I was working on a little script earlier, which I thought was too slow
for my taste. It's now about 5-6x faster than it originally was.
Normally, this would've been enough, but being very curious about Ruby,
I tried to make it go even faster by using micro optimizations. Here
are some things I found out:
* Running your script with the -rprofile option is the first thing you
should do
* Using a Set instead of an Array when you only want to store unique
values can help make your code go faster
* Disabling the GC can slightly increase the speed of your script.
However, I don't think it's a good idea to use in larger applications
That's a few things I found out today. Does anyone else have quick
optimization tips?
I was working on a little script earlier, which I thought was too slow
for my taste. It's now about 5-6x faster than it originally was.
Normally, this would've been enough, but being very curious about Ruby,
I tried to make it go even faster by using micro optimizations. Here
are some things I found out:
* Running your script with the -rprofile option is the first thing you
should do
... if it's too slow.
* Using a Set instead of an Array when you only want to store unique
values can help make your code go faster
IMHO this is not a micro optimization, this is a changed design. A set
represents something entirely different from an array (although they
share some properties).
* Disabling the GC can slightly increase the speed of your script.
However, I don't think it's a good idea to use in larger applications
I don't think either.
That's a few things I found out today. Does anyone else have quick
optimization tips?
In no particular order: Create as few objects as possible. Watch out
where you can in place modifying methods of string vs. non bang
methods. Choose the appropriate abstractions. Don't prematurely
optimize.
Kind regards
robert
···
2006/3/14, Vincent Foley <vfoleybourgon@yahoo.ca>:
open( file_name) do |inf|
inf.each_line do |line|
line.chomp! # Optimization Tip, use chomp! instead of
# line = line.chomp
next unless line =~ %r{Looks right}x #do stuff
end
end
try...
File.read( file_name).scan(%r{ what I'm actually looking for}mx) do |m|
# Do _stuff
end
Much much faster!
Always remember change of algorithm can get you 2 orders of magnitude speed, optimization tweaks usually around factors 1.5
No code is faster than No Code.
Native code is very much faster than Ruby.
eg. I wrote a ring buffer class in Ruby but found unless it grew to about 2000 elements using Array.shift and unshift was faster.
Benchmark class is the the optimizers friend.
John Carter Phone : (64)(3) 358 6639
Tait Electronics Fax : (64)(3) 359 4632
PO Box 1645 Christchurch Email : john.carter@tait.co.nz
New Zealand
Carter's Clarification of Murphy's Law.
"Things only ever go right so that they may go more spectacularly wrong later."
From this principle, all of life and physics may be deduced.
···
On Wed, 15 Mar 2006, Vincent Foley wrote:
That's a few things I found out today. Does anyone else have quick
optimization tips?
I have something else that is probably common knowledge: if you can
avoid using regular expressions, do it. By replacing the regex matches
in my script with string operations, I increased the runtime speed by a
factor of ~4.
In no particular order: Create as few objects as possible. Watch out
where you can in place modifying methods of string vs. non bang
methods. Choose the appropriate abstractions. Don't prematurely
optimize.
Just clarification: you are saying in-place is faster right?
~S
However, if you can replace a few Ruby operations with one complicated search and replace, sometimes it works the other way. It depends on the problem.
James Edward Gray II
···
On Mar 15, 2006, at 6:33 AM, Vincent Foley wrote:
I have something else that is probably common knowledge: if you can
avoid using regular expressions, do it. By replacing the regex matches
in my script with string operations, I increased the runtime speed by a
factor of ~4.
Warning, this may be hazardous for your health, but it works for me.
ps. Anyone worked out how to use gcc profile feedback to build a faster
ruby yet?
There was a good article on using profiling information to optimize GCC
builds in the RedHat magazine (iirc). I've been interested in trying it
with Ruby since I read it. I'm thinking that profiling it with ruby-tests
and the test suites of a couple of major gems would be a good way to
go.
Since Ryan's announcement of multiruby, I've been procrastinating
with a specific target instead of just idley thinking I should do it.
Now that I've announced it publicly, I should have even more reason
to try it out.
···
On 3/16/06, John Carter <john.carter@tait.co.nz> wrote:
John Carter Phone : (64)(3) 358 6639
Tait Electronics Fax : (64)(3) 359 4632
PO Box 1645 Christchurch Email : john.carter@tait.co.nz
New Zealand
Carter's Clarification of Murphy's Law.
"Things only ever go right so that they may go more spectacularly wrong later."
From this principle, all of life and physics may be deduced.
"Shea Martin" <null@void.0> wrote in message news:MNFRf.43456$VV4.659574@ursa-nb00s0.nbnet.nb.ca...
In no particular order: Create as few objects as possible. Watch out
where you can in place modifying methods of string vs. non bang
methods. Choose the appropriate abstractions. Don't prematurely
optimize.
Just clarification: you are saying in-place is faster right?
Right. But not applicable everywhere (i.e. if you're not allowed to modify something or do not know whether something is frozen...).