Parsing message

.github/workflows/tests.yml

@@ -16,11 +16,20 @@ jobs:
     steps:
     - uses: actions/checkout@v3
 
+    - name: install fast_float dependency
+      run: |
+        cd ${{github.workspace}}
+        git clone https://github.com/fastfloat/fast_float.git
+        mkdir fast_float/build
+        cd fast_float/build
+        cmake -DCMAKE_INSTALL_PREFIX="${{github.workspace}}/installation" ..
+        make install
+
     - name: Configure CMake
       run: |
         mkdir build
         cd build
-        cmake -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} ..
+        cmake -DFastFloat_DIR="${{github.workspace}}/installation/share/cmake/FastFloat" -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} ..
 
     - name: Build
       run: |

CMakeLists.txt

@@ -1,5 +1,4 @@
-cmake_minimum_required(VERSION 3.23)
-# FILE_SET needs cmake 3.23
+cmake_minimum_required(VERSION 3.16)
 
 project(dbc VERSION 0.1.1 DESCRIPTION "C++ DBC Parser")
 
@@ -21,6 +20,17 @@ include(GNUInstallDirs)
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED True)
 
+find_package(FastFloat QUIET)
+if (NOT ${FastFloat_FOUND})
+    include(FetchContent)
+    FetchContent_Declare(
+      FastFloat
+      GIT_REPOSITORY https://github.com/fastfloat/fast_float.git
+      GIT_TAG 1ea4f27b2aeee2859a1354a3c24cff52a116cad1
+    )
+    FetchContent_MakeAvailable(FastFloat)
+endif()
+
 set(GCC_COMPILE_FLAGS "-Wextra -Wall -Wfloat-equal -Wundef -Wshadow \
 -Wpointer-arith -Wcast-align -Wstrict-prototypes -Wwrite-strings \
 -Waggregate-return -Wcast-qual -Wswitch-default -Wswitch-enum -Wconversion \
@@ -60,10 +70,14 @@ endif()
 add_subdirectory(doc)
 
 add_library(${PROJECT_NAME} STATIC ${SOURCE})
-target_sources(${PROJECT_NAME} INTERFACE FILE_SET HEADERS
-	TYPE HEADERS
-	BASE_DIRS ${PROJECT_SOURCE_DIR}/include/libdbc
-	FILES ${HEADER_FILES})
+target_link_libraries(${PROJECT_NAME} FastFloat::fast_float)
+
+if (${CMAKE_MINOR_VERSION} GREATER_EQUAL 23)
+    target_sources(${PROJECT_NAME} INTERFACE FILE_SET HEADERS
+            TYPE HEADERS
+            BASE_DIRS ${PROJECT_SOURCE_DIR}/include/libdbc
+            FILES ${HEADER_FILES})
+endif()
 
 add_custom_target(release
 					WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
@@ -76,11 +90,15 @@ install(TARGETS ${PROJECT_NAME}
 		DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
 # install headers
-install(TARGETS ${PROJECT_NAME}
-		FILE_SET HEADERS
-		DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/lib${PROJECT_NAME}
-		INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-)
+if (${CMAKE_MINOR_VERSION} GREATER_EQUAL 23)
+    install(TARGETS ${PROJECT_NAME}
+                    FILE_SET HEADERS
+                    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/lib${PROJECT_NAME}
+                    INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+    )
+else()
+    install(DIRECTORY ${PROJECT_SOURCE_DIR}/include/libdbc DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+endif()
 
 # Generate pkg-config file
 configure_file(${PROJECT_NAME}.pc.in ${PROJECT_NAME}.pc @ONLY)

doc/CMakeLists.txt

@@ -13,6 +13,7 @@ if(BUILD_DOCUMENTATION)
     configure_file(${doxyfile_in} ${doxyfile} @ONLY)
 
     add_custom_target(doc
+        ALL
         COMMAND ${DOXYGEN_EXECUTABLE} ${doxyfile}
         WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
         COMMENT "Generating API documentation with Doxygen"

include/libdbc/dbc.hpp

@@ -24,7 +24,7 @@ namespace libdbc {
 
 	class DbcParser : public Parser {
 	public:
-		DbcParser();
+        DbcParser();
 
 		virtual ~DbcParser() = default;
 
@@ -34,6 +34,8 @@ namespace libdbc {
 		std::vector<std::string> get_nodes() const;
 		std::vector<libdbc::Message> get_messages() const;
 
+        Message::ParseSignalsStatus parseMessage(const uint32_t id, const std::vector<uint8_t>& data, std::vector<double>& out_values);
+
 	private:
 		std::string version;
 		std::vector<std::string> nodes;

include/libdbc/message.hpp

@@ -3,21 +3,45 @@
 
 #include <string>
 #include <vector>
+#include <array>
 #include <iostream>
 #include <libdbc/signal.hpp>
 
 namespace libdbc {
 	struct Message {
-		uint32_t id;
-		std::string name;
-		uint8_t size;
-		std::string node;
-		std::vector<Signal> signals;
-
 		Message() = delete;
 		explicit Message(uint32_t id, const std::string& name, uint8_t size, const std::string& node);
 
