Merge remote branch 'remotes/jwandborg/f571_closing_storage_objects'

mediagoblin/process_media/__init__.py

@@ -16,7 +16,6 @@
 
 import Image
 
-from contextlib import contextmanager
 from celery.task import Task
 from celery import registry
 
@@ -36,14 +35,6 @@ def create_pub_filepath(entry, filename):
              filename])
 
 
-@contextmanager
-def closing(callback):
-    try:
-        yield callback
-    finally:
-        pass
-
-
 ################################
 # Media processing initial steps
 ################################
@@ -66,7 +57,7 @@ class ProcessMedia(Task):
         except BaseProcessingFail, exc:
             mark_entry_failed(entry[u'_id'], exc)
             return
-            
+
         entry['state'] = u'processed'
         entry.save()
 
@@ -144,7 +135,7 @@ def process_image(entry):
     thumb_filepath = create_pub_filepath(entry, 'thumbnail.jpg')
     thumb_file = mgg.public_store.get_file(thumb_filepath, 'w')
 
-    with closing(thumb_file):
+    with thumb_file:
         thumb.save(thumb_file, "JPEG", quality=90)
 
     # If the size of the original file exceeds the specified size of a `medium`
@@ -162,7 +153,7 @@ def process_image(entry):
         medium_filepath = create_pub_filepath(entry, 'medium.jpg')
         medium_file = mgg.public_store.get_file(medium_filepath, 'w')
 
-        with closing(medium_file):
+        with medium_file:
             medium.save(medium_file, "JPEG", quality=90)
             medium_processed = True
 
@@ -172,8 +163,8 @@ def process_image(entry):
 
     with queued_file:
         original_filepath = create_pub_filepath(entry, queued_filepath[-1])
-        
-        with closing(mgg.public_store.get_file(original_filepath, 'wb')) as original_file:
+
+        with mgg.public_store.get_file(original_filepath, 'wb') as original_file:
             original_file.write(queued_file.read())
 
     mgg.queue_store.delete_file(queued_filepath)

mediagoblin/storage.py

@@ -291,7 +291,7 @@ class CloudFilesStorage(StorageInterface):
             if mimetype:
                 obj.content_type = mimetype[0]
 
-        return StorageObjectWrapper(obj, *args, **kwargs)
+        return CloudFilesStorageObjectWrapper(obj, *args, **kwargs)
 
     def delete_file(self, filepath):
         # TODO: Also delete unused directories if empty (safely, with
@@ -305,7 +305,7 @@ class CloudFilesStorage(StorageInterface):
                 self._resolve_filepath(filepath)])
 
 
-class StorageObjectWrapper():
+class CloudFilesStorageObjectWrapper():
     """
     Wrapper for python-cloudfiles's cloudfiles.storage_object.Object
     used to circumvent the mystic `medium.jpg` corruption issue, where
@@ -322,11 +322,38 @@ class StorageObjectWrapper():
         return self.storage_object.read(*args, **kwargs)
 
     def write(self, data, *args, **kwargs):
+        """
+        write data to the cloudfiles storage object
+
+        The original motivation for this wrapper is to ensure
+        that buffered writing to a cloudfiles storage object does not overwrite
+        any preexisting data.
+
+        Currently this method does not support any write modes except "append".
+        However if we should need it it would be easy implement.
+        """
         if self.storage_object.size and type(data) == str:
             data = self.read() + data
 
         self.storage_object.write(data, *args, **kwargs)
 
+    def close(self):
+        pass
+
+    def __enter__(self):
+        """
+        Context Manager API implementation
+        http://docs.python.org/library/stdtypes.html#context-manager-types
+        """
+        return self
+
+    def __exit__(self, *exc_info):
+        """
+        Context Manger API implementation
+        see self.__enter__()
+        """
+        self.close()
+
 
 # ------------
 # MountStorage