move saving all media items linked to a source when the source is sav…

…ed to recalculate media skip status to background task, resolves #94

tubesync/sync/signals.py

@@ -67,10 +67,13 @@ def source_post_save(sender, instance, created, **kwargs):
                 verbose_name=verbose_name.format(instance.name),
                 remove_existing_tasks=True
             )
-    # Trigger the post_save signal for each media item linked to this source as various
-    # flags may need to be recalculated
-    for media in Media.objects.filter(source=instance):
-        media.save()
+    verbose_name = _('Checking all media for source "{}"')
+    save_all_media_for_source(
+        str(instance.pk),
+        priority=0,
+        verbose_name=verbose_name.format(instance.name),
+        remove_existing_tasks=True
+    )
 
 
 @receiver(pre_delete, sender=Source)
@@ -82,7 +85,6 @@ def source_pre_delete(sender, instance, **kwargs):
         media.delete()
 
 
-
 @receiver(post_delete, sender=Source)
 def source_post_delete(sender, instance, **kwargs):
     # Triggered after a source is deleted
@@ -173,8 +175,6 @@ def media_post_save(sender, instance, created, **kwargs):
         )
 
 
-
-
 @receiver(pre_delete, sender=Media)
 def media_pre_delete(sender, instance, **kwargs):
     # Triggered before media is deleted, delete any scheduled tasks
@@ -195,7 +195,6 @@ def media_pre_delete(sender, instance, **kwargs):
             delete_file(file)
 
 
-
 @receiver(post_delete, sender=Media)
 def media_post_delete(sender, instance, **kwargs):
     # Schedule a task to update media servers

tubesync/sync/tasks.py

@@ -49,6 +49,7 @@ def map_task_to_instance(task):
         'sync.tasks.check_source_directory_exists': Source,
         'sync.tasks.download_media_thumbnail': Media,
         'sync.tasks.download_media': Media,
+        'sync.tasks.save_all_media_for_source': Source,
     }
     MODEL_URL_MAP = {
         Source: 'sync:source',
@@ -464,3 +465,24 @@ def rescan_media_server(mediaserver_id):
     # Request an rescan / update
     log.info(f'Updating media server: {mediaserver}')
     mediaserver.update()
+
+
+@background(schedule=0)
+def save_all_media_for_source(source_id):
+    '''
+        Iterates all media items linked to a source and saves them to
+        trigger the post_save signal for every media item. Used when a
+        source has its parameters changed and all media needs to be
+        checked to see if its download status has changed.
+    '''
+    try:
+        source = Source.objects.get(pk=source_id)
+    except Source.DoesNotExist:
+        # Task triggered but the source no longer exists, do nothing
+        log.error(f'Task save_all_media_for_source(pk={source_id}) called but no '
+                  f'source exists with ID: {source_id}')
+        return
+    # Trigger the post_save signal for each media item linked to this source as various
+    # flags may need to be recalculated
+    for media in Media.objects.filter(source=source):
+        media.save()