Added support for delayInMillis in between connection attempts

1 files changed, 12 insertions, 7 deletions

diff --git a/src/main/java/com/it_jaros/networkScanner/Scanner.java b/src/main/java/com/it_jaros/networkScanner/Scanner.java
index 4f1c809..51d5373 100644
--- a/src/main/java/com/it_jaros/networkScanner/Scanner.java
+++ b/src/main/java/com/it_jaros/networkScanner/Scanner.java
@@ -10,30 +10,35 @@ import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.locks.LockSupport;
 
 public class Scanner {
                 
     private Counter counter = new Counter();
-    private final int socketLimitDefault = 1024;
     
     public Scanner() {}
 
     public List<Integer> scanPorts(ScanTarget
      target) {
-        return scanPorts(target.address(), target.openSocketLimit());
-    }
-    
-    public List<Integer> scanPorts(String address) {
-        return scanPorts(address, socketLimitDefault);
+        return scanPorts(target.address(), target.openSocketLimit(), target.delayInMillis());
     }
 
-    public List<Integer> scanPorts(String address, int socketLimit) {
+    public List<Integer> scanPorts(String address, int socketLimit, int delayInMillis) {
         Queue<Integer> openPorts = new ConcurrentLinkedQueue<>();
         Semaphore socketCap = new Semaphore(socketLimit);
+        long delayInNanos = TimeUnit.MILLISECONDS.toNanos(Math.max(0, delayInMillis));
+        AtomicLong nextStartNanos = new AtomicLong(System.nanoTime());
         try (ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor()) {
             for (int port = 1; port < 65536; port++) {
                 final int currentPort = port;
                 executor.submit(() -> {
+                    if (delayInNanos > 0) {
+                        long mySlot = nextStartNanos.getAndAdd(delayInNanos);
+                        long wait = mySlot - System.nanoTime();
+                        if (wait > 0) LockSupport.parkNanos(wait);
+                    }
                     socketCap.acquireUninterruptibly();
                     counter.inc();
                     try (Socket socket = new Socket()) {