#include <string.h>

#include <sys/types.h>

#include <sys/time.h>

#include <time.h>

#include <stdlib.h>

#include <stdio.h>

struct time_state

};

struct cron_spec

};

unsigned short mon_end_days[] =

{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

unsigned short mon_start_ydays[] =

{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};

unsigned short leap_mon_end_days[] =

{31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

unsigned short leap_mon_start_ydays[] =

{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335};

int field_cmp(int , int);

struct timeval * next_timeout(struct timeval *, struct time_state *);

int day_field_cmp(struct time_state *, struct time_state *);

int dow(int y, int m, int d);

int leap_year(int);

struct timeval * next_start(struct timeval *, struct cron_spec *);

int

main()

{

struct cron_spec test_spec;

memset(&test_spec, 0, sizeof(test_spec));

test_spec.sec[10] = 1;

test_spec.sec_flag = 1;

test_spec.min[3] = 1;

test_spec.min[45] = 1;

test_spec.min_flag = 1;

test_spec.hour[11] = 1;

test_spec.hour_flag = 1;

test_spec.mday[15] = 1;

test_spec.mday_flag = 1;

test_spec.mon[6] = 1;

test_spec.mon[9] = 1;

test_spec.mon[2] = 1;

test_spec.mon_flag = 1;

test_spec.wday[4] = 1;

test_spec.wday_flag = 1;

struct timeval now;

gettimeofday(&now, 0);

struct timeval * timeout;

timeout = next_start(&now, &test_spec);

for(int i = 0; i < 1000; i++)

{

struct timeval t;

if (timeout)

{

t = *timeout;

free(timeout);

}

timeout = next_start(&t, &test_spec);

}

return 0;

}

struct timeline_tree_mon

{

unsigned char days[32];

};

struct timeline_tree

};

void

init_timeline(struct timeline_tree * t_line, struct cron_spec * n)

{

unsigned int cur[6];

memset(&cur, 0, sizeof(cur));

int year = t_line->year;

memset(t_line, 0, sizeof(*t_line));

t_line->year = year;

unsigned short * days_in_month;

unsigned char active_mon[12];

if (t_line->year == 0)

{

if (n->year > 0)

t_line->year = n->year - 1900;

else

{

struct timeval now;

gettimeofday(&now, 0);

struct tm * g = gmtime(&now.tv_sec);

t_line->year = g->tm_year;

}

}

if(leap_year(t_line->year + 1900))

days_in_month = leap_mon_end_days;

else

days_in_month = mon_end_days;

memset(active_mon, 0, sizeof(active_mon));

if (n->mon_flag)

{

for(int i = 0; i < 12; i++)

{

if (n->mon[i])

active_mon[i] = 1;

}

}

else

{

for(int i = 0; i < 12; i++) active_mon[i] = 1;

}

if (n->mday_flag)

{

int mon = 0;

int md = 1;

for(int i = 0; i < 366; i++,md++)

{

if (md > days_in_month[mon])

{

mon++;

md = 1;

}

if (mon < 12)

{

if (n->mday[md])

{

if (active_mon[mon])

{

t_line->yday[i] = 1;

t_line->mday[i] = md;

t_line->mon[i] = mon;

}

}

}

}

}

if (n->wday_flag)

{

int mon = 0;

int w_d = dow(t_line->year + 1900, 1, 1);

int md = 1;

for(int i = 0; i < 366; i++, w_d++, md++)

{

if (w_d > 6)

w_d = 0;

if (md > days_in_month[mon])

{

mon++;

md = 1;

}

if (mon < 12)

{

if (n->wday[w_d])

{

if (active_mon[mon])

{

t_line->yday[i] = 1;

t_line->mday[i] = md;

t_line->mon[i] = mon;

}

}

}

}

}

if ((n->wday_flag == 0) && (n->mday_flag == 0))

{

int mon = 0;

int md = 1;

for(int i = 0; i < 366; i++)

{

if (active_mon[mon])

{

t_line->yday[i] = 1;

}

md++;

if (md > days_in_month[mon])

