On 11/3/2008 9:20 AM, Hussein Shafie wrote:
> Andy Black wrote:
>> We've just learned that a large (540KB) XML file for one of our
>> custom configurations loads very slowly in version 4.1.0. In version
>> 3.8.1 it takes about 12 seconds, but in 4.1.0 it takes about 5
>> minutes and 20 seconds. We are using the Personal Edition in both
>> cases.
>>
>> Is this a known problem? (I tried looking for something on this in
>> the archives for this list, but did not find anything.)
>>
>> 12 seconds to load is fine, but over 5 minutes is a bit daunting.
>> Are there plans to address this?
>
> I'm almost sure you are comparing XXE v3.8.1 with custom configuration
> A to XXE v4.1 with custom configuration A' (which is enhanced custom
> configuration A).
Ah, yes. You are correct.
>
> Your CSS style sheet contains many rules like this one:
> ---
> iword item
> {
> display:block;
> color: concatenate(xpath("id(@lang)/@color"));
> font-family: concatenate("'",xpath("id(@lang)/@font-family"),"'");
> font-size: concatenate(xpath("id(@lang)/@font-size"));
> font-style: concatenate(xpath("id(@lang)/@font-style"));
> font-weight: concatenate(xpath("id(@lang)/@font-weight"));
> }
> ---
>
> The performance problem comes from the "id()" XPath function. There is
> simply no way to make this kind of rule fast in the context on an XML
> editor (while this is not a problem for a browser or for an XSLT
> processor).
Sigh.
>
> This has always been the case, even in XXE v3. By the way, this part
> of the code has not changed at all between v3 and v4.
>
> I did a very simple optimization which divided by 5 the load time of
> your document. Before the optimization it took 11mn30s (on my old,
> slow, desktop) to load your document. After this optimization, it took
> 2mn40s, which is still totally unacceptable.
Is this optimization you did available to us? That is, is there
something I can do in the configuration files?
>
> I've also implemented another strategy to handle id() in the context
> of CSS rules, and found it to be slower than current strategy (once
> optimized). So I gave up this alternative strategy.
>
> I'm really sorry but there is nothing more I can do for your problem.
> I can just recommend to keep the number of CSS rules making use of
> id() to the bare minimum.
OK, I hear you, although I am disappointed to hear it. Most, if not
all, of these usages of id() are an attempt to render element X using
the font properties of element Y, where an attribute on X is an IDREF to
element Y. Is there some other way to do this without using id()?
> ---
> PS: XLingPap.dtd references XLingPapPublisherStyleSheet.dtd, which
> does not exist. Your DTD module is called
> "XLingPapPublisherStylesheet.dtd" (notice the capitalization). Of
> course, this is not a problem on Windows, where the file system is
> case-insensitive.
Thank you so much for noticing this error on my part.
And thank you, too, for your quick analysis of the problem. We users
truly appreciate your great support.
--Andy
>
>
