Verify Rubinius compatibility

[artob]

Should be okay, but need to start running the specs against Rubinius 1.0 in addition to MRI 1.8/1.9 and JRuby.

[bhuga]

My locally compiled copy pegs my machine and takes literally hours to run the tests. Will investigate at some point.

[artob]

Probably a good idea to mention the (approximate) Rubinius and RDF.rb versions you tried, for anyone reading this issue later on...

[cpence]

Sure enough, this is still true (a year later), with rbx-2.0pre and RDF 0.3.4.1.

Something weird seems to be going on in ObjectSpaceCache. _id2ref hangs for a really long time, blocking up RDF. Perhaps defaulting to the WeakRef cache on Rubinius?

[cpence]

Sure enough -- hardwiring the cache to WeakRefCache in cache.rb fixes the problem.

Change over the cache selection code in cache.rb to be something like:

if RUBY_PLATFORM == 'java' || (defined?(RUBY_ENGINE) && RUBY_ENGINE == 'rbx')
  klass = WeakRefCache
else
  klass = ObjectSpaceCache

and all should be well.

[gkellogg]

Rubinius works with RDF.rb in 1.8 and 1.9 modes now (probably 2.0 too).