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Diffstat (limited to 'lib/dtotimespec.c')
-rw-r--r-- | lib/dtotimespec.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/lib/dtotimespec.c b/lib/dtotimespec.c new file mode 100644 index 0000000..40adbe5 --- /dev/null +++ b/lib/dtotimespec.c @@ -0,0 +1,53 @@ +/* Convert double to timespec. + + Copyright (C) 2011-2020 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* written by Paul Eggert */ + +/* Convert the double value SEC to a struct timespec. Round toward + positive infinity. On overflow, return an extremal value. */ + +#include <config.h> + +#include "timespec.h" + +#include "intprops.h" + +struct timespec +dtotimespec (double sec) +{ + if (! (TYPE_MINIMUM (time_t) < sec)) + return make_timespec (TYPE_MINIMUM (time_t), 0); + else if (! (sec < 1.0 + TYPE_MAXIMUM (time_t))) + return make_timespec (TYPE_MAXIMUM (time_t), TIMESPEC_HZ - 1); + else + { + time_t s = sec; + double frac = TIMESPEC_HZ * (sec - s); + long ns = frac; + ns += ns < frac; + s += ns / TIMESPEC_HZ; + ns %= TIMESPEC_HZ; + + if (ns < 0) + { + s--; + ns += TIMESPEC_HZ; + } + + return make_timespec (s, ns); + } +} |