diff mbox

[dpdk-dev,3/7] member: implement vBF mode

Message ID 1503361193-36699-4-git-send-email-yipeng1.wang@intel.com (mailing list archive)
State Superseded, archived
Headers show

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Wang, Yipeng1 Aug. 22, 2017, 12:19 a.m. UTC
Bloom Filter (BF) [1] is a well-known space-efficient
probabilistic data structure that answers set membership queries.
Vector of Bloom Filters (vBF) is an extension to traditional BF
that supports multi-set membership testing. Traditional BF will
return found or not-found for each key. vBF will also return
which set the key belongs to if it is found.

Since each set requires a BF, vBF should be used when set count
is small. vBF's false positive rate could be set arbitrarily so
that its memory requirement and lookup speed is better in certain
cases comparing to HT based set-summary.

This patch adds the vBF implementation.

[1]B H Bloom, “Space/Time Trade-offs in Hash Coding with Allowable
Errors,” Communications of the ACM, 1970.

Signed-off-by: Yipeng Wang <yipeng1.wang@intel.com>
---
 lib/librte_member/Makefile         |   2 +-
 lib/librte_member/rte_member_vbf.c | 309 +++++++++++++++++++++++++++++++++++++
 lib/librte_member/rte_member_vbf.h |  85 ++++++++++
 3 files changed, 395 insertions(+), 1 deletion(-)
 create mode 100644 lib/librte_member/rte_member_vbf.c
 create mode 100644 lib/librte_member/rte_member_vbf.h
diff mbox

Patch

diff --git a/lib/librte_member/Makefile b/lib/librte_member/Makefile
index 110e4be..90bdfe8 100644
--- a/lib/librte_member/Makefile
+++ b/lib/librte_member/Makefile
@@ -41,7 +41,7 @@  EXPORT_MAP := rte_member_version.map
 LIBABIVER := 1
 
 # all source are stored in SRCS-y
-SRCS-$(CONFIG_RTE_LIBRTE_MEMBER) +=  rte_member.c rte_member_ht.c
+SRCS-$(CONFIG_RTE_LIBRTE_MEMBER) +=  rte_member.c rte_member_ht.c rte_member_vbf.c
 # install includes
 SYMLINK-$(CONFIG_RTE_LIBRTE_MEMBER)-include := rte_member.h
 
