Re: [xml-dev] Packaging (was Re: [xml-dev] Interoperability)

[David Brownell <david-b@pacbell.net>]

David Megginson wrote:
> It makes sense because it's widely deployed and proven to work (as
> most of you know, Java's JAR format is zip-based).  The problem is
> that ZIP is non-streaming -- you have to download the entire zip file
> before you can start processing it, since the directory information is
> at the end.  Until we know what people are actually going to do with
> this stuff, it's hard to figure out the cost/benefit balance.

To pick a nit, illustrate one of your point, and raise a question  ... :)

    - The JAR manifest is directory info that's required to be at
      the beginning, specifically to avoid downloading the whole
      thing before processing it.  (It's extensible metadata; ZIP is
      short on certain kinds of metadata that's useful for stuff
      like digital signatures.)

    - I don't know how widely that's known or used, illustrating
      your implicit point about early estimates of cost/benefit ...

    - Maybe someone else knows whether that's actually relied
      on, except maybe inside the JDK's class loader.

I seem to recall a "jar:* URI syntax.  There might be good techie
reasons to use JAR instead of ZIP.  Even if it did give an initial
edge to implementations in Java, I know other platforms could
catch up quickly enough.

- Dave