object-storage: use temp file optimization

A file name '.<FILENAME>.<RANDOM>' will hash to the same GlusterFS node
as a file named '<FILENAME>', thus avoiding creation/deletion of linkfiles on a rename.

This is part of the work needed to address BZ 876660
(https://bugzilla.redhat.com/show_bug.cgi?id=876660).

Change-Id: I6f18c14b8eaa7a35c96f7e455ef3a19bee7dbde5
BUG: 876660
Signed-off-by: Mohammed Junaid <junaid@redhat.com>
Reviewed-on: http://review.gluster.org/4325
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Reviewed-by: Peter Portante <pportant@redhat.com>

2 files changed, 32 insertions, 16 deletions

diff --git a/ufo/gluster/swift/common/DiskFile.py b/ufo/gluster/swift/common/DiskFile.py
index 62f98103762..a25ba806575 100644
--- a/ufo/gluster/swift/common/DiskFile.py
+++ b/ufo/gluster/swift/common/DiskFile.py
@@ -15,8 +15,9 @@
 
 import os
 import errno
+import random
+from hashlib import md5
 from eventlet import tpool
-from tempfile import mkstemp
 from contextlib import contextmanager
 from swift.common.utils import normalize_timestamp, renamer
 from swift.common.exceptions import DiskFileNotExist
@@ -102,7 +103,6 @@ class Gluster_DiskFile(DiskFile):
         self.device_path = os.path.join(path, device)
         self._container_path = os.path.join(path, device, container)
         self._is_dir = False
-        self.tmpdir = os.path.join(path, device, 'tmp')
         self.tmppath = None
         self.logger = logger
         self.metadata = {}
@@ -309,9 +309,24 @@ class Gluster_DiskFile(DiskFile):
     def mkstemp(self):
         """Contextmanager to make a temporary file."""
 
-        if not os.path.exists(self.tmpdir):
-            mkdirs(self.tmpdir)
-        fd, self.tmppath = mkstemp(dir=self.tmpdir)
+        # Creating intermidiate directories and corresponding metadata.
+        # For optimization, check if the subdirectory already exists,
+        # if exists, then it means that it also has its metadata.
+        # Not checking for container, since the container should already
+        # exist for the call to come here.
+        if not os.path.exists(self.datadir):
+            path = self._container_path
+            subdir_list = self._obj_path.split(os.path.sep)
+            for i in range(len(subdir_list)):
+                path = os.path.join(path, subdir_list[i]);
+                if not os.path.exists(path):
+                    self._create_dir_object(path)
+
+        tmpfile = '.' + self._obj + '.' + md5(self._obj + \
+                  str(random.random())).hexdigest()
+
+        self.tmppath = os.path.join(self.datadir, tmpfile)
+        fd = os.open(self.tmppath, os.O_RDWR | os.O_CREAT | os.O_EXCL)
         try:
             yield fd
         finally:
diff --git a/ufo/test/unit/common/test_diskfile.py b/ufo/test/unit/common/test_diskfile.py
index 7583fd7fa5d..fb0dc3e16d5 100644
--- a/ufo/test/unit/common/test_diskfile.py
+++ b/ufo/test/unit/common/test_diskfile.py
@@ -108,7 +108,6 @@ class TestDiskFile(unittest.TestCase):
         assert gdf.datadir == "/tmp/foo/vol0/bar"
         assert gdf.device_path == "/tmp/foo/vol0"
         assert gdf._container_path == "/tmp/foo/vol0/bar"
-        assert gdf.tmpdir == "/tmp/foo/vol0/tmp"
         assert gdf.disk_chunk_size == 65536
         assert gdf.iter_hook == None
         assert gdf.logger == self.lg
@@ -134,7 +133,6 @@ class TestDiskFile(unittest.TestCase):
         assert gdf.name == "bar/b/a"
         assert gdf.datadir == "/tmp/foo/vol0/bar/b/a"
         assert gdf.device_path == "/tmp/foo/vol0"
-        assert gdf.tmpdir == "/tmp/foo/vol0/tmp"
 
     def test_constructor_no_metadata(self):
         td = tempfile.mkdtemp()
@@ -848,10 +846,11 @@ class TestDiskFile(unittest.TestCase):
                                    "dir/z", self.lg)
             saved_tmppath = ''
             with gdf.mkstemp() as fd:
-                assert gdf.tmpdir == os.path.join(td, "vol0", "tmp")
-                assert os.path.isdir(gdf.tmpdir)
+                assert gdf.datadir == os.path.join(td, "vol0", "bar", "dir")
+                assert os.path.isdir(gdf.datadir)
                 saved_tmppath = gdf.tmppath
-                assert os.path.dirname(saved_tmppath) == gdf.tmpdir
+                assert os.path.dirname(saved_tmppath) == gdf.datadir
+                assert os.path.basename(saved_tmppath)[:3] == '.z.'
                 assert os.path.exists(saved_tmppath)
                 os.write(fd, "123")
             assert not os.path.exists(saved_tmppath)
@@ -867,10 +866,11 @@ class TestDiskFile(unittest.TestCase):
                                    "dir/z", self.lg)
             saved_tmppath = ''
             with gdf.mkstemp() as fd:
-                assert gdf.tmpdir == os.path.join(td, "vol0", "tmp")
-                assert os.path.isdir(gdf.tmpdir)
+                assert gdf.datadir == os.path.join(td, "vol0", "bar", "dir")
+                assert os.path.isdir(gdf.datadir)
                 saved_tmppath = gdf.tmppath
-                assert os.path.dirname(saved_tmppath) == gdf.tmpdir
+                assert os.path.dirname(saved_tmppath) == gdf.datadir
+                assert os.path.basename(saved_tmppath)[:3] == '.z.'
                 assert os.path.exists(saved_tmppath)
                 os.write(fd, "123")
                 os.close(fd)
@@ -887,10 +887,11 @@ class TestDiskFile(unittest.TestCase):
                                    "dir/z", self.lg)
             saved_tmppath = ''
             with gdf.mkstemp() as fd:
-                assert gdf.tmpdir == os.path.join(td, "vol0", "tmp")
-                assert os.path.isdir(gdf.tmpdir)
+                assert gdf.datadir == os.path.join(td, "vol0", "bar", "dir")
+                assert os.path.isdir(gdf.datadir)
                 saved_tmppath = gdf.tmppath
-                assert os.path.dirname(saved_tmppath) == gdf.tmpdir
+                assert os.path.dirname(saved_tmppath) == gdf.datadir
+                assert os.path.basename(saved_tmppath)[:3] == '.z.'
                 assert os.path.exists(saved_tmppath)
                 os.write(fd, "123")
                 os.unlink(saved_tmppath)