--- /dev/null
+/*-
+ * BSD LICENSE
+ *
+ * Copyright(c) 2017 Intel Corporation. All rights reserved.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <math.h>
+#include <string.h>
+
+#include <rte_malloc.h>
+#include <rte_memory.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);
+}
Code Review / deb_dpdk.git / blobdiff