Класс: CurlDownloadStrategy

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# File 'download_strategy/curl_download_strategy.rb', line 36

def fetch(timeout: nil)
  end_time = Time.now + timeout if timeout

  download_lock = DownloadLock.new(temporary_path)
  begin
    download_lock.lock

    urls = [url, *mirrors]

    if (domain = Homebrew::EnvConfig.artifact_domain)
      artifact_urls = urls.map do |u|
        u.sub(%r{^https?://#{GitHubPackages::URL_DOMAIN}/}o, "#{domain.chomp("/")}/")
      end

      urls = if Homebrew::EnvConfig.artifact_domain_no_fallback?
        artifact_urls
      else
        # Interleave: try artifact domain first, then original for each URL that was rewritten.
        combined = []
        artifact_urls.zip(urls).each do |artifact_url, original_url|
          combined << artifact_url
          combined << original_url if original_url != artifact_url
        end
        combined
      end
    end

    begin
      url = T.must(urls.shift)

      ohai "Downloading #{url}"

      cached_location_valid = cached_location.exist?

      resolved_url, _, last_modified, @file_size, content_type, is_redirection = begin
        resolve_url_basename_time_file_size(url, timeout: Utils::Timer.remaining!(end_time))
      rescue ErrorDuringExecution
        raise unless cached_location_valid
      end
      @last_modified = last_modified

      # Caller-supplied headers (e.g. tokens) are no longer valid after a
      # redirect to another host, and `Authorization` after any redirect.
      if is_redirection
        if resolved_url && URI(url).host != URI(resolved_url).host
          meta.delete(:headers)
        else
          meta[:headers]&.delete_if { |header| header.start_with?("Authorization") }
        end
      end

      # The cached location is no longer fresh if either:
      # - Last-Modified value is newer than the file's timestamp
      # - Content-Length value is different than the file's size
      if cached_location_valid && (!content_type.is_a?(String) || !content_type.start_with?("text/"))
        if last_modified && last_modified > cached_location.mtime
          ohai "Ignoring #{cached_location}",
               "Cached modified time #{cached_location.mtime.iso8601} is before " \
               "Last-Modified header: #{last_modified.iso8601}"
          cached_location_valid = false
        end
        if @file_size&.nonzero? && @file_size != cached_location.size
          ohai "Ignoring #{cached_location}",
               "Cached size #{cached_location.size} differs from " \
               "Content-Length header: #{@file_size}"
          cached_location_valid = false
        end
      end

      if cached_location_valid
        puts "Already downloaded: #{cached_location}"
      else
        begin
          _fetch(url:, resolved_url: T.must(resolved_url), timeout: Utils::Timer.remaining!(end_time))
        rescue ErrorDuringExecution => e
          raise CurlDownloadStrategyError.new(url, e.stderr.strip)
        end
        cached_location.dirname.mkpath
        temporary_path.rename(cached_location.to_s)
      end

      create_symlink_to_cached_download(cached_location)
    rescue CurlDownloadStrategyError
      raise if urls.empty?

      puts "Trying a mirror..."
      retry
    rescue Timeout::Error => e
      raise Timeout::Error, "Timed out downloading #{self.url}: #{e}"
    end
  ensure
    download_lock.unlock(unlink: true)
  end
end

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# File 'download_strategy/curl_download_strategy.rb', line 143

def resolved_time_file_size(timeout: nil)
  _, _, time, file_size, = resolve_url_basename_time_file_size(url, timeout:)
  [time, T.must(file_size)]
end

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# File 'download_strategy/curl_download_strategy.rb', line 132

def total_size
  @file_size
end