umgeher/leveled
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Use more keys in bloom

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Use 4 keys in the bloom (which is closer to optimal size).  This should halve the fpr - as we cna now use the large ExtraHash rather than being constrained by the SegmentHash here.
This commit is contained in:
Martin Sumner 2017-10-24 15:42:53 +01:00
parent f08faf6432
commit 6af1d3b003
2 changed files with 31 additions and 86 deletions
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2
src/leveled_codec.erl
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@ -88,7 +88,7 @@
%% speed can be gained if just the segment ID is known - but more can be
%% gained should the extended hash (with the second element) is known
segment_hash(Key) when is_binary(Key) ->
<<SegmentID:16/integer, ExtraHash:16/integer, _Rest/binary>> =
<<SegmentID:16/integer, ExtraHash:32/integer, _Rest/binary>> =
crypto:hash(md5, Key),
{SegmentID, ExtraHash};
segment_hash(Key) ->