Browse page performance

[dabreegster]

Loading 18MB of scheme data and filtering is still reasonably fast (a few seconds), but lag is noticeable. I did a little bit of profiling and have some ideas for improvements. I don't think any of this is important to do yet, but wanted to record these notes somewhere.

• addLineStringEndpoints takes 650-850ms. We're making a full defensive deep-copy unnecessarily, could improve this.
• addLineStringEndpoints is called twice when loading a file, because we lazily instantiate the Filters component, and because filtersUpdated gets called once upon creation.

[dabreegster]

When we update filters, we're modifying a per-feature property, which forces maplibre to reprocess all the GJ data. I tried using feature state, but:

• filtering on feature-state isn't supported
• we can set opacity to 0 based on feature state, but clicking/hovering still picks up the hidden features, so this doesn't work

So...

• Try using https://maplibre.org/maplibre-gl-js/docs/API/classes/maplibregl.GeoJSONSource/#updatedata in svelte-maplibre

[dabreegster]

• When typing free text in the filters, debounce requests. Or just update once the element loses focus

[dabreegster]

Oh yeah, and

• gzip the .gj file. If we make sure our GAE proxy sends the gzip header correctly, the browser will gunzip for us

[dabreegster]

Also tried out updateData; it'll get us a little bit of a win, but I have to make sure line endpoints have unique IDs. https://osmus.slack.com/archives/C01G3D28DAB/p1706714321758859 for notes / benchmark results