mirror of
https://github.com/hoernschen/dendrite.git
synced 2024-12-27 07:28:27 +00:00
102 lines
4.1 KiB
Markdown
102 lines
4.1 KiB
Markdown
# Dendrite
|
|
|
|
Dendrite will be a matrix homeserver written in go.
|
|
|
|
# Design
|
|
|
|
*
|
|
|
|
|
|
## Log Based Architecture
|
|
|
|
### Decomposition and Decoupling
|
|
|
|
A matrix homeserver can be built around append-only event logs built from the
|
|
messages, receipts, presence, typing notifications, device messages and other
|
|
events sent by users on the homeservers or by other homeservers.
|
|
|
|
The server would then decompose into two categories: writers that add new
|
|
entries to the logs and readers that read those entries.
|
|
|
|
The event logs then serve to decouple the two components, the writers and
|
|
readers need only agree on the format of the entries in the event log.
|
|
This format could be largely derived from the wire format of the events used
|
|
in the client and federation protocols:
|
|
|
|
|
|
C-S API +---------+ Event Log +---------+ C-S API
|
|
---------> | |+ (e.g. kafka) | |+ --------->
|
|
| Writers || =============> | Readers ||
|
|
---------> | || | || --------->
|
|
S-S API +---------+| +---------+| S-S API
|
|
+---------+ +---------+
|
|
|
|
However the way matrix handles state events in a room creates a few
|
|
complications for this model.
|
|
|
|
1) Writers require the room state at an event to check if it is allowed.
|
|
2) Readers require the room state at an event to determine the users and
|
|
servers that are allowed to see the event.
|
|
3) A client can query the current state of the room from a reader.
|
|
|
|
The writers and readers cannot extract the necessary information directly from
|
|
the event logs because it would take to long to extract the information as the
|
|
state is built up by collecting individual state events from the event history.
|
|
|
|
The writers and readers therefore need access to something that stores copies
|
|
of the event state in a form that can be efficiently queried. One possibility
|
|
would be for the readers and writers to maintain copies of the current state
|
|
in local databases. A second possibility would be to add a dedicated component
|
|
that maintained the state of the room and exposed an API that the readers and
|
|
writers could query to get the state. The second has the advantage that the
|
|
state is calculated and stored in a single location.
|
|
|
|
|
|
C-S API +---------+ Log +--------+ Log +---------+ C-S API
|
|
---------> | |+ ======> | | ======> | |+ --------->
|
|
| Writers || | Room | | Readers ||
|
|
---------> | || <------ | Server | ------> | || --------->
|
|
S-S API +---------+| Query | | Query +---------+| S-S API
|
|
+---------+ +--------+ +---------+
|
|
|
|
|
|
The room server can annotate the events it logs to the readers with room state
|
|
so that the readers can avoid querying the room server unnecessarily.
|
|
|
|
[This architecture can be extended to cover most of the APIs.](WIRING.md)
|
|
|
|
# TODO
|
|
|
|
- [ ] gomatrixlib
|
|
- [x] Canonical JSON.
|
|
- [x] Signed JSON.
|
|
- [ ] Event hashing.
|
|
- [ ] Event signing.
|
|
- [x] Federation server discovery.
|
|
- [x] Federation key lookup.
|
|
- [ ] Federation request signing.
|
|
- [x] Event authentication.
|
|
- [ ] Event visibility.
|
|
- [ ] 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.
|
|
- [ ] Querying state at an event.
|
|
- [ ] 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
|
|
- [ ] Talk to remote servers for joins to remote servers.
|
|
- [ ] 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.
|
|
- [ ] Handling /client/r0/sync HTTP GETs
|
|
- [ ] Outputing whether the client is syncing to the logs.
|
|
- [ ] Other Client Sync Stuff.
|
|
- [ ] Other Components.
|