Resource class for MDB_dbi handles. More...

#include <lmdb++.h>

Public Member Functions
	dbi (const MDB_dbi handle) noexcept
	Constructor.
	dbi (dbi &&other) noexcept
	Move constructor.
dbi &	operator= (dbi &&other) noexcept
	Move assignment operator.
	~dbi () noexcept
	Destructor.
	operator MDB_dbi () const noexcept
	Returns the underlying MDB_dbi handle.
MDB_dbi	handle () const noexcept
	Returns the underlying MDB_dbi handle.
MDB_stat	stat (MDB_txn *const txn) const
	Returns statistics for this database.
unsigned int	flags (MDB_txn *const txn) const
	Retrieves the flags for this database handle.
std::size_t	size (MDB_txn *const txn) const
	Returns the number of records in this database.
void	drop (MDB_txn *const txn, const bool del=false)
dbi &	set_compare (MDB_txn const txn, MDB_cmp_func const cmp=nullptr)
	Sets a custom key comparison function for this database.
bool	get (MDB_txn *const txn, const val &key, val &data)
	Retrieves a key/value pair from this database.
template<typename K>
bool	get (MDB_txn *const txn, const K &key) const
	Retrieves a key from this database.
template<typename K, typename V>
bool	get (MDB_txn *const txn, const K &key, V &val) const
	Retrieves a key/value pair from this database.
template<typename V>
bool	get (MDB_txn const txn, const char const key, V &val) const
	Retrieves a key/value pair from this database.
bool	put (MDB_txn *const txn, const val &key, val &data, const unsigned int flags=default_put_flags)
	Stores a key/value pair into this database.
template<typename K>
bool	put (MDB_txn *const txn, const K &key, const unsigned int flags=default_put_flags)
	Stores a key into this database.
template<typename K, typename V>
bool	put (MDB_txn *const txn, const K &key, const V &val, const unsigned int flags=default_put_flags)
	Stores a key/value pair into this database.
template<typename V>
bool	put (MDB_txn const txn, const char const key, const V &val, const unsigned int flags=default_put_flags)
	Stores a key/value pair into this database.
bool	put (MDB_txn const txn, const char const key, const char *const val, const unsigned int flags=default_put_flags)
	Stores a key/value pair into this database.
bool	del (MDB_txn *const txn, const val &key)
	Removes a key/value pair from this database.
template<typename K>
bool	del (MDB_txn *const txn, const K &key)
	Removes a key/value pair from this database.

Static Public Member Functions
static dbi	open (MDB_txn const txn, const char const name=nullptr, const unsigned int flags=default_flags)
	Opens a database handle.

Static Public Attributes
static constexpr unsigned int	default_flags = 0
static constexpr unsigned int	default_put_flags = 0

Protected Attributes
MDB_dbi	_handle {0}

Detailed Description

Resource class for MDB_dbi handles.

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

See also: http://symas.com/mdb/doc/group__mdb.html#gadbe68a06c448dfb62da16443d251a78b

Constructor & Destructor Documentation

◆ dbi() [1/2]

lmdb::dbi::dbi ( const MDB_dbi handle )

inlinenoexcept

Constructor.

Parameters

handle a valid MDB_dbi handle

◆ dbi() [2/2]

lmdb::dbi::dbi ( dbi && other )

inlinenoexcept

Move constructor.

◆ ~dbi()

lmdb::dbi::~dbi ( )

inlinenoexcept

Destructor.

Member Function Documentation

◆ del() [1/2]

template<typename K>

bool lmdb::dbi::del	(	MDB_txn *const	txn,
		const K &	key )

inline

Removes a key/value pair from this database.

Parameters

txn	a transaction handle
key

Exceptions

lmdb::error on failure

◆ del() [2/2]

bool lmdb::dbi::del	(	MDB_txn *const	txn,
		const val &	key )

inline

Removes a key/value pair from this database.

Parameters

txn	a transaction handle
key

Exceptions

lmdb::error on failure

◆ drop()

void lmdb::dbi::drop	(	MDB_txn *const	txn,
		const bool	del = false )

inline

Parameters

txn	a transaction handle
del

Exceptions

lmdb::error on failure

◆ flags()

unsigned int lmdb::dbi::flags ( MDB_txn *const txn ) const

inline

Retrieves the flags for this database handle.

Parameters

txn	a transaction handle

Exceptions

lmdb::error on failure

◆ get() [1/4]

template<typename V>

bool lmdb::dbi::get	(	MDB_txn *const	txn,
		const char *const	key,
		V &	val ) const

inline

Retrieves a key/value pair from this database.

Parameters

txn	a transaction handle
key	a NUL-terminated string key
val

Exceptions

lmdb::error on failure

◆ get() [2/4]

template<typename K>

bool lmdb::dbi::get	(	MDB_txn *const	txn,
		const K &	key ) const

inline

Retrieves a key from this database.

