Struct GossipProtocolEngine 

pub struct GossipProtocolEngine { /* private fields */ }

Production-quality gossip dissemination protocol engine.

The engine is not async; it exposes a pure, synchronous API suitable for embedding inside higher-level async event loops. All state is owned by the struct and protected via &mut self.

Implementations

impl GossipProtocolEngine

pub fn new(config: GossipConfig) -> Self

Create a new engine with the given configuration.

The PRNG seed is derived from dedup_cache_size XOR a constant so that default-config engines are reproducible in tests.

pub fn with_defaults() -> Self

Create an engine with default configuration.

pub fn add_peer(&mut self, peer_id: String) -> Result<(), EngineError>

Register a new peer. Returns Ok(()) if the peer was added, or if it was already present (idempotent).

pub fn remove_peer(&mut self, peer_id: &str) -> Result<(), EngineError>

Remove a registered peer. Returns Err(PeerNotFound) if absent.

pub fn create_message( payload: Vec<u8>, topic: String, origin: String, timestamp: u64, max_hops: u8, ) -> Result<GossipMessage, EngineError>

Create a new GossipMessage with a computed FNV-1a ID.

timestamp should be a monotonically-increasing value (e.g. SystemTime::now() milliseconds); when running tests without a real clock, pass any non-zero value.

pub fn receive_message( &mut self, msg: GossipMessage, ) -> Result<Vec<GossipEvent>, EngineError>

Process an incoming GossipMessage.

Returns a Vec<GossipEvent> describing what happened:

• DuplicateDropped if the message was already seen.
• MessageReceived + MessageForwarded if accepted and forwarded.
• MessageReceived only if there are no eligible forward peers.

pub fn select_peers( &mut self, exclude: &str, strategy: &FanoutStrategy, ) -> Vec<String>

Select peers to forward a message to, applying the given strategy.

The returned list excludes exclude (the origin peer) and only contains active peers.

pub fn update_peer_score(&mut self, peer_id: &str, delivered: bool)

Update a peer’s fanout_score using an EMA with α = 0.1.

delivered = true → positive signal (score nudges toward 1.0). delivered = false → negative signal (score nudges toward 0.0).

pub fn pending_messages(&self) -> usize

Number of message IDs currently in the dedup cache.

pub fn stats(&self) -> GossipStats

Return a snapshot of current statistics.

pub fn drain_events(&mut self) -> Vec<GossipEvent>

Drain and return all buffered GossipEvents.

pub fn config(&self) -> &GossipConfig

Borrow the current configuration.

pub fn peer_count(&self) -> usize

Number of registered peers (active + inactive).

pub fn peer(&self, peer_id: &str) -> Option<&GossipPeer>

Get a peer by ID.

pub fn deactivate_peer(&mut self, peer_id: &str) -> Result<(), EngineError>

Mark a peer as inactive without removing it.

pub fn reactivate_peer(&mut self, peer_id: &str) -> Result<(), EngineError>

Reactivate a previously deactivated peer.

pub fn clear_dedup_cache(&mut self)

Reset the dedup cache without touching any other state.