/* $NetBSD: timevalops.h,v 1.5 2020/05/25 20:47:20 christos Exp $ */
/*
* timevalops.h -- calculations on 'struct timeval' values
*
* Written by Juergen Perlinger (
[email protected]) for the NTP project.
* The contents of 'html/copyright.html' apply.
*
* For a rationale look at 'timespecops.h'; we do the same here, but the
* normalisation keeps the microseconds in [0 .. 10^6[, of course.
*/
#ifndef TIMEVALOPS_H
#define TIMEVALOPS_H
#include <sys/types.h>
#include <stdio.h>
#include "ntp.h"
#include "timetoa.h"
/* microseconds per second */
#define MICROSECONDS 1000000
#ifndef HAVE_U_INT64
# define USE_TSF_USEC_TABLES
#endif
/*
* Convert usec to a time stamp fraction.
*/
#ifdef USE_TSF_USEC_TABLES
extern const u_int32 ustotslo[];
extern const u_int32 ustotsmid[];
extern const u_int32 ustotshi[];
# define TVUTOTSF(tvu, tsf) \
((tsf) = ustotslo[(tvu) & 0xff] \
+ ustotsmid[((tvu) >> 8) & 0xff] \
+ ustotshi[((tvu) >> 16) & 0xf])
#else
# define TVUTOTSF(tvu, tsf) \
((tsf) = (u_int32) \
((((u_int64)(tvu) << 32) + MICROSECONDS / 2) / \
MICROSECONDS))
#endif
/*
* Convert a time stamp fraction to microseconds. The time stamp
* fraction is assumed to be unsigned.
*/
#ifdef USE_TSF_USEC_TABLES
extern const u_int32 tstouslo[256];
extern const u_int32 tstousmid[256];
extern const u_int32 tstoushi[128];
/*
* TV_SHIFT is used to turn the table result into a usec value. To
* round, add in TV_ROUNDBIT before shifting.
*/
#define TV_SHIFT 3
#define TV_ROUNDBIT 0x4
# define TSFTOTVU(tsf, tvu) \
((tvu) = (tstoushi[((tsf) >> 24) & 0xff] \
+ tstousmid[((tsf) >> 16) & 0xff] \
+ tstouslo[((tsf) >> 9) & 0x7f] \
+ TV_ROUNDBIT) >> TV_SHIFT)
#else
# define TSFTOTVU(tsf, tvu) \
((tvu) = (int32) \
(((u_int64)(tsf) * MICROSECONDS + 0x80000000) >> 32))
#endif
/*
* Convert a struct timeval to a time stamp.
*/
#define TVTOTS(tv, ts) \
do { \
(ts)->l_ui = (u_long)(tv)->tv_sec; \
TVUTOTSF((tv)->tv_usec, (ts)->l_uf); \
} while (FALSE)
#define sTVTOTS(tv, ts) \
do { \
int isneg = 0; \
long usec; \
(ts)->l_ui = (tv)->tv_sec; \
usec = (tv)->tv_usec; \
if (((tv)->tv_sec < 0) || ((tv)->tv_usec < 0)) { \
usec = -usec; \
(ts)->l_ui = -(ts)->l_ui; \
isneg = 1; \
} \
TVUTOTSF(usec, (ts)->l_uf); \
if (isneg) { \
L_NEG((ts)); \
} \
} while (FALSE)
/*
* Convert a time stamp to a struct timeval. The time stamp
* has to be positive.
*/
#define TSTOTV(ts, tv) \
do { \
(tv)->tv_sec = (ts)->l_ui; \
TSFTOTVU((ts)->l_uf, (tv)->tv_usec); \
if ((tv)->tv_usec == 1000000) { \
(tv)->tv_sec++; \
(tv)->tv_usec = 0; \
} \
} while (FALSE)
/*
* predicate: returns TRUE if the microseconds are in nominal range
* use like: int timeval_isnormal(const struct timeval *x)
*/
#define timeval_isnormal(x) \
((x)->tv_usec >= 0 && (x)->tv_usec < MICROSECONDS)
/*
* Convert milliseconds to a time stamp fraction. Unused except for
* refclock_leitch.c, so accompanying lookup tables were removed in
* favor of reusing the microseconds conversion tables.
*/
#define MSUTOTSF(msu, tsf) TVUTOTSF((msu) * 1000, tsf)
/*
* predicate: returns TRUE if the microseconds are out-of-bounds
* use like: int timeval_isdenormal(const struct timeval *x)
*/
#define timeval_isdenormal(x) (!timeval_isnormal(x))
/* make sure microseconds are in nominal range */
static inline struct timeval
normalize_tval(
struct timeval x
)
{
long z;
/*
* If the fraction becomes excessive denormal, we use division
* to do first partial normalisation. The normalisation loops
* following will do the remaining cleanup. Since the size of
* tv_usec has a peculiar definition by the standard the range
* check is coded manually. And labs() is intentionally not used
* here: it has implementation-defined behaviour when applied
* to LONG_MIN.
*/
if (x.tv_usec < -3l * MICROSECONDS ||
x.tv_usec > 3l * MICROSECONDS ) {
z = x.tv_usec / MICROSECONDS;
x.tv_usec -= z * MICROSECONDS;
x.tv_sec += z;
}
/*
* Do any remaining normalisation steps in loops. This takes 3
* steps max, and should outperform a division even if the
* mul-by-inverse trick is employed. (It also does the floor
* division adjustment if the above division was executed.)
