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| author |  Garima Singh <garima.singh@microsoft.com> | 2020-03-30 00:31:24 +0000 |
|---|---|---|
| committer |  Junio C Hamano <gitster@pobox.com> | 2020-03-30 09:59:53 -0700 |
| commit | f52207a45ca9e7cfbe431f4ffff79b3fdbcf3a37 (patch) | |
| tree | f0cec587c23bece10b7daf2fe2ea9a0a3e8596f0 /t | |
| parent | commit-graph: define and use MAX_NUM_CHUNKS (diff) | |
| download | tgif-f52207a45ca9e7cfbe431f4ffff79b3fdbcf3a37.tar.xz | |
bloom.c: add the murmur3 hash implementation
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>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 't')
| -rw-r--r-- | t/helper/test-bloom.c | 13 | ||||
| -rw-r--r-- | t/helper/test-tool.c | 1 | ||||
| -rw-r--r-- | t/helper/test-tool.h | 1 | ||||
| -rwxr-xr-x | t/t0095-bloom.sh | 30 |
4 files changed, 45 insertions, 0 deletions
diff --git a/t/helper/test-bloom.c b/t/helper/test-bloom.c new file mode 100644 index 0000000000..60ee204368 --- /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 31eedcd241..6e26bd65c9 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 4eb5e6609e..dceeef1d5c 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 0000000000..2dad8c4a94 --- /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 |