This function, based on murmurhash3, has much better distribution than
the original. Using the current default of 4096 buckets, there are many
fewer collisions:
Before:
2893000 entries and 4096/4096 buckets used, longest chain length 1649
After:
2732000 entries and 4096/4096 buckets used, longest chain length 764
The difference becomes much more significant when buckets are increased.
A naive attempt to expand the current function to larger outputs doesn't
yield any significant improvement; so this function is a prerequisite
for increasing the bucket size.
Signed-off-by: John Brooks <john.brooks@jolla.com>
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