numam-dpdk/lib/member/rte_member_vbf.c
Sean Morrissey 30a1de105a lib: remove unneeded header includes
These header includes have been flagged by the iwyu_tool
and removed.

Signed-off-by: Sean Morrissey <sean.morrissey@intel.com>
2022-02-22 13:10:39 +01:00

321 lines
8.5 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2017 Intel Corporation
*/
#include <math.h>
#include <string.h>
#include <rte_malloc.h>
#include <rte_errno.h>
#include <rte_log.h>
#include "rte_member.h"
#include "rte_member_vbf.h"
/*
* vBF currently implemented as a big array.
* The BFs have a vertical layout. Bits in same location of all bfs will stay
* in the same cache line.
* For example, if we have 32 bloom filters, we use a uint32_t array to
* represent all of them. array[0] represent the first location of all the
* bloom filters, array[1] represents the second location of all the
* bloom filters, etc. The advantage of this layout is to minimize the average
* number of memory accesses to test all bloom filters.
*
* Currently the implementation supports vBF containing 1,2,4,8,16,32 BFs.
*/
int
rte_member_create_vbf(struct rte_member_setsum *ss,
const struct rte_member_parameters *params)
{
if (params->num_set > RTE_MEMBER_MAX_BF ||
!rte_is_power_of_2(params->num_set) ||
params->num_keys == 0 ||
params->false_positive_rate == 0 ||
params->false_positive_rate > 1) {
rte_errno = EINVAL;
RTE_MEMBER_LOG(ERR, "Membership vBF create with invalid parameters\n");
return -EINVAL;
}
/* We assume expected keys evenly distribute to all BFs */
uint32_t num_keys_per_bf = 1 + (params->num_keys - 1) / ss->num_set;
/*
* Note that the false positive rate is for all BFs in the vBF
* such that the single BF's false positive rate needs to be
* calculated.
* Assume each BF's False positive rate is fp_one_bf. The total false
* positive rate is fp = 1-(1-fp_one_bf)^n.
* => fp_one_bf = 1 - (1-fp)^(1/n)
*/
float fp_one_bf = 1 - pow((1 - params->false_positive_rate),
1.0 / ss->num_set);
if (fp_one_bf == 0) {
rte_errno = EINVAL;
RTE_MEMBER_LOG(ERR, "Membership BF false positive rate is too small\n");
return -EINVAL;
}
uint32_t bits = ceil((num_keys_per_bf *
log(fp_one_bf)) /
log(1.0 / (pow(2.0, log(2.0)))));
/* We round to power of 2 for performance during lookup */
ss->bits = rte_align32pow2(bits);
ss->num_hashes = (uint32_t)(log(2.0) * bits / num_keys_per_bf);
ss->bit_mask = ss->bits - 1;
/*
* Since we round the bits to power of 2, the final false positive
* rate will probably not be same as the user specified. We log the
* new value as debug message.
