Eliot, Sven, Stephan,
thank you for your answers.
As you noticed I am not an expert in profiling :-)
it seems now I might have goofed up and the time taken by pharo in my
initial program (compared to java) is due to some other extra
compilation I was doing.
So the "macro benchmark" might be wrong
Still the "micro benchmark" still holds
I tested the code proposed by Elliot and the result is ....
---
[1 to: 10 do: [:j || a length |
length:=0.
a :=
'/home/anquetil/Documents/RMod/Tools/workspace/Blocks/jfreechart-0_9_0.mse'
asFileReference readStream contents.
1 to: a size do: [ :i| | c | c:= a at: i. length:= length+1]]]
timeToRunWithoutGC
---
12.723 sec.
[reminder] For java it is: 1.482 sec.
so it is still a factor 8 or 9
it seems a lot for such a simple thing, no?
(or maybe not, I don't know)
nicolas
On 16/03/2015 09:49, Nicolas Anquetil wrote:
I have been doing some file intensive activities and found my program
to be VERY slow (see at the end).
Just to be sure I ran them in Java and found it was much faster
So I did a small test:
---
[10 timesRepeat: [i := 0.
'/home/anquetil/Documents/RMod/Tools/workspace/Blocks/jfreechart-0_9_0.mse'
asFileReference readStream contents do: [ :c | i:= i+1].
] ] timeToRunWithoutGC.
---
result = 12.932 sec
similar thing (as far as I can tell) 10 times in java: 1.482 sec.
---
public static void main(String[] args) {
int length =0;
try {
String filename =
"/home/anquetil/Documents/RMod/Tools/workspace/Blocks/jfreechart-0_9_0.mse";
String content = new
String(Files.readAllBytes(Paths.get(filename)), "UTF8");
for (int i=0; i < content.length(); i++) {
content.charAt(i);
length = length+1;
}
} catch (IOException e) {
e.printStackTrace();
}
System.out.println(length);
}
---
Because my program is MUCH slower (see at the end) in Smalltalk than
in Java, I did another experiment:
---
[1 to: 10 do: [:i| 1 to: 100000000 do: [:j | String new] ] ]
timeToRunWithoutGC.
---
result = 33.063 sec
and in java: 4.382 sec.
---[10 runs of]
public static void main(String[] args) {
for (int i=0; i < 100000000; i++) {
new String();
}
}
---
Concretly, my need was:
Take 2600 methods in a Moose model, take their source code (therefore
reading files), for methods longer than 100 lines (there are 29 of
them), go through there code to find the blocks (matching {}).
In smalltalk it ran > 12hours and I had processed 5 methods of the 29
long ones
I reimplemented in Java (basically, just changing from pharo to java
syntax) and it took 1 minutes to compute everything ...
:-(
On the good side, it was much easier to program it in smalltalk (about
half a day to think about the algorithm, experiement, implement, test)
than in Java (another 1/2 day, just to recode the algorithm that
already worked).
nicolas
