1949796 - Opening a big array is very slow in the json viewer

Status: RESOLVED DUPLICATE of bug 1901215

(DevTools :: JSON Viewer, defect, P2)

Description

[Julien Wajsberg [:julienw]]

STR:

1. Open https://firefoxci.taskcluster-artifacts.net/XA-uJyFdSJKZv_WlDez_nw/0/public/test_info/browsertime-results/speedometer3/pages/127_0_0_1/index.html/data/profile_power_1.json
2. Expand threads > 0 > samples > time

=> This freezes the tab.

Comment 1

[Julien Wajsberg [:julienw]]

Here is a profile: https://share.firefox.dev/41rPszR
I didn't wait until the end of the freeze as it's very very long. I guess we could shorten it with a smaller array, this one has more than 168k items.

Comment 2

[Julien Wajsberg [:julienw]]

The same operation with the same json object in the web console is much faster: https://share.firefox.dev/3EKlA8W

Comment 3

[Nicolas Chevobbe [:nchevobbe]]

Thanks for the report Julien.
We spend too much time in React rendering the array's items.
Like in the console, we could have some bucketting to avoid rendering too much at once.
Or we could have some fancier virtualization.