space packet parser cleaned up, documentation

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Robin Müller 2021-09-28 15:30:31 +02:00
parent f2020b2492
commit 304d7e8e32
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2 changed files with 42 additions and 60 deletions

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@ -44,7 +44,7 @@ ReturnValue_t SpacePacketParser::parseSpacePackets(const uint8_t **buffer, const
foundSize = packetSize;
}
*buffer += foundSize;
readLen += foundSize;
readLen += idx + foundSize;
return result;
};

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@ -8,19 +8,11 @@
#include <cstdint>
/**
* @brief This small helper class scans a given buffer for PUS packets.
* Can be used if PUS packets are serialized in a tightly packed frame.
* @brief This small helper class scans a given buffer for space packets.
* Can be used if space packets are serialized in a tightly packed frame.
* @details
* The parser uses the length field field of the space packets to find
* the respective space packet sizes.
*
* The parser parses a buffer by taking a pointer and the maximum size to scan.
* If space packets are found, they are stored in a FIFO which stores pairs
* consisting of the index in the buffer and the respective packet sizes.
*
* If the parser detects split packets (which means that the size of the
* next packet is larger than the remaining size to scan), it can either
* store that split packet or throw away the packet.
* The parser uses the length field field and the 16-bit TC packet ID of the space packets to find
* find space packets in a given data stream
* @author R. Mueller
*/
class SpacePacketParser {
@ -35,62 +27,52 @@ public:
/**
* @brief Parser constructor.
* @param maxExpectedPusPackets
* Maximum expected number of PUS packets. A good estimate is to divide
* the frame size by the minimum size of a PUS packet (12 bytes)
* @param storeSplitPackets
* Specifies whether split packets are also stored inside the FIFO,
* with the size being the remaining frame size.
* @param validPacketIds This vector contains the allowed 16-bit TC packet ID start markers
* The parser will search for these stark markers to detect the start of a space packet.
* It is also possible to pass an empty vector here, but this is not recommended.
* If an empty vector is passed, the parser will assume that the start of the given stream
* contains the start of a new space packet.
*/
SpacePacketParser(std::vector<uint16_t> validPacketIds);
/**
* Parse a given frame for space packets but also increment the given buffer and assign the
* total number of bytes read so far
* @param buffer Parser will look for space packets in this buffer
* @param maxSize Maximum size of the buffer
* @param startIndex Start index of a found space packet
* @param foundSize Found size of the space packet
* @param readLen Length read so far. This value is incremented by the number of parsed
* bytes which also includes the size of a found packet
* -@c NO_PACKET_FOUND if no packet was found in the given buffer or the length field is
* invalid. foundSize will be set to the size of the space packet header. buffer and
* readLen will be incremented accordingly.
* -@c SPLIT_PACKET if a packet was found but the detected size exceeds maxSize. foundSize
* will be set to the detected packet size and startIndex will be set to the start of the
* detected packet. buffer and read length will not be incremented but the found length
* will be assigned.
* -@c RETURN_OK if a packet was found
*/
ReturnValue_t parseSpacePackets(const uint8_t **buffer, const size_t maxSize,
size_t& startIndex, size_t& foundSize, size_t& readLen);
/**
* Parse a given frame for PUS packets
* @param frame
* @param frameSize
* @param foundPackets The number of found packets will be stored here
* @return
* -@c NO_PACKET_FOUND if no packet was found
* -@c SPLIT_PACKET if splitting is enabled and a split packet was found
* -@c RETURN_OK if a packet was found. The index and sizes are stored in the internal FIFO
* Parse a given frame for space packets
* @param buffer Parser will look for space packets in this buffer
* @param maxSize Maximum size of the buffer
* @param startIndex Start index of a found space packet
* @param foundSize Found size of the space packet
* -@c NO_PACKET_FOUND if no packet was found in the given buffer or the length field is
* invalid. foundSize will be set to the size of the space packet header
* -@c SPLIT_PACKET if a packet was found but the detected size exceeds maxSize. foundSize
* will be set to the detected packet size and startIndex will be set to the start of the
* detected packet
* -@c RETURN_OK if a packet was found
*/
ReturnValue_t parseSpacePackets(const uint8_t* buffer, const size_t maxSize,
size_t& startIndex, size_t& foundSize);
ReturnValue_t parseSpacePackets(const uint8_t **buffer, const size_t maxSize,
size_t& startIndex, size_t& foundSize, size_t& readLen);
/**
* Accessor function to get a reference to the internal FIFO which
* stores pairs of index and packet sizes. This FIFO is filled
* by the #parsePusPackets function.
* @return
*/
//DynamicFIFO<IndexSizePair>& fifo();
/**
* Retrieve the next index and packet size pair from the FIFO.
* This also removes it from the FIFO. Please note that if the FIFO
* is empty, an empty pair will be returned.
* @return
*/
//IndexSizePair getNextFifoPair();
private:
/**
* A FIFO is used to store information about multiple PUS packets
* inside the receive buffer. The maximum number of entries is defined
* by the first constructor argument.
*/
//DynamicFIFO<IndexSizePair> indexSizePairFIFO;
std::vector<uint16_t> validPacketIds;
//bool storeSplitPackets = false;
// ReturnValue_t readMultiplePackets(const uint8_t *frame, size_t frameSize,
// size_t startIndex, uint32_t& foundPackets);
// ReturnValue_t readNextPacket(const uint8_t *frame,
// size_t frameSize, size_t& startIndex, uint32_t& foundPackets);
};
#endif /* FRAMEWORK_TMTCSERVICES_PUSPARSER_H_ */