Ah, my mistake, I could not quite detect what you meant from your original
post.

I noticed the sentence, "Do we really need to "count" more than 2^32 nodes
in a document, or be able to index into more than 2^32 of character data?"
and thereby became concerned that we would be placing a 4GB (or whatever)
size limit on instance documents. Based on what I understand you to be
saying now, I can agree 32 bits is more reasonable for the purposes you
listed.

Not understanding the code too well, I feel the need to ask what happens if
these 32-bit size values are also used in the code for the memory managers?
Could that limit the size of DOM tree that could be used when writing a new
XML document to an unreasonably small value for larger instance documents?

--Matt

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Sent: Friday, June 10, 2005 2:10 PM
To: [email protected]
Subject: RE: Need for XMLSize_t?


> My enterprise works with very large instance documents that are rich in
> tags. Currently some of our large documents are 750 MB and are growing 
fast
> as more data is added to the XML feeds and more users subscribe to our
> services.
> 
> If we went over 2/4/whatever GB limit that these 32-bit types impose, 
that
> would be very bad. Therefore I advocate making sure a library compiled 
as
> 64-bit shares the same traditional large file safety that people have 
come
> to expect in other 64-bit libraries. If this convention is not followed,
> what is the point of having 64-bit Xerces in the first place?

It's not as simple as that.  We are talking about counts of nodes, not 
sizes of nodes, or the amount of memory that's addressable.  For example, 
it's roughly:

4,294,967,296 nodes per document
4,294,967,296 characters per string value (8,589,934,592 bytes)
4,294,967,296 nodes per node list

etc.

I think you get the idea.  Even with 64-bit addressing, the amount of 
memory consumed by a document that went over these limits would be huge. I 
think it's also worth mentioning that, if we go to 64-bit values 
everywhere, every document will pay the price in potentially overhead for 
the few documents that manage to hit these limits.  Of course, it's always 
possible to redefine the typedef to be a 64-bit value, if you should need 
to.  That's why typedefs are a "good thing" and we should carefully 
examine the use of XMLSize_t before we make any change.

Dave
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