改进心跳检测中的订阅状态检查，通过读取服务器节点属性来验证订阅是否真正有效

src/connection.rs

@@ -281,7 +281,7 @@ impl ConnectionManager {
                 // 检查session是否有效
                 let session = manager.get_session(source_id).await;
 
-                let session_valid = if let Some(session) = session {
+                let (session_valid, subscription_valid) = if let Some(session) = session {
                             // 尝试读取当前时间来验证连接
                             let node_id = NodeId::new(0, 2258); // ServerCurrentTime节点
                             let read_request = ReadValueId {
@@ -291,23 +291,58 @@ impl ConnectionManager {
                                 data_encoding: Default::default(),
                             };
                             
-                            match session.read(&[read_request], TimestampsToReturn::Neither, 0f64).await {
+                            let session_valid = match session.read(&[read_request], TimestampsToReturn::Neither, 0f64).await {
                                 Ok(_) => true,
                                 Err(_) => false,
-                            }
+                            };
+
+                            // 检查订阅状态
+                            let subscription_valid = {
+                                let status = manager.status.read().await;
+                                if let Some(conn_status) = status.get(&source_id) {
+                                    if let Some(_subscription_id) = conn_status.subscription_id {
+                                        // 尝试读取订阅的属性来验证订阅是否真正有效
+                                        let node_id = NodeId::new(0, 2253); // ServerServiceLevel节点
+                                        let read_request = ReadValueId {
+                                            node_id,
+                                            attribute_id: AttributeId::Value as u32,
+                                            index_range: NumericRange::None,
+                                            data_encoding: Default::default(),
+                                        };
+
+                                        match session.read(&[read_request], TimestampsToReturn::Neither, 0f64).await {
+                                            Ok(_) => true,
+                                            Err(_) => false,
+                                        }
+                                    } else {
+                                        false
+                                    }
+                                } else {
+                                    false
+                                }
+                            };
+
+                            (session_valid, subscription_valid)
                 } else {
-                    false
+                    (false, false)
                 };
 
-                if !session_valid {
+                if !session_valid || !subscription_valid {
                     // 检查是否已经在重连中
                     let mut reconnecting = manager.reconnecting.write().await;
                     if !reconnecting.contains(&source_id) {
                         reconnecting.insert(source_id);
                         drop(reconnecting);
                         
+                        let reason = if !session_valid {
+                            "invalid session"
+                        } else {
+                            "invalid subscription"
+                        };
+
                         tracing::warn!(
-                            "Heartbeat detected invalid session for source {}, triggering reconnection",
+                            "Heartbeat detected {} for source {}, triggering reconnection",
+                            reason,
                             source_id
                         );
                     
@@ -1074,21 +1109,6 @@ impl ConnectionManager {
                         0,
                         true,
                         opcua::client::DataChangeCallback::new(move |dv, item| {
-                            // 检查是否有 BadNoSubscription 错误
-                            if let Some(status) = &dv.status {
-                                if *status == opcua::types::StatusCode::BadNoSubscription {
-                                    tracing::warn!(
-                                        "Detected BadNoSubscription in data change callback for source {}, triggering reconnection",
-                                        current_source_id
-                                    );
-                                    // 触发重连
-                                    if let Some(tx) = manager.reconnect_tx.as_ref() {
-                                        let _ = tx.send(current_source_id);
-                                    }
-                                    return;
-                                }
-                            }
-
                             let client_handle = item.client_handle();
                             let val = dv.value;
                             let timex = Some(Utc::now());