• antirez's avatar
    Changed HyperLogLog hash seed to a non-zero value. · 433ce7f8
    antirez authored
    Using a seed of zero has the side effect of having the empty string
    hashing to what is a very special case in the context of HyperLogLog: a
    very long run of zeroes.
    
    This did not influenced the correctness of the result with 16k registers
    because of the harmonic mean, but still it is inconvenient that a so
    obvious value maps to a so special hash.
    
    The seed 0xadc83b19 is used instead, which is the first 64 bits of the
    SHA1 of the empty string.
    
    Reference: issue #1657.
    433ce7f8
hyperloglog.c 27.4 KB