On Mon, Feb 18, 2013 at 4:41 PM, Tomasz Kuzemko <tom...@kuzemko.net> wrote:
> Did not look at the code, but seems like it is part of some general hash > table implementation. > > It is for a hash table AFAICT. > Good explanation why these are primes: > > http://stackoverflow.com/**questions/1145217/why-should-** > hash-functions-use-a-prime-**number-modulus<http://stackoverflow.com/questions/1145217/why-should-hash-functions-use-a-prime-number-modulus> > > Ah, that is very interesting and makes good sense. I will add a comment. Thanks. > Best regards, > Tomasz Kuzemko > tom...@kuzemko.net > > W dniu 18.02.2013 20:50, Phil Sorber pisze: > > In looking through RamCacheCLFUS I came upon this: >> >> static const int bucket_sizes[] = { >> 127, 251, 509, 1021, 2039, 4093, 8191, 16381, 32749, 65521, 131071, >> 262139, >> 524287, 1048573, 2097143, 4194301, 8388593, 16777213, 33554393, >> 67108859, >> 134217689, 268435399, 536870909, 1073741789, 2147483647 >> }; >> >> Looking through git blame and JIRA it looks like it was part of the >> initial >> patch for CLFUS. In talking with James in IRC he pointed out that it looks >> like the largest prime less than a power of 2. This seems like a very >> deliberate choice, but I can't figure out why and there are no docs >> explaining. Can someone, perhaps John, shed some light on it? >> >> Thanks. >> >>
