[JW Lua] ForEachInteger processing speed ? Very slow on high ranges

[Jan Angermüller]

Jari,

I noticed that ForEachInteger is extremly slow on loops with high ranges.
And that there is an*incredible speed boost* on these loops, if the 
script is run a second time.

With the simple print-loop code snippet at very bottom, I get the 
following results for processing time, if I run the loops with these 
values in this order:

endloop=10000   -> 0.214s
endloop=20000   -> 0.813s
endloop=60000   -> *14.928s*
endloop=160000   -> *134.258**s* (!)
endloop=20000   -> 0.071s (run again with the same 20000   value)
endloop=60000   -> 0.221s (run again with the same 60000 value)
endloop=160000   -> 0.566s (run again with the same 160000 value)
endloop=80000 -> 0.282s (although this value was not yet calculated it's 
now done very quickly. Probably because the value 80000 is below the yet 
highest value of 160.000)

If you look more deeply into these numbers, it looks like for example in 
the 160.000 loop the 60.000 elements that were calculated in the 
previous run of the script were calculated extremly fast and only the 
remaining new 100.000 elements took very long.
So if I restart Finale and start with calling the script with 160.000, 
it even takes longer than 134 seconds.
When running the script again with a lower loop end value than before, 
the calculation time is linear and very fast.

Are the Pentium prefetching optimizations really so clever that they 
save 99% of the processing time ?
I think there must be problem in the implementation as I don't know why 
this simple print loop should take 50s on only 180.000 iterations on a 
high speed PC. Maybe it's an iterative memory allocation problem: only 
the first time the memory is allocated and then kept free for further 
loop calls.

Jan

function DoCallback(i)
print("Callback"..i)
end

local it=finale.FCLuaIterator()
it.UseProgressBar=true
it.AbortableProgressBar=false
it.ProgressUpdateFrequency=1
local endloop=....  --(take value from above)
it:ForEachInteger(1,endloop,DoCallback)
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