jenkins.h

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/******************************************************************************
The MIT License(MIT)
 
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
 
Copyright(c) 2014 John Wellbelove
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files(the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
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The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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******************************************************************************/
 
#ifndef ETL_JENKINS_INCLUDED
#define ETL_JENKINS_INCLUDED
 
#include "platform.h"
#include "static_assert.h"
#include "type_traits.h"
#include "error_handler.h"
#include "ihash.h"
#include "frame_check_sequence.h"
#include "iterator.h"
 
#include <stdint.h>
 
#if defined(ETL_COMPILER_KEIL)
#pragma diag_suppress 1300
#endif

 
namespace etl
{
  //***************************************************************************
  //***************************************************************************
  struct jenkins_policy
  {
    typedef uint32_t value_type;
 
    uint32_t initial() const
    {
      is_finalised = false;
 
      return 0;
    }
 
    uint32_t add(value_type hash, uint8_t value) const
    {
      ETL_ASSERT(!is_finalised, ETL_ERROR(hash_finalised));
 
      hash += value;
      hash += (hash << 10U);
      hash ^= (hash >> 6U);
 
      return hash;
    }
 
    uint32_t final(value_type hash) const
    {
      hash += (hash << 3U);
      hash ^= (hash >> 11U);
      hash += (hash << 15U);
      is_finalised = true;
 
      return hash;
    }
 
    mutable bool is_finalised;
  };
 
  //*************************************************************************
  //*************************************************************************
  class jenkins : public etl::frame_check_sequence<etl::jenkins_policy>
  {
  public:
 
    //*************************************************************************
    //*************************************************************************
    jenkins()
    {
      this->reset();
    }
 
    //*************************************************************************
    //*************************************************************************
    template<typename TIterator>
    jenkins(TIterator begin, const TIterator end)
    {
      this->reset();
      this->add(begin, end);
    }
  };
}
 
#endif