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Re: SAX and parallel processing

• To: Bob Foster <bob@o...>
• Subject: Re: SAX and parallel processing
• From: Alan Gutierrez <alan-xml-dev@e...>
• Date: Fri, 31 Dec 2004 19:59:21 -0500
• Cc: David Megginson <david.megginson@g...>, xml-dev@l...
• In-reply-to: <41D5F0D0.60501@o...>
• Mail-followup-to: Bob Foster <bob@o...>,David Megginson <david.megginson@g...>, xml-dev@l...
• References: <1104455192.3038.5.camel@borgia> <200412310131.52268.miles@m...> <1104460276.3038.23.camel@borgia> <41D4CC8C.1080200@o...> <1104465543.3038.28.camel@borgia> <20041231165744.GA20756@m...> <75cb920c04123110151af471f9@m...> <41D5DAD0.7000909@o...> <20041231234449.GA21911@m...> <41D5F0D0.60501@o...>
• User-agent: Mutt/1.4.1i

* Bob Foster <bob@o...> [2004-12-31 19:37]:
> Bob
> 
> Alan Gutierrez wrote:
> > * Bob Foster <bob@o...> [2004-12-31 18:03]:
> >>I have a question, though. What is the guaranteed lifetime of an object
> >>appearing in a SAX event, like an Attributes object, and any objects
> >>used to implement it? If, for example, Attributes were implemented as a
> >>collection of lightweight Attribute objects that were re-used for
> >>subsequent events, the event data could not be passed directly to
> >>parallel threads without copying it. (Or by joining at the end of every
> >>event, which would rather limit the parallelism.)
> >
> >
> >
> >     Xerces recycles Attributes structures for each call to
> >     startElement.

> >     In my library, I keep a stack of attribute structures. The
> >     attribute structures on the stack are recycled for each element
> >     depth, not actually popped and reallocated.

> Right. In order to process a SAX stream in parallel you have to
> copy the data in the stream, you can't just "forward" the events.
> You also have to instantiate a context for each event, including
> at least the namespaces in scope, the Location info. I didn't mean
> to imply this would be excessively expensive, just not as
> lightweight as serially processed SAX.

    Wasn't out to school you, so much as to relate my experience.

    Cheers.

--
Alan Gutierrez - alan@e...

• References:
  • Re: Re: Streaming XML (WAS: More on taming SAX (was Re: ANN: Amara XML Toolkit 0.9.0))
    • From: Uche Ogbuji <uche.ogbuji@f...>
  • Re: Re: Streaming XML (WAS: More on taming SAX (was Re: ANN: Amara XML Toolkit 0.9.0))
    • From: Miles Sabin <miles@m...>
  • Re: Re: Streaming XML (WAS: More on taming SAX (was Re: ANN: Amara XML Toolkit 0.9.0))
    • From: Uche Ogbuji <uche.ogbuji@f...>
  • Re: Re: Streaming XML (WAS: More on taming SAX (was Re: ANN: Amara XML Toolkit 0.9.0))
    • From: Bob Foster <bob@o...>
  • Re: Re: Streaming XML (WAS: More on taming SAX (was Re: ANN: Amara XML Toolkit 0.9.0))
    • From: Uche Ogbuji <uche.ogbuji@f...>
  • Re: Re: Streaming XML (WAS: More on taming SAX (was Re: ANN: Amara XML Toolkit 0.9.0))
    • From: Alan Gutierrez <alan-xml-dev@e...>
  • SAX and parallel processing
    • From: David Megginson <david.megginson@g...>
  • Re: SAX and parallel processing
    • From: Bob Foster <bob@o...>
  • Re: SAX and parallel processing
    • From: Alan Gutierrez <alan-xml-dev@e...>
  • Re: SAX and parallel processing
    • From: Bob Foster <bob@o...>

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