[erlang-questions] 700% speedup

Ulf Wiger <>
Sat Jun 23 09:39:13 CEST 2007


A list of bytes uses 8x more memory than a corresp binary. I don't
know erlsom, but with xmerl you could try xmerl_eventp, which deeds
the scanner in chunks. It might help...

BTW, it's midsummer, so most Swedes are likely on vacation.

BR, Ulf W (using gmail on my mobile)

2007/6/22, Willem de Jong <>:
> It is a strange sory. The author claims to have achieved very good results
> using Erlang to parse a very big (35Mbyte) XML file (an Itunes Music Library
> file). He suggests that he uses lots of processes to do this.
>
> It made me curious, and I decided to do some tests.  I used my 1.7 GHz
> laptop with 1GB of memory, running Windows XP.
>
> - Parsing an Itunes file of 4Mbyte takes about 4 seconds with the SAX parser
> that is the basis of Erlsom (if you let the callback function do something
> trivial).
>
> - Parsing the file with Erlsom (which validates it against an XSD and
> translates it to records) takes about 5 seconds.
>
> - Parsing the file with Xmerl takes about 8 seconds.
>
> I found an article on parsing the Itunes library using mono
> http://www.xml.com/pub/a/2004/11/03/itunes.html). On an 800MHz powerbook
> parsing a 2.5Mbyte file apparently took 9 seconds, so I would say that
> Erlang doesn't look bad.
>
> Surprisingly, loading the file into Microsoft Internet Explorer takes more
> than a minute...
>
> If things would scale lineary, parsing the 35Mbyte file should take about 40
> to 80 seconds, which is about twice as fast as what the author of the blog
> claims to have achieved (on another machine, obviously, so comparing these
> figures may not make a lot of sense).
>
> Unfortunately, these tests fail miserably - Erlang crashes. On my machine I
> cannot translate a file (binary) of this size to a list. I have to say that
> I was a bit disappointed... Is there a way to fix this?
>
> Willem.
>
>
> On 6/20/07, Brad Anderson <> wrote:
> >
> > I came across this blog today...
> >
> > http://www.sungnyemun.org/wordpress/?p=323
> >
> > BA
> > _______________________________________________
> > erlang-questions mailing list
> > 
> > http://www.erlang.org/mailman/listinfo/erlang-questions
> >
>



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