Streaming plots

A quick and easy way to add low-latency time series plots and browser-accessible logs to Rust applications.

Run the demo via and navigate to http://localhost:3004/

cargo run --example demo

Priorities

• ease of use approaching println
• low resource usage both ends (suitable for Raspberry Pi servers and old phone/tablet clients)

Non-priorities

• other plot types

• API stability; add to your project's Cargo.toml as:

  splot = { git = "https://github.com/lynaghk/splot", rev = "< SHA of commit you've reviewed here >" }
  

TODO

Roughly in descending priority order:

• example of redirecting logging
• add Raspberry Pi usage example
• don't reset zoom/interaction when new data arrives
• add esp32 usage example (likely requires alternative HTTP server implementation)
• Rust API rather than inlining uPlot config as JS
• characterize disconnect/reconnect behavior when no updates (can we rely on browser/networking stack to heartbeat, or does this need to happen at application level?)
• compare current HTTP streaming approach with websockets (PRs welcome)

notes on alternative plotting libs

https://huww98.github.io/TimeChart/demo/ 11kB minified JS webgl chart using shadow DOM, looks tidy. leans on d3 for SVG DOM scale, etc. can only use single-precision floats for, so data may need to be scaled before it can be rendered. first paint is 500ms faster for uPlot than TimeChart according to TimeChart author https://huww98.github.io/TimeChart/docs/performance

https://github.com/plotters-rs/plotters-wasm-demo all rust drawing to canvas, no 80kB wasm blob