diff options
Diffstat (limited to 'src/shared')
-rw-r--r-- | src/shared/calendarspec.c | 927 | ||||
-rw-r--r-- | src/shared/calendarspec.h | 57 |
2 files changed, 984 insertions, 0 deletions
diff --git a/src/shared/calendarspec.c b/src/shared/calendarspec.c new file mode 100644 index 0000000000..3cddb0eed0 --- /dev/null +++ b/src/shared/calendarspec.c @@ -0,0 +1,927 @@ +/*-*- 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" + +static void free_chain(CalendarComponent *c) { + CalendarComponent *n; + + while (c) { + n = c->next; + free(c); + c = n; + } +} + +void calendar_spec_free(CalendarSpec *c) { + assert(c); + + 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 >= 127) + 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; +} + +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; +} + +bool calendar_spec_valid(CalendarSpec *c) { + assert(c); + + if (c->weekdays_bits > 127) + 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 <= 127); + + 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 <= 127) { + 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 = NULL; + + *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 (strcasecmp(p, "hourly") == 0) { + r = const_chain(0, &c->minute); + if (r < 0) + goto fail; + r = const_chain(0, &c->second); + if (r < 0) + goto fail; + + } else if (strcasecmp(p, "daily") == 0) { + 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 (strcasecmp(p, "monthly") == 0) { + 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 (strcasecmp(p, "weekly") == 0) { + + 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 { + 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; + 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 >= 127) + 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; +} diff --git a/src/shared/calendarspec.h b/src/shared/calendarspec.h new file mode 100644 index 0000000000..7baf318249 --- /dev/null +++ b/src/shared/calendarspec.h @@ -0,0 +1,57 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + 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/>. +***/ + +/* A structure for specifying (possibly repetitive) points in calendar + * time, a la cron */ + +#include <stdbool.h> +#include "util.h" + +typedef struct CalendarComponent { + int value; + int repeat; + + struct CalendarComponent *next; +} CalendarComponent; + +typedef struct CalendarSpec { + int weekdays_bits; + + CalendarComponent *year; + CalendarComponent *month; + CalendarComponent *day; + + CalendarComponent *hour; + CalendarComponent *minute; + CalendarComponent *second; +} CalendarSpec; + +void calendar_spec_free(CalendarSpec *c); + +int calendar_spec_normalize(CalendarSpec *spec); +bool calendar_spec_valid(CalendarSpec *spec); + +int calendar_spec_to_string(const CalendarSpec *spec, char **p); +int calendar_spec_from_string(const char *p, CalendarSpec **spec); + +int calendar_spec_next_usec(const CalendarSpec *spec, usec_t usec, usec_t *next); |