mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-09-21 09:10:48 +00:00
279 lines
6.6 KiB
C++
279 lines
6.6 KiB
C++
#pragma once
|
||
|
||
#include <string.h>
|
||
#include <city.h>
|
||
|
||
#include <string>
|
||
#include <vector>
|
||
|
||
#include <functional>
|
||
#include <ostream>
|
||
|
||
#include <emmintrin.h>
|
||
|
||
|
||
/// Штука, чтобы не создавать строки для поиска подстроки в хэш таблице.
|
||
struct StringRef
|
||
{
|
||
const char * data = nullptr;
|
||
size_t size = 0;
|
||
|
||
StringRef(const char * data_, size_t size_) : data(data_), size(size_) {}
|
||
StringRef(const unsigned char * data_, size_t size_) : data(reinterpret_cast<const char *>(data_)), size(size_) {}
|
||
StringRef(const std::string & s) : data(s.data()), size(s.size()) {}
|
||
StringRef() {}
|
||
|
||
std::string toString() const { return std::string(data, size); }
|
||
};
|
||
|
||
typedef std::vector<StringRef> StringRefs;
|
||
|
||
|
||
/** Сравнение строк на равенство.
|
||
* Подход является спорным и выигрывает не во всех случаях.
|
||
* Подробнее смотрите hash_map_string_2.cpp
|
||
*/
|
||
|
||
inline bool compareSSE2(const char * p1, const char * p2)
|
||
{
|
||
return 0xFFFF == _mm_movemask_epi8(_mm_cmpeq_epi8(
|
||
_mm_loadu_si128(reinterpret_cast<const __m128i *>(p1)),
|
||
_mm_loadu_si128(reinterpret_cast<const __m128i *>(p2))));
|
||
}
|
||
|
||
inline bool memequalSSE2Wide(const char * p1, const char * p2, size_t size)
|
||
{
|
||
while (size >= 64)
|
||
{
|
||
if ( compareSSE2(p1, p2)
|
||
&& compareSSE2(p1 + 16, p2 + 16)
|
||
&& compareSSE2(p1 + 32, p2 + 32)
|
||
&& compareSSE2(p1 + 40, p2 + 40))
|
||
{
|
||
p1 += 64;
|
||
p2 += 64;
|
||
size -= 64;
|
||
}
|
||
else
|
||
return false;
|
||
}
|
||
|
||
switch ((size % 64) / 16)
|
||
{
|
||
case 3: if (!compareSSE2(p1 + 32, p2 + 32)) return false;
|
||
case 2: if (!compareSSE2(p1 + 16, p2 + 16)) return false;
|
||
case 1: if (!compareSSE2(p1 , p2 )) return false;
|
||
case 0: break;
|
||
}
|
||
|
||
p1 += (size % 64) / 16 * 16;
|
||
p2 += (size % 64) / 16 * 16;
|
||
|
||
switch (size % 16)
|
||
{
|
||
case 15: if (p1[14] != p2[14]) return false;
|
||
case 14: if (p1[13] != p2[13]) return false;
|
||
case 13: if (p1[12] != p2[12]) return false;
|
||
case 12: if (reinterpret_cast<const uint32_t *>(p1)[2] == reinterpret_cast<const uint32_t *>(p2)[2]) goto l8; else return false;
|
||
case 11: if (p1[10] != p2[10]) return false;
|
||
case 10: if (p1[9] != p2[9]) return false;
|
||
case 9: if (p1[8] != p2[8]) return false;
|
||
l8: case 8: return reinterpret_cast<const uint64_t *>(p1)[0] == reinterpret_cast<const uint64_t *>(p2)[0];
|
||
case 7: if (p1[6] != p2[6]) return false;
|
||
case 6: if (p1[5] != p2[5]) return false;
|
||
case 5: if (p1[4] != p2[4]) return false;
|
||
case 4: return reinterpret_cast<const uint32_t *>(p1)[0] == reinterpret_cast<const uint32_t *>(p2)[0];
|
||
case 3: if (p1[2] != p2[2]) return false;
|
||
case 2: return reinterpret_cast<const uint16_t *>(p1)[0] == reinterpret_cast<const uint16_t *>(p2)[0];
|
||
case 1: if (p1[0] != p2[0]) return false;
|
||
case 0: break;
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
|
||
inline bool operator== (StringRef lhs, StringRef rhs)
|
||
{
|
||
if (lhs.size != rhs.size)
|
||
return false;
|
||
|
||
if (lhs.size == 0)
|
||
return true;
|
||
|
||
return memequalSSE2Wide(lhs.data, rhs.data, lhs.size);
|
||
}
|
||
|
||
inline bool operator!= (StringRef lhs, StringRef rhs)
|
||
{
|
||
return !(lhs == rhs);
|
||
}
|
||
|
||
inline bool operator< (StringRef lhs, StringRef rhs)
|
||
{
|
||
int cmp = memcmp(lhs.data, rhs.data, std::min(lhs.size, rhs.size));
|
||
return cmp < 0 || (cmp == 0 && lhs.size < rhs.size);
|
||
}
|
||
|
||
inline bool operator> (StringRef lhs, StringRef rhs)
|
||
{
|
||
int cmp = memcmp(lhs.data, rhs.data, std::min(lhs.size, rhs.size));
|
||
return cmp > 0 || (cmp == 0 && lhs.size > rhs.size);
|
||
}
|
||
|
||
|
||
/** Хэш-функции.
