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Added MurmurHash3.

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Бранимир Караџић
2023-10-21 11:07:25 -07:00
parent 97332257ff
commit ac1401faad
4 changed files with 339 additions and 92 deletions
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225
src/hash.cpp
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@@ -147,47 +147,6 @@ void HashCrc32::add(const void* _data, int32_t _len)
m_hash = hash;
}
struct HashMurmur2APod
{
uint32_t m_hash;
uint32_t m_tail;
uint32_t m_count;
uint32_t m_size;
};
BX_STATIC_ASSERT(sizeof(HashMurmur2A) == sizeof(HashMurmur2APod) );
BX_FORCE_INLINE void mmix(uint32_t& _h, uint32_t& _k)
{
constexpr uint32_t kMurmurMul = 0x5bd1e995;
constexpr uint32_t kMurmurRightShift = 24;
_k *= kMurmurMul;
_k ^= _k >> kMurmurRightShift;
_k *= kMurmurMul;
_h *= kMurmurMul;
_h ^= _k;
}
static void mixTail(HashMurmur2APod& _self, const uint8_t*& _data, int32_t& _len)
{
while (_len
&& ( (_len<4) || _self.m_count)
)
{
_self.m_tail |= (*_data++) << (_self.m_count * 8);
_self.m_count++;
_len--;
if (_self.m_count == 4)
{
mmix(_self.m_hash, _self.m_tail);
_self.m_tail = 0;
_self.m_count = 0;
}
}
}
BX_FORCE_INLINE uint32_t readAligned(const uint8_t* _data)
{
return *(uint32_t*)_data;
@@ -195,36 +154,45 @@ BX_FORCE_INLINE uint32_t readAligned(const uint8_t* _data)
BX_FORCE_INLINE uint32_t readUnaligned(const uint8_t* _data)
{
if (BX_ENABLED(BX_CPU_ENDIAN_BIG) )
return 0
| _data[3]<<24
| _data[2]<<16
| _data[1]<<8
| _data[0]
;
}
namespace
{
template<typename Ty>
void mixTail(Ty& _self, const uint8_t*& _data, int32_t& _len)
{
while (0 != _len
&& (0 < _self.m_count || 4 > _len) )
{
return 0
| _data[0]<<24
| _data[1]<<16
| _data[2]<<8
| _data[3]
;
}
else
{
return 0
| _data[0]
| _data[1]<<8
| _data[2]<<16
| _data[3]<<24
;
_self.m_tail[_self.m_count++] = *_data++;
_len--;
if (4 == _self.m_count)
{
uint32_t kk = *( (uint32_t*)&_self.m_tail[0]);
_self.mix(kk);
_self.m_count = 0;
}
}
}
typedef uint32_t (*ReadDataFn)(const uint8_t* _data);
template<ReadDataFn FnT>
static void addData(HashMurmur2APod& _self, const uint8_t* _data, int32_t _len)
template<typename Ty, ReadDataFn FnT>
void addData(Ty& _self, const uint8_t* _data, int32_t _len)
{
while (_len >= 4)
{
uint32_t kk = FnT(_data);
mmix(_self.m_hash, kk);
_self.mix(kk);
_data += 4;
_len -= 4;
@@ -233,36 +201,149 @@ static void addData(HashMurmur2APod& _self, const uint8_t* _data, int32_t _len)
mixTail(_self, _data, _len);
}
void HashMurmur2A::add(const void* _data, int32_t _len)
template<typename SelfT, typename ThisT>
void addData(ThisT* _this, const void* _data, int32_t _len)
{
HashMurmur2APod& self = *(HashMurmur2APod*)this;
SelfT& self = *(SelfT*)_this;
const uint8_t* data = (const uint8_t*)_data;
m_size += _len;
self.m_size += _len;
