feature: Add an empty implementation of the CDN manager

Signed-off-by: Starnop <starnop@163.com>

supernode/daemon/mgr/cdn_mgr.go

@@ -19,6 +19,29 @@ type CDNMgr interface {
 	// GetStatus get the status of the file.
 	GetStatus(ctx context.Context, taskID string) (cdnStatus string, err error)
 
-	// Delete delete the file from disk with specified taskID.
+	// Delete the file from disk with specified taskID.
 	Delete(ctx context.Context, taskID string) error
 }
+
+// CDNManager is an implementation of the interface of CDNMgr.
+type CDNManager struct{}
+
+// NewCDNManager returns a new CDNManager.
+func NewCDNManager() (*CDNManager, error) {
+	return &CDNManager{}, nil
+}
+
+// TriggerCDN will trigger CDN to download the file from sourceUrl.
+func (cm *CDNManager) TriggerCDN(ctx context.Context, taskInfo *types.TaskInfo) error {
+	return nil
+}
+
+// GetStatus get the status of the file.
+func (cm *CDNManager) GetStatus(ctx context.Context, taskID string) (cdnStatus string, err error) {
+	return "", nil
+}
+
+// Delete the file from disk with specified taskID.
+func (cm *CDNManager) Delete(ctx context.Context, taskID string) error {
+	return nil
+}