Implement asset metadata storage in Split - per-asset functionality

PLAT-40

Conflicts:
	common/lib/xmodule/xmodule/assetstore/__init__.py
	common/lib/xmodule/xmodule/modulestore/__init__.py
	common/lib/xmodule/xmodule/modulestore/mixed.py
	common/lib/xmodule/xmodule/modulestore/mongo/base.py

common/lib/xmodule/xmodule/assetstore/__init__.py

@@ -3,11 +3,13 @@ Classes representing asset & asset thumbnail metadata.
 """
 
 from datetime import datetime
+import pytz
 from contracts import contract, new_contract
 from opaque_keys.edx.keys import CourseKey, AssetKey
 
 new_contract('AssetKey', AssetKey)
 new_contract('datetime', datetime)
+new_contract('basestring', basestring)
 
 
 class IncorrectAssetIdType(Exception):
@@ -31,12 +33,13 @@ class AssetMetadata(object):
     # All AssetMetadata objects should have AssetLocators with this type.
     ASSET_TYPE = 'asset'
 
-    @contract(asset_id='AssetKey', basename='str | unicode | None', internal_name='str | None', locked='bool | None',
-              contenttype='str | unicode | None', md5='str | None', curr_version='str | None', prev_version='str | None')
+    @contract(asset_id='AssetKey', basename='basestring | None', internal_name='str | None', locked='bool | None', contenttype='basestring | None',
+              md5='str | None', curr_version='str | None', prev_version='str | None', edited_by='int | None', edited_on='datetime | None')
     def __init__(self, asset_id,
                  basename=None, internal_name=None,
                  locked=None, contenttype=None, md5=None,
-                 curr_version=None, prev_version=None):
+                 curr_version=None, prev_version=None,
+                 edited_by=None, edited_on=None, field_decorator=None):
         """
         Construct a AssetMetadata object.
 
@@ -48,10 +51,13 @@ class AssetMetadata(object):
             contenttype (str): MIME type of the asset.
             curr_version (str): Current version of the asset.
             prev_version (str): Previous version of the asset.
+            edited_by (str): Username of last user to upload this asset.
+            edited_on (datetime): Datetime of last upload of this asset.
+            field_decorator (function): used by strip_key to convert OpaqueKeys to the app's understanding
         """
         if asset_id.asset_type != self.ASSET_TYPE:
             raise IncorrectAssetIdType()
-        self.asset_id = asset_id
+        self.asset_id = asset_id if field_decorator is None else field_decorator(asset_id)
         self.basename = basename  # Path w/o filename.
         self.internal_name = internal_name
         self.locked = locked
@@ -59,8 +65,8 @@ class AssetMetadata(object):
         self.md5 = md5
         self.curr_version = curr_version
         self.prev_version = prev_version
-        self.edited_by = None
-        self.edited_on = None
+        self.edited_by = edited_by
+        self.edited_on = edited_on or datetime.now(pytz.utc)
 
     def __repr__(self):
         return """AssetMetadata{!r}""".format((
@@ -131,7 +137,7 @@ class AssetThumbnailMetadata(object):
     ASSET_TYPE = 'thumbnail'
 
     @contract(asset_id='AssetKey', internal_name='str | unicode | None')
-    def __init__(self, asset_id, internal_name=None):
+    def __init__(self, asset_id, internal_name=None, field_decorator=None):
         """
         Construct a AssetThumbnailMetadata object.
 
@@ -141,7 +147,7 @@ class AssetThumbnailMetadata(object):
         """
         if asset_id.asset_type != self.ASSET_TYPE:
             raise IncorrectAssetIdType()
-        self.asset_id = asset_id
+        self.asset_id = asset_id if field_decorator is None else field_decorator(asset_id)
         self.internal_name = internal_name
 
     def __repr__(self):

common/lib/xmodule/xmodule/modulestore/__init__.py

@@ -913,7 +913,7 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         """
         raise NotImplementedError()
 
-    @contract(course_key='CourseKey', asset_metadata='AssetMetadata', user_id='str | unicode')
+    @contract(course_key='CourseKey', asset_metadata='AssetMetadata')
     def save_asset_metadata(self, course_key, asset_metadata, user_id):
         """
         Saves the asset metadata for a particular course's asset.
@@ -928,7 +928,7 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         return self._save_asset_info(course_key, asset_metadata, user_id, thumbnail=False)
 
     @contract(course_key='CourseKey', asset_thumbnail_metadata='AssetThumbnailMetadata')
-    def save_asset_thumbnail_metadata(self, course_key, asset_thumbnail_metadata):
+    def save_asset_thumbnail_metadata(self, course_key, asset_thumbnail_metadata, user_id):
         """
         Saves the asset thumbnail metadata for a particular course asset's thumbnail.
 
