fix: 首次握手失败停止重连并修正 Java 限速在途计数

sdk/python/src/nixmsg/transport.py

@@ -8,16 +8,23 @@ from dataclasses import dataclass, field
 from typing import Any, Callable, Optional, Protocol
 from urllib.parse import urlparse
 
-from paho.mqtt.client import CallbackAPIVersion, Client as PahoClient, MQTT_ERR_SUCCESS, MQTTv5
-from paho.mqtt.enums import MQTTErrorCode
-from paho.mqtt.reasoncodes import ReasonCode
-
 DownHandler = Callable[[bytes], None]
 ConnHandler = Callable[[], None]
 DiscHandler = Callable[[Optional[str], bool], None]
 # reason_code_str, stop_reconnect
 
 
+def _require_paho():
+    """真实 MQTT 路径才加载 paho；假传输单测不依赖。"""
+    try:
+        from paho.mqtt.client import CallbackAPIVersion, Client as PahoClient, MQTT_ERR_SUCCESS, MQTTv5
+        from paho.mqtt.enums import MQTTErrorCode
+        from paho.mqtt.reasoncodes import ReasonCode
+    except ImportError as e:
+        raise ImportError("需要 paho-mqtt>=2.0（真实 MQTT 连接）") from e
+    return CallbackAPIVersion, PahoClient, MQTT_ERR_SUCCESS, MQTTv5, MQTTErrorCode, ReasonCode
+
+
 @dataclass
 class ConnectParams:
     url: str
@@ -180,7 +187,7 @@ class PahoTransport:
     """paho-mqtt 2.x CallbackAPIVersion.VERSION2。"""
 
     def __init__(self) -> None:
-        self._client: Optional[PahoClient] = None
+        self._client: Any = None
         self._on_connected: Optional[ConnHandler] = None
         self._on_disconnected: Optional[DiscHandler] = None
         self._on_down: Optional[DownHandler] = None
@@ -200,6 +207,7 @@ class PahoTransport:
         self._on_down = on_down
 
     def connect(self, params: ConnectParams) -> None:
+        CallbackAPIVersion, PahoClient, _, MQTTv5, _, _ = _require_paho()
         self.disconnect()
         url = params.url
         u = urlparse(url if "://" in url else "ws://" + url)
@@ -261,6 +269,7 @@ class PahoTransport:
         # 等待连接结果由回调驱动；超时由 Client 层处理
 
     def subscribe(self, topic: str) -> None:
+        _, _, MQTT_ERR_SUCCESS, _, _, _ = _require_paho()
         self._down_topic = topic
         if not self._client:
             return
@@ -273,6 +282,7 @@ class PahoTransport:
             raise RuntimeError("subscribe timeout")
 
     def publish(self, topic: str, payload: bytes) -> None:
+        _, _, MQTT_ERR_SUCCESS, _, _, _ = _require_paho()
         if not self._client:
             raise RuntimeError("not connected")
         info = self._client.publish(topic, payload, qos=1)
@@ -338,9 +348,14 @@ def _reason_to_int(reason_code) -> Optional[int]:
         return None
     if isinstance(reason_code, int):
         return reason_code
-    if isinstance(reason_code, ReasonCode):
+    try:
+        _, _, _, _, MQTTErrorCode, ReasonCode = _require_paho()
+    except ImportError:
+        MQTTErrorCode = ()  # type: ignore[assignment,misc]
+        ReasonCode = ()  # type: ignore[assignment,misc]
+    if ReasonCode and isinstance(reason_code, ReasonCode):
         return int(reason_code.value)
-    if isinstance(reason_code, MQTTErrorCode):
+    if MQTTErrorCode and isinstance(reason_code, MQTTErrorCode):
         return int(reason_code)
     # paho 偶发其它包装
     val = getattr(reason_code, "value", None)