[Libreoffice] Proposal: slowcheck -- some numbers for sc

Michael Stahl mst at openoffice.org
Thu Sep 22 09:47:02 PDT 2011

On 21.09.2011 13:08, Lubos Lunak wrote:
> On Wednesday 21 of September 2011, Michael Meeks wrote:
>> On Wed, 2011-09-21 at 09:50 +0100, Caolán McNamara wrote:
>>> In an ideal world I imagine the best spent effort would be on improving
>>> the import speed for .ods and .xlsx, seeing as that improves the
>>> real-world case too.
>> 	Agreed. Assuming that the files are of equivalent on-disk size, it's
>> amusing that the old code is fastest and the newest slowest. It'd be
>> really interesting to get a callgrind trace of ods / xlsx loading.

well nobody ever claimed that XML is faster to parse than binary gunk; it
is, however, far easier to import in C/C++ without accidentally
compromising the user's system in the process  :-/

>  Amusing maybe, but not strange at all. XLS is binary format, ODS and XLSX are 
> XML-based. Any guesses on how much slower image loading would be if somebody 
> came up with JPEGX? And, if calc import filters are written in at least 
> somewhat similar way to writer import filters, then XML-based filters get 
> additional penalty for XSL processing and abstractions, especially in a 
> non-optimized build.

AFAIK importing an ODF or OOXML file won't use any XSLT stuff; that is
only for less popular formats.

"This article, then, is a serious analysis of a ridiculous subject,
 which is of course the opposite of what is usual in economics."
 -- Paul Krugman, "The Theory Of Interstellar Trade",
    Economic Inquiry, Vol. 48(4), p. 1119-1123

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