Refactor concurrency handling and improve sleep precision in concurrency.dart and header.dart

dart/lib/sweepstore.dart

@@ -40,7 +40,7 @@ class Sweepstore {
       keyHash: key.hashCode,
       writeSize: 0, // Placeholder
       onApproved: () {
-        print("Writing key: $key with hash ${key.hashCode} and value: $value");
+        // print("Writing key: $key with hash ${key.hashCode} and value: $value");
       },
       debugLabel: key
     );
@@ -60,16 +60,16 @@ Future<void> main() async {
 
   Sweepstore store = Sweepstore(filePath);
   store.initialise(
-    concurrentWorkers: 20
+    concurrentWorkers: 18
   );
   initialiseMasterListener(file.openSync(mode: FileMode.append));
 
   print(binaryDump(file.readAsBytesSync()));
 
-  int iteration = 1;
+  int iteration = 100;
 
   for (int j = 0; j < iteration; j++) {
-    int concurrencyTest = 256;
+    int concurrencyTest = 128;
     final receivePort = ReceivePort();
     int completedJobs = 0;
 
@@ -101,5 +101,7 @@ Future<void> main() async {
 
     print('\x1B[95mAll jobs completed!\x1B[0m');
     print('\x1B[95mTime taken: ${stopwatch.elapsedMilliseconds}ms (${stopwatch.elapsed.inSeconds}s)\x1B[0m');
+
+    // sleep(Duration(seconds: 2));
   }
 }