ClickHouse

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#include "FunctionsConsistentHashing.h"
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#include <Functions/FunctionFactory.h>
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#include <consistent_hashing.h>
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namespace DB
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{
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/// An O(1) time and space consistent hash algorithm by Konstantin Oblakov
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struct KostikConsistentHashImpl
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{
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    static constexpr auto name = "kostikConsistentHash";
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    using HashType = UInt64;
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    /// Actually it supports UInt64, but it is efficient only if n <= 32768
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    using ResultType = UInt16;
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    using BucketsType = ResultType;
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    static constexpr auto max_buckets = 32768;
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    static inline ResultType apply(UInt64 hash, BucketsType n)
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    {
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        return ConsistentHashing(hash, n);
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    }
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};
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using FunctionKostikConsistentHash = FunctionConsistentHashImpl<KostikConsistentHashImpl>;
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REGISTER_FUNCTION(KostikConsistentHash)
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{
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    factory.registerFunction<FunctionKostikConsistentHash>();
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    factory.registerAlias("yandexConsistentHash", "kostikConsistentHash");
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}
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}
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