From 305250d0738b1fc7332ee9556b8d9e6aed5a8237 Mon Sep 17 00:00:00 2001
From: Hazelnoot <acomputerdog@gmail.com>
Date: Sat, 24 May 2025 18:29:10 -0400
Subject: [PATCH] persist changes to meta host lists to instance table

---
 packages/backend/src/core/MetaService.ts | 55 +++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 2 deletions(-)

diff --git a/packages/backend/src/core/MetaService.ts b/packages/backend/src/core/MetaService.ts
index 40e7439f5f..16be22ac19 100644
--- a/packages/backend/src/core/MetaService.ts
+++ b/packages/backend/src/core/MetaService.ts
@@ -4,7 +4,7 @@
  */
 
 import { Inject, Injectable } from '@nestjs/common';
-import { DataSource } from 'typeorm';
+import { DataSource, EntityManager } from 'typeorm';
 import * as Redis from 'ioredis';
 import { DI } from '@/di-symbols.js';
 import { MiMeta } from '@/models/Meta.js';
@@ -12,6 +12,8 @@ import { GlobalEventService } from '@/core/GlobalEventService.js';
 import { bindThis } from '@/decorators.js';
 import type { GlobalEvents } from '@/core/GlobalEventService.js';
 import { FeaturedService } from '@/core/FeaturedService.js';
+import { MiInstance } from '@/models/Instance.js';
+import { diffArrays } from '@/misc/diff-arrays.js';
 import type { OnApplicationShutdown } from '@nestjs/common';
 
 @Injectable()
@@ -103,7 +105,7 @@ export class MetaService implements OnApplicationShutdown {
 		let before: MiMeta | undefined;
 
 		const updated = await this.db.transaction(async transactionalEntityManager => {
-			const metas = await transactionalEntityManager.find(MiMeta, {
+			const metas: (MiMeta | undefined)[] = await transactionalEntityManager.find(MiMeta, {
 				order: {
 					id: 'DESC',
 				},
@@ -126,6 +128,10 @@ export class MetaService implements OnApplicationShutdown {
 				},
 			});
 
+			// Propagate changes to blockedHosts, silencedHosts, mediaSilencedHosts, federationInstances, and bubbleInstances to the relevant instance rows
+			// Do this inside the transaction to avoid potential race condition (when an instance gets registered while we're updating).
+			await this.persistBlocks(transactionalEntityManager, before ?? {}, afters[0]);
+
 			return afters[0];
 		});
 
@@ -159,4 +165,49 @@ export class MetaService implements OnApplicationShutdown {
 	public onApplicationShutdown(signal?: string | undefined): void {
 		this.dispose();
 	}
+
+	private async persistBlocks(tem: EntityManager, before: Partial<MiMeta>, after: Partial<MiMeta>): Promise<void> {
+		await this.persistBlock(tem, before.blockedHosts, after.blockedHosts, 'isBlocked');
+		await this.persistBlock(tem, before.silencedHosts, after.silencedHosts, 'isSilenced');
+		await this.persistBlock(tem, before.mediaSilencedHosts, after.mediaSilencedHosts, 'isMediaSilenced');
+		await this.persistBlock(tem, before.federationHosts, after.federationHosts, 'isAllowListed');
+		await this.persistBlock(tem, before.bubbleInstances, after.bubbleInstances, 'isBubbled');
+	}
+
+	private async persistBlock(tem: EntityManager, before: string[] | undefined, after: string[] | undefined, field: keyof MiInstance): Promise<void> {
+		const { added, removed } = diffArrays(before, after);
+
+		if (removed.length > 0) {
+			await this.updateInstancesByHost(tem, field, false, removed);
+		}
+
+		if (added.length > 0) {
+			await this.updateInstancesByHost(tem, field, true, added);
+		}
+	}
+
+	private async updateInstancesByHost(tem: EntityManager, field: keyof MiInstance, value: boolean, hosts: string[]): Promise<void> {
+		// Use non-array queries when possible, as they are indexed and can be much faster.
+		if (hosts.length === 1) {
+			const pattern = genHostPattern(hosts[0]);
+			await tem
+				.createQueryBuilder(MiInstance, 'instance')
+				.update()
+				.set({ [field]: value })
+				.where('(lower(reverse("host")) || \'.\') LIKE :pattern', { pattern })
+				.execute();
+		} else if (hosts.length > 1) {
+			const patterns = hosts.map(host => genHostPattern(host));
+			await tem
+				.createQueryBuilder(MiInstance, 'instance')
+				.update()
+				.set({ [field]: value })
+				.where('(lower(reverse("host")) || \'.\') LIKE ANY (:patterns)', {patterns})
+				.execute();
+		}
+	}
+}
+
+function genHostPattern(host: string): string {
+	return host.toLowerCase().split('').reverse().join('') + '.%';
 }