C++ 编译时字符串哈希

C++ 编译时字符串哈希,c++,metaprogramming,c++11,hash,C++,Metaprogramming,C++11,Hash,我在几个不同的地方读到过,使用C++11的新字符串文本,可以在编译时计算字符串的哈希值。然而,似乎没有人愿意站出来说这是可能的,也没有人愿意说这将如何实现 这可能吗 接线员长什么样 我对这样的用例特别感兴趣 void foo( const std::string& value ) { switch( std::hash(value) ) { case "one"_hash: one(); break; case "two"_hash: two()

我在几个不同的地方读到过,使用C++11的新字符串文本,可以在编译时计算字符串的哈希值。然而,似乎没有人愿意站出来说这是可能的,也没有人愿意说这将如何实现

  • 这可能吗
  • 接线员长什么样

我对这样的用例特别感兴趣

void foo( const std::string& value )
{
   switch( std::hash(value) )
   {
      case "one"_hash: one(); break;
      case "two"_hash: two(); break;
      /*many more cases*/
      default: other(); break;
   }
}

注意:编译时散列函数不必完全像我写的那样。我尽力猜测最终的解决方案是什么样的,但是
meta_hash::value
也可能是一个可行的解决方案。

请注意,此处显示的表单未被纳入标准,如下所述。

编译时字符串处理可以通过中建议的用户定义文本来实现。
正如我已经提到的,我不知道目前有任何编译器实现它,如果没有编译器支持,只能进行猜测工作

在本协议§2.13.7.3和§4中,我们有以下内容:

否则(S包含文本运算符模板),L将被视为形式调用
运算符“”X() 其中n是源字符序列c1c2…ck。[注:序列c1c2…ck可以 仅包含来自基本源字符集的字符。-结束说明]

将其与
constexpr
相结合,我们应该有编译时字符串处理

更新:我忽略了我读错了段落,此表单允许用于用户定义的整数文本和-浮点文本,但显然不允许用于-字符串文本(§2.13.7.5)。
提案的这一部分似乎没有被接受

话虽如此,我对C++0x的了解有限,但它可能看起来像这样(我很可能搞错了):


至少根据我对§7.1.5/3和§5.19的理解,以下内容可能是合法的:

unsigned constexpr const_hash(char const *input) {
    return *input ?
        static_cast<unsigned int>(*input) + 33 * const_hash(input + 1) :
        5381;
}
为了遵守§5.19/2/6/2的要求,您可能需要执行以下操作:

// one of the `constexpr`s is probably redundant, but I haven't figure out which.
char constexpr * constexpr v_one = "one"; 

// ....

case const_hash(v_one): one(); break;
  • 我使用额外的“斜线”数字来表示未编号的要点,因此这是第二个要点,如果§5.19/2中的第六个要点。我想我可能得和皮特·贝克尔谈谈,是否有可能在层次结构中添加一些数字/字母/罗马数字来识别这样的片段

  • 以下内容适用于GCC 4.6.1,您可以在开关块中使用
    hash
    pack

    /* Fast simple string hash (Bernstein?) */                                       
    constexpr unsigned int hash(const char *s, int off = 0) {                        
        return !s[off] ? 5381 : (hash(s, off+1)*33) ^ s[off];                           
    }                                                                                
    
    /* Pack the string into an unsigned int                                          
     * Using 7 bits (ascii) it packs 9 chars into a uint64_t                         
     */                                                                              
    template <class T = uint64_t, unsigned int Bits = 7>                             
    constexpr T pack(const char *s, unsigned int off = 0) {                          
        return (Bits*off >= CHAR_BIT*sizeof(T) || !s[off]) ? 0 :                     
            (((T)s[off] << (Bits*off)) | pack(s,off+1));                             
    }  
    
    /*快速简单字符串哈希(Bernstein?)*/
    constexpr无符号整数散列(const char*s,int off=0){
    return!s[off]?5381:(散列(s,off+1)*33)^s[off];
    }                                                                                
    /*将字符串打包为无符号整数
    *它使用7位(ascii)将9个字符打包到uint64\t中
    */                                                                              
    模板
    constexpr T pack(const char*s,unsigned int off=0){
    返回(位*off>=CHAR_位*sizeof(T)| |!s[off])?0:
    
    (((T)s[off]这有点晚了,但我使用
    constepr
    成功地实现了编译时CRC32函数。问题是在编写本文时,它只适用于GCC,而不适用于MSVC或Intel编译器

    以下是代码片段:

    // CRC32 Table (zlib polynomial)
    static constexpr uint32_t crc_table[256] = {
        0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
        0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
        0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
    ...
    };
    template<size_t idx>
    constexpr uint32_t crc32(const char * str)
    {
        return (crc32<idx-1>(str) >> 8) ^ crc_table[(crc32<idx-1>(str) ^ str[idx]) & 0x000000FF];
    }
    
