Safety #8
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Safety #8
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Owner
twmb
commented
Apr 1, 2020
twmb
commented
- fixes non-amd64 code (missing import)
- changes some testing to not run against the canonical source on big arches
- follow Go's safety rules to the T (0.4ns perf hit)
- add endianness and safety to readme and update benchmarks
How this was missing is beyond me.
The canonical source does the unsafe bytes to int trick. This code always reads as little endian. On big arches, the canonical source will return different results than our little endian reading, so we avoid testing against the canonical source on big arches.
Go issue 19367 (golang/go#19367) and a linked issue at the bottom indicate that the following trick *(*string)(unsafe.Pointer(&slice)) is not theoretically safe. While I doubt that the Go people will ever actually break that code since it would break a loooot of other code, we may as well convert back to safe code. The prior commit removed reflect because we were converting from a string to a slice; this re-introduces it because converting from a slice to a string adds only 0.4ns of overhead but adds following the rules of Go to the letter. After this commit, this library effectively follows all rules of unsafety (and is likely one of the few murmur3 libraries that does so).
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