Export via streaming serializer, introduce "Writer" abstraction
Summary
As part of our effort to introduce .ndjson as a way to process imports(&2734), we should ship streaming serializer, and refactor legacy json to use streaming serializer.
It will be an improvement on its own, since it would bring constant memory usage on exporting side for legacy format (big file), because we don't need to store the whole JSON in memory anymore as we write and forget...
We should:
- Introduce streaming serializer as a drop-in replacement for
FastHashSerializer - a
Writercan persist relations in different ways - it would still produce a "fat JSON" so no ndjson here yet
- there would be no structural changes here yet, it's mostly a refactor
Links / references
POC MR: !23920 (closed)
Epic: &2734