Refactor: detect deleted cached files subset on a timer (#1157)

src/types/files/fileCache.ts

@@ -1,7 +1,6 @@
-import { Semaphore } from 'async-mutex';
-
 import Constants from '../../constants.js';
 import FsPoly from '../../polyfill/fsPoly.js';
+import Timer from '../../timer.js';
 import Cache from '../cache.js';
 import Archive from './archives/archive.js';
 import ArchiveEntry, { ArchiveEntryProps } from './archives/archiveEntry.js';
@@ -46,26 +45,21 @@ export default class FileCache {
 
     // Delete keys for deleted files
     const disks = FsPoly.disksSync();
-    const semaphore = new Semaphore(Constants.MAX_FS_THREADS);
-    await Promise.all(
-      [...this.cache.keys()]
+    Timer.setTimeout(async () => {
+      await Promise.all([...this.cache.keys()]
+        .map((cacheKey) => cacheKey.split('|')[1])
+        // Don't delete the key if it's for a disk that isn't mounted right now
+        .filter((cacheKeyFilePath) => disks.some((disk) => cacheKeyFilePath.startsWith(disk)))
         // Only process a reasonably sized subset of the keys
         .sort(() => Math.random() - 0.5)
-        .slice(0, Constants.MAX_FS_THREADS * 100)
-        .map(async (cacheKey) => {
-          const cacheKeyFilePath = cacheKey.split('|')[1];
-          if (!disks.some((disk) => cacheKeyFilePath.startsWith(disk))) {
-            // Don't delete the key if it's for a disk that isn't mounted right now
-            return;
+        .slice(0, Constants.MAX_FS_THREADS)
+        .map(async (cacheKeyFilePath) => {
+          if (!await FsPoly.exists(cacheKeyFilePath)) {
+            // If the file no longer exists, then delete its key from the cache
+            await this.cache.delete(cacheKeyFilePath);
           }
-          await semaphore.runExclusive(async () => {
-            if (!await FsPoly.exists(cacheKeyFilePath)) {
-              // If the file no longer exists, then delete its key from the cache
-              await this.cache.delete(cacheKeyFilePath);
-            }
-          });
-        }),
-    );
+        }));
+    }, 10_000);
   }
 
   public static async save(): Promise<void> {