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#pragma once
#include <util/system/defaults.h>
#include <util/generic/array_ref.h>
/*
* murmur2 from http://murmurhash.googlepages.com/
*
*/
namespace NMurmurPrivate {
Y_PURE_FUNCTION ui32 MurmurHash32(const void* key, size_t len, ui32 seed) noexcept;
Y_PURE_FUNCTION ui64 MurmurHash64(const void* key, size_t len, ui64 seed) noexcept;
template <unsigned N>
struct TMurHelper;
#define DEF_MUR(t) \
template <> \
struct TMurHelper<t> { \
static inline ui##t MurmurHash(const void* buf, size_t len, ui##t init) noexcept { \
return MurmurHash##t(buf, len, init); \
} \
};
DEF_MUR(32)
DEF_MUR(64)
#undef DEF_MUR
} // namespace NMurmurPrivate
template <class T>
inline T MurmurHash(const void* buf, size_t len, T init) noexcept {
return (T)NMurmurPrivate::TMurHelper<8 * sizeof(T)>::MurmurHash(buf, len, init);
}
template <class T>
inline T MurmurHash(const void* buf, size_t len) noexcept {
return MurmurHash<T>(buf, len, (T)0);
}
template <typename TOut = size_t>
struct TMurmurHash {
TOut operator()(const void* buf, size_t len) const noexcept {
return MurmurHash<TOut>(buf, len);
}
template <typename ElementType>
TOut operator()(const TArrayRef<ElementType>& data) const noexcept {
return operator()(data.data(), data.size() * sizeof(ElementType));
}
};
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