332 lines
11 KiB
C
332 lines
11 KiB
C
|
/**
|
||
|
|
*
|
||
|
|
* @file string_view.h
|
||
|
|
* @author An Tao
|
||
|
|
*
|
||
|
|
* Copyright 2018, An Tao. All rights reserved.
|
||
|
|
* https://github.com/an-tao/drogon
|
||
|
|
* Use of this source code is governed by a MIT license
|
||
|
|
* that can be found in the License file.
|
||
|
|
*
|
||
|
|
* Drogon
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
#pragma once
|
||
|
|
#if __cplusplus >= 201703L || (defined _MSC_VER && _MSC_VER > 1900)
|
||
|
|
#include <string_view>
|
||
|
|
#else
|
||
|
|
#include <stdint.h>
|
||
|
|
#include <boost/utility/string_view.hpp>
|
||
|
|
#include <boost/functional/hash.hpp>
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#include <trantor/utils/LogStream.h>
|
||
|
|
|
||
|
|
namespace drogon
|
||
|
|
{
|
||
|
|
#if __cplusplus >= 201703L || (defined _MSC_VER && _MSC_VER > 1900)
|
||
|
|
using std::string_view;
|
||
|
|
#else
|
||
|
|
using boost::string_view;
|
||
|
|
#endif
|
||
|
|
} // namespace drogon
|
||
|
|
namespace trantor
|
||
|
|
{
|
||
|
|
inline LogStream &operator<<(LogStream &ls, const drogon::string_view &v)
|
||
|
|
{
|
||
|
|
ls.append(v.data(), v.length());
|
||
|
|
return ls;
|
||
|
|
}
|
||
|
|
} // namespace trantor
|
||
|
|
|
||
|
|
#if __cplusplus < 201703L && !(defined _MSC_VER && _MSC_VER > 1900)
|
||
|
|
namespace drogon
|
||
|
|
{
|
||
|
|
#ifndef _MSC_VER
|
||
|
|
template <size_t N>
|
||
|
|
struct StringViewHasher;
|
||
|
|
|
||
|
|
template <>
|
||
|
|
struct StringViewHasher<4>
|
||
|
|
{
|
||
|
|
size_t operator()(const drogon::string_view &__str) const noexcept
|
||
|
|
{
|
||
|
|
// Take from the memory header file
|
||
|
|
//===-------------------------- memory
|
||
|
|
//------------------------------------===//
|
||
|
|
//
|
||
|
|
// The LLVM Compiler Infrastructure
|
||
|
|
//
|
||
|
|
// This file is dual licensed under the MIT and the University of
|
||
|
|
// Illinois Open Source Licenses. See LICENSE.TXT for details.
|
||
|
|
//
|
||
|
|
//===----------------------------------------------------------------------===//
|
||
|
|
const uint32_t __m = 0x5bd1e995;
|
||
|
|
const uint32_t __r = 24;
|
||
|
|
uint32_t __h = __str.length();
|
||
|
|
auto __len = __h;
|
||
|
|
const unsigned char *__data = (const unsigned char *)(__str.data());
|
||
|
|
for (; __len >= 4; __data += 4, __len -= 4)
|
||
|
|
{
|
||
|
|
uint32_t __k = *((uint32_t *)__data);
|
||
|
|
__k *= __m;
|
||
|
|
__k ^= __k >> __r;
|
||
|
|
__k *= __m;
|
||
|
|
__h *= __m;
|
||
|
|
__h ^= __k;
|
||
|
|
}
|
||
|
|
switch (__len)
|
||
|
|
{
|
||
|
|
case 3:
|
||
|
|
__h ^= __data[2] << 16;
|
||
|
|
case 2:
|
||
|
|
__h ^= __data[1] << 8;
|
||
|
|
case 1:
|
||
|
|
__h ^= __data[0];
|
||
|
|
__h *= __m;
|
||
|
|
}
|
||
|
|
__h ^= __h >> 13;
|
||
|
|
__h *= __m;
|
||
|
|
__h ^= __h >> 15;
|
||
|
|
return __h;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
template <>
|
||
