calendarspec.c revision a095315b3c31f7a419baceac82c26c3c5ac0cd12
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2012 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <stdlib.h>
#include <string.h>
#include "calendarspec.h"
#define BITS_WEEKDAYS 127
static void free_chain(CalendarComponent *c) {
CalendarComponent *n;
while (c) {
n = c->next;
free(c);
c = n;
}
}
void calendar_spec_free(CalendarSpec *c) {
if (!c)
return;
free_chain(c->year);
free_chain(c->month);
free_chain(c->day);
free_chain(c->hour);
free_chain(c->minute);
free_chain(c->second);
free(c);
}
static int component_compare(const void *_a, const void *_b) {
CalendarComponent * const *a = _a, * const *b = _b;
if ((*a)->value < (*b)->value)
return -1;
if ((*a)->value > (*b)->value)
return 1;
if ((*a)->repeat < (*b)->repeat)
return -1;
if ((*a)->repeat > (*b)->repeat)
return 1;
return 0;
}
static void sort_chain(CalendarComponent **c) {
unsigned n = 0, k;
CalendarComponent **b, *i, **j, *next;
assert(c);
for (i = *c; i; i = i->next)
n++;
if (n <= 1)
return;
j = b = alloca(sizeof(CalendarComponent*) * n);
for (i = *c; i; i = i->next)
*(j++) = i;
qsort(b, n, sizeof(CalendarComponent*), component_compare);
b[n-1]->next = NULL;
next = b[n-1];
/* Drop non-unique entries */
for (k = n-1; k > 0; k--) {
if (b[k-1]->value == next->value &&
b[k-1]->repeat == next->repeat) {
free(b[k-1]);
continue;
}
b[k-1]->next = next;
next = b[k-1];
}
*c = next;
}
static void fix_year(CalendarComponent *c) {
/* Turns 12 → 2012, 89 → 1989 */
while(c) {
CalendarComponent *n = c->next;
if (c->value >= 0 && c->value < 70)
c->value += 2000;
if (c->value >= 70 && c->value < 100)
c->value += 1900;
c = n;
}
}
int calendar_spec_normalize(CalendarSpec *c) {
assert(c);
if (c->weekdays_bits <= 0 || c->weekdays_bits >= BITS_WEEKDAYS)
c->weekdays_bits = -1;
fix_year(c->year);
sort_chain(&c->year);
sort_chain(&c->month);
sort_chain(&c->day);
sort_chain(&c->hour);
sort_chain(&c->minute);
sort_chain(&c->second);
return 0;
}
_pure_ static bool chain_valid(CalendarComponent *c, int from, int to) {
if (!c)
return true;
if (c->value < from || c->value > to)
return false;
if (c->value + c->repeat > to)
return false;
if (c->next)
return chain_valid(c->next, from, to);
return true;
}
_pure_ bool calendar_spec_valid(CalendarSpec *c) {
assert(c);
if (c->weekdays_bits > BITS_WEEKDAYS)
return false;
if (!chain_valid(c->year, 1970, 2199))
return false;
if (!chain_valid(c->month, 1, 12))
return false;
if (!chain_valid(c->day, 1, 31))
return false;
if (!chain_valid(c->hour, 0, 23))
return false;
if (!chain_valid(c->minute, 0, 59))
return false;
if (!chain_valid(c->second, 0, 59))
return false;
return true;
}
static void format_weekdays(FILE *f, const CalendarSpec *c) {
static const char *const days[] = {
"Mon",
"Tue",
"Wed",
"Thu",
"Fri",
"Sat",
"Sun"
};
int l, x;
bool need_colon = false;
assert(f);
assert(c);
assert(c->weekdays_bits > 0 && c->weekdays_bits <= BITS_WEEKDAYS);
for (x = 0, l = -1; x < (int) ELEMENTSOF(days); x++) {
if (c->weekdays_bits & (1 << x)) {
if (l < 0) {
if (need_colon)
fputc(',', f);
else
need_colon = true;
fputs(days[x], f);
l = x;
}
} else if (l >= 0) {
if (x > l + 1) {
fputc(x > l + 2 ? '-' : ',', f);
fputs(days[x-1], f);
}
l = -1;
}
}
if (l >= 0 && x > l + 1) {
fputc(x > l + 2 ? '-' : ',', f);
fputs(days[x-1], f);
}
}
static void format_chain(FILE *f, int space, const CalendarComponent *c) {
assert(f);
if (!c) {
fputc('*', f);
return;
}
assert(c->value >= 0);
fprintf(f, "%0*i", space, c->value);
if (c->repeat > 0)
fprintf(f, "/%i", c->repeat);
if (c->next) {
fputc(',', f);
format_chain(f, space, c->next);
}
}
