[tahoe-lafs-trac-stream] [tahoe-lafs] #393: mutable: implement MDMF

[tahoe-lafs]

#393: mutable: implement MDMF
-------------------------+-------------------------------------------------
     Reporter:  warner   |      Owner:  zooko
         Type:           |     Status:  new
  enhancement            |  Milestone:  1.9.0
     Priority:  major    |    Version:  1.0.0
    Component:  code-    |   Keywords:  newcaps performance random-access
  mutable                |  privacy gsoc mdmf mutable backward-
   Resolution:           |  compatibility forward-compatibility review-
Launchpad Bug:           |  needed
-------------------------+-------------------------------------------------

Comment (by davidsarah):

 I added the following tests to {{{test_mutable.py}}}, to try to catch
 fencepost errors with zero-length reads. They both fail, although I think
 they're correct:
 {{{

     def test_partial_read_zero_length_at_start(self):
         d = self.mdmf_node.get_best_readable_version()
         c = consumer.MemoryConsumer()
         d.addCallback(lambda version:
             version.read(c, 0, 0))
         d.addCallback(lambda ignored:
             self.failUnlessEqual("", "".join(c.chunks)))
         return d

     def test_partial_read_zero_length_at_segment_boundary(self):
         d = self.mdmf_node.get_best_readable_version()
         c = consumer.MemoryConsumer()
         offset = mathutil.next_multiple(128 * 1024, 3)
         d.addCallback(lambda version:
             version.read(c, offset, 0))
         d.addCallback(lambda ignored:
             self.failUnlessEqual("", "".join(c.chunks)))
         return d
 }}}

 Also, the test named {{{test_partial_read_ending_on_segment_boundary}}} is
 actually testing a read ending one byte after a segment boundary. I don't
 know whether that's intentional; if it is then the test should be renamed.

-- 
Ticket URL: <http://tahoe-lafs.org/trac/tahoe-lafs/ticket/393#comment:142>
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