#include <mongocxx/v_noabi/mongocxx/read_concern.hpp>

Description

Controls the consistency and isolation properties of data read from replica sets and sharded clusters.

Read concern can be set at the client, database, or collection level. The read concern can also be provided via connection string, and will be parsed and set on the client constructed for the URI.

See also

Read Concern (MongoDB Manual)

Public Types
enum class	level
	A class to represent the read concern level for read operations. More...

Public Member Functions
	read_concern ()
	Constructs a new read_concern with default acknowledge_level of k_server_default.

	read_concern (read_concern &&) noexcept
	Move constructs a read_concern.

	read_concern (read_concern const &)
	Copy constructs a read_concern.

	~read_concern ()
	Destroys a read_concern.

level	acknowledge_level () const
	Gets the current read concern level.

void	acknowledge_level (level rc_level)
	Sets the read concern level.

bsoncxx::v_noabi::stdx::string_view	acknowledge_string () const
	Gets the current read concern string.

void	acknowledge_string (bsoncxx::v_noabi::stdx::string_view rc_string)
	Sets the read concern string. Any valid read concern string (e.g. "local", "majority", "linearizable", "") may be passed in. For forward-compatibility with read concern levels introduced in the future, no validation is performed on this string.

read_concern &	operator= (read_concern &&) noexcept
	Move assigns a read_concern.

read_concern &	operator= (read_concern const &)
	Copy assigns a read_concern.

bsoncxx::v_noabi::document::value	to_document () const
	Gets the document form of this read_concern.

Related Symbols
(Note that these are not member symbols.)

bool	operator== (read_concern const &, read_concern const &)
	Compares two read_concern objects for (in)-equality.

bool	operator!= (read_concern const &, read_concern const &)
	Compares two read_concern objects for (in)-equality.

Member Enumeration Documentation

◆ level

enum class mongocxx::v_noabi::read_concern::level

strong

A class to represent the read concern level for read operations.

See also

Enumerator
k_local	Represent read concern level "local".
k_majority	Represent read concern level "majority".
k_linearizable	Represent read concern level "linearizable".
k_server_default	Represent the server's default read concern level.
k_unknown	Represent an unknown read concern level.
k_available	Represent read concern level "available".
k_snapshot	Represent read concern level "snapshot".

Constructor & Destructor Documentation

◆ read_concern() [1/3]

mongocxx::v_noabi::read_concern::read_concern ( )

Constructs a new read_concern with default acknowledge_level of k_server_default.

The k_server_default acknowledge level has an empty acknowledge_string. Queries that run with this read_concern will use the server's default read_concern instead of specifying one.

◆ read_concern() [2/3]

mongocxx::v_noabi::read_concern::read_concern ( read_concern const & )

Copy constructs a read_concern.

◆ read_concern() [3/3]

mongocxx::v_noabi::read_concern::read_concern ( read_concern && )

noexcept

Move constructs a read_concern.

◆ ~read_concern()

mongocxx::v_noabi::read_concern::~read_concern ( )

Destroys a read_concern.

Member Function Documentation

◆ acknowledge_level() [1/2]

level mongocxx::v_noabi::read_concern::acknowledge_level ( ) const

Gets the current read concern level.

If this was set with acknowledge_string to anything other than "local", "majority", "linearizable", or an empty string, this will return k_unknown.

Returns: The read concern level.

◆ acknowledge_level() [2/2]

void mongocxx::v_noabi::read_concern::acknowledge_level ( level rc_level )

Sets the read concern level.

Parameters

rc_level Either k_local, k_majority, k_linearizable, or k_server_default.

Exceptions

mongocxx::v_noabi::exception if rc_level is not k_local, k_majority, k_linearizable, or k_server_default.

◆ acknowledge_string() [1/2]

bsoncxx::v_noabi::stdx::string_view mongocxx::v_noabi::read_concern::acknowledge_string ( ) const

Gets the current read concern string.

If the read concern level was set with acknowledge_level, this will return either "local", "majority", "linearizable", or an empty string for k_server_default.

Returns: The read concern string.

◆ acknowledge_string() [2/2]

void mongocxx::v_noabi::read_concern::acknowledge_string ( bsoncxx::v_noabi::stdx::string_view rc_string )

Sets the read concern string. Any valid read concern string (e.g. "local", "majority", "linearizable", "") may be passed in. For forward-compatibility with read concern levels introduced in the future, no validation is performed on this string.

Parameters

rc_string The read concern string.

◆ operator=() [1/2]

read_concern & mongocxx::v_noabi::read_concern::operator= ( read_concern && )

noexcept

Move assigns a read_concern.

◆ operator=() [2/2]

read_concern & mongocxx::v_noabi::read_concern::operator= ( read_concern const & )

Copy assigns a read_concern.

◆ to_document()

bsoncxx::v_noabi::document::value mongocxx::v_noabi::read_concern::to_document ( ) const

Gets the document form of this read_concern.

Returns: Document representation of this read_concern.

Friends And Related Symbol Documentation

◆ operator!=

bool operator!=	(	read_concern const &	,
		read_concern const &	)

friend

Compares two read_concern objects for (in)-equality.

◆ operator==

bool operator==	(	read_concern const &	,
		read_concern const &	)