Module engine 

The PexEngine — the transport-agnostic, sans-IO core both a DIG Node and the relay embed (SPEC Appendix A).

You feed the engine four kinds of input and it returns the messages to send + the events to act on; it does no I/O itself (the node/relay do the actual dig-nat mux / WebSocket reads and writes):

• link events — link_up (produces our outgoing handshake + snapshot) and link_down (discards all per-link state, SPEC §5.5);
• inbound messages — on_message validates + advances the receiver state machine, returning verified-candidate / dropped events and any pex_error replies, and penalizing misbehavior (SPEC §5, §6.4, §7, §11);
• local peer-set changes — upsert_known / remove_known maintain the first-hand set PEX advertises (SPEC §9.3);
• clock ticks — tick (~1/s) emits per-link pex_deltas for pending changes, spaced by the effective interval (SPEC §6).

Timestamps are Unix epoch milliseconds. See crate docs for the node vs relay embedding.

Structs

PexConfig

Configuration for a PexEngine (SPEC Appendix A).

PexEngine

The transport-agnostic PEX engine (SPEC Appendix A). One instance per participant; it multiplexes all of that participant’s links.

PexOutcome

The result of feeding the engine an inbound message or transport error: the messages to send back on the link, plus the events for the host to act on.

Enums

PexEvent

An event the engine surfaces from an inbound message for the host to act on (SPEC Appendix A).