@@ -939,10 +939,10 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         Returns:
             True if thumbnail metadata save was successful, else False
         """
-        return self._save_asset_info(course_key, asset_thumbnail_metadata, '', thumbnail=True)
+        return self._save_asset_info(course_key, asset_thumbnail_metadata, user_id, thumbnail=True)
 
     @contract(asset_key='AssetKey')
-    def _find_asset_info(self, asset_key, thumbnail=False):
+    def _find_asset_info(self, asset_key, thumbnail=False, **kwargs):
         """
         Find the info for a particular course asset/thumbnail.
 
@@ -959,16 +959,16 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
 
         if thumbnail:
             info = 'thumbnails'
-            mdata = AssetThumbnailMetadata(asset_key, asset_key.path)
+            mdata = AssetThumbnailMetadata(asset_key, asset_key.path, **kwargs)
         else:
             info = 'assets'
-            mdata = AssetMetadata(asset_key, asset_key.path)
+            mdata = AssetMetadata(asset_key, asset_key.path, **kwargs)
         all_assets = course_assets[info]
         mdata.from_mongo(all_assets[asset_idx])
         return mdata
 
     @contract(asset_key='AssetKey')
-    def find_asset_metadata(self, asset_key):
+    def find_asset_metadata(self, asset_key, **kwargs):
         """
         Find the metadata for a particular course asset.
 
@@ -978,10 +978,10 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         Returns:
             asset metadata (AssetMetadata) -or- None if not found
         """
-        return self._find_asset_info(asset_key, thumbnail=False)
+        return self._find_asset_info(asset_key, thumbnail=False, **kwargs)
 
     @contract(asset_key='AssetKey')
-    def find_asset_thumbnail_metadata(self, asset_key):
+    def find_asset_thumbnail_metadata(self, asset_key, **kwargs):
         """
         Find the metadata for a particular course asset.
 
@@ -991,10 +991,10 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         Returns:
             asset metadata (AssetMetadata) -or- None if not found
         """
-        return self._find_asset_info(asset_key, thumbnail=True)
+        return self._find_asset_info(asset_key, thumbnail=True, **kwargs)
 
     @contract(course_key='CourseKey', start='int | None', maxresults='int | None', sort='list | None', get_thumbnails='bool')
-    def _get_all_asset_metadata(self, course_key, start=0, maxresults=-1, sort=None, get_thumbnails=False):
+    def _get_all_asset_metadata(self, course_key, start=0, maxresults=-1, sort=None, get_thumbnails=False, **kwargs):
         """
         Returns a list of static asset (or thumbnail) metadata for a course.
 
@@ -1018,9 +1018,9 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
             return None
 
         if get_thumbnails:
-            all_assets = course_assets['thumbnails']
+            all_assets = course_assets.get('thumbnails', [])
         else:
-            all_assets = course_assets['assets']
+            all_assets = course_assets.get('assets', [])
 
         # DO_NEXT: Add start/maxresults/sort functionality as part of https://openedx.atlassian.net/browse/PLAT-74
         if start and maxresults and sort:
@@ -1029,17 +1029,24 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         ret_assets = []
         for asset in all_assets:
             if get_thumbnails:
-                thumb = AssetThumbnailMetadata(course_key.make_asset_key('thumbnail', asset['filename']),
-                                               internal_name=asset['filename'])
+                thumb = AssetThumbnailMetadata(
+                    course_key.make_asset_key('thumbnail', asset['filename']),
+                    internal_name=asset['filename'], **kwargs
+                )
                 ret_assets.append(thumb)
             else:
-                one_asset = AssetMetadata(course_key.make_asset_key('asset', asset['filename']))
-                one_asset.from_mongo(asset)
-                ret_assets.append(one_asset)
+                asset = AssetMetadata(
+                    course_key.make_asset_key('asset', asset['filename']),
+                    basename=asset['filename'],
+                    edited_on=asset['edit_info']['edited_on'],
+                    contenttype=asset['contenttype'],
+                    md5=str(asset['md5']), **kwargs
+                )
+                ret_assets.append(asset)
         return ret_assets
 
