Have repo deletion not lock all the things

data/database.py

@@ -46,6 +46,32 @@ def real_for_update(query):
 def null_for_update(query):
   return query
 
+def _clear_log_entries(instance, model_class, log_entry_field, *extra_fields):
+  """ Temporary method for clearing out LogEntry records before the general deletion of a
+      dependent record (e.g. Repository or User). Used because deleting all of the log entries
+      under a transaction destroys the database for all other work.
+  """
+  # TODO: Remove this hack once LogEntry no longer has foreign key constraints to everything.
+  # Delete all records in LogEntry that reference the instance.
+  where_clause = (log_entry_field == instance)
+  for field in extra_fields:
+    where_clause = where_clause | (field == instance)
+
+  # Delete the log entries in chunks of 1000.
+  deleted_count = 1
+  while deleted_count >= 1:
+    todelete = (LogEntry
+                .select(LogEntry.id)
+                .where(where_clause)
+                .limit(1000)
+                .alias('todelete'))
+
+    subquery = (LogEntry
+                .select(todelete.c.id)
+                .from_(todelete))
+
+    deleted_count = LogEntry.delete().where(LogEntry.id << subquery).execute()
+
 def delete_instance_filtered(instance, model_class, delete_nullable, skip_transitive_deletes):
   """ Deletes the DB instance recursively, skipping any models in the skip_transitive_deletes set.
 
@@ -88,6 +114,7 @@ def delete_instance_filtered(instance, model_class, delete_nullable, skip_transi
   with db_transaction():
     for query, fk in filtered_ops:
       model = fk.model_class
+
       if fk.null and not delete_nullable:
         model.update(**{fk.name: None}).where(query).execute()
       else:
@@ -320,6 +347,7 @@ class User(BaseModel):
       # These models don't need to use transitive deletes, because the referenced objects
       # are cleaned up directly
       skip_transitive_deletes = {Image}
+      _clear_log_entries(self, User, LogEntry.performer, LogEntry.account)
       delete_instance_filtered(self, User, delete_nullable, skip_transitive_deletes)
 
 
@@ -416,7 +444,7 @@ class Repository(BaseModel):
     # are cleaned up directly
     skip_transitive_deletes = {RepositoryTag, RepositoryBuild, RepositoryBuildTrigger, BlobUpload,
                                Image, TagManifest, DerivedStorageForImage}
-
+    _clear_log_entries(self, User, LogEntry.repository)
     delete_instance_filtered(self, Repository, delete_nullable, skip_transitive_deletes)