can_tools

Utilities for parsing and working with automotive CAN data in Rust.

Features

• DBC parser – load .dbc databases into structured types.
• ASC parser – read .asc traces and build an in-memory CanLog.
• Decoupled model:
  • CanFrame: timing + channel + direction + pointer to MessageLog.
  • MessageLog: id, name, payload, comment, list of signal indices.
  • SignalLog: aggregated time-series for a decoded signal (values: Vec<[timestamp, value]>).
• Helpers – resolve_message_signals and SignalLog::value_text_at(ts).
• Normalizes units by stripping the "Unit_" prefix when present.

Quickstart

use can_tools::{dbc, asc, CanLog, resolve_message_signals};

fn main() -> Result<(), String> {
    // Load one or more DBCs and map them to channels
    let db = dbc::parse::from_file("path/to/file.dbc")?;
    let mut dbs = std::collections::HashMap::new();
    dbs.insert(1u8, db);

    // Parse an ASC trace
    let mut log = CanLog::default();
    let mut last_by_id_ch = std::collections::HashMap::new();
    let mut chart_by_key = std::collections::HashMap::new();
    asc::parse::from_file("path/to/file.asc", &mut log, &dbs, &mut last_by_id_ch, &mut chart_by_key)?;

    // Walk first frame
    let frame = &log.all_frame[0];
    let msg = &log.messages[frame.message];
    println!("id={} name={}", msg.id, msg.name);

    // Iterate message signals
    for sig in resolve_message_signals(&log, frame.message) {
        if let Some((v, txt)) = sig.value_text_at(frame.timestamp as f64) {
            println!("{} = {} ({})", sig.name, v, txt);
        }
    }
    Ok(())
}

Design notes

• CanFrame is intentionally small: sorting and paging remain fast.
• Message and Signal data are centralized to avoid duplication and to make charting efficient.
• SignalLog.values uses pairs [timestamp, value] in seconds.
• SignalLog.value_text_at(ts) uses the signal's own factor/offset to reverse-map the raw integer and look up its text via value_table.

License

MIT