Fix redundant stat in account and container server

Multiple stat() calls were made while serving GET requests for container
and account. This removes those calls and can be easily verified using
strace.

There is room for further refactoring of code to simplify it. This will
be addressed as a separate change to keep things simple in this patch.

Change-Id: Ief457ff869c58519e9dbeb4ef13797185f536673
Signed-off-by: Prashanth Pai <ppai@redhat.com>
Reviewed-on: http://review.gluster.org/14543
Reviewed-by: Thiago da Silva <thiago@redhat.com>
Tested-by: Thiago da Silva <thiago@redhat.com>

1 files changed, 10 insertions, 4 deletions

diff --git a/gluster/swift/common/DiskDir.py b/gluster/swift/common/DiskDir.py
index 204ae1d..4f4a2ef 100644
--- a/gluster/swift/common/DiskDir.py
+++ b/gluster/swift/common/DiskDir.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import os
+import stat
 import errno
 
 from gluster.swift.common.fs_utils import dir_empty, mkdirs, do_chown, \
@@ -177,7 +178,7 @@ class DiskCommon(object):
         self.logger = logger
         self.account = account
         self.datadir = os.path.join(root, drive)
-        self._dir_exists = None
+        self._dir_exists = False
 
         # nthread=0 is intentional. This ensures that no green pool is
         # used. Call to force_run_in_thread() will ensure that the method
@@ -186,7 +187,7 @@ class DiskCommon(object):
         self.threadpool = ThreadPool(nthreads=0)
 
     def _dir_exists_read_metadata(self):
-        self._dir_exists = do_exists(self.datadir)
+        self._dir_exists = os.path.isdir(self.datadir)
         if self._dir_exists:
             try:
                 self.metadata = _read_metadata(self.datadir)
@@ -199,7 +200,7 @@ class DiskCommon(object):
     def is_deleted(self):
         # The intention of this method is to check the file system to see if
         # the directory actually exists.
-        return not do_exists(self.datadir)
+        return not self._dir_exists
 
     def empty(self):
         # If it does not exist, then it is empty.  A value of True is
@@ -356,6 +357,8 @@ class DiskDir(DiskCommon):
             # object count and bytes used. Return immediately before metadata
             # validation and creation happens.
             info = do_stat(self.datadir)
+            if info and stat.S_ISDIR(info.st_mode):
+                self._dir_exists = True
             if not info:
                 # Container no longer exists.
                 return
@@ -526,7 +529,7 @@ class DiskDir(DiskCommon):
         return objects
 
     def get_info_is_deleted(self):
-        if not do_exists(self.datadir):
+        if not self._dir_exists:
             return {}, True
         info = self.get_info()
         return info, False
@@ -622,6 +625,7 @@ class DiskDir(DiskCommon):
         # where created by the code, but not by the
         # caller as objects
         rmobjdir(self.datadir)
+        self._dir_exists = False
 
     def set_x_container_sync_points(self, sync_point1, sync_point2):
         self.metadata['x_container_sync_point1'] = sync_point1
@@ -679,6 +683,8 @@ class DiskAccount(DiskCommon):
             # used. Return immediately before metadata validation and
             # creation happens.
             info = do_stat(self.datadir)
+            if info and stat.S_ISDIR(info.st_mode):
+                self._dir_exists = True
             semi_fake_md = {
                 'X-Object-Count': (0, 0),
                 'X-Container-Count': (0, 0),