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Group cxx_core

Modules > cxx_core

Classes

Type Name
class mdbx::cache_entry
Cache entry for the transparent read-your-writes caching, see txn::get_cached() andmdbx_cache_get() .
class mdbx::cursor
Unmanaged cursor.
class mdbx::cursor_managed
Managed cursor.
class mdbx::env
Unmanaged database environment.
class mdbx::env_managed
Managed database environment.
struct mdbx::map_handle
A handle for an individual table (aka key-value space, maps or sub-database) in the environment.
class mdbx::txn
Unmanaged database transaction.
class mdbx::txn_managed
Managed database transaction.

Public Types

Type Name
typedef ::MDBX_cmp_func comparator
typedef env_managed::create_parameters create_parameters
Shorthand for env_managed::create_parameters .
typedef env::geometry geometry
Shorthand for env::geometry .
enum key_mode
Kinds of the keys and corresponding modes of comparing it.
enum loop_control
Loop control constants for readers enumeration functor and other cases.
typedef env::operate_options operate_options
Shorthand for env::operate_options .
typedef env::operate_parameters operate_parameters
Shorthand for env::operate_parameters .
enum put_mode
Key-value pairs put mode.
typedef env::reclaiming_options reclaiming_options
Shorthand for env::reclaiming_options .
enum value_mode
Kind of the values and sorted multi-values with corresponding comparison.

Public Functions

Type Name
comparator default_comparator (key_mode mode) noexcept
comparator default_comparator (value_mode mode) noexcept
MDBX_cmp_func get_datacmp (MDBX_db_flags_t flags)
Returns the built-in data (value) comparator for the given table flags, which is useful as a fallback when implementing custom comparators.
MDBX_CXX01_CONSTEXPR_ENUM bool is_msgpack (key_mode mode) noexcept
MDBX_CXX01_CONSTEXPR_ENUM bool is_msgpack (value_mode mode) noexcept
MDBX_CXX01_CONSTEXPR_ENUM bool is_multi (value_mode mode) noexcept
MDBX_CXX01_CONSTEXPR_ENUM bool is_ordinal (key_mode mode) noexcept
MDBX_CXX01_CONSTEXPR_ENUM bool is_ordinal (value_mode mode) noexcept
bool is_readahead_reasonable (size_t volume, intptr_t redundancy)
Quickly finds out whether readahead is reasonable for the given data volume and redundancy.
MDBX_CXX01_CONSTEXPR_ENUM bool is_reverse (key_mode mode) noexcept
MDBX_CXX01_CONSTEXPR_ENUM bool is_reverse (value_mode mode) noexcept
MDBX_CXX01_CONSTEXPR_ENUM bool is_samelength (key_mode mode) noexcept
MDBX_CXX01_CONSTEXPR_ENUM bool is_samelength (value_mode mode) noexcept
MDBX_CXX01_CONSTEXPR_ENUM bool is_usual (key_mode mode) noexcept
MDBX_CXX01_CONSTEXPR_ENUM bool is_usual (value_mode mode) noexcept
inline ::std::string ratio2digits (uint64_t numerator, uint64_t denominator, int precision)
Converts a fraction to a string of decimal digits without using floating-point operations.
inline ::std::string ratio2percents (uint64_t value, uint64_t whole)
Converts a fraction to a percentage string without using floating-point operations.
void set_panic (MDBX_panic_func func)
Sets a callback for assertion failures, called before printing the message and aborting.
int setup_debug (MDBX_log_level_t log_level=MDBX_LOG_DONTCHANGE, MDBX_debug_flags_t debug_flags=MDBX_DBG_DONTCHANGE, MDBX_debug_func logger=nullptr)
Sets up the global log-level, debug options and logger.
int setup_debug_nofmt (MDBX_log_level_t log_level, MDBX_debug_flags_t debug_flags, MDBX_debug_func_nofmt logger, char * logger_buffer, size_t logger_buffer_size)
Sets up the global log-level, debug options and a logger for plain preformatted messages.

Public Types Documentation

typedef comparator

using mdbx::comparator = ::MDBX_cmp_func;

typedef create_parameters

Shorthand for env_managed::create_parameters .

using mdbx::create_parameters = env_managed::create_parameters;

typedef geometry

Shorthand for env::geometry .

using mdbx::geometry = env::geometry;

enum key_mode

Kinds of the keys and corresponding modes of comparing it. 

enum key_mode {
    usual = MDBX_DB_DEFAULTS,
    reverse = MDBX_REVERSEKEY,
    ordinal = MDBX_INTEGERKEY,
    msgpack = -1
};

enum loop_control

Loop control constants for readers enumeration functor and other cases. 

enum loop_control {
    continue_loop = 0,
    exit_loop = INT32_MIN
};

See also: env::enumerate_readers()

typedef operate_options

Shorthand for env::operate_options .

