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#include "mimedefang.h"
#include <pthread.h>
/* Our identifiers are in base-60 */
#define BASE 60
/* Our time-based identifier is 5 base-60 characters.
TIMESPAN below is 60^5 */
#define TIMESPAN (BASE*BASE*BASE*BASE*BASE)
#define COUNTER_MOD (BASE*BASE)
/* Counter incremented each time gen_id is called */
static unsigned int id_counter = 0;
/* Mutext to protext id_counter */
static pthread_mutex_t id_counter_mutex = PTHREAD_MUTEX_INITIALIZER;
/* This had better be 60 characters long! */
static char const char_map[BASE] = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWX";
char *
gen_mx_id(char *out)
{
unsigned int counter, time_part;
int i;
pthread_mutex_lock(&id_counter_mutex);
counter = id_counter++;
pthread_mutex_unlock(&id_counter_mutex);
time_part = ((unsigned int) time(NULL)) % TIMESPAN;
for (i=4; i>=0; i--) {
out[i] = char_map[time_part % BASE];
time_part /= BASE;
}
for (i=6; i>=5; i--) {
out[i] = char_map[counter % BASE];
counter /= BASE;
}
out[MX_ID_LEN] = 0;
return out;
}
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