1. 14 Apr, 2014 10 commits
  2. 13 Apr, 2014 3 commits
  3. 12 Apr, 2014 10 commits
  4. 11 Apr, 2014 4 commits
  5. 10 Apr, 2014 1 commit
    • antirez's avatar
      HyperLogLog sparse representation slightly modified. · 9c037ba8
      antirez authored
      After running a few simulations with different alternative encodings,
      it was found that the VAL opcode performs better using 5 bits for the
      value and 2 bits for the run length, at least for cardinalities in the
      range of interest.
      9c037ba8
  6. 09 Apr, 2014 1 commit
  7. 04 Apr, 2014 2 commits
    • antirez's avatar
      PFCOUNT: always unshare/decode the object. · d5be696d
      antirez authored
      This will be a non-op most of the times since the object will be
      unshared / decoded, however it is more technically correct to start this
      way since the object may be decoded even in the read-only code path.
      d5be696d
    • 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
  8. 03 Apr, 2014 6 commits
  9. 02 Apr, 2014 1 commit
    • antirez's avatar
      HyperLogLog: added magic / version. · 096b5e92
      antirez authored
      This will allow future changes like compressed representations.
      Currently the magic is not checked for performance reasons but this may
      change in the future, for example if we add new types encoded in strings
      that may have the same size of HyperLogLogs.
      096b5e92
  10. 01 Apr, 2014 2 commits