lumiera_/src/lib/luid.c
Christian Thaeter 9826fd180d renamed the uuid to luid
uuid's are somewhat standardized, we use our uid's slightly differently,
so change the name not to be confused with standards.
 * Small fix for luid generation
 * build a 'luidgen' tool which will be used by the interface gen later
 * add emacs vars
 * include the luidgen tool in automake
2008-08-10 12:18:20 +02:00

113 lines
2.5 KiB
C

/*
luid - Lumiera unique identifiers
Copyright (C) Lumiera.org
2008, Christian Thaeter <ct@pipapo.org>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "lib/luid.h"
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdint.h>
void
lumiera_uid_set_ptr (lumiera_uid* luid, void* ptr)
{
memset (luid, 0, 16);
*(void**)luid = ptr;
}
void*
lumiera_uid_ptr_get (lumiera_uid* luid)
{
return *(void**)luid;
}
void
lumiera_uid_gen (lumiera_uid* luid)
{
static int fd = -2;
if (!luid)
return;
if (fd == -2)
{
fd = open ("/dev/urandom", O_RDONLY);
/* on linux /dev/random would be way to slow for our purpose, so we comment that out for now.
other unixiods offer a /dev/random which has the same semantics as linux /dev/urandom has,
configuration should do this right some day.
if (fd == -1)
fd = open ("/dev/random", O_RDONLY);
*/
if (fd >= 0)
fcntl (fd, F_SETFD, FD_CLOEXEC);
else
srand (getpid () + time (NULL));
}
do
{
if (fd < 0)
{
for (int i = 0; i < 16; ++i)
((unsigned char*)luid)[i] = (unsigned char)(rand()>>7);
}
else
{
if (read (fd, luid, 16) < 16)
abort ();
}
}
/* we identify generic pointers by having some zeros in the luid,
* this happens very unlikely to be in a random luid, just regenerate it then */
while (!*(((intptr_t*)luid)+1));
}
void
lumiera_uid_copy (lumiera_uid* dest, lumiera_uid* src)
{
memcpy (dest, src, 16);
}
int
lumiera_uid_eq (lumiera_uid* luida, lumiera_uid* luidb)
{
return !memcmp (luida, luidb, 16);
}
size_t
lumiera_uid_hash (lumiera_uid* luid)
{
return *(size_t*)luid;
}
/*
// Local Variables:
// mode: C
// c-file-style: "gnu"
// indent-tabs-mode: nil
// End:
*/