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Re: Patch to make string-append on win32 100 times faster

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From:
Wolfram Humann
Date:
August 17, 2010 01:09
Subject:
Re: Patch to make string-append on win32 100 times faster
Message ID:
4C6A43C1.2070708@arcor.de
-------- Original Message --------
Subject: Re: Patch to make string-append on win32 100 times faster
From: Jan Dubois <jand@activestate.com>
To: 'David Golden' <xdaveg@gmail.com>, 'Reini Urban' <rurban@x-ray.at>
Date: 17.08.2010 01:09
> On Mon, 16 Aug 2010, David Golden wrote:
>   
>> I think I'm with Reini on this one. I'd rather keep it Windows-only until a
>> performance problem is documented elsewhere.
>>     
>
> It's been documented that the patch improves performance on FreeBSD by a
> *factor* of 160 for one particular test case, as well as a factor of 4
> on Linux. In the meantime Wolfram has constructed another testcase where
> the patch improves performance on Linux by a factor of 45 (my system) to
> 230 (Wolfram's system).
>
> Granted, these are worst-case samples, but at least the first test
> program was derived from a real-world application: appending lots of
> small strings to an ever-growing large buffer.
I think that even my worst-case Linux test case is not totally 
out-of-the-world. It occurs whenever a large number of strings grows 
simultaneously by small increments. One application that comes to mind 
is pivoting (exchanging rows and columns of) a large text-based table: 
loop over the lines, splitting each row and appending the chunks to the 
respective column's string; finally print the column strings as new rows 
when the complete table is read.

Wolfram
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