fn download_tempfile()

in src/api/sync.rs [576:617]

• 35 lines of code
• 5 McCabe index (conditional complexity)

    fn download_tempfile<P: Progress>(
        &self,
        url: &str,
        size: usize,
        mut progress: P,
        tmp_path: PathBuf,
        filename: &str,
    ) -> Result<PathBuf, ApiError> {
        progress.init(size, filename);
        let filepath = tmp_path;

        // Create the file and set everything properly

        let mut file = match std::fs::OpenOptions::new().append(true).open(&filepath) {
            Ok(f) => f,
            Err(_) => std::fs::File::create(&filepath)?,
        };

        // In case of resume.
        let start = file.metadata()?.len();
        if start > size as u64 {
            return Err(ApiError::InvalidResume);
        }

        let mut res = self.download_from(url, start, size, &mut file, filename, &mut progress);
        if self.max_retries > 0 {
            let mut i = 0;
            while let Err(dlerr) = res {
                let wait_time = exponential_backoff(300, i, 10_000);
                std::thread::sleep(std::time::Duration::from_millis(wait_time as u64));

                let current = file.stream_position()?;
                res = self.download_from(url, current, size, &mut file, filename, &mut progress);
                i += 1;
                if i > self.max_retries {
                    return Err(ApiError::TooManyRetries(dlerr.into()));
                }
            }
        }
        res?;
        Ok(filepath)
    }