    // This is the stop-recursion function
    template<>
    constexpr uint32_t crc32<size_t(-1)>(const char * str)
    {
        return 0xFFFFFFFF;
    }
    
    // This doesn't take into account the nul char
    #define COMPILE_TIME_CRC32_STR(x) (crc32<sizeof(x) - 2>(x) ^ 0xFFFFFFFF)
    
    enum TestEnum
    {
        CrcVal01 = COMPILE_TIME_CRC32_STR("stack-overflow"),
    };
    
    //CRC32表(zlib多项式)
    静态constexpr uint32\u t crc\u表[256]={
    0x00000000L、0x7707096L、0xee0e612cL、0x990951baL、0x076dc419L、,
    0x706af48fL、0xe963a535L、0x9e6495a3L、0x0edb8832L、0x79dcb8a4L、,
    0xe0d5e91eL、0x97d2d988L、0x09b64c2bL、0x7eb17cbdL、0xe7b82d07L、,
    ...
    };
    模板
    constexpr uint32\u t crc32(const char*str)
    {
    返回(crc32(str)>>8)^crc_表[(crc32(str)^str[idx])&0x000000FF];
    }
    //这是停止递归函数
    模板
    constexpr uint32\u t crc32(const char*str)
    {
    返回0xFFFFFF;
    }
    //这不考虑nul字符
    #定义编译时间CRC32 STR(x)(CRC32(x)^0xFFFFFF)
    测试枚举
    {
    CrcVal01=编译时间CRC32字符串(“堆栈溢出”),
    };
    
    CrcVal01
    等于0x335CC04A


    希望这能对您有所帮助!

    这段代码基于Clement JACOB的一段。但也适用于clang。而且它的编译速度应该更快(它只有一个递归调用,而不是像原始文章中那样有两个递归调用)

    #包括
    #包括
    #包括
    静态constexpr无符号整数crc_表[256]={
    0x00000000、0x7707096、0xee0e612c、0x990951ba、0x076dc419、0x706af48f、,
    0xe963a535、0x9e6495a3、0x0edb8832、0x79dcb8a4、0xe0d5e91e、0x97d2d988、,
    0x09b64c2b、0x7eb17cbd、0xe7b82d07、0x90bf1d91、0x1db71064、0x6ab020f2、,
    0xf3b97148、0x84be41de、0x1adad47d、0x6ddde4eb、0xf4d4b551、0x83d385c7、,
    0x136c9856、0x646ba8c0、0xfd62f97a、0x8a65c9ec、0x14015c4f、0x63066cd9、,
    0xfa0f3d63、0x8d080df5、0x3b6e20c8、0x4c69105e、0xd56041e4、0xa2677172、,
    0x3c03e4d1、0x4b04d447、0xd20d85fd、0xa50ab56b、0x35b5a8fa、0x42b2986c、,
    0xdbbbc9d6、0xacbcf940、0x32d86ce3、0x45df5c75、0xdcd60dcf、0xabd13d59、,
    0x26d930ac、0x51de003a、0xc8d75180、0xbfd06116、0x21b4f4b5、0x56b3c423、,
    0xcfba9599、0xb8bda50f、0x2802b89e、0x5f058808、0xc60cd9b2、0xb10be924、,
    0x2f6f7c87、0x58684c11、0xc1611dab、0xb6662d3d、0x76dc4190、0x01db7106、,
    0x98d220bc、0xefd5102a、0x71b18589、0x06b6b51f、0x9fbfe4a5、0xe8b8d433、,
    0x7807c9a2、0x0f00f934、0x9609a88e、0xe10e9818、0x7f6a0dbb、0x086d3d2d、,
    0x91646c97、0xe6635c01、0x6B6C51F4、0x1c6c6162、0x856530d8、0xf262004e、,
    0x6c0695ed、0x1b01a57b、0x8208f4c1、0xf50fc457、0x65b0d9c6、0x12b7e950、,
    0x8bbeb8ea、0xfcb9887c、0x62dd1ddf、0x15da2d49、0x8cd37cf3、0xfbd44c65、,
    0x4db26158、0x3ab551ce、0xa3bc0074、0xd4bb30e2、0x4adfa541、0x3dd895d7、,
    0xa4d1c46d,
    
    // one of the `constexpr`s is probably redundant, but I haven't figure out which.
    char constexpr * constexpr v_one = "one"; 
    
    // ....
    
    case const_hash(v_one): one(); break;
    
    /* Fast simple string hash (Bernstein?) */                                       
    constexpr unsigned int hash(const char *s, int off = 0) {                        
        return !s[off] ? 5381 : (hash(s, off+1)*33) ^ s[off];                           
    }                                                                                
    
