() [9/18]

Xapian::Query::Query	(	op	op_,
		const Xapian::Query &	subquery,
		double	factor
	)

Scale using OP_SCALE_WEIGHT.

In this form, the op_ parameter is totally redundant - use Query(factor, subquery) in preference.

Parameters

op_	Must be OP_SCALE_WEIGHT.
factor	Non-negative real number to multiply weights by.
subquery	Query object to scale weights from.

Definition at line 63 of file query.cc.

References internal, LOGCALL_CTOR, OP_SCALE_WEIGHT, OP_VALUE_GE, OP_VALUE_LE, OP_VALUE_RANGE, and rare.

◆ Query() [10/18]

Xapian::Query::Query	(	op	op_,
		const Xapian::Query &	a,
		const Xapian::Query &	b
	)

inline

Construct a Query object by combining two others.

Parameters

op_	The operator to combine the queries with.
a	First subquery.
b	Second subquery.

Definition at line 447 of file query.h.

◆ Query() [11/18]

template<typename S1 , typename S2 , typename std::enable_if< std::is_constructible< std::string_view, S1 >::value &&std::is_constructible< std::string_view, S2 >::value, bool >::type = true>

Xapian::Query::Query	(	op	op_,
		S1	a,
		S2	b
	)

inline

Construct a Query object by combining two terms.

Parameters

op_	The operator to combine the terms with.
a	First term.
b	Second term.

Definition at line 467 of file query.h.

◆ Query() [12/18]

Xapian::Query::Query	(	op	op_,
		Xapian::valueno	slot,
		std::string_view	range_limit
	)

Construct a Query object for a single-ended value range.

Parameters

op_	Must be OP_VALUE_LE or OP_VALUE_GE currently.
slot	The value slot to work over.
range_limit	The limit of the range.

Definition at line 86 of file query.cc.

References LOGCALL_CTOR, OP_VALUE_GE, OP_VALUE_LE, and usual.

◆ Query() [13/18]

Xapian::Query::Query	(	op	op_,
		Xapian::valueno	slot,
		std::string_view	range_lower,
		std::string_view	range_upper
	)

Construct a Query object for a value range.

Parameters

op_	Must be OP_VALUE_RANGE currently.
slot	The value slot to work over.
range_lower	Lower end of the range.
range_upper	Upper end of the range.

Definition at line 102 of file query.cc.

References LOGCALL_CTOR, OP_VALUE_RANGE, rare, and usual.

◆ Query() [14/18]

Xapian::Query::Query	(	op	op_,
		std::string_view	pattern,
		Xapian::termcount	max_expansion = `0`,
		int	flags = `WILDCARD_LIMIT_ERROR`,
		op	combiner = `OP_SYNONYM`
	)

Query constructor for OP_EDIT_DISTANCE and OP_WILDCARD queries.

Parameters

op_	Must be OP_EDIT_DISTANCE or OP_WILDCARD
pattern	The wildcard pattern (for OP_WILDCARD) or target string (for OP_EDIT_DISTANCE). See flags which affects how this pattern is interpreted.
max_expansion	The maximum number of terms to expand to (default: 0, which means no limit)
flags	Flags controlling aspects of the wildcarding - this consists of a bitwise OR of:

At most one of WILDCARD_LIMIT_ERROR (the default), WILDCARD_LIMIT_FIRST or WILDCARD_LIMIT_MOST_FREQUENT specifying how to enforce max_expansion.

When searching multiple databases, the expansion limit is currently applied independently for each database, so the total number of terms may be higher than the limit. This is arguably a bug, and may change in future versions.
For OP_WILDCARD: Zero or more of WILDCARD_PATTERN_MULTI and WILDCARD_PATTERN_SINGLE, which specify whether '*' (matching zero or more characters) and '?' (matching exactly one character) are supported. If neither is specified, then a Xapian-1.4-compatible mode is used where the pattern matches terms which start with the pattern interpreted as a literal string.

Parameters

combiner The Query::op to combine the terms with - one of OP_SYNONYM (the default), OP_OR or OP_MAX.

