Question

While I am developing my application I need to do tons of math over and over again, tweaking it and running again and observing results.

The math is done on arrays that are loaded from large files. Many megabytes. Not very large but the problem is each time I run my script it first has to load the files into arrays. Which takes a long time.

I was wondering if there is anything external that works similarly to arrays, in that I can know the location of data and just get it. And that it doesn’t need to reload everything.

I don’t know much about databases except that they seem to not work the way I need to. They aren’t ordered and always need to search through everything. It seems. Still a possibility is in-memory databases?

If anyone has a solution it would be great to hear it.

Side question – isn’t it just possible to have user entered scripts that my ruby program runs so I can have the main ruby program run indefinitely? I still don’t know anything about user entered options and how that would work though.

Answer 1

Use Marshal:

# save an array to a file
File.open('array', 'w') { |f| f.write Marshal.dump(my_array) }

# load an array from file
my_array = File.open('array', 'r') { |f| Marshal.load(f.read) }

Your OS will keep the file cached between saves and loads, even between runs of separate processes using the data.