Which library does the progress bar depend on in cargo?

JesseAtSZ · January 5, 2022, 4:44pm

Which library does the progress bar depend on in cargo? I want to add a progress bar to my project, so I want to learn from it.

Michael-F-Bryan · January 5, 2022, 5:13pm

It looks like they implemented their own progress bar. I'm guessing that's because nothing existed that quite fit their needs when first implementing cargo.

github.com

rust-lang/cargo/blob/1a8692df1112dfde43a3bd73ac52aeea4c128f62/src/cargo/util/progress.rs#L201-L227

    
      
          fn print(&mut self, prefix: &str, msg: &str) -> CargoResult<()> {
              self.throttle.update();
              self.try_update_max_width();
          
          
    // make sure we have enough room for the header
              if self.format.max_width < 15 {
                  return Ok(());
              }
          
          
    let mut line = prefix.to_string();
              self.format.render(&mut line, msg);
              while line.len() < self.format.max_width - 15 {
                  line.push(' ');
              }
          
          
    // Only update if the line has changed.
              if self.config.shell().is_cleared() || self.last_line.as_ref() != Some(&line) {
                  let mut shell = self.config.shell();
                  shell.set_needs_clear(false);
                  shell.status_header(&self.name)?;

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In the past, I've found the indicatif crate to be quite nice to work with and generate pretty output.

H2CO3 · January 5, 2022, 5:15pm

+1 to indicatif, that's the one I think has the best bang for the buck, in terms of features/nice display vs. API complexity/usability.