From: "Garima Singh via GitGitGadget" <gitgitgadget@gmail.com> To: git@vger.kernel.org Cc: stolee@gmail.com, szeder.dev@gmail.com, jonathantanmy@google.com, Garima Singh <garima.singh@microsoft.com>, Garima Singh <garima.singh@microsoft.com> Subject: [PATCH v3 02/16] bloom.c: add the murmur3 hash implementation Date: Mon, 30 Mar 2020 00:31:24 +0000 [thread overview] Message-ID: <a5aa3415c05ee9bc67a9471445a20c71a9834673.1585528298.git.gitgitgadget@gmail.com> (raw) In-Reply-To: <pull.497.v3.git.1585528298.gitgitgadget@gmail.com> From: Garima Singh <garima.singh@microsoft.com> In preparation for computing changed paths Bloom filters, implement the Murmur3 hash algorithm as described in [1]. It hashes the given data using the given seed and produces a uniformly distributed hash value. [1] https://en.wikipedia.org/wiki/MurmurHash#Algorithm Helped-by: Derrick Stolee <dstolee@microsoft.com> Helped-by: Szeder Gábor <szeder.dev@gmail.com> Reviewed-by: Jakub Narębski <jnareb@gmail.com> Signed-off-by: Garima Singh <garima.singh@microsoft.com> --- Makefile | 2 ++ bloom.c | 73 +++++++++++++++++++++++++++++++++++++++++++ bloom.h | 13 ++++++++ t/helper/test-bloom.c | 13 ++++++++ t/helper/test-tool.c | 1 + t/helper/test-tool.h | 1 + t/t0095-bloom.sh | 30 ++++++++++++++++++ 7 files changed, 133 insertions(+) create mode 100644 bloom.c create mode 100644 bloom.h create mode 100644 t/helper/test-bloom.c create mode 100755 t/t0095-bloom.sh diff --git a/Makefile b/Makefile index ef1ff2228f0..491f75e68c5 100644 --- a/Makefile +++ b/Makefile @@ -695,6 +695,7 @@ X = PROGRAMS += $(patsubst %.o,git-%$X,$(PROGRAM_OBJS)) TEST_BUILTINS_OBJS += test-advise.o +TEST_BUILTINS_OBJS += test-bloom.o TEST_BUILTINS_OBJS += test-chmtime.o TEST_BUILTINS_OBJS += test-config.o TEST_BUILTINS_OBJS += test-ctype.o @@ -840,6 +841,7 @@ LIB_OBJS += base85.o LIB_OBJS += bisect.o LIB_OBJS += blame.o LIB_OBJS += blob.o +LIB_OBJS += bloom.o LIB_OBJS += branch.o LIB_OBJS += bulk-checkin.o LIB_OBJS += bundle.o diff --git a/bloom.c b/bloom.c new file mode 100644 index 00000000000..40e87632aeb --- /dev/null +++ b/bloom.c @@ -0,0 +1,73 @@ +#include "git-compat-util.h" +#include "bloom.h" + +static uint32_t rotate_left(uint32_t value, int32_t count) +{ + uint32_t mask = 8 * sizeof(uint32_t) - 1; + count &= mask; + return ((value << count) | (value >> ((-count) & mask))); +} + +/* + * Calculate the murmur3 32-bit hash value for the given data + * using the given seed. + * Produces a uniformly distributed hash value. + * Not considered to be cryptographically secure. + * Implemented as described in https://en.wikipedia.org/wiki/MurmurHash#Algorithm + */ +uint32_t murmur3_seeded(uint32_t seed, const char *data, size_t len) +{ + const uint32_t c1 = 0xcc9e2d51; + const uint32_t c2 = 0x1b873593; + const uint32_t r1 = 15; + const uint32_t r2 = 13; + const uint32_t m = 5; + const uint32_t n = 0xe6546b64; + int i; + uint32_t k1 = 0; + const char *tail; + + int len4 = len / sizeof(uint32_t); + + uint32_t k; + for (i = 0; i < len4; i++) { + uint32_t byte1 = (uint32_t)data[4*i]; + uint32_t byte2 = ((uint32_t)data[4*i + 1]) << 8; + uint32_t byte3 = ((uint32_t)data[4*i + 2]) << 16; + uint32_t byte4 = ((uint32_t)data[4*i + 3]) << 24; + k = byte1 | byte2 | byte3 | byte4; + k *= c1; + k = rotate_left(k, r1); + k *= c2; + + seed ^= k; + seed = rotate_left(seed, r2) * m + n; + } + + tail = (data + len4 * sizeof(uint32_t)); + + switch (len & (sizeof(uint32_t) - 