object-storage: Initial unittest of DiskFile class

If we had this ahead of time, we could have avoided the errors that
were encountered leading to the fix-account-mapping fix (see
http://review.gluster.org/4222).

This represents 100% coverage of the DiskFile module, but the coverage
report says otherwise, unfortunately. That is because the put() method
invokes eventlets during the test run, and coverage is not able to
accurately track the coverage lines properly. If one comments out the
"tpool.execute()" line in DiskFile.put() the coverage report then
reports 100% for the DiskFile module.

Additionally, we changed DiskFile.put() in four ways that should not
change its behavior:

  1. Comments were added to explain various code paths and mark
     potential issues / fixes

  2. It no longer returns a boolean value, matching the behavior of
     swift.obj.server.DiskFile.put()

  3. It no longer logs a message when it detects a directory that
     already exists, instead is raises an exception

     We believe this is okay because we cannot find a code path that
     would lead to his condition. As a result, it makes it easier to
     test all the code paths in that routine.

  4. It no longer logs a message when create_dir_object() fails, since
     create_dir_object() raises an exception on failure only

     We also modified create_dir_object() to not return a boolean as a
     result of the above behavior.

Note that by implementing these tests up to this point we found three
code paths that would have failed if encountered due to missing
imports. We also made changes to the DiskFile module to make it a bit
easier to test, also eliminating an extra stat system call when
deleting directory objects.

Change-Id: I3286de83c1ec7c5e8d6cab9354e1c4397cee7497
BUG: 870589
Signed-off-by: Peter Portante <peter.portante@redhat.com>
Reviewed-on: http://review.gluster.org/4284
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Mohammed Junaid <junaid@redhat.com>

0 files changed, 0 insertions, 0 deletions