Re: Hash Table Collisions (n.runs-SA-2011.004)

[Roberto Ierusalimschy <roberto@...>]

> my gut feeling is that you're right for strings longer than 1k or so;
> but strings less than 80 doesn't seem unreasonable to compare and use
> as key.
> 
> does 32 has any nice advantage as a limit? or would 64 work as well?

Any value would do. It does not even have to be a power of 2. And there
would be no visible difference between both kinds of strings (except for
[hopefully small] performance differences).

The main balance is between computing the hash for all strings up to N
bytes, regardless of whether they will be used as a key (as it is
done today) versus doing string equality comparisons (including when
hashing) with memcmp instead of pointer equality.

-- Roberto