Ruby on V8

Jump to Comments

Google Chrome looks cool, ok… But what is even cooler for me is V8, the super JavaScript VM.

JavaScript is a dynamic language, just like Ruby.
You can add stuff to objects at runtime, like Ruby.
It’s object oriented, like Ruby.
It has a GC, like Ruby.
…

What if we could run Ruby on V8?

Well, it’s a lot easier that you think. If you remember a while ago, someone released HotRuby. It runs YARV bytecode in the browser.

So I plugged the 2 together just to see what would happened => rbv8.

It’s fast (sometimes)

I used the script on HotRuby site to benchmark.

sum = ""
50000.times{ |e| sum += e.to_s }

And just for fun, I also wrote it in C:

int main (int argc, char const *argv[])
{
  char *str = malloc(sizeof(char) * 238890);
  char buf[5];
  size_t i;

  for (i = 0; i < 50000; ++i) {
    sprintf(buf, "%d", i);
    strcat(str, buf);
  }
  return 0;
}

Update: seems like my C code was the suck, thx for some commenters for pointing it out. Here’s a better version which is way faster (thx to Hongli Lai):

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main (int argc, char const *argv[])
{
  char *str = malloc(sizeof(char) * 238890);
  char buf[5];
  size_t i;
  unsigned long last = 0;

  for (i = 0; i < 50000; ++i) {
    int len = sprintf(buf, "%d", i);
    memcpy(str + last, buf, len);
    last += len;
  }
  return 0;
}

Also here’s a Javascript version:

var sum = "";
for (var i = 0; i < 50000; i++) {
  sum += i.toString();
};

C:              0.017 sec
Javascript:     0.063 sec
rbv8:           0.987 sec
Firefox 3:      3.636 sec
Safari 3:       4.368 sec
Opera 9.50:     4.679 sec
Ruby 1.8.6:     9.565 sec
Ruby 1.9.0:     9.669 sec
Rubinius 0.8.0: 15.576 sec
JRuby 1.1 b1:   42.691 sec

OMG OMG OMG OMG!!! 10 times faster then YARV and faster then C!

Update: Ok… if your replace += w/ <<, YARV beats the Javascript version running on V8, thx to Nobu Nakada for noting this

But wait, don’t go tell your friends yet! It seems, that all the other benchmarks I tried were slower (sometimes by a very wide margin).

But I think this means that the potential is there, it just need to be exploited properly.

Also another fun thing to note, is that if you change Fixnum#times to while i < 50000 in the Ruby code, it becomes a lot slower. No idea why.

Me wants to try

If you wanna try rbv8:
You need Ruby 1.9 installed as `ruby19` and make sure you meet V8 Pre-requisites: http://code.google.com/apis/v8/build.html#pre_reqs.

git clone git://github.com/macournoyer/rbv8.git
cd rbv8
rake
bin/rbv8 sample/concat.rb

Note that this is just a prototype. I just hacked this in an hour to benchmark it. See the README file for what needs to be done next.

---

Possibly related posts: (automatically generated)

• Ruby to C, a couple snippets

55 Comments

Filed under ruby