Add notes on what message sending will look like in dendrite
MODIFY
README.md
README.md
@@ -62,38 +62,119 @@ so that the readers can avoid querying the room server unnecessarily.
[This architecture can be extended to cover most of the APIs.](WIRING.md)
+## How things are supposed to work.
+
+### Local client sends an event in an existing room.
+
+ 0) The client sends a PUT `/_matrix/client/r0/rooms/{roomId}/send` request
+ and an HTTP loadbalancer routes the request to a ClientAPI.
+
+ 1) The ClientAPI:
+
+ * Authenticates the local user using the `access_token` sent in the HTTP
+ request.
+ * Checks if it has already processed or is processing a request with the
+ same `txnID`.
+ * Calculates which state events are needed to auth the request.
+ * Queries the necessary state events and the latest events in the room
+ from the RoomServer.
+ * Confirms that the room exists and checks whether the event is allowed by
+ the auth checks.
+ * Builds and signs the events.
+ * Writes the event to a "InputRoomEvent" kafka topic.
+ * Send a `200 OK` response to the client.
+
+ 2) The RoomServer reads the event from "InputRoomEvent" kafka topic:
+
+ * Checks if it has already has a copy of the event.
+ * Checks if the event is allowed by the auth checks using the auth events
+ at the event.
+ * Calculates the room state at the event.
+ * Works out what the latest events in the room after processing this event
+ are.
+ * Calculate how the changes in the latest events affect the current state
+ of the room.
+ * TODO: Workout what events determine the visibility of this event to other
+ users
+ * Writes the event along with the changes in current state to an
+ "OutputRoomEvent" kafka topic. It writes all the events for a room to
+ the same kafka partition.
+
+ 3a) The ClientSync reads the event from the "OutputRoomEvent" kafka topic:
+
+ * Updates its copy of the current state for the room.
+ * Works out which users need to be notified about the event.
+ * Wakes up any pending `/_matrix/client/r0/sync` requests for those users.
+ * Adds the event to the recent timeline events for the room.
+
+ 3b) The FederationSender reads the event from the "OutputRoomEvent" kafka topic:
+
+ * Updates its copy of the current state for the room.
+ * Works out which remote servers need to be notified about the event.
+ * Sends a `/_matrix/federation/v1/send` request to those servers.
+ * Or if there is a request in progress then add the event to a queue to be
+ sent when the previous request finishes.
+
+### Remote server sends an event in an existing room.
+
+ 0) The remote server sends a `PUT /_matrix/federation/v1/send` request and an
+ HTTP loadbalancer routes the request to a FederationReceiver.
+
+ 1) The FederationReceiver:
+
+ * Authenticates the remote server using the "X-Matrix" authorisation header.
+ * Checks if it has already processed or is processing a request with the
+ same `txnID`.
+ * Checks the signatures for the events.
+ Fetches the ed2519 keys for the event senders if necessary.
+ * Queries the RoomServer for a copy of the state of the room at each event.
+ * If the RoomServer doesn't know the state of the room at an event then
+ query the state of the room at the event from the remote server using
+ `GET /_matrix/federation/v1/state_ids` falling back to
+ `GET /_matrix/federation/v1/state` if necessary.
+ * Once the state at each event is known check whether the events are
+ allowed by the auth checks against the state at each event.
+ * For each event that is allowed write the event to the "InputRoomEvent"
+ kafka topic.
+ * Send a 200 OK response to the remote server listing which events were
+ successfully processed and which events failed
+
+ 2) The RoomServer processes the event the same as it would a local event.
+
+ 3a) The ClientSync processes the event the same as it would a local event.
+
# TODO
- [ ] gomatrixlib
- [x] Canonical JSON.
- [x] Signed JSON.
- - [ ] Event hashing.
- - [ ] Event signing.
+ - [x] Event hashing.
+ - [x] Event signing.
- [x] Federation server discovery.
- [x] Federation key lookup.
- [ ] Federation request signing.
- [x] Event authentication.
- [ ] Event visibility.
- - [ ] State resolution.
+ - [x] State resolution.
- [ ] Third party invites authentication.
- [ ] Room Server
- - [ ] Inputing new events from logs.
- - [ ] Inputing backfilled events from logs.
- - [ ] Outputing events and current state to logs.
+ - [x] Inputting new events from logs.
+ - [ ] Inputting back-filled events from logs.
+ - [x] Outputting events and current state to logs.
- [ ] Querying state at an event.
- - [ ] Querying current forward extremities and state.
+ - [x] Querying current forward extremities and state.
- [ ] Querying message history.
- [ ] Exporting/importing messages from other servers.
- [ ] Other Room Server stuff.
- [ ] Client Room Send
- - [ ] Handling /client/r0/room/... HTTP PUTs
+ - [x] Handling /client/r0/room/... HTTP PUTs
- [ ] Talk to remote servers for joins to remote servers.
- - [ ] Outputting new events to logs.
+ - [x] Outputting new events to logs.
- [ ] Updating the last active time in presence.
- [ ] Other Client Room Send stuff.
- [ ] Client Sync
- - [ ] Inputing new room events and state from the logs.
+ - [ ] Inputting new room events and state from the logs.
- [ ] Handling /client/r0/sync HTTP GETs
- - [ ] Outputing whether the client is syncing to the logs.
+ - [ ] Outputting whether the client is syncing to the logs.
- [ ] Other Client Sync Stuff.
- [ ] Other Components.

MODIFY
WIRING.md
WIRING.md
@@ -20,7 +20,7 @@ Diagram:
+----------| W | +----------| S | +--------| R |
| +---+ | Receipts +---+ | Client +---+
| Federation |>=========================================>| Server |>=====================>| Sync |
- | Send | | | | |
+ | Receiver | | | | |
| | +---+ | | | |
| | +--------| W | | | | |
| | | Client +---+ | | | |
@@ -49,8 +49,8 @@ Diagram:
| | +---+ | | +---+ | |
| | +--------| W | | | +----------| S | | |
| | | Client +---+ | | | Presence +---+ | |
- | | | Room |>=====>| |>=====>| Server |>=====================>| |
- | | | Send | +--------+ | | | |
+ | | | API |>=====>| |>=====>| Server |>=====================>| |
+ | | | /send | +--------+ | | | |
| | | | | | | |
| | | |>======================>| |<=====================<| |
| | +----------+ | | | |
@@ -101,7 +101,7 @@ choke-point to implement ratelimiting and backoff correctly.
* Writes typing updates to logs.
* Writes other updates to logs.
-## Client Room Send
+## Client API /send
* Handles puts to `/client/v1/rooms/` that create room events.
* Queries information needed to process events from the Room Server.

Add notes on what message sending will look like in dendrite (#45)