For OP_WILDCARD: A leading wildcard won't match terms starting with an ASCII capital letter, as this is assumed to be part of a term prefix.

Definition at line 117 of file query.cc.

References LOGCALL_CTOR, OP_EDIT_DISTANCE, OP_MAX, OP_OR, OP_SYNONYM, OP_WILDCARD, rare, WILDCARD_LIMIT_MASK_, WILDCARD_PATTERN_MULTI, WILDCARD_PATTERN_SINGLE, and ~Query().

◆ Query() [15/18]

Xapian::Query::Query	(	op	op_,
		std::string_view	pattern,
		Xapian::termcount	max_expansion,
		int	flags,
		op	combiner,
		unsigned	edit_distance,
		size_t	min_prefix_len = `0`
	)

Query constructor for OP_EDIT_DISTANCE queries.

This form supports some additional parameters.

Parameters

op_	Must be OP_EDIT_DISTANCE.
pattern	The target string.
max_expansion	The maximum number of terms to expand to (default: 0, which means no limit)
flags	Flags controlling aspects of the wildcarding: * At most one of @a WILDCARD_LIMIT_ERROR (the default), @a WILDCARD_LIMIT_FIRST or @a WILDCARD_LIMIT_MOST_FREQUENT specifying how to enforce max_expansion. When searching multiple databases, the expansion limit is currently applied independently for each database, so the total number of terms may be higher than the limit. This is arguably a bug, and may change in future versions.
combiner	The Query::op to combine the terms with - one of OP_SYNONYM (the default), OP_OR or OP_MAX.
edit_distance	The maximum number of edits allowed between a term and target (an edit is insertion, deletion or substitution of a character, or transposition of two adjacent characters). Default: 2
min_prefix_len	The length in bytes of any initial substring of target that is required to match exactly. Default: 0

Since: Added in Xapian 2.0.0.

Definition at line 175 of file query.cc.

References LOGCALL_CTOR, OP_EDIT_DISTANCE, OP_MAX, OP_OR, OP_SYNONYM, and rare.

◆ Query() [16/18]

template<typename I , typename std::enable_if< std::is_convertible< typename std::iterator_traits< I >::value_type, Xapian::Query >::value||std::is_convertible< typename std::iterator_traits< I >::value_type, Xapian::Query * >::value||std::is_convertible< typename std::iterator_traits< I >::value_type, std::string_view >::value, bool >::type = true, typename iterator_category = typename std::iterator_traits<I>::iterator_category>

Xapian::Query::Query	(	op	op_,
		I	begin,
		I	end,
		Xapian::termcount	window = `0`
	)

inline

Construct a Query object from a begin/end iterator pair.

Dereferencing the iterator should return a Xapian::Query, a non-NULL Xapian::Query*, a std::string_view or a type which converts to one of these (e.g. std::string or const char*).

If begin == end then there are no subqueries and the resulting Query won't match anything.

Parameters

op_	The operator to combine the queries with.
begin	Begin iterator.
end	End iterator.
window	Window size for OP_NEAR and OP_PHRASE, or 0 to use the number of subqueries as the window size (default: 0).

Definition at line 605 of file query.h.

◆ Query() [17/18]

Xapian::Query::Query ( Internal * internal_ )

inlineexplicitprivate

Wrap an existing Internal.

Definition at line 750 of file query.h.

◆ Query() [18/18]

Xapian::Query::Query ( Query::op op_ )

inlineexplicit

Construct with just an operator.

Parameters

op_	The operator to use - currently only OP_INVALID is useful.

Definition at line 756 of file query.h.

References OP_INVALID.

Member Function Documentation

◆ add_subquery() [1/5]

void Xapian::Query::add_subquery	(	bool	positional,
		const Xapian::Query &	subquery
	)

private

Definition at line 371 of file query.cc.

References Xapian::Internal::QueryBranch::add_subquery(), Assert, get_type(), LEAF_MATCH_ALL, LEAF_MATCH_NOTHING, LEAF_POSTING_SOURCE, LEAF_TERM, MatchNothing, and OP_OR.

