Group value2key

Value-to-Key functions to avoid using custom comparators .More...

Public Functions

Type	Name
LIBMDBX_API uint64_t	mdbx_key_from_double (const double ieee754_64bit) Make a 8-byte key from a `double` IEEE754 value.
LIBMDBX_API uint32_t	mdbx_key_from_float (const float ieee754_32bit) Make a 4-byte key from a `float` IEEE754 value.
uint32_t	mdbx_key_from_int32 (const int32_t i32) Make a 4-byte key from a signed `int32_t` value.
uint64_t	mdbx_key_from_int64 (const int64_t i64) Make a 8-byte key from a signed `int64_t` value.
LIBMDBX_API uint64_t	mdbx_key_from_jsonInteger (const int64_t json_integer) Make a 8-byte key from a signed `int64_t` JSON-number value.
LIBMDBX_API uint64_t	mdbx_key_from_ptrdouble (const double const ieee754_64bit) Make a 8-byte key from a* `double` IEEE754 value by a pointer.
LIBMDBX_API uint32_t	mdbx_key_from_ptrfloat (const float const ieee754_32bit) Make a 4-byte key from a* `float` IEEE754 value by a pointer.

Detailed Description

See also: Key-to-Value functions The mdbx_key_from_jsonInteger() build a keys which are comparable with keys created by mdbx_key_from_double(). So this allows mixing int64_t and IEEE754 double values in one index for JSON-numbers with restriction for integer numbers range corresponding to RFC-7159, i.e. ([-2^{53}+1, 2^{53}-1]). See bottom of page 6 at https://tools.ietf.org/html/rfc7159

Public Functions Documentation

function mdbx_key_from_double

Make a 8-byte key from a double IEEE754 value.

LIBMDBX_API uint64_t mdbx_key_from_double (
    const double ieee754_64bit
)

Parameters:

ieee754_64bit The value to be converted.

Returns:

The 8-byte key that is comparable with other keys made from double values, i.e. the order of keys is the same as the order of the original values.

function mdbx_key_from_float

Make a 4-byte key from a float IEEE754 value.

LIBMDBX_API uint32_t mdbx_key_from_float (
    const float ieee754_32bit
)

Parameters:

ieee754_32bit The value to be converted.

Returns:

The 4-byte key that is comparable with other keys made from float values, i.e. the order of keys is the same as the order of the original values.

function mdbx_key_from_int32

Make a 4-byte key from a signed int32_t value.

inline uint32_t mdbx_key_from_int32 (
    const int32_t i32
)

Parameters:

i32 The value to be converted.

Returns:

The 4-byte key that is comparable with other keys made from int32_t values, i.e. the order of keys is the same as the order of the original values.

function mdbx_key_from_int64

Make a 8-byte key from a signed int64_t value.

inline uint64_t mdbx_key_from_int64 (
    const int64_t i64
)

Parameters:

i64 The value to be converted.

Returns:

The 8-byte key that is comparable with other keys made from int64_t values, i.e. the order of keys is the same as the order of the original values.

function mdbx_key_from_jsonInteger

Make a 8-byte key from a signed int64_t JSON-number value.

LIBMDBX_API uint64_t mdbx_key_from_jsonInteger (
    const int64_t json_integer
)

The resulting keys are comparable with keys created by mdbx_key_from_double(), so this allows mixing int64_t and IEEE754 double values in one index for JSON-numbers.

Parameters:

json_integer The value to be converted.

Returns:

The 8-byte key that is comparable with keys made from double values, i.e. the order of keys is the same as the order of the original values.

function mdbx_key_from_ptrdouble

Make a 8-byte key from a double IEEE754 value by a pointer.

LIBMDBX_API uint64_t mdbx_key_from_ptrdouble (
    const double *const ieee754_64bit
)

Parameters:

ieee754_64bit The address of the value to be converted.

Returns:

The 8-byte key that is comparable with other keys made from double values.

function mdbx_key_from_ptrfloat

Make a 4-byte key from a float IEEE754 value by a pointer.

LIBMDBX_API uint32_t mdbx_key_from_ptrfloat (
    const float *const ieee754_32bit
)

Parameters:

ieee754_32bit The address of the value to be converted.

Returns:

The 4-byte key that is comparable with other keys made from float values.