archives.hpp

#ifndef ARCHIVES_HPP_TLVURDQK
#define ARCHIVES_HPP_TLVURDQK
 
#include <vanetza/common/byte_order.hpp>
#include <exception>
#include <istream>
#include <ostream>
#include <streambuf>
 
namespace vanetza
{
 
/**
 * This is a drop-in replacement for boost::archive::binary_iarchive
 */
class InputArchive
{
public:
    using InputStream = std::basic_istream<char>;
    using StreamBuffer = std::basic_streambuf<char>;
    class Exception : public std::runtime_error {
        using std::runtime_error::runtime_error;
    };
 
    enum class ErrorCode {
        Ok,
        IncompleteData,
        ExcessiveLength,
        ConstraintViolation,
    };
 
    InputArchive(InputStream& is);
    InputArchive(StreamBuffer& buf);
 
    template<typename T>
    InputArchive& operator>>(T& t)
    {
        static_assert(std::is_integral<T>::value == true, "only integral types are supported");
        char* ptr = reinterpret_cast<char*>(&t);
        load_binary(ptr, sizeof(T));
        return *this;
    }
 
    void load_binary(unsigned char* data, std::size_t len);
    void load_binary(char* data, std::size_t len);
    char peek_byte();
    std::size_t remaining_bytes();
 
    bool is_good() const;
    ErrorCode error_code() const;
    void fail(ErrorCode error_code);
 
private:
    StreamBuffer* m_stream_buffer;
    ErrorCode m_error_code = ErrorCode::Ok;
};
 
/**
 * This is a drop-in replacement for boost::archive::binary_oarchive
 */
class OutputArchive
{
public:
    using OutputStream = std::basic_ostream<char>;
    using StreamBuffer = std::basic_streambuf<char>;
    class Exception : public std::runtime_error {
        using std::runtime_error::runtime_error;
    };
 
    OutputArchive(OutputStream& os);
    OutputArchive(StreamBuffer& buf);
 
    template<typename T>
    OutputArchive& operator<<(const T& t)
    {
        static_assert(std::is_integral<T>::value == true, "only integral types are supported");
        const char* ptr = reinterpret_cast<const char*>(&t);
        save_binary(ptr, sizeof(T));
        return *this;
    }
 
    void save_binary(const unsigned char* data, std::size_t len);
    void save_binary(const char* data, std::size_t len);
 
private:
    StreamBuffer* m_stream_buffer;
};
 
} // namespace vanetza
 
#endif /* ARCHIVES_HPP_TLVURDQK */