Referenced by operator&=(), operator^=(), and operator|=().

◆ add_subquery() [2/5]

void Xapian::Query::add_subquery	(	bool	positional,
		const Xapian::Query *	subquery
	)

inlineprivate

Definition at line 792 of file query.h.

◆ add_subquery() [3/5]

void Xapian::Query::add_subquery	(	bool	,
		const char *	subquery
	)

inlineprivate

Definition at line 784 of file query.h.

◆ add_subquery() [4/5]

void Xapian::Query::add_subquery	(	bool	,
		const std::string &	subquery
	)

inlineprivate

Definition at line 780 of file query.h.

◆ add_subquery() [5/5]

void Xapian::Query::add_subquery	(	bool	,
		std::string_view	subquery
	)

inlineprivate

Definition at line 788 of file query.h.

◆ done()

void Xapian::Query::done ( )

private

Definition at line 403 of file query.cc.

References Xapian::Internal::QueryBranch::done().

◆ empty()

bool Xapian::Query::empty ( ) const

inlinenoexcept

Check if this query is Xapian::Query::MatchNothing.

Definition at line 661 of file query.h.

Referenced by DEFINE_TESTCASE(), Xapian::Internal::Context::expand_wildcard(), Xapian::Enquire::get_description(), Xapian::Enquire::Internal::get_eset(), Xapian::Enquire::Internal::get_matching_terms_begin(), Xapian::Enquire::Internal::get_mset(), LocalSubMatch::get_postlist(), operator^=(), operator|=(), Query(), and yy_reduce().

◆ get_description()

string Xapian::Query::get_description ( ) const

Return a string describing this object.

Definition at line 307 of file query.cc.

Referenced by DEFINE_TESTCASE(), main(), and PerfTestLogger::search_end().

◆ get_leaf_pos()

Xapian::termpos Xapian::Query::get_leaf_pos ( ) const

Get the pos parameter of a leaf node.

Since: Added in Xapian 2.0.0.

Definition at line 301 of file query.cc.

Referenced by DEFINE_TESTCASE().

◆ get_leaf_wqf()

Xapian::termcount Xapian::Query::get_leaf_wqf ( ) const

Get the wqf parameter of a leaf node.

Since: Added in Xapian 2.0.0.

Definition at line 295 of file query.cc.

Referenced by DEFINE_TESTCASE().

◆ get_length()

Xapian::termcount Xapian::Query::get_length ( ) const

noexcept

Return the length of this query object.

Definition at line 250 of file query.cc.

References internal.

Referenced by DEFINE_TESTCASE(), and Xapian::Enquire::Internal::get_mset().

◆ get_num_subqueries()

size_t Xapian::Query::get_num_subqueries ( ) const

noexcept

Get the number of subqueries of the top level query.

Definition at line 283 of file query.cc.

Referenced by Xapian::check_query(), and DEFINE_TESTCASE().

◆ get_subquery()

const Query Xapian::Query::get_subquery ( size_t n ) const

Read a top level subquery.

Parameters

n	Return the n-th subquery (starting from 0) - only valid when 0 <= n < get_num_subqueries().

Definition at line 289 of file query.cc.

References get_subquery().

Referenced by Xapian::Internal::QueryAndNot::add_subquery(), Xapian::check_query(), DEFINE_TESTCASE(), and get_subquery().

◆ get_terms_begin()

const TermIterator Xapian::Query::get_terms_begin ( ) const

Begin iterator for terms in the query object.

The iterator returns terms in ascending query position order, and will return the same term in each unique position it occurs in. If you want the terms in sorted order and without duplicates, see get_unique_terms_begin().

Definition at line 198 of file query.cc.

References Heap::sort().

Referenced by DEFINE_TESTCASE(), Xapian::Enquire::Internal::get_eset(), Xapian::Enquire::Internal::get_matching_terms_begin(), and main().

◆ get_terms_end()

const TermIterator Xapian::Query::get_terms_end ( ) const

inlinenoexcept

End iterator for terms in the query object.

Definition at line 639 of file query.h.