|
|
struct StringViewHasher<8>
|
||
|
|
{
|
||
|
|
static const size_t __k0 = 0xc3a5c85c97cb3127ULL;
|
||
|
|
static const size_t __k1 = 0xb492b66fbe98f273ULL;
|
||
|
|
static const size_t __k2 = 0x9ae16a3b2f90404fULL;
|
||
|
|
static const size_t __k3 = 0xc949d7c7509e6557ULL;
|
||
|
|
|
||
|
|
static size_t __rotate(size_t __val, int __shift)
|
||
|
|
{
|
||
|
|
return __shift == 0 ? __val
|
||
|
|
: ((__val >> __shift) | (__val << (64 - __shift)));
|
||
|
|
}
|
||
|
|
|
||
|
|
static size_t __rotate_by_at_least_1(size_t __val, int __shift)
|
||
|
|
{
|
||
|
|
return (__val >> __shift) | (__val << (64 - __shift));
|
||
|
|
}
|
||
|
|
|
||
|
|
static size_t __shift_mix(size_t __val)
|
||
|
|
{
|
||
|
|
return __val ^ (__val >> 47);
|
||
|
|
}
|
||
|
|
|
||
|
|
static size_t __hash_len_16(size_t __u, size_t __v)
|
||
|
|
{
|
||
|
|
const size_t __mul = 0x9ddfea08eb382d69ULL;
|
||
|
|
size_t __a = (__u ^ __v) * __mul;
|
||
|
|
__a ^= (__a >> 47);
|
||
|
|
size_t __b = (__v ^ __a) * __mul;
|
||
|
|
__b ^= (__b >> 47);
|
||
|
|
__b *= __mul;
|
||
|
|
return __b;
|
||
|
|
}
|
||
|
|
template <class Size>
|
||
|
|
inline static Size __loadword(const void *__p)
|
||
|
|
{
|
||
|
|
Size __r;
|
||
|
|
std::memcpy(&__r, __p, sizeof(__r));
|
||
|
|
return __r;
|
||
|
|
}
|
||
|
|
|
||
|
|
static size_t __hash_len_0_to_16(const char *__s, size_t __len)
|
||
|
|
{
|
||
|
|
if (__len > 8)
|
||
|
|
{
|
||
|
|
const size_t __a = __loadword<size_t>(__s);
|
||
|
|
const size_t __b = __loadword<size_t>(__s + __len - 8);
|
||
|
|
return __hash_len_16(__a,
|
||
|
|
__rotate_by_at_least_1(__b + __len, __len)) ^
|
||
|
|
__b;
|
||
|
|
}
|
||
|
|
if (__len >= 4)
|
||
|
|
{
|
||
|
|
const uint32_t __a = __loadword<uint32_t>(__s);
|
||
|
|
const uint32_t __b = __loadword<uint32_t>(__s + __len - 4);
|
||
|
|
return __hash_len_16(__len + (__a << 3), __b);
|
||
|
|
}
|
||
|
|
if (__len > 0)
|
||
|
|
{
|
||
|
|
const unsigned char __a = __s[0];
|
||
|
|
const unsigned char __b = __s[__len >> 1];
|
||
|
|
const unsigned char __c = __s[__len - 1];
|
||
|
|
const uint32_t __y =
|
||
|
|
static_cast<uint32_t>(__a) + (static_cast<uint32_t>(__b) << 8);
|
||
|
|
const uint32_t __z = __len + (static_cast<uint32_t>(__c) << 2);
|
||
|
|
return __shift_mix(__y * __k2 ^ __z * __k3) * __k2;
|
||
|
|
}
|
||
|
|
return __k2;
|
||
|
|
}
|
||
|
|
|
||
|
|
static size_t __hash_len_17_to_32(const char *__s, size_t __len)
|
||
|
|
{
|
||
|
|
const size_t __a = __loadword<size_t>(__s) * __k1;
|
||
|
|
const size_t __b = __loadword<size_t>(__s + 8);
|
||
|
|
const size_t __c = __loadword<size_t>(__s + __len - 8) * __k2;
|
||
|
|
const size_t __d = __loadword<size_t>(__s + __len - 16) * __k0;
|
||
|
|
return __hash_len_16(__rotate(__a - __b, 43) + __rotate(__c, 30) + __d,
|
||
|
|
__a + __rotate(__b ^ __k3, 20) - __c + __len);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Return a 16-byte hash for 48 bytes. Quick and dirty.
