RFR 8213031: (zipfs) Add support for POSIX file permissions

[Alan Bateman]

On 14/01/2019 07:42, Langer, Christoph wrote:
>
> Hi Lance,
>
> I was not aware of JDK-8182117 and by its description it does not fit 
> exactly to the updates to jdk.zipfs module documentation that I 
> propose. However, yes, it is probably a bit more natural to include 
> that part in a potential patch for JDK-8182117. So, feel free to take 
> this over into your work. Seeing how things are going with this POSIX 
> permission topic, I’m sure you’ll be done with a patch for 8182117 
> much earlier than me ��.
>
>
The history on zipfs is that it started out as an example/demo provider 
to demonstrate the service provider mechanism. The implementation 
improved over time and also started to get some traction and users, e.g. 
with javac. So it "promoted" from a demo to a supported provider and has 
been maintained as such for a few releases. Prior to modules there 
wasn't anywhere to document it. In its example state we had a docs page 
that documents the "encoding" and "create" settings but that's not the 
right place now. So JDK-8182117 is just about expanding the javadoc in 
module-info.java from what used to be a separate document. I suspect it 
will also need a section showing how to create a file system from a URI 
or by opening a file as a file system.

The POSIX file permissions is another matter of course as that ends up 
trying to use APIs in ways that they were not intended. APIs such as 
BasicFileAttributes allow for some optionally with custom providers that 
aren't support all features but PosixFileAttributes does not allow for 
this. I plan to find time this week to suggest some options to explore 
that would avoid trying to twist existing APIs in ways that they weren't 
intended. Once we converge on an approach then the module-info will be 
the right place to document how optionally permissions can be accessed.

-Alan