module file reading/writing

[Sean Mullan]

Hi Dalibor,

I'm wondering why you would want to extract a module-file? Wouldn't you always 
want to install to a library directly from a module-file?

I'm also thinking about when signatures should be verified. Once you extract the 
module, the signature can no longer be subsequently verified (since it is over 
the compressed content). However, it seems that signature verification (and 
other security validation logic such as certificate validation, policy checks) 
should really be done as part of the install phase.

Can you describe what the difference is between extract and install, and why you 
need both?

Thanks,
Sean

Dalibor Topic wrote:
> Hi,
> 
> I've pushed an initial implementation of the reader/writer code
> for the module format specified in [1].
> 
> It adds a new 'jmod' verb to jpkg. So if you'd want to turn a 'hello'
> module at version 0.1 on disk into a jmod file, you'd do this:
> 
> jpkg -m hello jmod hello
> 
> and get a hello at 0.1.jmod file.
> 
> If the module has resources, etc you can tell jpkg about the
> directories to add to a module using:
> 
> -r dir for resources
> --natlib dir for native libraries
> --natcmd dir for native commands
> --config dir for configuration data
> 
> In addition you can specify a directory to create the jmod file
> into using -d dir option.
> 
> Within each module file section, regular files are gzipped, while
> classes are pack200 compressed.
> 
> In order to extract a jmod file, you can use the jmod tool, for
> example
> 
> jmod extract hello at 0.1.jmod
> 
> will extract the module file into the 'hello' directory. Sections
> other then classes are extracted into subdirectories.
> 
> There is an initial set of module format tests, with more to come,
> as I hack on improving the code. Please try it out, and tell me
> if it works, breaks, etc.
> 
> cheers,
> dalibor topic
> 
> [1] http://cr.openjdk.java.net/~mr/jigsaw/notes/module-file-format/