packetstream.hh

#ifndef PACKETSTREAM_HH
#define PACKETSTREAM_HH
 
#include <QObject>
#include "errorstack.hh"
 
class QIODevice;

class PacketStream : public QObject
{
  Q_OBJECT
 
protected:
  explicit PacketStream(QObject *parent = nullptr);
 
public:
  virtual ~PacketStream();

  virtual bool isOpen() const = 0;
  virtual void close() = 0;

  virtual bool receive(QByteArray &buffer, int timeout=-1, const ErrorStack &err=ErrorStack()) = 0;
  virtual bool send(const QByteArray& buffer, int timeout=-1, const ErrorStack &err=ErrorStack()) = 0;
};
 

class SlipStream: public PacketStream
{
  Q_OBJECT
 
public:
  SlipStream(QIODevice *device, QObject *parent=nullptr);
 
public:
  bool isOpen() const override;
  void close() override;
  bool receive(QByteArray &buffer, int timeout=-1, const ErrorStack &err=ErrorStack()) override;
  bool send(const QByteArray& buffer, int timeout=-1, const ErrorStack &err=ErrorStack()) override;
 
protected:
  QIODevice *_device;
  QByteArray _buffer;
 
private:
  static constexpr char END_OF_PACKET = '\xC0';
  static constexpr char ESCAPE = '\xDB';
  static constexpr char ESCAPED_C0 = '\xDC';
  static constexpr char ESCAPED_DB = '\xDD';
};
 
 
 
#endif // PACKETSTREAM_HH