mqtt: support configurable status update interval

SIgned-off-by:  Eric Callahan <arksine.code@gmail.com>

moonraker/components/mqtt.py

@@ -38,6 +38,7 @@ from typing import (
 if TYPE_CHECKING:
     from ..confighelper import ConfigHelper
     from ..common import JsonRPC, APIDefinition
+    from ..eventloop import FlexTimer
     from .klippy_apis import KlippyAPI
     FlexCallback = Callable[[bytes], Optional[Coroutine]]
     RPCCallback = Callable[..., Coroutine]
@@ -323,6 +324,10 @@ class MQTTClient(APITransport):
         status_cfg: Dict[str, str] = config.getdict(
             "status_objects", {}, allow_empty_fields=True
         )
+        self.status_interval = config.getfloat("status_interval", 0, above=.25)
+        self.status_cache: Dict[str, Dict[str, Any]] = {}
+        self.status_update_timer: Optional[FlexTimer] = None
+        self.last_status_time = 0.
         self.status_objs: Dict[str, Optional[List[str]]] = {}
         for key, val in status_cfg.items():
             if val is not None:
@@ -334,6 +339,13 @@ class MQTTClient(APITransport):
             self.server.register_event_handler(
                 "server:klippy_started", self._handle_klippy_started
             )
+            self.server.register_event_handler(
+                "server:klippy_disconnect", self._handle_klippy_disconnect
+            )
+            if self.status_interval:
+                self.status_update_timer = self.eventloop.register_timer(
+                    self._handle_timed_status_update
+                )
 
         self.timestamp_deque: Deque = deque(maxlen=20)
         self.api_qos = config.getint('api_qos', self.qos)
@@ -371,6 +383,16 @@ class MQTTClient(APITransport):
             await kapi.subscribe_from_transport(
                 self.status_objs, self, default=None,
             )
+            if self.status_update_timer is not None:
+                self.status_update_timer.start(delay=self.status_interval)
+
+    def _handle_klippy_disconnect(self):
+        if self.status_update_timer is not None:
+            self.status_update_timer.stop()
+        if self.status_cache:
+            payload = self.status_cache
+            self.status_cache = {}
+            self._publish_status_update(payload, self.last_status_time)
 
     def _on_message(self,
                     client: str,
@@ -694,18 +716,29 @@ class MQTTClient(APITransport):
             else:
                 self.timestamp_deque.append(ts)
 
-    def send_status(self,
-                    status: Dict[str, Any],
-                    eventtime: float
-                    ) -> None:
+    def send_status(self, status: Dict[str, Any], eventtime: float) -> None:
         if not status or not self.is_connected():
             return
+        if not self.status_interval:
+            self._publish_status_update(status, eventtime)
+        else:
+            for key, val in status.items():
+                self.status_cache.setdefault(key, {}).update(val)
+            self.last_status_time = eventtime
+
+    def _handle_timed_status_update(self, eventtime: float) -> float:
+        if self.status_cache:
+            payload = self.status_cache
+            self.status_cache = {}
+            self._publish_status_update(payload, self.last_status_time)
+        return eventtime + self.status_interval
+
+    def _publish_status_update(self, status: Dict[str, Any], eventtime: float) -> None:
         if self.publish_split_status:
             for objkey in status:
                 objval = status[objkey]
                 for statekey in objval:
-                    payload = {'eventtime': eventtime,
-                               'value': objval[statekey]}
+                    payload = {'eventtime': eventtime, 'value': objval[statekey]}
                     self.publish_topic(
                         f"{self.klipper_state_prefix}/{objkey}/{statekey}",
                         payload, retain=True)
@@ -718,6 +751,8 @@ class MQTTClient(APITransport):
         return self.instance_name
 
     async def close(self) -> None:
+        if self.status_update_timer is not None:
+            self.status_update_timer.stop()
         if self.connect_task is not None:
             self.connect_task.cancel()
             self.connect_task = None