Re: [Vtd-xml-users] Random Access Proposal (take 2)

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Mark, my implementation has some bug... it doesn't really work, but
just let me know if the API is ok to you.<br>
<br>
We can iron-out bugs latter, with Jimmy help perhaps :-)<br>
<br>
You can create a SimpleContext, witch holds a position, with:<br>
<br>
SimpleContext ctx = new SimpleContext(null);<br>
//starts as an empty context<br>
<br>
or<br>
<br>
SimpleContext ctx = new SimpleContext(int size);<br>
// starts with given nodes capacity, so reallocation can be minimized
during reuse<br>
<br>
and you can use the object to hold and retrieve positions with:<br>
<br>
navigator.setCtxFromNav(ctx);<br>
//holds current position in this context object<br>
<br>
and<br>
<br>
navigator.setNavFromCtx(ctx);<br>
//sets navigator pointers from this context object<br>
<br>
<br>
The object itself has little storage requirements, only a small integer
array, so you can create thousands and still live happy.<br>
<br>
They are also reusable, to minimize garbage collection just in case
your algoritm wants to reuse them.<br>
<br>
Does this sound ok for you, Mark?<br>
<br>
<br>
<br>
Mark Swanson wrote:
<blockquote cite="mid...@Sc..." type="cite">
  <pre wrap="">Rodrigo Cunha wrote:
  </pre>
  <blockquote type="cite">
    <pre wrap="">I understand NodeRecorder was not intended to be kept in large numbers, 
but I think that should exactly be the idea of a random access API: a 
lightweight way of keeping a bunch of bookmarks in the datastructure the 
programmer wants, not in the structure we want, or something...

Your API is nice for somewhat serial processing, not for true random 
access, using pre-build hash tables, for example, or trees, or whatever. 
I could built a wrapper around NodeRecorder implementing a simplier API, 
but that would be really clumsy.

My API, while incomplete, is much more simple, and flexible also... it's 
also rather light. I would like to learn about other opinions on the 
subject, since we are probably both too used to our way of doing things 
to be impartial.
    </pre>
  </blockquote>
  <pre wrap=""><!---->
It would be most helpful to me if I could index arbitrary element 
indexes and start and XPath query from one of these indexes. I would 
cache these indexes in a Map with key: some unique ID, value: some sort 
of vtd-xml node index.

For most of the applications I use XML for, this would be the only way 
to get acceptable performance. Ultimately, without this I would not be 
able to consider using vtd-xml for these apps and I would be forced to 
use an xml - Object mapping tool.

I've been using and helping maintain/fix a number of XML - Object 
mapping tools over the years. It's been an interesting area of study for 
me. Please free me from the insufferable weight of those chains :-)

Cheers.

  </pre>
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