d5dbe546e4
* Always defer *sql.Rows.Close and consult with Err database/sql.Rows.Next() makes sure to call Close only after exhausting result rows which would NOT happen when returning early from a bad Scan. Close being idempotent makes it a great candidate to get always deferred regardless of what happens later on the result set. This change also makes sure call Err() after exhausting Next() and propagate non-nil results from it as the documentation advises. Closes #764 Signed-off-by: Kiril Vladimiroff <kiril@vladimiroff.org> * Override named result parameters in last returns Signed-off-by: Kiril Vladimiroff <kiril@vladimiroff.org> * Do the same over new changes that got merged Signed-off-by: Kiril Vladimiroff <kiril@vladimiroff.org> Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com> |
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|---|---|---|
| .. | ||
| alias | ||
| api | ||
| auth | ||
| input | ||
| query | ||
| state | ||
| storage | ||
| types | ||
| version | ||
| README.md | ||
| roomserver.go | ||
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 |
+---------------+-------------------+------------------+----------+