112 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			112 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Python
		
	
	
| # -*- coding: utf-8 -*-
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| # Copyright 2014-2016 OpenMarket Ltd
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| #
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| # Licensed under the Apache License, Version 2.0 (the "License");
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| # you may not use this file except in compliance with the License.
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| # You may obtain a copy of the License at
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| #
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| #     http://www.apache.org/licenses/LICENSE-2.0
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| #
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| # Unless required by applicable law or agreed to in writing, software
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| # distributed under the License is distributed on an "AS IS" BASIS,
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| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| # See the License for the specific language governing permissions and
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| # limitations under the License.
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| 
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| import logging
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| from itertools import islice
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| 
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| import attr
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| 
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| from twisted.internet import defer, task
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| 
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| from synapse.util.logcontext import PreserveLoggingContext
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| 
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| logger = logging.getLogger(__name__)
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| 
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| 
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| def unwrapFirstError(failure):
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|     # defer.gatherResults and DeferredLists wrap failures.
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|     failure.trap(defer.FirstError)
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|     return failure.value.subFailure
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| 
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| 
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| @attr.s
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| class Clock(object):
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|     """
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|     A Clock wraps a Twisted reactor and provides utilities on top of it.
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| 
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|     Args:
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|         reactor: The Twisted reactor to use.
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|     """
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|     _reactor = attr.ib()
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| 
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|     @defer.inlineCallbacks
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|     def sleep(self, seconds):
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|         d = defer.Deferred()
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|         with PreserveLoggingContext():
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|             self._reactor.callLater(seconds, d.callback, seconds)
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|             res = yield d
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|         defer.returnValue(res)
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| 
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|     def time(self):
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|         """Returns the current system time in seconds since epoch."""
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|         return self._reactor.seconds()
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| 
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|     def time_msec(self):
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|         """Returns the current system time in miliseconds since epoch."""
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|         return int(self.time() * 1000)
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| 
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|     def looping_call(self, f, msec):
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|         """Call a function repeatedly.
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| 
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|          Waits `msec` initially before calling `f` for the first time.
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| 
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|         Args:
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|             f(function): The function to call repeatedly.
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|             msec(float): How long to wait between calls in milliseconds.
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|         """
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|         call = task.LoopingCall(f)
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|         call.clock = self._reactor
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|         call.start(msec / 1000.0, now=False)
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|         return call
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| 
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|     def call_later(self, delay, callback, *args, **kwargs):
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|         """Call something later
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| 
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|         Args:
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|             delay(float): How long to wait in seconds.
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|             callback(function): Function to call
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|             *args: Postional arguments to pass to function.
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|             **kwargs: Key arguments to pass to function.
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|         """
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|         def wrapped_callback(*args, **kwargs):
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|             with PreserveLoggingContext():
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|                 callback(*args, **kwargs)
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| 
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|         with PreserveLoggingContext():
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|             return self._reactor.callLater(delay, wrapped_callback, *args, **kwargs)
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| 
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|     def cancel_call_later(self, timer, ignore_errs=False):
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|         try:
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|             timer.cancel()
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|         except Exception:
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|             if not ignore_errs:
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|                 raise
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| 
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| 
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| def batch_iter(iterable, size):
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|     """batch an iterable up into tuples with a maximum size
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| 
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|     Args:
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|         iterable (iterable): the iterable to slice
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|         size (int): the maximum batch size
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| 
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|     Returns:
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|         an iterator over the chunks
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|     """
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|     # make sure we can deal with iterables like lists too
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|     sourceiter = iter(iterable)
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|     # call islice until it returns an empty tuple
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|     return iter(lambda: tuple(islice(sourceiter, size)), ())
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