int calendar_spec_to_string(const CalendarSpec *c, char **p) {
char *buf = NULL;
size_t sz = 0;
FILE *f;
assert(c);
assert(p);
f = open_memstream(&buf, &sz);
if (!f)
return -ENOMEM;
if (c->weekdays_bits > 0 && c->weekdays_bits <= BITS_WEEKDAYS) {
format_weekdays(f, c);
fputc(' ', f);
}
format_chain(f, 4, c->year);
fputc('-', f);
format_chain(f, 2, c->month);
fputc('-', f);
format_chain(f, 2, c->day);
fputc(' ', f);
format_chain(f, 2, c->hour);
fputc(':', f);
format_chain(f, 2, c->minute);
fputc(':', f);
format_chain(f, 2, c->second);
fflush(f);
if (ferror(f)) {
free(buf);
fclose(f);
return -ENOMEM;
}
fclose(f);
*p = buf;
return 0;
}
static int parse_weekdays(const char **p, CalendarSpec *c) {
static const struct {
const char *name;
const int nr;
} day_nr[] = {
{ "Monday", 0 },
{ "Mon", 0 },
{ "Tuesday", 1 },
{ "Tue", 1 },
{ "Wednesday", 2 },
{ "Wed", 2 },
{ "Thursday", 3 },
{ "Thu", 3 },
{ "Friday", 4 },
{ "Fri", 4 },
{ "Saturday", 5 },
{ "Sat", 5 },
{ "Sunday", 6 },
{ "Sun", 6 }
};
int l = -1;
bool first = true;
assert(p);
assert(*p);
assert(c);
for (;;) {
unsigned i;
if (!first && **p == ' ')
return 0;
for (i = 0; i < ELEMENTSOF(day_nr); i++) {
size_t skip;
if (!startswith_no_case(*p, day_nr[i].name))
continue;
skip = strlen(day_nr[i].name);
if ((*p)[skip] != '-' &&
(*p)[skip] != ',' &&
(*p)[skip] != ' ' &&
(*p)[skip] != 0)
return -EINVAL;
c->weekdays_bits |= 1 << day_nr[i].nr;
if (l >= 0) {
int j;
if (l > day_nr[i].nr)
return -EINVAL;
for (j = l + 1; j < day_nr[i].nr; j++)
c->weekdays_bits |= 1 << j;
}
*p += skip;
break;
}
/* Couldn't find this prefix, so let's assume the
weekday was not specified and let's continue with
the date */
if (i >= ELEMENTSOF(day_nr))
return first ? 0 : -EINVAL;
/* We reached the end of the string */
if (**p == 0)
return 0;
/* We reached the end of the weekday spec part */
if (**p == ' ') {
*p += strspn(*p, " ");
return 0;
}
if (**p == '-') {
if (l >= 0)
return -EINVAL;
l = day_nr[i].nr;
} else
l = -1;
*p += 1;
first = false;
}
}
static int prepend_component(const char **p, CalendarComponent **c) {
unsigned long value, repeat = 0;
char *e = NULL, *ee = NULL;
CalendarComponent *cc;
assert(p);
assert(c);
errno = 0;
value = strtoul(*p, &e, 10);
if (errno > 0)
return -errno;
if (e == *p)
return -EINVAL;
if ((unsigned long) (int) value != value)
return -ERANGE;
if (*e == '/') {
repeat = strtoul(e+1, &ee, 10);
if (errno > 0)
return -errno;
if (ee == e+1)
return -EINVAL;
if ((unsigned long) (int) repeat != repeat)
return -ERANGE;
if (repeat <= 0)
return -ERANGE;
e = ee;
}
if (*e != 0 && *e != ' ' && *e != ',' && *e != '-' && *e != ':')
return -EINVAL;
cc = new0(CalendarComponent, 1);
if (!cc)
return -ENOMEM;
cc->value = value;
cc->repeat = repeat;
cc->next = *c;
*p = e;
*c = cc;
if (*e ==',') {
*p += 1;
return prepend_component(p, c);
}
return 0;
}
static int parse_chain(const char **p, CalendarComponent **c) {
const char *t;
CalendarComponent *cc = NULL;
int r;
assert(p);
assert(c);
t = *p;
if (t[0] == '*') {
*p = t + 1;
*c = NULL;
return 0;
}
r = prepend_component(&t, &cc);
if (r < 0) {
free_chain(cc);
return r;
}
*p = t;
*c = cc;
return 0;
}
static int const_chain(int value, CalendarComponent **c) {
CalendarComponent *cc = NULL;
assert(c);
cc = new0(CalendarComponent, 1);
if (!cc)
return -ENOMEM;
cc->value = value;
cc->repeat = 0;
cc->next = *c;
*c = cc;
return 0;
}
static int parse_date(const char **p, CalendarSpec *c) {
const char *t;
int r;
CalendarComponent *first, *second, *third;
assert(p);
assert(*p);
assert(c);
t = *p;
if (*t == 0)
return 0;
r = parse_chain(&t, &first);
if (r < 0)
return r;
/* Already the end? A ':' as separator? In that case this was a time, not a date */
