zerodds-discovery

DDSI-RTPS discovery for ZeroDDS. Layer 2 (wire implementation).

Pure-Rust no_std + alloc, forbid(unsafe_code), safety class SAFE.

Spec

• DDSI-RTPS 2.5 §8.5.3 — Simple Participant Discovery (SPDP).
• DDSI-RTPS 2.5 §8.5.4 — Simple Endpoint Discovery (SEDP).
• XTypes 1.3 §7.6.3.3.4 — TypeLookup service (4 builtin endpoints, service-instance-name).
• DDS-Security 1.2 §7.4.4 + §7.4.5 — Stateless + Volatile-Secure builtin-endpoint slots.

Coverage-Doc: docs/spec-coverage/ddsi-rtps-2.5.md.

What this crate provides

SPDP (spdp module)

• SpdpBeacon — beacon sender (DATA datagram with ParticipantBuiltinTopicData).
• SpdpReader — beacon-receiver parser.
• DiscoveredParticipantsCache — discovered-participants set with last_seen lease tracking.

SEDP (sedp module)

• SedpStack — integrated SEDP state machine (participant lifecycle → SEDP proxy wiring).
• SedpPublicationsWriter / SedpPublicationsReader — reliable pub/sub discovery.
• SedpSubscriptionsWriter / SedpSubscriptionsReader — reliable sub discovery.
• DiscoveredEndpointsCache — discovered-endpoints set.

TypeLookup (type_lookup module)

• TypeLookupServer — server-side handler with pagination.
• TypeLookupClient — client-side correlation table with a pending-request cap.
• TypeLookupEndpoints — 4 builtin-endpoint GUIDs + service-instance-name formatter.

Security (security module)

• SecurityBuiltinStack — DDS-Security Stateless + Volatile-Secure endpoints (BuiltinEndpointSet bits 22..25).

Match logic (endpoint_match module)

• Topic identity + type compatibility (TypeMatcher) + QoS compatibility.

Layer boundary toward DCPS

Discovery provides the wire-format primitives. Instantiating the reliable writer/reader pairs on the builtin-endpoint GUIDs is the responsibility of the DCPS layer (crates/dcps/src/runtime.rs):

Tests

cargo test -p zerodds-discovery

144+ tests green (lib + integration). Live-interop tests against Cyclone DDS available via --features live-interop.

License

Apache-2.0 OR MIT — see workspace root.