fix a locking bug in MountFS.getsize

fs/mountfs.py

 #!/usr/bin/env python
 
-from base import *
-from objecttree import ObjectTree
-from memoryfs import MemoryFS
+from fs.base import *
+from fs.objecttree import ObjectTree
 
 
 class DirMount(object):
@@ -53,9 +52,8 @@ class MountFS(FS):
 
         return self, head_path, tail_path
 
+    @synchronize
     def desc(self, path):
-        self._lock.acquire()
-        try:
         fs, mount_path, delegate_path = self._delegate(path)
         if fs is self:
             if fs.isdir(path):
@@ -63,12 +61,9 @@ class MountFS(FS):
             else:
                 return "Mounted file"
         return "Mounted dir, maps to path %s on %s" % (delegate_path, str(fs))
-        finally:
-            self._lock.release()
 
+    @synchronize
     def isdir(self, path):
-        self._lock.acquire()
-        try:
         fs, mount_path, delegate_path = self._delegate(path)
         if fs is None:
             raise ResourceNotFoundError(path)
@@ -78,13 +73,9 @@ class MountFS(FS):
             return isinstance(object, dict)
         else:
             return fs.isdir(delegate_path)
-        finally:
-            self._lock.release()
 
+    @synchronize
     def isfile(self, path):
-
-        self._lock.acquire()
-        try:
         fs, mount_path, delegate_path = self._delegate(path)
         if fs is None:
             return ResourceNotFoundError(path)
@@ -94,13 +85,9 @@ class MountFS(FS):
             return type(object) is MountFS.FileMount
         else:
             return fs.isfile(delegate_path)
-        finally:
-            self._lock.release()
 
+    @synchronize
     def listdir(self, path="/", wildcard=None, full=False, absolute=False, dirs_only=False, files_only=False):
-
-        self._lock.acquire()
-        try:
         path = normpath(path)
         fs, mount_path, delegate_path = self._delegate(path)
 
@@ -134,24 +121,17 @@ class MountFS(FS):
                 paths = [pathjoin(path, p) for p in paths]
 
             return paths
-        finally:
-            self._lock.release()
 
+    @synchronize
     def makedir(self, path, recursive=False, allow_recreate=False):
         path = normpath(path)
-        self._lock.acquire()
-        try:
         fs, mount_path, delegate_path = self._delegate(path)
         if fs is self:
             raise UnsupportedError("make directory", msg="Can only makedir for mounted paths" )
         return fs.makedir(delegate_path, recursive=recursive, allow_recreate=allow_recreate)
-        finally:
-            self._lock.release()
 
+    @synchronize
     def open(self, path, mode="r", **kwargs):
-
-        self._lock.acquire()
-        try:
         path = normpath(path)
         object = self.mount_tree.get(path, None)
         if type(object) is MountFS.FileMount:
@@ -165,31 +145,19 @@ class MountFS(FS):
 
         return fs.open(delegate_path, mode, **kwargs)
 
-        finally:
-            self._lock.release()
 
+    @synchronize
     def exists(self, path):
-
-        self._lock.acquire()
-        try:
-
         path = normpath(path)
         fs, mount_path, delegate_path = self._delegate(path)
-
         if fs is None:
             return False
-
         if fs is self:
             return path in self.mount_tree
-
         return fs.exists(delegate_path)
 
-        finally:
-            self._lock.release()
-
+    @synchronize
     def remove(self, path):
-        self._lock.acquire()
-        try:
         path = normpath(path)
         fs, mount_path, delegate_path = self._delegate(path)
         if fs is None:
@@ -198,14 +166,8 @@ class MountFS(FS):
             raise UnsupportedError("remove file", msg="Can only remove paths within a mounted dir")
         return fs.remove(delegate_path)
 
-        finally:
-            self._lock.release()
-
+    @synchronize
     def removedir(self, path, recursive=False, force=False):
-
-        self._lock.acquire()
-        try:
-
         path = normpath(path)
         fs, mount_path, delegate_path = self._delegate(path)
 
@@ -217,16 +179,10 @@ class MountFS(FS):
 
         return fs.removedir(delegate_path, recursive, force)
 
-        finally:
-            self._lock.release()
-
+    @synchronize
     def rename(self, src, dst):
-
         if not issamedir(src, dst):
             raise ValueError("Destination path must the same directory (use the move method for moving to a different directory)")
-
-        self._lock.acquire()
-        try:
         fs1, mount_path1, delegate_path1 = self._delegate(src)
         fs2, mount_path2, delegate_path2 = self._delegate(dst)
 
@@ -246,11 +202,9 @@ class MountFS(FS):
             raise ResourceNotFoundError(src)
 
         # TODO!
-
         raise UnsupportedError("rename resource", path=src)
-        finally:
-            self._lock.release()
 
+    @synchronize
     def mountdir(self, path, fs):
         """Mounts a directory on a given path.
 
@@ -258,26 +212,17 @@ class MountFS(FS):
         fs -- A filesystem object to mount
 
         """
-        self._lock.acquire()
-        try:
         path = normpath(path)
         self.mount_tree[path] = MountFS.DirMount(path, fs)
-        finally:
-            self._lock.release()
     mount = mountdir
 
+    @synchronize
     def mountfile(self, path, open_callable=None, info_callable=None):
-        self._lock.acquire()
-        try:
         path = normpath(path)
         self.mount_tree[path] = MountFS.FileMount(path, callable, info_callable)
-        finally:
-            self._lock.release()
 
+    @synchronize
     def getinfo(self, path):
-
-        self._lock.acquire()
-        try:
         path = normpath(path)
 
         fs, mount_path, delegate_path = self._delegate(path)
@@ -290,12 +235,9 @@ class MountFS(FS):
                 return self.mount_tree[path].info_callable(path)
             return {}
         return fs.getinfo(delegate_path)
-        finally:
-            self._lock.release()
 
+    @synchronize
     def getsize(self, path):
-        self._lock.acquire()
-        try:
         path = normpath(path)
         fs, mount_path, delegate_path = self._delegate(path)
 
@@ -312,6 +254,4 @@ class MountFS(FS):
             return size
 
         return fs.getinfo(delegate_path).get("size", None)
-        except:
-            self._lock.release()