Re: How to specify OPAQUE data

Stefan Haustein <[email protected]> Wed, 09 Apr 2003 14:14:47 +0200
Newsgroups gmane.comp.java.enhydra.kxml
Message-ID <[email protected]>
>         Can you please tell me what do I need to do to specify that some 
> of the data specified in the XML file that I want to encode should be 
> encoded as OPAQUE data. 

I do not know how to specify OPAQUE data in XML.
To my understanding WBXML provides some extensions that do not have an 
XML counterpart.

> Also, I modified WbxmlParser.java and 
> WbxmlWriter.java to encode string entities, such as a string 
> "http://www.google.com" will be encoded as HTTP_TOKEN WWW_TOKEN "google" 
> COM_TOKEN, something like this, and I wonder if you would not mind 
> looking over the changes that I have done and tell me what you think.

I assume you build a kind of "word table"? One problem with this 
approach may be that one does not know in advance whether a word shows 
up again in the text, and adding a word to the table plus the reference 
to the table consumes more space. Did you perform some experiments to 
test whether the compression is actually better?

> Also, why setTagTable(), setAttrStartTable(), and setAttrValueTable() 
> method in WbxmlParser.java and WbxmlWriter.java were implemented 
> differently. Thanks in advance.

In the parser, one needs to look up the text for a code value, and in 
the serializer, one needs to look up the code for a text fragment, thus, 
the tables are set up differently, optimized for the different kinds of 
access.

Best,
Stefan