GitHub pages hosting .pmtiles not always working?

[jamaps]

Hi y'all

I've been using GitHub pages to host smaller .pmtiles (<50mb or so) for the past few months (and mostly loading and styling them in maplibre). Has been working great!

But recently I'm seeing that .pmtiles files hosted via Github pages are sometimes not loading and returning errors like this in my web browser:

• In Chrome, Error: Server returned no content-length header or content-length exceeding request. Check that your storage backend supports HTTP Byte Serving.

• In Firefox, "Decoding failed."

My projects still work perfectly fine when testing locally and loading local files, or when loading .pmtiles coming from anywhere else other than a GitHub repo.

Anyone know if GitHub pages has changed how they serve .pmtiles or similar files that rely on range requests? or have any other ideas?

(Noticing as well that Chrome seems to not error as much compared to Firefox, but I don't really understand why there would a browser difference).

Thanks!

~ Jeff

[bdon]

What version of the pmtiles js library are you using?

In v3.1.0 it was changed to explicitly disable reading from browser cache on Chrome because of a Chrome bug:

https://github.com/protomaps/PMTiles/blob/main/js/CHANGELOG.md

That wouldn't explain why Firefox fails this way though.

If you are able to reproduce it, can you see if it is attempting to read the byte range from cache?

[jamaps]

Hi

This is one of a few projects where I'm noticing the issue in Firefox, using pmtiles v3.2.1
https://schoolofcities.github.io/transportation-tomorrow-survey/

(I have not experienced any issues with Chrome for 5-6 days - Safari, Edge, etc. all work fine too)

In Firefox, in the network tab, it seems to be making one successful request (206), and then any additional request for tiles are blank ("No headers for this request" when I try to look at additional details).

The first request has the following in the request header, so I think it is caching it.
accept-ranges bytes
content-range bytes 0-16383/9274689
cache-control max-age=600

Not really sure whats going on here - a bug in how Firefox handles partial caching? - any subsequent range requests are made to the first requested cached piece and are thus then out of range? (Chrome has the same request headers but any subsequent requests are made to the .pmtile file on GitHub pages, not the 16kb cached version)

[bdon]

I think this is the same issue: #272 (comment)

I can reproduce it on https://pmtiles.io/examples/maplibre.html with stock Firefox which is bad. Investigating...