Re: [Vtd-xml-users] update-operation impact, if any?

[Sun, V. <vs...@am...>]

I see.=20
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Our use case is a xml processing pipeline, each stage will modify the
document then send it down to the next stage for further processing...
if I understand your comments correctly, this means each stage will have
to produce a new byte[] and NVDNav in order for the next stage to see
and navigate the whole document...
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We are currently using a Dom tree and just keep adding new data to the
tree and pass the tree through the pipeline. Sure it is slow (that's why
we are looking for alternative), but intuitively thinking, it should
still be more efficient for partial updates than recreate the whole
document for each stage ... am I missing something?
=20
--------------------------
Cheers,
Vanessa
=20

________________________________

From: Jimmy Zhang [mailto:cra...@co...]=20
Sent: Sunday, July 01, 2007 11:14 AM
To: Sun, Vanessa; vtd...@li...
Subject: Re: [Vtd-xml-users] update-operation impact, if any?


Does XMLModifier directly manipulating the underlying byte[]?=20
XMLModifier does *not* directly overwrite the underlying bytes...=20
it will apply change and output *new* XML data into OutputStream...
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How does it handle inserting new data fragment?=20
if you insert new data fragment, you just have to navigate the cursor to
the right spot in the XML document and drop it in
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create a new memory block to combine both of them? or just track the new
block with the token?=20
yes, that is right ,
except you don't explicitly create new memory block, instead you create
an outputStream (e.g. ByteArrayOutputStream)
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Is there a performance benchmark on update operation comparison with the
other implementation?
 http://vtd-xml.sourceforge.net/benchmark1.html update+xpath+indexing,
so update is part of it
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Can we associate multiple VTDNav with the VTDGen? Regardless, how will
the update operation impact the existing VTDNav ? (the currentIdnex for
example)
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You can using VTDGen to create multiple VTDNav, think VTDGEn as a DOM
parser, VTDNav as a DOM tree..
Has not effect on update, as update is associated with VTDNav, not
VTDGen...
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How will these newly inserted fragments impact the overall navigation
performance?=20
=20
No effect, since inserted fragement are not really inserted, XMLModifier
only records the insertion, new XML is created only when you ask
XMLModifier to output new XML
=20
How does the update operation impact the existing bookmarks?=20
=20
No effect, as the update operation's effect isn't immediate
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	----- Original Message -----=20
	From: Sun, Vanessa <mailto:vs...@am...> =20
	To: vtd...@li...=20
	Sent: Saturday, June 30, 2007 10:26 PM
	Subject: [Vtd-xml-users] update-operation impact, if any?
=09
=09
	Wondering what is frequent update/insert impact for vtd-xml :

	*=09
		Does XMLModifier directly manipulating the underlying
byte[]? How does it handle inserting new data fragment? create a new
memory block to combine both of them? or just track the new block with
the token? Is there a performance benchmark on update operation
comparison with the other implementation?
	*=09
		How will these newly inserted fragments impact the
overall navigation performance?=20
	*=09
		How does the update operation impact the existing
bookmarks?=20
	*=09
		Can we associate multiple VTDNav with the VTDGen?
Regardless, how will the update operation impact the existing VTDNav ?
(the currentIdnex for example)

	Thanks.
	=20
	--------------------------
	Cheers,
	Vanessa
	=20

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________________________________


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