Struct QoSProfile 

pub struct QoSProfile {
    pub history: QoSHistoryPolicy,
    pub reliability: QoSReliabilityPolicy,
    pub durability: QoSDurabilityPolicy,
    pub liveliness_kind: QoSLivelinessPolicy,
    pub depth: u32,
    pub deadline_ms: u32,
    pub lifespan_ms: u32,
    pub liveliness_lease_ms: u32,
    pub avoid_ros_namespace_conventions: bool,
    pub tx_express: bool,
}

Full DDS-shaped QoS profile. Matches the field set of upstream rmw_qos_profile_t.

Backends advertise per-policy support via Session::supported_qos_policies; entities created with a profile the active backend can’t honour return TransportError::IncompatibleQos synchronously at create time — no silent downgrade.

Zero-valued time-window fields (“off”) mean infinite — the policy is effectively disabled for the entity.

Fields

history: QoSHistoryPolicy

History policy

reliability: QoSReliabilityPolicy

Reliability policy

durability: QoSDurabilityPolicy

Durability policy

liveliness_kind: QoSLivelinessPolicy

Liveliness policy

depth: u32

History depth (only used if history is KeepLast)

deadline_ms: u32

Subscription max-inter-arrival / publisher offered-rate, ms. 0 = infinite (no deadline check).

lifespan_ms: u32

Sample expiry, ms. Subscribers filter samples older than this. 0 = infinite (no expiry).

liveliness_lease_ms: u32

Liveliness lease, ms. 0 = infinite.

avoid_ros_namespace_conventions: bool

If true, topic-name encoding skips the /rt/ ROS prefix.

tx_express: bool

Phase 282 (#145) — publisher-side “express” hint: this publisher’s samples bypass transport tx batching (zenoh: the wire EXPRESS flag; a batching zenoh-pico session sends them immediately instead of queueing them for the next flush). A transport hint, not a DDS policy — no RxO matching, no backend-compat validation; ignored by subscriptions and by backends without a batching concept.

Implementations

impl QoSProfile

pub fn apply_overrides( self, topic: &str, role: QoSOverrideRole, overrides: &[QoSOverride], ) -> Self

Phase 211.H — fold the plan’s qos_overrides matching topic + role into this profile, returning the overridden profile. Setup-time only (called from create_publisher/create_subscription): a single linear scan over the baked &'static table, no alloc, RT-safe. Later entries win on a duplicate (topic, role, policy) (last-write), matching the planner’s sorted, de-conflicted emit. Non-matching entries are ignored, so passing the whole node table to every entity is cheap + correct.

pub fn apply_override_value(&mut self, value: QoSOverrideValue)

Issue 0303 — apply ONE decoded override value. The single place a policy maps to the field it sets; apply_overrides and the FFI folds both go through it, so a new policy cannot reach some paths only.

pub fn apply_override_codes( self, topic: &str, role: QoSOverrideRole, codes: &[QoSOverrideCode], ) -> Self

Issue 0303 — fold baked QoSOverrideCodes for one (topic, role). Unrecognised codes are skipped; the producers reject them at BAKE time (nros_orchestration_ir::qos_override), so a code reaching here that this build does not know is an older image running newer data, not a user error to diagnose at runtime.

impl QoSProfile

pub const BEST_EFFORT: Self

Best-effort QoS (for real-time)

pub const RELIABLE: Self

Reliable QoS

pub const QOS_PROFILE_SYSTEM_DEFAULT: Self

rmw_qos_profile_system_default — an absence, not a profile.

issue 0829. Every field is the sentinel: upstream’s constant names no concrete policy at all, and the two reference RMWs fill the absence with different numbers — rmw_cyclonedds_cpp’s create_readwrite_qos folds RMW_QOS_POLICY_DEPTH_SYSTEM_DEFAULT to KEEP_LAST(1), while rmw_zenoh_cpp’s QoS::QoS() fills it from RMW_ZENOH_DEFAULT_HISTORY_DEPTH, which is 42, over a comment stating the contract outright: “If the depth field in the qos profile is set to 0, the RMW implementation has the liberty to assign a default depth.”

