From 03dfb2ecb818dd7b41bd82b9ef434c396258600f Mon Sep 17 00:00:00 2001
From: pooya parsa <pooya@pi0.io>
Date: Mon, 6 Feb 2023 15:27:57 +0100
Subject: [PATCH] feat: `lru-cache` driver (#146)

---
 README.md                | 15 ++++++++++++++
 package.json             |  1 +
 pnpm-lock.yaml           |  7 +++++++
 src/drivers/lru-cache.ts | 42 ++++++++++++++++++++++++++++++++++++++++
 src/index.ts             |  1 +
 5 files changed, 66 insertions(+)
 create mode 100644 src/drivers/lru-cache.ts

diff --git a/README.md b/README.md
index 1af1884b..4c87537c 100644
--- a/README.md
+++ b/README.md
@@ -360,6 +360,21 @@ const storage = createStorage({
 });
 ```
 
+### `lru-cache` (universal)
+
+Keeps cached data in memory using [LRU Cache](https://www.npmjs.com/package/lru-cache).
+
+See [`lru-cache`](https://www.npmjs.com/package/lru-cache) for supported options. By default `{ maxSize: 500 }` is used.
+
+```js
+import { createStorage } from "unstorage";
+import lruCacheDriver from "unstorage/drivers/lru-cache";
+
+const storage = createStorage({
+  driver: lruCacheDriver(),
+});
+```
+
 ### `overlay` (universal)
 
 This is a special driver that creates a multi-layer overlay driver.
diff --git a/package.json b/package.json
index b643b348..633794d2 100644
--- a/package.json
+++ b/package.json
@@ -46,6 +46,7 @@
     "h3": "^1.1.0",
     "ioredis": "^5.3.0",
     "listhen": "^1.0.2",
+    "lru-cache": "^7.14.1",
     "mkdir": "^0.0.2",
     "mri": "^1.2.0",
     "node-fetch-native": "^1.0.1",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 5ed73e68..50e0c32a 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -22,6 +22,7 @@ specifiers:
   jiti: ^1.16.2
   jsdom: ^21.1.0
   listhen: ^1.0.2
+  lru-cache: ^7.14.1
   mkdir: ^0.0.2
   monaco-editor: ^0.34.1
   mri: ^1.2.0
@@ -45,6 +46,7 @@ dependencies:
   h3: 1.1.0
   ioredis: 5.3.0
   listhen: 1.0.2
+  lru-cache: 7.14.1
   mkdir: 0.0.2
   mri: 1.2.0
   node-fetch-native: 1.0.1
@@ -3302,6 +3304,11 @@ packages:
       yallist: 4.0.0
     dev: true
 
+  /lru-cache/7.14.1:
+    resolution: {integrity: sha512-ysxwsnTKdAx96aTRdhDOCQfDgbHnt8SK0KY8SEjO0wHinhWOFTESbjVCMPbU1uGXg/ch4lifqx0wfjOawU2+WA==}
+    engines: {node: '>=12'}
+    dev: false
+
   /magic-string/0.25.9:
     resolution: {integrity: sha512-RmF0AsMzgt25qzqqLc1+MbHmhdx0ojF2Fvs4XnOqz2ZOBXzzkEwc/dJQZCYHAn7v1jbVOjAZfK8msRn4BxO4VQ==}
     dependencies:
diff --git a/src/drivers/lru-cache.ts b/src/drivers/lru-cache.ts
new file mode 100644
index 00000000..37752671
--- /dev/null
+++ b/src/drivers/lru-cache.ts
@@ -0,0 +1,42 @@
+import { defineDriver } from "./utils";
+import LRU, { SharedOptions as _LRUOptions } from "lru-cache";
+
+type LRUOptions = _LRUOptions<string, any>;
+export interface LRUDriverOptions extends LRUOptions {}
+
+export default defineDriver((opts: LRUDriverOptions) => {
+  const cache = new LRU({
+    ...opts,
+    maxSize: 500,
+  });
+
+  return {
+    hasItem(key) {
+      return cache.has(key);
+    },
+    getItem(key) {
+      return cache.get(key) || null;
+    },
+    getItemRaw(key) {
+      return cache.get(key) || null;
+    },
+    setItem(key, value) {
+      cache.set(key, value);
+    },
+    setItemRaw(key, value) {
+      cache.set(key, value);
+    },
+    removeItem(key) {
+      cache.delete(key);
+    },
+    getKeys() {
+      return Array.from(cache.keys());
+    },
+    clear() {
+      cache.clear();
+    },
+    dispose() {
+      cache.clear();
+    },
+  };
+});
diff --git a/src/index.ts b/src/index.ts
index dbb12ce4..0c533fcd 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -12,6 +12,7 @@ export const builtinDrivers = {
   github: "unstorage/drivers/github",
   http: "unstorage/drivers/http",
   localStorage: "unstorage/drivers/localstorage",
+  lruCache: "unstorage/drivers/lru-cache",
   localstorage: "unstorage/drivers/localstorage",
   memory: "unstorage/drivers/memory",
   overlay: "unstorage/drivers/overlay",