Thag_profiler_demo_part_1

by meanderthal 3 months ago

macOS • • zsh 28 views

Tip: View in full-screen mode for best legibility

Use f to toggle full-screen mode.

Steps

Use thag_instrument to make a copy of demo/document_pipeline.rs called demo/document_pipeline_instr.rs, instrumented for thag_profiler. We specify that the code being profiled is at Rust Edition 2021.

Compare the two files, showing that thag_instrument has added a thag_profiler import and annotated fn main with #[enable_profiling] and every other function with #[profiled].

Build and run the instrumented program to profile it. Since it’s a stand-alone thag script , we do so using thag demo/document_pipeline_instr.rs.

Now we are ready to analyse the profiling output. Since by default we wrote them to the current working directory, we specify that:

thag_profile .

Although we’ve profiled both execution time and memory, for the demo we’ll choose to view an aggregated time flamegraph. We choose Time Profile - Single, select the latest file document_pipeline_instr-20251013-213201.folded, then Show Aggregated Execution Timeline (Flamegraph). We then get to choose a color scheme and display the graph in the browser.

Since the lightweight asciinema tool can’t see the browser, we’ll exit at this point and return to view it in Part 2 with a heavyweight screen recorder.

https://asciinema.org/a/YP6mW01gYgW9EgZ5c01hL0vhc

Copied!

Append ?t=30 to start the playback at 30s, ?t=3:20 to start the playback at 3m 20s.

See sharing docs for more link customization options.

Embed as image link

Use snippets below to display a preview image linking to this recording.
Ideal for places where scripts are not allowed, such as project README files.

HTML:

<a href="https://asciinema.org/a/YP6mW01gYgW9EgZ5c01hL0vhc" target="_blank"><img src="https://asciinema.org/a/YP6mW01gYgW9EgZ5c01hL0vhc.svg" /></a>

Copied!

Markdown:

[![asciicast](https://asciinema.org/a/YP6mW01gYgW9EgZ5c01hL0vhc.svg)](https://asciinema.org/a/YP6mW01gYgW9EgZ5c01hL0vhc)

Copied!

Embed the player

If you're embedding on your own page or on a site which permits script tags, you can use the full player widget:

<script src="https://asciinema.org/a/YP6mW01gYgW9EgZ5c01hL0vhc.js" id="asciicast-YP6mW01gYgW9EgZ5c01hL0vhc" async="true"></script>

Copied!

Paste the above script tag where you want the player to be displayed on your page.

See embedding docs for more player customization options.

You can download this recording in asciicast v3 format, as a .cast file.

Download

Replay in terminal

You can replay the downloaded recording in your terminal using the asciinema play command:

asciinema play 748884.cast

Copied!

If you don't have asciinema CLI installed then see installation instructions.

Use with stand-alone player on your website

Download asciinema player from the releases page (you only need .js and .css file), then use it like this:

<!DOCTYPE html>
<html>
<head>
  <link rel="stylesheet" type="text/css" href="/assets/asciinema-player.css" />
</head>
<body>
  <div id="player"></div>
  <script src="/assets/asciinema-player.min.js"></script>
  <script>
    AsciinemaPlayer.create(
      '/assets/748884.cast',
      document.getElementById('player'),
      { cols: 203, rows: 30 }
    );
  </script>
</body>
</html>

See asciinema player quick-start guide for full usage instructions.

While this site doesn't provide GIF conversion at the moment, you can still do it yourself with the help of asciinema GIF generator utility - agg.

Once you have it installed, generate a GIF with the following command:

agg https://asciinema.org/a/YP6mW01gYgW9EgZ5c01hL0vhc demo.gif

Copied!

Or, if you already downloaded the recording file:

agg demo.cast demo.gif

Copied!

Check agg --help for all available options. You can change font family and size, select color theme, adjust speed and more.

See agg manual for full usage instructions.