From 304d7e8e32a45d4223ba833a7ca490ea810de2c0 Mon Sep 17 00:00:00 2001 From: Robin Mueller Date: Tue, 28 Sep 2021 15:30:31 +0200 Subject: [PATCH] space packet parser cleaned up, documentation --- src/fsfw/tmtcservices/SpacePacketParser.cpp | 2 +- src/fsfw/tmtcservices/SpacePacketParser.h | 100 ++++++++------------ 2 files changed, 42 insertions(+), 60 deletions(-) diff --git a/src/fsfw/tmtcservices/SpacePacketParser.cpp b/src/fsfw/tmtcservices/SpacePacketParser.cpp index 84f861cf..3d442458 100644 --- a/src/fsfw/tmtcservices/SpacePacketParser.cpp +++ b/src/fsfw/tmtcservices/SpacePacketParser.cpp @@ -44,7 +44,7 @@ ReturnValue_t SpacePacketParser::parseSpacePackets(const uint8_t **buffer, const foundSize = packetSize; } *buffer += foundSize; - readLen += foundSize; + readLen += idx + foundSize; return result; }; diff --git a/src/fsfw/tmtcservices/SpacePacketParser.h b/src/fsfw/tmtcservices/SpacePacketParser.h index 16b53ea4..82b15010 100644 --- a/src/fsfw/tmtcservices/SpacePacketParser.h +++ b/src/fsfw/tmtcservices/SpacePacketParser.h @@ -8,19 +8,11 @@ #include /** - * @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 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& 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 indexSizePairFIFO; - std::vector 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_ */