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Firefox Developer Tools support flame charts, but it seems time is used as X-axis:

In the Flame Chart view itself, along the X-axis is time. The screenshot above covers the period from 1435ms to a little past 1465ms. Along the Y-axis are the functions on the call stack at that point in time, with the top-level at the top, and the leaf function at the bottom. Functions are color-coded to make them easier to distinguish.

Usually, flame charts use percentage as X axis, for instance: pyflame or Brendan Gregg's flame graphs.

I find the time-based flame charts confusing and miss the ability to get aggregated times per function (similar to Call Tree as far as content is concerned, but represented in more visual way). Also, if a function is short but is called many times it is easy to miss it, while on "aggregated" flame charts it would stand out prominently. To see why time-based flame charts are confusing, let me borrow example from another post - admittedly in Chrome, but the problem is similar:

enter image description here

Even if some function took 30% of total time, that would not be visible in the above chart.

Is there any way (through plugin or setting) I can make Firefox display aggregated flame charts for the selected time slice instead of time-based ones?

johndodo
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  • You're rediscovering the [*problem with flame-graphs*](https://stackoverflow.com/a/25870103/23771), in spite of their cuteness. There's [*another method*](https://stackoverflow.com/a/27867426/23771) that does work. – Mike Dunlavey Jan 26 '18 at 15:27
  • Not really. I am aware of their limitations and can use them just fine. My issue is that these things in Chrome and Firefox are not really flame graphs. The data is there, but it is not aggregated so it is much less visible as it should be - and this is the problem I am looking to solve. – johndodo Jan 26 '18 at 20:12

1 Answers1

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It seems that extending the DevTools is fairly limited, unless you're creating your own panel, but you don't really have access to the profiler in there to generate your Flame Graph.

You can still save your recorded profile into a JSON file, parse it, and create your own Flame Graph that can calculate total aggregated runtime.

You can also try the Gecko Profiler Add-on for some more advanced profiling. You'll be in the same boat though, in that you'd need to export it to do your own aggregations on the profile data.

mootrichard
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