Redo total disk calculation adjustments to be less race condition-y.

... at least when finishing the job. Method should probably be used other places as well.

lib/galaxy/jobs/__init__.py

@@ -1329,7 +1329,7 @@ def path_rewriter( path ):
             bytes += dataset_assoc.dataset.dataset.get_total_size()
 
         if job.user:
-            job.user.total_disk_usage += bytes
+            job.user.adjust_total_disk_usage( bytes )
 
         # Empirically, we need to update job.user and
         # job.workflow_invocation_step.workflow_invocation in separate

lib/galaxy/model/__init__.py

@@ -204,6 +204,10 @@ def set_disk_usage( self, bytes ):
 
     total_disk_usage = property( get_disk_usage, set_disk_usage )
 
+    def adjust_total_disk_usage( self, amount ):
+        from sqlalchemy import func
+        self.disk_usage = func.coalesce(self.table.c.disk_usage, 0) + amount
+
     @property
     def nice_total_disk_usage( self ):
         """

test/unit/test_galaxy_mapping.py

@@ -230,6 +230,17 @@ def test_collections_in_library_folders(self):
         # self.assertEquals(len(loaded_dataset_collection.datasets), 2)
         # assert loaded_dataset_collection.collection_type == "pair"
 
+    def test_default_disk_usage( self ):
+        model = self.model
+
+        u = model.User( email="disk_default@test.com", password="password" )
+        self.persist( u )
+        u.adjust_total_disk_usage( 1 )
+        u_id = u.id
+        self.expunge()
+        user_reload = model.session.query( model.User ).get( u_id )
+        assert user_reload.disk_usage == 1
+
     def test_basic( self ):
         model = self.model