1)) { + case 3: + k1 ^= ((uint32_t)tail[2]) << 16; + /*-fallthrough*/ + case 2: + k1 ^= ((uint32_t)tail[1]) << 8; + /*-fallthrough*/ + case 1: + k1 ^= ((uint32_t)tail[0]) << 0; + k1 *= c1; + k1 = rotate_left(k1, r1); + k1 *= c2; + seed ^= k1; + break; + } + + seed ^= (uint32_t)len; + seed ^= (seed >> 16); + seed *= 0x85ebca6b; + seed ^= (seed >> 13); + seed *= 0xc2b2ae35; + seed ^= (seed >> 16); + + return seed; +} \ No newline at end of file diff --git a/bloom.h b/bloom.h new file mode 100644 index 00000000000..d0fcc5f0aa6 --- /dev/null +++ b/bloom.h @@ -0,0 +1,13 @@ +#ifndef BLOOM_H +#define BLOOM_H + +/* + * Calculate the murmur3 32-bit hash value for the given data + * using the given seed. + * Produces a uniformly distributed hash value. + * Not considered to be cryptographically secure. + * Implemented as described in https://en.wikipedia.org/wiki/MurmurHash#Algorithm + */ +uint32_t murmur3_seeded(uint32_t seed, const char *data, size_t len); + +#endif \ No newline at end of file diff --git a/t/helper/test-bloom.c b/t/helper/test-bloom.c new file mode 100644 index 00000000000..60ee2043689 --- /dev/null +++ b/t/helper/test-bloom.c @@ -0,0 +1,13 @@ +#include "git-compat-util.h" +#include "bloom.h" +#include "test-tool.h" + +int cmd__bloom(int argc, const char **argv) +{ + if (!strcmp(argv[1], "get_murmur3")) { + uint32_t hashed = murmur3_seeded(0, argv[2], strlen(argv[2])); + printf("Murmur3 Hash with seed=0:0x%08x\n", hashed); + } + + return 0; +} \ No newline at end of file diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c index 31eedcd241f..6e26bd65c97 100644 --- a/t/helper/test-tool.c +++ b/t/helper/test-tool.c @@ -15,6 +15,7 @@ struct test_cmd { static struct test_cmd cmds[] = { { "advise", cmd__advise_if_enabled }, + { "bloom", cmd__bloom }, { "chmtime", cmd__chmtime }, { "config", cmd__config }, { "ctype", cmd__ctype }, diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h index 4eb5e6609e1..dceeef1d5c2 100644 --- a/t/helper/test-tool.h +++ b/t/helper/test-tool.h @@ -5,6 +5,7 @@ #include "git-compat-util.h" int cmd__advise_if_enabled(int argc, const char **argv); +int cmd__bloom(int argc, const char **argv); int cmd__chmtime(int argc, const char **argv); int cmd__config(int argc, const char **argv); int cmd__ctype(int argc, const char **argv); diff --git a/t/t0095-bloom.sh b/t/t0095-bloom.sh new file mode 100755 index 00000000000..2dad8c4a94e --- /dev/null +++ b/t/t0095-bloom.sh @@ -0,0 +1,30 @@ +#!/bin/sh + +test_description='Testing the various Bloom filter computations in bloom.c' +. ./test-lib.sh + +test_expect_success 'compute unseeded murmur3 hash for empty string' ' + cat >expect <<-\EOF && + Murmur3 Hash with seed=0:0x00000000 + EOF + test-tool bloom get_murmur3 "" >actual && + test_cmp expect actual +' + +test_expect_success 'compute unseeded murmur3 hash for test string 1' ' + cat >expect <<-\EOF && + Murmur3 Hash with seed=0:0x627b0c2c + EOF + test-tool bloom get_murmur3 "Hello world!" >actual && + test_cmp expect actual +' + +test_expect_success 'compute unseeded murmur3 hash for test string 2' ' + cat >expect <<-\EOF && + Murmur3 Hash with seed=0:0x2e4ff723 + EOF + test-tool bloom get_murmur3 "The quick brown fox jumps over the lazy dog" >actual && + test_cmp expect actual +' + +test_done \ No newline at end of file -- gitgitgadget
