Adds the sdi_toolBox library (temporary version)

sdi_toolBox_1.0.x/toolBox/sdi_toolBox/generic/crc.h

@@ -0,0 +1,163 @@
+/*
+{{copyright}} 
+*/
+
+/*
+{{version}} 
+*/
+
+/*
+{{license}} 
+*/
+
+#pragma once
+
+#include <cstdint>
+#include <span>
+
+namespace sdi_ToolBox::generic
+{
+//--------------------------------------------------------------
+/**
+ * @class CRC16_modbus
+ * @brief CRC16 calculator for the Modbus protocol.
+ *
+ * Provides both static and incremental interfaces to compute the CRC16 checksum
+ * as used in the Modbus protocol (polynomial 0xA001, initial value 0xFFFF).
+ *
+ * Usage examples:
+ * @code
+ * // One-shot CRC calculation
+ * std::array<uint8_t, 8> data = { ... };
+ * uint16_t crc = Crc16_modbus::computeCRC(data);
+ *
+ * // Incremental CRC calculation
+ * Crc16_modbus crcHandle;
+ * crcHandle.init();
+ * for (uint8_t b : data) {
+ *     crcHandle.update(b);
+ * }
+ * uint16_t crc = crcHandle.finalize();
+ * @endcode
+ */
+class CRC16_modbus
+{
+  static constexpr uint16_t INITIAL_VALUE = 0xFFFF;
+
+  public:
+  /**
+   * @brief Computes the CRC16 of the given data in one call.
+   * @param data The data buffer to compute the CRC for.
+   * @return The computed CRC16 value.
+   */
+  static uint16_t computeCRC(const std::span<const uint8_t> &data);
+
+  public:
+  CRC16_modbus()                                         = default;     // Default constructor
+  virtual ~CRC16_modbus()                                = default;     // Default destructor
+  CRC16_modbus(const CRC16_modbus &other)                = default;     // Copy constructor
+  CRC16_modbus(CRC16_modbus &&other) noexcept            = default;     // Move constructor
+  CRC16_modbus &operator=(const CRC16_modbus &other)     = default;     // Copy assignment
+  CRC16_modbus &operator=(CRC16_modbus &&other) noexcept = default;     // Move assignment
+
+  /**
+   * @brief Constructs and initializes the CRC with the given data.
+   * @param data The data buffer to initialize and update the CRC with.
+   */
+  explicit CRC16_modbus(const std::span<const uint8_t> &data);
+
+  /**
+   * @brief Initializes or re-initializes the CRC to the default value (0xFFFF).
+   */
+  void init();
+
+  /**
+   * @brief Updates the CRC with a single byte.
+   * @param val The byte value to update the CRC with.
+   */
+  void update(const uint8_t &val);
+
+  /**
+   * @brief Updates the CRC with a data buffer.
+   * @param data The data buffer to update the CRC with.
+   */
+  void update(const std::span<const uint8_t> &data);
+
+  /**
+   * @brief Finalizes the CRC calculation and returns the CRC value.
+   * @return The finalized CRC16 value.
+   */
+  uint16_t finalize() const;
+
+  /**
+   * @brief Returns the current CRC value.
+   * @return The current CRC16 value.
+   */
+  [[nodiscard]] uint16_t getCRC() const;
+
+  protected:
+  uint16_t m_crc = INITIAL_VALUE;     // Current CRC value
+};
+//--------------------------------------------------------------
+
+//--------------------------------------------------------------
+/* Compute CRC in one go */
+inline uint16_t CRC16_modbus::computeCRC(const std::span<const uint8_t> &data)
+{
+  const CRC16_modbus crc(data);
+  return crc.finalize();
+}
+//--------------------------------------------------------------
+/* Constructor */
+inline CRC16_modbus::CRC16_modbus(const std::span<const uint8_t> &data)
+{
+  init();
+  update(data);
+}
+//--------------------------------------------------------------
+/* Reinit crc handle */
+inline void CRC16_modbus::init()
+{
+  m_crc = INITIAL_VALUE;
+}
+//--------------------------------------------------------------
+/* Update CRC */
+inline void CRC16_modbus::update(const uint8_t &val)
+{
+  constexpr uint16_t PolynomialValue = 0xA001;
+
+  m_crc ^= static_cast<uint16_t>(val);     // XOR byte into least sig. byte of crc
+  for (int i = 8; i != 0; i--)             // Loop over each bit
+  {
+    if ((m_crc & 0x0001) != 0)     // If the LSB is set
+    {
+      m_crc >>= 1;     // Shift right and XOR PolynomialValue
+      m_crc ^= PolynomialValue;
+    }
+    else     // Else LSB is not set
+    {
+      m_crc >>= 1;     // Just shift right
+    }
+  }
+}
+//--------------------------------------------------------------
+/* Update CRC */
+inline void CRC16_modbus::update(const std::span<const uint8_t> &data)
+{
+  for (const auto &c : data)
+    update(c);
+}
+//--------------------------------------------------------------
+/* Finalize and return CRC value */
+inline uint16_t CRC16_modbus::finalize() const
+{
+  return getCRC();
+}
+//--------------------------------------------------------------
+/* Return CRC value */
+inline uint16_t CRC16_modbus::getCRC() const
+{
+  return m_crc;
+}
+//--------------------------------------------------------------
+}     // namespace sdi_ToolBox::generic