-		virtual bool operator==(const Message& rhs) const;
+        enum class ParseSignalsStatus {
+            Success,
+            ErrorMessageToLong,
+            ErrorBigEndian,
+            ErrorUnknownID,
+            ErrorInvalidConversion,
+        };
+
+        /*!
+         * \brief parseSignals
+         * \param data
+         * \param values
+         * \return
+         */
+        ParseSignalsStatus parseSignals(const std::vector<uint8_t>& data, std::vector<double> &values) const;
+
+        void appendSignal(const Signal& signal);
+        const std::vector<Signal> signals() const;
+        uint32_t id() const;
+
+        virtual bool operator==(const Message& rhs) const;
+
+    private:
+        uint32_t m_id;
+        std::string m_name;
+        uint8_t m_size;
+        std::string m_node;
+        std::vector<Signal> m_signals;
+
+        friend std::ostream& operator<<(std::ostream& os, const Message& dt);
 	};
 
 	std::ostream& operator<< (std::ostream &out, const Message& msg);

include/libdbc/signal.hpp

@@ -25,6 +25,7 @@ namespace libdbc {
 		explicit Signal(std::string name, bool is_multiplexed, uint32_t start_bit, uint32_t size, bool is_bigendian, bool is_signed, double factor, double offset, double min, double max, std::string unit, std::vector<std::string> recievers);
 
 		virtual bool operator==(const Signal& rhs) const;
+        bool operator< (const Signal& rhs) const;
 	};
 
 	std::ostream& operator<< (std::ostream &out, const Signal& sig);

src/dbc.cpp

@@ -1,6 +1,7 @@
 #include <libdbc/exceptions/error.hpp>
 #include <libdbc/utils/utils.hpp>
 #include <libdbc/dbc.hpp>
+#include <fast_float/fast_float.h>
 
 #include <regex>
 
@@ -28,12 +29,12 @@ const auto whiteSpace = "\\s";
 
 namespace libdbc {
 
-	DbcParser::DbcParser() : version(""), nodes(),
+    DbcParser::DbcParser() : version(""), nodes(),
 				version_re("^(VERSION)\\s\"(.*)\""), bit_timing_re("^(BS_:)"),
 				name_space_re("^(NS_)\\s\\:"), node_re("^(BU_:)\\s((?:[\\w]+?\\s?)*)"),
 				message_re("^(BO_)\\s(\\d+)\\s(\\w+)\\:\\s(\\d+)\\s(\\w+|Vector__XXX)"),
 				// NOTE: No multiplex support yet
-                signal_re(std::string(whiteSpace) +
+                signal_re(std::string("^") + whiteSpace +
                           signalIdentifierPattern +
                           whiteSpace +
                           namePattern +
@@ -57,11 +58,13 @@ namespace libdbc {
 
 	}
 
-	void DbcParser::parse_file(const std::string& file) {
+    void DbcParser::parse_file(const std::string& file) {
 		std::ifstream s(file.c_str());
 		std::string line;
 		std::vector<std::string> lines;
 
+        messages.clear();
+
 		parse_dbc_header(s);
 
 		parse_dbc_nodes(s);
@@ -71,8 +74,7 @@ namespace libdbc {
 			lines.push_back(line);
 		}
 
-		parse_dbc_messages(lines);
-
+		parse_dbc_messages(lines);       
 	}
 
 	std::string DbcParser::get_version() const {
@@ -87,6 +89,13 @@ namespace libdbc {
 		return messages;
 	}
 
+    Message::ParseSignalsStatus DbcParser::parseMessage(const uint32_t id, const std::vector<uint8_t>& data, std::vector<double>& out_values) {
+        for (const auto& message: messages) {
+            if (message.id() == id)
+                return message.parseSignals(data, out_values);
+        }
+        return Message::ParseSignalsStatus::ErrorUnknownID;
+    }
 
 	void DbcParser::parse_dbc_header(std::istream& file_stream) {
 		std::string line;
@@ -150,17 +159,21 @@ namespace libdbc {
 				bool is_bigendian = (std::stoul(match.str(5)) == 0);
 				bool is_signed = (match.str(6) == "-");
 				// Alternate groups because a group is for the decimal portion
-				double factor = std::stod(match.str(7));
-				double offset = std::stod(match.str(9));
-				double min = std::stod(match.str(11));
-				double max = std::stod(match.str(13));
+                double factor;
+                fast_float::from_chars(match.str(7).data(), match.str(7).data() + match.str(7).size(), factor);
+                double offset;
+                fast_float::from_chars(match.str(9).data(), match.str(9).data() + match.str(9).size(), offset);
+                double min;
+                fast_float::from_chars(match.str(11).data(), match.str(11).data() + match.str(11).size(), min);
+                double max;
+                fast_float::from_chars(match.str(13).data(), match.str(13).data() + match.str(13).size(), max);
 				std::string unit = match.str(15);
 
 				std::vector<std::string> receivers;
 				utils::String::split(match.str(16), receivers, ',');
 
