4 files changed, 339 insertions, 0 deletions
diff --git a/src/util/cache/Cache.ts b/src/util/cache/Cache.ts
new file mode 100644
index 00000000..fb66c2e3
--- /dev/null
+++ b/src/util/cache/Cache.ts
@@ -0,0 +1,85 @@
+/*
+	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 @typescript-eslint/ban-ts-comment */
+/* eslint-disable @typescript-eslint/no-explicit-any */
+
+import { EntityMetadata, FindOptionsWhere } from "typeorm";
+import { LocalCache } from "./LocalCache";
+
+declare module "typeorm" {
+	interface BaseEntity {
+		metadata?: EntityMetadata;
+		cache: CacheManager;
+	}
+}
+
+export type BaseEntityWithId = { id: string; [name: string]: any };
+export type Criteria =
+	| string
+	| string[]
+	| number
+	| number[]
+	| FindOptionsWhere<never>;
+
+export interface Cache {
+	get(id: string): BaseEntityWithId | undefined;
+	set(id: string, entity: BaseEntityWithId): this;
+	find(options: Record<string, never>): BaseEntityWithId | undefined;
+	filter(options: Record<string, never>): BaseEntityWithId[];
+	delete(id: string): boolean;
+}
+
+export class CacheManager {
+	// last access time to automatically remove old entities from cache after 5 minutes of inactivity (to prevent memory leaks)
+	cache: Cache;
+
+	constructor() {
+		this.cache = new LocalCache();
+		// TODO: Config.get().cache.redis;
+	}
+
+	delete(id: string) {
+		return this.cache.delete(id);
+	}
+
+	insert(entity: BaseEntityWithId) {
+		if (!entity.id) return;
+
+		return this.cache.set(entity.id, entity);
+	}
+
+	find(options?: Record<string, never>, select?: string[] | undefined) {
+		if (!options) return null;
+		const entity = this.cache.find(options);
+		if (!entity) return null;
+		if (!select) return entity;
+
+		const result = {};
+		for (const prop of select) {
+			// @ts-ignore
+			result[prop] = entity[prop];
+		}
+
+		// @ts-ignore
+		return entity.constructor.create(result);
+	}
+
+	filter(options: Record<string, never>) {
+		return this.cache.filter(options);
+	}
+}
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 };
diff --git a/src/util/cache/LocalCache.ts b/src/util/cache/LocalCache.ts
new file mode 100644
index 00000000..547899ac
--- /dev/null
+++ b/src/util/cache/LocalCache.ts
@@ -0,0 +1,91 @@
+/*
+	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 @typescript-eslint/ban-ts-comment */
+import { BaseEntityWithId, Cache } from "./Cache";
+
+export const cacheTimeout = 1000 * 60 * 5;
+
+export class LocalCache extends Map<string, BaseEntityWithId> implements Cache {
+	last_access = new Map<string, number>();
+
+	constructor() {
+		super();
+
+		setInterval(() => {
+			const now = Date.now();
+			for (const [key, value] of this.last_access) {
+				if (now - value > cacheTimeout) {
+					this.delete(key);
+					this.last_access.delete(key);
+				}
+			}
+		}, cacheTimeout);
+	}
+
+	set(key: string, value: BaseEntityWithId): this {
+		this.last_access.set(key, Date.now());
+		if (this.has(key)) this.update(key, value);
+		return super.set(key, value as never);
+	}
+
+	get(key: string) {
+		const value = super.get(key);
+		if (value) this.last_access.set(key, Date.now());
+		return value;
+	}
+
+	update(id: string, entity: BaseEntityWithId) {
+		const oldEntity = this.get(id);
+		if (!oldEntity) return;
+		for (const key in entity) {
+			// @ts-ignore
+			if (entity[key] === undefined) continue; // @ts-ignore
+			oldEntity[key] = entity[key];
+		}
+	}
+
+	find(options: Record<string, never>): BaseEntityWithId | undefined {
+		if (options.id && Object.keys(options).length === 1) {
+			return this.get(options.id);
+		}
+		for (const entity of this.values()) {
+			if (objectFulfillsQuery(entity, options)) return entity;
+		}
+	}
+
+	filter(options: Record<string, never>): BaseEntityWithId[] {
+		const result = [];
+		for (const entity of this.values()) {
+			if (objectFulfillsQuery(entity, options)) {
+				result.push(entity);
+			}
+		}
+		return result;
+	}
+}
+
+function objectFulfillsQuery(
+	entity: BaseEntityWithId,
+	options: Record<string, never>,
+) {
+	for (const key in options) {
+		// @ts-ignore
+		if (entity[key] !== options[key]) return false;
+	}
+	return true;
+}
diff --git a/src/util/cache/index.ts b/src/util/cache/index.ts
new file mode 100644
index 00000000..43f0aa96
--- /dev/null
+++ b/src/util/cache/index.ts
@@ -0,0 +1,3 @@
+export * from "./EntityCache";
+export * from "./Cache";
+export * from "./LocalCache";