Merge pull request #239 from projectdiscovery/introduce_lockable

introduce generic lockable type

generic/lockable.go

@@ -0,0 +1,20 @@
+package generic
+
+import (
+	"sync"
+)
+
+type Lockable[K any] struct {
+	V K
+	sync.RWMutex
+}
+
+func (v *Lockable[K]) Do(f func(val K)) {
+	v.Lock()
+	defer v.Unlock()
+	f(v.V)
+}
+
+func WithLock[K any](val K) *Lockable[K] {
+	return &Lockable[K]{V: val}
+}

generic/lockable_test.go

@@ -0,0 +1,55 @@
+package generic
+
+import (
+	"sync"
+	"testing"
+)
+
+func TestDo(t *testing.T) {
+	val := 10
+	l := WithLock(val)
+	l.Do(func(v int) {
+		if v != val {
+			t.Errorf("Expected %d, got %d", val, v)
+		}
+	})
+}
+
+func TestLockableConcurrency(t *testing.T) {
+	l := WithLock(0)
+
+	var wg sync.WaitGroup
+
+	for i := 0; i < 100; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for j := 0; j < 1000; j++ {
+				l.Do(func(v int) {
+					v++
+					l.V = v
+				})
+			}
+		}()
+	}
+
+	wg.Wait()
+
+	if l.V != 100*1000 {
+		t.Errorf("Expected counter to be %d, but got %d", 100*1000, l.V)
+	}
+}
+
+func TestLockableStringManipulation(t *testing.T) {
+	str := "initial"
+	l := WithLock(str)
+
+	l.Do(func(s string) {
+		s += " - updated"
+		l.V = s
+	})
+
+	if l.V != "initial - updated" {
+		t.Errorf("Expected 'initial - updated', got '%s'", str)
+	}
+}