208 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			208 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			Python
		
	
	
# Copyright 2014-2016 OpenMarket Ltd
 | 
						|
#
 | 
						|
# Licensed under the Apache License, Version 2.0 (the "License");
 | 
						|
# you may not use this file except in compliance with the License.
 | 
						|
# You may obtain a copy of the License at
 | 
						|
#
 | 
						|
#     http://www.apache.org/licenses/LICENSE-2.0
 | 
						|
#
 | 
						|
# Unless required by applicable law or agreed to in writing, software
 | 
						|
# distributed under the License is distributed on an "AS IS" BASIS,
 | 
						|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 | 
						|
# See the License for the specific language governing permissions and
 | 
						|
# limitations under the License.
 | 
						|
 | 
						|
import json
 | 
						|
import logging
 | 
						|
import typing
 | 
						|
from typing import Any, Callable, Dict, Generator, Optional, Sequence
 | 
						|
 | 
						|
import attr
 | 
						|
from frozendict import frozendict
 | 
						|
from matrix_common.versionstring import get_distribution_version_string
 | 
						|
from typing_extensions import ParamSpec
 | 
						|
 | 
						|
from twisted.internet import defer, task
 | 
						|
from twisted.internet.defer import Deferred
 | 
						|
from twisted.internet.interfaces import IDelayedCall, IReactorTime
 | 
						|
from twisted.internet.task import LoopingCall
 | 
						|
from twisted.python.failure import Failure
 | 
						|
 | 
						|
from synapse.logging import context
 | 
						|
 | 
						|
if typing.TYPE_CHECKING:
 | 
						|
    pass
 | 
						|
 | 
						|
logger = logging.getLogger(__name__)
 | 
						|
 | 
						|
 | 
						|
def _reject_invalid_json(val: Any) -> None:
 | 
						|
    """Do not allow Infinity, -Infinity, or NaN values in JSON."""
 | 
						|
    raise ValueError("Invalid JSON value: '%s'" % val)
 | 
						|
 | 
						|
 | 
						|
def _handle_frozendict(obj: Any) -> Dict[Any, Any]:
 | 
						|
    """Helper for json_encoder. Makes frozendicts serializable by returning
 | 
						|
    the underlying dict
 | 
						|
    """
 | 
						|
    if type(obj) is frozendict:
 | 
						|
        # fishing the protected dict out of the object is a bit nasty,
 | 
						|
        # but we don't really want the overhead of copying the dict.
 | 
						|
        try:
 | 
						|
            # Safety: we catch the AttributeError immediately below.
 | 
						|
            # See https://github.com/matrix-org/python-canonicaljson/issues/36#issuecomment-927816293
 | 
						|
            # for discussion on how frozendict's internals have changed over time.
 | 
						|
            return obj._dict  # type: ignore[attr-defined]
 | 
						|
        except AttributeError:
 | 
						|
            # When the C implementation of frozendict is used,
 | 
						|
            # there isn't a `_dict` attribute with a dict
 | 
						|
            # so we resort to making a copy of the frozendict
 | 
						|
            return dict(obj)
 | 
						|
    raise TypeError(
 | 
						|
        "Object of type %s is not JSON serializable" % obj.__class__.__name__
 | 
						|
    )
 | 
						|
 | 
						|
 | 
						|
# A custom JSON encoder which:
 | 
						|
#   * handles frozendicts
 | 
						|
#   * produces valid JSON (no NaNs etc)
 | 
						|
#   * reduces redundant whitespace
 | 
						|
json_encoder = json.JSONEncoder(
 | 
						|
    allow_nan=False, separators=(",", ":"), default=_handle_frozendict
 | 
						|
)
 | 
						|
 | 
						|
# Create a custom decoder to reject Python extensions to JSON.
 | 
						|
json_decoder = json.JSONDecoder(parse_constant=_reject_invalid_json)
 | 
						|
 | 
						|
 | 
						|
def unwrapFirstError(failure: Failure) -> Failure:
 | 
						|
    # Deprecated: you probably just want to catch defer.FirstError and reraise
 | 
						|
    # the subFailure's value, which will do a better job of preserving stacktraces.
 | 
						|
    # (actually, you probably want to use yieldable_gather_results anyway)
 | 
						|
    failure.trap(defer.FirstError)
 | 
						|
    return failure.value.subFailure  # type: ignore[union-attr]  # Issue in Twisted's annotations
 | 
						|
 | 
						|
 | 
						|
P = ParamSpec("P")
 | 
						|
 | 
						|
 | 
						|
@attr.s(slots=True)
 | 
						|
class Clock:
 | 
						|
    """
 | 
						|
    A Clock wraps a Twisted reactor and provides utilities on top of it.
 | 
						|
 | 
						|
    Args:
 | 
						|
        reactor: The Twisted reactor to use.
