Holds configuration parameters for engines. More...

#include <libpmemkv.hpp>

Public Member Functions
	config () noexcept
	Default constructor with uninitialized config. More...

	config (pmemkv_config *cfg) noexcept
	Creates config from pointer to pmemkv_config. More...

template<typename T >
status	put_data (const std::string &key, const T *value, const std::size_t number=1) noexcept
	Puts binary data pointed by value, of type T, with count of elements to a config. More...

template<typename T >
status	put_object (const std::string &key, T value, void(deleter)(void *)) noexcept
	Puts object pointed by value, of type T, with given destructor to a config. More...

template<typename T , typename D >
status	put_object (const std::string &key, std::unique_ptr< T, D > object) noexcept
	Puts unique_ptr (to an object) to a config. More...

status	put_uint64 (const std::string &key, std::uint64_t value) noexcept
	Puts std::uint64_t value to a config. More...

status	put_int64 (const std::string &key, std::int64_t value) noexcept
	Puts std::int64_t value to a config. More...

status	put_string (const std::string &key, const std::string &value) noexcept
	Puts string value to a config. More...

status	put_size (std::uint64_t size) noexcept
	Puts size to a config. More...

status	put_path (const std::string &path) noexcept
	Puts path to a config. More...

status	put_force_create (bool value) noexcept
	Puts force_create parameter to a config, For supporting engines If false, pmemkv opens file specified by 'path', otherwise it creates it. More...

status	put_oid (PMEMoid *oid) noexcept
	Puts PMEMoid object to a config. More...

template<typename Comparator >
status	put_comparator (Comparator &&comparator)
	Puts comparator object to a config. More...

template<typename T >
status	get_data (const std::string &key, T *&value, std::size_t &number) const noexcept
	Gets object from a config item with key name and copies it into T object value. More...

template<typename T >
status	get_object (const std::string &key, T *&value) const noexcept
	Gets binary data from a config item with key name and assigns pointer to T object value. More...

status	get_uint64 (const std::string &key, std::uint64_t &value) const noexcept
	Gets std::uint64_t value from a config item with key name. More...

status	get_int64 (const std::string &key, std::int64_t &value) const noexcept
	Gets std::int64_t value from a config item with key name. More...

status	get_string (const std::string &key, std::string &value) const noexcept
	Gets string value from a config item with key name. More...

pmemkv_config *	release () noexcept
	Similarly to std::unique_ptr::release it passes the ownership of underlying pmemkv_config variable and sets it to nullptr. More...

Private Member Functions
int	init () noexcept
	Initialization function for config. More...

Private Attributes
std::unique_ptr< pmemkv_config, decltype(&pmemkv_config_delete)>	config_

Detailed Description

Holds configuration parameters for engines.

It stores mappings of keys (strings) to values. A value can be: uint64_t, int64_t, string, binary data, pointer to an object (with accompanying deleter function).

It also delivers methods to store and read configuration items provided by a user. Once the configuration object is set (with all required parameters),pmemkv_open it can be passed to db::open() method.

List of options which are required by pmemkv database is specific to an engine. Every engine has documented all supported config parameters (please see libpmemkv(7) for details).

Constructor & Destructor Documentation

◆ config() [1/2]

pmem::kv::config::config ( )

inlinenoexcept

Default constructor with uninitialized config.

◆ config() [2/2]

pmem::kv::config::config ( pmemkv_config * cfg )

inlineexplicitnoexcept

Creates config from pointer to pmemkv_config.

Ownership is transferred to config class.

Member Function Documentation

◆ get_data()

template<typename T >

status pmem::kv::config::get_data	(	const std::string &	key,
		T *&	value,
		std::size_t &	count
	)		const

inlinenoexcept

Gets object from a config item with key name and copies it into T object value.

Parameters

[in]	key	The string representing config item's name.
[out]	value	The pointer to data.
[out]	count	The count of elements stored under reference.

Returns: pmem::kv::status

◆ get_int64()

status pmem::kv::config::get_int64	(	const std::string &	key,
		std::int64_t &	value
	)		const

inlinenoexcept

Gets std::int64_t value from a config item with key name.

Parameters

[in]	key	The string representing config item's name.
[out]	value	The std::int64_t value.

Returns: pmem::kv::status

◆ get_object()

template<typename T >

status pmem::kv::config::get_object	(	const std::string &	key,
		T *&	value
	)		const

inlinenoexcept

Gets binary data from a config item with key name and assigns pointer to T object value.

Parameters

[in]	key	The string representing config item's name.
[out]	value	The pointer to object.

Returns: pmem::kv::status

◆ get_string()

status pmem::kv::config::get_string	(	const std::string &	key,
		std::string &	value
	)		const

inlinenoexcept

Gets string value from a config item with key name.

Parameters

[in]	key	The string representing config item's name.
[out]	value	The string value.

Returns: pmem::kv::status

◆ get_uint64()

status pmem::kv::config::get_uint64	(	const std::string &	key,
		std::uint64_t &	value
	)		const

inlinenoexcept

Gets std::uint64_t value from a config item with key name.

Parameters

[in]	key	The string representing config item's name.
[out]	value	The std::uint64_t value.

Returns: pmem::kv::status

◆ init()

int pmem::kv::config::init ( )

inlineprivatenoexcept

Initialization function for config.

It's lazy initialized and called within all put functions.

Returns: int initialization result; 0 on success

◆ put_comparator()

template<typename Comparator >

status pmem::kv::config::put_comparator ( Comparator && comparator )

inline

Puts comparator object to a config.

