关于python:RxPy:如何从外部回调创建可观察到的热点并订阅多个异步进程?

RxPy: How to create hot observable from external callback and subscribe multiple asynchronous processes?

我有一个外部服务(ExternalDummyService),在其中注册了回调。我想从该回调中创建一个可观察对象,并订阅多个异步进程。

pyfiddle中的完整代码:https://pyfiddle.io/fiddle/da1e1d53-2e34-4742-a0b9-07838f2c13df
*请注意,在pyfiddle版本中,"睡眠"被替换为" for range(10000)中的i:foo = i",因为睡眠无法正常工作。

主要代码是这样的:

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thread = ExternalDummyService()
external_obs = thread.subject.publish()

external_obs.subscribe(slow_process)
external_obs.subscribe(fast_process)
external_obs.connect()

thread.start()

class ExternalDummyService(Thread):
    def __init__(self):
        self.subject = Subject()

    def run(self):
        for i in range(5):
            dummy_msg = { ... }
            self.subject.on_next(dummy_msg)

def fast_process(msg):
    print("FAST {0} {1}".format(msg["counter"], 1000*(time() - msg["timestamp"])))
    sleep(0.1)

def slow_process(msg):
    print("SLOW {0} {1}".format(msg["counter"], 1000*(time() - msg["timestamp"])))
    sleep(1)

我得到的输出是这个,两个进程都同步运行,并且在两个进程都完成每次执行之前,ExternalDummyService不会发出新值:

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emitting 0
STARTED
SLOW 0 1.0008811950683594
FAST 0 2.0122528076171875
emitting 1
SLOW 1 1.5070438385009766
FAST 1 1.5070438385009766
emitting 2
SLOW 2 0.5052089691162109
FAST 2 0.9891986846923828
emitting 3
SLOW 3 1.0006427764892578
FAST 3 1.0006427764892578
emitting 4
SLOW 4 1.0013580322265625
FAST 4 1.0013580322265625

FINISHED

我想得到这样的东西,服务发出消息而无需等待进程运行和异步运行:

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STARTED
emitting 0
emitting 1
emitting 2
FAST 0 2.0122528076171875
FAST 1 1.5070438385009766
emitting 3
SLOW 0 1.0008811950683594
FAST 2 0.9891986846923828
emitting 4
FAST 3 1.0006427764892578
SLOW 1 1.5070438385009766
FAST 4 1.0013580322265625
SLOW 2 0.5052089691162109
SLOW 3 1.0006427764892578
SLOW 4 1.0013580322265625

FINISHED

我尝试使用share(),ThreadPoolScheduler和其他我没有想法的东西在做事情。

谢谢!


使用以下问题的答案:具有多个订阅者和事件的RxJava并发

...通过以下代码,我已经达到了预期的结果:

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optimal_thread_count = cpu_count()
pool_scheduler = ThreadPoolScheduler(optimal_thread_count)

thread = ExternalDummyService()
external_obs = thread.subject.publish()

external_obs \\
    .flat_map(lambda msg: Observable.just(msg).subscribe_on(pool_scheduler)) \\
    .subscribe(fast_process)

external_obs \\
    .flat_map(lambda msg: Observable.just(msg).subscribe_on(pool_scheduler)) \\
    .subscribe(slow_process)

external_obs.connect()

thread.start()

完整版本:https://pyfiddle.io/fiddle/20f8871c-48d6-4d6b-b1a4-fdd0a4aa6f95/?m =保存的小提琴

输出为:

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emitting 0
emitting 1
emitting 2
emitting 3
emitting 4
FAST 0 52.629709243774414
FAST 1 51.12814903259277
FAST 2 100.2051830291748
FAST 3 151.2434482574463
SLOW 0 503.0245780944824
SLOW 1 502.0263195037842
FAST 4 548.7725734710693
SLOW 2 551.4400005340576
SLOW 3 652.1098613739014
SLOW 4 1000.3445148468018

请随时提出任何改进建议。