if (*t == 0 || *t == ':') {
free_chain(first);
return 0;
}
if (*t != '-') {
free_chain(first);
return -EINVAL;
}
t++;
r = parse_chain(&t, &second);
if (r < 0) {
free_chain(first);
return r;
}
/* Got two parts, hence it's month and day */
if (*t == ' ' || *t == 0) {
*p = t + strspn(t, " ");
c->month = first;
c->day = second;
return 0;
}
if (*t != '-') {
free_chain(first);
free_chain(second);
return -EINVAL;
}
t++;
r = parse_chain(&t, &third);
if (r < 0) {
free_chain(first);
free_chain(second);
return r;
}
/* Got tree parts, hence it is year, month and day */
if (*t == ' ' || *t == 0) {
*p = t + strspn(t, " ");
c->year = first;
c->month = second;
c->day = third;
return 0;
}
free_chain(first);
free_chain(second);
free_chain(third);
return -EINVAL;
}
static int parse_time(const char **p, CalendarSpec *c) {
CalendarComponent *h = NULL, *m = NULL, *s = NULL;
const char *t;
int r;
assert(p);
assert(*p);
assert(c);
t = *p;
if (*t == 0) {
/* If no time is specified at all, but a date of some
* kind, then this means 00:00:00 */
if (c->day || c->weekdays_bits > 0)
goto null_hour;
goto finish;
}
r = parse_chain(&t, &h);
if (r < 0)
goto fail;
if (*t != ':') {
r = -EINVAL;
goto fail;
}
t++;
r = parse_chain(&t, &m);
if (r < 0)
goto fail;
/* Already at the end? Then it's hours and minutes, and seconds are 0 */
if (*t == 0) {
if (m != NULL)
goto null_second;
goto finish;
}
if (*t != ':') {
r = -EINVAL;
goto fail;
}
t++;
r = parse_chain(&t, &s);
if (r < 0)
goto fail;
/* At the end? Then it's hours, minutes and seconds */
if (*t == 0)
goto finish;
r = -EINVAL;
goto fail;
null_hour:
r = const_chain(0, &h);
if (r < 0)
goto fail;
r = const_chain(0, &m);
if (r < 0)
goto fail;
null_second:
r = const_chain(0, &s);
if (r < 0)
goto fail;
finish:
*p = t;
c->hour = h;
c->minute = m;
c->second = s;
return 0;
fail:
free_chain(h);
free_chain(m);
free_chain(s);
return r;
}
int calendar_spec_from_string(const char *p, CalendarSpec **spec) {
CalendarSpec *c;
int r;
assert(p);
assert(spec);
if (isempty(p))
return -EINVAL;
c = new0(CalendarSpec, 1);
if (!c)
return -ENOMEM;
if (strcaseeq(p, "minutely")) {
r = const_chain(0, &c->second);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "hourly")) {
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->second);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "daily")) {
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->second);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "monthly")) {
r = const_chain(1, &c->day);
if (r < 0)
goto fail;
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->second);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "annually") ||
strcaseeq(p, "yearly") ||
strcaseeq(p, "anually") /* backwards compatibility */ ) {
r = const_chain(1, &c->month);
if (r < 0)
goto fail;
r = const_chain(1, &c->day);
if (r < 0)
goto fail;
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->second);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "weekly")) {
c->weekdays_bits = 1;
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->second);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "quarterly")) {
r = const_chain(1, &c->month);
if (r < 0)
goto fail;
r = const_chain(4, &c->month);
if (r < 0)
goto fail;
r = const_chain(7, &c->month);
if (r < 0)
goto fail;
r = const_chain(10, &c->month);
if (r < 0)
goto fail;
r = const_chain(1, &c->day);
if (r < 0)
goto fail;
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->second);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "biannually") ||
strcaseeq(p, "bi-annually") ||
strcaseeq(p, "semiannually") ||
strcaseeq(p, "semi-annually")) {
r = const_chain(1, &c->month);
if (r < 0)