diff --git a/lib/librte_member/rte_member_vbf.c b/lib/librte_member/rte_member_vbf.c
new file mode 100644
index 0000000..90c10ea
--- /dev/null
+++ b/lib/librte_member/rte_member_vbf.c
@@ -0,0 +1,309 @@ 
+/*-
+ *   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 > 32 || !rte_is_power_of_2(params->num_set)) {
+		rte_errno = EINVAL;
+		RTE_LOG(ERR, MEMBER, "vBF create with invalid parameters\n");
+	}
+
+	/* We assume expected keys evenly distribute to all BFs */
+	uint32_t num_keys_per_bf = (params->num_keys + ss->num_set - 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 need to be
+	 * calculated.
+	 * Assume each BF's False positive rate is x. The total false positive
+	 * rate is fp = 1-(1-x)^n.
+	 * => x = 1 - (1-fp)^(1/n)
+	 */
+
+	float x = 1 - pow((1 - params->false_positive_rate), 1.0 / ss->num_set);
+
+	uint32_t bits = ceil((num_keys_per_bf *
+				log(x)) / 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;
+
+	ss->table = rte_zmalloc_socket(NULL, sizeof(uint32_t) * ss->num_set *
+			(ss->bits >> 5), RTE_CACHE_LINE_SIZE, ss->socket_id);
+
+
+	/*
+	 * 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);
+
+	RTE_LOG(DEBUG, MEMBER, "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, x, new_fp);
+
+	if (ss->table == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+
+/*
+ * a is how many bits could be represented by one uint32_t variable.
+ * b is used for division shift
+ * shift is used for multiplication shift
+ */
+static inline uint32_t
+test_bit(uint32_t h1, uint32_t h2, uint32_t iter, uint32_t shift, uint32_t a,
+		uint32_t b, const struct rte_member_setsum *ss)
+{
+	uint32_t *vbf = ss->table;
+	uint32_t n = ss->num_set;
+	uint32_t bit_loc = (h1 + iter * h2) & ss->bit_mask;
+	/*
+	 * 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>>b] >> ((bit_loc & (a - 1)) << shift)) &
+							((1ULL << n) - 1);
+}
+
+
+static inline void
+set_bit(uint32_t h1, uint32_t h2, uint32_t iter, uint32_t shift, uint32_t a,
+		uint32_t b, const struct rte_member_setsum *ss, int32_t set)
+{
+	uint32_t *vbf = ss->table;
+	uint32_t bit_loc = (h1 + iter * h2) & ss->bit_mask;
+	vbf[bit_loc>>b] |= 1U << (((bit_loc & (a - 1)) << shift) + set - 1);
+}
+
+
+
+int
+rte_member_lookup_vbf(const struct rte_member_setsum *ss, const void *key,
+		MEMBER_SET_TYPE *set_id)
+{
+	uint32_t j;
+	uint32_t h1 = MEMBER_PRIM_HASH(key, ss->key_len, ss->prim_hash_seed);
+	uint32_t h2 = MEMBER_SEC_HASH(&h1, 4, ss->sec_hash_seed);
+	uint32_t mask = 0xFFFFFFFF;
+	uint32_t shift = __builtin_ctz(ss->num_set);
+	uint32_t a = 32 >> shift;
+	uint32_t b = __builtin_ctz(a);
+
+	for (j = 0; j < ss->num_hashes; j++)
+		mask &= test_bit(h1, h2, j, shift, a, b, ss);
+
+	if (mask) {
+		*set_id = __builtin_ctz(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_TYPE *set_ids)
+{
+	uint32_t i, k, h1, h2;
+	uint32_t ret = 0;
+	uint32_t mask;
+	uint32_t shift = __builtin_ctz(ss->num_set);
+	uint32_t a = 32 >> shift;
+	uint32_t b = __builtin_ctz(a);
+
+	for (i = 0; i < num_keys; i++) {
+		mask = 0xFFFFFFFF;
+		h1 = MEMBER_PRIM_HASH(keys[i], ss->key_len,
+					ss->prim_hash_seed);
+		h2 = MEMBER_SEC_HASH(&h1, 4, ss->sec_hash_seed);
+		for (k = 0; k < ss->num_hashes; k++)
+			mask &= test_bit(h1, h2, k, shift, a, b, ss);
+
+		if (mask) {
+			set_ids[i] = __builtin_ctz(mask) + 1;
+			ret++;
+		} else
+			set_ids[i] = RTE_MEMBER_NO_MATCH;
+	}
+	return ret;
+}
+
+
+
+uint32_t
+rte_member_lookup_multi_vbf(const struct rte_member_setsum *ss,
+		const void *key, uint32_t match_per_key,