    /* Pack the string into an unsigned int                                          
     * Using 7 bits (ascii) it packs 9 chars into a uint64_t                         
     */                                                                              
    template <class T = uint64_t, unsigned int Bits = 7>                             
    constexpr T pack(const char *s, unsigned int off = 0) {                          
        return (Bits*off >= CHAR_BIT*sizeof(T) || !s[off]) ? 0 :                     
            (((T)s[off] << (Bits*off)) | pack(s,off+1));                             
    }  
    
    // CRC32 Table (zlib polynomial)
    static constexpr uint32_t crc_table[256] = {
        0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
        0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
        0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
    ...
    };
    template<size_t idx>
    constexpr uint32_t crc32(const char * str)
    {
        return (crc32<idx-1>(str) >> 8) ^ crc_table[(crc32<idx-1>(str) ^ str[idx]) & 0x000000FF];
    }
    
    // This is the stop-recursion function
    template<>
    constexpr uint32_t crc32<size_t(-1)>(const char * str)
    {
        return 0xFFFFFFFF;
    }
    
    // This doesn't take into account the nul char
    #define COMPILE_TIME_CRC32_STR(x) (crc32<sizeof(x) - 2>(x) ^ 0xFFFFFFFF)
    
    enum TestEnum
    {
        CrcVal01 = COMPILE_TIME_CRC32_STR("stack-overflow"),
    };
    
    #include <iostream>
    #include <string>
    #include <vector>
    
    static constexpr unsigned int crc_table[256] = {
        0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
        0xe963a535, 0x9e6495a3,    0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
        0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
        0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
        0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
        0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
        0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
        0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
        0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
        0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
        0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
        0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
        0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
        0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
        0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
        0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
        0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
        0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
        0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
        0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
        0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
        0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
        0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
        0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
        0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
        0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
        0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
        0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
        0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
        0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
        0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
        0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
        0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
        0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
        0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
        0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
        0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
        0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
        0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
        0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
        0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
        0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
        0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
    };
    
    
    template<int size, int idx = 0, class dummy = void>
    struct MM{
      static constexpr unsigned int crc32(const char * str, unsigned int prev_crc = 0xFFFFFFFF)
      {
          return MM<size, idx+1>::crc32(str, (prev_crc >> 8) ^ crc_table[(prev_crc ^ str[idx]) & 0xFF] );
      }
    };
    
    // This is the stop-recursion function
    template<int size, class dummy>
    struct MM<size, size, dummy>{
      static constexpr unsigned int crc32(const char * str, unsigned int prev_crc = 0xFFFFFFFF)
      {
          return prev_crc^ 0xFFFFFFFF;
      }
    };
    
    // This don't take into account the nul char
    #define COMPILE_TIME_CRC32_STR(x) (MM<sizeof(x)-1>::crc32(x))
    
    
    template<unsigned int crc>
    void PrintCrc()
    {
        std::cout << crc << std::endl;
    }
    
    
    int main()
    {
    
        PrintCrc<COMPILE_TIME_CRC32_STR("HAH")>();
    }
    
    namespace my_hash {
      template<class>struct hasher;
      template<>
      struct hasher<std::string> {
        std::size_t constexpr operator()(char const *input)const {
          return *input ?
            static_cast<unsigned int>(*input) + 33 * (*this)(input + 1) :
            5381;
        }
        std::size_t operator()( const std::string& str ) const {
          return (*this)(str.c_str());
        }
      };
      template<typename T>
      std::size_t constexpr hash(T&& t) {
        return hasher< typename std::decay<T>::type >()(std::forward<T>(t));
      }
      inline namespace literals {
        std::size_t constexpr operator "" _hash(const char* s,size_t) {
          return hasher<std::string>()(s);
        }
      }
    }
    using namespace my_hash::literals;
    void one() {} void two() {} void other() {}
    
    void foo( const std::string& value )
    {
      switch( my_hash::hash(value) )
      {
        case "one"_hash: one(); break;
        case "two"_hash: two(); break;
        /*many more cases*/
        default: other(); break;
      }
    }
    
    namespace detail {
    // CRC32 Table (zlib polynomial)
    static constexpr uint32_t crc_table[256] = { 0x00000000L, 0x77073096L, ... }
    
    template<size_t idx>
    constexpr uint32_t combine_crc32(const char * str, uint32_t part) {
      return (part >> 8) ^ crc_table[(part ^ str[idx]) & 0x000000FF];
    }
    
    template<size_t idx>
    constexpr uint32_t crc32(const char * str) {
      return combine_crc32<idx>(str, crc32<idx - 1>(str));
    }
    
    // This is the stop-recursion function
    template<>
    constexpr uint32_t crc32<size_t(-1)>(const char * str) {
      return 0xFFFFFFFF;
    }
    
