Rust SDK silently drops data in some situations

[emilk]

Minimal reproduce:

use rerun::{
    components::{ColorRGBA, Point3D},
    time::{TimeType, Timeline},
    MsgSender, RecordingStreamBuilder,
};

fn main() -> anyhow::Result<()> {
    rerun::external::re_log::setup_native_logging();

    let (rec_stream, storage) = RecordingStreamBuilder::new("images").memory()?;
    let timeline = Timeline::new("keyframe", TimeType::Sequence);

    let pt = Point3D {
        x: 1.0,
        y: 1.0,
        z: 1.0,
    };

    MsgSender::new("world/pts")
        .with_time(timeline, 1)
        .with_component(&[pt])?
        .with_splat(ColorRGBA::from_rgb(161, 34, 212))?
        .send(&rec_stream)?;

    rerun::native_viewer::show(storage.take())?;

    Ok(())
}

Results in this:

Seems like data is lost somehow. Some flushing that is not being done?

[emilk]

Adding a call to rec_stream.flush_blocking(); before storage.take(); solves it.

We should at least warn when data is being silently lost, and document the behavior properly.

Maybe we could make take() block until data is flushed.

[teh-cmc]

Yeah, I think the most user-friendly solution here would be to do the same thing we do in the jupyter notebook internals in Python, namely: internally keep track of the RecordingStream associated with this MemorySinkStorage, and flush on behalf of the user where it makes sense.

It's a bit blurry how all of this works though, I'll have a quick look to see what's possible.