Bankim Bhavsar has posted comments on this change. ( http://gerrit.cloudera.org:8080/14934 )
Change subject: [util] Import FastHash hash function to util ...................................................................... Patch Set 5: (7 comments) http://gerrit.cloudera.org:8080/#/c/14934/3/src/kudu/util/hash_util-test.cc File src/kudu/util/hash_util-test.cc: http://gerrit.cloudera.org:8080/#/c/14934/3/src/kudu/util/hash_util-test.cc@42 PS3, Line 42: // Test FastHash64/32 returns the expected values for inputs. These tests are > Does it make sense to add a small test to make sure this hash implementatio As per smhasher https://github.com/rurban/smhasher, fasthash is similar in speed as compared to Murmur2Hash(64-bit variant we use) for 64-bit but with fewer quality problems. fasthash32 4658.24 50.50 181.96 (2) 566 fasthash64 4657.64 47.71 168.22 (3) 509 MomentChi2 5159 ! Murmur2B 4728.94 47.90 192.82 (18) 433 1.8% bias, collisions, 3.4% distrib, BIC I see fasthash comes with it's own benchmarking tests, so I can try importing those tests and comparing. http://gerrit.cloudera.org:8080/#/c/14934/3/src/kudu/util/hash_util.h File src/kudu/util/hash_util.h: http://gerrit.cloudera.org:8080/#/c/14934/3/src/kudu/util/hash_util.h@34 PS3, Line 34: static constexpr uint64_t MURMUR_PRIME = 0xc6a4a7935bd1e995UL; > nit: add UL suffix just for the unification with the way those constants ar Done http://gerrit.cloudera.org:8080/#/c/14934/3/src/kudu/util/hash_util.h@73 PS3, Line 73: ATTRIBUTE_NO_SANITIZE_INTEGER > +1 Is +1 to Adar's comment or my comment? If to Adar's comment, explanation is same as above. If you guys feel strongly about dropping the inline keyword then I can do it. http://gerrit.cloudera.org:8080/#/c/14934/3/src/kudu/util/hash_util.h@74 PS3, Line 74: line > Would constexp do any difference here? Done http://gerrit.cloudera.org:8080/#/c/14934/3/src/kudu/util/hash_util.h@74 PS3, Line 74: a > style nit: it should be some thing like M or kM, kMultiplier of whatever ac Done http://gerrit.cloudera.org:8080/#/c/14934/3/src/kudu/util/hash_util.h@75 PS3, Line 75: f > nit: drop the extra space? Done http://gerrit.cloudera.org:8080/#/c/14934/3/src/kudu/util/hash_util.h@86 PS3, Line 86: > nit: drop the extra space? Done -- To view, visit http://gerrit.cloudera.org:8080/14934 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Id0a21d6af10d9ba0dbd9ab46d73552d42976e8d7 Gerrit-Change-Number: 14934 Gerrit-PatchSet: 5 Gerrit-Owner: Bankim Bhavsar <ban...@cloudera.com> Gerrit-Reviewer: Adar Dembo <a...@cloudera.com> Gerrit-Reviewer: Alexey Serbin <aser...@cloudera.com> Gerrit-Reviewer: Bankim Bhavsar <ban...@cloudera.com> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Reviewer: Tidy Bot (241) Gerrit-Reviewer: Todd Lipcon <t...@apache.org> Gerrit-Comment-Date: Thu, 26 Dec 2019 20:45:06 +0000 Gerrit-HasComments: Yes