     @contract(course_key='CourseKey', start='int | None', maxresults='int | None', sort='list | None')
-    def get_all_asset_metadata(self, course_key, start=0, maxresults=-1, sort=None):
+    def get_all_asset_metadata(self, course_key, start=0, maxresults=-1, sort=None, **kwargs):
         """
         Returns a list of static assets for a course.
         By default all assets are returned, but start and maxresults can be provided to limit the query.
@@ -1056,10 +1063,10 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         Returns:
             List of AssetMetadata objects.
         """
-        return self._get_all_asset_metadata(course_key, start, maxresults, sort, get_thumbnails=False)
+        return self._get_all_asset_metadata(course_key, start, maxresults, sort, get_thumbnails=False, **kwargs)
 
     @contract(course_key='CourseKey')
-    def get_all_asset_thumbnail_metadata(self, course_key):
+    def get_all_asset_thumbnail_metadata(self, course_key, **kwargs):
         """
         Returns a list of thumbnails for all course assets.
 
@@ -1069,7 +1076,7 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         Returns:
             List of AssetThumbnailMetadata objects.
         """
-        return self._get_all_asset_metadata(course_key, get_thumbnails=True)
+        return self._get_all_asset_metadata(course_key, get_thumbnails=True, **kwargs)
 
     def set_asset_metadata_attrs(self, asset_key, attrs, user_id):
         """
@@ -1077,7 +1084,7 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         """
         raise NotImplementedError()
 
-    def _delete_asset_data(self, asset_key, thumbnail=False):
+    def _delete_asset_data(self, asset_key, user_id, thumbnail=False):
         """
         Base method to over-ride in modulestore.
         """
@@ -1100,7 +1107,7 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         return self.set_asset_metadata_attrs(asset_key, {attr: value}, user_id)
 
     @contract(asset_key='AssetKey')
-    def delete_asset_metadata(self, asset_key):
+    def delete_asset_metadata(self, asset_key, user_id):
         """
         Deletes a single asset's metadata.
 
@@ -1110,10 +1117,10 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         Returns:
             Number of asset metadata entries deleted (0 or 1)
         """
-        return self._delete_asset_data(asset_key, thumbnail=False)
+        return self._delete_asset_data(asset_key, user_id, thumbnail=False)
 
     @contract(asset_key='AssetKey')
-    def delete_asset_thumbnail_metadata(self, asset_key):
+    def delete_asset_thumbnail_metadata(self, asset_key, user_id):
         """
         Deletes a single asset's metadata.
 
@@ -1123,10 +1130,10 @@ class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
         Returns:
             Number of asset metadata entries deleted (0 or 1)
         """
-        return self._delete_asset_data(asset_key, thumbnail=True)
+        return self._delete_asset_data(asset_key, user_id, thumbnail=True)
 
     @contract(source_course_key='CourseKey', dest_course_key='CourseKey')
-    def copy_all_asset_metadata(self, source_course_key, dest_course_key):
+    def copy_all_asset_metadata(self, source_course_key, dest_course_key, user_id):
         """
         Copy all the course assets from source_course_key to dest_course_key.
 

common/lib/xmodule/xmodule/modulestore/mixed.py

@@ -315,24 +315,6 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
         store = self._get_modulestore_for_courseid(course_key)
         return store.delete_course(course_key, user_id)
 
-    def _save_asset_info(self, course_key, asset_metadata, user_id, thumbnail=False):
-        """
-        Base method to over-ride in modulestore.
-        """
-        raise NotImplementedError()
-
-    def _delete_asset_data(self, asset_key, thumbnail=False):
-        """
-        Base method to over-ride in modulestore.
-        """
-        raise NotImplementedError()
-
-    def _find_course_assets(self, course_key):
-        """
-        Base method to override.
-        """
-        raise NotImplementedError()
-
     @contract(course_key='CourseKey', asset_metadata='AssetMetadata')
     def save_asset_metadata(self, course_key, asset_metadata, user_id):
         """
@@ -341,30 +323,25 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
         Args:
         course_key (CourseKey): course identifier
         asset_metadata (AssetMetadata): data about the course asset data
-
-        Returns:
-            bool: True if metadata save was successful, else False
         """
         store = self._get_modulestore_for_courseid(course_key)
         return store.save_asset_metadata(course_key, asset_metadata, user_id)
 
     @contract(course_key='CourseKey', asset_thumbnail_metadata='AssetThumbnailMetadata')
-    def save_asset_thumbnail_metadata(self, course_key, asset_thumbnail_metadata):
+    def save_asset_thumbnail_metadata(self, course_key, asset_thumbnail_metadata, user_id):
         """
         Saves the asset thumbnail metadata for a particular course asset's thumbnail.
 
