feat: Implement taskrocessing trigger event

ex_app/lib/main.py

@@ -1,13 +1,14 @@
 # SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
 # SPDX-License-Identifier: AGPL-3.0-or-later
+import concurrent.futures
 import os
 import traceback
 from contextlib import asynccontextmanager
 from json import JSONDecodeError
 from threading import Event
 import asyncio
 
-import httpx
+from niquests import RequestException
 import json
 from fastapi import FastAPI
 from nc_py_api import NextcloudApp, NextcloudException
@@ -39,6 +40,9 @@
 fast_app = FastAPI(lifespan=http_mcp_app.lifespan)
 
 app_enabled = Event()
+TRIGGER = Event()
+IDLE_POLLING_INTERVAL = 5
+IDLE_POLLING_INTERVAL_WITH_TRIGGER = 5 * 60
 
 LOCALE_DIR = os.path.join(os.path.dirname(os.path.dirname(__file__)), "locale")
 current_translator = ContextVar("current_translator")
@@ -52,9 +56,14 @@ async def lifespan(app: FastAPI):
     async with exapp_lifespan(app):
         async with http_mcp_app.lifespan(app):
             yield
+
 @asynccontextmanager
 async def exapp_lifespan(app: FastAPI):
-    set_handlers(app, enabled_handler)
+    set_handlers(
+        app,
+        enabled_handler,
+        trigger_handler=trigger_handler,
+    )
     start_bg_task()
     nc = NextcloudApp()
     if nc.enabled_state:
@@ -135,29 +144,23 @@ async def background_thread_task():
         try:
             response = nc.providers.task_processing.next_task([provider.id], [provider.task_type])
             if not response or not 'task' in response:
-                await asyncio.sleep(2)
+                await wait_for_task()
                 continue
-        except (NextcloudException, httpx.RequestError, JSONDecodeError) as e:
+        except (NextcloudException, RequestException, JSONDecodeError) as e:
             tb_str = ''.join(traceback.format_exception(e))
             log(nc, LogLvl.WARNING, "Error fetching the next task " + tb_str)
-            await asyncio.sleep(5)
+            await wait_for_task(5)
             continue
-        except (
-                httpx.RemoteProtocolError,
-                httpx.ReadError,
-                httpx.LocalProtocolError,
-                httpx.PoolTimeout,
-        ) as e:
+        except RequestException as e:
             log(nc, LogLvl.DEBUG, "Ignored error during task polling")
-            await asyncio.sleep(2)
+            await wait_for_task(2)
             continue
 
         task = response["task"]
         log(nc, LogLvl.INFO, 'New Task incoming')
         log(nc, LogLvl.DEBUG, str(task))
         log(nc, LogLvl.INFO, str({'input': task['input']['input'], 'confirmation': task['input']['confirmation'], 'conversation_token': '<skipped>'}))
         asyncio.create_task(handle_task(task, nc))
-        await asyncio.sleep(5)
 
 
 async def handle_task(task, nc: NextcloudApp):
@@ -171,7 +174,7 @@ async def handle_task(task, nc: NextcloudApp):
         log(nc, LogLvl.ERROR, "Error: " + tb_str)
         try:
             nc.providers.task_processing.report_result(task["id"], error_message=str(e))
-        except (NextcloudException, httpx.RequestError) as net_err:
+        except (NextcloudException, RequestException) as net_err:
             tb_str = ''.join(traceback.format_exception(net_err))
             log(nc, LogLvl.WARNING, "Network error in reporting the error: " + tb_str)
         return
@@ -180,7 +183,7 @@ async def handle_task(task, nc: NextcloudApp):
             task["id"],
             output,
         )
-    except (NextcloudException, httpx.RequestError, JSONDecodeError) as e:
+    except (NextcloudException, RequestException, JSONDecodeError) as e:
         tb_str = ''.join(traceback.format_exception(e))
         log(nc, LogLvl.ERROR, "Network error trying to report the task result: " + tb_str)
 
@@ -190,6 +193,29 @@ def start_bg_task():
     loop = asyncio.get_event_loop()
     loop.create_task(background_thread_task())
 
+# Trigger event is available starting with nextcloud v33
+def trigger_handler(providerId: str):
+    global TRIGGER
+    TRIGGER.set()
+
+# Waits for interval seconds or IDLE_POLLING_INTERVAL seconds
+# but can return earlier when TRIGGER event is received from nextcloud
+# if the trigger event is received, IDLE_POLLING_INTERVAL is set to IDLE_POLLING_INTERVAL_WITH_TRIGGER
+async def wait_for_task(interval = None):
+    global TRIGGER
+    global IDLE_POLLING_INTERVAL
+    global IDLE_POLLING_INTERVAL_WITH_TRIGGER
+    if interval is None:
+        interval = IDLE_POLLING_INTERVAL
+    # Call TRIGGER.wait() in a separate thread
+    loop = asyncio.get_running_loop()
+    with concurrent.futures.ThreadPoolExecutor() as pool:
+        was_event = await loop.run_in_executor(pool, TRIGGER.wait, interval)
+    if was_event:
+        IDLE_POLLING_INTERVAL = IDLE_POLLING_INTERVAL_WITH_TRIGGER
+    TRIGGER.clear()
+
+
 APP.mount("/mcp", http_mcp_app)
 
 if __name__ == "__main__":