blob: 4a3b8428f71061b83e8c3906a8cd729469fb97b7 [file] [log] [blame]
 /* * Copyright (c) 2019 Peter Bigot Consulting, LLC * * SPDX-License-Identifier: Apache-2.0 */ /* * The time_days_from_civil function is derived directly from public * domain content written by Howard Hinnant and available at: * http://howardhinnant.github.io/date_algorithms.html#days_from_civil */ #include #include #include #include /** Convert a civil (proleptic Gregorian) date to days relative to * 1970-01-01. * * @param y the calendar year * @param m the calendar month, in the range [1, 12] * @param d the day of the month, in the range [1, last_day_of_month(y, m)] * * @return the signed number of days between the specified day and * 1970-01-01 * * @see http://howardhinnant.github.io/date_algorithms.html#days_from_civil */ static int64_t time_days_from_civil(int64_t y, unsigned int m, unsigned int d) { y -= m <= 2; int64_t era = (y >= 0 ? y : y - 399) / 400; unsigned int yoe = y - era * 400; unsigned int doy = (153U * (m + (m > 2 ? -3 : 9)) + 2U) / 5U + d; unsigned int doe = yoe * 365U + yoe / 4U - yoe / 100U + doy; return era * 146097 + (time_t)doe - 719468; } int64_t timeutil_timegm64(const struct tm *tm) { int64_t y = 1900 + (int64_t)tm->tm_year; unsigned int m = tm->tm_mon + 1; unsigned int d = tm->tm_mday - 1; int64_t ndays = time_days_from_civil(y, m, d); int64_t time = tm->tm_sec; time += 60LL * (tm->tm_min + 60LL * tm->tm_hour); time += 86400LL * ndays; return time; } time_t timeutil_timegm(const struct tm *tm) { int64_t time = timeutil_timegm64(tm); time_t rv = (time_t)time; errno = 0; if ((sizeof(rv) == sizeof(int32_t)) && ((time < (int64_t)INT32_MIN) || (time > (int64_t)INT32_MAX))) { errno = ERANGE; rv = -1; } return rv; } int timeutil_sync_state_update(struct timeutil_sync_state *tsp, const struct timeutil_sync_instant *inst) { int rv = -EINVAL; if (((tsp->base.ref == 0) && (inst->ref > 0)) || ((inst->ref > tsp->base.ref) && (inst->local > tsp->base.local))) { if (tsp->base.ref == 0) { tsp->base = *inst; tsp->latest = (struct timeutil_sync_instant){}; tsp->skew = 1.0f; rv = 0; } else { tsp->latest = *inst; rv = 1; } } return rv; } int timeutil_sync_state_set_skew(struct timeutil_sync_state *tsp, float skew, const struct timeutil_sync_instant *base) { int rv = -EINVAL; if (skew > 0) { tsp->skew = skew; if (base != NULL) { tsp->base = *base; tsp->latest = (struct timeutil_sync_instant){}; } rv = 0; } return rv; } float timeutil_sync_estimate_skew(const struct timeutil_sync_state *tsp) { float rv = 0; if ((tsp->base.ref != 0) && (tsp->latest.ref != 0) && (tsp->latest.local > tsp->base.local)) { const struct timeutil_sync_config *cfg = tsp->cfg; double ref_delta = tsp->latest.ref - tsp->base.ref; double local_delta = tsp->latest.local - tsp->base.local; rv = ref_delta * cfg->local_Hz / local_delta / cfg->ref_Hz; } return rv; } int timeutil_sync_ref_from_local(const struct timeutil_sync_state *tsp, uint64_t local, uint64_t *refp) { int rv = -EINVAL; if ((tsp->skew > 0) && (tsp->base.ref > 0) && (refp != NULL)) { const struct timeutil_sync_config *cfg = tsp->cfg; int64_t local_delta = local - tsp->base.local; /* (x * 1.0) != x for large values of x. * Therefore only apply the multiplication if the skew is not one. */ if (tsp->skew != 1.0f) { local_delta *= (double)tsp->skew; } int64_t ref_delta = local_delta * cfg->ref_Hz / cfg->local_Hz; int64_t ref_abs = (int64_t)tsp->base.ref + ref_delta; if (ref_abs < 0) { rv = -ERANGE; } else { *refp = ref_abs; rv = (int)(tsp->skew != 1.0f); } } return rv; } int timeutil_sync_local_from_ref(const struct timeutil_sync_state *tsp, uint64_t ref, int64_t *localp) { int rv = -EINVAL; if ((tsp->skew > 0) && (tsp->base.ref > 0) && (localp != NULL)) { const struct timeutil_sync_config *cfg = tsp->cfg; int64_t ref_delta = (int64_t)(ref - tsp->base.ref); /* (x / 1.0) != x for large values of x. * Therefore only apply the division if the skew is not one. */ int64_t local_delta = (ref_delta * cfg->local_Hz) / cfg->ref_Hz; if (tsp->skew != 1.0f) { local_delta /= (double)tsp->skew; } int64_t local_abs = (int64_t)tsp->base.local + (int64_t)local_delta; *localp = local_abs; rv = (int)(tsp->skew != 1.0f); } return rv; } int32_t timeutil_sync_skew_to_ppb(float skew) { int64_t ppb64 = (int64_t)((1.0 - (double)skew) * 1E9); int32_t ppb32 = (int32_t)ppb64; return (ppb64 == ppb32) ? ppb32 : INT32_MIN; }