implement AP fetch logs

1 files changed, 189 insertions, 0 deletions

diff --git a/packages/backend/src/core/ApLogService.ts b/packages/backend/src/core/ApLogService.ts
new file mode 100644
index 0000000000..362eba24be
--- /dev/null
+++ b/packages/backend/src/core/ApLogService.ts
@@ -0,0 +1,189 @@
+/*
+ * SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { createHash } from 'crypto';
+import { Inject, Injectable } from '@nestjs/common';
+import { LessThan } from 'typeorm';
+import { DI } from '@/di-symbols.js';
+import { SkApFetchLog, SkApInboxLog, SkApContext } from '@/models/_.js';
+import type { ApContextsRepository, ApFetchLogsRepository, ApInboxLogsRepository } from '@/models/_.js';
+import type { Config } from '@/config.js';
+import { JsonValue } from '@/misc/json-value.js';
+import { UtilityService } from '@/core/UtilityService.js';
+import { IdService } from '@/core/IdService.js';
+import { IActivity, IObject } from './activitypub/type.js';
+
+@Injectable()
+export class ApLogService {
+	constructor(
+		@Inject(DI.config)
+		private readonly config: Config,
+
+		@Inject(DI.apContextsRepository)
+		private apContextsRepository: ApContextsRepository,
+
+		@Inject(DI.apInboxLogsRepository)
+		private readonly apInboxLogsRepository: ApInboxLogsRepository,
+
+		@Inject(DI.apFetchLogsRepository)
+		private readonly apFetchLogsRepository: ApFetchLogsRepository,
+
+		private readonly utilityService: UtilityService,
+		private readonly idService: IdService,
+	) {}
+
+	/**
+	 * Creates an inbox log from an activity, and saves it if pre-save is enabled.
+	 */
+	public async createInboxLog(data: Partial<SkApInboxLog> & {
+		activity: IActivity,
+		keyId: string,
+	}): Promise<SkApInboxLog> {
+		const { object: activity, context, contextHash } = extractObjectContext(data.activity);
+		const host = this.utilityService.extractDbHost(data.keyId);
+
+		const log = new SkApInboxLog({
+			id: this.idService.gen(),
+			at: new Date(),
+			verified: false,
+			accepted: false,
+			host,
+			...data,
+			activity,
+			context,
+			contextHash,
+		});
+
+		if (this.config.activityLogging.preSave) {
+			await this.saveInboxLog(log);
+		}
+
+		return log;
+	}
+
+	/**
+	 * Saves or finalizes an inbox log.
+	 */
+	public async saveInboxLog(log: SkApInboxLog): Promise<SkApInboxLog> {
+		if (log.context) {
+			await this.saveContext(log.context);
+		}
+
+		// Will be UPDATE with preSave, and INSERT without.
+		await this.apInboxLogsRepository.upsert(log, ['id']);
+		return log;
+	}
+
+	/**
+	 * Creates a fetch log from an activity, and saves it if pre-save is enabled.
+	 */
+	public async createFetchLog(data: Partial<SkApFetchLog> & {
+		requestUri: string
+		host: string,
+	}): Promise<SkApFetchLog> {
+		const log = new SkApFetchLog({
+			id: this.idService.gen(),
+			at: new Date(),
+			accepted: false,
+			...data,
+		});
+
+		if (this.config.activityLogging.preSave) {
+			await this.saveFetchLog(log);
+		}
+
+		return log;
+	}
+
+	/**
+	 * Saves or finalizes a fetch log.
+	 */
+	public async saveFetchLog(log: SkApFetchLog): Promise<SkApFetchLog> {
+		if (log.context) {
+			await this.saveContext(log.context);
+		}
+
+		// Will be UPDATE with preSave, and INSERT without.
+		await this.apFetchLogsRepository.upsert(log, ['id']);
+		return log;
+	}
+
+	private async saveContext(context: SkApContext): Promise<void> {
+		// https://stackoverflow.com/a/47064558
+		await this.apContextsRepository
+			.createQueryBuilder('activity_context')
+			.insert()
+			.into(SkApContext)
+			.values(context)
+			.orIgnore('md5')
+			.execute();
+	}
+
+	/**
+	 * Deletes all expired AP logs and garbage-collects the AP context cache.
+	 * Returns the total number of deleted rows.
+	 */
+	public async deleteExpiredLogs(): Promise<number> {
+		// This is the date in UTC of the oldest log to KEEP
+		const oldestAllowed = new Date(Date.now() - this.config.activityLogging.maxAge);
+
+		// Delete all logs older than the threshold.
+		const inboxDeleted = await this.deleteExpiredInboxLogs(oldestAllowed);
+		const fetchDeleted = await this.deleteExpiredFetchLogs(oldestAllowed);
+
+		return inboxDeleted + fetchDeleted;
+	}
+
+	private async deleteExpiredInboxLogs(oldestAllowed: Date): Promise<number> {
+		const { affected } = await this.apInboxLogsRepository.delete({
+			at: LessThan(oldestAllowed),
+		});
+
+		return affected ?? 0;
+	}
+
+	private async deleteExpiredFetchLogs(oldestAllowed: Date): Promise<number> {
+		const { affected } = await this.apFetchLogsRepository.delete({
+			at: LessThan(oldestAllowed),
+		});
+
+		return affected ?? 0;
+	}
+}
+
+export function extractObjectContext<T extends IObject>(input: T) {
+	const object = Object.assign({}, input, { '@context': undefined }) as Omit<T, '@context'>;
+	const { context, contextHash } = parseContext(input['@context']);
+
+	return { object, context, contextHash };
+}
+
+export function parseContext(input: JsonValue | undefined): { contextHash: string | null, context: SkApContext | null } {
+	// Empty contexts are excluded for easier querying
+	if (input == null) {
+		return {
+			contextHash: null,
+			context: null,
+		};
+	}
+
+	const contextHash = createHash('md5').update(JSON.stringify(input)).digest('base64');
+	const context = new SkApContext({
+		md5: contextHash,
+		json: input,
+	});
+	return { contextHash, context };
+}
+
+export function calculateDurationSince(startTime: bigint): number {
+	// Calculate the processing time with correct rounding and decimals.
+	// 1. Truncate nanoseconds to microseconds
+	// 2. Scale to 1/10 millisecond ticks.
+	// 3. Round to nearest tick.
+	// 4. Sale to milliseconds
+	// Example: 123,456,789 ns -> 123,456 us -> 12,345.6 ticks -> 12,346 ticks -> 123.46 ms
+	const endTime = process.hrtime.bigint();
+	return Math.round(Number((endTime - startTime) / 1000n) / 10) / 100;
+}