From: Joseph McDonald <joe@...>
Date: 2002-07-01T00:50:41+09:00
Subject: Re: select loop question


NF> Just do

NF>         answer[0].each {|r| readfds.delete(r)}

Thanks,  I do notice that Array.delete seems to be very slow, If I run this:

hits = (200..300).to_a
1.upto(1000) do

  arr = []
  1.upto(500) do |x|
    arr.push(x)
  end

  # hits.each do |h|
  #  arr.delete(h)
  # end

end

I get:
     0.47 real         0.46 user         0.00 sys
If I uncomment out the delete portion I get:
      8.74 real         8.23 user         0.00 sys
      
My guess is that it is doing the cartesion product thing, interesting
that it is 8 times slower than:

  arr.each do |x|
    if x >= 200 and x <= 300
      arr.slice!(x)
    end
  end

which gives:  1.09 real         1.06 user         0.00 sys

another surprising thing, if I use: arr = arr - hits

gives:       24.36 real        21.91 user         0.03 sys

thanks,
-joe