dendrite/roomserver
Neil Alexander 5106cc807c
Ensure only one transaction is used for RS input per room (#2178)
* Ensure the input API only uses a single transaction

* Remove more of the dead query API call

* Tidy up

* Fix tests hopefully

* Don't do unnecessary work for rooms that don't exist

* Improve error, fix another case where transaction wasn't used properly

* Add a unit test for checking single transaction on RS input API

* Fix logic oops when deciding whether to use a transaction in storeEvent
2022-02-11 17:40:14 +00:00
..
acls Pass pointers to events — reloaded (#1583) 2020-11-16 15:44:53 +00:00
api Ensure only one transaction is used for RS input per room (#2178) 2022-02-11 17:40:14 +00:00
auth Pass pointers to events — reloaded (#1583) 2020-11-16 15:44:53 +00:00
internal Ensure only one transaction is used for RS input per room (#2178) 2022-02-11 17:40:14 +00:00
inthttp Ensure only one transaction is used for RS input per room (#2178) 2022-02-11 17:40:14 +00:00
state Full roomserver input transactional isolation (#2141) 2022-02-04 10:39:34 +00:00
storage Ensure only one transaction is used for RS input per room (#2178) 2022-02-11 17:40:14 +00:00
types Fix fetching missing state (#2163) 2022-02-10 10:05:14 +00:00
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.go Remove sarama/saramajetstream dependencies (#2138) 2022-02-04 13:08:13 +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 |
+---------------+-------------------+------------------+----------+