 | 
						|
    """
 | 
						|
 | 
						|
    _reactor: IReactorTime = attr.ib()
 | 
						|
 | 
						|
    @defer.inlineCallbacks  # type: ignore[arg-type]  # Issue in Twisted's type annotations
 | 
						|
    def sleep(self, seconds: float) -> "Generator[Deferred[float], Any, Any]":
 | 
						|
        d: defer.Deferred[float] = defer.Deferred()
 | 
						|
        with context.PreserveLoggingContext():
 | 
						|
            self._reactor.callLater(seconds, d.callback, seconds)
 | 
						|
            res = yield d
 | 
						|
        return res
 | 
						|
 | 
						|
    def time(self) -> float:
 | 
						|
        """Returns the current system time in seconds since epoch."""
 | 
						|
        return self._reactor.seconds()
 | 
						|
 | 
						|
    def time_msec(self) -> int:
 | 
						|
        """Returns the current system time in milliseconds since epoch."""
 | 
						|
        return int(self.time() * 1000)
 | 
						|
 | 
						|
    def looping_call(
 | 
						|
        self, f: Callable[P, object], msec: float, *args: P.args, **kwargs: P.kwargs
 | 
						|
    ) -> LoopingCall:
 | 
						|
        """Call a function repeatedly.
 | 
						|
 | 
						|
        Waits `msec` initially before calling `f` for the first time.
 | 
						|
 | 
						|
        Note that the function will be called with no logcontext, so if it is anything
 | 
						|
        other than trivial, you probably want to wrap it in run_as_background_process.
 | 
						|
 | 
						|
        Args:
 | 
						|
            f: The function to call repeatedly.
 | 
						|
            msec: How long to wait between calls in milliseconds.
 | 
						|
            *args: Postional arguments to pass to function.
 | 
						|
            **kwargs: Key arguments to pass to function.
 | 
						|
        """
 | 
						|
        call = task.LoopingCall(f, *args, **kwargs)
 | 
						|
        call.clock = self._reactor
 | 
						|
        d = call.start(msec / 1000.0, now=False)
 | 
						|
        d.addErrback(log_failure, "Looping call died", consumeErrors=False)
 | 
						|
        return call
 | 
						|
 | 
						|
    def call_later(
 | 
						|
        self, delay: float, callback: Callable, *args: Any, **kwargs: Any
 | 
						|
    ) -> IDelayedCall:
 | 
						|
        """Call something later
 | 
						|
 | 
						|
        Note that the function will be called with no logcontext, so if it is anything
 | 
						|
        other than trivial, you probably want to wrap it in run_as_background_process.
 | 
						|
 | 
						|
        Args:
 | 
						|
            delay: How long to wait in seconds.
 | 
						|
            callback: Function to call
 | 
						|
            *args: Postional arguments to pass to function.
 | 
						|
            **kwargs: Key arguments to pass to function.
 | 
						|
        """
 | 
						|
 | 
						|
        def wrapped_callback(*args: Any, **kwargs: Any) -> None:
 | 
						|
            with context.PreserveLoggingContext():
 | 
						|
                callback(*args, **kwargs)
 | 
						|
 | 
						|
        with context.PreserveLoggingContext():
 | 
						|
            return self._reactor.callLater(delay, wrapped_callback, *args, **kwargs)
 | 
						|
 | 
						|
    def cancel_call_later(self, timer: IDelayedCall, ignore_errs: bool = False) -> None:
 | 
						|
        try:
 | 
						|
            timer.cancel()
 | 
						|
        except Exception:
 | 
						|
            if not ignore_errs:
 | 
						|
                raise
 | 
						|
 | 
						|
 | 
						|
def log_failure(
 | 
						|
    failure: Failure, msg: str, consumeErrors: bool = True
 | 
						|
) -> Optional[Failure]:
 | 
						|
    """Creates a function suitable for passing to `Deferred.addErrback` that
 | 
						|
    logs any failures that occur.
 | 
						|
 | 
						|
    Args:
 | 
						|
        failure: The Failure to log
 | 
						|
        msg: Message to log
 | 
						|
        consumeErrors: If true consumes the failure, otherwise passes on down
 | 
						|
            the callback chain
 | 
						|
 | 
						|
    Returns:
 | 
						|
        The Failure if consumeErrors is false. None, otherwise.
 | 
						|
    """
 | 
						|
 | 
						|
    logger.error(
 | 
						|
        msg, exc_info=(failure.type, failure.value, failure.getTracebackObject())  # type: ignore[arg-type]
 | 
						|
    )
 | 
						|
 | 
						|
    if not consumeErrors:
 | 
						|
        return failure
 | 
						|
    return None
 | 
						|
 | 
						|
 | 
						|
# Version string with git info. Computed here once so that we don't invoke git multiple
 | 
						|
# times.
 | 
						|
SYNAPSE_VERSION = get_distribution_version_string("matrix-synapse", __file__)
 | 
						|
 | 
						|
 | 
						|
class ExceptionBundle(Exception):
 | 
						|
    # A poor stand-in for something like Python 3.11's ExceptionGroup.
 | 
						|
    # (A backport called `exceptiongroup` exists but seems overkill: we just want a
 | 
						|
    # container type here.)
 | 
						|
    def __init__(self, message: str, exceptions: Sequence[Exception]):
 | 
						|
        parts = [message]
 | 
						|
        for e in exceptions:
 | 
						|
            parts.append(str(e))
 | 
						|
        super().__init__("\n  - ".join(parts))
 | 
						|
        self.exceptions = exceptions
 |