lb-sparkplugb-rs (sparkplug_b)

A standalone, spec-driven Rust implementation of the Eclipse Sparkplug B 3.0.0 specification: the wire payload model + codec, the topic namespace, the sequence/bdSeq machinery, and (phased) the Edge Node and Host Application roles.

The crate has no dependency on any SCADA framework. The protobuf codec is hand-written (no protoc/prost-build), so the only runtime dependencies are bytes and thiserror (plus optional flate2 for the compression feature).

Status

See ../docs/plan-lb-sparkplugb-rs-sparkplug-b.md for the full plan, and ../docs/sparkplug-b-normative-statements.md for the conformance catalog.

Example

use sparkplug_b::{decode, encode, EncodeOptions, Metric, MetricValue, Payload};

let payload = Payload::new()
    .with_timestamp(1_700_000_000_000)
    .with_seq(0)
    .with_metric(Metric::new("Temperature", MetricValue::Double(21.5)));

let bytes = encode(&payload, EncodeOptions::birth());
let decoded = decode(&bytes, None).unwrap();
assert_eq!(decoded, payload);

cargo run --example encode_nbirth

Build & test

cargo build --all-features
cargo test  --all-features
cargo clippy --all-targets --all-features -- -D warnings
cargo fmt --check

Design notes

• Tagged-enum values (MetricValue) make type/value mismatch unrepresentable.
• Topic is an enum (Node | Device | HostState); one canonical parser.
• seq/bdSeq are u8 — wrapping_add gives the spec's 255 -> 0 wrap.
• Decoding never panics on hostile input — every failure is a typed SparkplugError; arbitrary-bytes fuzzing is a property test.

Licensing

This implementation is original (Apache-2.0 OR MIT). It is informed by the Eclipse Tahu reference implementation (EPL-2.0) but copies no Tahu source; the Sparkplug protobuf schema (field numbers / enum values) is factual.