您好,我有以下脚本,它监听 Google pubsub 消息,在回调中我将消息传递给另一个带有循环参数的脚本。
在第二个脚本中,我有一个具有依赖 future 功能的任务。但是 future 函数永远不会被调用。
import os, time
import base64, json
import asyncio
from google.cloud import pubsub_v1
from app.libs.pubsub.pubsub_connect import PubsubConnect
from app.config import config
from evergage.scripts.evga_process import initEvga
from app.utils import log
LOG = log.get_logger()
PROJECT_NAME = config.get('pubsub', 'project_name')
SUBSCRIPTION = config.get('pubsub', 'insights_subscription')
class PubsubConsumer(PubsubConnect):
_subscriber = None
def __init__(self, loop):
self._subscriber = self.getClientService()
#loop.create_task( self.getMessages(loop) )
self.getMessages(loop)
def getMessages(self, loop):
def consumeMessageTask(message):
#loop.create_task( self.callback(message, loop) )
loop.call_soon( self.callback(message, loop) )
subscription_path = self._subscriber.subscription_path( PROJECT_NAME, SUBSCRIPTION )
flow_control = pubsub_v1.types.FlowControl(max_messages=10)
self._subscriber.subscribe(subscription_path, callback=consumeMessageTask, flow_control=flow_control)
#loop.run_forever()
def callback(self, message, loop):
pubSubMsg = message.data.decode("utf-8")
pubSubMsg = json.loads( base64.urlsafe_b64decode( pubSubMsg) )
if pubSubMsg['verb']['display'] == 'evga_upsert':
loop.create_task( initEvga(pubSubMsg, loop) )
message.ack()
asyncLoop = asyncio.get_event_loop()
test = PubsubConsumer(asyncLoop)
asyncLoop.run_forever()
asyncLoop.close()
第二个文件evga_process.py
import os, time
import base64, json
import asyncio
import functools
from app.config import config
from app.utils import log
LOG = log.get_logger()
MKTO_BATCH = {
'count': 0,
'total': 5,
'data': []
}
async def getMarketoData(cookies):
#await asyncio.sleep(0.1)
tmpData = []
for cookie in cookies:
tmpData.append("test-" + cook)
return tmpData
def initSalesforce(future, param1):
result = future.result()
LOG.info( param1 )
LOG.info( str(result) )
pass
def initEvga(pubSubMsg, loop):
pubSubID = pubSubMsg['id']
upsertInfo = pubSubMsg['object']['definition']['description']
MKTO_BATCH['data'].append(pubSubID)
MKTO_BATCH['count'] += 1
if MKTO_BATCH['count'] == MKTO_BATCH['total']:
mktoTask = loop.create_task( getMarketoData(MKTO_BATCH['data']) )
mktoTask.add_done_callback( functools.partial( initSalesforce, "myparam1") )
MKTO_BATCH['count'] = 0
MKTO_BATCH['data'] = []
我什至尝试使用简单的代码,但它不起作用。它只工作,如果我这样打电话
loop = asyncio.get_event_loop()
task = loop.create_task( test_task(loop) )
initEvga(loop)
task.add_done_callback(got_result)
我在这里遗漏了什么吗?
单个文件中的更新脚本</p>
async def heartbeat1():
while True:
await asyncio.sleep(1)
print("heartbeat 1")
async def heartbeat2():
while True:
await asyncio.sleep(1)
print("heartbeat 2")
class PubsubConsumer(PubsubConnect):
_subscriber = None
def __init__(self, loop):
self._subscriber = self.getClientService()
def getMessages(self, loop):
def consumeMessageTask(message):
#loop.create_task( self.callback(message, loop) )
#loop.call_soon( self.callback(message, loop) )
PubsubConsumer.callback(message, loop)
subscription_path = self._subscriber.subscription_path( PROJECT_NAME, SUBSCRIPTION )
#subClient.subscribe(subscription_path, callback=PubsubConnect.callback)
# Limit the subscriber to only have ten outstanding messages at a time.
flow_control = pubsub_v1.types.FlowControl(max_messages=10)
self._subscriber.subscribe(subscription_path, callback=consumeMessageTask, flow_control=flow_control)
#loop.run_forever()
@staticmethod
def callback(message, loop):
time.sleep(1)
pubSubMsg = message.data.decode("utf-8")
pubSubMsg = json.loads( base64.urlsafe_b64decode( pubSubMsg) )
loop.create_task( heartbeat2() )
message.ack()
loop = asyncio.get_event_loop()
loop.create_task( heartbeat1() )
psClient = PubsubConsumer(loop)
psClient.getMessages(loop)
loop.run_forever()
loop.close()
heartbeat1() 和 heartbeat2() 都正常调用。但是,如果我删除 heartbeat1() 调用,则 heartbeat2() 也不会触发。
这是什么原因?如果我让 heartbeat1() 一直运行,它会产生任何问题吗?
谢谢, 巴拉
最佳答案
这一行绝对是不正确的:
mktoTask.add_done_callback( functools.partial( initSalesforce, "myparam1")
您不能将异步函数发送到 add_done_callback
,它需要一个常规函数。调用时,异步/协程函数返回一个协程对象,而不执行其中的任何代码。要实际执行代码,协程对象必须提交给事件循环。在您的情况下,它将被删除而不执行函数内部的代码。 (这很像调用生成器,但永远不会将返回的迭代器传递给将从中提取值的对象。)
你需要的是这样的:
async def initEvga(pubSubMsg):
...
if MKTO_BATCH['count'] == MKTO_BATCH['total']:
await getMarketoData(MKTO_BATCH['data'])
await initSalesforce("myparam1")
...
现在 initEvga
是一个协程,使用以下方法从 callback
启动它:
loop.create_task(initEvga(pubSubMsg))
...或者,如果回调是从不同的线程调用的:
asyncio.run_coroutine_threadsafe(initEvga(pubSubMsg), loop)
(您不需要将 loop
传递给 asyncio 函数,它们总是可以通过调用 asyncio.get_event_loop()
来获取正在运行的事件循环。)
最后,loop.call_soon(self.callback(message, loop))
没有意义,因为call_soon
接受一个函数来调用,上面的代码是使用 self.callback()
的结果 调用它,它会立即被调用。您需要:
self.callback(message, loop)
或类似的东西:
loop.call_soon(self.callback, message, loop)
# or loop.call_soon_threadsafe if called from a different thread
由于在这两种情况下 callback
都必须简短且非阻塞,推迟它似乎没有任何好处,所以我会选择第一个变体。
关于python - 在另一个文件中使用 Asyncio 循环引用,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/49533612/