next prev parent reply other threads:[~2020-03-30 0:31 UTC|newest] Thread overview: 159+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-12-20 22:05 [PATCH 0/9] [RFC] Changed Paths Bloom Filters Garima Singh via GitGitGadget 2019-12-20 22:05 ` [PATCH 1/9] commit-graph: add --changed-paths option to write Garima Singh via GitGitGadget 2020-01-01 20:20 ` Jakub Narebski 2019-12-20 22:05 ` [PATCH 2/9] commit-graph: write changed paths bloom filters Garima Singh via GitGitGadget 2019-12-21 16:48 ` Philip Oakley 2020-01-06 18:44 ` Jakub Narebski 2020-01-13 19:48 ` Garima Singh 2019-12-20 22:05 ` [PATCH 3/9] commit-graph: use MAX_NUM_CHUNKS Garima Singh via GitGitGadget 2020-01-07 12:19 ` Jakub Narebski 2019-12-20 22:05 ` [PATCH 4/9] commit-graph: document bloom filter format Garima Singh via GitGitGadget 2020-01-07 14:46 ` Jakub Narebski 2019-12-20 22:05 ` [PATCH 5/9] commit-graph: write changed path bloom filters to commit-graph file Garima Singh via GitGitGadget 2020-01-07 16:01 ` Jakub Narebski 2020-01-14 15:14 ` Garima Singh 2019-12-20 22:05 ` [PATCH 6/9] commit-graph: test commit-graph write --changed-paths Garima Singh via GitGitGadget 2020-01-08 0:32 ` Jakub Narebski 2019-12-20 22:05 ` [PATCH 7/9] commit-graph: reuse existing bloom filters during write Garima Singh via GitGitGadget 2020-01-09 19:12 ` Jakub Narebski 2019-12-20 22:05 ` [PATCH 8/9] revision.c: use bloom filters to speed up path based revision walks Garima Singh via GitGitGadget 2020-01-11 0:27 ` Jakub Narebski 2020-01-15 0:08 ` Garima Singh 2019-12-20 22:05 ` [PATCH 9/9] commit-graph: add GIT_TEST_COMMIT_GRAPH_BLOOM_FILTERS test flag Garima Singh via GitGitGadget 2020-01-11 19:56 ` Jakub Narebski 2020-01-15 0:55 ` Garima Singh 2019-12-20 22:14 ` [PATCH 0/9] [RFC] Changed Paths Bloom Filters Junio C Hamano 2019-12-22 9:26 ` Christian Couder 2019-12-22 9:38 ` Jeff King 2020-01-01 12:04 ` Jakub Narebski 2019-12-22 9:30 ` Jeff King 2019-12-22 9:32 ` [PATCH 1/3] commit-graph: examine changed-path objects in pack order Jeff King 2019-12-27 14:51 ` Derrick Stolee 2019-12-29 6:12 ` Jeff King 2019-12-29 6:28 ` Jeff King 2019-12-30 14:37 ` Derrick Stolee 2019-12-30 14:51 ` Derrick Stolee 2019-12-22 9:32 ` [PATCH 2/3] commit-graph: free large diffs, too Jeff King 2019-12-27 14:52 ` Derrick Stolee 2019-12-22 9:32 ` [PATCH 3/3] commit-graph: stop using full rev_info for diffs Jeff King 2019-12-27 14:53 ` Derrick Stolee 2019-12-26 14:21 ` [PATCH 0/9] [RFC] Changed Paths Bloom Filters Derrick Stolee 2019-12-29 6:03 ` Jeff King 2019-12-27 16:11 ` Derrick Stolee 2019-12-29 6:24 ` Jeff King 2019-12-30 16:04 ` Derrick Stolee 2019-12-30 17:02 ` Junio C Hamano 2019-12-31 16:45 ` Jakub Narebski 2020-01-13 16:54 ` Garima Singh 2020-01-20 13:48 ` Jakub Narebski 2020-01-21 16:14 ` Garima Singh 2020-02-02 18:43 ` Jakub Narebski 2020-01-21 23:40 ` Emily Shaffer 2020-01-27 18:24 ` Garima Singh 2020-02-01 23:32 ` Jakub Narebski 2020-02-05 22:56 ` [PATCH v2 00/11] " Garima Singh via GitGitGadget 2020-02-05 22:56 ` [PATCH v2 01/11] commit-graph: use MAX_NUM_CHUNKS Garima Singh via GitGitGadget 2020-02-09 12:39 ` Jakub Narebski 2020-02-05 22:56 ` [PATCH v2 02/11] bloom: core Bloom filter implementation for changed paths Garima Singh via GitGitGadget 2020-02-15 17:17 ` Jakub Narebski 2020-02-16 16:49 ` Jakub Narebski 2020-02-22 0:32 ` Garima Singh 2020-02-23 13:38 ` Jakub Narebski 2020-02-24 17:34 ` Garima Singh 2020-02-24 18:20 ` Jakub Narebski 2020-02-05 22:56 ` [PATCH v2 03/11] diff: halt tree-diff early after max_changes Derrick Stolee