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Eliminate isort 

This saves a few bytes of static storage and less instructions are
executed when looking for the best offset.

Signed-off-by: Georg Sauthoff <mail@gms.tf>
master
Georg Sauthoff 2020-06-21 11:14:45 +02:00 committed by Richard Cochran
parent bf0a644b99
commit b6fa222201
1 changed files with 27 additions and 28 deletions
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55
sysoff.c
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@ -34,12 +34,6 @@ static int64_t pctns(struct ptp_clock_time *t)
return t->sec * NS_PER_SEC + t->nsec; return t->sec * NS_PER_SEC + t->nsec;
} }
static struct {
int64_t interval;
int64_t offset;
uint64_t timestamp;
} samples[PTP_MAX_SAMPLES];
static int sysoff_precise(int fd, int64_t *result, uint64_t *ts) static int sysoff_precise(int fd, int64_t *result, uint64_t *ts)
{ {
#ifdef PTP_SYS_OFFSET_PRECISE #ifdef PTP_SYS_OFFSET_PRECISE
@ -57,28 +51,28 @@ static int sysoff_precise(int fd, int64_t *result, uint64_t *ts)
#endif #endif
} }
static void insertion_sort(int length, int64_t interval, int64_t offset, uint64_t ts)
{
int i = length - 1;
while (i >= 0) {
if (samples[i].interval < interval)
break;
samples[i+1] = samples[i];
i--;
}
samples[i+1].interval = interval;
samples[i+1].offset = offset;
samples[i+1].timestamp = ts;
}
static int64_t sysoff_estimate(struct ptp_clock_time *pct, int extended, static int64_t sysoff_estimate(struct ptp_clock_time *pct, int extended,
int n_samples, uint64_t *ts, int64_t *delay) int n_samples, uint64_t *ts, int64_t *delay)
{ {
int64_t t1, t2, tp; int64_t t1, t2, tp;
int64_t interval, offset; int64_t interval, timestamp, offset;
int i; int64_t shortest_interval, best_timestamp, best_offset;
int i = 0;
for (i = 0; i < n_samples; i++) { if (extended) {
t1 = pctns(&pct[3*i]);
tp = pctns(&pct[3*i+1]);
t2 = pctns(&pct[3*i+2]);
} else {
t1 = pctns(&pct[2*i]);
tp = pctns(&pct[2*i+1]);
t2 = pctns(&pct[2*i+2]);
}
shortest_interval = t2 - t1;
best_timestamp = (t2 + t1) / 2;
best_offset = best_timestamp - tp;
for (i = 1; i < n_samples; i++) {
if (extended) { if (extended) {
t1 = pctns(&pct[3*i]); t1 = pctns(&pct[3*i]);
tp = pctns(&pct[3*i+1]); tp = pctns(&pct[3*i+1]);
@ -89,12 +83,17 @@ static int64_t sysoff_estimate(struct ptp_clock_time *pct, int extended,
t2 = pctns(&pct[2*i+2]); t2 = pctns(&pct[2*i+2]);
} }
interval = t2 - t1; interval = t2 - t1;
offset = (t2 + t1) / 2 - tp; timestamp = (t2 + t1) / 2;
insertion_sort(i, interval, offset, (t2 + t1) / 2); offset = timestamp - tp;
if (interval < shortest_interval) {
shortest_interval = interval;
best_timestamp = timestamp;
best_offset = offset;
} }
*ts = samples[0].timestamp; }
*delay = samples[0].interval; *ts = best_timestamp;
return samples[0].offset; *delay = shortest_interval;
return best_offset;
} }
static int sysoff_extended(int fd, int n_samples, static int sysoff_extended(int fd, int n_samples,