def _delete_source_collection_from_db()

in client/securedrop_client/storage.py [0:0]

• 32 lines of code
• 9 McCabe index (conditional complexity)

def _delete_source_collection_from_db(session: Session, source: Source) -> None:
    """
    Delete message, reply, draft, and file records belonging to a given source.

    Create new DeletedConversation record to temporarily flag UUIDs of sources whose
    conversations have been locally deleted, to prevent them from being re-added to
    the database during a network race condition.

    Source UUID is used because storing it does not expose any additional identifying
    information about the source (compared to the source `id` field).
    """

    is_local_db_modified = False

    for table in (DraftReply, File, Message, Reply):
        try:
            query = session.query(table).filter_by(source_id=source.id)
            if len(query.all()) > 0:
                logger.debug(
                    f"Locally delete {table.__name__} records associated with source {source.uuid}"
                )
                query.delete()
                is_local_db_modified = True
        except NoResultFound:
            #  Sync logic has deleted the records
            logger.debug(
                f"Tried to locally delete {table.__name__} records associated with "
                f"source {source.uuid}, but none were found"
            )

    # Add source UUID to deletedconversation table, but only if we actually made
    # local database modifications
    if is_local_db_modified:
        flagged_conversation = DeletedConversation(uuid=source.uuid)
        try:
            if not session.query(DeletedConversation).filter_by(uuid=source.uuid).one_or_none():
                logger.debug(f"Add source {source.uuid} to deletedconversation table")
                session.add(flagged_conversation)
        except SQLAlchemyError as e:
            logger.error(f"Could not add source {source.uuid} to deletedconversation table")
            logger.debug(f"Could not add source {source.uuid} to deletedconversation table: {e}")
            session.rollback()

    try:
        session.commit()
    except SQLAlchemyError as e:
        logger.error(f"Could not locally delete conversation for source {source.uuid}")
        logger.debug(f"Could not locally delete conversation for source {source.uuid}: {e}")
        session.rollback()