Question

I have a controller that I am trying to grab XML files from remote sources.

Something like:

@artist = Nokogiri.XML(open(url).read)

However, I want to execute multiple of these at once getting different data. Can I use threads somehow?

Executing one by itself takes abut 400ms. So when they are executed three in a row the response is up to about 1s+.

Answer 1

Yes, you can use threads:

named_urls = {
  artist: 'http://foo.com/bar',
  song:   'http://foo.com/jim',
  # etc.
}
@named_xmls = {}
one_at_a_time = Mutex.new
named_urls.map do |name,url|
  Thread.new do
    doc = Nokogiri.XML(open(url).read)
    one_at_a_time.synchronize{ @named_xmls[name] = doc }
  end
end.each(&:join)

# At this point @named_xmls will be populated will all Nokogiri documents

I’m not certain if writing to different keys in a shared hash requires a Mutex or not, but it doesn’t hurt to be safe.