dendrite/roomserver
kegsay 3e50bac944
bugfix: order the state blocks so recreating state snapshots works correctly (#1908)
* Logging

* Revert "Logging"

This reverts commit 23ce334182d8a70f8e0381786f9dea77a9b91ed8.

* bugfix: order the state blocks so recreating state snapshots works correctly
2021-07-09 10:49:49 +01:00
..
acls Pass pointers to events — reloaded (#1583) 2020-11-16 15:44:53 +00:00
api Fix appsevice alias queries part 2 (#1684) 2021-03-03 17:00:31 +00:00
auth Pass pointers to events — reloaded (#1583) 2020-11-16 15:44:53 +00:00
internal Fix bug when rejecting invites (#1907) 2021-07-08 14:54:03 +01:00
inthttp Peeking over federation via MSC2444 (#1391) 2021-01-22 14:55:08 +00:00
state Increase gocyclo complexity to 25 (and remove all but 2 golint directives related to it) (#1783) 2021-03-03 14:35:57 +00:00
storage bugfix: order the state blocks so recreating state snapshots works correctly (#1908) 2021-07-09 10:49:49 +01:00
types State storage refactor (#1839) 2021-04-26 13:25:57 +01:00
version Set default room version to v6 (#1438) 2020-09-25 12:59:57 +01:00
README.md use go module for dependencies (#594) 2019-05-21 21:56:55 +01:00
roomserver_test.go Top-level setup package (#1605) 2020-12-02 17:41:00 +00:00
roomserver.go Top-level setup package (#1605) 2020-12-02 17:41:00 +00:00

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