[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Does SAX make sense?

• To: <xml-dev@l...>
• Subject: Does SAX make sense?
• From: "Rick Jelliffe" <ricko@a...>
• Date: Sat, 19 Apr 2003 17:38:42 +1000
• References: <E196lKL-0001Uj-00@b...>

I am idly wondering whether unpooled steaming Java APIs of XML documents (e.g. SAX)
really make as much sense as we might like them to.

It strikes me that there are two factors that undermine the benefits of streaming processing:

* XML documents are rarely smaller than memory
* Java implementations typically only garbage collect when they get "near" 
  to filling their heaps.

These two things conspire to make it that, for the lion's share of documents,
by the time the SAX stream is finished, all the SAX events will be still
in memory, though perhaps unreachable. If they are in memory, why not
make them available?

That being the case, it seems that simple streaming such as SAX provides
don't make sense.  They would be better to either

* have the SAX stream kept cached for the lifetime of the document
(or have some kind of weak reference perhaps) since they are in memory 
anyway (though unreachable), allowing backward-looking XPaths; or

* requiring SAX clients return events to a pool (which would reduce 
memory use).

Does that sound right to anyone?


Cheers
Rick Jelliffe

• Follow-Ups:
  • Re: Does SAX make sense?
    • From: "Jeff Rafter" <jeffrafter@d...>
  • Re: Does SAX make sense?
    • From: Michael Brennan <mpbrennan@e...>
  • Re: Does SAX make sense?
    • From: Joe English <jenglish@f...>
  • Re: Does SAX make sense?
    • From: "Simon St.Laurent" <simonstl@s...>
  • re: Does SAX make sense?
    • From: David Megginson <david@m...>
  • Re: Does SAX make sense?
    • From: Daniel Veillard <veillard@r...>
  • RE: Does SAX make sense?
    • From: "Michael Kay" <michael.h.kay@n...>
  • Re: Does SAX make sense?
    • From: james anderson <james.anderson@s...>

• References:
  • Re: ANN: White Paper - "Using OWL to Avoid Syntactic Rigor Mortis"
    • From: Uche Ogbuji <uche.ogbuji@f...>

• Prev by Date: Re: ANN: White Paper - "Using OWL to Avoid Syntactic Rigor Mortis"
• Next by Date: Re: What is XML's appropriate place in an office suite?
• Previous by thread: Re: ANN: White Paper - "Using OWL to Avoid Syntactic Rigor Mortis"
• Next by thread: Re: Does SAX make sense?
• Index(es):
  • Date
  • Thread