From c6dee2da0919038b49398be4c3a60f9a36358036 Mon Sep 17 00:00:00 2001
From: Laura Hausmann <laura@hausmann.dev>
Date: Tue, 5 Sep 2023 20:15:23 +0200
Subject: [PATCH] Purge deleted users from user lookup caches

---
 .../src/queue/processors/db/delete-account.ts |  3 +++
 .../backend/src/server/api/stream/types.ts    |  6 ++++++
 packages/backend/src/services/user-cache.ts   | 21 +++++++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/packages/backend/src/queue/processors/db/delete-account.ts b/packages/backend/src/queue/processors/db/delete-account.ts
index adb93484b..cca7750cf 100644
--- a/packages/backend/src/queue/processors/db/delete-account.ts
+++ b/packages/backend/src/queue/processors/db/delete-account.ts
@@ -8,6 +8,7 @@ import { MoreThan } from "typeorm";
 import { deleteFileSync } from "@/services/drive/delete-file.js";
 import { sendEmail } from "@/services/send-email.js";
 import meilisearch from "@/db/meilisearch.js";
+import { publishInternalEvent } from "@/services/stream.js";
 
 const logger = queueLogger.createSubLogger("delete-account");
 
@@ -18,6 +19,7 @@ export async function deleteAccount(
 
 	const user = await Users.findOneBy({ id: job.data.user.id });
 	if (!user) return;
+	const isLocal = Users.isLocalUser(user);
 
 	{
 		// Delete notes
@@ -98,6 +100,7 @@ export async function deleteAccount(
 		// nop
 	} else {
 		await Users.delete(job.data.user.id);
+		publishInternalEvent(isLocal ? "localUserDeleted" : "remoteUserDeleted", { id: user.id });
 	}
 
 	return "Account deleted";
diff --git a/packages/backend/src/server/api/stream/types.ts b/packages/backend/src/server/api/stream/types.ts
index 91095a46d..601c56f41 100644
--- a/packages/backend/src/server/api/stream/types.ts
+++ b/packages/backend/src/server/api/stream/types.ts
@@ -38,9 +38,15 @@ export interface InternalStreamTypes {
 	localUserUpdated: {
 		id: User["id"];
 	};
+	localUserDeleted: {
+		id: User["id"];
+	};
 	remoteUserUpdated: {
 		id: User["id"];
 	};
+	remoteUserDeleted: {
+		id: User["id"];
+	};
 	webhookCreated: Webhook;
 	webhookDeleted: Webhook;
 	webhookUpdated: Webhook;
diff --git a/packages/backend/src/services/user-cache.ts b/packages/backend/src/services/user-cache.ts
index ed700185d..a5e12e34a 100644
--- a/packages/backend/src/services/user-cache.ts
+++ b/packages/backend/src/services/user-cache.ts
@@ -27,6 +27,19 @@ subscriber.on("message", async (_, data) => {
 	if (obj.channel === "internal") {
 		const { type, body } = obj.message;
 		switch (type) {
+			case "localUserDeleted": {
+				await userByIdCache.delete(body.id);
+				await localUserByIdCache.delete(body.id);
+				const toDelete = Array.from(await localUserByNativeTokenCache.getAll())
+					.filter((v) => v[1]?.id === body.id)
+					.map((v) => v[0]);
+				await localUserByNativeTokenCache.delete(...toDelete);
+				const uriCacheToDelete = Array.from(await uriPersonCache.getAll())
+					.filter((v) => v[1]?.id === body.id)
+					.map((v) => v[0]);
+				await uriPersonCache.delete(...uriCacheToDelete);
+				break;
+			}
 			case "localUserUpdated": {
 				await userByIdCache.delete(body.id);
 				await localUserByIdCache.delete(body.id);
@@ -55,6 +68,14 @@ subscriber.on("message", async (_, data) => {
 				}
 				break;
 			}
+			case "remoteUserDeleted": {
+				await userByIdCache.delete(body.id);
+				const toDelete = Array.from(await uriPersonCache.getAll())
+					.filter((v) => v[1]?.id === body.id)
+					.map((v) => v[0]);
+				await uriPersonCache.delete(...toDelete);
+				break;
+			}
 			case "userTokenRegenerated": {
 				const user = (await Users.findOneByOrFail({
 					id: body.id,