fix: add rwlock for file to ensure thread-safe

file/file.go

@@ -61,18 +61,21 @@ func (f *file) read(key string) (*fileContent, error) {
 		return content, nil
 	}
 
-	if content.Duration <= time.Now().Unix() {
-		_ = f.Delete(key)
-		return nil, errors.New("cache expired")
-	}
-
 	return content, nil
 }
 
 // Contains checks if the cached key exists into the File storage
 func (f *file) Contains(key string) bool {
-	_, err := f.read(key)
-	return err == nil
+	content, err := f.read(key)
+	if err != nil {
+		return false
+	}
+
+	if f.isExpired(content) {
+		_ = f.Delete(key)
+		return false
+	}
+	return true
 }
 
 // Delete the cached key from File storage
@@ -95,9 +98,18 @@ func (f *file) Fetch(key string) (string, error) {
 		return "", err
 	}
 
+	if f.isExpired(content) {
+		_ = f.Delete(key)
+		return "", errors.New("cache expired")
+	}
+
 	return content.Data, nil
 }
 
+func (f *file) isExpired(content *fileContent) bool {
+	return content.Duration > 0 && content.Duration <= time.Now().Unix()
+}
+
 // FetchMulti retrieve multiple cached values from keys of the File storage
 func (f *file) FetchMulti(keys []string) map[string]string {
 	result := make(map[string]string)

file/file_test.go

@@ -41,7 +41,7 @@ func TestFile(t *testing.T) {
 
 	_ = c.Save("bar", testValue, 0)
 
-	if values := c.FetchMulti([]string{testKey, "bar"}); len(values) == 0 {
+	if values := c.FetchMulti([]string{testKey, "bar"}); len(values) != 2 {
 		t.Errorf("fetch multi failed: expected %d, got %d", 2, len(values))
 	}