+		MEMBER_SET_TYPE *set_id)
+{
+	uint32_t ret = 0;
+	uint32_t j;
+	uint32_t h1 = MEMBER_PRIM_HASH(key, ss->key_len, ss->prim_hash_seed);
+	uint32_t h2 = MEMBER_SEC_HASH(&h1, 4, ss->sec_hash_seed);
+	uint32_t mask = 0xFFFFFFFF;
+	uint32_t shift = __builtin_ctz(ss->num_set);
+	uint32_t a = 32 >> shift;
+	uint32_t b = __builtin_ctz(a);
+
+	for (j = 0; j < ss->num_hashes; j++)
+		mask &= test_bit(h1, h2, j, shift, a, b, ss);
+
+	while (mask) {
+		uint32_t loc = __builtin_ctz(mask);
+		set_id[ret] = loc + 1;
+		ret++;
+		if (ret >= match_per_key)
+			return ret;
+		mask &= ~(1U << loc);
+	}
+	return ret;
+}
+
+
+
+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_TYPE *set_ids)
+{
+	uint32_t i, k, h1, h2;
+	uint32_t ret = 0;
+	uint32_t match_cnt_t;
+	uint32_t mask;
+	uint32_t shift = __builtin_ctz(ss->num_set);
+	uint32_t a = 32 >> shift;
+	uint32_t b = __builtin_ctz(a);
+
+	for (i = 0; i < num_keys; i++) {
+		match_cnt_t = 0;
+		mask = 0xFFFFFFFF;
+		h1 = MEMBER_PRIM_HASH(keys[i], ss->key_len,
+					ss->prim_hash_seed);
+		h2 = MEMBER_SEC_HASH(&h1, 4, ss->sec_hash_seed);
+
+		for (k = 0; k < ss->num_hashes; k++)
+			mask &= test_bit(h1, h2, k, shift, a, b, ss);
+
+		while (mask) {
+			uint32_t loc = __builtin_ctz(mask);
+			if (match_cnt_t >= match_per_key)
+				break;
+			set_ids[i * match_per_key + match_cnt_t] = loc + 1;
+			match_cnt_t++;
+			mask &= ~(1U << loc);
+		}
+		match_count[i] = match_cnt_t;
+		if (match_cnt_t != 0)
+			ret++;
+	}
+	return ret;
+}
+
+
+int
+rte_member_add_vbf(const struct rte_member_setsum *ss,
+		const void *key, MEMBER_SET_TYPE set_id)
+{
+	uint32_t i, h1, h2;
+
+	if (set_id > ss->num_set || set_id == RTE_MEMBER_NO_MATCH)
+		return -EINVAL;
+
+	h1 = MEMBER_PRIM_HASH(key, ss->key_len, ss->prim_hash_seed);
+	h2 = MEMBER_SEC_HASH(&h1, 4, ss->sec_hash_seed);
+	uint32_t shift = __builtin_ctz(ss->num_set);
+	uint32_t a = 32 >> shift;
+	uint32_t b = __builtin_ctz(a);
+
+	for (i = 0; i < ss->num_hashes; i++)
+		set_bit(h1, h2, i, shift, a, b, 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);
+}
diff --git a/lib/librte_member/rte_member_vbf.h b/lib/librte_member/rte_member_vbf.h
new file mode 100644
index 0000000..3d3ee33
--- /dev/null
+++ b/lib/librte_member/rte_member_vbf.h
@@ -0,0 +1,85 @@ 
+/*-
+ *   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.
+ */
+
+#ifndef _RTE_MEMBER_VBF_H_
+#define _RTE_MEMBER_VBF_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int
+rte_member_create_vbf(struct rte_member_setsum *ss,
+		const struct rte_member_parameters *params);
+
+
+int
+rte_member_lookup_vbf(const struct rte_member_setsum *setsum,
+		const void *key, MEMBER_SET_TYPE *set_id);
+
+
+uint32_t
+rte_member_lookup_bulk_vbf(const struct rte_member_setsum *setsum,
+		const void **keys, uint32_t num_keys,
+		MEMBER_SET_TYPE *set_ids);
+
+
+uint32_t
+rte_member_lookup_multi_vbf(const struct rte_member_setsum *setsum,
+		const void *key, uint32_t match_per_key,
+		MEMBER_SET_TYPE *set_id);
+
+
+uint32_t
+rte_member_lookup_multi_bulk_vbf(const struct rte_member_setsum *setsum,
+		const void **keys, uint32_t num_keys, uint32_t match_per_key,
+		uint32_t *match_count,
+		MEMBER_SET_TYPE *set_ids);
+
+int
+rte_member_add_vbf(const struct rte_member_setsum *setsum,
+		const void *key, MEMBER_SET_TYPE set_id);
+
+void
+rte_member_free_vbf(struct rte_member_setsum *ss);
+
+
+void
+rte_member_reset_vbf(const struct rte_member_setsum *setsum);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_MEMBER_VBF_H_ */