Struct rmw_message_info_t 

#[repr(C)]
pub struct rmw_message_info_t {
    pub source_timestamp: rmw_time_point_value_t,
    pub received_timestamp: rmw_time_point_value_t,
    pub publication_sequence_number: u64,
    pub reception_sequence_number: u64,
    pub publisher_gid: rmw_gid_t,
    pub from_intra_process: bool,
}

Per-sample metadata — upstream rmw_message_info_t, field for field.

Phase 376 W4. Today this metadata reaches Rust callers through MESSAGE_INFO_TABLE, a side table in nros-rmw-cffi keyed on the subscription’s backend_data ADDRESS. That table is a workaround, not a design, and it never crosses the seam it exists for: only the Rust trampoline writes it, so a C or C++ backend has no symbol to call and message info is permanently absent for them. It also claims a pool slot per subscription and never releases it, so a reused handle address inherits the previous subscription’s metadata.

Passing the struct by pointer on the take call — which is what upstream does — removes all of that: the caller owns the storage, it lives exactly as long as the call, and every backend can fill it.

Retiring the side table is NOT part of this change; the take_with_info slots are the mechanism that makes retiring it possible.

Fields

source_timestamp: rmw_time_point_value_t

Publisher’s clock at publication, ns. 0 = no source timestamp.

received_timestamp: rmw_time_point_value_t

Subscriber’s clock at reception, ns. 0 = receptions are not stamped.

publication_sequence_number: u64

Publisher-side sequence, or RMW_MESSAGE_INFO_SEQUENCE_NUMBER_UNSUPPORTED. Whether this is real is what feature_supported answers.

reception_sequence_number: u64

Subscriber-side reception count, or the same sentinel.

publisher_gid: rmw_gid_t

Which publisher sent it. All-zero data = unknown.

from_intra_process: bool

True when the sample never left the image (Zephyr’s Z_FEATURE_LOCAL_SUBSCRIBER, DDS intra-process).

Trait Implementations

impl Clone for rmw_message_info_t

fn clone(&self) -> rmw_message_info_t

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for rmw_message_info_t

impl Debug for rmw_message_info_t

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

Formats the value using the given formatter.