Resource class for MDB_cursor* handles. More...

#include <lmdb++.h>

Public Member Functions
	cursor (MDB_cursor *const handle) noexcept
	Constructor. More...

	cursor (cursor &&other) noexcept
	Move constructor. More...

cursor &	operator= (cursor &&other) noexcept
	Move assignment operator. More...

	~cursor () noexcept
	Destructor. More...

	operator MDB_cursor * () const noexcept
	Returns the underlying `MDB_cursor*` handle. More...

MDB_cursor *	handle () const noexcept
	Returns the underlying `MDB_cursor*` handle. More...

void	close () noexcept
	Closes this cursor. More...

void	renew (MDB_txn *const txn)
	Renews this cursor. More...

MDB_txn *	txn () const noexcept
	Returns the cursor's transaction handle. More...

MDB_dbi	dbi () const noexcept
	Returns the cursor's database handle. More...

bool	get (MDB_val *const key, const MDB_cursor_op op)
	Retrieves a key from the database. More...

bool	get (lmdb::val &key, const MDB_cursor_op op)
	Retrieves a key from the database. More...

bool	get (MDB_val const key, MDB_val const val, const MDB_cursor_op op)
	Retrieves a key/value pair from the database. More...

bool	get (lmdb::val &key, lmdb::val &val, const MDB_cursor_op op)
	Retrieves a key/value pair from the database. More...

bool	get (std::string &key, std::string &val, const MDB_cursor_op op)
	Retrieves a key/value pair from the database. More...

template<typename K >
bool	find (const K &key, const MDB_cursor_op op=MDB_SET)
	Positions this cursor at the given key. More...

Static Public Member Functions
static cursor	open (MDB_txn *const txn, const MDB_dbi dbi)
	Creates an LMDB cursor. More...

Static Public Attributes
static constexpr unsigned int	default_flags = 0

Protected Attributes
MDB_cursor *	_handle {nullptr}

Detailed Description

Resource class for MDB_cursor* handles.

Note: Instances of this class are movable, but not copyable.

See also: http://symas.com/mdb/doc/group__internal.html#structMDB__cursor

Constructor & Destructor Documentation

lmdb::cursor::cursor ( MDB_cursor *const handle )

inlinenoexcept

Constructor.

Parameters

handle a valid MDB_cursor* handle

lmdb::cursor::cursor ( cursor && other )

inlinenoexcept

Move constructor.

lmdb::cursor::~cursor ( )

inlinenoexcept

Destructor.

Member Function Documentation

void lmdb::cursor::close ( )

inlinenoexcept

Closes this cursor.

Note: this method is idempotent

Postcondition: handle() == nullptr

MDB_dbi lmdb::cursor::dbi ( ) const

inlinenoexcept

Returns the cursor's database handle.

template<typename K >

bool lmdb::cursor::find	(	const K &	key,
		const MDB_cursor_op	op = `MDB_SET`
	)

inline

Positions this cursor at the given key.

Parameters

key
op

Exceptions

lmdb::error on failure

bool lmdb::cursor::get	(	MDB_val *const	key,
		const MDB_cursor_op	op
	)

inline

Retrieves a key from the database.

Parameters

key
op

Exceptions

lmdb::error on failure

bool lmdb::cursor::get	(	lmdb::val &	key,
		const MDB_cursor_op	op
	)

inline

Retrieves a key from the database.

Parameters

key
op

Exceptions

lmdb::error on failure

bool lmdb::cursor::get	(	MDB_val *const	key,
		MDB_val *const	val,
		const MDB_cursor_op	op
	)

inline

Retrieves a key/value pair from the database.

Parameters

key
val	(may be `nullptr`)
op

Exceptions

lmdb::error on failure

bool lmdb::cursor::get	(	lmdb::val &	key,
		lmdb::val &	val,
		const MDB_cursor_op	op
	)

inline

Retrieves a key/value pair from the database.

Parameters

key
val
op

Exceptions

lmdb::error on failure

bool lmdb::cursor::get	(	std::string &	key,
		std::string &	val,
		const MDB_cursor_op	op
	)

inline

Retrieves a key/value pair from the database.

Parameters

key
val
op

Exceptions

lmdb::error on failure

MDB_cursor* lmdb::cursor::handle ( ) const

inlinenoexcept

Returns the underlying MDB_cursor* handle.

static cursor lmdb::cursor::open	(	MDB_txn *const	txn,
		const MDB_dbi	dbi
	)

inlinestatic

Creates an LMDB cursor.

Parameters

txn	the transaction handle
dbi	the database handle

Exceptions

lmdb::error on failure

lmdb::cursor::operator MDB_cursor * ( ) const

inlinenoexcept

Returns the underlying MDB_cursor* handle.

cursor& lmdb::cursor::operator= ( cursor && other )

inlinenoexcept

Move assignment operator.

void lmdb::cursor::renew ( MDB_txn *const txn )

inline

Renews this cursor.

Parameters

txn	the transaction scope

Exceptions

lmdb::error on failure

MDB_txn* lmdb::cursor::txn ( ) const

inlinenoexcept

Returns the cursor's transaction handle.

Member Data Documentation

MDB_cursor* lmdb::cursor::_handle {nullptr}

protected

constexpr unsigned int lmdb::cursor::default_flags = 0

static

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

lmdb++.h

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation