Crate nros_node 

Node abstraction for nros

This crate provides the high-level Node API for creating ROS 2 compatible publishers and subscribers on embedded systems.

Executor-Based API

The executor-based API provides a unified interface that works on both std (desktop) and no_std (embedded) targets.

Desktop Example

use nros::prelude::*;
use std_msgs::msg::Int32;

let config = ExecutorConfig::from_env().node_name("my_node");
let mut executor: Executor = Executor::open(&config)?;

// Register subscription callback
let node = executor.node_builder("my_node").build()?;
executor.node_mut(node).create_subscription::<Int32, _>("/topic", |msg: &Int32| {
    println!("Received: {}", msg.data);
})?;

// Spin (processes callbacks)
executor.spin_blocking(SpinOptions::default());

Embedded Example

use nros::prelude::*;
use std_msgs::msg::Int32;

let config = ExecutorConfig { locator: "tcp/192.168.1.1:7447", ..Default::default() };
let mut executor: Executor = Executor::open(&config)?;

// Register subscription callback
let node = executor.node_builder("my_node").build()?;
executor.node_mut(node).create_subscription::<Int32, _>("/cmd", |msg: &Int32| {
    // process message...
})?;

// In your main loop:
loop {
    executor.spin_once(core::time::Duration::from_millis(10));
    // platform delay...
}

Features

• std - Enable standard library support (spin_blocking)
• alloc - Enable heap allocation (parameter service boxed replies)

Re-exports

pub use timer::TimerCallbackFn;

pub use timer::TimerDuration;

pub use timer::TimerHandle;

pub use timer::TimerMode;

pub use timer::TimerState;

pub use lifecycle::LifecycleCallbackFn;

pub use lifecycle::LifecycleError;

pub use lifecycle::LifecyclePollingNode;

pub use executor::BootConfig;

pub use executor::BootConfigError;

pub use executor::DOMAIN_ID_EXPLICIT_ZERO_C_ABI;

pub use executor::DOMAIN_ID_MAX;

pub use executor::EnvRung;

pub use executor::ExecutorConfig;

pub use executor::ExecutorSemantics;

pub use executor::GuardCondition;

pub use executor::HandleId;

pub use executor::HandleSet;

pub use executor::InvocationMode;

pub use executor::NodeError;

pub use executor::RawAcceptedCallback;

pub use executor::RawCancelCallback;

pub use executor::RawGoalCallback;

pub use executor::RawResponseCallback;

pub use executor::RawServiceCallback;

pub use executor::RawSubscriptionCallback;

pub use executor::ReadinessSnapshot;

pub use executor::ShutdownCallbackFn;

pub use executor::ShutdownCallbackHandle;

pub use executor::ShutdownPhase;

pub use executor::SpinOnceResult;

pub use executor::SpinOptions;

pub use executor::SpinPeriodPollingResult;

pub use executor::Trigger;

pub use executor::baked_domain_from_c_abi;

pub use executor::ActionClient;

pub use executor::ActionClientCore;

pub use executor::ActionServer;

pub use executor::ActionServerCore;

pub use executor::ActionServerHandle;

pub use executor::ActionServerRawHandle;

pub use executor::ActiveGoal;

pub use executor::CallbackGroup;

pub use executor::CompletedGoal;

pub use executor::EmbeddedPublisher;

pub use executor::EmbeddedRawPublisher;

pub use executor::EmbeddedServiceClient;

pub use executor::EmbeddedServiceServer;

pub use executor::Executor;

pub use executor::FeedbackStream;

pub use executor::GoalFeedbackStream;

pub use executor::LoanError;

pub use executor::NodeHandle;

pub use executor::Promise;

pub use executor::PublishLoan;

pub use executor::RawActionClientSpec;

pub use executor::RawActionServerSpec;

pub use executor::RawActiveGoal;

pub use executor::RawServiceClient;

pub use executor::RawServiceServer;

pub use executor::RawSubscription;

pub use executor::RecvView;

pub use executor::SessionHandle;

pub use executor::Subscription;

pub use executor::action_channel_type;

pub use executor::executor_storage_layout;

pub use executor::executor_storage_u64_len;

pub use executor::ExecutorInlineStorage;

pub use executor::ExecutorSizing;

pub use executor::RMW_SELECTOR_CAP;

pub use executor::default_epoch_us_fn;

pub use executor::SessionSpec;

pub use executor::SpinPeriodResult;

Modules

boot_report

phase-412 – the boot self-report, for boards with no reachable log sink. A fixed RAM record the image writes about itself, for targets where no log sink reaches a human.