*/
float new_fp = pow((1 - pow((1 - 1.0 / ss->bits), num_keys_per_bf *
ss->num_hashes)), ss->num_hashes);
new_fp = 1 - pow((1 - new_fp), ss->num_set);
/*
* Reduce hash function count, until we approach the user specified
* false-positive rate. Otherwise it is too conservative
*/
int tmp_num_hash = ss->num_hashes;
while (tmp_num_hash > 1) {
float tmp_fp = new_fp;
tmp_num_hash--;
new_fp = pow((1 - pow((1 - 1.0 / ss->bits), num_keys_per_bf *
tmp_num_hash)), tmp_num_hash);
new_fp = 1 - pow((1 - new_fp), ss->num_set);
if (new_fp > params->false_positive_rate) {
new_fp = tmp_fp;
tmp_num_hash++;
break;
}
}
ss->num_hashes = tmp_num_hash;
/*
* To avoid multiplication and division:
* mul_shift is used for multiplication shift during bit test
* div_shift is used for division shift, to be divided by number of bits
* represented by a uint32_t variable
*/
ss->mul_shift = __builtin_ctzl(ss->num_set);
ss->div_shift = __builtin_ctzl(32 >> ss->mul_shift);
RTE_MEMBER_LOG(DEBUG, "vector bloom filter created, "
"each bloom filter expects %u keys, needs %u bits, %u hashes, "
"with false positive rate set as %.5f, "
"The new calculated vBF false positive rate is %.5f\n",
num_keys_per_bf, ss->bits, ss->num_hashes, fp_one_bf, new_fp);
ss->table = rte_zmalloc_socket(NULL, ss->num_set * (ss->bits >> 3),
RTE_CACHE_LINE_SIZE, ss->socket_id);
if (ss->table == NULL)
return -ENOMEM;
return 0;
}
static inline uint32_t
test_bit(uint32_t bit_loc, const struct rte_member_setsum *ss)
{
uint32_t *vbf = ss->table;
uint32_t n = ss->num_set;
uint32_t div_shift = ss->div_shift;
uint32_t mul_shift = ss->mul_shift;
/*
* a is how many bits in one BF are represented by one 32bit
* variable.
*/
uint32_t a = 32 >> mul_shift;
/*
* x>>b is the divide, x & (a-1) is the mod, & (1<<n-1) to mask out bits
* we do not need
*/
return (vbf[bit_loc >> div_shift] >>
((bit_loc & (a - 1)) << mul_shift)) & ((1ULL << n) - 1);
}
static inline void
set_bit(uint32_t bit_loc, const struct rte_member_setsum *ss, int32_t set)
{
uint32_t *vbf = ss->table;
uint32_t div_shift = ss->div_shift;
uint32_t mul_shift = ss->mul_shift;
uint32_t a = 32 >> mul_shift;
vbf[bit_loc >> div_shift] |=
1UL << (((bit_loc & (a - 1)) << mul_shift) + set - 1);
}
int
rte_member_lookup_vbf(const struct rte_member_setsum *ss, const void *key,
member_set_t *set_id)
{
uint32_t j;
uint32_t h1 = MEMBER_HASH_FUNC(key, ss->key_len, ss->prim_hash_seed);
uint32_t h2 = MEMBER_HASH_FUNC(&h1, sizeof(uint32_t),
ss->sec_hash_seed);
uint32_t mask = ~0;
uint32_t bit_loc;
for (j = 0; j < ss->num_hashes; j++) {
bit_loc = (h1 + j * h2) & ss->bit_mask;
mask &= test_bit(bit_loc, ss);
}
if (mask) {
*set_id = __builtin_ctzl(mask) + 1;
return 1;
}
*set_id = RTE_MEMBER_NO_MATCH;
return 0;
}
uint32_t
rte_member_lookup_bulk_vbf(const struct rte_member_setsum *ss,
const void **keys, uint32_t num_keys, member_set_t *set_ids)
{
uint32_t i, k;
uint32_t num_matches = 0;
uint32_t mask[RTE_MEMBER_LOOKUP_BULK_MAX];
uint32_t h1[RTE_MEMBER_LOOKUP_BULK_MAX], h2[RTE_MEMBER_LOOKUP_BULK_MAX];
