Add optional S3-based storage

src/storage/LocalStorageAdapter.ts

@@ -0,0 +1,28 @@
+import { IStorageAdapter } from "./index";
+import { promises as fs } from "fs";
+import path from "path";
+
+export class LocalStorageAdapter implements IStorageAdapter {
+    baseDir: string;
+
+    constructor(baseDir: string) {
+        this.baseDir = baseDir;
+    }
+
+    async save(key: string, data: Buffer): Promise<string> {
+        const fullPath = path.join(this.baseDir, key);
+        await fs.mkdir(path.dirname(fullPath), { recursive: true });
+        await fs.writeFile(fullPath, data);
+        return key;
+    }
+
+    async get(key: string): Promise<Buffer> {
+        const fullPath = path.join(this.baseDir, key);
+        return fs.readFile(fullPath);
+    }
+
+    async delete(key: string): Promise<void> {
+        const fullPath = path.join(this.baseDir, key);
+        await fs.unlink(fullPath);
+    }
+}