1 files changed, 160 insertions, 0 deletions
diff --git a/src/util/cache/EntityCache.ts b/src/util/cache/EntityCache.ts
new file mode 100644
index 00000000..9135fef3
--- /dev/null
+++ b/src/util/cache/EntityCache.ts
@@ -0,0 +1,160 @@
+/*
+	Fosscord: A FOSS re-implementation and extension of the Discord.com backend.
+	Copyright (C) 2023 Fosscord and Fosscord Contributors
+	
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU Affero General Public License as published
+	by the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+	
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU Affero General Public License for more details.
+	
+	You should have received a copy of the GNU Affero General Public License
+	along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+/* eslint-disable */
+import {
+	DataSource,
+	FindOneOptions,
+	EntityNotFoundError,
+	FindOptionsWhere,
+} from "typeorm";
+import { QueryDeepPartialEntity } from "typeorm/query-builder/QueryPartialEntity";
+import { BaseClassWithId } from "../entities/BaseClass";
+import { Config, getDatabase } from "../util";
+import { CacheManager } from "./Cache";
+
+function getObjectKeysAsArray(obj?: Record<string, any>) {
+	if (!obj) return [];
+	if (Array.isArray(obj)) return obj;
+	return Object.keys(obj);
+}
+
+export type ThisType<T> = {
+	new (): T;
+} & typeof BaseEntityCache;
+
+interface BaseEntityCache {
+	constructor: typeof BaseEntityCache;
+}
+
+// @ts-ignore
+class BaseEntityCache extends BaseClassWithId {
+	static cache: CacheManager;
+	static cacheEnabled: boolean;
+
+	public get metadata() {
+		return getDatabase()?.getMetadata(this.constructor)!;
+	}
+
+	static useDataSource(dataSource: DataSource | null) {
+		super.useDataSource(dataSource);
+		this.cacheEnabled = Config.get().cache.enabled ?? true;
+		if (Config.get().cache.redis) return; // TODO: Redis cache
+		if (!this.cacheEnabled) return;
+		this.cache = new CacheManager();
+	}
+
+	static async findOne<T extends BaseEntityCache>(
+		this: ThisType<T>,
+		options: FindOneOptions<T>,
+	) {
+		// @ts-ignore
+		if (!this.cacheEnabled) return super.findOne(options);
+		let select = getObjectKeysAsArray(options.select);
+
+		if (!select.length) {
+			// get all columns that are marked as select
+			getDatabase()
+				?.getMetadata(this)
+				.columns.forEach((x) => {
+					if (!x.isSelect) return;
+					select.push(x.propertyName);
+				});
+		}
+		if (options.relations) {
+			select.push(...getObjectKeysAsArray(options.relations));
+		}
+
+		const cacheResult = this.cache.find(options.where as never, select);
+		if (cacheResult) {
+			const hasAllProps = select.every((key) => {
+				if (key.includes(".")) return true; // @ts-ignore
+				return cacheResult[key] !== undefined;
+			});
+			// console.log(`[Cache] get ${cacheResult.id} from ${cacheResult.constructor.name}`,);
+			if (hasAllProps) return cacheResult;
+		}
+
+		// @ts-ignore
+		const result = await super.findOne<T>(options);
+		if (!result) return null;
+
+		this.cache.insert(result as any);
+
+		return result;
+	}
+
+	static async findOneOrFail<T extends BaseEntityCache>(
+		this: ThisType<T>,
+		options: FindOneOptions<T>,
+	) {
+		const result = await this.findOne<T>(options);
+		if (!result) throw new EntityNotFoundError(this, options);
+		return result;
+	}
+
+	save() {
+		if (this.constructor.cacheEnabled) this.constructor.cache.insert(this);
+		return super.save();
+	}
+
+	remove() {
+		if (this.constructor.cacheEnabled)
+			this.constructor.cache.delete(this.id);
+		return super.remove();
+	}
+
+	static async update<T extends BaseEntityCache>(
+		this: ThisType<T>,
+		criteria: FindOptionsWhere<T>,
+		partialEntity: QueryDeepPartialEntity<T>,
+	) {
+		// @ts-ignore
+		const result = super.update<T>(criteria, partialEntity);
+		if (!this.cacheEnabled) return result;
+
+		const entities = this.cache.filter(criteria as never);
+		for (const entity of entities) {
+			// @ts-ignore
+			partialEntity.id = entity.id;
+			this.cache.insert(partialEntity as never);
+		}
+
+		return result;
+	}
+
+	static async delete<T extends BaseEntityCache>(
+		this: ThisType<T>,
+		criteria: FindOptionsWhere<T>,
+	) {
+		// @ts-ignore
+		const result = super.delete<T>(criteria);
+		if (!this.cacheEnabled) return result;
+
+		const entities = this.cache.filter(criteria as never);
+		for (const entity of entities) {
+			this.cache.delete(entity.id);
+		}
+
+		return result;
+	}
+}
+
+// needed, because typescript can't infer the type of the static methods with generics
+const EntityCache = BaseEntityCache as unknown as typeof BaseClassWithId;
+
+export { EntityCache };