Referenced by DEFINE_TESTCASE(), Xapian::Enquire::Internal::get_eset(), Xapian::Enquire::Internal::get_matching_terms_begin(), and main().

◆ get_type()

Xapian::Query::op Xapian::Query::get_type ( ) const

noexcept

Get the type of the top level of the query.

Definition at line 275 of file query.cc.

References LEAF_MATCH_NOTHING.

Referenced by add_subquery(), Xapian::Internal::QueryAndNot::add_subquery(), Terms::as_opwindow_query(), Xapian::check_query(), DEFINE_TESTCASE(), and State::range().

◆ get_unique_terms_begin()

const TermIterator Xapian::Query::get_unique_terms_begin ( ) const

Begin iterator for unique terms in the query object.

Terms are sorted and terms with the same name removed from the list.

If you want the terms in ascending query position order, see get_terms_begin().

Definition at line 223 of file query.cc.

References Heap::sort().

Referenced by Xapian::Weight::Internal::accumulate_stats(), DEFINE_TESTCASE(), and GlassDatabase::readahead_for_query().

◆ get_unique_terms_end()

const TermIterator Xapian::Query::get_unique_terms_end ( ) const

inlinenoexcept

End iterator for unique terms in the query object.

Definition at line 653 of file query.h.

Referenced by DEFINE_TESTCASE().

◆ init() [1/3]

void Xapian::Query::init	(	Query::op	op_,
		size_t	n_subqueries,
		Xapian::termcount	window = `0`
	)

private

Definition at line 317 of file query.cc.

References OP_AND, OP_AND_MAYBE, OP_AND_NOT, OP_ELITE_SET, OP_FILTER, OP_INVALID, OP_MAX, OP_NEAR, OP_OR, OP_PHRASE, OP_SYNONYM, and OP_XOR.

◆ init() [2/3]

template<typename I >

void Xapian::Query::init	(	Query::op	op_,
		Xapian::termcount	window,
		const I &	,
		const I &	,
		std::input_iterator_tag
	)

inlineprivate

Definition at line 772 of file query.h.

◆ init() [3/3]

template<typename I >

void Xapian::Query::init	(	Query::op	op_,
		Xapian::termcount	window,
		const I &	begin,
		const I &	end,
		std::random_access_iterator_tag
	)

inlineprivate

Definition at line 765 of file query.h.

◆ operator&=()

const Query Xapian::Query::operator&= ( const Query & o )

inline

Combine with another Xapian::Query object using OP_AND.

Since: Since Xapian 1.4.10, when called on a Query object which is OP_AND and has a reference count of 1, then o is appended as a new subquery (provided o is a different Query object and !o.empty()).

Definition at line 987 of file query.h.

References add_subquery(), Xapian::Query::Internal::get_type(), internal, OP_AND, and Query().

◆ operator*=()

const Query Xapian::Query::operator*= ( double factor )

inline

Scale using OP_SCALE_WEIGHT.

Parameters

factor Non-negative real number to multiply weights by.

Definition at line 737 of file query.h.

◆ operator/=()

const Query Xapian::Query::operator/= ( double factor )

inline

Inverse scale using OP_SCALE_WEIGHT.

Parameters

factor Positive real number to divide weights by.

Definition at line 745 of file query.h.

◆ operator=() [1/2]

Query& Xapian::Query::operator= ( const Query & o )

inline

Copying is allowed.

The internals are reference counted, so assignment is cheap.

Definition at line 369 of file query.h.

References internal.

◆ operator=() [2/2]

Query& Xapian::Query::operator= ( Query && )

default

Move assignment operator.

◆ operator^=()

const Query Xapian::Query::operator^= ( const Query & o )

inline

Combine with another Xapian::Query object using OP_XOR.

Since: Since Xapian 1.4.10, when called on a Query object which is OP_XOR and has a reference count of 1, then o is appended as a new subquery (provided o is a different Query object and !o.empty()).

Definition at line 1022 of file query.h.

References add_subquery(), empty(), Xapian::Query::Internal::get_type(), internal, OP_XOR, and Query().

