dcc::LogonFeedbackParser Class Reference

Parser for RailCom feedback that recognizes logon messages. More...

#include <LogonFeedback.hxx>

Inheritance diagram for dcc::LogonFeedbackParser:

Public Types
using	PacketType = LogonFeedbackCallbacks::PacketType
Public Types inherited from FlowInterface< MessageType >
typedef MessageType	message_type
	Stores the message template type for external reference.

Public Member Functions
	LogonFeedbackParser (LogonFeedbackCallbacks *cb, RailcomHubFlow *hub)
	Constructor.
void	send (Buffer< RailcomHubData > *b, unsigned priority) override
	Receives railcom feedback.
Public Member Functions inherited from FlowInterface< MessageType >
virtual Pool *	pool ()
virtual void	send (MessageType *message, unsigned priority=UINT_MAX)=0
	Entry point to the flow.
virtual MessageType *	type_helper ()
	This function is never user in the code, but GDB can use it to infer the correct message types.
MessageType *	alloc ()
	Synchronously allocates a message buffer from the pool of this flow.
void	alloc_async (Executable *target)
	Asynchronously allocates a message buffer from the pool of this flow.

Private Types
enum	Errors {   ERROR_SHIFT = 56 , ERROR_MASK = 0xffULL << ERROR_SHIFT , LENGTH_SHIFT = 48 , LENGTH_OFFSET = 1ULL << LENGTH_SHIFT ,   LENGTH_MASK = 0xffULL << LENGTH_SHIFT , PAYLOAD_MASK = LENGTH_OFFSET - 1 , ERROR_MISSING_DATA = 1ULL << ERROR_SHIFT , ERROR_ACK = 2ULL << ERROR_SHIFT ,   ERROR_OUT_OF_ORDER = 4ULL << ERROR_SHIFT , ERROR_GARBAGE = 8ULL << ERROR_SHIFT , ERROR_UNKNOWN = 16ULL << ERROR_SHIFT }

Static Private Member Functions
static void	append_data (uint64_t &data, unsigned &shift, uint8_t next_byte)
	Appends 6 bits of incoming data from railcom.
static uint64_t	parse_code (const Feedback *fb)
	Parses a concatenated ch1+ch2 response into a single uint64_t.
static bool	has_crc_error (uint64_t data)
	Checks the CRC8 on a 6-byte payload in this feedback.

Private Attributes
LogonFeedbackCallbacks *	cb_
	Callbacks object.
RailcomHubFlow *	hub_
	The railcom hub we are registered to.

Additional Inherited Members
Static Public Member Functions inherited from FlowInterface< MessageType >
static MessageType *	cast_alloc (QMember *entry)
	Down casts and initializes an asynchronous allocation result to the appropriate flow's buffer type.

Detailed Description

Parser for RailCom feedback that recognizes logon messages.

Definition at line 96 of file LogonFeedback.hxx.

Member Typedef Documentation

PacketType

using dcc::LogonFeedbackParser::PacketType = LogonFeedbackCallbacks::PacketType

Definition at line 99 of file LogonFeedback.hxx.

Member Enumeration Documentation

Errors

enum dcc::LogonFeedbackParser::Errors

private

Enumerator
ERROR_SHIFT	Which bit offset do the error bits start.
ERROR_MASK	Mask where the error bits are.
LENGTH_SHIFT	Which bit offset do the error bits start.
LENGTH_OFFSET	Counts the number of valid 6-bit counts.
LENGTH_MASK	Which bit offset do the error bits start.
PAYLOAD_MASK	Mask where the decoded payload is.
ERROR_MISSING_DATA	Not enough bytes in the feedback response.
ERROR_ACK	Found an ACK byte.
ERROR_OUT_OF_ORDER	Found valid data past an ACK byte or a missing byte.
ERROR_GARBAGE	Found invalid 6/8 code.
ERROR_UNKNOWN	Found unknown codepoint (e.g. NACK or BUSY).

Definition at line 158 of file LogonFeedback.hxx.

Constructor & Destructor Documentation

LogonFeedbackParser()

dcc::LogonFeedbackParser::LogonFeedbackParser ( LogonFeedbackCallbacks *  cb, RailcomHubFlow *  hub  )

inline

Constructor.

Parameters

cb	recognized packets get calls on this object.
hub	the railcom hub for gathering feedback.

Definition at line 103 of file LogonFeedback.hxx.

~LogonFeedbackParser()

dcc::LogonFeedbackParser::~LogonFeedbackParser ( )

inline

Definition at line 110 of file LogonFeedback.hxx.

Member Function Documentation

append_data()

static void dcc::LogonFeedbackParser::append_data ( uint64_t &  data, unsigned &  shift, uint8_t  next_byte  )

inlinestaticprivate

Appends 6 bits of incoming data from railcom.

Parameters

data	the 48-bit aggregated data.
shift	where the next 6 bits should be at (0 to 42)
next_byte	the next byte from the uart.

Definition at line 189 of file LogonFeedback.hxx.

has_crc_error()

static bool dcc::LogonFeedbackParser::has_crc_error ( uint64_t  data )

inlinestaticprivate

Checks the CRC8 on a 6-byte payload in this feedback.

Parameters

data	the feedback bytes (right aligned, first is MSB).

Returns

true if there is a CRC error

Definition at line 259 of file LogonFeedback.hxx.

parse_code()

static uint64_t dcc::LogonFeedbackParser::parse_code ( const Feedback *  fb )

inlinestaticprivate

Parses a concatenated ch1+ch2 response into a single uint64_t.

It contains error flags in the MSB, the number of valid 6-bit codepoints in the second MSB , and 6 bytes data in the LSB, entered with the first wire byte in the third MSB and last wire byte in the LSB.

Any input byte that was missing or contained any other codepoint than a valid 6-bit data codepoint (including garbage or ACK) is translated into zero bits in the parse result.

Parameters

fb	feedback to parse

Returns

parse result.

Definition at line 227 of file LogonFeedback.hxx.

send()

void dcc::LogonFeedbackParser::send ( Buffer< RailcomHubData > *  b, unsigned  priority  )

inlineoverride

Receives railcom feedback.

Definition at line 116 of file LogonFeedback.hxx.

Member Data Documentation

cb_

LogonFeedbackCallbacks* dcc::LogonFeedbackParser::cb_

private

Callbacks object.

Definition at line 271 of file LogonFeedback.hxx.

hub_

RailcomHubFlow* dcc::LogonFeedbackParser::hub_

private

The railcom hub we are registered to.

Definition at line 273 of file LogonFeedback.hxx.

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The documentation for this class was generated from the following file:

• LogonFeedback.hxx