dendrite/roomserver
kegsay 1647213fac
Implement new RoomVersionImpl API (#3062)
As outlined in https://github.com/matrix-org/gomatrixserverlib/pull/368

The main change Dendrite side is that `RoomVersion` no longer has any
methods on it. Instead, you need to bounce via `gmsl.GetRoomVersion`.

It's very interesting to see where exactly Dendrite cares about this.
For some places it's creating events (fine) but others are way more
specific. Those areas will need to migrate to GMSL at some point.
2023-04-21 17:06:29 +01:00
..
acls refactor: update GMSL (#3058) 2023-04-19 15:50:33 +01:00
api refactor: update GMSL (#3058) 2023-04-19 15:50:33 +01:00
auth refactor: update GMSL (#3058) 2023-04-19 15:50:33 +01:00
internal Implement new RoomVersionImpl API (#3062) 2023-04-21 17:06:29 +01:00
producers Add RoomEventType nats.Header to avoid unneeded unmarshalling (#2765) 2022-10-05 12:12:42 +02:00
state Implement new RoomVersionImpl API (#3062) 2023-04-21 17:06:29 +01:00
storage Implement new RoomVersionImpl API (#3062) 2023-04-21 17:06:29 +01:00
types Refactor StoreEvent and create a new RoomDatabase interface (#2985) 2023-02-24 09:40:20 +01:00
version Implement new RoomVersionImpl API (#3062) 2023-04-21 17:06:29 +01:00
README.md use go module for dependencies (#594) 2019-05-21 21:56:55 +01:00
roomserver_test.go refactor: update GMSL (#3058) 2023-04-19 15:50:33 +01:00
roomserver.go Remove BaseDendrite (#3023) 2023-03-22 09:21:32 +01:00

RoomServer

RoomServer Internals

Numeric IDs

To save space matrix string identifiers are mapped to local numeric IDs. The numeric IDs are more efficient to manipulate and use less space to store. The numeric IDs are never exposed in the API the room server exposes. The numeric IDs are converted to string IDs before they leave the room server. The numeric ID for a string ID is never 0 to avoid being confused with go's default zero value. Zero is used to indicate that there was no corresponding string ID. Well-known event types and event state keys are preassigned numeric IDs.

State Snapshot Storage

The room server stores the state of the matrix room at each event. For efficiency the state is stored as blocks of 3-tuples of numeric IDs for the event type, event state key and event ID. For further efficiency the state snapshots are stored as the combination of up to 64 these blocks. This allows blocks of the room state to be reused in multiple snapshots.

The resulting database tables look something like this:

+-------------------------------------------------------------------+
| Events                                                            |
+---------+-------------------+------------------+------------------+
| EventNID| EventTypeNID      | EventStateKeyNID | StateSnapshotNID |
+---------+-------------------+------------------+------------------+
|       1 | m.room.create   1 | ""             1 | <nil>          0 |
|       2 | m.room.member   2 | "@user:foo"    2 | <nil>          0 |
|       3 | m.room.member   2 | "@user:bar"    3 | {1,2}          1 |
|       4 | m.room.message  3 | <nil>          0 | {1,2,3}        2 |
|       5 | m.room.member   2 | "@user:foo"    2 | {1,2,3}        2 |
|       6 | m.room.message  3 | <nil>          0 | {1,3,6}        3 |
+---------+-------------------+------------------+------------------+

+----------------------------------------+
| State Snapshots                        |
+-----------------------+----------------+
| EventStateSnapshotNID | StateBlockNIDs |
+-----------------------+----------------|
|                     1 |           {1}  |
|                     2 |         {1,2}  |
|                     3 |       {1,2,3}  |
+-----------------------+----------------+

+-----------------------------------------------------------------+
| State Blocks                                                    |
+---------------+-------------------+------------------+----------+
| StateBlockNID | EventTypeNID      | EventStateKeyNID | EventNID |
+---------------+-------------------+------------------+----------+
|             1 | m.room.create   1 | ""             1 |        1 |
|             1 | m.room.member   2 | "@user:foo"    2 |        2 |
|             2 | m.room.member   2 | "@user:bar"    3 |        3 |
|             3 | m.room.member   2 | "@user:foo"    2 |        6 |
+---------------+-------------------+------------------+----------+