taia(3)taia(3)NAMEtaia - manipulate times with 1-attosecond precision
SYNTAX
#include <taia.h>
double taia_approx(&t);
double taia_frac(&t);
void taia_tai(&t,&sec);
int taia_less(&a,&b);
void taia_add(&t,&a,&b);
void taia_sub(&t,&a,&b);
void taia_half(&t,&a);
unsigned int taia_fmtfrac(s,&t);
struct taia t;
struct taia a;
struct taia b;
struct tai sec;
char *s;
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.
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 inte‐
ger 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 differ‐
ence 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 dig‐
its, 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 ALSOtaia_now(3), taia_pack(3), tai(3)taia(3)
