Crate nros_rmw_cffi 

C function table adapter for nros RMW backends.

This crate provides a vtable-based bridge so that backends written in C, C++, Zig, Ada, or any language with a C-compatible ABI can implement the nros Session / Publisher / Subscription / service traits without writing Rust code.

Usage (C backend implementor)

1. Include <nros/rmw_vtable.h>
2. Implement all function pointers in nros_rmw_vtable_t
3. Call nros_rmw_cffi_register(&my_vtable) before creating sessions

Usage (Rust consumer)

Enable the rmw-cffi feature on nros and use Executor<CffiSession>.

Re-exports

pub use rust_adapter::RustBackend;

pub use rust_adapter::RustBackendAdapter;

pub use generated::*;

Modules

generated

AUTO-GENERATED by scripts/gen-abi-bindings.sh (bindgen 0.72.1) — DO NOT EDIT.

rust_adapter

Phase 115.L.0 — Generic Rust-trait → C-vtable adapter.

section

RMW backend self-registration (Phase 249 P4b.1 — .init_array ctor).

Macros

nros_rmw_register_backend

Macro emitted by backend crates to self-register their vtable.

Structs

CffiClient

Service client backed by a C vtable.

CffiPublisher

Publisher backed by a C vtable.

CffiRmw

RMW factory for the C function table backend.

CffiService

Service server backed by a C vtable.

CffiSession

Session backed by a C vtable.

CffiSubscription

Subscription backed by a C vtable.

Enums

BackendResolution

Phase 128.A.3 — outcome of resolve_backend.

Constants

EMPTY_VTABLE

A vtable with every slot NULL — the base for struct-update syntax.

MAX_BACKENDS

Compile-time max number of concurrently registered backends. Set via NROS_RMW_MAX_BACKENDS env var at build time (build.rs). Default 8.

MAX_NODES

Distinct (session, name, namespace) triples the shim tracks. Raise with NROS_RMW_MAX_NODES; the default mirrors the executor’s MAX_NODES.

NROS_RMW_QOS_PROFILE_DEFAULT

Standard rmw_qos_profile_default-equivalent.

NROS_RMW_QOS_PROFILE_PARAMETERS

Standard rmw_qos_profile_parameters-equivalent.

NROS_RMW_QOS_PROFILE_SENSOR_DATA

Standard rmw_qos_profile_sensor_data-equivalent.

NROS_RMW_QOS_PROFILE_SERVICES_DEFAULT

Standard rmw_qos_profile_services_default-equivalent.

NROS_RMW_QOS_PROFILE_SYSTEM_DEFAULT

Standard rmw_qos_profile_system_default-equivalent — all sentinel.

Functions

backend_registered

Phase 104.A — registry-presence probe. Returns true iff at least one backend is registered. Used by Executor::open to detect “user forgot to register a backend before opening the session” and fail with a meaningful error.

backend_resolution_to_ret

Phase 128.A.3 — map a BackendResolution to its canonical NrosRmwRet. BackendResolution::Single is not an error and returns NROS_RMW_RET_OK; callers needing the vtable should pattern-match on the resolution itself.

error_from_ret

Map a rmw_ret_t returned by a C-side vtable function back to a TransportError for the Rust caller. Inverse of ret_from_error — used when nros-rmw-cffi’s CffiSession etc. receive a code from the registered C backend.

event_kind_from_c

Convert a C ABI event-kind discriminant to the trait-level nros_rmw::EventKind. Replaces the retired From<NrosRmwEventKind> for nros_rmw::EventKind. Unknown values map to MessageLost, mirroring the forward direction’s fallback.

event_kind_to_c

Convert a trait-level nros_rmw::EventKind to the C ABI discriminant. Replaces the retired From<nros_rmw::EventKind> for NrosRmwEventKind.

nros_rmw_cffi_lookup^⚠

Look up a backend’s vtable by name. Returns NULL if no backend is registered under name.

nros_rmw_cffi_register^⚠Deprecated

Register a custom RMW backend vtable (legacy single-arg form).

nros_rmw_cffi_register_named^⚠

Register a backend under a stable name. Multiple backends can coexist; consumers select via nros_rmw_cffi_lookup or the higher-level Executor::node_builder(...).rmw(...) path.

nros_rmw_cffi_registered_names^⚠

Diagnostic helper — fills buf with pointers to up to cap registered backend names. Returns the number of names available (may exceed cap). Pointer-valid for the program’s lifetime.

nros_rmw_cffi_set_custom_transport^⚠

Phase 115.A.2 — C entry point for installing a custom transport.

nros_rmw_qos_incompatibility_mask^⚠

See nros/rmw_entity.h.

resolve_backend

Phase 128.A.3 — selection policy for the single-backend Executor::open / nros::init path.

ret_from_error

Map a TransportError to the corresponding rmw_ret_t code.

rmw_compare_gids_equal^⚠

See nros/rmw_entity.h.

rmw_qos_profile_check_compatible^⚠

See nros/rmw_entity.h.

rmw_severity_of

Map nros_log’s ladder onto upstream’s.

set_backend_log_severity

Set the verbosity of every registered BACKEND’s own logging.

Type Aliases

NrosRmwClient

Compat alias for the generated rmw_client_t.

NrosRmwCountStatus

Compat alias for the generated rmw_count_status_t.

NrosRmwEventCallback

Compat alias for the generated rmw_status_event_callback_t (nullable — Option-wrapped fn pointer, per C ABI).

NrosRmwEventKind

Compat alias for the generated rmw_event_type_t::Type (C-unsigned-sized event-kind discriminant).

NrosRmwEventPayload

Compat alias for the generated rmw_event_payload_t union.

NrosRmwLivelinessChangedStatus

Compat alias for the generated rmw_liveliness_changed_status_t.

NrosRmwNode

Phase 376 W5/B1 — a graph node. The first argument of the four create_* slots, in place of the fabricated per-call session view they used to take.

NrosRmwPublisher

Compat alias for the generated rmw_publisher_t.

NrosRmwQos

Compat alias for the generated rmw_qos_profile_t.

NrosRmwRet

Compat alias for the generated rmw_ret_t typedef. Zero on success; negative on error.

NrosRmwService

Compat alias for the generated rmw_service_t.

NrosRmwSession

Compat alias for the generated rmw_session_t.

NrosRmwSessionOptions

issue 0808 — session creation options; NULL means every default.

NrosRmwSubscription

Compat alias for the generated rmw_subscription_t.

NrosRmwVtable

Compat alias for the generated nros_rmw_vtable_t.