From 34dcb1c51cac8449db90699227497052135486b8 Mon Sep 17 00:00:00 2001
From: Hazelnoot <acomputerdog@gmail.com>
Date: Fri, 4 Jul 2025 09:53:06 -0400
Subject: [PATCH] optimize i/update-remote-user endpoint by fetching from cache

---
 packages/backend/src/core/CacheService.ts      | 13 ++++++++++++-
 .../endpoints/federation/update-remote-user.ts | 18 +++++++++++++++++-
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/packages/backend/src/core/CacheService.ts b/packages/backend/src/core/CacheService.ts
index 7ba1aba1bc..c29a3ecd7e 100644
--- a/packages/backend/src/core/CacheService.ts
+++ b/packages/backend/src/core/CacheService.ts
@@ -9,7 +9,7 @@ import { In, IsNull } from 'typeorm';
 import type { BlockingsRepository, FollowingsRepository, MutingsRepository, RenoteMutingsRepository, MiUserProfile, UserProfilesRepository, UsersRepository, MiNote, MiFollowing, NoteThreadMutingsRepository } from '@/models/_.js';
 import { MemoryKVCache, RedisKVCache } from '@/misc/cache.js';
 import { QuantumKVCache } from '@/misc/QuantumKVCache.js';
-import type { MiLocalUser, MiUser } from '@/models/User.js';
+import type { MiLocalUser, MiRemoteUser, MiUser } from '@/models/User.js';
 import { DI } from '@/di-symbols.js';
 import { UserEntityService } from '@/core/entities/UserEntityService.js';
 import { bindThis } from '@/decorators.js';
@@ -387,6 +387,17 @@ export class CacheService implements OnApplicationShutdown {
 		}) ?? null;
 	}
 
+	@bindThis
+	public async findRemoteUserById(userId: MiUser['id']): Promise<MiRemoteUser | null> {
+		const user = await this.findUserById(userId);
+
+		if (user.host == null) {
+			return null;
+		}
+
+		return user as MiRemoteUser;
+	}
+
 	@bindThis
 	public async getFollowStats(userId: MiUser['id']): Promise<FollowStats> {
 		return await this.userFollowStatsCache.fetch(userId, async () => {
diff --git a/packages/backend/src/server/api/endpoints/federation/update-remote-user.ts b/packages/backend/src/server/api/endpoints/federation/update-remote-user.ts
index 67fa5ed343..27c3e63ade 100644
--- a/packages/backend/src/server/api/endpoints/federation/update-remote-user.ts
+++ b/packages/backend/src/server/api/endpoints/federation/update-remote-user.ts
@@ -7,12 +7,22 @@ import { Injectable } from '@nestjs/common';
 import { Endpoint } from '@/server/api/endpoint-base.js';
 import { ApPersonService } from '@/core/activitypub/models/ApPersonService.js';
 import { GetterService } from '@/server/api/GetterService.js';
+import { CacheService } from '@/core/CacheService.js';
+import { ApiError } from '@/server/api/error.js';
 
 export const meta = {
 	tags: ['federation'],
 
 	requireCredential: false,
 
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '558ea170-f653-4700-94d0-5a818371d0df',
+		},
+	},
+
 	// Up to 10 calls, then 4 / second.
 	// This allows for reliable automation.
 	limit: {
@@ -35,9 +45,15 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 	constructor(
 		private getterService: GetterService,
 		private apPersonService: ApPersonService,
+		private readonly cacheService: CacheService,
 	) {
 		super(meta, paramDef, async (ps) => {
-			const user = await this.getterService.getRemoteUser(ps.userId);
+			const user = await this.cacheService.findRemoteUserById(ps.userId);
+
+			if (!user) {
+				throw new ApiError(meta.errors.noSuchUser);
+			}
+
 			await this.apPersonService.updatePerson(user.uri!);
 		});
 	}