From 5a40fb2e159cb4879747bbfd8d9e70675f5f0f10 Mon Sep 17 00:00:00 2001
From: James Garbutt <43081j@users.noreply.github.com>
Date: Thu, 2 Jan 2025 15:05:56 +0000
Subject: [PATCH] perf: skip maxDepth filtering if natively supported

Skips `maxDepth` filtering if _all_ drivers in the current storage
instance natively support it (via the `maxDepth` flag).

Also enables the `maxDepth` flag for `fs` and `fs-lite` drivers.
---
 src/drivers/fs-lite.ts | 3 +++
 src/drivers/fs.ts      | 3 +++
 src/storage.ts         | 9 +++++++--
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/drivers/fs-lite.ts b/src/drivers/fs-lite.ts
index a7ebbb31..2fff2094 100644
--- a/src/drivers/fs-lite.ts
+++ b/src/drivers/fs-lite.ts
@@ -40,6 +40,9 @@ export default defineDriver((opts: FSStorageOptions = {}) => {
   return {
     name: DRIVER_NAME,
     options: opts,
+    flags: {
+      maxDepth: true,
+    },
     hasItem(key) {
       return existsSync(r(key));
     },
diff --git a/src/drivers/fs.ts b/src/drivers/fs.ts
index b2bcc5ed..3e7e1e1b 100644
--- a/src/drivers/fs.ts
+++ b/src/drivers/fs.ts
@@ -59,6 +59,9 @@ export default defineDriver((opts: FSStorageOptions = {}) => {
   return {
     name: DRIVER_NAME,
     options: opts,
+    flags: {
+      maxDepth: true,
+    },
     hasItem(key) {
       return existsSync(r(key));
     },
diff --git a/src/storage.ts b/src/storage.ts
index 7cacb064..eb657847 100644
--- a/src/storage.ts
+++ b/src/storage.ts
@@ -348,7 +348,11 @@ export function createStorage<T extends StorageValue>(
       const mounts = getMounts(base, true);
       let maskedMounts: string[] = [];
       const allKeys = [];
+      let allMountsSupportMaxDepth = true;
       for (const mount of mounts) {
+        if (!mount.driver.flags?.maxDepth) {
+          allMountsSupportMaxDepth = false;
+        }
         const rawKeys = await asyncCall(
           mount.driver.getKeys,
           mount.relativeBase,
@@ -368,10 +372,11 @@ export function createStorage<T extends StorageValue>(
           ...maskedMounts.filter((p) => !p.startsWith(mount.mountpoint)),
         ];
       }
+      const shouldFilterByDepth =
+        opts.maxDepth !== undefined && !allMountsSupportMaxDepth;
       return allKeys.filter(
         (key) =>
-          (opts.maxDepth === undefined ||
-            filterKeyByDepth(key, opts.maxDepth)) &&
+          (!shouldFilterByDepth || filterKeyByDepth(key, opts.maxDepth)) &&
           filterKeyByBase(key, base)
       );
     },