dendrite/roomserver
Till ad07b169b8
Refactor StoreEvent and create a new RoomDatabase interface (#2985)
This PR changes a few things:
- It pulls out the creation of several NIDs from the `StoreEvent`
function to make the functions more reusable
- Uses more caching when using those NIDs to avoid DB round trips
2023-02-24 09:40:20 +01:00
..
acls Pass pointers to events — reloaded (#1583) 2020-11-16 15:44:53 +00:00
api Merge keyserver & userapi (#2972) 2023-02-20 14:58:03 +01:00
auth Fix /get_missing_events for rooms with joined/invited history_visibility (#2787) 2022-10-11 16:04:02 +02:00
internal Refactor StoreEvent and create a new RoomDatabase interface (#2985) 2023-02-24 09:40:20 +01:00
producers Add RoomEventType nats.Header to avoid unneeded unmarshalling (#2765) 2022-10-05 12:12:42 +02:00
state Refactor StoreEvent and create a new RoomDatabase interface (#2985) 2023-02-24 09:40:20 +01:00
storage Refactor StoreEvent and create a new RoomDatabase interface (#2985) 2023-02-24 09:40:20 +01:00
types Refactor StoreEvent and create a new RoomDatabase interface (#2985) 2023-02-24 09:40:20 +01:00
version Change Default Room version to 10 (#2933) 2023-01-20 15:41:29 +01:00
README.md use go module for dependencies (#594) 2019-05-21 21:56:55 +01:00
roomserver.go Refactor StoreEvent and create a new RoomDatabase interface (#2985) 2023-02-24 09:40:20 +01:00
roomserver_test.go Merge keyserver & userapi (#2972) 2023-02-20 14:58:03 +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 |
+---------------+-------------------+------------------+----------+