mirror of
https://gitlab.nic.cz/labs/bird.git
synced 2024-11-09 12:48:43 +00:00
77 lines
1.3 KiB
C
77 lines
1.3 KiB
C
/*
|
|
* BIRD Library -- ID Map
|
|
*
|
|
* (c) 2013--2015 Ondrej Zajicek <santiago@crfreenet.org>
|
|
* (c) 2013--2015 CZ.NIC z.s.p.o.
|
|
*
|
|
* Can be freely distributed and used under the terms of the GNU GPL.
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
|
|
#include "nest/bird.h"
|
|
#include "lib/idm.h"
|
|
#include "lib/resource.h"
|
|
#include "lib/string.h"
|
|
|
|
|
|
void
|
|
idm_init(struct idm *m, pool *p, uint size)
|
|
{
|
|
m->pos = 0;
|
|
m->used = 1;
|
|
m->size = size;
|
|
m->data = mb_allocz(p, m->size * sizeof(u32));
|
|
|
|
/* ID 0 is reserved */
|
|
m->data[0] = 1;
|
|
}
|
|
|
|
static inline int u32_cto(uint x) { return ffs(~x) - 1; }
|
|
|
|
u32
|
|
idm_alloc(struct idm *m)
|
|
{
|
|
uint i, j;
|
|
|
|
for (i = m->pos; i < m->size; i++)
|
|
if (m->data[i] != 0xffffffff)
|
|
goto found;
|
|
|
|
/* If we are at least 7/8 full, expand */
|
|
if (m->used > (m->size * 28))
|
|
{
|
|
m->size *= 2;
|
|
m->data = mb_realloc(m->data, m->size * sizeof(u32));
|
|
memset(m->data + i, 0, (m->size - i) * sizeof(u32));
|
|
goto found;
|
|
}
|
|
|
|
for (i = 0; i < m->pos; i++)
|
|
if (m->data[i] != 0xffffffff)
|
|
goto found;
|
|
|
|
ASSERT(0);
|
|
|
|
found:
|
|
ASSERT(i < 0x8000000);
|
|
|
|
m->pos = i;
|
|
j = u32_cto(m->data[i]);
|
|
|
|
m->data[i] |= (1 << j);
|
|
m->used++;
|
|
return 32 * i + j;
|
|
}
|
|
|
|
void
|
|
idm_free(struct idm *m, u32 id)
|
|
{
|
|
uint i = id / 32;
|
|
uint j = id % 32;
|
|
|
|
ASSERT((i < m->size) && (m->data[i] & (1 << j)));
|
|
m->data[i] &= ~(1 << j);
|
|
m->used--;
|
|
}
|