Files
element-call-Github/src/state/SessionBehaviors.ts
2025-11-14 10:44:16 +01:00

82 lines
2.3 KiB
TypeScript

/*
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 {
type CallMembership,
isLivekitTransport,
type LivekitTransport,
type MatrixRTCSession,
MatrixRTCSessionEvent,
} from "matrix-js-sdk/lib/matrixrtc";
import { fromEvent } from "rxjs";
import {
Epoch,
mapEpoch,
trackEpoch,
type ObservableScope,
} from "./ObservableScope";
import { type Behavior } from "./Behavior";
export const membershipsAndTransports$ = (
scope: ObservableScope,
memberships$: Behavior<Epoch<CallMembership[]>>,
): {
membershipsWithTransport$: Behavior<
Epoch<{ membership: CallMembership; transport?: LivekitTransport }[]>
>;
transports$: Behavior<Epoch<LivekitTransport[]>>;
} => {
/**
* Lists the transports used by ourselves, plus all other MatrixRTC session
* members. For completeness this also lists the preferred transport and
* whether we are in multi-SFU mode or sticky events mode (because
* advertisedTransport$ wants to read them at the same time, and bundling data
* together when it might change together is what you have to do in RxJS to
* avoid reading inconsistent state or observing too many changes.)
*/
const membershipsWithTransport$ = scope.behavior(
memberships$.pipe(
mapEpoch((memberships) => {
return memberships.map((membership) => {
const oldestMembership = memberships[0] ?? membership;
const transport = membership.getTransport(oldestMembership);
return {
membership,
transport: isLivekitTransport(transport) ? transport : undefined,
};
});
}),
),
);
const transports$ = scope.behavior(
membershipsWithTransport$.pipe(
mapEpoch((mts) => mts.flatMap(({ transport: t }) => (t ? [t] : []))),
),
);
return {
membershipsWithTransport$,
transports$,
};
};
export const createMemberships$ = (
scope: ObservableScope,
matrixRTCSession: MatrixRTCSession,
): Behavior<Epoch<CallMembership[]>> => {
return scope.behavior(
fromEvent(
matrixRTCSession,
MatrixRTCSessionEvent.MembershipsChanged,
(_, memberships: CallMembership[]) => memberships,
).pipe(trackEpoch()),
new Epoch(matrixRTCSession.memberships),
);
};