Add New GetItemsAndFlush method

Author: oGabrielArruda

cache.go

@@ -1052,6 +1052,35 @@ func (c *cache) Items() map[string]Item {
 	return m
 }
 
+// Copies all unexpired items from the cache into a new map,
+// then deletes all items from the cache and returns the original map. This
+// approach ensures that no items are lost due to race conditions that could
+// occur if the operations of copying and deleting were performed separately.
+// For example, a race condition might occur if an item is added to the cache
+// between the calls to Items() and Flush(), resulting in data loss. By
+// combining these operations within a single lock, we maintain data integrity
+// during the cache cleanup process.
+func (c *cache) GetItemsAndFlush() map[string]Item {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	m := make(map[string]Item, len(c.items))
+	now := time.Now().UnixNano()
+	for k, v := range c.items {
+		// "Inlining" of Expired
+		if v.Expiration > 0 {
+			if now > v.Expiration {
+				continue
+			}
+		}
+		m[k] = v
+	}
+
+	c.items = map[string]Item{}
+
+	return m
+}
+
 // Returns the number of items in the cache. This may include items that have
 // expired, but have not yet been cleaned up.
 func (c *cache) ItemCount() int {

cache_test.go

@@ -1769,3 +1769,68 @@ func TestGetWithExpiration(t *testing.T) {
 		t.Error("expiration for e is in the past")
 	}
 }
+
+func TestGetItemsAndFlush(t *testing.T) {
+	tc := New(DefaultExpiration, 0)
+	tc.Set("foo", "bar", DefaultExpiration)
+	tc.Set("baz", "yes", DefaultExpiration)
+	m := tc.GetItemsAndFlush()
+
+	// Assert get items was executed
+	x, found := m["foo"]
+	if !found {
+		t.Error("foo was not found in the map, but it should be returned")
+	}
+
+	if x.Expiration != int64(DefaultExpiration) {
+		t.Errorf("foo was found, but its expiration is %v, which is different than the setted one", x.Expiration)
+	}
+
+	v, ok := x.Object.(string)
+	if !ok {
+		t.Error("foo was found, but its value can't be parsed to string")
+	}
+
+	if v != "bar" {
+		t.Errorf("foo was found, but its actual value is %s, different than the original one", v)
+	}
+
+	x, found = m["baz"]
+	if !found {
+		t.Error("baz was not found in the map, but it should be returned")
+	}
+
+	if x.Expiration != int64(DefaultExpiration) {
+		t.Errorf("baz was found, but its expiration is %v, which is different than the setted one", x.Expiration)
+	}
+
+	v, ok = x.Object.(string)
+	if !ok {
+		t.Error("baz was found, but its value can't be parsed to string")
+	}
+
+	if v != "yes" {
+		t.Errorf("baz was found, but its actual value is %s, different than the original one", v)
+	}
+
+	x, found = m["baz"]
+	if !found {
+		t.Error("baz was not found in the map, but it should be returned")
+	}
+
+	// Assert flush was executed
+	y, found := tc.Get("foo")
+	if found {
+		t.Error("foo was found, but it should have been deleted")
+	}
+	if y != nil {
+		t.Error("x is not nil:", x)
+	}
+	y, found = tc.Get("baz")
+	if found {
+		t.Error("baz was found, but it should have been deleted")
+	}
+	if y != nil {
+		t.Error("x is not nil:", x)
+	}
+}