So no baked number can be right. This carried a concrete Reliable / Volatile / KeepLast(1) until 2026-09-03, and nros::qos::SYSTEM_DEFAULT carried a concrete depth 10, which is how one name shipped two queue depths. Both are gone; the backend resolves this at its create entry via QoSProfile::resolve_system_default.

liveliness_kind is QoSLivelinessPolicy::None, which IS the sentinel on that policy — it lowers to NROS_RMW_LIVELINESS_SYSTEM_DEFAULT (0), the two having collapsed onto one value in phase-376 W5/B2.

pub const QOS_PROFILE_DEFAULT: Self

Default QoS profile (matches rmw_qos_profile_default)

pub const QOS_PROFILE_SENSOR_DATA: Self

Sensor data QoS profile (matches rmw_qos_profile_sensor_data)

pub const QOS_PROFILE_SERVICES_DEFAULT: Self

Services default QoS profile (matches rmw_qos_profile_services_default)

pub const QOS_PROFILE_PARAMETERS: Self

Parameters QoS profile (matches rmw_qos_profile_parameters) Mirrors rmw_qos_profile_parameters: KEEP_LAST(1000), RELIABLE, VOLATILE.

issue 0793 — this said TransientLocal until 2026-08-25, disagreeing both with upstream (/opt/ros/<distro>/include/rmw/rmw/qos_profiles.h) and with our own second copy of the same profile, nros::qos::PARAMETERS, which was already correct. Two copies of one profile that disagree is the defect; the wrong one being the one named after the upstream constant is what made it hard to see.

pub const QOS_PROFILE_CLOCK: Self

Clock QoS profile - same as sensor data but with depth 1

pub const QOS_PROFILE_PARAMETER_EVENTS: Self

Parameter events QoS profile (matches rmw_qos_profile_parameter_events)

pub const QOS_PROFILE_ACTION_STATUS_DEFAULT: Self

Action status default QoS profile (matches rcl_action_qos_profile_status_default)

pub const QOS_PROFILE_PX4: Self

PX4 companion QoS profile (Phase 233 / RFC-0039 Track B). Matches the QoS PX4’s uxrce_dds_client uses on /fmu/out/* and /fmu/in/* — BEST_EFFORT + VOLATILE + KEEP_LAST(1). A nano-ros node talking to the same MicroXRCEAgent must use this (a reliable or TRANSIENT_LOCAL reader will not match PX4’s volatile best-effort writers). Verified against real PX4 SITL (nros-px4-sitl-test): TRANSIENT_LOCAL durability silently fails to match /fmu/out/*. Adjust depth via .keep_last(n) for higher-rate streams.

pub const fn new() -> Self

Create new QoS settings with defaults (matches QOS_PROFILE_DEFAULT: Reliable, Volatile, KeepLast(10)).

pub const fn topics_default() -> Self

Get the default QoS profile for ordinary topics

pub const fn px4() -> Self

The PX4 companion QoS profile (QOS_PROFILE_PX4) — use for /fmu/out/* subscriptions and /fmu/in/* publications against a MicroXRCEAgent.

