Files
element-call-Github/src/state/CallViewModel/remoteMembers/Connection.ts
Timo K 63cd4f79dd fix playwright test! (It caught an actual bug!!! so the right wording
would be: fix implementation thanks to the playwright test!
2025-12-01 17:29:35 +01:00

246 lines
8.0 KiB
TypeScript

/*
Copyright 2025 Element Creations Ltd.
Copyright 2025 New Vector Ltd.
SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
Please see LICENSE in the repository root for full details.
*/
import {
connectedParticipantsObserver,
connectionStateObserver,
} from "@livekit/components-core";
import {
ConnectionError,
type ConnectionState as LivekitConenctionState,
type Room as LivekitRoom,
type LocalParticipant,
type RemoteParticipant,
RoomEvent,
} from "livekit-client";
import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
import { BehaviorSubject, map } from "rxjs";
import { type Logger } from "matrix-js-sdk/lib/logger";
import {
getSFUConfigWithOpenID,
type OpenIDClientParts,
type SFUConfig,
} from "../../../livekit/openIDSFU.ts";
import { type Behavior } from "../../Behavior.ts";
import { type ObservableScope } from "../../ObservableScope.ts";
import {
InsufficientCapacityError,
SFURoomCreationRestrictedError,
} from "../../../utils/errors.ts";
export type PublishingParticipant = LocalParticipant | RemoteParticipant;
export interface ConnectionOpts {
/** The media transport to connect to. */
transport: LivekitTransport;
/** The Matrix client to use for OpenID and SFU config requests. */
client: OpenIDClientParts;
/** The observable scope to use for this connection. */
scope: ObservableScope;
/** Optional factory to create the LiveKit room, mainly for testing purposes. */
livekitRoomFactory: () => LivekitRoom;
}
export type ConnectionState =
| { state: "Initialized" }
| { state: "FetchingConfig" }
| { state: "ConnectingToLkRoom" }
| {
state: "ConnectedToLkRoom";
livekitConnectionState$: Behavior<LivekitConenctionState>;
}
| { state: "FailedToStart"; error: Error }
| { state: "Stopped" };
/**
* A connection to a Matrix RTC LiveKit backend.
*
* Expose observables for participants and connection state.
*/
export class Connection {
// Private Behavior
private readonly _state$ = new BehaviorSubject<ConnectionState>({
state: "Initialized",
});
/**
* The current state of the connection to the media transport.
*/
public readonly state$: Behavior<ConnectionState> = this._state$;
/**
* The media transport to connect to.
*/
public readonly transport: LivekitTransport;
public readonly livekitRoom: LivekitRoom;
private scope: ObservableScope;
/**
* An observable of the participants that are publishing on this connection. (Excluding our local participant)
* This is derived from `participantsIncludingSubscribers$` and `remoteTransports$`.
* It filters the participants to only those that are associated with a membership that claims to publish on this connection.
*/
public readonly remoteParticipantsWithTracks$: Behavior<
PublishingParticipant[]
>;
/**
* Whether the connection has been stopped.
* @see Connection.stop
* */
protected stopped = false;
/**
* Starts the connection.
*
* This will:
* 1. Request an OpenId token `request_token` (allows matrix users to verify their identity with a third-party service.)
* 2. Use this token to request the SFU config to the MatrixRtc authentication service.
* 3. Connect to the configured LiveKit room.
*
* The errors are also represented as a state in the `state$` observable.
* It is safe to ignore those errors and handle them accordingly via the `state$` observable.
* @throws {InsufficientCapacityError} if the LiveKit server indicates that it has insufficient capacity to accept the connection.
* @throws {SFURoomCreationRestrictedError} if the LiveKit server indicates that the room does not exist and cannot be created.
*/
// TODO consider an autostart pattern...
public async start(): Promise<void> {
this.logger.debug("Starting Connection");
this.stopped = false;
try {
this._state$.next({
state: "FetchingConfig",
});
const { url, jwt } = await this.getSFUConfigWithOpenID();
// If we were stopped while fetching the config, don't proceed to connect
if (this.stopped) return;
this._state$.next({
state: "ConnectingToLkRoom",
});
try {
await this.livekitRoom.connect(url, jwt);
} catch (e) {
// LiveKit uses 503 to indicate that the server has hit its track limits.
// https://github.com/livekit/livekit/blob/fcb05e97c5a31812ecf0ca6f7efa57c485cea9fb/pkg/service/rtcservice.go#L171
// It also errors with a status code of 200 (yes, really) for room
// participant limits.
// LiveKit Cloud uses 429 for connection limits.
// Either way, all these errors can be explained as "insufficient capacity".
if (e instanceof ConnectionError) {
if (e.status === 503 || e.status === 200 || e.status === 429) {
throw new InsufficientCapacityError();
}
if (e.status === 404) {
// error msg is "Could not establish signal connection: requested room does not exist"
// The room does not exist. There are two different modes of operation for the SFU:
// - the room is created on the fly when connecting (livekit `auto_create` option)
// - Only authorized users can create rooms, so the room must exist before connecting (done by the auth jwt service)
// In the first case there will not be a 404, so we are in the second case.
throw new SFURoomCreationRestrictedError();
}
}
throw e;
}
// If we were stopped while connecting, don't proceed to update state.
if (this.stopped) return;
this._state$.next({
state: "ConnectedToLkRoom",
livekitConnectionState$: this.scope.behavior(
connectionStateObserver(this.livekitRoom),
),
});
} catch (error) {
this.logger.debug(`Failed to connect to LiveKit room: ${error}`);
this._state$.next({
state: "FailedToStart",
error: error instanceof Error ? error : new Error(`${error}`),
});
throw error;
}
}
protected async getSFUConfigWithOpenID(): Promise<SFUConfig> {
return await getSFUConfigWithOpenID(
this.client,
this.transport.livekit_service_url,
this.transport.livekit_alias,
);
}
/**
* Stops the connection.
*
* This will disconnect from the LiveKit room.
* If the connection is already stopped, this is a no-op.
*/
public async stop(): Promise<void> {
this.logger.debug(
`Stopping connection to ${this.transport.livekit_service_url}`,
);
if (this.stopped) return;
await this.livekitRoom.disconnect();
this._state$.next({
state: "Stopped",
});
this.stopped = true;
}
private readonly client: OpenIDClientParts;
private readonly logger: Logger;
/**
* Creates a new connection to a matrix RTC LiveKit backend.
*
* @param opts - Connection options {@link ConnectionOpts}.
*
* @param logger
*/
public constructor(opts: ConnectionOpts, logger: Logger) {
this.logger = logger.getChild("[Connection]");
this.logger.info(
`[Connection] Creating new connection to ${opts.transport.livekit_service_url} ${opts.transport.livekit_alias}`,
);
const { transport, client, scope } = opts;
this.scope = scope;
this.livekitRoom = opts.livekitRoomFactory();
this.transport = transport;
this.client = client;
// REMOTE participants with track!!!
// this.remoteParticipantsWithTracks$
this.remoteParticipantsWithTracks$ = scope.behavior(
// only tracks remote participants
connectedParticipantsObserver(this.livekitRoom, {
additionalRoomEvents: [
RoomEvent.TrackPublished,
RoomEvent.TrackUnpublished,
],
}).pipe(
map((participants) => {
return participants.filter(
(participant) => participant.getTrackPublications().length > 0,
);
}),
),
[],
);
scope.onEnd(() => {
this.logger.info(`Connection scope ended, stopping connection`);
void this.stop();
});
}
}