Groovy Timer and Performance Got a call from my good friend of mine mentioning groovy is slow in computation. Well, I had to agree with him that groovy might be slower than plain old Java classes. But i'm sure that will improve over time.

Our conversation start with him creating a simple script which loop 100,000 times performing simple mulitplication. He uses Linux for this test and it takes him around 2 min. I was surprise! Thus I did my own performance test with the follow script (Using tips from Groovy's Project Manager blog, Timing a closure in Groovy :D)

timer = { closure ->
 start = System.currentTimeMillis()
 closure.call()
 println System.currentTimeMillis() - start
}

// define an array with value 1 to 100000
def rates = 1..100000

println 'Performing 1st Test with .times'
timer {
 def a = 10
 def b = 2
 100000.times {idx-> a*rates[idx] }
}

println 'Performing 2nd test with for'
timer {
 def a = 10
 def b = 2
 for(int i=0;i<100000;i++) {
  a*rates[i]
 }
}

For the 1st test, it took 187ms on my window machine and 2nd test took 62ms. Phew... Anyway we are going to exchange information on our finding.

Labels: Groovy

  ¶ 5:54 PM 0 Comments

  Fun with Groovy My colleague had a great idea for groovy's implementation

def list = []
while (list.size()<6) {
    def num = new Random().nextInt(45)+1
    if (!list.contains(num)) list << num
}
println list

This will be my most-used groovy script. :D

Labels: Daily, Groovy

  ¶ 2:32 PM 0 Comments

  Quick file rename with Groovy Recently I have been learning the syntax of regular expression. Now regular expression + (Groovy of course) become part of my 'toolset' for my daily computer usage. A very quick and easy demonstration of what I meant here..

Lets say you downloaded you favourite TV shows and you wish to rename all your .avi files into a standardize format.

E.g. You have the following files
D:\Heroes\Heroes.S01E12.HDTV-LOL.avi
D:\Heroes\heroes.S01E13.HDTV.XviD-FPN.avi
D:\Heroes\Heroes.S01E14.HDTV-LOL.avi

instead of renaming the file one-by-one, use the following code

def sourceFolder = 'D:\\Heroes'
new File(sourceFolder).eachFile {
  def p = /[hH](eroes)\.S?0?(\d)E?(\d\d?).*/
  if ( it.getName() ==~ p ) {
    def s = (it.getName() =~ p).replaceFirst('H$1.S0$2E$3.avi')
    println "${it.getName()}\n${it.getParent().toString()}\\${s}\n"
    assert it.renameTo(new File("${it.getParent().toString()}\\${s}"))
  }
}

Your files should be rename to
D:\Heroes\Heroes.S01E12.avi
D:\Heroes\Heroes.S01E13.avi
D:\Heroes\Heroes.S01E14.avi

Labels: Groovy

  ¶ 3:57 PM 0 Comments