lmdb::key_stream< K, V, D > Class Template Reference

#include <key_stream.h>

Public Member Functions
	key_stream (std::unique_ptr< MDB_cursor, D > cur)
	Take ownership of cur without changing position. nullptr valid.
	key_stream (key_stream &&)=default
	key_stream (key_stream const &)=delete
	~key_stream ()=default
key_stream &	operator= (key_stream &&)=default
key_stream &	operator= (key_stream const &)=delete
std::unique_ptr< MDB_cursor, D >	give_cursor () noexcept
void	reset ()
key_iterator< K, V >	make_iterator () const
boost::iterator_range< key_iterator< K, V > >	make_range () const

Private Attributes
std::unique_ptr< MDB_cursor, D >	cur

Detailed Description

template<typename K, typename V, typename D>
class lmdb::key_stream< K, V, D >

C++ wrapper for a LMDB read-only cursor on a fixed-sized key K and value V.

Template Parameters

K	key type being stored by each record.
V	value type being stored by each record.
D	cleanup functor for the cursor; usually unique per db/table.

Constructor & Destructor Documentation

key_stream() [1/3]

template<typename K, typename V, typename D>

lmdb::key_stream< K, V, D >::key_stream ( std::unique_ptr< MDB_cursor, D > cur )

inlineexplicit

Take ownership of cur without changing position. nullptr valid.

key_stream() [2/3]

template<typename K, typename V, typename D>

lmdb::key_stream< K, V, D >::key_stream ( key_stream< K, V, D > && )

default

key_stream() [3/3]

template<typename K, typename V, typename D>

lmdb::key_stream< K, V, D >::key_stream ( key_stream< K, V, D > const & )

delete

~key_stream()

template<typename K, typename V, typename D>

lmdb::key_stream< K, V, D >::~key_stream ( )

default

Member Function Documentation

give_cursor()

template<typename K, typename V, typename D>

std::unique_ptr< MDB_cursor, D > lmdb::key_stream< K, V, D >::give_cursor ( )

inlinenoexcept

Give up ownership of the cursor. make_iterator() and make_range() can still be invoked, but return the empty set.

Returns

Currently owned LMDB cursor.

make_iterator()

template<typename K, typename V, typename D>

key_iterator< K, V > lmdb::key_stream< K, V, D >::make_iterator ( ) const

inline

Exceptions

std::system_error

if LMDB has unexpected errors.

Returns

C++ iterator over database keys from current cursor position that will reach .is_end() after the last key.

make_range()

template<typename K, typename V, typename D>

boost::iterator_range< key_iterator< K, V > > lmdb::key_stream< K, V, D >::make_range ( ) const

inline

Exceptions

std::system_error

if LMDB has unexpected errors.

Returns

Range from current cursor position until last key record. Useful in for-each range loops or in templated code

operator=() [1/2]

template<typename K, typename V, typename D>

key_stream & lmdb::key_stream< K, V, D >::operator= ( key_stream< K, V, D > && )

default

operator=() [2/2]

template<typename K, typename V, typename D>

key_stream & lmdb::key_stream< K, V, D >::operator= ( key_stream< K, V, D > const & )

delete

reset()

template<typename K, typename V, typename D>

void lmdb::key_stream< K, V, D >::reset ( )

inline

Place the stream back at the first key/value. Newly created iterators will start at the first value again.

Note

Invalidates all current iterators, including those created with make_iterator or make_range. Also invalidates all value_iterators created with key_iterator.

Member Data Documentation

cur

template<typename K, typename V, typename D>

std::unique_ptr<MDB_cursor, D> lmdb::key_stream< K, V, D >::cur

private

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

• src/lmdb/key_stream.h