object-storage: only open file when requested

Only open a file when the caller of the constructor indicates that it
expects to have a file pointer to access in the "fp" field.

Found by Junaid during review http://review.gluster.org/4284, Patch
set 6.

We also bump the version number to mark a line in the set of changes
we want to perform a mini release with to double check for performance
regressions.

Change-Id: I13cf336bb519088890192ee111f4ece85a5982c4
BUG: 886730
Signed-off-by: Peter Portante <peter.portante@redhat.com>
Reviewed-on: http://review.gluster.org/4303
Reviewed-by: Mohammed Junaid <junaid@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/ufo/gluster/swift/common/DiskFile.py b/ufo/gluster/swift/common/DiskFile.py
index 8522295483d..62f98103762 100644
--- a/ufo/gluster/swift/common/DiskFile.py
+++ b/ufo/gluster/swift/common/DiskFile.py
@@ -137,9 +137,13 @@ class Gluster_DiskFile(DiskFile):
         if os.path.isdir(data_file):
             self._is_dir = True
         else:
-            self.fp = do_open(data_file, 'rb')
-            if not keep_data_fp:
-                self.close(verify_file=False)
+            if keep_data_fp:
+                # The caller has an assumption that the "fp" field of this
+                # object is an file object if keep_data_fp is set. However,
+                # this implementation of the DiskFile object does not need to
+                # open the file for internal operations. So if the caller
+                # requests it, we'll just open the file for them.
+                self.fp = do_open(data_file, 'rb')
 
     def close(self, verify_file=True):
         """