.. _program_listing_file_Source_Common_Inc_Utils_Hash.h:

Program Listing for File Hash.h
===============================

|exhale_lsh| :ref:`Return to documentation for file <file_Source_Common_Inc_Utils_Hash.h>` (``Source\Common\Inc\Utils\Hash.h``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #pragma once
   
   #include "Types.h"
   
   namespace Azura {
   constexpr SizeType DEFAULT_SEED{2166136261};
   constexpr SizeType DEFAULT_PRIME{0x01000193};
   
   constexpr SizeType FNVHash(const void* bytes, U32 numBytes, SizeType seed, SizeType prime) {
     const auto* ptr = static_cast<const unsigned char*>(bytes);
   
     SizeType hashValue = seed;
   
     for (auto itr = 0U; itr < numBytes; itr++) {
       hashValue = (ptr[itr] ^ hashValue) * prime;
     }
   
     return hashValue;
   }
   
   #define HASH(str) FNVHash(str, sizeof(str), DEFAULT_SEED, DEFAULT_PRIME)
   
   class HashOperator {
    public:
     virtual ~HashOperator() = default;
     HashOperator()          = default;
   
     HashOperator(const HashOperator& other)     = default;
     HashOperator(HashOperator&& other) noexcept = default;
     HashOperator& operator=(const HashOperator& other) = default;
     HashOperator& operator=(HashOperator&& other) noexcept = default;
   
     HashOperator(SizeType seed);
     virtual SizeType evaluate(const void* bytes, U32 numBytes) const = 0;
     virtual SizeType evaluate(const char* bytes, U32 len) const      = 0;
     virtual SizeType evaluate(const int& num) const                  = 0;
   
    protected:
      SizeType mSeed{2166136261};
   };
   
   class FNVHashOperator : public HashOperator {
     SizeType mPrime{0x01000193};  // 16777619
    public:
     FNVHashOperator() = default;
     FNVHashOperator(SizeType seed);
     FNVHashOperator(SizeType seed, SizeType prime);
     SizeType evaluate(const void* bytes, U32 numBytes) const override;
     SizeType evaluate(const char* bytes, U32 len) const override;
     SizeType evaluate(const int& num) const override;
   };
   }  // namespace Azura