Protocols

constellation::protocol Namespace

enum class constellation::protocol::Protocol : std::uint8_t

Protocol Enum (excluding CHIRP)

Values:

enumerator CSCP1

Constellation Satellite Control Protocol v1

enumerator CMDP1

Constellation Monitoring Distribution Protocol v1

enumerator CDTP1

Constellation Data Transmission Protocol v1

enumerator CHP1

Constellation Heartbeat Protocol v1

std::string_view constellation::protocol::get_protocol_identifier(Protocol protocol)

Get protocol identifier string for CSCP, CMDP and CDTP protocols

Parameters:

protocol – Protocol

Returns:

Protocol identifier string in message header

Protocol constellation::protocol::get_protocol(std::string_view protocol_identifier)

Get protocol from a protocol identifier string

Parameters:

protocol_identifier – Protocol identifier string

Returns:

Protocol

inline std::string constellation::protocol::get_readable_protocol(std::string_view protocol_identifier)

Get human-readable protocol identifier string for CSCP, CMDP and CDTP protocols

Parameters:

protocol_identifier – Protocol identifier string

Returns:

Protocol identifier string with byte version replaced to human-readable version

inline std::string constellation::protocol::get_readable_protocol(Protocol protocol)

Get human-readable protocol identifier string for CSCP, CMDP and CDTP protocols

Parameters:

protocol – Protocol

Returns:

Protocol identifier string with byte version replaced to human-readable version

constellation::protocol::CSCP Namespace

enum class constellation::protocol::CSCP::State : std::uint8_t

Possible Satellite FSM states

The following statements can be made about states:

• States with lower four bits equal to zero are steady states, e.g. INIT.

• The other states are transition, and their lower four bits indicate the steady state the enter into, e.g. the lower four bits of state landing are 0x2, so this transitional state enters into steady state 0x20, INIT.

Values:

enumerator NEW

enumerator initializing

enumerator INIT

enumerator launching

enumerator ORBIT

enumerator landing

enumerator reconfiguring

enumerator starting

enumerator RUN

enumerator stopping

enumerator interrupting

enumerator SAFE

enumerator ERROR

enum class constellation::protocol::CSCP::Transition : std::uint8_t

Possible FSM transitions

Values:

enumerator initialize

enumerator initialized

enumerator launch

enumerator launched

enumerator land

enumerator landed

enumerator reconfigure

enumerator reconfigured

enumerator start

enumerator started

enumerator stop

enumerator stopped

enumerator interrupt

enumerator interrupted

enumerator failure

enum class constellation::protocol::CSCP::TransitionCommand : std::underlying_type_t<Transition>

Possible transition commands via CSCP

Values:

enumerator initialize

enumerator launch

enumerator land

enumerator reconfigure

enumerator start

enumerator stop

enumerator _interrupt

enumerator _failure

enum class constellation::protocol::CSCP::StandardCommand : std::underlying_type_t<TransitionCommand>

Possible standard (non-transition) commands via CSCP

Values:

enumerator get_name

enumerator get_version

enumerator get_commands

enumerator get_state

enumerator get_role

enumerator get_status

enumerator get_config

enumerator get_run_id

enumerator shutdown

enumerator _get_commands

enumerator _get_remotes

enumerator _get_services

bool constellation::protocol::CSCP::is_steady(State state)

Check if a state is steady.

bool constellation::protocol::CSCP::is_shutdown_allowed(State state)

Check if the CSCP shutdown command is allowed from a given state.

Shutdown is only allowed from NEW, INIT, SAFE and ERROR.

bool constellation::protocol::CSCP::transitions_from(State transition, State steady)

Check if “transition” is a transitional state from steady state “steady” to a new steady state.

bool constellation::protocol::CSCP::transitions_to(State transition, State steady)

Check if “transition” is a transitional state from a former state into steady state “steady”.

template<State... states>
bool constellation::protocol::CSCP::is_one_of_states(State state)

Check if given state is in one of template states list.

Parameters:

state – State to check

Returns:

True if state equals one of the states given in the template parameters

template<State... states>
static bool constellation::protocol::CSCP::is_not_one_of_states(State state)

Check if given state is not in one of template states list.

Parameters:

state – State to check

Returns:

True if state equals none of the states given in the template parameters

inline bool constellation::protocol::CSCP::is_valid_satellite_name(const std::string &satellite_name)

Checks if a satellite name is valid.

A satellite name may contain alphanumeric characters and underscores and may not be empty.

inline bool constellation::protocol::CSCP::is_valid_canonical_name(const std::string &canonical_name)

Checks if a canonical name is valid.

A canonical name consists of two parts, separated by a period. Both parts may contain alphanumeric characters and underscores and may not be empty.

inline bool constellation::protocol::CSCP::is_valid_run_id(const std::string &run_id)

Checks if a run ID is valid.

A run ID may contain alphanumeric characters, underscores or dashes and may not be empty.

inline bool constellation::protocol::CSCP::is_valid_command_name(const std::string &command_name)

Checks if a command name is valid.

A command may contain alphanumeric characters or underscores, and may not be empty or start with a digit.

constellation::protocol::CHP Namespace

enum constellation::protocol::CHP::MessageFlags

Possible CHP message flags

Values:

enumerator NONE

enumerator DENY_DEPARTURE

Indicating that the sender should not be allowed to depart, and an interrupt should be triggered

enumerator TRIGGER_INTERRUPT

Indicating that ERROR or SAFE states and missing heartbeats should trigger an interrupt

enumerator MARK_DEGRADED

Indicating that the current run should me marked as degraded if this sender reports failure or disappears

enumerator IS_EXTRASYSTOLE

enum class constellation::protocol::CHP::Role : std::uint8_t

Satellite roles, representing a combination of message flags

Values:

enumerator NONE

No Flags.

enumerator TRANSIENT

Flags MARK_DEGRADED.

enumerator DYNAMIC

Flags MARK_DEGRADED, TRIGGER_INTERRUPT.

enumerator ESSENTIAL

Flags MARK_DEGRADED, TRIGGER_INTERRUPT, DENY_DEPARTURE.

static std::uint8_t constellation::protocol::CHP::Lives = 3

Default lives for a remote on detection/replenishment

static std::chrono::milliseconds constellation::protocol::CHP::MinimumInterval = std::chrono::milliseconds(500)

Minimal interval between heartbeat messages

static std::chrono::milliseconds constellation::protocol::CHP::MaximumInterval = std::chrono::milliseconds(300000)

Default maximum interval between heartbeat messages

static double constellation::protocol::CHP::LoadFactor = 3.

Load factor to scale CHP subscriber weight in interval scaling

MessageFlags constellation::protocol::CHP::flags_from_role(Role role)

Get flags for a given role.

Parameters:

role – Role

Role constellation::protocol::CHP::role_from_flags(MessageFlags flags)

Get role from given message flags.

Parameters:

flags – Message flags

bool constellation::protocol::CHP::role_requires(Role role, MessageFlags flags)

Check if the given role requires the given message flag.

Parameters:

• role – Role

• flags – Message flags

Returns:

True if role mandates the flag, false otherwise

std::chrono::milliseconds constellation::protocol::CHP::calculate_interval(std::size_t subscribers, std::chrono::milliseconds max)

Method to calculate the heartbeat interval based on the number of subscriber satellites and a maximum interval Using a load factor to scale down number of messages.

Parameters:

• subscribers – Current number of subscriber satellites

• max – Maximum allowed interval between heartbeats

Returns:

New heartbeat interval