Compressing SimpleLibrary with GZIP

[Aleksey Shipilev]

On 03/14/2012 12:07 AM, Alan Bateman wrote:
> On 13/03/2012 17:26, Aleksey Shipilev wrote:
> The jmod create command has the -z (or --enable-compression) option to
> enable compression on the module contents. At this point it's for the
> module classes only.

Yes, I noticed that option. It has no effects on my large multimodule
tests which have hundreds of modules, metadata dominates there. For the
reference, this is the library with "just" 500 modules, and 1 simple
class per module:

$ du -sk library-c500-d500*
  1266020	library-c500-d500.BASELINE
  107152	library-c500-d500.GZIP

How about that!

Is SimpleLibrary considered to be prototype? If so, then enabling
compression aids me to do more experiments with it, when I don't have to
burn my disks reading and writing gigabytes of metadata. Yes, I've been
considering using squashfs to fit all these libraries on my machine, but
it seems less appealing than changing a few lines in Jigsaw code.

> Clearly if we were to continue with the existing configuration file then
> compression should be considered too but that all should change soon.
> The loading of the config file is a problem for startup performance too.

Sure, that opens up a number of questions. Is there timeline for these
changes? Is the binary format for config settled on? Is the internal API
for Library more or less stable? If so, we can embark on implementing
low-footprint high-performance Library for Jigsaw at this point, leaving
SimpleLibrary alone as prototype.

-Aleksey.