         Arguments:
             course_key (CourseKey): course identifier
             asset_thumbnail_metadata (AssetThumbnailMetadata): data about the course asset thumbnail
-
-        Returns:
-            True if thumbnail metadata save was successful, else False
         """
         store = self._get_modulestore_for_courseid(course_key)
-        return store.save_asset_metadata(course_key, asset_thumbnail_metadata)
+        return store.save_asset_thumbnail_metadata(course_key, asset_thumbnail_metadata, user_id)
 
+    @strip_key
     @contract(asset_key='AssetKey')
-    def find_asset_metadata(self, asset_key):
+    def find_asset_metadata(self, asset_key, **kwargs):
         """
         Find the metadata for a particular course asset.
 
@@ -375,10 +352,11 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
             asset metadata (AssetMetadata) -or- None if not found
         """
         store = self._get_modulestore_for_courseid(asset_key.course_key)
-        return store.find_asset_metadata(asset_key)
+        return store.find_asset_metadata(asset_key, **kwargs)
 
+    @strip_key
     @contract(asset_key='AssetKey')
-    def find_asset_thumbnail_metadata(self, asset_key):
+    def find_asset_thumbnail_metadata(self, asset_key, **kwargs):
         """
         Find the metadata for a particular course asset.
 
@@ -389,10 +367,11 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
             asset metadata (AssetMetadata) -or- None if not found
         """
         store = self._get_modulestore_for_courseid(asset_key.course_key)
-        return store.find_asset_thumbnail_metadata(asset_key)
+        return store.find_asset_thumbnail_metadata(asset_key, **kwargs)
 
+    @strip_key
     @contract(course_key='CourseKey', start=int, maxresults=int, sort='list | None')
-    def get_all_asset_metadata(self, course_key, start=0, maxresults=-1, sort=None):
+    def get_all_asset_metadata(self, course_key, start=0, maxresults=-1, sort=None, **kwargs):
         """
         Returns a list of static assets for a course.
         By default all assets are returned, but start and maxresults can be provided to limit the query.
@@ -415,10 +394,11 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
                 md5: An md5 hash of the asset content
         """
         store = self._get_modulestore_for_courseid(course_key)
-        return store.get_all_asset_metadata(course_key, start, maxresults, sort)
+        return store.get_all_asset_metadata(course_key, start, maxresults, sort, **kwargs)
 
+    @strip_key
     @contract(course_key='CourseKey')
-    def get_all_asset_thumbnail_metadata(self, course_key):
+    def get_all_asset_thumbnail_metadata(self, course_key, **kwargs):
         """
         Returns a list of thumbnails for all course assets.
 
@@ -429,10 +409,10 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
             List of AssetThumbnailMetadata objects.
         """
         store = self._get_modulestore_for_courseid(course_key)
-        return store.get_all_asset_thumbnail_metadata(course_key)
+        return store.get_all_asset_thumbnail_metadata(course_key, **kwargs)
 
     @contract(asset_key='AssetKey')
-    def delete_asset_metadata(self, asset_key):
+    def delete_asset_metadata(self, asset_key, user_id):
         """
         Deletes a single asset's metadata.
 
@@ -443,10 +423,10 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
             Number of asset metadata entries deleted (0 or 1)
         """
         store = self._get_modulestore_for_courseid(asset_key.course_key)
-        return store.delete_asset_metadata(asset_key)
+        return store.delete_asset_metadata(asset_key, user_id)
 
     @contract(asset_key='AssetKey')
-    def delete_asset_thumbnail_metadata(self, asset_key):
+    def delete_asset_thumbnail_metadata(self, asset_key, user_id):
         """
         Deletes a single asset's metadata.
 
@@ -457,10 +437,10 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
             Number of asset metadata entries deleted (0 or 1)
         """
         store = self._get_modulestore_for_courseid(asset_key.course_key)
-        return store.delete_asset_metadata(asset_key)
+        return store.delete_asset_thumbnail_metadata(asset_key, user_id)
 
     @contract(course_key='CourseKey')
-    def delete_all_asset_metadata(self, course_key):
+    def delete_all_asset_metadata(self, course_key, user_id):
         """
         Delete all of the assets which use this course_key as an identifier.
 
