fsfw/contrib/fsfw_contrib/etl-20.39.4/test/test_pearson.cpp

/******************************************************************************
The MIT License(MIT)

Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com

Copyright(c) 2015 John Wellbelove

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#include "unit_test_framework.h"

#include <iterator>
#include <string>
#include <vector>
#include <iomanip>
#include <stdint.h>

#include "etl/pearson.h"

const size_t HASH_SIZE = 8;
typedef etl::pearson<HASH_SIZE>::value_type hash_t;

//***************************************************************************
/// Pearson lookup table
/// \ingroup pearson
//***************************************************************************
namespace etl
{
  static const uint8_t PEARSON_LOOKUP[] =
  {
    228,  39,  61,  95, 227, 187,   0, 197,  31, 189, 161, 222,  34,  15, 221, 246,
    19,  234,   6,  50, 113,   3,  91,  63,  77, 245, 144,   2, 183, 196,  25, 226,
    97,  126,  48,  59, 217,   4, 100, 145,  12,  88, 203, 149,  80, 154,  38,  27,
    224, 218, 158, 115, 202,  79,  53,  83, 242,  36, 139, 131, 136, 191,  42, 170,
    23,  99,  156,  51, 143,  60, 233, 206,  62, 108,  17,  67,  81,  71,  93, 195,
    26,  231, 247,  96,  24, 200, 176, 209, 152, 212, 138, 165,  75, 185, 130, 248,
    125, 110,  10, 116, 201,  90,  69, 204,  85, 251,  78, 157,  47, 184, 169, 141,
    134, 230,  89,  21, 146,  46,  55, 128, 148, 207, 216,  11, 114, 199, 103, 102,
    166, 244,   5, 104, 225, 160, 132,  28, 172,  65, 121, 140, 153, 119, 198, 210,
    58,  87,  117, 177,  33,  22,  13,  37,  49, 174, 109,  40,  73, 211,  18, 167,
    164, 252, 168,  74,  30, 173,  35,  98,  66, 193,  94, 175,  86,  54, 179, 122,
    220, 151, 192,  29, 133, 254, 155, 127, 240, 232, 190, 180,   8,  68, 236,  20,
    137,  92, 219, 208,  52, 250, 147, 142, 111, 112, 120,  45, 135, 255, 123, 229,
    57,  182, 243, 124, 186, 253,   7, 237,   9,  16,  70, 171, 235, 107, 223, 118,
    215, 178, 194, 181,  43, 188, 106, 105,  64, 241,  84, 238, 159,  44,  32,  76,
    213, 163, 150, 101, 129,  14, 249, 205, 214,   1,  41,  56, 162,  72, 239,  82
  };
}

//***************************************************************************
// Comparison calculator based on Wikipedia example. https://en.wikipedia.org/wiki/Pearson_hashing
//***************************************************************************
template <typename TContainer>
hash_t Pearson_Compare(const TContainer& data)
{
  hash_t hash;
  hash.fill(0);

  for (size_t j = 0UL; j < HASH_SIZE; ++j)
  {
    uint8_t subhash = etl::PEARSON_LOOKUP[(data[0] + j) % 256];

    for (size_t i = 1UL; i < data.size(); ++i)
    {
      subhash = etl::PEARSON_LOOKUP[subhash ^ data[i]];
    }

    hash[j] = subhash;
  }

  return hash;
}

//***************************************************************************
// Output stream for hash_t
//***************************************************************************
std::ostream& operator <<(std::ostream& os, const hash_t& hash)
{
  for (size_t i = 0UL; i < hash.size(); ++i)
  {
    os << int(hash[i]) << " ";
  }

  return os;
}

namespace
{
  SUITE(test_pearson)
  {
    //*************************************************************************
    TEST(test_pearson_constructor)
    {
      std::string data("123456789");

      hash_t compare = Pearson_Compare(data);
      hash_t hash    = etl::pearson<HASH_SIZE>(data.begin(), data.end());

      CHECK(compare == hash);
    }

    //*************************************************************************
    TEST(test_pearson_add_values)
    {
      std::string data("123456789");

      etl::pearson<HASH_SIZE> pearson_calculator;

      for (size_t i = 0UL; i < data.size(); ++i)
      {
        pearson_calculator.add(data[i]);
      }

      hash_t compare = Pearson_Compare(data);
      hash_t hash    = pearson_calculator;

      CHECK(compare == hash);
    }

    //*************************************************************************
    TEST(test_pearson_add_range)
    {
      std::string data("123456789");

      etl::pearson<HASH_SIZE> pearson_calculator;

      pearson_calculator.add(data.begin(), data.end());

      hash_t compare = Pearson_Compare(data);
      hash_t hash    = pearson_calculator.value();

      CHECK(compare == hash);
    }

    //*************************************************************************
    TEST(test_pearson_add_range_endian)
    {
      std::vector<uint8_t>  data1 = { 0x01U, 0x02U, 0x03U, 0x04U, 0x05U, 0x06U, 0x07U, 0x08U };
      std::vector<uint32_t> data2 = { 0x04030201UL, 0x08070605UL };
      std::vector<uint8_t>  data3 = { 0x08U, 0x07U, 0x06U, 0x05U, 0x04U, 0x03U, 0x02U, 0x01U };

      hash_t hash1 = etl::pearson<HASH_SIZE>(data1.begin(), data1.end());
      hash_t hash2 = etl::pearson<HASH_SIZE>((uint8_t*)&data2[0], (uint8_t*)(&data2[0] + data2.size()));
      CHECK(hash1 == hash2);

      hash_t hash3 = etl::pearson<HASH_SIZE>(data3.rbegin(), data3.rend());
      CHECK(hash1 == hash3);
    }
  };
}