Implement cleanup and timestamp

gotcha.go

@@ -157,6 +157,28 @@ func (g *Gotcha) Expired(index interface{}) bool {
 	return it != nil && expired(it)
 }
 
+// Cleanup removes all expired data
+func (g *Gotcha) Cleanup() {
+	g.m.Lock()
+	defer g.m.Unlock()
+	for index, it := range g.d {
+		if expired(it) {
+			delete(g.d, index)
+		}
+	}
+}
+
+// Timestamp returns timestamp of an index
+func (g *Gotcha) Timestamp(index interface{}) *time.Time {
+	g.m.RLock()
+	defer g.m.RUnlock()
+	it := g.d[index]
+	if it == nil {
+		return nil
+	}
+	return &it.ts
+}
+
 // helper funcitons
 func expired(it *item) bool {
 	if it.ttl <= 0 {

gotcha_test.go

@@ -121,3 +121,30 @@ func TestExpired(t *testing.T) {
 		t.Errorf("expected 1 expired")
 	}
 }
+
+func TestCleanup(t *testing.T) {
+	g := New()
+	g.SetTTL(1, 2, time.Millisecond*10)
+	g.SetTTL(2, 3, time.Millisecond*20)
+	time.Sleep(time.Millisecond * 15)
+	g.Cleanup()
+	if g.Exists(1) {
+		t.Errorf("expected 1 not exists")
+	}
+	if !g.Exists(2) {
+		t.Errorf("expected 2 exists")
+	}
+}
+
+func TestTimestamp(t *testing.T) {
+	g := New()
+	g.SetTTL(1, 2, time.Millisecond*10)
+	ts := g.Timestamp(1)
+	if ts == nil {
+		t.Errorf("expected timestamp not nil")
+	}
+	ts = g.Timestamp(2)
+	if ts != nil {
+		t.Errorf("expected timestamp to be nil")
+	}
+}