import asyncio import time import traceback import uuid from asgiref.sync import sync_to_async from django.http import HttpResponse from django.views import View from miniq.models import Task from users.models import Identity class QueueProcessor(View): """ A view that takes some items off the queue and processes them. Tries to limit its own runtime so it's within HTTP timeout limits. """ START_TIMEOUT = 30 TOTAL_TIMEOUT = 60 MAX_TASKS = 10 async def get(self, request): start_time = time.monotonic() processor_id = uuid.uuid4().hex handled = 0 self.tasks = [] # For the first time period, launch tasks while (time.monotonic() - start_time) < self.START_TIMEOUT: # Remove completed tasks self.tasks = [t for t in self.tasks if not t.done()] # See if there's a new task if len(self.tasks) < self.MAX_TASKS: # Pop a task off the queue and run it task = await sync_to_async(Task.get_one_available)(processor_id) if task is not None: self.tasks.append(asyncio.create_task(self.run_task(task))) handled += 1 # Prevent busylooping await asyncio.sleep(0.01) # Then wait for tasks to finish while (time.monotonic() - start_time) < self.TOTAL_TIMEOUT: # Remove completed tasks self.tasks = [t for t in self.tasks if not t.done()] if not self.tasks: break # Prevent busylooping await asyncio.sleep(1) return HttpResponse(f"{handled} tasks handled") async def run_task(self, task): try: print(f"Task {task}: Starting") handler = getattr(self, f"handle_{task.type}", None) if handler is None: raise ValueError(f"Cannot handle type {task.type}") await handler(task.subject, task.payload) await task.complete() print(f"Task {task}: Complete") except BaseException as e: print(f"Task {task}: Error {e}") traceback.print_exc() await task.fail(f"{e}\n\n" + traceback.format_exc()) async def handle_identity_fetch(self, subject, payload): # Get the actor URI via webfinger actor_uri, handle = await Identity.fetch_webfinger(subject) # Get or create the identity, then fetch identity = await sync_to_async(Identity.by_actor_uri)(actor_uri, create=True) await identity.fetch_actor()