perf(backend): cache timeline of a channel to redis

packages/backend/src/core/IdService.ts

@@ -2,7 +2,7 @@ import { Inject, Injectable } from '@nestjs/common';
 import { ulid } from 'ulid';
 import { DI } from '@/di-symbols.js';
 import type { Config } from '@/config.js';
-import { genAid } from '@/misc/id/aid.js';
+import { genAid, parseAid } from '@/misc/id/aid.js';
 import { genMeid } from '@/misc/id/meid.js';
 import { genMeidg } from '@/misc/id/meidg.js';
 import { genObjectId } from '@/misc/id/object-id.js';
@@ -32,4 +32,17 @@ export class IdService {
 			default: throw new Error('unrecognized id generation method');
 		}
 	}
+
+	@bindThis
+	public parse(id: string): { date: Date; } {
+		switch (this.method) {
+			case 'aid': return parseAid(id);
+			// TODO
+			//case 'meid':
+			//case 'meidg':
+			//case 'ulid':
+			//case 'objectid':
+			default: throw new Error('unrecognized id generation method');
+		}
+	}
 }

packages/backend/src/core/NoteCreateService.ts

@@ -1,6 +1,7 @@
 import { setImmediate } from 'node:timers/promises';
 import * as mfm from 'mfm-js';
 import { In, DataSource } from 'typeorm';
+import Redis from 'ioredis';
 import { Inject, Injectable, OnApplicationShutdown } from '@nestjs/common';
 import { extractMentions } from '@/misc/extract-mentions.js';
 import { extractCustomEmojisFromMfm } from '@/misc/extract-custom-emojis-from-mfm.js';
@@ -150,6 +151,9 @@ export class NoteCreateService implements OnApplicationShutdown {
 		@Inject(DI.db)
 		private db: DataSource,
 
+		@Inject(DI.redis)
+		private redisClient: Redis.Redis,
+
 		@Inject(DI.usersRepository)
 		private usersRepository: UsersRepository,
 
@@ -321,6 +325,10 @@ export class NoteCreateService implements OnApplicationShutdown {
 
 		const note = await this.insertNote(user, data, tags, emojis, mentionedUsers);
 
+		if (data.channel) {
+			this.redisClient.xadd(`channelTimeline:${data.channel.id}`, 'MAXLEN', '~', '1000', `${this.idService.parse(note.id).date.getTime()}-*`, 'note', note.id);
+		}
+
 		setImmediate('post created', { signal: this.#shutdownController.signal }).then(
 			() => this.postNoteCreated(note, user, data, silent, tags!, mentionedUsers!),
 			() => { /* aborted, ignore this */ },

packages/backend/src/misc/id/aid.ts

@@ -23,3 +23,8 @@ export function genAid(date: Date): string {
 	counter++;
 	return getTime(t) + getNoise();
 }
+
+export function parseAid(id: string): { date: Date; } {
+	const time = parseInt(id.slice(0, 8), 36) + TIME2000;
+	return { date: new Date(time) };
+}

packages/backend/src/server/api/endpoints/channels/timeline.ts

@@ -1,10 +1,12 @@
 import { Inject, Injectable } from '@nestjs/common';
+import Redis from 'ioredis';
 import { Endpoint } from '@/server/api/endpoint-base.js';
 import type { ChannelsRepository, NotesRepository } from '@/models/index.js';
 import { QueryService } from '@/core/QueryService.js';
 import { NoteEntityService } from '@/core/entities/NoteEntityService.js';
 import ActiveUsersChart from '@/core/chart/charts/active-users.js';
 import { DI } from '@/di-symbols.js';
+import { IdService } from '@/core/IdService.js';
 import { ApiError } from '../../error.js';
 
 export const meta = {
@@ -48,12 +50,16 @@ export const paramDef = {
 @Injectable()
 export default class extends Endpoint<typeof meta, typeof paramDef> {
 	constructor(
+		@Inject(DI.redis)
+		private redisClient: Redis.Redis,
+
 		@Inject(DI.notesRepository)
 		private notesRepository: NotesRepository,
 
 		@Inject(DI.channelsRepository)
 		private channelsRepository: ChannelsRepository,
 
+		private idService: IdService,
 		private noteEntityService: NoteEntityService,
 		private queryService: QueryService,
 		private activeUsersChart: ActiveUsersChart,
@@ -67,9 +73,25 @@ export default class extends Endpoint<typeof meta, typeof paramDef> {
 				throw new ApiError(meta.errors.noSuchChannel);
 			}
 
+			const noteIdsRes = await this.redisClient.xrevrange(
+				`channelTimeline:${channel.id}`,
+				ps.untilId ? this.idService.parse(ps.untilId).date.getTime() : '+',
+				'-',
+				'COUNT', ps.limit + 1); // untilIdに指定したものも含まれるため+1
+
+			if (noteIdsRes.length === 0) {
+				return [];
+			}
+
+			const noteIds = noteIdsRes.map(x => x[1][1]).filter(x => x !== ps.untilId);
+
+			if (noteIds.length === 0) {
+				return [];
+			}
+
 			//#region Construct query
-			const query = this.queryService.makePaginationQuery(this.notesRepository.createQueryBuilder('note'), ps.sinceId, ps.untilId, ps.sinceDate, ps.untilDate)
-				.andWhere('note.channelId = :channelId', { channelId: channel.id })
+			const query = this.notesRepository.createQueryBuilder('note')
+				.where('note.id IN (:...noteIds)', { noteIds: noteIds })
 				.innerJoinAndSelect('note.user', 'user')
 				.leftJoinAndSelect('user.avatar', 'avatar')
 				.leftJoinAndSelect('user.banner', 'banner')
@@ -90,7 +112,8 @@ export default class extends Endpoint<typeof meta, typeof paramDef> {
 			}
 			//#endregion
 
-			const timeline = await query.take(ps.limit).getMany();
+			const timeline = await query.getMany();
+			timeline.sort((a, b) => a.id > b.id ? -1 : 1);
 
 			if (me) this.activeUsersChart.read(me);