ClickHouse/src/Functions/kostikConsistentHash.cpp
Li Yin 4088c0a7f3 Automated function registration
Automated register all functions with below naming convention by
iterating through the symbols:
void DB::registerXXX(DB::FunctionFactory &)
2022-07-29 15:39:50 +08:00

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914 B
C++

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