@@ -468,10 +448,10 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
             course_key (CourseKey): course_identifier
         """
         store = self._get_modulestore_for_courseid(course_key)
-        return store.delete_all_asset_metadata(course_key)
+        return store.delete_all_asset_metadata(course_key, user_id)
 
     @contract(source_course_key='CourseKey', dest_course_key='CourseKey')
-    def copy_all_asset_metadata(self, source_course_key, dest_course_key):
+    def copy_all_asset_metadata(self, source_course_key, dest_course_key, user_id):
         """
         Copy all the course assets from source_course_key to dest_course_key.
 
@@ -483,7 +463,7 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
         #  Check the modulestores of both the source and dest course_keys. If in different modulestores,
         #  export all asset data from one modulestore and import it into the dest one.
         store = self._get_modulestore_for_courseid(source_course_key)
-        return store.copy_all_asset_metadata(source_course_key, dest_course_key)
+        return store.copy_all_asset_metadata(source_course_key, dest_course_key, user_id)
 
     @contract(asset_key='AssetKey', attr=str)
     def set_asset_metadata_attr(self, asset_key, attr, value, user_id):
@@ -500,7 +480,7 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
             AttributeError is attr is one of the build in attrs.
         """
         store = self._get_modulestore_for_courseid(asset_key.course_key)
-        return store.set_asset_metadata_attrs(asset_key, attr, value, user_id)
+        return store.set_asset_metadata_attrs(asset_key, {attr: value}, user_id)
 
     @contract(asset_key='AssetKey', attr_dict=dict)
     def set_asset_metadata_attrs(self, asset_key, attr_dict, user_id):

common/lib/xmodule/xmodule/modulestore/mongo/base.py

@@ -1474,7 +1474,7 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
 
         return course_assets
 
-    @contract(course_key='CourseKey', asset_metadata='AssetMetadata | AssetThumbnailMetadata', user_id='str | unicode')
+    @contract(course_key='CourseKey', asset_metadata='AssetMetadata | AssetThumbnailMetadata')
     def _save_asset_info(self, course_key, asset_metadata, user_id, thumbnail=False):
         """
         Saves the info for a particular course's asset/thumbnail.
@@ -1537,7 +1537,6 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
         md = AssetMetadata(asset_key, asset_key.path)
         md.from_mongo(all_assets[asset_idx])
         md.update(attr_dict)
-        md.update({'edited_by': user_id, 'edited_on': datetime.now(UTC)})
 
         # Generate a Mongo doc from the metadata and update the course asset info.
         all_assets[asset_idx] = md.to_mongo()
@@ -1545,7 +1544,7 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
         self.asset_collection.update({'_id': course_assets['_id']}, {"$set": {'assets': all_assets}})
 
     @contract(asset_key='AssetKey')
-    def _delete_asset_data(self, asset_key, thumbnail=False):
+    def _delete_asset_data(self, asset_key, user_id, thumbnail=False):
         """
         Internal; deletes a single asset's metadata -or- thumbnail.
 
@@ -1572,8 +1571,9 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
         self.asset_collection.update({'_id': course_assets['_id']}, {'$set': {info: all_asset_info}})
         return 1
 
+    # pylint: disable=unused-argument
     @contract(course_key='CourseKey')
-    def delete_all_asset_metadata(self, course_key):
+    def delete_all_asset_metadata(self, course_key, user_id):
         """
         Delete all of the assets which use this course_key as an identifier.
 

common/lib/xmodule/xmodule/modulestore/split_mongo/split.py

@@ -80,6 +80,7 @@ from xmodule.modulestore.split_mongo import BlockKey, CourseEnvelope
 from xmodule.error_module import ErrorDescriptor
 from collections import defaultdict
 from types import NoneType
+from xmodule.assetstore import AssetMetadata
 
 
 log = logging.getLogger(__name__)
@@ -1174,7 +1175,7 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
         Find the version_history_depth next versions of this definition. Return as a VersionTree
         '''
         # TODO implement
-        raise NotImplementedError()
+        pass
 
     def create_definition_from_data(self, course_key, new_def_data, category, user_id):
         """
@@ -2120,6 +2121,180 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
         """
         return ModuleStoreEnum.Type.split
 
