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eredis_cluster

0.6.1
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An erlang wrapper for eredis library to support cluster mode

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eredis_cluster src eredis_cluster_hash.erl
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src/eredis_cluster_hash.erl 

%% @private

-module(eredis_cluster_hash).



%% API.

-export([hash/1]).



-include("eredis_cluster.hrl").



%% API.

-spec hash(string()) -> integer().

hash(Key) ->

    crc16(Key) rem ?REDIS_CLUSTER_HASH_SLOTS.



-spec crc16(string()) -> integer().

crc16(Key) ->

    crc16(Key, 0).



-spec crc16(string(), integer()) -> integer().

crc16([B|T], Crc) ->

    Index = (((Crc bsr 8) bxor B) band 16#ff),

    NewCrc = ((Crc bsl 8) band 16#ffff) bxor crc_index(Index),

    crc16(T, NewCrc);

crc16([], Crc) ->

    Crc.



-spec crc_index(integer()) -> integer().

crc_index(N) ->

    <<Crc:16>> = binary:part(?CRCDEF, N * 2, 2),

    Crc.