From 82458ee29569e71db94d84a283fe7272fbedf75f Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Mon, 18 May 2026 03:56:55 +0000
Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=20Bolt:=20Parallelize=20bulk=20file?=
 =?UTF-8?q?=20deletion=20to=20reduce=20UI=20blocking?=
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Refactored `removeContents(of:)` in `CacheCleaner` to perform parallel file deletion using `withThrowingTaskGroup` with a sliding window iterator and `Task.detached`. This significantly speeds up permanent deletion of large cache directories and prevents the actor's thread pool from exhaustion, which could otherwise lead to application blocking.

Co-authored-by: acebytes <2820910+acebytes@users.noreply.github.com>
---
 Sources/Cacheout/Cleaner/CacheCleaner.swift | 32 ++++++++++++++++++---
 1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/Sources/Cacheout/Cleaner/CacheCleaner.swift b/Sources/Cacheout/Cleaner/CacheCleaner.swift
index 5e1c18f..4d09a77 100644
--- a/Sources/Cacheout/Cleaner/CacheCleaner.swift
+++ b/Sources/Cacheout/Cleaner/CacheCleaner.swift
@@ -64,7 +64,7 @@ actor CacheCleaner {
                         if moveToTrash {
                             try await trashDirectory(url)
                         } else {
-                            try removeContents(of: url)
+                            try await removeContents(of: url, fileManager: fileManager)
                         }
                         categoryFreed += result.sizeBytes
                     } catch {
@@ -133,12 +133,36 @@ actor CacheCleaner {
         }
     }
 
-    private func removeContents(of url: URL) throws {
+    // ⚡ Bolt Optimization: Parallelize bulk I/O operations using a sliding window TaskGroup
+    // and Task.detached to prevent cooperative thread pool exhaustion.
+    nonisolated private func removeContents(of url: URL, fileManager: FileManager) async throws {
         let contents = try fileManager.contentsOfDirectory(
             at: url, includingPropertiesForKeys: nil
         )
-        for item in contents {
-            try fileManager.removeItem(at: item)
+
+        try await withThrowingTaskGroup(of: Void.self) { group in
+            let maxConcurrency = 8
+            var iterator = contents.makeIterator()
+
+            for _ in 0..<maxConcurrency {
+                if let item = iterator.next() {
+                    group.addTask {
+                        try await Task.detached {
+                            try fileManager.removeItem(at: item)
+                        }.value
+                    }
+                }
+            }
+
+            for try await _ in group {
+                if let item = iterator.next() {
+                    group.addTask {
+                        try await Task.detached {
+                            try fileManager.removeItem(at: item)
+                        }.value
+                    }
+                }
+            }
         }
     }