via GitGitGadget 2020-02-17 0:00 ` Jakub Narebski 2020-02-22 0:37 ` Garima Singh 2020-02-05 22:56 ` [PATCH v2 04/11] commit-graph: compute Bloom filters for changed paths Garima Singh via GitGitGadget 2020-02-17 21:56 ` Jakub Narebski 2020-02-22 0:55 ` Garima Singh 2020-02-23 17:34 ` Jakub Narebski 2020-02-05 22:56 ` [PATCH v2 05/11] commit-graph: examine changed-path objects in pack order Jeff King via GitGitGadget 2020-02-18 17:59 ` Jakub Narebski 2020-02-24 18:29 ` Garima Singh 2020-02-05 22:56 ` [PATCH v2 06/11] commit-graph: examine commits by generation number Derrick Stolee via GitGitGadget 2020-02-19 0:32 ` Jakub Narebski 2020-02-24 20:45 ` Garima Singh 2020-02-05 22:56 ` [PATCH v2 07/11] commit-graph: write Bloom filters to commit graph file Garima Singh via GitGitGadget 2020-02-19 15:13 ` Jakub Narebski 2020-02-24 21:14 ` Garima Singh 2020-02-25 11:40 ` Jakub Narebski 2020-02-25 15:58 ` Garima Singh 2020-02-05 22:56 ` [PATCH v2 08/11] commit-graph: reuse existing Bloom filters during write Garima Singh via GitGitGadget 2020-02-20 18:48 ` Jakub Narebski 2020-02-24 21:45 ` Garima Singh 2020-02-05 22:56 ` [PATCH v2 09/11] commit-graph: add --changed-paths option to write subcommand Garima Singh via GitGitGadget 2020-02-20 20:28 ` Jakub Narebski 2020-02-24 21:51 ` Garima Singh 2020-02-25 12:10 ` Jakub Narebski 2020-02-20 22:10 ` Bryan Turner 2020-02-22 1:44 ` Garima Singh 2020-02-05 22:56 ` [PATCH v2 10/11] revision.c: use Bloom filters to speed up path based revision walks Garima Singh via GitGitGadget 2020-02-21 17:31 ` Jakub Narebski 2020-02-21 22:45 ` Jakub Narebski 2020-02-05 22:56 ` [PATCH v2 11/11] commit-graph: add GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS test flag Garima Singh via GitGitGadget 2020-02-22 0:11 ` Jakub Narebski 2020-02-07 13:52 ` [PATCH v2 00/11] Changed Paths Bloom Filters SZEDER Gábor 2020-02-07 15:09 ` Garima Singh 2020-02-07 15:36 ` Derrick Stolee 2020-02-07 16:15 ` SZEDER Gábor 2020-02-07 16:33 ` Derrick Stolee 2020-02-11 19:08 ` Garima Singh 2020-02-08 23:04 ` Jakub Narebski 2020-02-21 17:41 ` Garima Singh 2020-03-29 18:36 ` Junio C Hamano 2020-03-30 0:31 ` [PATCH v3 00/16] " Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 01/16] commit-graph: define and use MAX_NUM_CHUNKS Garima Singh via GitGitGadget 2020-03-30 0:31 ` Garima Singh via GitGitGadget [this message] 2020-03-30 0:31 ` [PATCH v3 03/16] bloom.c: introduce core Bloom filter constructs Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 04/16] bloom.c: core Bloom filter implementation for changed paths Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 05/16] diff: halt tree-diff early after max_changes Derrick Stolee via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 06/16] commit-graph: compute Bloom filters for changed paths Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 07/16] commit-graph: examine changed-path objects in pack order Jeff King via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 08/16] commit-graph: examine commits by generation number Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 09/16] diff: skip batch object download when possible Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 10/16] commit-graph: write Bloom filters to commit graph file Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 11/16] commit-graph: reuse existing Bloom filters during write Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 