It seems that the result of hash algorithm used in bloom filter depends
on the pointer length. On 64bit platforms, there are 135 false positives
in the first part of that test, and 8 in the second part. However, on
32bit platforms, the numbers become 157 and 16 correspondingly.
16 is still less than 20% in the second part, so all fine, but 157 is
slightly larger than 15% in the test assertion. Given it is what we are
shipping, we probably should just accept this and loosen the assertion.
Bug: 1457524
Reviewed-by: heycam
MozReview-Commit-ID: 9kFXBzLFAzE
The current code is mostly bechmarking Rust's default hash routines for
integers, which is not interesting to us. We add generating function
that jumps around "enough" and also add benchmarks for clear().
It's hard to read too much into the numbers because we can't reliably
simulate L1/L2 cache behavior with cargo bench, but the results show
about 40ns for clear() about 2ns for insert, and about 1.5ns for
contains/remove. This informs our thinking in the next patch.
