Make repository deletes much faster by adding custom deletion code and have additional tests to verify the deletion code paths

data/database.py

@@ -245,6 +245,24 @@ class Repository(BaseModel):
       (('namespace_user', 'name'), True),
     )
 
+  def delete_instance(self, recursive=False, delete_nullable=False):
+    # Note: peewee generates extra nested deletion statements here that are slow and unnecessary.
+    # Therefore, we define our own deletion order here and use the dependency system to verify it.
+    ordered_dependencies = [RepositoryAuthorizedEmail, RepositoryTag, Image, LogEntry,
+                            RepositoryBuild, RepositoryBuildTrigger, RepositoryNotification,
+                            RepositoryPermission, AccessToken]                          
+
+    for query, fk in self.dependencies(search_nullable=True):
+      model = fk.model_class
+      if not model in ordered_dependencies:
+        raise Exception('Missing repository deletion dependency: %s', model)
+
+    for model in ordered_dependencies:
+      model.delete().where(model.repository == self).execute()
+
+    # Delete the repository itself.
+    super(Repository, self).delete_instance(recursive=False, delete_nullable=False)
+
 
 class Role(BaseModel):
   name = CharField(index=True, unique=True)
@@ -441,7 +459,6 @@ class LogEntry(BaseModel):
   performer = QuayUserField(allows_robots=True, index=True, null=True,
                             related_name='performer')  
   repository = ForeignKeyField(Repository, index=True, null=True)
-  access_token = ForeignKeyField(AccessToken, null=True)
   datetime = DateTimeField(default=datetime.now, index=True)
   ip = CharField(null=True)
   metadata_json = TextField(default='{}')

data/model/legacy.py

@@ -1774,7 +1774,7 @@ def purge_repository(namespace_name, repository_name):
 
   # Delete the rest of the repository metadata
   fetched = _get_repository(namespace_name, repository_name)
-  fetched.delete_instance(recursive=True)
+  fetched.delete_instance(recursive=True, delete_nullable=True)
 
 
 def get_private_repo_count(username):
@@ -2004,7 +2004,7 @@ def log_action(kind_name, user_or_organization_name, performer=None,
   kind = LogEntryKind.get(LogEntryKind.name == kind_name)
   account = User.get(User.username == user_or_organization_name)
   LogEntry.create(kind=kind, account=account, performer=performer,
-                  repository=repository, access_token=access_token, ip=ip,
+                  repository=repository, ip=ip,
                   metadata_json=json.dumps(metadata), datetime=timestamp)