◆ operator|=()

const Query Xapian::Query::operator|= ( const Query & o )

inline

Combine with another Xapian::Query object using OP_OR.

Since: Since Xapian 1.4.10, when called on a Query object which is OP_OR and has a reference count of 1, then o is appended as a new subquery (provided o is a different Query object and !o.empty()).

Definition at line 1005 of file query.h.

References add_subquery(), empty(), Xapian::Query::Internal::get_type(), internal, OP_OR, and Query().

◆ serialise()

string Xapian::Query::serialise ( ) const

Serialise this object into a string.

Definition at line 256 of file query.cc.

Referenced by DEFINE_TESTCASE(), and RemoteDatabase::set_query().

◆ unserialise()

const Query Xapian::Query::unserialise	(	std::string_view	serialised,
		const Registry &	reg = `Registry()`
	)

static

Unserialise a string and return a Query object.

Parameters

serialised	the string to unserialise.
reg	Xapian::Registry object to use to unserialise user-subclasses of Xapian::PostingSource (default: standard registry).

Definition at line 265 of file query.cc.

References AssertEq, p, Query(), and Xapian::Query::Internal::unserialise().

Referenced by DEFINE_TESTCASE(), and RemoteServer::msg_query().

Member Data Documentation

◆ internal

Xapian::Internal::intrusive_ptr<Internal> Xapian::Query::internal

private

◆ MatchAll

const Query Xapian::Query::MatchAll

static

A query matching all documents.

This is a static instance of Xapian::Query(std::string_view()). If you are constructing Query objects which use MatchAll in different threads then the reference counting of the static object can get messed up by concurrent access so you should instead use Xapian::Query(std::string_view()) directly.

Definition at line 75 of file query.h.

Referenced by DEFINE_TESTCASE(), TestRangeProcessor::operator()(), TitleFieldProcessor::operator()(), and HostFieldProcessor::operator()().

◆ MatchNothing

const Query Xapian::Query::MatchNothing

static

A query matching no documents.

This is a static instance of a default-constructed Xapian::Query object. It is safe to use concurrently from different threads, unlike MatchAll (this is because MatchNothing has a NULL internal object so there's no reference counting happening).

When combined with other Query objects using the various supported operators, MatchNothing works like false in boolean logic, so MatchNothing & q is MatchNothing, while MatchNothing | q is q.

Definition at line 64 of file query.h.

Referenced by add_subquery(), and DEFINE_TESTCASE().

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

include/xapian/query.h
api/query.cc

Classes

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Private Member Functions

Private Attributes

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

◆ op

Constructor & Destructor Documentation

◆ Query() [1/18]

◆ ~Query()

◆ Query() [2/18]

◆ Query() [3/18]

◆ Query() [4/18]

◆ Query() [5/18]

◆ Query() [6/18]

◆ Query() [7/18]

◆ Query() [8/18]

◆ Query() [9/18]

◆ Query() [10/18]

◆ Query() [11/18]

◆ Query() [12/18]

◆ Query() [13/18]

◆ Query() [14/18]

◆ Query() [15/18]

◆ Query() [16/18]

◆ Query() [17/18]

◆ Query() [18/18]

Member Function Documentation

◆ add_subquery() [1/5]

◆ add_subquery() [2/5]

◆ add_subquery() [3/5]

◆ add_subquery() [4/5]

◆ add_subquery() [5/5]

◆ done()

◆ empty()

◆ get_description()

◆ get_leaf_pos()

◆ get_leaf_wqf()

◆ get_length()

◆ get_num_subqueries()

◆ get_subquery()

◆ get_terms_begin()

◆ get_terms_end()

◆ get_type()

◆ get_unique_terms_begin()

◆ get_unique_terms_end()

◆ init() [1/3]

◆ init() [2/3]

◆ init() [3/3]

◆ operator&=()

◆ operator*=()

◆ operator/=()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator^=()

◆ operator|=()

◆ serialise()

◆ unserialise()

Member Data Documentation

◆ internal

◆ MatchAll

◆ MatchNothing