Struct Pacemaker

pub(crate) struct Pacemaker<N: Network> {
    config: PacemakerConfiguration,
    state: PacemakerState,
    view_info: ViewInfo,
    sender: SenderHandle<N>,
    event_publisher: Option<Sender<Event>>,
}

A single participant in the Pacemaker subprotocol.

Usage

After creating an instance of the Pacemaker struct using new, the caller interacts with it by calling three methods:

After creating an instance of Pacemaker using new, the caller should interact with it by calling three methods:

1. on_receive_msg: this method should be called whenever a PacemakerMessage is received satisfying the method’s preconditions.
2. tick: this method should be called as often as is practical.
3. query: whenever on_receive_msg or tick is called, the internal view counter of the Pacemaker may be updated. The caller should call query whenever it needs to see this counter.

Fields

config: PacemakerConfiguration

state: PacemakerState

view_info: ViewInfo

sender: SenderHandle<N>

event_publisher: Option<Sender<Event>>

Implementations

impl<N: Network> Pacemaker<N>

pub(crate) fn new( config: PacemakerConfiguration, sender: SenderHandle<N>, init_view: ViewNumber, init_validator_set_state: &ValidatorSetState, event_publisher: Option<Sender<Event>>, ) -> Result<Self, PacemakerError>

Create a new Pacemaker instance..

pub(crate) fn query(&self) -> &ViewInfo

Query the Pacemaker for its current ViewInfo.

pub(crate) fn tick<K: KVStore>( &mut self, block_tree: &BlockTreeSingleton<K>, ) -> Result<(), PacemakerError>

Cause the Pacemaker to check the current time (“clock tick”), possibly updating its internal state or causing it to send messages to other replicas.

pub(crate) fn on_receive_msg<K: KVStore>( &mut self, msg: PacemakerMessage, origin: &VerifyingKey, block_tree: &mut BlockTreeSingleton<K>, ) -> Result<(), PacemakerError>

Execute the required steps in the Pacemaker subprotocol upon receiving a PacemakerMessage from the replica identified by origin.

Precondition

msg.view() must be greater than or equal to the current view.

fn on_receive_timeout_vote<K: KVStore>( &mut self, timeout_vote: TimeoutVote, origin: &VerifyingKey, block_tree: &mut BlockTreeSingleton<K>, ) -> Result<(), PacemakerError>

Execute the required steps in the Pacemaker subprotocol upon receiving a TimeoutVote message from the replica identified by origin.

Precondition

timeout_vote.view >= self.query().view

fn on_receive_advance_view<K: KVStore>( &mut self, advance_view: AdvanceView, origin: &VerifyingKey, block_tree: &mut BlockTreeSingleton<K>, ) -> Result<(), PacemakerError>

Execute the required steps in the Pacemaker protocol upon receiving an AdvanceView message.

Preconditions

advance_view.progress_certificate.view() >= self.query().view

fn update_view( &mut self, next_view: ViewNumber, validator_set_state: &ValidatorSetState, ) -> Result<(), PacemakerError>

Update the Pacemaker’s state in order to enter a specified next_view.

Preconditions

This function should only be called if next_view is greater than the current view. Otherwise, an UpdateViewError will be returned.

fn extend_view(&mut self) -> Result<(), ExtendViewError>

Extend the timeout of the current view, which must be an Epoch-Change View.

Errors

This function should only be called if the current view is an Epoch-Change View. Otherwise, an ExtendViewError will be returned.