Struct CffiPublisher 

pub struct CffiPublisher { /* private fields */ }

Publisher backed by a C vtable.

Implementations

impl CffiPublisher

pub fn topic_name(&self) -> &str

Topic name. Result is the null-terminated string written at publisher creation; never re-resolved from the backend.

pub fn type_name(&self) -> &str

Fully-qualified type name ("std_msgs/msg/Int32").

pub fn qos(&self) -> NrosRmwQos

QoS used to create this publisher.

pub fn can_loan_messages(&self) -> bool

true iff the backend exposes the publish loan primitive (Phase 99). Mirrors upstream rmw_publisher_t::can_loan_messages.

Trait Implementations

impl Drop for CffiPublisher

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl Publisher for CffiPublisher

fn actual_qos(&self) -> QoSProfile

The profile the backend GRANTED, read back at create time.

Answers off the retained value rather than re-entering the backend: upstream’s rmw_publisher_get_actual_qos is a property of the entity, and a backend call here would make an accessor a transport operation on a &self that any callback may hold.

fn get_gid(&self) -> Result<[u8; 24], TransportError>

Upstream rmw_get_gid_for_publisher, through the vtable slot.

The phase-467 RMW gap-closure design study’s Q1, step 2. A NULL slot answers Unsupported — uORB and XRCE NULL it. The Rust adapter table zenoh rides FILLS it now (it was NULL there too until this study, so a Rust backend with a real identity could not report one). Never an all-zero gid: that is what the uninitialised rmw_gid_t below holds, so returning it on the NULL path would make “no identity” read exactly like an answer.

The backend’s implementation_identifier is deliberately DROPPED here. nros_rmw_cffi_register_named admits several backends in one image and gids from two of them are not comparable, so upstream’s pairing matters — but the trait answers bytes, and the identifier a caller needs is the one on the SESSION it asked. Carrying a second copy per publisher would be a second place for it to disagree.

fn count_matched_subscriptions(&self) -> Result<usize, TransportError>

Upstream rmw_publisher_count_matched_subscriptions, through the vtable slot. Issue 1643 — the slot’s first RUNTIME reader (the node API’s get_subscription_count); until then only an interop probe and the backend’s own tests asked. A NULL slot answers Unsupported.

type Error = TransportError

Error type for publish operations

fn publish_raw(&self, data: &[u8]) -> Result<(), TransportError>

Publish a CDR-serialised message.

unsafe fn publish_streamed( &self, size_cb: unsafe extern "C" fn(out_total_len: *mut usize, user_ctx: *mut c_void), chunk_cb: unsafe extern "C" fn(out_buf: *mut u8, cap: usize, out_written: *mut usize, user_ctx: *mut c_void), user_ctx: *mut c_void, ) -> Result<(), TransportError>

Phase 124.E.1 — streamed publish.

fn buffer_error(&self) -> TransportError

Return a buffer-too-small error (implementation specific)

fn serialization_error(&self) -> TransportError

Return a serialization error (implementation specific)

fn unsupported_event_error(&self) -> TransportError

Phase 108 — backend’s error variant for “this event kind is not supported.” Default impl reuses serialization_error() since most backends share an Unsupported variant; backends override if they have a distinct Unsupported mapping.

unsafe fn register_event_callback( &mut self, kind: EventKind, deadline_ms: u32, cb: EventCallback, user_ctx: *mut c_void, ) -> Result<(), TransportError>

Phase 108 — register a callback fired when the named status event occurs. deadline_ms applies to EventKind::OfferedDeadlineMissed only; ignored otherwise. Default impl returns the backend’s “unsupported”-shaped error.

fn supports_event(&self, kind: EventKind) -> bool

Phase 108 — true if the backend can generate this event for this publisher. Default returns false; backends override per supported event kind.

fn assert_liveliness(&self) -> Result<(), TransportError>

Phase 109 — assert this publisher’s liveliness manually. Required for publishers configured with QoSLivelinessPolicy::ManualByTopic / ManualByNode; nothing to do for the other kinds.

fn publish_raw_with_attachment( &self, data: &[u8], _attachment: &[u8], ) -> Result<(), Self::Error>

Phase 128.F.4 — publish with an opaque attachment block.

fn publish<M>(&self, msg: &M, buf: &mut [u8]) -> Result<(), Self::Error>

where M: RosMessage,

Publish a typed message (serializes automatically)