On Thu, Feb 21, 2008 at 11:24 PM, Kyle Hunter <keletmaster / gmail.com> wrote:
> Hello,
>
>  I've got an array that holds urls. Example Element:
>  http://bla.random.com/bla.jpg.
>
>  I also have images in a directory. I'd like my script to compare the
>  bla.jpg from the URL with all files in a directory to make sure it's not
>  a duplicate of something that's already there - if it is - delete it
>  from the array. My current way of doing it uses quite a bit of
>  resources, was wondering if someone could show me a more efficient
>  example if possible.
>
>  Current Code:
>  Dir["#{$baseDir}/#{board}/#{$dateString}/**"].each do |file|
>       $imgArray.delete_if{
>         |i| i =~ /#{file.split('/').pop}/
>       }

1. use file.split('/').last instead of pop - pop modifies the array

2. move the regex out of the block - you'll save some object
constructions/destructions, and it'll be easier on GC too.

3. try instead of splitting using a regex or rindex.
i.e. last_part = $1 if file =~ /\/([^/]*)$/
or last_part = file[file.rindex('/')..-1] or
file[(file.rindex('/')||0)..-1] to fix the cae when there's no '/' in
the filename.

4. use Benchmark class to measure your improvements - that way, you'll
know exactly if the new code is better or not.