*/
if (x.tv_usec < 0)
do {
x.tv_usec += MICROSECONDS;
x.tv_sec--;
} while (x.tv_usec < 0);
else if (x.tv_usec >= MICROSECONDS)
do {
x.tv_usec -= MICROSECONDS;
x.tv_sec++;
} while (x.tv_usec >= MICROSECONDS);
return x;
}
/* x = a + b */
static inline struct timeval
add_tval(
struct timeval a,
struct timeval b
)
{
struct timeval x;
x = a;
x.tv_sec += b.tv_sec;
x.tv_usec += b.tv_usec;
return normalize_tval(x);
}
/* x = a + b, b is fraction only */
static inline struct timeval
add_tval_us(
struct timeval a,
long b
)
{
struct timeval x;
x = a;
x.tv_usec += b;
return normalize_tval(x);
}
/* x = a - b */
static inline struct timeval
sub_tval(
struct timeval a,
struct timeval b
)
{
struct timeval x;
x = a;
x.tv_sec -= b.tv_sec;
x.tv_usec -= b.tv_usec;
return normalize_tval(x);
}
/* x = a - b, b is fraction only */
static inline struct timeval
sub_tval_us(
struct timeval a,
long b
)
{
struct timeval x;
x = a;
x.tv_usec -= b;
return normalize_tval(x);
}
/* x = -a */
static inline struct timeval
neg_tval(
struct timeval a
)
{
struct timeval x;
x.tv_sec = -a.tv_sec;
x.tv_usec = -a.tv_usec;
return normalize_tval(x);
}
/* x = abs(a) */
static inline struct timeval
abs_tval(
struct timeval a
)
{
struct timeval c;
c = normalize_tval(a);
if (c.tv_sec < 0) {
if (c.tv_usec != 0) {
c.tv_sec = -c.tv_sec - 1;
c.tv_usec = MICROSECONDS - c.tv_usec;
} else {
c.tv_sec = -c.tv_sec;
}
}
return c;
}
/*
* compare previously-normalised a and b
* return 1 / 0 / -1 if a < / == / > b
*/
static inline int
cmp_tval(
struct timeval a,
struct timeval b
)
{
int r;
r = (a.tv_sec > b.tv_sec) - (a.tv_sec < b.tv_sec);
if (0 == r)
r = (a.tv_usec > b.tv_usec) -
(a.tv_usec < b.tv_usec);
return r;
}
/*
* compare possibly-denormal a and b
* return 1 / 0 / -1 if a < / == / > b
*/
static inline int
cmp_tval_denorm(
struct timeval a,
struct timeval b
)
{
return cmp_tval(normalize_tval(a), normalize_tval(b));
}
/*
* test previously-normalised a
* return 1 / 0 / -1 if a < / == / > 0
*/
static inline int
test_tval(
struct timeval a
)
{
int r;
r = (a.tv_sec > 0) - (a.tv_sec < 0);
if (r == 0)
r = (a.tv_usec > 0);
return r;
}
/*
* test possibly-denormal a
* return 1 / 0 / -1 if a < / == / > 0
*/
static inline int
test_tval_denorm(
struct timeval a
)
{
return test_tval(normalize_tval(a));
}
/* return LIB buffer ptr to string rep */
static inline const char *
tvaltoa(
struct timeval x
)
{
return format_time_fraction(x.tv_sec, x.tv_usec, 6);
}
/* convert from timeval duration to l_fp duration */
static inline l_fp
tval_intv_to_lfp(
struct timeval x
)
{
struct timeval v;
l_fp y;
v = normalize_tval(x);
TVUTOTSF(v.tv_usec, y.l_uf);
y.l_i = (int32)v.tv_sec;
return y;
}
/* x must be UN*X epoch, output *y will be in NTP epoch */
static inline l_fp
tval_stamp_to_lfp(
struct timeval x
)
{
l_fp y;
y = tval_intv_to_lfp(x);
y.l_ui += JAN_1970;
return y;
}
/* convert to l_fp type, relative signed/unsigned and absolute */
static inline struct timeval
lfp_intv_to_tval(
l_fp x
)
{
struct timeval out;
l_fp absx;
int neg;
neg = L_ISNEG(&x);
absx = x;
if (neg) {
L_NEG(&absx);
}
TSFTOTVU(absx.l_uf, out.tv_usec);
out.tv_sec = absx.l_i;
if (neg) {
out.tv_sec = -out.tv_sec;
out.tv_usec = -out.tv_usec;
out = normalize_tval(out);
}
return out;
}
static inline struct timeval
lfp_uintv_to_tval(
l_fp x
)
{
struct timeval out;
TSFTOTVU(x.l_uf, out.tv_usec);
out.tv_sec = x.l_ui;
return out;
}
/*
* absolute (timestamp) conversion. Input is time in NTP epoch, output
* is in UN*X epoch. The NTP time stamp will be expanded around the
* pivot time *p or the current time, if p is NULL.
*/
static inline struct timeval
lfp_stamp_to_tval(
l_fp x,
const time_t * p
)
{
struct timeval out;
vint64 sec;
sec = ntpcal_ntp_to_time(x.l_ui, p);
TSFTOTVU(x.l_uf, out.tv_usec);
/* copying a vint64 to a time_t needs some care... */
#if SIZEOF_TIME_T <= 4
out.tv_sec = (time_t)sec.d_s.lo;
#elif defined(HAVE_INT64)
out.tv_sec = (time_t)sec.q_s;
#else
out.tv_sec = ((time_t)sec.d_s.hi << 32) | sec.d_s.lo;
#endif
out = normalize_tval(out);
return out;
}
#endif /* TIMEVALOPS_H */
