ContentStreamForPruning

This model reflects if content streams are currently in use or not. Each content stream is first CREATED or FORKED, and then moves to the IN_USE or REBASE_ERROR states; or is removed directly in case of temporary content streams.

FORKING: Content streams are forked from a base content stream. It can happen that the base content stream is NO_LONGER_IN_USE, but the child content stream is still IN_USE_BY_WORKSPACE. In this case, the base content stream can go to removed=true (removed from the content graph), but needs to be retained in the event store: If we do a full replay, we need the events of the base content stream before the fork happened to rebuild the child content stream. This logic is done in {\Neos\ContentRepository\Core\Service\ContentStreamPruner\ContentStreamPruner::findUnusedAndRemovedContentStreamIds()}.

TEMPORARY content streams: Projections should take care to dispose their temporary content streams, by triggering a ContentStreamWasRemoved event after the content stream is no longer used.

The different status a content stream can be in

       │                       │
       │(for root              │during
       │ content               │rebase
       ▼ stream)               ▼
 ┌──────────┐            ┌──────────┐             Temporary
 │ CREATED  │            │  FORKED  │────┐          status
 └──────────┘            └──────────┘    for
       │                       │      temporary
       ├───────────────────────┤       content
       ▼                       │       streams

┌───────────────────┐ │ │ │IN_USE_BY_WORKSPACE│ │ │ └───────────────────┘ │ │ Persistent │ │ │ status ▼ │ │ ┌───────────────────┐ │ │ │ NO_LONGER_IN_USE │ │ │ └───────────────────┘ │ │ │ │ │ └──────────┬────────────┘ │ ▼ │ ┌────────────────────────────────────────┐ │ │ removed=true │ │ │ => removed from content graph │◀─┘ └────────────────────────────────────────┘ Cleanup │ ▼ ┌────────────────────────────────────────┐ │ completely deleted from event stream │ └────────────────────────────────────────┘