Comparator must:

implement int compare(pmem::kv::string_view, pmem::kv::string_view)
implement std::string name()
be copy or move constructible
be thread-safe

Parameters

[in] comparator forwarding reference to a comparator

Returns: pmem::kv::status

Example implementation of custom comparator:

class lexicographical_comparator {
public:
    int compare(string_view k1, string_view k2)
    {
        if (k1.compare(k2) == 0)
            return 0;
        else if (std::lexicographical_compare(k1.data(), k1.data() + k1.size(),
                              k2.data(), k2.data() + k2.size()))
            return -1;
        else
            return 1;
    }
 
    std::string name()
    {
        return "lexicographical_comparator";
    }
};

And example usage (set in config and use while itarating over keys):

    config cfg;
 
    status s = cfg.put_path(argv[1]);
    ASSERT(s == status::OK);
    s = cfg.put_size(SIZE);
    ASSERT(s == status::OK);
    s = cfg.put_force_create(true);
    ASSERT(s == status::OK);
    s = cfg.put_comparator(lexicographical_comparator{});
    ASSERT(s == status::OK);
 
    LOG("Opening pmemkv database with 'csmap' engine");
    db *kv = new db();
    ASSERT(kv != nullptr);
    s = kv->open("csmap", std::move(cfg));
    ASSERT(s == status::OK);
 
    LOG("Putting new keys");
    s = kv->put("key1", "value1");
    ASSERT(s == status::OK);
    s = kv->put("key2", "value2");
    ASSERT(s == status::OK);
    s = kv->put("key3", "value3");
    ASSERT(s == status::OK);
 
    LOG("Iterating over existing keys in order specified by the comparator");
    kv->get_all([](string_view k, string_view v) {
        LOG("  visited: " << k.data());
        return 0;
    });

◆ put_data()

template<typename T >

status pmem::kv::config::put_data	(	const std::string &	key,
		const T *	value,
		const std::size_t	count = `1`
	)

inlinenoexcept

Puts binary data pointed by value, of type T, with count of elements to a config.

Count parameter is useful for putting arrays of data.

Parameters

[in]	key	The string representing config item's name.
[in]	value	The pointer to data.
[in]	count	The count of elements stored under reference.

Returns: pmem::kv::status

◆ put_force_create()

status pmem::kv::config::put_force_create ( bool value )

inlinenoexcept

Puts force_create parameter to a config, For supporting engines If false, pmemkv opens file specified by 'path', otherwise it creates it.

False by default.

Returns: pmem::kv::status

◆ put_int64()

status pmem::kv::config::put_int64	(	const std::string &	key,
		std::int64_t	value
	)

inlinenoexcept

Puts std::int64_t value to a config.

Parameters

[in]	key	The string representing config item's name.
[in]	value	The std::int64_t value.

Returns: pmem::kv::status

◆ put_object() [1/2]

template<typename T , typename D >

status pmem::kv::config::put_object	(	const std::string &	key,
		std::unique_ptr< T, D >	object
	)

inlinenoexcept

Puts unique_ptr (to an object) to a config.

Parameters

[in]	key	The string representing config item's name.
[in]	object	unique_ptr to an object.

Returns: pmem::kv::status

◆ put_object() [2/2]

template<typename T >

status pmem::kv::config::put_object	(	const std::string &	key,
		T *	value,
		void()(void )	deleter
	)

inlinenoexcept

Puts object pointed by value, of type T, with given destructor to a config.

Parameters

[in]	key	The string representing config item's name.
[in]	value	The pointer to object.
[in]	deleter	The object's destructor function.

Returns: pmem::kv::status

◆ put_oid()

status pmem::kv::config::put_oid ( PMEMoid * oid )

inlinenoexcept

Puts PMEMoid object to a config.

Parameters

[in] oid pointer (for details see libpmemobj(7)) which points to the engine data. If oid is null engine will allocate new data, otherwise it will use existing one.

Returns: pmem::kv::status

◆ put_path()

status pmem::kv::config::put_path ( const std::string & path )

inlinenoexcept

Puts path to a config.

Parameters

[in] path to a database file or to a poolset file (see poolset(5) for details). Note that when using poolset file, size should be 0.

Returns: pmem::kv::status

◆ put_size()

status pmem::kv::config::put_size ( std::uint64_t size )

inlinenoexcept

Puts size to a config.

Parameters

[in] size of the database in bytes.

Returns: pmem::kv::status

◆ put_string()

status pmem::kv::config::put_string	(	const std::string &	key,
		const std::string &	value
	)

inlinenoexcept

Puts string value to a config.

Parameters

[in]	key	The string representing config item's name.
[in]	value	The string value.

Returns: pmem::kv::status

◆ put_uint64()

status pmem::kv::config::put_uint64	(	const std::string &	key,
		std::uint64_t	value
	)

inlinenoexcept

Puts std::uint64_t value to a config.

Parameters

[in]	key	The string representing config item's name.
[in]	value	The std::uint64_t value.

Returns: pmem::kv::status

◆ release()

pmemkv_config * pmem::kv::config::release ( )

inlinenoexcept

Similarly to std::unique_ptr::release it passes the ownership of underlying pmemkv_config variable and sets it to nullptr.

Returns: handle to pmemkv_config

Member Data Documentation

◆ config_

std::unique_ptr<pmemkv_config, decltype(&pmemkv_config_delete)> pmem::kv::config::config_

private

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

/tmp/pmemkv-Vdq/src/libpmemkv.hpp

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ config() [1/2]

◆ config() [2/2]

Member Function Documentation

◆ get_data()

◆ get_int64()

◆ get_object()

◆ get_string()

◆ get_uint64()

◆ init()

◆ put_comparator()

◆ put_data()

◆ put_force_create()

◆ put_int64()

◆ put_object() [1/2]

◆ put_object() [2/2]

◆ put_oid()

◆ put_path()

◆ put_size()

◆ put_string()

◆ put_uint64()

◆ release()

Member Data Documentation

◆ config_