|
||
* Можно использовать либо CityHash64,
|
||
* либо функцию на основе инструкции crc32,
|
||
* которая является заведомо менее качественной, но на реальных наборах данных,
|
||
* при использовании в хэш-таблице, работает существенно быстрее.
|
||
* Подробнее см. hash_map_string_3.cpp
|
||
*/
|
||
|
||
#ifdef __SSE4_1__
|
||
#include <smmintrin.h>
|
||
#else
|
||
|
||
inline uint64 _mm_crc32_u64(uint64 crc, uint64 value)
|
||
{
|
||
asm("crc32q %[value], %[crc]\n" : [crc] "+r" (crc) : [value] "rm" (value));
|
||
return crc;
|
||
}
|
||
|
||
#endif
|
||
|
||
/// Кусочки взяты из CityHash.
|
||
|
||
inline uint64 hashLen16(uint64 u, uint64 v)
|
||
{
|
||
return Hash128to64(uint128(u, v));
|
||
}
|
||
|
||
inline uint64 shiftMix(uint64 val)
|
||
{
|
||
return val ^ (val >> 47);
|
||
}
|
||
|
||
inline uint64 rotateByAtLeast1(uint64 val, int shift)
|
||
{
|
||
return (val >> shift) | (val << (64 - shift));
|
||
}
|
||
|
||
inline size_t hashLessThan8(const char * data, size_t size)
|
||
{
|
||
static constexpr uint64 k2 = 0x9ae16a3b2f90404fULL;
|
||
static constexpr uint64 k3 = 0xc949d7c7509e6557ULL;
|
||
|
||
if (size >= 4)
|
||
{
|
||
uint64 a = *reinterpret_cast<const uint32_t *>(data);;
|
||
return hashLen16(size + (a << 3), *reinterpret_cast<const uint32_t *>(data + size - 4));
|
||
}
|
||
|
||
if (size > 0)
|
||
{
|
||
uint8 a = data[0];
|
||
uint8 b = data[size >> 1];
|
||
uint8 c = data[size - 1];
|
||
uint32 y = static_cast<uint32>(a) + (static_cast<uint32>(b) << 8);
|
||
uint32 z = size + (static_cast<uint32>(c) << 2);
|
||
return shiftMix(y * k2 ^ z * k3) * k2;
|
||
}
|
||
|
||
return k2;
|
||
}
|
||
|
||
inline size_t hashLessThan16(const char * data, size_t size)
|
||
{
|
||
if (size > 8)
|
||
{
|
||
uint64 a = *reinterpret_cast<const uint64_t *>(data);
|
||
uint64 b = *reinterpret_cast<const uint64_t *>(data + size - 8);
|
||
return hashLen16(a, rotateByAtLeast1(b + size, size)) ^ b;
|
||
}
|
||
|
||
return hashLessThan8(data, size);
|
||
}
|
||
|
||
struct CRC32Hash
|
||
{
|
||
size_t operator() (StringRef x) const
|
||
{
|
||
const char * pos = x.data;
|
||
size_t size = x.size;
|
||
|
||
if (size == 0)
|
||
return 0;
|
||
|
||
if (size < 8)
|
||
{
|
||
return hashLessThan8(x.data, x.size);
|
||
}
|
||
|
||
const char * end = pos + size;
|
||
size_t res = -1ULL;
|
||
|
||
do
|
||
{
|
||
uint64_t word = *reinterpret_cast<const uint64_t *>(pos);
|
||
res = _mm_crc32_u64(res, word);
|
||
|
||
pos += 8;
|
||
} while (pos + 8 < end);
|
||
|
||
uint64_t word = *reinterpret_cast<const uint64_t *>(end - 8); /// Не уверен, что это нормально.
|
||
res = _mm_crc32_u64(res, word);
|
||
|
||
return res;
|
||
}
|
||
};
|
||
|
||
|
||
#if 1
|
||
|
||
struct StringRefHash : CRC32Hash {};
|
||
|
||
#else
|
||
|
||
struct StringRefHash
|
||
{
|
||
size_t operator() (StringRef x) const
|
||
{
|
||
return CityHash64(x.data, x.size);
|
||
}
|
||
};
|
||
|
||
#endif
|
||
|
||
|
||
namespace std
|
||
{
|
||
template <>
|
||
struct hash<StringRef> : public StringRefHash {};
|
||
}
|
||
|
||
|
||
namespace ZeroTraits
|
||
{
|
||
inline bool check(StringRef x) { return 0 == x.size; }
|
||
inline void set(StringRef & x) { x.size = 0; }
|
||
};
|
||
|
||
|
||
inline bool operator==(StringRef lhs, const char * rhs)
|
||
{
|
||
for (size_t pos = 0; pos < lhs.size; ++pos)
|
||
if (!rhs[pos] || lhs.data[pos] != rhs[pos])
|
||
return false;
|
||
|
||
return true;
|
||
}
|
||
|
||
inline std::ostream & operator<<(std::ostream & os, const StringRef & str)
|
||
{
|
||
if (str.data)
|
||
os.write(str.data, str.size);
|
||
|
||
return os;
|
||
}
|