RE: [xml] XML library evaluation (fwd)

["Igor Zlatkovic" <izlatkovic daenet de>]

Hi there,

If that intrudes less than too far into the confidential space, I would
know which company did this evaluation?


> -----Original Message-----
> From: Dan Ellis [mailto:dan isvara net] 
> Sent: 13 June 2002 16:18
> To: xml gnome org
> Subject: [xml] XML library evaluation (fwd)
>
>
> The company I work for has been developing C++ software using 
> the libxml2
> library. However, due to memory allocation problems within 
> the library it
> has been decided to drop libxml2 in favour of Xerces. I've 
> suggested that
> they bring these issues up here to see if they're known, and 
> if there are
> any solutions (either existing, or being worked on). This hasn't been
> done, so I'm forwarding some information regarding the evaluation. Are
> these known issues? Can anything be done about them, and if 
> so, will they
> be?
>
> ---------- Forwarded message ----------
>
> [snip]
>
> Libxml2 evaluation
> The libxml2 library displayed a lot of different errors, both crashes,
> where un-initialised data, null pointers and data that had 
> already been
> freed was accessed. Secondly there here a lot of memory leaks 
> that needed
> to be fixed.
>
> But the main concern was that the library is written in C and is not
> designed to return an "Out of memory" error code from the 
> calls into the
> library. Instead a variety of different behaviour was seen:
>
> 1.) Quietly recover, where the processing would simply 
> continue after the
> allocation failure, but some data would be missing in the XML 
> tree that it
> was building. Another problem was that any error, during the libraries
> initialisation would not be reported and hence the whole 
> library would not
> work correctly, for example some character handling functions 
> might not be
> present.
>
> 2.) Return an error code, which would not be distinguishable 
> from any other
> error, for example when parsing a document, it is not possible to
> distinguish a parse error from a memory allocation error.
>
> [snip]
>
> Conclusion
> On balance it seems, barring any problems that A might discover, that
> the following picture emerges:
>
> * Libxml2 - It's general lack of safety and lack of "out of 
> memory" return
> codes make this library unacceptable.
> * Xerces - While it has some disadvantages, mainly it's side 
> and lacking
> some features that we would want, most notably serialization 
> as part of the
> library and the ability to validate the DOM tree, it is 
> overall the safest
> option and has XMLSchema support, which none of the other do.
>
> [snip]
>
> -- 
> Dan Ellis <dan isvara net>
>
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