using mdbx::operate_options = env::operate_options;

typedef operate_parameters

Shorthand for env::operate_parameters .

using mdbx::operate_parameters = env::operate_parameters;

enum put_mode

Key-value pairs put mode. 

enum put_mode {
    insert_unique = MDBX_NOOVERWRITE,
    upsert = MDBX_UPSERT,
    update = MDBX_CURRENT
};

typedef reclaiming_options

Shorthand for env::reclaiming_options .

using mdbx::reclaiming_options = env::reclaiming_options;

enum value_mode

Kind of the values and sorted multi-values with corresponding comparison. 

enum value_mode {
    single = MDBX_DB_DEFAULTS,
    multi = MDBX_DUPSORT,
    multi_reverse = MDBX_DUPSORT | MDBX_REVERSEDUP,
    multi_samelength = MDBX_DUPSORT | MDBX_DUPFIXED,
    multi_ordinal = MDBX_DUPSORT | MDBX_DUPFIXED | MDBX_INTEGERDUP,
    multi_reverse_samelength =
      MDBX_DUPSORT | MDBX_REVERSEDUP | MDBX_DUPFIXED,
    msgpack = -1
};

Public Functions Documentation

function default_comparator

inline comparator default_comparator (
    key_mode mode
) noexcept

function default_comparator

inline comparator default_comparator (
    value_mode mode
) noexcept

function get_datacmp

Returns the built-in data (value) comparator for the given table flags, which is useful as a fallback when implementing custom comparators. 

inline MDBX_cmp_func get_datacmp (
    MDBX_db_flags_t flags
)

See also: mdbx_get_datacmp()

function is_msgpack

MDBX_CXX01_CONSTEXPR_ENUM bool is_msgpack (
    key_mode mode
) noexcept

function is_msgpack

MDBX_CXX01_CONSTEXPR_ENUM bool is_msgpack (
    value_mode mode
) noexcept

function is_multi

MDBX_CXX01_CONSTEXPR_ENUM bool is_multi (
    value_mode mode
) noexcept

function is_ordinal

MDBX_CXX01_CONSTEXPR_ENUM bool is_ordinal (
    key_mode mode
) noexcept

function is_ordinal

MDBX_CXX01_CONSTEXPR_ENUM bool is_ordinal (
    value_mode mode
) noexcept

function is_readahead_reasonable

Quickly finds out whether readahead is reasonable for the given data volume and redundancy. 

inline bool is_readahead_reasonable (
    size_t volume,
    intptr_t redundancy
)

See also: mdbx_is_readahead_reasonable()

function is_reverse

MDBX_CXX01_CONSTEXPR_ENUM bool is_reverse (
    key_mode mode
) noexcept

function is_reverse

MDBX_CXX01_CONSTEXPR_ENUM bool is_reverse (
    value_mode mode
) noexcept

function is_samelength

MDBX_CXX01_CONSTEXPR_ENUM bool is_samelength (
    key_mode mode
) noexcept

function is_samelength

MDBX_CXX01_CONSTEXPR_ENUM bool is_samelength (
    value_mode mode
) noexcept

function is_usual

MDBX_CXX01_CONSTEXPR_ENUM bool is_usual (
    key_mode mode
) noexcept

function is_usual

MDBX_CXX01_CONSTEXPR_ENUM bool is_usual (
    value_mode mode
) noexcept

function ratio2digits

Converts a fraction to a string of decimal digits without using floating-point operations. 

inline ::std::string ratio2digits (
    uint64_t numerator,
    uint64_t denominator,
    int precision
)

See also: mdbx_ratio2digits()

function ratio2percents

Converts a fraction to a percentage string without using floating-point operations. 

inline ::std::string ratio2percents (
    uint64_t value,
    uint64_t whole
)

See also: mdbx_ratio2percents()

function set_panic

Sets a callback for assertion failures, called before printing the message and aborting. 

inline void set_panic (
    MDBX_panic_func func
)

See also: mdbx_set_panic()

function setup_debug

Sets up the global log-level, debug options and logger. 

inline int setup_debug (
    MDBX_log_level_t log_level=MDBX_LOG_DONTCHANGE,
    MDBX_debug_flags_t debug_flags=MDBX_DBG_DONTCHANGE,
    MDBX_debug_func logger=nullptr
)

Returns:

A non-negative value on success (previous settings packed into the low 16 bits and high 16 bits), or a negative error.

See also: mdbx_setup_debug()

function setup_debug_nofmt

Sets up the global log-level, debug options and a logger for plain preformatted messages. 

inline int setup_debug_nofmt (
    MDBX_log_level_t log_level,
    MDBX_debug_flags_t debug_flags,
    MDBX_debug_func_nofmt logger,
    char * logger_buffer,
    size_t logger_buffer_size
)

Returns:

A non-negative value on success, or a negative error.

See also: mdbx_setup_debug_nofmt()