Proper handling of processor failures, working as hoped!

BaseProcessingFail based exceptions recorded and marked appropriately
in the database.  Other exceptions also caught and marked (or rather
not marked) appropriately in the database as well.

mediagoblin/submit/views.py

@@ -14,9 +14,10 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import uuid
+
 from os.path import splitext
 from cgi import FieldStorage
-from string import split
 
 from werkzeug.utils import secure_filename
 
@@ -27,7 +28,7 @@ from mediagoblin.util import (
 from mediagoblin.util import pass_to_ugettext as _
 from mediagoblin.decorators import require_active_login
 from mediagoblin.submit import forms as submit_forms, security
-from mediagoblin.process_media import process_media_initial
+from mediagoblin.process_media import process_media
 from mediagoblin.messages import add_message, SUCCESS
 
 
@@ -87,15 +88,24 @@ def submit_start(request):
             # Add queued filename to the entry
             entry['queued_media_file'] = queue_filepath
 
+            # We generate this ourselves so we know what the taks id is for
+            # retrieval later.
+            # (If we got it off the task's auto-generation, there'd be a risk of
+            # a race condition when we'd save after sending off the task)
+            task_id = unicode(uuid.uuid4())
+            entry['queued_task_id'] = task_id
+
             # Save now so we have this data before kicking off processing
-            entry.save(validate=False)
-
-            result = process_media_initial.delay(unicode(entry['_id']))
-
-            # Save the task id
-            entry['queued_task_id'] = unicode(result.task_id)
             entry.save(validate=True)
 
+            # Pass off to processing
+            #
+            # (... don't change entry after this point to avoid race
+            # conditions with changes to the document via processing code)
+            process_media.apply_async(
+                [unicode(entry['_id'])], {},
+                task_id=task_id)
+
             add_message(request, SUCCESS, _('Woohoo! Submitted!'))
 
             return redirect(request, "mediagoblin.user_pages.user_home",