    } //namespace detail
    
    template <size_t len>
    constexpr uint32_t ctcrc32(const char (&str)[len]) {
      return detail::crc32<len - 2>(str) ^ 0xFFFFFFFF;
    }
    
    #include <functional>
    #include <cassert>
    using namespace std;
    
    
    constexpr size_t cx_hash(const char* input) {
        size_t hash = sizeof(size_t) == 8 ? 0xcbf29ce484222325 : 0x811c9dc5;
        const size_t prime = sizeof(size_t) == 8 ? 0x00000100000001b3 : 0x01000193;
    
        while (*input) {
            hash ^= static_cast<size_t>(*input);
            hash *= prime;
            ++input;
        }
    
        return hash;
    }
    
    
    int main() {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT */
    
        auto a = cx_hash("test");
        hash<string> func;
        auto b = func("test");
        assert(a == b);
    
        return 0;
    }
    
    namespace detail {
    
        // CRC32 Table (zlib polynomial)
        static constexpr uint32_t crc_table[256] = { 0x00000000L, 0x77073096L, ... };
    
        constexpr uint32_t combine_crc32(size_t idx, const char * str, uint32_t part) {
            return (part >> 8) ^ crc_table[(part ^ str[idx]) & 0x000000FF];
        }
    
        constexpr uint32_t crc32(size_t idx, const char * str) {
            return idx == size_t(-1) ? 
                0xFFFFFFFF : combine_crc32(idx, str, crc32(idx - 1, str));
        }
    }
    
    uint32_t ctcrc32(std::string const& str) {
        size_t len = str.size() + 1;
        return detail::crc32(len - 2, str.c_str()) ^ 0xFFFFFFFF;
    }
    
    template <size_t len>
    constexpr uint32_t ctcrc32(const char (&str)[len]) {
        return detail::crc32(len - 2, str) ^ 0xFFFFFFFF;
    }
    
    #include <inttypes.h>
    
    namespace detail
    {
        // CRC32 Table (zlib polynomial)
        static constexpr uint32_t crc_table[256] =
        {
            0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
            ...
        };
    
        constexpr uint32_t combine_crc32( const char c, uint32_t part )
        {
            return (part >> 8) ^ crc_table[(part ^ c) & 0x000000FF];
        }
    
        constexpr uint32_t crc32( const char * str, size_t idx )
        {
            return combine_crc32( str[idx], idx ? crc32( str, idx - 1 ) : 0xFFFFFFFF );
        }
    } //namespace detail
    
    constexpr uint32_t ctcrc32( const char* str, size_t len )
    {
        return detail::crc32( str, len ) ^ 0xFFFFFFFF;
    }
    
    size_t constexpr operator "" _hash( const char* str, size_t len )
    {
        return ctcrc32( str, len );
    }
    
    unsigned constexpr const_hash( char const *input )
    {
        return *input ?
            static_cast<unsigned int>(*input) + 33 * const_hash( input + 1 ) :
            5381;
    }
    size_t constexpr operator "" _hash( const char* str, size_t len )
    {
        return const_hash( str );
    }
    
    static constexpr uint32_t crc_table[256] =
        {
            0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
            0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
            0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
            0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
            0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
            0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
            0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
            0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
            0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
            0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
            0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
            0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
            0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
            0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
            0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
            0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
            0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
            0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
            0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
            0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
            0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
            0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
            0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
            0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
            0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
            0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
            0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
            0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
            0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
            0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
            0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
            0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
            0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
            0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
            0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
            0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
            0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
            0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
            0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
            0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
            0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
            0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
            0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
            0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
            0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
            0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
            0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
            0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
            0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
            0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
            0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
            0x2d02ef8dL
        };
    
    constexpr uint32_t crc32(std::string_view str)
    {
        uint32_t crc = 0xffffffff;
        for (auto c : str)
            crc = (crc >> 8) ^ crc_table[(crc ^ c) & 0xff];
        return crc ^ 0xffffffff;
    }
    
                    ;hdr->hash = NGX_EM_HASH("authorization");
    00007FFD36B8B7DE  mov         rax,qword ptr [rbp+4D8h]  
    00007FFD36B8B7E5  mov         rcx,4EEC63AFAD69E079h     ; Decimal=5687030035641917561 __int64
    00007FFD36B8B7EF  mov         qword ptr [rax],rcx 
    
                    ;hdr->hash = NGX_EM_HASH("authorization");
    00007FFD337FFE93  lea         rcx,[string "authorization" (07FFD33885ED0h)]  
    00007FFD337FFE9A  call        operator "" _hash (07FFD336B78ECh)  
    00007FFD337FFE9F  mov         rcx,qword ptr [rbp+4D8h]  
    00007FFD337FFEA6  mov         qword ptr [rcx],rax