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mirror of https://gitlab.nic.cz/labs/bird.git synced 2024-12-23 02:01:55 +00:00
bird/lib/bitmap.c
Maria Matejka 8d1215dba6 Channel: Refeeding by an auxiliary request if needed.
If the protocol supports route refresh on export, we keep the stop-start
method of route refeed. This applies for BGP with ERR or with export
table on, for OSPF, Babel, RIP or Pipe.

For BGP without ERR or for future selective ROA reloads, we're adding an
auxiliary export request, doing the refeed while the main export request
is running, somehow resembling the original method of BIRD 2 refeed.

There is also a refeed request queue to keep track of different refeed
requests.
2023-10-03 09:54:39 +02:00

200 lines
3.2 KiB
C

/*
* BIRD Library -- Bitmaps
*
* (c) 2019 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2019 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/bitmap.h"
#include "lib/bitops.h"
#include "lib/resource.h"
/*
* Basic bitmap
*/
void
bmap_init(struct bmap *b, pool *p, uint size)
{
b->size = BIRD_ALIGN(size, 4);
b->data = mb_allocz(p, b->size);
}
void
bmap_reset(struct bmap *b, uint size)
{
b->size = BIRD_ALIGN(size, 4);
memset(b->data, 0, b->size);
}
void
bmap_grow(struct bmap *b, uint need)
{
ASSERT_DIE(b->size);
uint size = b->size * 2;
while (size < need)
size *= 2;
uint old_size = b->size;
b->size = size;
b->data = mb_realloc(b->data, b->size);
ASSERT(size >= old_size);
memset(b->data + (old_size / 4), 0, size - old_size);
}
void
bmap_free(struct bmap *b)
{
mb_free(b->data);
b->size = 0;
b->data = NULL;
}
/*
* Hierarchical bitmap
*/
#define B256_SIZE(b) BIRD_ALIGN(b, 32)
#define B256_STEP(b) (BIRD_ALIGN(b, 8192) >> 8)
void
hmap_init(struct hmap *b, pool *p, uint size)
{
b->size[0] = B256_SIZE(size);
b->size[1] = B256_STEP(b->size[0]);
b->size[2] = B256_STEP(b->size[1]);
b->size[3] = sizeof(b->root);
b->data[0] = mb_allocz(p, b->size[0]);
b->data[1] = mb_allocz(p, b->size[1]);
b->data[2] = mb_allocz(p, b->size[2]);
b->data[3] = b->root;
memset(b->root, 0, sizeof(b->root));
}
static void
hmap_grow(struct hmap *b, uint need)
{
uint size = b->size[0] * 2;
while (size < need)
size *= 2;
for (uint i = 0; i < 3; i++)
{
uint old_size = b->size[i];
b->size[i] = size;
b->data[i] = mb_realloc(b->data[i], b->size[i]);
ASSERT(size >= old_size);
memset(b->data[i] + (old_size / 4), 0, size - old_size);
size = B256_STEP(size);
}
}
void
hmap_free(struct hmap *b)
{
mb_free(b->data[0]);
mb_free(b->data[1]);
mb_free(b->data[2]);
memset(b, 0, sizeof(struct hmap));
}
static inline int
b256_and(u32 *p)
{
for (int i = 0; i < 8; i++)
if (~p[i])
return 0;
return 1;
}
void
hmap_set(struct hmap *b, uint n)
{
if (n >= hmap_max(b))
hmap_grow(b, n/8 + 1);
for (int i = 0; i < 4; i++)
{
BIT32_SET(b->data[i], n);
n = n >> 8;
/* Continue if all bits in 256-bit block are set */
if (! b256_and(b->data[i] + 8*n))
break;
}
}
void
hmap_clear(struct hmap *b, uint n)
{
if (n >= hmap_max(b))
return;
for (int i = 0; i < 4; i++)
{
BIT32_CLR(b->data[i], n);
n = n >> 8;
}
}
static inline int
b256_first_zero(u32 *p)
{
for (int i = 0; i < 8; i++)
if (~p[i])
return 32*i + u32_ctz(~p[i]);
return 256;
}
u32
hmap_first_zero(struct hmap *b)
{
u32 n = 0;
for (int i = 3; i >= 0; i--)
{
if (32*n >= b->size[i])
return hmap_max(b);
u32 *p = b->data[i] + 8*n;
n = (n << 8) + b256_first_zero(p);
}
return n;
}
void
hmap_check(struct hmap *b)
{
for (int i = 0; i < 2; i++)
{
int max = b->size[i] / 32;
for (int j = 0; j < max; j++)
{
int x = b256_and(b->data[i] + 8*j);
int y = !!BIT32_TEST(b->data[i+1], j);
if (x != y)
bug("Inconsistent data on %d:%d (%d vs %d)", i, j, x, y);
}
}
}