Parameters

txn	a transaction handle
key

Exceptions

lmdb::error on failure

◆ get() [3/4]

template<typename K, typename V>

bool lmdb::dbi::get	(	MDB_txn *const	txn,
		const K &	key,
		V &	val ) const

inline

Retrieves a key/value pair from this database.

Parameters

txn	a transaction handle
key
val

Exceptions

lmdb::error on failure

◆ get() [4/4]

bool lmdb::dbi::get	(	MDB_txn *const	txn,
		const val &	key,
		val &	data )

inline

Retrieves a key/value pair from this database.

Parameters

txn	a transaction handle
key
data

Exceptions

lmdb::error on failure

◆ handle()

MDB_dbi lmdb::dbi::handle ( ) const

inlinenoexcept

Returns the underlying MDB_dbi handle.

◆ open()

dbi lmdb::dbi::open	(	MDB_txn *const	txn,
		const char *const	name = nullptr,
		const unsigned int	flags = default_flags )

inlinestatic

Opens a database handle.

Parameters

txn	the transaction handle
name
flags

Exceptions

lmdb::error on failure

◆ operator MDB_dbi()

lmdb::dbi::operator MDB_dbi ( ) const

inlinenoexcept

Returns the underlying MDB_dbi handle.

◆ operator=()

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

inlinenoexcept

Move assignment operator.

◆ put() [1/5]

bool lmdb::dbi::put	(	MDB_txn *const	txn,
		const char *const	key,
		const char *const	val,
		const unsigned int	flags = default_put_flags )

inline

Stores a key/value pair into this database.

Parameters

txn	a transaction handle
key	a NUL-terminated string key
val	a NUL-terminated string key
flags

Exceptions

lmdb::error on failure

◆ put() [2/5]

template<typename V>

bool lmdb::dbi::put	(	MDB_txn *const	txn,
		const char *const	key,
		const V &	val,
		const unsigned int	flags = default_put_flags )

inline

Stores a key/value pair into this database.

Parameters

txn	a transaction handle
key	a NUL-terminated string key
val
flags

Exceptions

lmdb::error on failure

◆ put() [3/5]

template<typename K>

bool lmdb::dbi::put	(	MDB_txn *const	txn,
		const K &	key,
		const unsigned int	flags = default_put_flags )

inline

Stores a key into this database.

Parameters

txn	a transaction handle
key
flags

Exceptions

lmdb::error on failure

◆ put() [4/5]

template<typename K, typename V>

bool lmdb::dbi::put	(	MDB_txn *const	txn,
		const K &	key,
		const V &	val,
		const unsigned int	flags = default_put_flags )

inline

Stores a key/value pair into this database.

Parameters

txn	a transaction handle
key
val
flags

Exceptions

lmdb::error on failure

◆ put() [5/5]

bool lmdb::dbi::put	(	MDB_txn *const	txn,
		const val &	key,
		val &	data,
		const unsigned int	flags = default_put_flags )

inline

Stores a key/value pair into this database.

Parameters

txn	a transaction handle
key
data
flags

Exceptions

lmdb::error on failure

◆ set_compare()

dbi & lmdb::dbi::set_compare	(	MDB_txn *const	txn,
		MDB_cmp_func *const	cmp = nullptr )

inline

Sets a custom key comparison function for this database.

Parameters

txn	a transaction handle
cmp	the comparison function

Exceptions

lmdb::error on failure

◆ size()

std::size_t lmdb::dbi::size ( MDB_txn *const txn ) const

inline

Returns the number of records in this database.

Parameters

txn	a transaction handle

Exceptions

lmdb::error on failure

◆ stat()

MDB_stat lmdb::dbi::stat ( MDB_txn *const txn ) const

inline

Returns statistics for this database.

Parameters

txn	a transaction handle

Exceptions

lmdb::error on failure

Member Data Documentation

◆ _handle

MDB_dbi lmdb::dbi::_handle {0}

protected

◆ default_flags

unsigned int lmdb::dbi::default_flags = 0

staticconstexpr

◆ default_put_flags

unsigned int lmdb::dbi::default_put_flags = 0

staticconstexpr

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

◆ dbi() [1/2]

◆ dbi() [2/2]

◆ ~dbi()

Member Function Documentation

◆ del() [1/2]

◆ del() [2/2]

◆ drop()

◆ flags()

◆ get() [1/4]

◆ get() [2/4]

◆ get() [3/4]

◆ get() [4/4]

◆ handle()

◆ open()

◆ operator MDB_dbi()

◆ operator=()

◆ put() [1/5]

◆ put() [2/5]

◆ put() [3/5]

◆ put() [4/5]

◆ put() [5/5]

◆ set_compare()

◆ size()

◆ stat()

Member Data Documentation

◆ _handle

◆ default_flags

◆ default_put_flags