dendrite/roomserver
Kegsay 737c83e0ae
roomserver: start refactoring storage layer (#1061)
* Begin refactoring out roomserver/storage/*/storage.go

* Convert event_types table
2020-05-26 15:42:42 +01:00
..
api Miscellaneous fixes (#1060) 2020-05-26 14:41:16 +01:00
auth Honour history_visibility when backfilling (#990) 2020-04-29 18:41:45 +01:00
internal Miscellaneous fixes (#1060) 2020-05-26 14:41:16 +01:00
state Fix #897 and shuffle directory around (#1054) 2020-05-21 14:40:13 +01:00
storage roomserver: start refactoring storage layer (#1061) 2020-05-26 15:42:42 +01:00
types Fix #897 and shuffle directory around (#1054) 2020-05-21 14:40:13 +01:00
version Enable v5 rooms (#992) 2020-04-29 19:37:00 +01:00
README.md use go module for dependencies (#594) 2019-05-21 21:56:55 +01:00
roomserver.go Separate muxes for public and internal APIs (#1056) 2020-05-22 11:43:17 +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 |
+---------------+-------------------+------------------+----------+