uint32_t bit_loc;
for (i = 0; i < num_keys; i++)
h1[i] = MEMBER_HASH_FUNC(keys[i], ss->key_len,
ss->prim_hash_seed);
for (i = 0; i < num_keys; i++)
h2[i] = MEMBER_HASH_FUNC(&h1[i], sizeof(uint32_t),
ss->sec_hash_seed);
for (i = 0; i < num_keys; i++) {
mask[i] = ~0;
for (k = 0; k < ss->num_hashes; k++) {
bit_loc = (h1[i] + k * h2[i]) & ss->bit_mask;
mask[i] &= test_bit(bit_loc, ss);
}
}
for (i = 0; i < num_keys; i++) {
if (mask[i]) {
set_ids[i] = __builtin_ctzl(mask[i]) + 1;
num_matches++;
} else
set_ids[i] = RTE_MEMBER_NO_MATCH;
}
return num_matches;
}
uint32_t
rte_member_lookup_multi_vbf(const struct rte_member_setsum *ss,
const void *key, uint32_t match_per_key,
member_set_t *set_id)
{
uint32_t num_matches = 0;
uint32_t j;
uint32_t h1 = MEMBER_HASH_FUNC(key, ss->key_len, ss->prim_hash_seed);
uint32_t h2 = MEMBER_HASH_FUNC(&h1, sizeof(uint32_t),
ss->sec_hash_seed);
uint32_t mask = ~0;
uint32_t bit_loc;
for (j = 0; j < ss->num_hashes; j++) {
bit_loc = (h1 + j * h2) & ss->bit_mask;
mask &= test_bit(bit_loc, ss);
}
while (mask) {
uint32_t loc = __builtin_ctzl(mask);
set_id[num_matches] = loc + 1;
num_matches++;
if (num_matches >= match_per_key)
return num_matches;
mask &= ~(1UL << loc);
}
return num_matches;
}
uint32_t
rte_member_lookup_multi_bulk_vbf(const struct rte_member_setsum *ss,
const void **keys, uint32_t num_keys, uint32_t match_per_key,
uint32_t *match_count,
member_set_t *set_ids)
{
uint32_t i, k;
uint32_t num_matches = 0;
uint32_t match_cnt_t;
uint32_t mask[RTE_MEMBER_LOOKUP_BULK_MAX];
uint32_t h1[RTE_MEMBER_LOOKUP_BULK_MAX], h2[RTE_MEMBER_LOOKUP_BULK_MAX];
uint32_t bit_loc;
for (i = 0; i < num_keys; i++)
h1[i] = MEMBER_HASH_FUNC(keys[i], ss->key_len,
ss->prim_hash_seed);
for (i = 0; i < num_keys; i++)
h2[i] = MEMBER_HASH_FUNC(&h1[i], sizeof(uint32_t),
ss->sec_hash_seed);
for (i = 0; i < num_keys; i++) {
mask[i] = ~0;
for (k = 0; k < ss->num_hashes; k++) {
bit_loc = (h1[i] + k * h2[i]) & ss->bit_mask;
mask[i] &= test_bit(bit_loc, ss);
}
}
for (i = 0; i < num_keys; i++) {
match_cnt_t = 0;
while (mask[i]) {
uint32_t loc = __builtin_ctzl(mask[i]);
set_ids[i * match_per_key + match_cnt_t] = loc + 1;
match_cnt_t++;
if (match_cnt_t >= match_per_key)
break;
mask[i] &= ~(1UL << loc);
}
match_count[i] = match_cnt_t;
if (match_cnt_t != 0)
num_matches++;
}
return num_matches;
}
int
rte_member_add_vbf(const struct rte_member_setsum *ss,
const void *key, member_set_t set_id)
{
uint32_t i, h1, h2;
uint32_t bit_loc;
if (set_id > ss->num_set || set_id == RTE_MEMBER_NO_MATCH)
return -EINVAL;
h1 = MEMBER_HASH_FUNC(key, ss->key_len, ss->prim_hash_seed);
h2 = MEMBER_HASH_FUNC(&h1, sizeof(uint32_t), ss->sec_hash_seed);
for (i = 0; i < ss->num_hashes; i++) {
bit_loc = (h1 + i * h2) & ss->bit_mask;
set_bit(bit_loc, ss, set_id);
}
return 0;
}
void
rte_member_free_vbf(struct rte_member_setsum *ss)
{
rte_free(ss->table);
}
void
rte_member_reset_vbf(const struct rte_member_setsum *ss)
{
uint32_t *vbf = ss->table;
memset(vbf, 0, (ss->num_set * ss->bits) >> 3);
}