odyssey/sources/id.c

/*
 * Odissey.
 *
 * Advanced PostgreSQL connection pooler.
*/

#include <stdlib.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include <time.h>
#include <signal.h>

#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/tcp.h>
#include <netdb.h>

#include <machinarium.h>
#include <shapito.h>

#include "sources/macro.h"
#include "sources/atomic.h"
#include "sources/util.h"
#include "sources/pid.h"
#include "sources/id.h"
#include "sources/logger.h"

void od_idmgr_init(od_idmgr_t *mgr)
{
	memset(&mgr->rand_state, 0, sizeof(mgr->rand_state));
}

int od_idmgr_seed(od_idmgr_t *mgr)
{
	struct timeval tv;
	gettimeofday(&tv, NULL);

	long int rand_seed_2 = 0;
	long int rand_seed;
	rand_seed = getpid() ^ getuid() ^ tv.tv_sec ^ tv.tv_usec;

	int fd;
	fd = open("/dev/random", O_RDONLY);
	if (fd == -1)
		fd = open("/dev/urandom", O_RDONLY);
	if (fd != -1) {
		read(fd, &rand_seed_2, sizeof(rand_seed_2));
		close(fd);
	}

	rand_seed ^= rand_seed_2;
	srand48_r(rand_seed, &mgr->rand_state);
	return 0;
}

void od_idmgr_generate(od_idmgr_t *mgr, od_id_t *id, char *prefix)
{
	long int a, b;
	lrand48_r(&mgr->rand_state, &a);
	lrand48_r(&mgr->rand_state, &b);

	char seed[OD_ID_SEEDMAX];
	memcpy(seed + 0, &a, 4);
	memcpy(seed + 4, &b, 2);

	id->id_prefix = prefix;
	id->id_a = a;
	id->id_b = b;

	static const char *hex = "0123456789abcdef";
	int q, w;
	for (q = 0, w = 0; q < OD_ID_SEEDMAX; q++) {
		id->id[w++] = hex[(seed[q] >> 4) & 0x0F];
		id->id[w++] = hex[(seed[q]     ) & 0x0F];
	}
	assert(w == (OD_ID_SEEDMAX * 2));
}