{

mon++;

md = 1;

}

}

}

if (n->hour_flag)

{

for(int i = 0; i < 24; i++)

{

if (n->hour[i])

t_line->hour[i] = 1;

}

}

else

{

for(int i = 0; i < 24; i++)

t_line->hour[i] = 1;

}

if (n->min_flag)

{

for(int i = i; i < 60; i++)

{

if (n->min[i])

t_line->min[i] = 1;

}

}

else

{

for(int i = 0; i < 60; i++)

t_line->min[i] = 1;

}

if (n->sec_flag)

{

for(int i = 0; i < 60; i++)

{

if (n->sec[i])

t_line->sec[i] = 1;

}

}

else

{

for(int i = 0; i < 60; i++)

t_line->sec[i] = 1;

}

}

struct timeval *

next_start(struct timeval * c, struct cron_spec * n)

{

struct timeline_tree tline;

memset(&tline, 0, sizeof(tline));

struct tm * t_now = gmtime(&c->tv_sec);

struct time_state * s = malloc(sizeof(*s));

s->sec = t_now->tm_sec;

s->min = t_now->tm_min;

s->hour = t_now->tm_hour;

s->mday = t_now->tm_mday;

s->mon = t_now->tm_mon;

s->year = t_now->tm_year;

s->wday = t_now->tm_wday;

s->yday = t_now->tm_yday;

tline.year = s->year;

struct time_state cur;

memset(&cur, 0, sizeof(cur));

cur.year = tline.year;

while(1)

{

init_timeline(&tline, n);

if ((n->year > 0) & (s->year > n->year)) return 0;

int i;

cur.yday = s->yday;

while(1)

{

for(i = cur.yday; (i < 366) & (tline.yday[i] == 0); i++);

if (i >= 366) break;

else if (i > s->yday)

{

s->hour = 0;

s->min = 0;

s->sec = 0;

}

cur.yday = i;

cur.hour = s->hour;

while(1)

{

for (i = cur.hour; (i < 24) & (tline.hour[i] == 0); i++);

if (i >= 24) break;

else if (i > s->hour)

{

s->min = 0;

s->sec = 0;

}

cur.hour = i;

cur.min = s->min;

while(1)

{

for(i = cur.min; (i < 60) & (tline.min[i] == 0); i++);

if (i >= 60) break;

else if (i > s->min)

{

s->sec = 0;

}

cur.min = i;

cur.sec = s->sec;

while(1)

{

for(i = cur.sec; (i < 60) & (tline.sec[i] == 0); i++);

if (i >= 60) break;

cur.sec = i;

struct tm t_out;

memset(&t_out, 0, sizeof(t_out));

t_out.tm_sec = cur.sec;

t_out.tm_min = cur.min;

t_out.tm_hour = cur.hour;

t_out.tm_mday = tline.mday[cur.yday];

t_out.tm_mon = tline.mon[cur.yday];

t_out.tm_year = tline.year;

struct timeval * tval_out = malloc(sizeof(*tval_out));

tval_out->tv_sec = mktime(&t_out);

tval_out->tv_usec = 0;

if (tval_out->tv_sec <= c->tv_sec)

{

cur.sec++;

}

else

{

printf("found date -- %d %d %d %d:%d:%d -- yday %d\n", tline.year + 1900, tline.mon[cur.yday],

tline.mday[cur.yday], cur.hour, cur.min, cur.sec, cur.yday);

free(s);

return tval_out;

}

}

cur.min++;

}

cur.hour++;

}

cur.yday++;

}

tline.year++;

if ((tline.year + 1900) > 2037 ) break;

cur.year = tline.year;

memset(s, 0, sizeof(*s));

s->year = tline.year;

}

free(s);

return 0;

}

int dow(int y, int m, int d)

{

static int t[] = {0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4};

y -= m < 3;

return (y + y/4 - y/100 + y/400 + t[m-1] + d) % 7;

}

int

leap_year(int y)

{

if (y % 4)

return 0;

else if (y % 100)

return 1;

else if (y % 400)

return 0;

else

return 1;

}