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Re: [Vtd-xml-users] update-operation impact, if any?
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From: Jimmy Z. <cra...@co...> - 2007-07-02 01:11:12
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It is not much different from DOM, albeit VTD-XML's more efficient...=20 when you send DOM downstream, still need to serialize...=20 for VTD-XML, you just call XMLModifier's output()... The following stage will still need to parse the incoming XML ... so you have to=20 1. parse 2. add changes 3. generate output whether using DOM or VTD-XML... where is the difference? ----- Original Message -----=20 From: Sun, Vanessa=20 To: Jimmy Zhang ; vtd...@li...=20 Sent: Sunday, July 01, 2007 4:44 PM Subject: RE: [Vtd-xml-users] update-operation impact, if any? I see.=20 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... 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? -------------------------- Cheers, Vanessa -------------------------------------------------------------------------= ----- 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... 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 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) 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 Can we associate multiple VTDNav with the VTDGen? Regardless, how will = the update operation impact the existing VTDNav ? (the currentIdnex for = example) 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... How will these newly inserted fragments impact the overall navigation = performance?=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 How does the update operation impact the existing bookmarks?=20 No effect, as the update operation's effect isn't immediate ----- Original Message -----=20 From: Sun, Vanessa=20 To: vtd...@li...=20 Sent: Saturday, June 30, 2007 10:26 PM Subject: [Vtd-xml-users] update-operation impact, if any? Wondering what is frequent update/insert impact for vtd-xml : a.. 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? b.. How will these newly inserted fragments impact the overall = navigation performance?=20 c.. How does the update operation impact the existing bookmarks?=20 d.. Can we associate multiple VTDNav with the VTDGen? Regardless, = how will the update operation impact the existing VTDNav ? (the = currentIdnex for example) Thanks. -------------------------- Cheers, Vanessa -------------------------------------------------------------------------= --- = -------------------------------------------------------------------------= This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/=20 -------------------------------------------------------------------------= --- _______________________________________________ Vtd-xml-users mailing list Vtd...@li... https://lists.sourceforge.net/lists/listinfo/vtd-xml-users |
