TransformSnapshotImpl - is it any use?

[Brian Minchau <mi...@ca.ibm.com>]

I'm working on merging the serializers of Xalan-J interpretive and XSLTC,
and I can't find a use for TransformSnapshotImpl in the
org.apache.xalan.transformer package.

Is anyone using it?  Does anyone know what its purpose is?

It seems to be saving and restoring the state of the transformation
(including the serializer).  But the save/restore doesn't seem to be
complete so I'm wondering if it is being used.  For example these fields of
the ResultTreeHandler are saved and restored:
      m_eventCount
      m_nsSupport
      m_nsContextPushed
The m_eventCount field is handled, and it comes from QueuedEvents class
that ResultTreeHandler inherits from, but there are plenty of other fields
in QueuedEvents that are not saved and restored, such as:
      m_name
      m_url
      m_elemIsPending
      ...

Any help in understanding what this class is supposed to save and restore,
or why it exists would be appreciated.



Brian Minchau
XSLT Development, IBM Toronto
e-mail:        minchau@ca.ibm.com

Re: TransformSnapshotImpl - is it any use?

[Joseph Kesselman <ke...@us.ibm.com>]

TransformSnapshotImpl implements TransformSnapshot. These are currently 
referenced in the TransformerImpl class's getSnapshot(), 
executeFromSnapshot(), and resetToStylesheet() methods. 

As far as I can tell (I'm not looking at the main-line code right now), 
those are not currently invoked within Xalan and aren't part of the 
published Transformer API. 

It's possible that someone has been using them for tooling purposes; we 
should check carefully before deciding whether to make them work or make 
them gone.

______________________________________
Joe Kesselman, IBM Next-Generation Web Technologies: XML, XSL and more. 
"may'ron DaroQbe'chugh vaj bIrIQbej"  ("Put down the squeezebox and nobody 
gets hurt.")