Erik on Rails

This code¹:

crops.each do |c| 
  c.calculate_status(user)
end

takes 0.3 seconds to run. This code:

crops = crops.to_a 
while(c = crops.shift)
  c.calculate_status(user)
end

takes 0.00001 seconds to run. Using shift lets Ruby clear that junk out of memory as soon as you leave the current iteration of your while loop. Each makes you keep it around.

Be advised.

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Tags: activerecord, performance, ruby

This entry was posted on Tuesday, February 14th, 2012 at 4:21 am and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.