+    def _find_course_assets(self, course_key):
+        """
+        Split specific lookup
+        """
+        return self._lookup_course(course_key).structure
+
+    def _find_course_asset(self, course_key, filename, get_thumbnail=False):
+        structure = self._lookup_course(course_key).structure
+        return structure, self._lookup_course_asset(structure, filename, get_thumbnail)
+
+    def _lookup_course_asset(self, structure, filename, get_thumbnail=False):
+        """
+        Find the course asset in the structure or return None if it does not exist
+        """
+        # See if this asset already exists by checking the external_filename.
+        # Studio doesn't currently support using multiple course assets with the same filename.
+        # So use the filename as the unique identifier.
+        accessor = 'thumbnails' if get_thumbnail else 'assets'
+        for idx, asset in enumerate(structure.get(accessor, [])):
+            if asset['filename'] == filename:
+                return idx
+        return None
+
+    def _update_course_assets(self, user_id, asset_key, update_function, get_thumbnail=False):
+        """
+        A wrapper for functions wanting to manipulate assets. Gets and versions the structure,
+        passes the mutable array for either 'assets' or 'thumbnails' as well as the idx to the function for it to
+        update, then persists the changed data back into the course.
+
+        The update function can raise an exception if it doesn't want to actually do the commit. The
+        surrounding method probably should catch that exception.
+        """
+        with self.bulk_operations(asset_key.course_key):
+            original_structure = self._lookup_course(asset_key.course_key).structure
+            index_entry = self._get_index_if_valid(asset_key.course_key)
+            new_structure = self.version_structure(asset_key.course_key, original_structure, user_id)
+
+            accessor = 'thumbnails' if get_thumbnail else 'assets'
+            asset_idx = self._lookup_course_asset(new_structure, asset_key.path, get_thumbnail)
+
+            new_structure[accessor] = update_function(new_structure.get(accessor, []), asset_idx)
+
+            # update index if appropriate and structures
+            self.update_structure(asset_key.course_key, new_structure)
+
+            if index_entry is not None:
+                # update the index entry if appropriate
+                self._update_head(asset_key.course_key, index_entry, asset_key.branch, new_structure['_id'])
+
+    def _save_asset_info(self, course_key, asset_metadata, user_id, thumbnail=False):
+        """
+        The guts of saving a new or updated asset
+        """
+        metadata_to_insert = asset_metadata.to_mongo()
+
+        def _internal_method(all_assets, asset_idx):
+            """
+            Either replace the existing entry or add a new one
+            """
+            if asset_idx is None:
+                all_assets.append(metadata_to_insert)
+            else:
+                all_assets[asset_idx] = metadata_to_insert
+            return all_assets
+
+        return self._update_course_assets(user_id, asset_metadata.asset_id, _internal_method, thumbnail)
+
+    @contract(asset_key='AssetKey', attr_dict=dict)
+    def set_asset_metadata_attrs(self, asset_key, attr_dict, user_id):
+        """
+        Add/set the given dict of attrs on the asset at the given location. Value can be any type which pymongo accepts.
+
+        Arguments:
+            asset_key (AssetKey): asset identifier
+            attr_dict (dict): attribute: value pairs to set
+
+        Raises:
+            ItemNotFoundError if no such item exists
+            AttributeError is attr is one of the build in attrs.
+        """
+        def _internal_method(all_assets, asset_idx):
+            """
+            Update the found item
+            """
+            if asset_idx is None:
+                raise ItemNotFoundError(asset_key)
+
+            # Form an AssetMetadata.
+            mdata = AssetMetadata(asset_key, asset_key.path)
+            mdata.from_mongo(all_assets[asset_idx])
+            mdata.update(attr_dict)
+
+            # Generate a Mongo doc from the metadata and update the course asset info.
+            all_assets[asset_idx] = mdata.to_mongo()
+            return all_assets
+
+        self._update_course_assets(user_id, asset_key, _internal_method, False)
+
+    @contract(asset_key='AssetKey')
+    def _delete_asset_data(self, asset_key, user_id, thumbnail=False):
+        """
+        Internal; deletes a single asset's metadata -or- thumbnail.
+
+        Arguments:
+            asset_key (AssetKey): key containing original asset/thumbnail filename
+            thumbnail: True if thumbnail deletion, False if asset metadata deletion
+
+        Returns:
+            Number of asset metadata/thumbnail entries deleted (0 or 1)
+        """
+        def _internal_method(all_asset_info, asset_idx):
+            """
+            Remove the item if it was found
+            """
+            if asset_idx is None:
+                raise ItemNotFoundError(asset_key)
+
+            all_asset_info.pop(asset_idx)
+            return all_asset_info
+
+        try:
+            self._update_course_assets(user_id, asset_key, _internal_method, thumbnail)
+            return 1
+        except ItemNotFoundError:
+            return 0
+
+    @contract(course_key='CourseKey')
+    def delete_all_asset_metadata(self, course_key, user_id):
+        """
+        Delete all of the assets which use this course_key as an identifier.
+
+        Arguments:
+            course_key (CourseKey): course_identifier
+        """
+        with self.bulk_operations(course_key):
+            original_structure = self._lookup_course(course_key).structure
+            index_entry = self._get_index_if_valid(course_key)
+            new_structure = self.version_structure(course_key, original_structure, user_id)
+
+            new_structure['assets'] = []
+            new_structure['thumbnails'] = []
+
+            # update index if appropriate and structures
+            self.update_structure(course_key, new_structure)
+
+            if index_entry is not None:
+                # update the index entry if appropriate
+                self._update_head(course_key, index_entry, course_key.branch, new_structure['_id'])
+
+    @contract(source_course_key='CourseKey', dest_course_key='CourseKey')
+    def copy_all_asset_metadata(self, source_course_key, dest_course_key, user_id):
+        """
+        Copy all the course assets from source_course_key to dest_course_key.
+
+        Arguments:
+            source_course_key (CourseKey): identifier of course to copy from
+            dest_course_key (CourseKey): identifier of course to copy to
+        """
+        source_structure = self._lookup_course(source_course_key).structure
+        with self.bulk_operations(dest_course_key):
+            original_structure = self._lookup_course(dest_course_key).structure
+            index_entry = self._get_index_if_valid(dest_course_key)
+            new_structure = self.version_structure(dest_course_key, original_structure, user_id)
+
+            new_structure['assets'] = source_structure.get('assets', [])
+            new_structure['thumbnails'] = source_structure.get('thumbnails', [])
+
+            # update index if appropriate and structures
+            self.update_structure(dest_course_key, new_structure)
+
+            if index_entry is not None:
+                # update the index entry if appropriate
+                self._update_head(dest_course_key, index_entry, dest_course_key.branch, new_structure['_id'])
+
     def internal_clean_children(self, course_locator):
         """
         Only intended for rather low level methods to use. Goes through the children attrs of

