This is a very advanced and resource efficient algorithm for expanding compressed content with Ruby:

def gunzip(filename)
  command = "gunzip --force #{filename}"
  success = system(command)
  
  success && $?.exitstatus == 0
end

To customize, change gunzip to whatever command you like.

For example, to avoid 100% CPU utilization during uncompression, set the niceness value of the command with nice -n 5 <command>:

command = "nice -n 5 gunzip --force #{filename}"

There's also ionice...

If you want you can also use GzipReader:

res = RestClient.get(url)
body = res.body
body = Zlib::GzipReader.new(StringIO.new(body)).read if res.headers[:content_type].include?('gzip')