|
||
|
|
// Callers do best to use "random-looking" values for a and b.
|
||
|
|
static std::pair<size_t, size_t> __weak_hash_len_32_with_seeds(size_t __w,
|
||
|
|
size_t __x,
|
||
|
|
size_t __y,
|
||
|
|
size_t __z,
|
||
|
|
size_t __a,
|
||
|
|
size_t __b)
|
||
|
|
{
|
||
|
|
__a += __w;
|
||
|
|
__b = __rotate(__b + __a + __z, 21);
|
||
|
|
const size_t __c = __a;
|
||
|
|
__a += __x;
|
||
|
|
__a += __y;
|
||
|
|
__b += __rotate(__a, 44);
|
||
|
|
return std::pair<size_t, size_t>(__a + __z, __b + __c);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Return a 16-byte hash for s[0] ... s[31], a, and b. Quick and dirty.
|
||
|
|
static std::pair<size_t, size_t> __weak_hash_len_32_with_seeds(
|
||
|
|
const char *__s,
|
||
|
|
size_t __a,
|
||
|
|
size_t __b)
|
||
|
|
{
|
||
|
|
return __weak_hash_len_32_with_seeds(__loadword<size_t>(__s),
|
||
|
|
__loadword<size_t>(__s + 8),
|
||
|
|
__loadword<size_t>(__s + 16),
|
||
|
|
__loadword<size_t>(__s + 24),
|
||
|
|
__a,
|
||
|
|
__b);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Return an 8-byte hash for 33 to 64 bytes.
|
||
|
|
static size_t __hash_len_33_to_64(const char *__s, size_t __len)
|
||
|
|
{
|
||
|
|
size_t __z = __loadword<size_t>(__s + 24);
|
||
|
|
size_t __a = __loadword<size_t>(__s) +
|
||
|
|
(__len + __loadword<size_t>(__s + __len - 16)) * __k0;
|
||
|
|
size_t __b = __rotate(__a + __z, 52);
|
||
|
|
size_t __c = __rotate(__a, 37);
|
||
|
|
__a += __loadword<size_t>(__s + 8);
|
||
|
|
__c += __rotate(__a, 7);
|
||
|
|
__a += __loadword<size_t>(__s + 16);
|
||
|
|
size_t __vf = __a + __z;
|
||
|
|
size_t __vs = __b + __rotate(__a, 31) + __c;
|
||
|
|
__a =
|
||
|
|
__loadword<size_t>(__s + 16) + __loadword<size_t>(__s + __len - 32);
|
||
|
|
__z += __loadword<size_t>(__s + __len - 8);
|
||
|
|
__b = __rotate(__a + __z, 52);
|
||
|
|
__c = __rotate(__a, 37);
|
||
|
|
__a += __loadword<size_t>(__s + __len - 24);
|
||
|
|
__c += __rotate(__a, 7);
|
||
|
|
__a += __loadword<size_t>(__s + __len - 16);
|
||
|
|
size_t __wf = __a + __z;
|
||
|
|
size_t __ws = __b + __rotate(__a, 31) + __c;
|
||
|
|
size_t __r = __shift_mix((__vf + __ws) * __k2 + (__wf + __vs) * __k0);
|
||
|
|
return __shift_mix(__r * __k0 + __vs) * __k2;
|
||
|
|
}
|
||
|
|
size_t operator()(const drogon::string_view &__str) const noexcept
|
||
|
|
{
|
||
|
|
size_t __len = __str.length();
|
||
|
|
const char *__s = static_cast<const char *>(__str.data());
|
||
|
|
if (__len <= 32)
|
||
|
|
{
|
||
|
|
if (__len <= 16)
|
||
|
|
{
|
||
|
|
return __hash_len_0_to_16(__s, __len);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
return __hash_len_17_to_32(__s, __len);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else if (__len <= 64)
|
||
|
|
{
|
||
|
|
return __hash_len_33_to_64(__s, __len);
|
||
|
|
}
|
||
|
|
|
||
|
|
// For strings over 64 bytes we hash the end first, and then as we
|
||
|
|
// loop we keep 56 bytes of state: v, w, x, y, and z.
