Pass variables between separate instances of ruby (without writing to a text file or database)
- by boulder_ruby
Lets say I'm running a long worker-script in one of several open interactive rails consoles.
The script is updating columns in a very, very, very large table of records. I've muted the ActiveRecord logger to speed up the process, and instruct the script to output some record of progress so I know how roughly how long the process is going to take. That is what I am currently doing and it would look something like this:
ModelName.all.each_with_index do |r, i|
puts i if i % 250
...runs some process...
r.save
end
Sometimes its two nested arrays running, such that there would be multiple iterators and other things running all at once.
Is there a way that I could do something like this and access that variable from a separate rails console? (such that the variable would be overwritten every time the process is run without much slowdown)
records = ModelName.all
$total = records.count
records.each_with_index do |r, i|
$i = i
...runs some process...
r.save
end
meanwhile mid-process in other console
puts "#{($i/$total * 100).round(2)}% complete"
#=> 67.43% complete
I know passing global variables from one separate instance of ruby to the next doesn't work. I also just tried this to no effect as well
unix console 1
$X=5
echo {$X}
#=> 5
unix console 2
echo {$X}
#=> ""
Lastly, I also know using global variables like this is a major software design pattern no-no. I think that's reasonable, but I'd still like to know how to break that rule if I'd like.
Writing to a text file obviously would work. So would writing to a separate database table or something. That's not a bad idea. But the really cool trick would be sharing a variable between two instances without writing to a text file or database column.
What would this be called anyway? Tunneling? I don't quite know how to tag this question. Maybe bad-idea is one of them. But honestly design-patterns isn't what this question is about.
