1 files changed, 77 insertions, 0 deletions
diff --git a/includes/external/matrix/node_modules/matrix-js-sdk/src/rust-crypto/KeyClaimManager.ts b/includes/external/matrix/node_modules/matrix-js-sdk/src/rust-crypto/KeyClaimManager.ts
new file mode 100644
index 0000000..9df8f89
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+++ b/includes/external/matrix/node_modules/matrix-js-sdk/src/rust-crypto/KeyClaimManager.ts
@@ -0,0 +1,77 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { OlmMachine, UserId } from "@matrix-org/matrix-sdk-crypto-js";
+
+import { OutgoingRequestProcessor } from "./OutgoingRequestProcessor";
+
+/**
+ * KeyClaimManager: linearises calls to OlmMachine.getMissingSessions to avoid races
+ *
+ * We have one of these per `RustCrypto` (and hence per `MatrixClient`).
+ */
+export class KeyClaimManager {
+    private currentClaimPromise: Promise<void>;
+    private stopped = false;
+
+    public constructor(
+        private readonly olmMachine: OlmMachine,
+        private readonly outgoingRequestProcessor: OutgoingRequestProcessor,
+    ) {
+        this.currentClaimPromise = Promise.resolve();
+    }
+
+    /**
+     * Tell the KeyClaimManager to immediately stop processing requests.
+     *
+     * Any further calls, and any still in the queue, will fail with an error.
+     */
+    public stop(): void {
+        this.stopped = true;
+    }
+
+    /**
+     * Given a list of users, attempt to ensure that we have Olm Sessions active with each of their devices
+     *
+     * If we don't have an active olm session, we will claim a one-time key and start one.
+     *
+     * @param userList - list of userIDs to claim
+     */
+    public ensureSessionsForUsers(userList: Array<UserId>): Promise<void> {
+        // The Rust-SDK requires that we only have one getMissingSessions process in flight at once. This little dance
+        // ensures that, by only having one call to ensureSessionsForUsersInner active at once (and making them
+        // queue up in order).
+        const prom = this.currentClaimPromise
+            .catch(() => {
+                // any errors in the previous claim will have been reported already, so there is nothing to do here.
+                // we just throw away the error and start anew.
+            })
+            .then(() => this.ensureSessionsForUsersInner(userList));
+        this.currentClaimPromise = prom;
+        return prom;
+    }
+
+    private async ensureSessionsForUsersInner(userList: Array<UserId>): Promise<void> {
+        // bail out quickly if we've been stopped.
+        if (this.stopped) {
+            throw new Error(`Cannot ensure Olm sessions: shutting down`);
+        }
+        const claimRequest = await this.olmMachine.getMissingSessions(userList);
+        if (claimRequest) {
+            await this.outgoingRequestProcessor.makeOutgoingRequest(claimRequest);
+        }
+    }
+}