matrix-org.dendrite/roomserver
kegsay f5b3144dc3
Use PDU not *Event in HeaderedEvent (#3073)
Requires https://github.com/matrix-org/gomatrixserverlib/pull/376

This has numerous upsides:
 - Less type casting to `*Event` is required.
- Making Dendrite work with `PDU` interfaces means we can swap out Event
impls more easily.
 - Tests which represent weird event shapes are easier to write.

Part of a series of refactors on GMSL.
2023-05-02 15:03:16 +01:00
..
acls Use PDU not *Event in HeaderedEvent (#3073) 2023-05-02 15:03:16 +01:00
api Use PDU not *Event in HeaderedEvent (#3073) 2023-05-02 15:03:16 +01:00
auth Use PDU not *Event in HeaderedEvent (#3073) 2023-05-02 15:03:16 +01:00
internal Use PDU not *Event in HeaderedEvent (#3073) 2023-05-02 15:03:16 +01:00
producers Use PDU not *Event in HeaderedEvent (#3073) 2023-05-02 15:03:16 +01:00
state Use PDU not *Event in HeaderedEvent (#3073) 2023-05-02 15:03:16 +01:00
storage Use PDU not *Event in HeaderedEvent (#3073) 2023-05-02 15:03:16 +01:00
types Use PDU not *Event in HeaderedEvent (#3073) 2023-05-02 15:03:16 +01:00
version Use IRoomVersion (#3064) 2023-04-24 11:50:37 +01:00
README.md use go module for dependencies (#594) 2019-05-21 21:56:55 +01:00
roomserver.go Remove `BaseDendrite` (#3023) 2023-03-22 09:21:32 +01:00
roomserver_test.go Use PDU not *Event in HeaderedEvent (#3073) 2023-05-02 15:03:16 +01:00

README.md

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 |
+---------------+-------------------+------------------+----------+