Re: [xri] XRD element order

[Will Norris <will@willnorris.com>]

On Jun 24, 2009, at 12:27 PM, Will Norris wrote:

> But really, do we think this is going to be a real problem?  How  
> large of a document can even the most constrained SAX parsers  
> handle?  Several KB easily, if not several MB.  And how much good  
> will the above optimizations actually do?  I suspect that most  
> parsers will just parse all elements regardless.

To clarify this point...  SAX parsers, by design, will parse all the  
elements we're talking about here.  The optimization with placing  
"expires" early in the document is a little different because it does  
allow the parser to bail out entirely.  But with these extension  
elements, the parser is going to walk over everything regardless, so  
there is no real limit to the size of document it can handle.  The  
limitation comes with what the parser is actually doing with the  
data.  Is it converting those XML elements into some kind of internal  
data structures?  If the parser is able to know that it can ignore the  
elemnt and simply walk over it, then that's where the optimization  
comes in.

And I'll be really up front in saying that I only have a theoretical  
knowledge of SAX Parsers.  I know how they work and generally how to  
optimize for them, but all of my personal experience has been with DOM.

-will