mixTail(self, data, _len);
if (BX_UNLIKELY(!isAligned(data, 4) ) )
{
addData<readUnaligned>(self, data, _len);
addData<SelfT, readUnaligned>(self, data, _len);
return;
}
addData<readAligned>(self, data, _len);
addData<SelfT, readAligned>(self, data, _len);
}
template<typename SelfT, typename ThisT>
uint32_t finalize(ThisT* _this)
{
SelfT& self = *(SelfT*)_this;
self.finalize();
return self.m_hash;
}
} // namespace
struct HashMurmur2APod
{
uint32_t m_hash;
uint32_t m_size;
uint8_t m_tail[4];
uint8_t m_count;
static constexpr uint32_t kMurmur2AMul = 0x5bd1e995;
BX_FORCE_INLINE void mix(uint32_t& _k)
{
_k *= kMurmur2AMul;
_k ^= _k >> 24;
_k *= kMurmur2AMul;
m_hash *= kMurmur2AMul;
m_hash ^= _k;
}
void finalize()
{
uint32_t kk = 0;
switch (m_count)
{
case 3: kk |= m_tail[2] << 16; BX_FALLTHROUGH;
case 2: kk |= m_tail[1] << 8; BX_FALLTHROUGH;
case 1: kk |= m_tail[0]; BX_FALLTHROUGH;
case 0: mix(kk); break;
default: BX_ASSERT(false, "Bug, m_count can't be %d (expected < 4).", m_count); BX_UNREACHABLE;
}
mix(m_size);
m_hash ^= m_hash >> 13;
m_hash *= kMurmur2AMul;
m_hash ^= m_hash >> 15;
}
};
BX_STATIC_ASSERT(sizeof(HashMurmur2A) == sizeof(HashMurmur2APod) );
void HashMurmur2A::add(const void* _data, int32_t _len)
{
addData<HashMurmur2APod>(this, _data, _len);
}
uint32_t HashMurmur2A::end()
{
constexpr uint32_t kMurmurMul = 0x5bd1e995;
return finalize<HashMurmur2APod>(this);
}
mmix(m_hash, m_tail);
mmix(m_hash, m_size);
struct HashMurmur3Pod
{
uint32_t m_hash;
uint32_t m_size;
uint8_t m_tail[4];
uint8_t m_count;
m_hash ^= m_hash >> 13;
m_hash *= kMurmurMul;
m_hash ^= m_hash >> 15;
static constexpr uint32_t kMurmur3Mul1 = 0xcc9e2d51;
static constexpr uint32_t kMurmur3Mul2 = 0x1b873593;
static constexpr uint32_t kMurmur3Mul3 = 0x85ebca6b;
static constexpr uint32_t kMurmur3Mul4 = 0xc2b2ae35;
static constexpr uint32_t kMurmur3Add = 0xe6546b64;
return m_hash;
BX_FORCE_INLINE void mix1(uint32_t _k)
{
_k *= kMurmur3Mul1;
_k = uint32_rol(_k, 15);
_k *= kMurmur3Mul2;
m_hash ^= _k;
}
BX_FORCE_INLINE void mix(uint32_t _k)
{
mix1(_k);
m_hash = uint32_rol(m_hash, 13);
m_hash = m_hash*5 + kMurmur3Add;
}
void finalize()
{
uint32_t kk = 0;
switch (m_count)
{
case 3: kk |= m_tail[2] << 16; BX_FALLTHROUGH;
case 2: kk |= m_tail[1] << 8; BX_FALLTHROUGH;
case 1: kk |= m_tail[0]; mix1(kk); break;
case 0: break;
default: BX_ASSERT(false, "Bug, m_count can't be %d (expected < 4).", m_count); BX_UNREACHABLE;
}
m_hash ^= m_size;
m_hash ^= m_hash >> 16;
m_hash *= kMurmur3Mul3;
m_hash ^= m_hash >> 13;
m_hash *= kMurmur3Mul4;
m_hash ^= m_hash >> 16;
}
};
BX_STATIC_ASSERT(sizeof(HashMurmur3) == sizeof(HashMurmur3Pod) );
void HashMurmur3::add(const void* _data, int32_t _len)
{
addData<HashMurmur3Pod>(this, _data, _len);
}
uint32_t HashMurmur3::end()
{
return finalize<HashMurmur3Pod>(this);
}
} // namespace bx