Question

My sinatra app has to parse a ~60MB XML-file. This file hardly ever changes: on a nightly cron job, It is overwritten with another one.

Are there tricks or ways to keep the parsed file in memory, as a variable, so that I can read from it on incoming requests, but not have to parse it over and over for each incoming request?

Some Pseudocode to illustrate my problem.

get '/projects/:id'
  return @nokigiri_object.search("//projects/project[@id=#{params[:id]}]/name/text()")
end

post '/projects/update'
  if params[:token] == "s3cr3t"
    @nokogiri_object = reparse_the_xml_file
  end
end

What I need to know, is how to create such a @nokogiri_object so that it persists when Sinatra runs. Is that possible at all? Or do I need some storage for that?

Answer 1

You could try:

configure do
  @@nokogiri_object = parse_xml
end

Then @@nokogiri_object will be available in your request methods. It’s a class variable rather than an instance variable, but should do what you want.