common/lib/xmodule/xmodule/modulestore/split_mongo/split_draft.py

@@ -2,7 +2,7 @@
 Module for the dual-branch fall-back Draft->Published Versioning ModuleStore
 """
 
-from split import SplitMongoModuleStore, EXCLUDE_ALL
+from xmodule.modulestore.split_mongo.split import SplitMongoModuleStore, EXCLUDE_ALL
 from xmodule.exceptions import InvalidVersionError
 from xmodule.modulestore import ModuleStoreEnum
 from xmodule.modulestore.exceptions import InsufficientSpecificationError
@@ -13,7 +13,7 @@ from opaque_keys.edx.locator import CourseLocator
 from xmodule.modulestore.split_mongo import BlockKey
 
 
-class DraftVersioningModuleStore(ModuleStoreDraftAndPublished, SplitMongoModuleStore):
+class DraftVersioningModuleStore(SplitMongoModuleStore, ModuleStoreDraftAndPublished):
     """
     A subclass of Split that supports a dual-branch fall-back versioning framework
         with a Draft branch that falls back to a Published branch.
@@ -43,9 +43,9 @@ class DraftVersioningModuleStore(ModuleStoreDraftAndPublished, SplitMongoModuleS
                 # create any other necessary things as a side effect: ensure they populate the draft branch
                 # and rely on auto publish to populate the published branch: split's create course doesn't
                 # call super b/c it needs the auto publish above to have happened before any of the create_items
-                # in this. The explicit use of SplitMongoModuleStore is intentional
+                # in this; so, this manually calls the grandparent and above methods.
                 with self.branch_setting(ModuleStoreEnum.Branch.draft_preferred, item.id):
-                    # pylint: disable=bad-super-call
+                    # NOTE: DO NOT CHANGE THE SUPER. See comment above
                     super(SplitMongoModuleStore, self).create_course(
                         org, course, run, user_id, runtime=item.runtime, **kwargs
                     )
@@ -229,7 +229,7 @@ class DraftVersioningModuleStore(ModuleStoreDraftAndPublished, SplitMongoModuleS
         if revision == ModuleStoreEnum.RevisionOption.draft_preferred:
             revision = ModuleStoreEnum.RevisionOption.draft_only
         location = self._map_revision_to_branch(location, revision=revision)
-        return SplitMongoModuleStore.get_parent_location(self, location, **kwargs)
+        return super(DraftVersioningModuleStore, self).get_parent_location(location, **kwargs)
 
