Struct nros_transport_ops_s 

#[repr(C)]
pub struct nros_transport_ops_s {
    pub abi_version: u32,
    pub _reserved: u32,
    pub user_data: *mut c_void,
    pub open: Option<unsafe extern "C" fn(user_data: *mut c_void, params: *const c_void) -> i32>,
    pub close: Option<unsafe extern "C" fn(user_data: *mut c_void)>,
    pub write: Option<unsafe extern "C" fn(user_data: *mut c_void, buf: *const u8, len: usize) -> i32>,
    pub read: Option<unsafe extern "C" fn(user_data: *mut c_void, buf: *mut u8, len: usize, timeout_ms: u32) -> i32>,
}

Runtime-pluggable custom transport. The runtime never dereferences user_data; it’s the caller’s per-transport context, threaded back into every callback’s first argument.

THIS declaration is the ABI single source of truth (RFC-0054): Rust consumes the committed bindgen output of this header, and nros_rmw::NrosTransportOps is the hand-written Rust-side view kept in lockstep with it — not the other way round. The previous wording had that backwards (issue 0331). Layout equivalence is asserted on both sides: see nros_transport_ops_t in nros-rmw-cffi/tests/c_stubs/abi_layout_check.c and the const _ size/align block beside nros_rmw_cffi_set_custom_transport in nros-rmw-cffi/src/lib.rs. Same layout, same threading contract, same return codes.

Fields

abi_version: u32

ABI version. MUST equal NROS_TRANSPORT_OPS_ABI_VERSION_V1. Any other value is rejected at registration time with NROS_RMW_RET_INCOMPATIBLE_ABI.

_reserved: u32

Reserved padding for alignment stability across appends. Set to zero.

user_data: *mut c_void

Opaque caller context, threaded back into every callback. Lifetime: must outlive the transport’s active period (i.e. until close returns).

open: Option<unsafe extern "C" fn(user_data: *mut c_void, params: *const c_void) -> i32>

Open the underlying medium.

@param user_data Caller-supplied context. @param params Opaque per-transport metadata (e.g. UART baud rate, USB-CDC endpoint id). May be NULL. @retval NROS_RMW_RET_OK on success. @retval <0 on failure (any rmw_ret_t error code).

close: Option<unsafe extern "C" fn(user_data: *mut c_void)>

Tear the transport down. After close returns, the runtime will not invoke read or write on this transport unless nros_set_custom_transport is called again.

write: Option<unsafe extern "C" fn(user_data: *mut c_void, buf: *const u8, len: usize) -> i32>

Send len bytes from buf. Must NOT block beyond a brief hardware retry; long blocking should surface as NROS_RMW_RET_TIMEOUT.

@retval NROS_RMW_RET_OK on success. @retval <0 on failure (any rmw_ret_t error code).

read: Option<unsafe extern "C" fn(user_data: *mut c_void, buf: *mut u8, len: usize, timeout_ms: u32) -> i32>

Receive up to len bytes into buf within timeout_ms.

@retval >=0 number of bytes read (may be less than len). @retval <0 on error / timeout (any rmw_ret_t error code).

Trait Implementations

impl Clone for nros_transport_ops_s

fn clone(&self) -> nros_transport_ops_s

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for nros_transport_ops_s

impl Debug for nros_transport_ops_s

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.