 				Signal sig(name, is_multiplexed, start_bit, size, is_bigendian, is_signed, factor, offset, min, max, unit, receivers);
-				messages.back().signals.push_back(sig);
+                messages.back().appendSignal(sig);
 			}
 		}
 

src/message.cpp

@@ -1,19 +1,73 @@
+#include <algorithm>
 #include <libdbc/message.hpp>
 
 namespace libdbc {
 	Message::Message(uint32_t id, const std::string& name, uint8_t size, const std::string& node) :
-		id(id), name(name), size(size), node(node) {}
+        m_id(id), m_name(name), m_size(size), m_node(node) {}
 
 	bool Message::operator==(const Message& rhs) const {
-		return (this->id == rhs.id) && (this->name == rhs.name) &&
-			   (this->size == rhs.size) && (this->node == rhs.node);
-	}
+        return (m_id == rhs.id()) && (m_name == rhs.m_name) &&
+               (m_size == rhs.m_size) && (m_node == rhs.m_node);
+    }
+
+    Message::ParseSignalsStatus Message::parseSignals(const std::vector<uint8_t>& data, std::vector<double>& values) const {
+        int size = data.size();
+        if (size > 8)
+            return ParseSignalsStatus::ErrorMessageToLong; // not supported yet
+
+        uint64_t data_little_endian = 0;
+        uint64_t data_big_endian = 0;
+        for (int i=0; i < size; i++) {
+            data_little_endian |= ((uint64_t)data[i]) << i * 8;
+            data_big_endian = (data_big_endian << 8) | (uint64_t)data[i];
+        }
+
+        // TODO: does this also work on a big endian machine?
+
+        const uint32_t len = size * 8;
+        uint64_t v = 0;
+        for (const auto& signal: m_signals) {
+            if (signal.is_bigendian) {
+                uint32_t start_bit = 8* (signal.start_bit / 8) + (7 - (signal.start_bit % 8)); // Calculation taken from python CAN
+                v = data_big_endian << start_bit;
+                v = v >> (len - signal.size);
+            } else {
+                const uint32_t shiftLeft = (len - (signal.size + signal.start_bit));
+                v = data_little_endian << shiftLeft;
+                v = v >> (shiftLeft + signal.start_bit);
+            }
+
+            if (signal.is_signed && signal.size > 1) {
+                switch (signal.size) {
+                case 8: values.push_back((int8_t)v * signal.factor + signal.offset); break;
+                case 16: values.push_back((int16_t)v * signal.factor + signal.offset); break;
+                case 32: values.push_back((int32_t)v * signal.factor + signal.offset); break;
+                case 64: values.push_back((int64_t)v * signal.factor + signal.offset); break;
+                default: return ParseSignalsStatus::ErrorInvalidConversion;
+                }
+            } else
+              values.push_back(v * signal.factor + signal.offset);
+        }
+        return ParseSignalsStatus::Success;
+    }
+
+    void Message::appendSignal(const Signal& signal) {
+        m_signals.push_back(signal);
+    }
+
+    const std::vector<Signal> Message::signals() const {
+       return m_signals;
+    }
+
+    uint32_t Message::id() const {
+        return m_id;
+    }
 
-	std::ostream& operator<< (std::ostream &out, const Message& msg) {
-		out << "Message: {id: " << msg.id << ", ";
-		out << "name: " << msg.name << ", ";
-		out << "size: " << msg.size << ", ";
-		out << "node: " << msg.node << "}";
+    std::ostream& operator<< (std::ostream &out, const Message& msg) {
+        out << "Message: {id: " << msg.id() << ", ";
+        out << "name: " << msg.m_name << ", ";
+        out << "size: " << msg.m_size << ", ";
+        out << "node: " << msg.m_node << "}";
 		return out;
 	}
-}
+}

src/signal.cpp

@@ -12,6 +12,9 @@ namespace libdbc {
 			   (this->unit == rhs.unit) && (this->receivers == rhs.receivers);
 	}
 
+    bool Signal::operator< (const Signal& rhs) const {
+        return start_bit < rhs.start_bit;
+    }
 
 	std::ostream& operator<< (std::ostream &out, const Signal& sig) {
 		out << "Signal {name: " << sig.name << ", ";

src/utils.cpp

@@ -72,4 +72,4 @@ namespace utils {
 		return start == end ? std::string() : line.substr(start, end - start + 1);
 	}
 
-}	// Namespace Utils
+}	// Namespace Utils