Added decoding support to runtime decode.

decode_database.h

@@ -0,0 +1,126 @@
+#ifndef DECODE_DATABASE_H
+#define DECODE_DATABASE_H
+
+#include <string>
+#include <vector>
+#include <unordered_map>
+#include <cstdint>
+
+/**
+ * @brief Signal byte order used for runtime decoding.
+ */
+enum class ByteOrder {
+  Intel,
+  Motorola
+};
+
+/**
+ * @brief Signal numeric type.
+ */
+enum class ValueType {
+  Unsigned,
+  Signed
+};
+
+/**
+ * @brief Runtime-ready signal definition.
+ */
+struct DecodeSignal {
+  std::string name;                   /**< Signal name. */
+  std::uint32_t startBit;             /**< DBC start bit. */
+  std::uint32_t length;               /**< Signal length in bits. */
+  ByteOrder byteOrder;                /**< Intel or Motorola. */
+  ValueType valueType;                /**< Signed or unsigned. */
+  double factor;                      /**< Scaling factor. */
+  double offset;                      /**< Physical offset. */
+  double minimum;                     /**< Minimum physical value. */
+  double maximum;                     /**< Maximum physical value. */
+  std::string unit;                   /**< Physical unit. */
+  std::vector<std::string> receivers; /**< Receivers. */
+  std::string comment;                /**< Comment. */
+
+  DecodeSignal()
+    : name()
+    , startBit (0U)
+    , length (0U)
+    , byteOrder (ByteOrder::Intel)
+    , valueType (ValueType::Unsigned)
+    , factor (1.0)
+    , offset (0.0)
+    , minimum (0.0)
+    , maximum (0.0)
+    , unit()
+    , receivers()
+    , comment() {
+  }
+};
+
+/**
+ * @brief Runtime-ready frame definition.
+ */
+struct DecodeFrame {
+  std::string name;                /**< Frame name. */
+  std::uint32_t canId;             /**< Normalized CAN ID. */
+  bool isExtended;                 /**< true for extended frame. */
+  std::uint8_t dlc;                /**< Payload length. */
+  std::uint32_t pgn;               /**< PGN if available. */
+  bool hasPgn;                     /**< true if PGN is valid. */
+  std::string transmitter;         /**< Transmitter ECU. */
+  std::string comment;             /**< Frame comment. */
+  std::vector<DecodeSignal> signals; /**< Signal definitions. */
+
+  DecodeFrame()
+    : name()
+    , canId (0U)
+    , isExtended (false)
+    , dlc (0U)
+    , pgn (0U)
+    , hasPgn (false)
+    , transmitter()
+    , comment()
+    , signals() {
+  }
+};
+
+/**
+ * @brief Key for fast frame lookup.
+ */
+struct FrameKey {
+  std::uint32_t canId;
+  bool isExtended;
+
+  FrameKey()
+    : canId (0U)
+    , isExtended (false) {
+  }
+
+  FrameKey (std::uint32_t id, bool extended)
+    : canId (id)
+    , isExtended (extended) {
+  }
+
+  bool operator== (const FrameKey &other) const {
+    return (canId == other.canId) && (isExtended == other.isExtended);
+  }
+};
+
+/**
+ * @brief Hasher for frame key.
+ */
+struct FrameKeyHasher {
+  std::size_t operator() (const FrameKey &key) const {
+    const std::size_t a = static_cast<std::size_t> (key.canId);
+    const std::size_t b = key.isExtended ? 1U : 0U;
+    return (a * 1315423911U) ^ b;
+  }
+};
+
+/**
+ * @brief Runtime decode database with fast lookup by CAN ID.
+ */
+struct DecodeDatabase {
+  std::vector<DecodeFrame> frames;
+  std::unordered_map<FrameKey, std::size_t, FrameKeyHasher> frameIndexByKey;
+};
+
+#endif /* DECODE_DATABASE_H */