     def get_orphans(self, course_key, **kwargs):
         course_key = self._map_revision_to_branch(course_key)
@@ -275,8 +275,7 @@ class DraftVersioningModuleStore(ModuleStoreDraftAndPublished, SplitMongoModuleS
         Publishes the subtree under location from the draft branch to the published branch
         Returns the newly published item.
         """
-        SplitMongoModuleStore.copy(
-            self,
+        super(DraftVersioningModuleStore, self).copy(
             user_id,
             # Directly using the replace function rather than the for_branch function
             # because for_branch obliterates the version_guid and will lead to missed version conflicts.
@@ -446,3 +445,62 @@ class DraftVersioningModuleStore(ModuleStoreDraftAndPublished, SplitMongoModuleS
         if published_block is not None:
             setattr(xblock, '_published_by', published_block['edit_info']['edited_by'])
             setattr(xblock, '_published_on', published_block['edit_info']['edited_on'])
+
+    def _find_asset_info(self, asset_key, thumbnail=False, **kwargs):
+        return super(DraftVersioningModuleStore, self)._find_asset_info(
+            self._map_revision_to_branch(asset_key), thumbnail, **kwargs
+        )
+
+    def _get_all_asset_metadata(self, course_key, start=0, maxresults=-1, sort=None, get_thumbnails=False, **kwargs):
+        return super(DraftVersioningModuleStore, self)._get_all_asset_metadata(
+            self._map_revision_to_branch(course_key), start, maxresults, sort, get_thumbnails, **kwargs
+        )
+
+    def _update_course_assets(self, user_id, asset_key, update_function, get_thumbnail=False):
+        """
+        Updates both the published and draft branches
+        """
+        # if one call gets an exception, don't do the other call but pass on the exception
+        super(DraftVersioningModuleStore, self)._update_course_assets(
+            user_id, self._map_revision_to_branch(asset_key, ModuleStoreEnum.RevisionOption.published_only),
+            update_function, get_thumbnail
+        )
+        super(DraftVersioningModuleStore, self)._update_course_assets(
+            user_id, self._map_revision_to_branch(asset_key, ModuleStoreEnum.RevisionOption.draft_only),
+            update_function, get_thumbnail
+        )
+
+    def _find_course_asset(self, course_key, filename, get_thumbnail=False):
+        return super(DraftVersioningModuleStore, self)._find_course_asset(
+            self._map_revision_to_branch(course_key), filename, get_thumbnail=get_thumbnail
+        )
+
+    def _find_course_assets(self, course_key):
+        """
+        Split specific lookup
+        """
+        return super(DraftVersioningModuleStore, self)._find_course_assets(
+            self._map_revision_to_branch(course_key)
+        )
+
+    def delete_all_asset_metadata(self, course_key, user_id):
+        """
+        Deletes from both branches
+        """
+        super(DraftVersioningModuleStore, self).delete_all_asset_metadata(
+            self._map_revision_to_branch(course_key, ModuleStoreEnum.RevisionOption.published_only), user_id
+        )
+        super(DraftVersioningModuleStore, self).delete_all_asset_metadata(
+            self._map_revision_to_branch(course_key, ModuleStoreEnum.RevisionOption.draft_only), user_id
+        )
+
+    def copy_all_asset_metadata(self, source_course_key, dest_course_key, user_id):
+        """
+        Copies to and from both branches
+        """
+        for revision in [ModuleStoreEnum.RevisionOption.published_only, ModuleStoreEnum.RevisionOption.draft_only]:
+            super(DraftVersioningModuleStore, self).copy_all_asset_metadata(
+                self._map_revision_to_branch(source_course_key, revision),
+                self._map_revision_to_branch(dest_course_key, revision),
+                user_id
+            )