72 lines
2.5 KiB
C++
72 lines
2.5 KiB
C++
#ifndef FRAMEWORK_GLOBALFUNCTIONS_DLEENCODER_H_
|
|
#define FRAMEWORK_GLOBALFUNCTIONS_DLEENCODER_H_
|
|
|
|
#include <framework/returnvalues/HasReturnvaluesIF.h>
|
|
#include <cstddef>
|
|
|
|
/**
|
|
* @brief This DLE Encoder (Data Link Encoder) can be used to encode and
|
|
* decode arbitrary data with ASCII control characters
|
|
* @details
|
|
* List of control codes:
|
|
* https://en.wikipedia.org/wiki/C0_and_C1_control_codes
|
|
*
|
|
* This encoder can be used to achieve a basic transport layer when using
|
|
* char based transmission systems.
|
|
* The passed source strean is converted into a encoded stream by adding
|
|
* a STX marker at the startr of the stream and an ETX marker at the end of
|
|
* the stream. Any STX, ETX and DLE occurences in the source stream are escaped
|
|
* by a DLE character.
|
|
*/
|
|
class DleEncoder: public HasReturnvaluesIF {
|
|
private:
|
|
DleEncoder();
|
|
virtual ~DleEncoder();
|
|
|
|
public:
|
|
static constexpr uint8_t INTERFACE_ID = CLASS_ID::DLE_ENCODER;
|
|
static constexpr ReturnValue_t STREAM_TOO_SHORT = MAKE_RETURN_CODE(0x01);
|
|
static constexpr ReturnValue_t DECODING_ERROR = MAKE_RETURN_CODE(0x02);
|
|
|
|
//! Start Of Text character. First character is encoded stream
|
|
static const uint8_t STX = 0x02;
|
|
//! End Of Text character. Last character in encoded stream
|
|
static const uint8_t ETX = 0x03;
|
|
//! Data Link Escape character. Used to escape STX, ETX and DLE occurences
|
|
//! in the source stream.
|
|
static const uint8_t DLE = 0x10;
|
|
|
|
/**
|
|
* Encodes the give data stream by preceding it with the STX marker
|
|
* and ending it with an ETX marker. STX, ETX and DLE characters inside
|
|
* the stream are escaped by DLE characters.
|
|
* @param sourceStream
|
|
* @param sourceLen
|
|
* @param destStream
|
|
* @param maxDestLen
|
|
* @param encodedLen
|
|
* @param addStxEtx
|
|
* Adding STX and ETX can be omitted, if they are added manually.
|
|
* @return
|
|
*/
|
|
static ReturnValue_t encode(const uint8_t *sourceStream, size_t sourceLen,
|
|
uint8_t *destStream, size_t maxDestLen, size_t *encodedLen,
|
|
bool addStxEtx = true);
|
|
|
|
/**
|
|
* Converts an encoded stream back
|
|
* @param sourceStream
|
|
* @param sourceStreamLen
|
|
* @param readLen
|
|
* @param destStream
|
|
* @param maxDestStreamlen
|
|
* @param decodedLen
|
|
* @return
|
|
*/
|
|
static ReturnValue_t decode(const uint8_t *sourceStream,
|
|
size_t sourceStreamLen, size_t *readLen, uint8_t *destStream,
|
|
size_t maxDestStreamlen, size_t *decodedLen);
|
|
};
|
|
|
|
#endif /* FRAMEWORK_GLOBALFUNCTIONS_DLEENCODER_H_ */
|