191 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			191 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			Python
		
	
	
| # 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 json
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| import logging
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| import typing
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| from typing import Any, Callable, Dict, Generator, Optional
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| 
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| import attr
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| from frozendict import frozendict
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| 
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| from twisted.internet import defer, task
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| from twisted.internet.defer import Deferred
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| from twisted.internet.interfaces import IDelayedCall, IReactorTime
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| from twisted.internet.task import LoopingCall
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| from twisted.python.failure import Failure
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| 
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| from synapse.logging import context
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| 
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| if typing.TYPE_CHECKING:
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|     pass
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| 
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| # FIXME Mjolnir imports glob_to_regex from this file, but it was moved to
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| #       matrix_common.
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| #       As a temporary workaround, we import glob_to_regex here for
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| #       compatibility with current versions of Mjolnir.
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| # See https://github.com/matrix-org/mjolnir/pull/174
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| from matrix_common.regex import glob_to_regex  # noqa
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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 _reject_invalid_json(val: Any) -> None:
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|     """Do not allow Infinity, -Infinity, or NaN values in JSON."""
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|     raise ValueError("Invalid JSON value: '%s'" % val)
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| 
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| 
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| def _handle_frozendict(obj: Any) -> Dict[Any, Any]:
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|     """Helper for json_encoder. Makes frozendicts serializable by returning
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|     the underlying dict
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|     """
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|     if type(obj) is frozendict:
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|         # fishing the protected dict out of the object is a bit nasty,
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|         # but we don't really want the overhead of copying the dict.
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|         try:
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|             # Safety: we catch the AttributeError immediately below.
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|             # See https://github.com/matrix-org/python-canonicaljson/issues/36#issuecomment-927816293
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|             # for discussion on how frozendict's internals have changed over time.
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|             return obj._dict  # type: ignore[attr-defined]
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|         except AttributeError:
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|             # When the C implementation of frozendict is used,
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|             # there isn't a `_dict` attribute with a dict
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|             # so we resort to making a copy of the frozendict
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|             return dict(obj)
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|     raise TypeError(
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|         "Object of type %s is not JSON serializable" % obj.__class__.__name__
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|     )
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| 
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| 
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| # A custom JSON encoder which:
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| #   * handles frozendicts
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| #   * produces valid JSON (no NaNs etc)
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| #   * reduces redundant whitespace
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| json_encoder = json.JSONEncoder(
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|     allow_nan=False, separators=(",", ":"), default=_handle_frozendict
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| )
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| 
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| # Create a custom decoder to reject Python extensions to JSON.
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| json_decoder = json.JSONDecoder(parse_constant=_reject_invalid_json)
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| 
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| 
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| def unwrapFirstError(failure: Failure) -> 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  # type: ignore[union-attr]  # Issue in Twisted's annotations
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| 
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| 
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| @attr.s(slots=True)
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| class Clock:
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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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| 
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|     _reactor: IReactorTime = attr.ib()
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| 
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|     @defer.inlineCallbacks  # type: ignore[arg-type]  # Issue in Twisted's type annotations
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|     def sleep(self, seconds: float) -> "Generator[Deferred[float], Any, Any]":
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|         d: defer.Deferred[float] = defer.Deferred()
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|         with context.PreserveLoggingContext():
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|             self._reactor.callLater(seconds, d.callback, seconds)
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|             res = yield d
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|         return res
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| 
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|     def time(self) -> float:
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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) -> int:
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|         """Returns the current system time in milliseconds since epoch."""
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|         return int(self.time() * 1000)
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| 
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|     def looping_call(
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|         self, f: Callable, msec: float, *args: Any, **kwargs: Any
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|     ) -> LoopingCall:
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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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|         Note that the function will be called with no logcontext, so if it is anything
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|         other than trivial, you probably want to wrap it in run_as_background_process.
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| 
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|         Args:
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|             f: The function to call repeatedly.
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|             msec: How long to wait between calls in milliseconds.
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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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|         call = task.LoopingCall(f, *args, **kwargs)
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|         call.clock = self._reactor
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|         d = call.start(msec / 1000.0, now=False)
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|         d.addErrback(log_failure, "Looping call died", consumeErrors=False)
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|         return call
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| 
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|     def call_later(
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|         self, delay: float, callback: Callable, *args: Any, **kwargs: Any
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|     ) -> IDelayedCall:
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|         """Call something later
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| 
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|         Note that the function will be called with no logcontext, so if it is anything
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|         other than trivial, you probably want to wrap it in run_as_background_process.
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| 
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|         Args:
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|             delay: How long to wait in seconds.
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|             callback: 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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| 
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|         def wrapped_callback(*args: Any, **kwargs: Any) -> None:
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|             with context.PreserveLoggingContext():
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|                 callback(*args, **kwargs)
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| 
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|         with context.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: IDelayedCall, ignore_errs: bool = False) -> None:
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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 log_failure(
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|     failure: Failure, msg: str, consumeErrors: bool = True
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| ) -> Optional[Failure]:
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|     """Creates a function suitable for passing to `Deferred.addErrback` that
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|     logs any failures that occur.
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| 
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|     Args:
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|         failure: The Failure to log
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|         msg: Message to log
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|         consumeErrors: If true consumes the failure, otherwise passes on down
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|             the callback chain
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| 
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|     Returns:
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|         The Failure if consumeErrors is false. None, otherwise.
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|     """
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| 
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|     logger.error(
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|         msg, exc_info=(failure.type, failure.value, failure.getTracebackObject())  # type: ignore[arg-type]
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|     )
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| 
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|     if not consumeErrors:
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|         return failure
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|     return None
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