c_waker

Phase 122.3.c.6.e — C-ABI-compatible Waker bridge.

config

Build-time configurable constants.

executor

Embedded executor with build-time configured arena.

format_check

RFC-0088 / phase-421 W1 — the compile-time message-format check.

lifecycle

Lifecycle node API (REP-2002)

limits

Shared string-length and resource caps used by the Rust, C, and C++ APIs.

names

ROS 2 name expansion + launch remap resolution (issue 0255 / phase-306 W3).

rmw_type_registry

Phase 212.K.7.6.b — runtime cyclonedds type-descriptor registry hook. Per-type descriptor registration — generic seam (Phase 248 C2).

session

Concrete session type aliases resolved at compile time.

timer

Timer API for nros

Structs

ActionInfo

Action information for action client/server

BakedBootConfig

Build-time-baked boot config, emitted (in W4b) into the .nros_boot_config linker section by the entry macro / cmake. Fixed-size + pointer-free so a future post-link tool can patch it in place (RFC-0045). The resolver reads it on embedded via BootConfig::from_baked (in nros-node).

CdrReader

CDR reader for deserialization

CdrWriter

DHeaderMark

Opaque marker returned by CdrWriter::begin_dheader, passed back to CdrWriter::end_dheader. Under XCDR1 it carries nothing (the DHEADER calls are no-ops); under XCDR2 it holds the reserved DHEADER position.

DHeaderScope

Opaque scope returned by CdrReader::begin_dheader, passed back to CdrReader::end_dheader. Under XCDR1 it carries nothing (no-op); under XCDR2 it holds the absolute buffer offset of the delimited struct’s end.

GoalId

Unique identifier for a goal

NodeConfig

Node configuration

PublisherHandle

Handle to a publisher

PublisherOptions

Options for creating a publisher

QoSPolicyMask

Bitmask of QoS policies a backend can honour. See Session::supported_qos_policies.

QoSProfile

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

ServiceInfo

Service information for service client/server

StandaloneNode

ROS 2 Node for embedded systems

SubscriptionHandle

Handle to a subscriber

SubscriptionOptions

Options for creating a subscriber

TopicInfo

Topic information for pub/sub

TransportConfig

Transport session configuration

Enums

CancelResponse

Per-goal cancel decision returned from a server’s cancel callback.

CancelReturnCode

action_msgs/srv/CancelGoal RPC return codes.

DeserError

Deserialization error.

EncodingVersion

CDR writer for serialization.

GoalResponse

Goal accept/reject response codes

GoalStatus

Goal status states

LifecycleState

Lifecycle state (REP-2002)

LifecycleTransition

Lifecycle transition (REP-2002)

QoSDurabilityPolicy

QoS durability policy

QoSHistoryPolicy

QoS history policy

QoSLivelinessPolicy

QoS liveliness policy. Matches DDS LIVELINESS semantics.

QoSReliabilityPolicy

QoS reliability policy

SerError

Serialization error.

SessionMode

Session mode

StandaloneNodeError

Node error types

TransitionResult

Result of a lifecycle transition callback.

TransportError

Transport error types.

Constants

BOOT_SET_DOMAIN

Bit 2 — domain_id field is set.

BOOT_SET_LOCATOR

Bit 1 — locator field is set.

BOOT_SET_NAMESPACE

Bit 3 — namespace field is set.

BOOT_SET_NODE_NAME

Bit 0 — node_name field is set.

BOOT_SET_RMW

Bit 4 — rmw field is set (issue 1050 defect (3); layout version 2).

NROS_BOOT_CONFIG_MAGIC

0x4E524243 = ASCII “NRBC”. A post-link tool scans for this magic to locate the struct in a firmware image.

NROS_BOOT_CONFIG_VERSION

Layout version — lets the resolver reject a mismatched baked struct.

SERVER_DISCOVERY_PROBE_TIMEOUT_MS

Server-discovery probe cadence (issue #224 — one shared constant; was independently defined at four call sites across nros-node and nros-c). One probe per second balances “see freshly-declared tokens quickly” against “burn fewer FFI round-trips on a healthy network”; the outer wall-clock budget is the caller’s.

Traits

ClientTrait

Service client trait for sending requests.

Publisher

Publisher trait for sending messages.

ServiceTrait

Service server trait for handling requests.

Session

Transport session trait — the per-process anchor an RMW backend gives to the executor.

SubscriptionTrait

Subscription trait for receiving messages.