git subrepo clone --branch=20.41.6 git@github.com:ETLCPP/etl.git components/etl

subrepo:
  subdir:   "components/etl"
  merged:   "be5537ec"
upstream:
  origin:   "git@github.com:ETLCPP/etl.git"
  branch:   "20.41.6"
  commit:   "be5537ec"
git-subrepo:
  version:  "0.4.9"
  origin:   "???"
  commit:   "???"

components/etl/test/test_xor_checksum.cpp

@@ -0,0 +1,149 @@
+/******************************************************************************
+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
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions :
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+******************************************************************************/
+
+#include "unit_test_framework.h"
+
+#include <iterator>
+#include <string>
+#include <vector>
+#include <stdint.h>
+
+#include "etl/checksum.h"
+
+namespace
+{
+  template <typename TSum, typename TIterator>
+  TSum reference_checksum(TIterator begin, TIterator end)
+  {
+    typedef typename std::iterator_traits<TIterator>::value_type value_type;
+    TSum checksum = 0;
+
+    while (begin != end)
+    {
+      value_type value = *begin++;
+      checksum ^= value;
+    }
+
+    return checksum;
+  }
+
+  SUITE(test_checksum)
+  {
+    //*************************************************************************
+    TEST(test_checksum_constructor)
+    {
+      std::string data("123456789");
+
+      uint8_t sum     = etl::xor_checksum<uint8_t>(data.begin(), data.end());
+      uint8_t compare = reference_checksum<uint8_t>(data.begin(), data.end());
+
+      CHECK_EQUAL(int(compare), int(sum));
+    }
+
+    //*************************************************************************
+    TEST(test_checksum_add_values8_add)
+    {
+      std::string data("123456789");
+
+      etl::xor_checksum<uint8_t> checksum_calculator;
+
+      for (size_t i = 0UL; i < data.size(); ++i)
+      {
+        checksum_calculator.add(data[i]);
+      }
+
+      uint8_t sum     = checksum_calculator;
+      uint8_t compare = reference_checksum<uint8_t>(data.begin(), data.end());
+
+      CHECK_EQUAL(int(compare), int(sum));
+    }
+
+    //*************************************************************************
+    TEST(test_checksum_add_values8_operator_plus_equals)
+    {
+      std::string data("123456789");
+
+      etl::xor_checksum<uint8_t> checksum_calculator;
+
+      for (size_t i = 0UL; i < data.size(); ++i)
+      {
+        checksum_calculator.add(data[i]);
+      }
+
+      uint8_t sum     = checksum_calculator;
+      uint8_t compare = reference_checksum<uint8_t>(data.begin(), data.end());
+
+      CHECK_EQUAL(int(compare), int(sum));
+    }
+
+    //*************************************************************************
+    TEST(test_checksum_add_range)
+    {
+      std::string data("123456789");
+
+      etl::xor_checksum<uint8_t> checksum_calculator;
+
+      checksum_calculator.add(data.begin(), data.end());
+
+      uint8_t sum     = checksum_calculator.value();
+      uint8_t compare = reference_checksum<uint8_t>(data.begin(), data.end());
+
+      CHECK_EQUAL(int(compare), int(sum));
+    }
+
+    //*************************************************************************
+    TEST(test_checksum_add_range_sum32)
+    {
+      std::string data("1");
+
+      etl::xor_checksum<uint32_t> checksum_calculator;
+
+      checksum_calculator.add(data.begin(), data.end());
+
+      uint32_t sum     = checksum_calculator.value();
+      uint32_t compare = reference_checksum<uint32_t>(data.begin(), data.end());
+
+      CHECK_EQUAL(compare, sum);
+    }
+
+    //*************************************************************************
+    TEST(test_checksum_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 };
+
+      uint64_t hash1 = etl::xor_checksum<uint8_t>(data1.begin(), data1.end());
+      uint64_t hash2 = etl::xor_checksum<uint8_t>((uint8_t*)&data2[0], (uint8_t*)&data2[0] + (data2.size() * sizeof(uint32_t)));
+      uint64_t hash3 = etl::xor_checksum<uint8_t>(data3.rbegin(), data3.rend());
+      CHECK_EQUAL(hash1, hash2);
+      CHECK_EQUAL(hash1, hash3);
+    }
+  };
+}
+