telegram.hpp

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// © Copyright 2020, Septentrio NV/SA.
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#pragma once
 
// C++
#include <condition_variable>
#include <cstdint>
#include <mutex>
#include <queue>
#include <vector>
 
// ROSaic
#include <septentrio_gnss_driver/abstraction/typedefs.hpp>
 
static const uint8_t SYNC_BYTE_1 = 0x24;
static const uint8_t SBF_SYNC_BYTE_2 = 0x40;
static const uint8_t NMEA_SYNC_BYTE_2 = 0x47;
static const uint8_t NMEA_SYNC_BYTE_3 = 0x50;
static const uint8_t NMEA_INS_SYNC_BYTE_2 = 0x49;
static const uint8_t NMEA_INS_SYNC_BYTE_3 = 0x4E;
static const uint8_t RESPONSE_SYNC_BYTE_2 = 0x52;
static const uint8_t RESPONSE_SYNC_BYTE_3 = 0x3A;
static const uint8_t RESPONSE_SYNC_BYTE_3a = 0x21;
static const uint8_t ERROR_SYNC_BYTE_3 = 0x3F;
static const uint8_t CR = 0x0D;
static const uint8_t LF = 0x0A;
static const uint8_t CONNECTION_DESCRIPTOR_BYTE_I = 0x49;
static const uint8_t CONNECTION_DESCRIPTOR_BYTE_C = 0x43;
static const uint8_t CONNECTION_DESCRIPTOR_BYTE_U = 0x55;
static const uint8_t CONNECTION_DESCRIPTOR_BYTE_N = 0x4E;
static const uint8_t CONNECTION_DESCRIPTOR_BYTE_D = 0x44;
static const uint8_t CONNECTION_DESCRIPTOR_FOOTER = 0x3E;
 
static const uint16_t SBF_HEADER_SIZE = 8;
static const uint16_t MAX_SBF_SIZE = 65535;
static const uint16_t MAX_UDP_PACKET_SIZE = 65535;
 
namespace telegram_type {
    enum TelegramType
    {
        EMPTY,
        SBF,
        NMEA,
        NMEA_INS,
        RESPONSE,
        ERROR_RESPONSE,
        CONNECTION_DESCRIPTOR,
        UNKNOWN
    };
}
 
struct Telegram
{
    Timestamp stamp;
    telegram_type::TelegramType type;
    std::vector<uint8_t> message;
 
    Telegram(size_t preallocate = 3) noexcept :
        stamp(0), type(telegram_type::EMPTY),
        message(std::vector<uint8_t>(preallocate))
    {
    }
 
    ~Telegram() {}
 
    Telegram(const Telegram& other) noexcept :
        stamp(other.stamp), type(other.type), message(other.message)
    {
    }
 
    Telegram(Telegram&& other) noexcept :
        stamp(other.stamp), type(other.type), message(other.message)
    {
    }
 
    Telegram& operator=(const Telegram& other) noexcept
    {
        if (this != &other)
        {
            this->stamp = other.stamp;
            this->type = other.type;
            this->message = other.message;
        }
        return *this;
    }
 
    Telegram& operator=(Telegram&& other) noexcept
    {
        if (this != &other)
        {
            this->stamp = other.stamp;
            this->type = other.type;
            this->message = other.message;
        }
        return *this;
    }
};
 
template <typename T>
class ConcurrentQueue
{
public:
    [[nodiscard]] bool empty() const noexcept;
    [[nodiscard]] size_t size() const noexcept;
    void push(const T& input) noexcept;
    void pop(T& output) noexcept;
 
private:
    std::queue<T> queue_;
    std::condition_variable cond_;
    mutable std::mutex mtx_;
};
 
template <typename T>
[[nodiscard]] bool ConcurrentQueue<T>::empty() const noexcept
{
    std::lock_guard<std::mutex> lck(mtx_);
    return queue_.empty();
}
 
template <typename T>
[[nodiscard]] size_t ConcurrentQueue<T>::size() const noexcept
{
    std::lock_guard<std::mutex> lck(mtx_);
    return queue_.size();
}
 
template <typename T>
void ConcurrentQueue<T>::push(const T& input) noexcept
{
    {
        std::lock_guard<std::mutex> lck(mtx_);
        queue_.push(input);
    }
    cond_.notify_one();
}
 
template <typename T>
void ConcurrentQueue<T>::pop(T& output) noexcept
{
    std::unique_lock<std::mutex> lck(mtx_);
    cond_.wait(lck, [this] { return !queue_.empty(); });
    output = queue_.front();
    queue_.pop();
}
 
typedef ConcurrentQueue<std::shared_ptr<Telegram>> TelegramQueue;