Performance Mystery Solved - IT'S THE DATA STUPID!!

[Richard Gaskin]

Monte Goulding wrote:

 > I never said it wasn't loaded into memory. I know it is and it
 > didn't make sense to me at the time that there would be such a
 > performance difference. Maybe it was something to do with
 > resolving the filename? I'm not sure, I just know it was slower.

There's probably some nuance I'm missing - here's a quick test which 
first uses the fileName of a stack to access a property, then the next 
run it opens the stack and gets the property by referring to the stack's 
short name (FWIW, I had saved the stack previously with its destroyStack 
set to true to try to maximize any load difference):


on mouseUp
   put 10000 into n
   put fld "file" into tStackFile
   --
   put the millisecs into t
   repeat n
     put the uTest of stack tStackFile into r1
   end repeat
   put the millisecs - t into t1
   --
   put the millisecs into t
   toplevel tStackFile
   put the short name of stack tStackFile into tStack
   repeat n
     put the uTest of stack tStack into r2
   end repeat
   close stack tStackFile
   put the millisecs - t into t2
   --
   put t1 && t2 &&(r1=r2) into fld "r"
end mouseUp

Result:  151 140 true

The difference is small even across 10,000 iterations, and can be 
explained by the need to resolve the path to a stack reference.

How can this test be modified to show a greater difference?

--
  Richard Gaskin
  Fourth World
  LiveCode training and consulting: http://www.fourthworld.com
  Webzine for LiveCode developers: http://www.LiveCodeJournal.com
  LiveCode Journal blog: http://LiveCodejournal.com/blog.irv