mdbx::env::geometry Struct Reference

Database geometry for size management. More...

#include <mdbx.h++>

Classes
struct	size
	Tagged type for output to std::ostream. More...

Public Types
enum	: int64_t {   default_value = -1, minimal_value = 0, maximal_value = INTPTR_MAX, kB = 1000,   MB = kB * 1000, GB = MB * 1000, TB = GB * 1000, PB = TB * 1000,   EB = PB * 1000, KiB = 1024, MiB = KiB << 10, GiB = MiB << 10,   TiB = GiB << 10, PiB = TiB << 10, EiB = PiB << 10 }

Public Member Functions
geometry &	make_fixed (intptr_t size) noexcept
geometry &	make_dynamic (intptr_t lower=minimal_value, intptr_t upper=maximal_value) noexcept
MDBX_CXX11_CONSTEXPR	geometry () noexcept
MDBX_CXX11_CONSTEXPR	geometry (const geometry &) noexcept=default
MDBX_CXX11_CONSTEXPR	geometry (intptr_t size_lower, intptr_t size_now=default_value, intptr_t size_upper=maximal_value, intptr_t growth_step=default_value, intptr_t shrink_threshold=default_value, intptr_t pagesize=default_value) noexcept

Public Attributes
intptr_t	size_lower {minimal_value}
	The lower bound of database size in bytes. More...
intptr_t	size_now {default_value}
	The size in bytes to setup the database size for now. More...
intptr_t	size_upper {maximal_value}
	The upper bound of database size in bytes. More...
intptr_t	growth_step {default_value}
	The growth step in bytes, must be greater than zero to allow the database to grow. More...
intptr_t	shrink_threshold {default_value}
	The shrink threshold in bytes, must be greater than zero to allow the database to shrink. More...
intptr_t	pagesize {default_value}
	The database page size for new database creation or default_value otherwise. More...

Detailed Description

Database geometry for size management.

Member Enumeration Documentation

anonymous enum

anonymous enum : int64_t

Enumerator
default_value	Means "keep current or use default".
minimal_value	Means "minimal acceptable".
maximal_value	Means "maximal acceptable".
kB	\(10^{3}\) bytes
MB	\(10^{6}\) bytes
GB	\(10^{9}\) bytes
TB	\(10^{12}\) bytes
PB	\(10^{15}\) bytes
EB	\(10^{18}\) bytes
KiB	\(2^{10}\) bytes
MiB	\(2^{20}\) bytes
GiB	\(2^{30}\) bytes
TiB	\(2^{40}\) bytes
PiB	\(2^{50}\) bytes
EiB	\(2^{60}\) bytes

Constructor & Destructor Documentation

geometry() [1/3]

MDBX_CXX11_CONSTEXPR mdbx::env::geometry::geometry ( )

inlinenoexcept

geometry() [2/3]

MDBX_CXX11_CONSTEXPR mdbx::env::geometry::geometry ( const geometry &  )

defaultnoexcept

geometry() [3/3]

MDBX_CXX11_CONSTEXPR mdbx::env::geometry::geometry ( intptr_t  size_lower, intptr_t  size_now = default_value, intptr_t  size_upper = maximal_value, intptr_t  growth_step = default_value, intptr_t  shrink_threshold = default_value, intptr_t  pagesize = default_value  )

inlinenoexcept

Member Function Documentation

make_dynamic()

env::geometry & mdbx::env::geometry::make_dynamic ( intptr_t  lower = minimal_value, intptr_t  upper = maximal_value  )

inlinenoexcept

make_fixed()

env::geometry & mdbx::env::geometry::make_fixed ( intptr_t  size )

inlinenoexcept

Member Data Documentation

growth_step

intptr_t mdbx::env::geometry::growth_step {default_value}

The growth step in bytes, must be greater than zero to allow the database to grow.

pagesize

intptr_t mdbx::env::geometry::pagesize {default_value}

The database page size for new database creation or default_value otherwise.

Must be power of 2 in the range between MDBX_MIN_PAGESIZE and MDBX_MAX_PAGESIZE.

shrink_threshold

intptr_t mdbx::env::geometry::shrink_threshold {default_value}

The shrink threshold in bytes, must be greater than zero to allow the database to shrink.

size_lower

intptr_t mdbx::env::geometry::size_lower {minimal_value}

The lower bound of database size in bytes.

size_now

intptr_t mdbx::env::geometry::size_now {default_value}

The size in bytes to setup the database size for now.

It is recommended always pass default_value in this argument except some special cases.

size_upper

intptr_t mdbx::env::geometry::size_upper {maximal_value}

The upper bound of database size in bytes.

It is recommended to avoid change upper bound while database is used by other processes or threaded (i.e. just pass default_value in this argument except absolutely necessary). Otherwise you must be ready for MDBX_UNABLE_EXTEND_MAPSIZE error(s), unexpected pauses during remapping and/or system errors like "address busy", and so on. In other words, there is no way to handle a growth of the upper bound robustly because there may be a lack of appropriate system resources (which are extremely volatile in a multi-process multi-threaded environment).

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

• mdbx.h++