12/16] commit-graph: add --changed-paths option to write subcommand Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 13/16] revision.c: use Bloom filters to speed up path based revision walks Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 14/16] revision.c: add trace2 stats around Bloom filter usage Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 15/16] t4216: add end to end tests for git log with Bloom filters Garima Singh via GitGitGadget 2020-03-30 0:31 ` [PATCH v3 16/16] commit-graph: add GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS test flag Garima Singh via GitGitGadget 2020-04-06 16:59 ` [PATCH v4 00/15] Changed Paths Bloom Filters Garima Singh via GitGitGadget 2020-04-06 16:59 ` [PATCH v4 01/15] commit-graph: define and use MAX_NUM_CHUNKS Garima Singh via GitGitGadget 2020-04-06 16:59 ` [PATCH v4 02/15] bloom.c: add the murmur3 hash implementation Garima Singh via GitGitGadget 2020-04-06 16:59 ` [PATCH v4 03/15] bloom.c: introduce core Bloom filter constructs Garima Singh via GitGitGadget 2020-04-06 16:59 ` [PATCH v4 04/15] bloom.c: core Bloom filter implementation for changed paths Garima Singh via GitGitGadget 2020-06-27 15:53 ` SZEDER Gábor 2020-04-06 16:59 ` [PATCH v4 05/15] diff: halt tree-diff early after max_changes Derrick Stolee via GitGitGadget 2020-08-04 14:47 ` SZEDER Gábor 2020-08-04 16:25 ` Derrick Stolee 2020-08-04 17:00 ` SZEDER Gábor 2020-08-04 17:31 ` Derrick Stolee 2020-08-05 17:08 ` Derrick Stolee 2020-04-06 16:59 ` [PATCH v4 06/15] commit-graph: compute Bloom filters for changed paths Garima Singh via GitGitGadget 2020-04-06 16:59 ` [PATCH v4 07/15] commit-graph: examine changed-path objects in pack order Jeff King via GitGitGadget 2020-04-06 16:59 ` [PATCH v4 08/15] commit-graph: examine commits by generation number Garima Singh via GitGitGadget 2020-04-06 16:59 ` [PATCH v4 09/15] commit-graph: write Bloom filters to commit graph file Garima Singh via GitGitGadget 2020-05-29 8:57 ` SZEDER Gábor 2020-05-29 13:35 ` Derrick Stolee 2020-05-31 17:23 ` SZEDER Gábor 2020-07-09 17:00 ` [PATCH] commit-graph: fix "Writing out commit graph" progress counter SZEDER Gábor 2020-07-09 18:01 ` Derrick Stolee 2020-07-09 18:20 ` Derrick Stolee 2020-04-06 16:59 ` [PATCH v4 10/15] commit-graph: reuse existing Bloom filters during write Garima Singh via GitGitGadget 2020-06-19 14:02 ` SZEDER Gábor 2020-06-19 19:28 ` Junio C Hamano 2020-07-27 21:33 ` SZEDER Gábor 2020-04-06 16:59 ` [PATCH v4 11/15] commit-graph: add --changed-paths option to write subcommand Garima Singh via GitGitGadget 2020-06-07 22:21 ` SZEDER Gábor 2020-04-06 16:59 ` [PATCH v4 12/15] revision.c: use Bloom filters to speed up path based revision walks Garima Singh via GitGitGadget 2020-06-26 6:34 ` SZEDER Gábor 2020-04-06 16:59 ` [PATCH v4 13/15] revision.c: add trace2 stats around Bloom filter usage Garima Singh via GitGitGadget 2020-04-06 16:59 ` [PATCH v4 14/15] t4216: add end to end tests for git log with Bloom filters Garima Singh via GitGitGadget 2020-04-06 16:59 ` [PATCH v4 15/15] commit-graph: add GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS test flag Garima Singh via GitGitGadget 2020-04-08 15:51 ` [PATCH v4 00/15] Changed Paths Bloom Filters Derrick Stolee 2020-04-08 19:21 ` Junio C Hamano 2020-04-08 20:05 ` Jakub Narębski 2020-04-12 20:34 ` Taylor Blau 2020-03-05 19:49 ` [PATCH 0/9] [RFC] " Garima Singh
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