pub const fn sensor_data_default() -> Self

Get the default QoS profile for sensor data topics

pub const fn services_default() -> Self

Get the default QoS profile for services

pub const fn parameters_default() -> Self

Get the default QoS profile for parameter services

pub const fn parameter_events_default() -> Self

Get the default QoS profile for parameter events

pub const fn system_default() -> Self

Get the system default QoS profile

pub const fn action_status_default() -> Self

Get the default QoS profile for action status topics

pub const fn clock_default() -> Self

Get the default QoS profile for clock topics

pub const fn keep_last(self, depth: u32) -> Self

Set history to keep last N messages

pub const fn keep_all(self) -> Self

Set history to keep all messages

pub const fn reliable(self) -> Self

Set reliability to reliable

pub const fn best_effort(self) -> Self

Set reliability to best-effort

pub const fn volatile(self) -> Self

Set durability to volatile

pub const fn transient_local(self) -> Self

Set durability to transient local

pub const fn reliability(self, policy: QoSReliabilityPolicy) -> Self

Set reliability policy explicitly

pub const fn durability(self, policy: QoSDurabilityPolicy) -> Self

Set durability policy explicitly

pub const fn history(self, policy: QoSHistoryPolicy) -> Self

Set history policy explicitly

pub const fn depth(self, depth: u32) -> Self

Set history depth explicitly

pub const fn tx_express(self, express: bool) -> Self

Phase 282 (#145) — mark this publisher’s samples “express”: they bypass transport tx batching (sent immediately even when the batching knob is on). A transport hint for control-tier / latency-sensitive topics; ignored on subscriptions and by backends without batching.

pub const fn history_depth(&self) -> u8

Get history depth (for backwards compatibility)

impl QoSProfile

pub fn required_policies(&self) -> QoSPolicyMask

Compute the set of QoS policies actually requested by this profile.

Zero-valued time fields and LivelinessKind::None count as “not requesting” the corresponding policy — the cheap default.

issue 0829 — the four CORE bits (reliability, durability, history, depth) used to be added UNCONDITIONALLY, on the reasoning that every nano-ros backend honours them. That is true and still not the right test: this function answers what did the caller ASK FOR, and a SYSTEM_DEFAULT policy asks for nothing. Starting from CORE made QOS_PROFILE_SYSTEM_DEFAULT demand all four, so a backend that could not honour one would reject the profile with IncompatibleQos — for requesting nothing. The pattern was already here for the extended policies three lines down (a zero deadline_ms declines its bit); it just never reached the four CORE ones.

This RELAXES the mask, so it can only turn a rejection into an acceptance, never the reverse — and it flips no verdict today: every supported_qos_policies impl in the tree returns at least CORE (traits.rs default impl, nros-node/src/mock.rs:259, nros-rmw-cffi/src/lib.rs:2580, nros-rmw-zenoh/src/shim/session.rs:1245), so a CORE bit has never been the reason for a failure.

pub fn validate_against( &self, supported: QoSPolicyMask, ) -> Result<(), TransportError>

Returns Err(TransportError::IncompatibleQos) if any policy this profile requires is missing from the backend’s supported mask. Used at entity-create time to enforce the no silent degradation contract.

pub const fn resolve_system_default(self, defaults: &QoSSystemDefaults) -> Self

Replace every SYSTEM_DEFAULT field with the backend’s own answer.

issue 0829 — a backend calls this at its create entry, before anything is derived from the profile (see QoSSystemDefaults for why the ordering matters on the zenoh path). Fields the caller DID state are left exactly as they are: this resolves an absence, it never overrides a request.

Idempotent, and safe to call on a fully concrete profile — a profile with no sentinel in it is returned unchanged.

pub const fn has_unresolved_system_default(&self) -> bool

true if any field is still the SYSTEM_DEFAULT sentinel.

Depth is deliberately NOT part of this test: a KEEP_ALL profile legitimately carries depth 0 forever (QOS_PROFILE_PARAMETER_EVENTS), and a backend that resolves the sentinel depth to 0 — XRCE does, on purpose — leaves a resolved profile reading 0 here. This asks about the three POLICY fields, where the sentinel is a distinct variant and so cannot be confused with a stated value.

Trait Implementations

impl Clone for QoSProfile

fn clone(&self) -> QoSProfile

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for QoSProfile

impl Debug for QoSProfile

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

Formats the value using the given formatter.

impl Default for QoSProfile

fn default() -> Self

Returns the “default value” for a type.

impl Eq for QoSProfile

impl PartialEq for QoSProfile

fn eq(&self, other: &QoSProfile) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for QoSProfile