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bird/lib/bitmap.c
Ondrej Zajicek e338c4b63c Lib: Extend MPLS label allocator bitmap
Add function lmap_last_one_in_range() for finding the last active label
in a label range.
2023-10-04 13:07:33 +02:00

487 lines
7.8 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)
{
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);
}
}
}
/*
* Indirect bitmap for MPLS labels (20 bit range)
*/
void
lmap_init(struct lmap *b, pool *p)
{
b->slab = sl_new(p, 128);
b->size = 8;
b->data = mb_allocz(p, b->size * sizeof(u32 *));
b->root = sl_allocz(b->slab);
}
static void
lmap_grow(struct lmap *b, uint need)
{
uint old_size = b->size;
while (b->size < need)
b->size *= 2;
b->data = mb_realloc(b->data, b->size * sizeof(u32 *));
memset(b->data + old_size, 0, (b->size - old_size) * sizeof(u32 *));
}
void
lmap_free(struct lmap *b)
{
rfree(b->slab);
mb_free(b->data);
memset(b, 0, sizeof(struct lmap));
}
static inline int
b1024_and(u32 *p)
{
for (int i = 0; i < 32; i++)
if (~p[i])
return 0;
return 1;
}
static inline int
b1024_or(u32 *p)
{
for (int i = 0; i < 32; i++)
if (p[i])
return 1;
return 0;
}
int
lmap_test(struct lmap *b, uint n)
{
uint n0 = n >> 10;
uint n1 = n & 0x3ff;
return (n0 < b->size) && b->data[n0] && BIT32_TEST(b->data[n0], n1);
}
void
lmap_set(struct lmap *b, uint n)
{
uint n0 = n >> 10;
uint n1 = n & 0x3ff;
if (n0 >= b->size)
lmap_grow(b, n0 + 1);
if (! b->data[n0])
b->data[n0] = sl_allocz(b->slab);
BIT32_SET(b->data[n0], n1);
if (b1024_and(b->data[n0]))
BIT32_SET(b->root, n0);
}
void
lmap_clear(struct lmap *b, uint n)
{
uint n0 = n >> 10;
uint n1 = n & 0x3ff;
if (n0 >= b->size)
return;
if (! b->data[n0])
return;
BIT32_CLR(b->data[n0], n1);
BIT32_CLR(b->root, n0);
if (!b1024_or(b->data[n0]))
{
sl_free(b->data[n0]);
b->data[n0] = NULL;
}
}
static inline int
b1024_first_zero(u32 *p)
{
for (int i = 0; i < 32; i++)
if (~p[i])
return 32*i + u32_ctz(~p[i]);
return 1024;
}
uint
lmap_first_zero(struct lmap *b)
{
uint n0 = b1024_first_zero(b->root);
uint n1 = ((n0 < b->size) && b->data[n0]) ?
b1024_first_zero(b->data[n0]) : 0;
return (n0 << 10) + n1;
}
static uint
b1024_first_zero_in_range(u32 *p, uint lo, uint hi)
{
uint lo0 = lo >> 5;
uint lo1 = lo & 0x1f;
uint hi0 = hi >> 5;
uint hi1 = hi & 0x1f;
u32 mask = (1 << lo1) - 1;
u32 val;
for (uint i = lo0; i < hi0; i++)
{
val = p[i] | mask;
mask = 0;
if (~val)
return 32*i + u32_ctz(~val);
}
if (hi1)
{
mask |= ~((1u << hi1) - 1);
val = p[hi0] | mask;
if (~val)
return 32*hi0 + u32_ctz(~val);
}
return hi;
}
uint
lmap_first_zero_in_range(struct lmap *b, uint lo, uint hi)
{
uint lo0 = lo >> 10;
uint lo1 = lo & 0x3ff;
uint hi0 = hi >> 10;
uint hi1 = hi & 0x3ff;
if (lo1)
{
uint max = (lo0 == hi0) ? hi1 : 1024;
uint n0 = lo0;
uint n1 = ((n0 < b->size) && b->data[n0]) ?
b1024_first_zero_in_range(b->data[n0], lo1, max) : lo1;
if (n1 < 1024)
return (n0 << 10) + n1;
lo0++;
lo1 = 0;
}
if (lo0 < hi0)
{
uint n0 = b1024_first_zero_in_range(b->root, lo0, hi0);
if (n0 < hi0)
{
uint n1 = ((n0 < b->size) && b->data[n0]) ?
b1024_first_zero(b->data[n0]) : 0;
return (n0 << 10) + n1;
}
}
if (hi1)
{
uint n0 = hi0;
uint n1 = ((n0 < b->size) && b->data[n0]) ?
b1024_first_zero_in_range(b->data[n0], 0, hi1) : 0;
return (n0 << 10) + n1;
}
return hi;
}
static inline int
b1024_last_one(u32 *p)
{
for (int i = 31; i >= 0; i--)
if (p[i])
return 32*i + (31 - u32_clz(p[i]));
return 1024;
}
static uint
b1024_last_one_in_range(u32 *p, uint lo, uint hi)
{
uint lo0 = lo >> 5;
uint lo1 = lo & 0x1f;
uint hi0 = hi >> 5;
uint hi1 = hi & 0x1f;
u32 mask = (1u << hi1) - 1;
u32 val;
for (int i = hi0; i > (int) lo0; i--)
{
val = p[i] & mask;
mask = ~0;
if (val)
return 32*i + (31 - u32_clz(val));
}
{
mask &= ~((1u << lo1) - 1);
val = p[lo0] & mask;
if (val)
return 32*lo0 + (31 - u32_clz(val));
}
return hi;
}
uint
lmap_last_one_in_range(struct lmap *b, uint lo, uint hi)
{
uint lo0 = lo >> 10;
uint lo1 = lo & 0x3ff;
uint hi0 = hi >> 10;
uint hi1 = hi & 0x3ff;
if (hi1 && (hi0 < b->size) && b->data[hi0])
{
uint min = (lo0 == hi0) ? lo1 : 0;
uint n0 = hi0;
uint n1 = b1024_last_one_in_range(b->data[n0], min, hi1);
if (n1 < hi1)
return (n0 << 10) + n1;
}
for (int i = (int)MIN(hi0, b->size) - 1; i >= (int) lo0; i--)
{
if (! b->data[i])
continue;
uint n0 = i;
uint n1 = b1024_last_one(b->data[n0]);
if ((n0 == lo0) && (n1 < lo1))
return hi;
return (n0 << 10) + n1;
}
return hi;
}
void
lmap_check(struct lmap *b)
{
for (int i = 0; i < (int) b->size; i++)
{
int x = b->data[i] && b1024_and(b->data[i]);
int y = !!BIT32_TEST(b->root, i);
if (x != y)
bug("Inconsistent data on %d (%d vs %d)", i, x, y);
}
}