feat: Introduce Meilisearch (#10755)

* wip

* wip

* Update SearchService.ts

* Update SearchService.ts

* wip

* wip

* Update SearchService.ts

* Update CHANGELOG.md

* wip

* Update SearchService.ts

* Update docker-compose.yml.example

1 files changed, 166 insertions, 0 deletions

diff --git a/packages/backend/src/core/SearchService.ts b/packages/backend/src/core/SearchService.ts
new file mode 100644
index 0000000000..67332581f7
--- /dev/null
+++ b/packages/backend/src/core/SearchService.ts
@@ -0,0 +1,166 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { In } from 'typeorm';
+import { DI } from '@/di-symbols.js';
+import type { Config } from '@/config.js';
+import { bindThis } from '@/decorators.js';
+import { Note } from '@/models/entities/Note.js';
+import { User } from '@/models/index.js';
+import type { NotesRepository } from '@/models/index.js';
+import { sqlLikeEscape } from '@/misc/sql-like-escape.js';
+import { QueryService } from '@/core/QueryService.js';
+import { IdService } from '@/core/IdService.js';
+import type { Index, MeiliSearch } from 'meilisearch';
+
+type K = string;
+type V = string | number | boolean;
+type Q =
+	{ op: '=', k: K, v: V } |
+	{ op: '!=', k: K, v: V } |
+	{ op: '>', k: K, v: number } |
+	{ op: '<', k: K, v: number } |
+	{ op: '>=', k: K, v: number } |
+	{ op: '<=', k: K, v: number } |
+	{ op: 'and', qs: Q[] } |
+	{ op: 'or', qs: Q[] } |
+	{ op: 'not', q: Q };
+
+function compileValue(value: V): string {
+	if (typeof value === 'string') {
+		return `'${value}'`; // TODO: escape
+	} else if (typeof value === 'number') {
+		return value.toString();
+	} else if (typeof value === 'boolean') {
+		return value.toString();
+	}
+	throw new Error('unrecognized value');
+}
+
+function compileQuery(q: Q): string {
+	switch (q.op) {
+		case '=': return `(${q.k} = ${compileValue(q.v)})`;
+		case '!=': return `(${q.k} != ${compileValue(q.v)})`;
+		case '>': return `(${q.k} > ${compileValue(q.v)})`;
+		case '<': return `(${q.k} < ${compileValue(q.v)})`;
+		case '>=': return `(${q.k} >= ${compileValue(q.v)})`;
+		case '<=': return `(${q.k} <= ${compileValue(q.v)})`;
+		case 'and': return q.qs.length === 0 ? '' : `(${ q.qs.map(_q => compileQuery(_q)).join(' AND ') })`;
+		case 'or': return q.qs.length === 0 ? '' : `(${ q.qs.map(_q => compileQuery(_q)).join(' OR ') })`;
+		case 'not': return `(NOT ${compileQuery(q.q)})`;
+		default: throw new Error('unrecognized query operator');
+	}
+}
+
+@Injectable()
+export class SearchService {
+	private meilisearchNoteIndex: Index | null = null;
+
+	constructor(
+		@Inject(DI.config)
+		private config: Config,
+
+		@Inject(DI.meilisearch)
+		private meilisearch: MeiliSearch | null,
+
+		@Inject(DI.notesRepository)
+		private notesRepository: NotesRepository,
+
+		private queryService: QueryService,
+		private idService: IdService,
+	) {
+		if (meilisearch) {
+			this.meilisearchNoteIndex = meilisearch.index('notes');
+			this.meilisearchNoteIndex.updateSettings({
+				searchableAttributes: [
+					'text',
+					'cw',
+				],
+				sortableAttributes: [
+					'createdAt',
+				],
+				filterableAttributes: [
+					'createdAt',
+					'userId',
+					'userHost',
+					'channelId',
+				],
+				typoTolerance: {
+					enabled: false,
+				},
+				pagination: {
+					maxTotalHits: 10000,
+				},
+			});
+		}
+	}
+
+	@bindThis
+	public async indexNote(note: Note): Promise<void> {
+		if (this.meilisearch) {
+			this.meilisearchNoteIndex!.addDocuments([{
+				id: note.id,
+				createdAt: note.createdAt.getTime(),
+				userId: note.userId,
+				userHost: note.userHost,
+				channelId: note.channelId,
+				cw: note.cw,
+				text: note.text,
+			}], {
+				primaryKey: 'id',
+			});
+		}
+	}
+
+	@bindThis
+	public async searchNote(q: string, me: User | null, opts: {
+		userId?: Note['userId'] | null;
+		channelId?: Note['channelId'] | null;
+	}, pagination: {
+		untilId?: Note['id'];
+		sinceId?: Note['id'];
+		limit?: number;
+	}): Promise<Note[]> {
+		if (this.meilisearch) {
+			const filter: Q = {
+				op: 'and',
+				qs: [],
+			};
+			if (pagination.untilId) filter.qs.push({ op: '<', k: 'createdAt', v: this.idService.parse(pagination.untilId).date.getTime() });
+			if (pagination.sinceId) filter.qs.push({ op: '>', k: 'createdAt', v: this.idService.parse(pagination.sinceId).date.getTime() });
+			if (opts.userId) filter.qs.push({ op: '=', k: 'userId', v: opts.userId });
+			if (opts.channelId) filter.qs.push({ op: '=', k: 'channelId', v: opts.channelId });
+			const res = await this.meilisearchNoteIndex!.search(q, {
+				sort: ['createdAt:desc'],
+				matchingStrategy: 'all',
+				attributesToRetrieve: ['id', 'createdAt'],
+				filter: compileQuery(filter),
+				limit: pagination.limit,
+			});
+			if (res.hits.length === 0) return [];
+			return await this.notesRepository.findBy({
+				id: In(res.hits.map(x => x.id)),
+			});
+		} else {
+			const query = this.queryService.makePaginationQuery(this.notesRepository.createQueryBuilder('note'), pagination.sinceId, pagination.untilId);
+
+			if (opts.userId) {
+				query.andWhere('note.userId = :userId', { userId: opts.userId });
+			} else if (opts.channelId) {
+				query.andWhere('note.channelId = :channelId', { channelId: opts.channelId });
+			}
+
+			query
+				.andWhere('note.text ILIKE :q', { q: `%${ sqlLikeEscape(q) }%` })
+				.innerJoinAndSelect('note.user', 'user')
+				.leftJoinAndSelect('note.reply', 'reply')
+				.leftJoinAndSelect('note.renote', 'renote')
+				.leftJoinAndSelect('reply.user', 'replyUser')
+				.leftJoinAndSelect('renote.user', 'renoteUser');
+
+			this.queryService.generateVisibilityQuery(query, me);
+			if (me) this.queryService.generateMutedUserQuery(query, me);
+			if (me) this.queryService.generateBlockedUserQuery(query, me);
+
+			return await query.take(pagination.limit).getMany();
+		}
+	}
+}