[tor-bugs] #16424 [metrics-lib]: Support parsing of .xz compressed tarballs

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#16424: Support parsing of .xz compressed tarballs
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     Reporter:  karsten      |      Owner:  karsten
         Type:  enhancement  |     Status:  needs_revision
     Priority:  normal       |  Milestone:
    Component:  metrics-lib  |    Version:
   Resolution:               |   Keywords:
Actual Points:               |  Parent ID:
       Points:               |
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Comment (by karsten):

 Regarding importing dependent jars into `descriptor.jar`, I can see pros
 and cons.  Right now, we're producing a minimal `descriptor.jar` file and
 requiring applications to also add certain versions of other libraries
 into their classpath.  With your change we'd produce a larger
 `descriptor.jar` that comes with the jars it needs, at the risk of
 producing uncertain behavior if applications use older or newer versions
 of those libraries in their classpaths.  However, we don't have to solve
 this in this ticket, which is why I'd rather want to move this discussion
 to its own ticket.  Sound okay?

 With respect to your observation of blocking until parsing is complete,
 please take a look at `DescriptorReader.setMaxDescriptorFilesInQueue` and
 try setting it to a larger value.  It's actually supposed to be a feature
 not to load and parse too many descriptors if the application doesn't
 process them.  It's quite possible that there's a smarter way to achieve
 this.  That discussion would go into a new ticket, too.

 Let me summarize:
  - We should merge your patch without the 1.7 upgrade and without
 `<zipgroupfileset/>`.  Want to undo these changes?
  - We should open two or three new tickets:
    - Upgrade to Java 1.7,
    - Include dependent jars in `descriptor.jar`, and
    - Find smarter metric than number of descriptor files to block loading
 and parsing until descriptors have been processed.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/16424#comment:11>
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