From 51386722320f6cd1351d1508023bb59b3598ca01 Mon Sep 17 00:00:00 2001
From: KOBA789 <kobahide789@gmail.com>
Date: Mon, 16 Sep 2024 20:07:45 +0900
Subject: [PATCH] perf(backend): Defer instance metadata update (#727)

---
 .../backend/src/core/NoteCreateService.ts     | 15 +++++++++++-
 packages/backend/src/misc/collapsed-queue.ts  | 24 +++++++++++++++++++
 .../queue/processors/InboxProcessorService.ts | 22 +++++++++++++----
 3 files changed, 56 insertions(+), 5 deletions(-)
 create mode 100644 packages/backend/src/misc/collapsed-queue.ts

diff --git a/packages/backend/src/core/NoteCreateService.ts b/packages/backend/src/core/NoteCreateService.ts
index cfe428c9e..d16ebac2a 100644
--- a/packages/backend/src/core/NoteCreateService.ts
+++ b/packages/backend/src/core/NoteCreateService.ts
@@ -59,6 +59,7 @@ import { isReply } from '@/misc/is-reply.js';
 import { trackPromise } from '@/misc/promise-tracker.js';
 import { isNotNull } from '@/misc/is-not-null.js';
 import { IdentifiableError } from '@/misc/identifiable-error.js';
+import { CollapsedQueue } from '@/misc/collapsed-queue.js';
 
 type NotificationType = 'reply' | 'renote' | 'quote' | 'mention';
 
@@ -150,6 +151,7 @@ type Option = {
 export class NoteCreateService implements OnApplicationShutdown {
 	private logger: Logger;
 	#shutdownController = new AbortController();
+	private updateNotesCountQueue: CollapsedQueue<MiNote['id'], number>;
 
 	constructor(
 		@Inject(DI.config)
@@ -217,6 +219,7 @@ export class NoteCreateService implements OnApplicationShutdown {
 		private loggerService: LoggerService,
 	) {
 		this.logger = this.loggerService.getLogger('note:create');
+		this.updateNotesCountQueue = new CollapsedQueue(60 * 1000 * 5, this.collapseNotesCount, this.performUpdateNotesCount);
 	}
 
 	@bindThis
@@ -548,7 +551,7 @@ export class NoteCreateService implements OnApplicationShutdown {
 		// Register host
 		if (this.userEntityService.isRemoteUser(user)) {
 			this.federatedInstanceService.fetch(user.host).then(async i => {
-				this.instancesRepository.increment({ id: i.id }, 'notesCount', 1);
+				this.updateNotesCountQueue.enqueue(i.id, 1);
 				if ((await this.metaService.fetch()).enableChartsForFederatedInstances) {
 					this.instanceChart.updateNote(i.host, note, true);
 				}
@@ -1092,6 +1095,16 @@ export class NoteCreateService implements OnApplicationShutdown {
 		);
 	}
 
+	@bindThis
+	private collapseNotesCount(oldValue: number, newValue: number) {
+		return oldValue + newValue;
+	}
+
+	@bindThis
+	private performUpdateNotesCount(id: MiNote['id'], incrBy: number) {
+		this.instancesRepository.increment({ id: id }, 'notesCount', incrBy);
+	}
+
 	@bindThis
 	public dispose(): void {
 		this.#shutdownController.abort();
diff --git a/packages/backend/src/misc/collapsed-queue.ts b/packages/backend/src/misc/collapsed-queue.ts
new file mode 100644
index 000000000..731ff58d2
--- /dev/null
+++ b/packages/backend/src/misc/collapsed-queue.ts
@@ -0,0 +1,24 @@
+export class CollapsedQueue<K, V> {
+	private jobs: Map<K, V> = new Map();
+
+	constructor(
+		private timeout: number,
+		private collapse: (oldValue: V, newValue: V) => V,
+		private doJob: (key: K, value: V) => void,
+	) { }
+
+	enqueue(key: K, value: V) {
+		if (this.jobs.has(key)) {
+			const old = this.jobs.get(key)!;
+			const merged = this.collapse(old, value);
+			this.jobs.set(key, merged);
+		} else {
+			this.jobs.set(key, value);
+			setTimeout(() => {
+				const value = this.jobs.get(key)!;
+				this.jobs.delete(key);
+				this.doJob(key, value);
+			}, this.timeout);
+		}
+	}
+}
diff --git a/packages/backend/src/queue/processors/InboxProcessorService.ts b/packages/backend/src/queue/processors/InboxProcessorService.ts
index be800bef4..e87a29b54 100644
--- a/packages/backend/src/queue/processors/InboxProcessorService.ts
+++ b/packages/backend/src/queue/processors/InboxProcessorService.ts
@@ -28,10 +28,13 @@ import { bindThis } from '@/decorators.js';
 import { IdentifiableError } from '@/misc/identifiable-error.js';
 import { QueueLoggerService } from '../QueueLoggerService.js';
 import type { InboxJobData } from '../types.js';
+import { CollapsedQueue } from '@/misc/collapsed-queue.js';
+import { MiNote } from '@/models/Note.js';
 
 @Injectable()
 export class InboxProcessorService {
 	private logger: Logger;
+	private updateInstanceQueue: CollapsedQueue<MiNote['id'], Date>;
 
 	constructor(
 		private utilityService: UtilityService,
@@ -48,6 +51,7 @@ export class InboxProcessorService {
 		private queueLoggerService: QueueLoggerService,
 	) {
 		this.logger = this.queueLoggerService.logger.createSubLogger('inbox');
+		this.updateInstanceQueue = new CollapsedQueue(60 * 1000 * 5, this.collapseUpdateInstanceJobs, this.performUpdateInstance);
 	}
 
 	@bindThis
@@ -180,10 +184,7 @@ export class InboxProcessorService {
 
 		// Update stats
 		this.federatedInstanceService.fetch(authUser.user.host).then(i => {
-			this.federatedInstanceService.update(i.id, {
-				latestRequestReceivedAt: new Date(),
-				isNotResponding: false,
-			});
+			this.updateInstanceQueue.enqueue(i.id, new Date());
 
 			this.fetchInstanceMetadataService.fetchInstanceMetadata(i);
 
@@ -211,4 +212,17 @@ export class InboxProcessorService {
 		}
 		return 'ok';
 	}
+
+	@bindThis
+	public collapseUpdateInstanceJobs(oldValue: Date, newValue: Date) {
+		return oldValue < newValue ? newValue : oldValue;
+	}
+
+	@bindThis
+	public performUpdateInstance(id: string, value: Date) {
+		this.federatedInstanceService.update(id, {
+			latestRequestReceivedAt: value,
+			isNotResponding: false,
+		});
+	}
 }