taia
3
user commands
djbwares
taia
manipulate times with 1-attosecond precision
#include <taia.h>
double \fBtaia_approx\fP(&\fIt\fR);
double \fBtaia_frac\fP(&\fIt\fR);
void \fBtaia_tai\fP(&\fIt\fR,&\fIsec\fR);
int \fBtaia_less\fP(&\fIa\fR,&\fIb\fR);
void \fBtaia_add\fP(&\fIt\fR,&\fIa\fR,&\fIb\fR);
void \fBtaia_sub\fP(&\fIt\fR,&\fIa\fR,&\fIb\fR);
void \fBtaia_half\fP(&\fIt\fR,&\fIa\fR);
unsigned int \fBtaia_fmtfrac\fP(\fIs\fR,&\fIt\fR);
struct taia \fIt\fR;
struct taia \fIa\fR;
struct taia \fIb\fR;
struct tai \fIsec\fR;
char *\fIs\fR;
Description
A
struct taia
stores an integer between 0 inclusive and 2^64x10^18 exclusive.
The format of
struct taia
is designed to speed up common operations;
applications should not look inside
struct taia\fR.
A
struct taia
variable is commonly used to store
a TAI64NA label.
Each TAI64NA label refers to one attosecond of real time;
see
http://pobox.com/~djb/proto/tai64.txt
for more information.
The integer in the
struct taia
is 10^18 times the second count,
plus 10^9 times the nanosecond count,
plus the attosecond count.
A
struct taia
variable may also be used to store
the numerical difference between two TAI64NA labels.
Arithmetic
taia_approx
returns a double-precision approximation to
t/10^18.
The result of
taia_approx
is always nonnegative.
taia_tai
places into
sec
the integer part of
t/10^18.
taia_frac
returns a double-precision approximation to
the fraction part of
t/10^18.
The result of
taia_frac
is always nonnegative.
taia_less
returns 1 if
a
is smaller than
b,
0 otherwise.
taia_add
adds
a
and
b
modulo 2^64x10^18
and puts the result into
t.
The inputs and outputs may overlap.
taia_sub
subtracts
b
from
a
modulo 2^64x10^18
and puts the result into
t.
The inputs and outputs may overlap.
taia_half
divides
a
by 2, rounding down,
and puts the result into
t.
The input and output may overlap.
Formatting
taia_fmtfrac
prints the remainder of
t/10^18,
padded to exactly 18 digits,
into the character buffer
s,
without a terminating NUL.
It returns 18, the number of characters written.
s
may be zero;
then
taia_fmtfrac
returns 18 without printing anything.
The macro
TAIA_FMTFRAC
is defined as 19;
this is enough space for the output of
taia_fmtfrac
and a terminating NUL.
See also
taia_now3
taia_pack3
tai3
Author
Original code and documentation by Daniel J. Bernstein.
Converted to DocBook XML by Jonathan de Boyne Pollard.