From 9960eeaa4a4435b4b547e856c3df1e4093bd499e Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Fri, 3 Apr 2026 05:19:10 +0000
Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=20Bolt:=20Optimize=20ProcessMemorySca?=
 =?UTF-8?q?nner=20chunking=20with=20sliding=20window?=
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- Replaced static array chunking with a continuous sliding window using `iterator.next()` inside `withTaskGroup`.
- Prevents tail latency waiting for the slowest PID scan in a static chunk.
- Reduces intermediate array allocations.

Co-authored-by: acebytes <2820910+acebytes@users.noreply.github.com>
---
 .../Memory/ProcessMemoryScanner.swift         | 40 +++++++++++--------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/Sources/Cacheout/Memory/ProcessMemoryScanner.swift b/Sources/Cacheout/Memory/ProcessMemoryScanner.swift
index 3f8e728..5e3556e 100644
--- a/Sources/Cacheout/Memory/ProcessMemoryScanner.swift
+++ b/Sources/Cacheout/Memory/ProcessMemoryScanner.swift
@@ -97,29 +97,37 @@ actor ProcessMemoryScanner {
     ///
     /// Returns the collected entries and the count of EPERM failures.
     private func scanPIDs(_ pids: [pid_t]) async -> (entries: [ProcessEntryDTO], epermCount: Int) {
-        // Chunk PIDs to cap concurrency at maxConcurrency.
-        let chunks = stride(from: 0, to: pids.count, by: maxConcurrency).map {
-            Array(pids[$0..<min($0 + maxConcurrency, pids.count)])
-        }
-
         var allEntries: [ProcessEntryDTO] = []
         var totalEperm = 0
 
-        for chunk in chunks {
-            await withTaskGroup(of: ScanPIDResult.self) { group in
-                for pid in chunk {
+        // Use a sliding window approach with an iterator instead of static chunking
+        // to maintain maximum concurrent execution limits continuously and improve throughput.
+        await withTaskGroup(of: ScanPIDResult.self) { group in
+            var iterator = pids.makeIterator()
+
+            // Initial batch
+            for _ in 0..<maxConcurrency {
+                if let pid = iterator.next() {
                     group.addTask { [self] in
                         self.scanSinglePID(pid)
                     }
                 }
-                for await result in group {
-                    switch result {
-                    case .success(let entry):
-                        allEntries.append(entry)
-                    case .eperm:
-                        totalEperm += 1
-                    case .otherError:
-                        break
+            }
+
+            // Add new tasks as existing ones complete
+            for await result in group {
+                switch result {
+                case .success(let entry):
+                    allEntries.append(entry)
+                case .eperm:
+                    totalEperm += 1
+                case .otherError:
+                    break
+                }
+
+                if let pid = iterator.next() {
+                    group.addTask { [self] in
+                        self.scanSinglePID(pid)
                     }
                 }
             }