cdesktopenv/cde/lib/DtMmdb/misc/unique_id.c

217 lines
5.9 KiB
C

/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they 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 these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/* Copyright (c) 1994 FUJITSU LIMITED */
/* All Rights Reserved */
/*
* $XConsortium: unique_id.c /main/3 1996/06/11 17:40:45 cde-hal $
*
* Copyright (c) 1992 HAL Computer Systems International, Ltd.
* All rights reserved. Unpublished -- rights reserved under
* the Copyright Laws of the United States. USE OF A COPYRIGHT
* NOTICE IS PRECAUTIONARY ONLY AND DOES NOT IMPLY PUBLICATION
* OR DISCLOSURE.
*
* THIS SOFTWARE CONTAINS CONFIDENTIAL INFORMATION AND TRADE
* SECRETS OF HAL COMPUTER SYSTEMS INTERNATIONAL, LTD. USE,
* DISCLOSURE, OR REPRODUCTION IS PROHIBITED WITHOUT THE
* PRIOR EXPRESS WRITTEN PERMISSION OF HAL COMPUTER SYSTEMS
* INTERNATIONAL, LTD.
*
* RESTRICTED RIGHTS LEGEND
* Use, duplication, or disclosure by the Government is subject
* to the restrictions as set forth in subparagraph (c)(l)(ii)
* of the Rights in Technical Data and Computer Software clause
* at DFARS 252.227-7013.
*
* HAL COMPUTER SYSTEMS INTERNATIONAL, LTD.
* 1315 Dell Avenue
* Campbell, CA 95008
*
*/
#include <sys/types.h>
#include <sys/time.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <ctype.h>
#ifdef SVR4
#include <sys/systeminfo.h>
#endif
/* **************************************************************
* unique_id - generate a 15 character NULL terminated id
* ************************************************************** */
/* This code assumes:
sizeof (time_t) == 4,
sizeof (int) == 4,
sizeof (short) == 2,
sizeof ("hostid") == 4,
sizeof ("pid") == 2,
*/
/* #define DEBUG */
static char mapping[] =
{ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'.', '_' };
static unsigned int mask[] =
{ 0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff };
#define COPY_BITS(DEST,DPOS,SRC,SPOS,LEN) \
DEST |= ((SRC & (mask[LEN] << SPOS)) >> SPOS) << DPOS;
#define PRINT_BITS(BITS) \
{ int i; unsigned long bits = BITS; printf (#BITS " = 0x%04x", BITS); \
for (i = 0; i < sizeof(BITS) * 8; i++, bits <<= 1) { \
if (!(i%4)) putchar (' '); \
(bits & (1L << (sizeof(BITS) * 8)-1)) ? putchar('1') : putchar('0'); } \
putchar ('\n'); }
#if defined(SVR4) && !defined(sun)
static unsigned int
gethostid()
{
char buffer[256];
sysinfo (SI_HW_SERIAL, buffer, sizeof (buffer));
return (atoi (buffer));
}
#endif
const char *
unique_id (void)
{
static char buf[16];
static unsigned int hostid;
static struct timeval cur_time, old_time;
static unsigned short pid;
static int i;
/* -------- First get the information -------- */
/* Loop until first char is alpha-numeric. */
do
{
/* Loop over time until unique. */
do
{
/* Failure of this call is catastrophic: */
if (gettimeofday (&cur_time, NULL) == -1)
{
perror ("unique_id:gettimeofday");
abort();
}
/* Truncate microseconds to milliseconds. */
cur_time.tv_usec /= 1000;
}
while (cur_time.tv_usec == old_time.tv_usec &&
cur_time.tv_sec == old_time.tv_sec);
old_time.tv_usec = cur_time.tv_usec;
old_time.tv_sec = cur_time.tv_sec;
if (pid == 0)
pid = getpid();
if (hostid == 0)
hostid = gethostid();
#ifdef DEBUG
PRINT_BITS ((unsigned int)cur_time.tv_usec);
PRINT_BITS ((unsigned int)cur_time.tv_sec);
PRINT_BITS (pid);
PRINT_BITS (hostid);
#endif
for (i = 0; i < 15; i++)
buf[i] = 0;
COPY_BITS (buf[0], 0, cur_time.tv_usec, 0, 6);
COPY_BITS (buf[1], 0, cur_time.tv_usec, 6, 4);
COPY_BITS (buf[1], 4, cur_time.tv_sec, 0, 2);
COPY_BITS (buf[2], 0, cur_time.tv_sec, 2, 6);
COPY_BITS (buf[3], 0, cur_time.tv_sec, 8, 6);
COPY_BITS (buf[4], 0, cur_time.tv_sec, 14, 6);
COPY_BITS (buf[5], 0, cur_time.tv_sec, 20, 6);
COPY_BITS (buf[6], 0, cur_time.tv_sec, 26, 6);
COPY_BITS (buf[7], 0, pid, 0, 6);
COPY_BITS (buf[8], 0, pid, 6, 6);
COPY_BITS (buf[9], 0, pid, 12, 4);
COPY_BITS (buf[9], 4, hostid, 0, 2);
COPY_BITS (buf[10], 0, hostid, 2, 6);
COPY_BITS (buf[11], 0, hostid, 8, 6);
COPY_BITS (buf[12], 0, hostid, 14, 6);
COPY_BITS (buf[13], 0, hostid, 20, 6);
COPY_BITS (buf[14], 0, hostid, 26, 6);
for (i = 0; i < 15; i++)
{
#ifdef DEBUG
unsigned char ch = buf[i];
printf ("%2d 0x%02x ", i, ch);
PRINT_BITS (ch);
#endif
buf[i] = mapping[(int)buf[i]];
}
} while (!isalnum ((unsigned char) buf[0]));
return (buf);
}
#ifdef TEST
int
main (int argc, char **argv)
{
int count = 0;
int i;
if (argc == 1)
count = 1;
else if (argc == 2)
count = atoi (argv[1]);
if (count == 0)
{
printf (stderr, "usage: uid [count]");
exit (1);
}
printf ("Generating %d unique ids\n", count);
for (i = 0; i < count; i++)
puts (unique_id());
}
#endif /* TEST */