[SPARK-23381][CORE] Murmur3 hash generates a different value from other implementations #20630
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hvanhovell
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Feb 16, 2018
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| public static int hashUnsafeBytes(Object base, long offset, int lengthInBytes, int seed) { | ||
| // This is not compatible with original and another implementations. | ||
| // But remain it for backward compatibility for the components existing before 2.3. |
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NIT: touch this up. The sentence is a bit weird, i.e.: However we retain this implementation for backwards compatibility with pre-existing (pre 2.3) components.
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Will correct it in the follow-up PR.
hvanhovell
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Feb 16, 2018
| Assert.assertEquals(-2106506049, hasher.hashLong(Long.MAX_VALUE)); | ||
| } | ||
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| // SPARK-23381 Check whether the hash of the byte array is the same as another implementations |
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We could add a randomized (disabled) test here. That might increase the confidence we have in the new hash.
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Yeah, we can do it in the follow-up PR.
hvanhovell
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Feb 16, 2018
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LGTM - pending jenkins
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The ML changes LGTM. Thanks! |
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LGTM |
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Test build #87514 has finished for PR 20630 at commit
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Thanks! Merged to master/2.3 |
asfgit
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Feb 17, 2018
…er implementations ## What changes were proposed in this pull request? Murmur3 hash generates a different value from the original and other implementations (like Scala standard library and Guava or so) when the length of a bytes array is not multiple of 4. ## How was this patch tested? Added a unit test. **Note: When we merge this PR, please give all the credits to Shintaro Murakami.** Author: Shintaro Murakami <mrkm4ntrgmail.com> Author: gatorsmile <[email protected]> Author: Shintaro Murakami <[email protected]> Closes #20630 from gatorsmile/pr-20568. (cherry picked from commit d5ed210) Signed-off-by: gatorsmile <[email protected]>
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What changes were proposed in this pull request?
Murmur3 hash generates a different value from the original and other implementations (like Scala standard library and Guava or so) when the length of a bytes array is not multiple of 4.
How was this patch tested?
Added a unit test.
Note: When we merge this PR, please give all the credits to Shintaro Murakami.
Author: Shintaro Murakami [email protected]