goto fail;
r = const_chain(7, &c->month);
if (r < 0)
goto fail;
r = const_chain(1, &c->day);
if (r < 0)
goto fail;
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->second);
if (r < 0)
goto fail;
} else {
r = parse_weekdays(&p, c);
if (r < 0)
goto fail;
r = parse_date(&p, c);
if (r < 0)
goto fail;
r = parse_time(&p, c);
if (r < 0)
goto fail;
if (*p != 0) {
r = -EINVAL;
goto fail;
}
}
r = calendar_spec_normalize(c);
if (r < 0)
goto fail;
if (!calendar_spec_valid(c)) {
r = -EINVAL;
goto fail;
}
*spec = c;
return 0;
fail:
calendar_spec_free(c);
return r;
}
static int find_matching_component(const CalendarComponent *c, int *val) {
const CalendarComponent *n;
int d = -1;
bool d_set = false;
int r;
assert(val);
if (!c)
return 0;
while (c) {
n = c->next;
if (c->value >= *val) {
if (!d_set || c->value < d) {
d = c->value;
d_set = true;
}
} else if (c->repeat > 0) {
int k;
k = c->value + c->repeat * ((*val - c->value + c->repeat -1) / c->repeat);
if (!d_set || k < d) {
d = k;
d_set = true;
}
}
c = n;
}
if (!d_set)
return -ENOENT;
r = *val != d;
*val = d;
return r;
}
static bool tm_out_of_bounds(const struct tm *tm) {
struct tm t;
assert(tm);
t = *tm;
if (mktime(&t) == (time_t) -1)
return true;
/* Did any normalization take place? If so, it was out of bounds before */
return
t.tm_year != tm->tm_year ||
t.tm_mon != tm->tm_mon ||
t.tm_mday != tm->tm_mday ||
t.tm_hour != tm->tm_hour ||
t.tm_min != tm->tm_min ||
t.tm_sec != tm->tm_sec;
}
static bool matches_weekday(int weekdays_bits, const struct tm *tm) {
struct tm t;
int k;
if (weekdays_bits < 0 || weekdays_bits >= BITS_WEEKDAYS)
return true;
t = *tm;
if (mktime(&t) == (time_t) -1)
return false;
k = t.tm_wday == 0 ? 6 : t.tm_wday - 1;
return (weekdays_bits & (1 << k));
}
static int find_next(const CalendarSpec *spec, struct tm *tm) {
struct tm c;
int r;
assert(spec);
assert(tm);
c = *tm;
for (;;) {
/* Normalize the current date */
mktime(&c);
c.tm_isdst = -1;
c.tm_year += 1900;
r = find_matching_component(spec->year, &c.tm_year);
c.tm_year -= 1900;
if (r > 0) {
c.tm_mon = 0;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = 0;
}
if (r < 0 || tm_out_of_bounds(&c))
return r;
c.tm_mon += 1;
r = find_matching_component(spec->month, &c.tm_mon);
c.tm_mon -= 1;
if (r > 0) {
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = 0;
}
if (r < 0 || tm_out_of_bounds(&c)) {
c.tm_year ++;
c.tm_mon = 0;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = 0;
continue;
}
r = find_matching_component(spec->day, &c.tm_mday);
if (r > 0)
c.tm_hour = c.tm_min = c.tm_sec = 0;
if (r < 0 || tm_out_of_bounds(&c)) {
c.tm_mon ++;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = 0;
continue;
}
if (!matches_weekday(spec->weekdays_bits, &c)) {
c.tm_mday++;
c.tm_hour = c.tm_min = c.tm_sec = 0;
continue;
}
r = find_matching_component(spec->hour, &c.tm_hour);
if (r > 0)
c.tm_min = c.tm_sec = 0;
if (r < 0 || tm_out_of_bounds(&c)) {
c.tm_mday ++;
c.tm_hour = c.tm_min = c.tm_sec = 0;
continue;
}
r = find_matching_component(spec->minute, &c.tm_min);
if (r > 0)
c.tm_sec = 0;
if (r < 0 || tm_out_of_bounds(&c)) {
c.tm_hour ++;
c.tm_min = c.tm_sec = 0;
continue;
}
r = find_matching_component(spec->second, &c.tm_sec);
if (r < 0 || tm_out_of_bounds(&c)) {
c.tm_min ++;
c.tm_sec = 0;
continue;
}
*tm = c;
return 0;
}
}
int calendar_spec_next_usec(const CalendarSpec *spec, usec_t usec, usec_t *next) {
struct tm tm;
time_t t;
int r;
assert(spec);
assert(next);
t = (time_t) (usec / USEC_PER_SEC) + 1;
assert_se(localtime_r(&t, &tm));
r = find_next(spec, &tm);
if (r < 0)
return r;
t = mktime(&tm);
if (t == (time_t) -1)
return -EINVAL;
*next = (usec_t) t * USEC_PER_SEC;
return 0;
}