Crate gang_capability_topic_echo 

ROS 2 topic echo capability for Ganglion.

Subscribes to specified ROS 2 topics and captures serialized messages with optional decimation (sampling every Nth message). Designed for remote inspection of topic traffic without requiring a local ROS installation on the operator side.

When compiled to a WASM component this uses the ros-interface host import (topic-subscribe) to receive serialized messages. As a native library the capture and decimation logic is testable without ROS.

The design spec designates this as the C++ reference capability (wasi-sdk + wit-bindgen). The Rust crate implements the canonical logic; a C++ example project would demonstrate native-language parity for the ROS 2 community.

Structs

CapturedMessage

A single captured topic message.

EchoConfig

Configuration for a topic echo capture session.

EchoReport

Result of a topic echo session.

TopicStat

Per-topic statistics.

Functions

build_report

Build an echo report from pre-captured data (for testing and native mode).

decimate

Apply decimation to a stream of raw messages for a single topic.

format_report

Format an echo report as human-readable text.

parse_args

Parse CLI arguments into an EchoConfig.