VizIR is super slow. #7712
Description
Loading a page takes me about 12 seconds on a high-end desktop.
I recorded what's happening in Chromium with the performance profiler in the Developer Tools.
Trace-20230726T110312.json.zip
The first half of the time (below in green rectangle) is spent in init_tooltips, which calls out to some jQuery which takes all the time in querySelectorAll. The piece of offending code, according to the profile, is this one:
function init_tooltips(btns, prefix) {
var re = /(?:\-([^-]+))?$/;
for (var i = 0; i < btns.size(); i++) {
const button = btns[i];
const tooltip = $(prefix + re.exec(button.id)[1])[0];
button.is_clicked = false;
button.addEventListener('mouseenter', ()=>{
if (!button.is_clicked)
showTooltip(button, tooltip);
}
);
button.addEventListener('mouseleave', ()=>{
if (!button.is_clicked)
hideTooltip(tooltip);
}
);
button.addEventListener('click', ()=>{
if (button.is_clicked) {
hideTooltip(tooltip);
button.is_clicked = false;
} else {
showTooltip(button, tooltip);
button.is_clicked = true;
}
}
);
}
}The culprit is the $() call, I assume.
Second half of the time is spent in the same querySelectorAll but without a parent call.