|
||
|
|
size_t __x = __loadword<size_t>(__s + __len - 40);
|
||
|
|
size_t __y = __loadword<size_t>(__s + __len - 16) +
|
||
|
|
__loadword<size_t>(__s + __len - 56);
|
||
|
|
size_t __z = __hash_len_16(__loadword<size_t>(__s + __len - 48) + __len,
|
||
|
|
__loadword<size_t>(__s + __len - 24));
|
||
|
|
std::pair<size_t, size_t> __v =
|
||
|
|
__weak_hash_len_32_with_seeds(__s + __len - 64, __len, __z);
|
||
|
|
std::pair<size_t, size_t> __w =
|
||
|
|
__weak_hash_len_32_with_seeds(__s + __len - 32, __y + __k1, __x);
|
||
|
|
__x = __x * __k1 + __loadword<size_t>(__s);
|
||
|
|
|
||
|
|
// Decrease len to the nearest multiple of 64, and operate on 64-byte
|
||
|
|
// chunks.
|
||
|
|
__len = (__len - 1) & ~static_cast<size_t>(63);
|
||
|
|
do
|
||
|
|
{
|
||
|
|
__x = __rotate(__x + __y + __v.first + __loadword<size_t>(__s + 8),
|
||
|
|
37) *
|
||
|
|
__k1;
|
||
|
|
__y =
|
||
|
|
__rotate(__y + __v.second + __loadword<size_t>(__s + 48), 42) *
|
||
|
|
__k1;
|
||
|
|
__x ^= __w.second;
|
||
|
|
__y += __v.first + __loadword<size_t>(__s + 40);
|
||
|
|
__z = __rotate(__z + __w.first, 33) * __k1;
|
||
|
|
__v = __weak_hash_len_32_with_seeds(__s,
|
||
|
|
__v.second * __k1,
|
||
|
|
__x + __w.first);
|
||
|
|
__w = __weak_hash_len_32_with_seeds(
|
||
|
|
__s + 32, __z + __w.second, __y + __loadword<size_t>(__s + 16));
|
||
|
|
std::swap(__z, __x);
|
||
|
|
__s += 64;
|
||
|
|
__len -= 64;
|
||
|
|
} while (__len != 0);
|
||
|
|
return __hash_len_16(__hash_len_16(__v.first, __w.first) +
|
||
|
|
__shift_mix(__y) * __k1 + __z,
|
||
|
|
__hash_len_16(__v.second, __w.second) + __x);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
#else
|
||
|
|
|
||
|
|
// Taken and modified from https://stackoverflow.com/a/8317622/3687637
|
||
|
|
struct ShortStringViewHasher
|
||
|
|
{
|
||
|
|
size_t operator()(const string_view &sv) const
|
||
|
|
{
|
||
|
|
const size_t initValue = 1049039;
|
||
|
|
const size_t A = 6665339;
|
||
|
|
const size_t B = 2534641;
|
||
|
|
size_t h = initValue;
|
||
|
|
for (char ch : sv)
|
||
|
|
h = (h * A) ^ (ch * B);
|
||
|
|
return h;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
#endif
|
||
|
|
} // namespace drogon
|
||
|
|
namespace std
|
||
|
|
{
|
||
|
|
template <>
|
||
|
|
struct hash<drogon::string_view>
|
||
|
|
{
|
||
|
|
size_t operator()(const drogon::string_view &__str) const noexcept
|
||
|
|
{
|
||
|
|
// MSVC is having problems with non-aligned strings
|
||
|
|
#ifndef _MSC_VER
|
||
|
|
return drogon::StringViewHasher<sizeof(size_t)>()(__str);
|
||
|
|
#else
|
||
|
|
return drogon::ShortStringViewHasher(__str);
|
||
|
|
#endif
|
||
|
|
}
|
||
|
|
};
|
||
|
|
} // namespace std
|
||
|
|
|
||
|
|
#endif
|