Modified source engine (2017) developed by valve and leaked in 2020. Not for commercial purporses
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2.1 KiB

5 years ago
//======= Copyright <EFBFBD> Valve Corporation, All rights reserved. =================
//
// Public domain MurmurHash3 by Austin Appleby is a very solid general-purpose
// hash with a 32-bit output. References:
// http://code.google.com/p/smhasher/ (home of MurmurHash3)
// https://sites.google.com/site/murmurhash/avalanche
// http://www.strchr.com/hash_functions
//
//=============================================================================
#ifndef MURMURHASH3_H
#define MURMURHASH3_H
#if defined(_WIN32)
#pragma once
#endif
uint32 MurmurHash3_32( const void *key, size_t len, uint32 seed, bool bCaselessStringVariant = false );
inline uint32 MurmurHash3String( const char *pszKey, size_t len )
{
return MurmurHash3_32( pszKey, len, 1047 /*anything will do for a seed*/, false );
}
inline uint32 MurmurHash3StringCaseless( const char *pszKey, size_t len )
{
return MurmurHash3_32( pszKey, len, 1047 /*anything will do for a seed*/, true );
}
inline uint32 MurmurHash3String( const char *pszKey )
{
return MurmurHash3String( pszKey, strlen( pszKey ) );
}
inline uint32 MurmurHash3StringCaseless( const char *pszKey )
{
return MurmurHash3StringCaseless( pszKey, strlen( pszKey ) );
}
template <typename T>
inline uint32 MurmurHash3Item( const T &item )
{
return MurmurHash3_32( &item, sizeof(item), 1047 );
}
inline uint32 MurmurHash3Int( uint32 h )
{
h ^= h >> 16;
h *= 0x85ebca6b;
h ^= h >> 13;
h *= 0xc2b2ae35;
h ^= h >> 16;
return h;
}
template <>
inline uint32 MurmurHash3Item( const uint32 &item )
{
return MurmurHash3Int( item );
}
template <>
inline uint32 MurmurHash3Item( const int32 &item )
{
return MurmurHash3Int( item );
}
template<typename T>
struct MurmurHash3Functor
{
typedef uint32 TargetType;
TargetType operator()(const T &key) const
{
return MurmurHash3Item( key );
}
};
template<>
struct MurmurHash3Functor<char *>
{
typedef uint32 TargetType;
TargetType operator()(const char *key) const
{
return MurmurHash3String( key );
}
};
template<>
struct MurmurHash3Functor<const char *>
{
typedef uint32 TargetType;
TargetType operator()(const char *key) const
{
return MurmurHash3String( key );
}
};
#endif // MURMURHASH3_H