Added indexdb wrapper & cache support for it

src/database.ts

@@ -0,0 +1,60 @@
+export class Collection<K extends IDBValidKey, T> {
+	private database: Promise<IDBDatabase>;
+
+	constructor(public readonly db: string, public readonly collection: string, public readonly version?: number, private setup?: (db: IDBDatabase, event: IDBVersionChangeEvent) => void) {
+		this.database = new Promise((resolve, reject) => {
+			const req = indexedDB.open(this.db, this.version);
+			req.onerror = () => reject(req.error);
+			req.onsuccess = () => resolve(req.result);
+			req.onupgradeneeded = (event) => {
+				const db = req.result;
+				if(!db.objectStoreNames.contains(collection)) db.createObjectStore(collection, {keyPath: undefined});
+				if (this.setup) this.setup(db, event as IDBVersionChangeEvent);
+			};
+		});
+	}
+
+	async tx<T>(collection: string, fn: ((store: IDBObjectStore) => IDBRequest), readonly?: boolean): Promise<T> {
+		const db = await this.database;
+		const tx = db.transaction(collection, readonly ? 'readonly' : 'readwrite');
+		const store = tx.objectStore(collection);
+		return new Promise((resolve, reject) => {
+			const request = fn(store);
+			request.onsuccess = () => resolve(request.result);
+			request.onerror = () => reject(request.error);
+		});
+	}
+
+	add(value: T, key?: K): Promise<void> {
+		return this.tx(this.collection, store => store.add(value, key));
+	}
+
+	count(): Promise<number> {
+		return this.tx(this.collection, store => store.count(), true);
+	}
+
+	put(key: K, value: T): Promise<void> {
+		debugger;
+		return this.tx(this.collection, store => store.put(value, key));
+	}
+
+	getAll(): Promise<T[]> {
+		return this.tx(this.collection, store => store.getAll(), true);
+	}
+
+	getAllKeys(): Promise<K[]> {
+		return this.tx(this.collection, store => store.getAllKeys(), true);
+	}
+
+	get(key: K): Promise<T> {
+		return this.tx(this.collection, store => store.get(key), true);
+	}
+
+	delete(key: K): Promise<void> {
+		return this.tx(this.collection, store => store.delete(key));
+	}
+
+	clear(): Promise<void> {
+		return this.tx(this.collection, store => store.clear());
+	}
+}