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Diffstat (limited to '')
| -rw-r--r-- | synapse/logging/scopecontextmanager.py | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/synapse/logging/scopecontextmanager.py b/synapse/logging/scopecontextmanager.py new file mode 100644 index 0000000000..91e14462f3 --- /dev/null +++ b/synapse/logging/scopecontextmanager.py @@ -0,0 +1,140 @@ +# -*- coding: utf-8 -*- +# Copyright 2019 The Matrix.org Foundation C.I.C. +# +# 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 logging + +import logging + +from opentracing import Scope, ScopeManager + +import twisted + +from synapse.logging.context import LoggingContext, nested_logging_context + +logger = logging.getLogger(__name__) + + +class LogContextScopeManager(ScopeManager): + """ + The LogContextScopeManager tracks the active scope in opentracing + by using the log contexts which are native to synapse. This is so + that the basic opentracing api can be used across twisted defereds. + (I would love to break logcontexts and this into an OS package. but + let's wait for twisted's contexts to be released.) + """ + + def __init__(self, config): + # Set the whitelists + logger.info(config.tracer_config) + self._homeserver_whitelist = config.tracer_config["homeserver_whitelist"] + + @property + def active(self): + """ + Returns the currently active Scope which can be used to access the + currently active Scope.span. + If there is a non-null Scope, its wrapped Span + becomes an implicit parent of any newly-created Span at + Tracer.start_active_span() time. + + Return: + (Scope) : the Scope that is active, or None if not + available. + """ + ctx = LoggingContext.current_context() + if ctx is LoggingContext.sentinel: + return None + else: + return ctx.scope + + def activate(self, span, finish_on_close): + """ + Makes a Span active. + Args + span (Span): the span that should become active. + finish_on_close (Boolean): whether Span should be automatically + finished when Scope.close() is called. + + Returns: + Scope to control the end of the active period for + *span*. It is a programming error to neglect to call + Scope.close() on the returned instance. + """ + + enter_logcontext = False + ctx = LoggingContext.current_context() + + if ctx is LoggingContext.sentinel: + # We don't want this scope to affect. + logger.error("Tried to activate scope outside of loggingcontext") + return Scope(None, span) + elif ctx.scope is not None: + # We want the logging scope to look exactly the same so we give it + # a blank suffix + ctx = nested_logging_context("") + enter_logcontext = True + + scope = _LogContextScope(self, span, ctx, enter_logcontext, finish_on_close) + ctx.scope = scope + return scope + + +class _LogContextScope(Scope): + """ + A custom opentracing scope. The only significant difference is that it will + close the log context it's related to if the logcontext was created specifically + for this scope. + """ + + def __init__(self, manager, span, logcontext, enter_logcontext, finish_on_close): + """ + Args: + manager (LogContextScopeManager): + the manager that is responsible for this scope. + span (Span): + the opentracing span which this scope represents the local + lifetime for. + logcontext (LogContext): + the logcontext to which this scope is attached. + enter_logcontext (Boolean): + if True the logcontext will be entered and exited when the scope + is entered and exited respectively + finish_on_close (Boolean): + if True finish the span when the scope is closed + """ + super(_LogContextScope, self).__init__(manager, span) + self.logcontext = logcontext + self._finish_on_close = finish_on_close + self._enter_logcontext = enter_logcontext + + def __enter__(self): + if self._enter_logcontext: + self.logcontext.__enter__() + + def __exit__(self, type, value, traceback): + if type == twisted.internet.defer._DefGen_Return: + super(_LogContextScope, self).__exit__(None, None, None) + else: + super(_LogContextScope, self).__exit__(type, value, traceback) + if self._enter_logcontext: + self.logcontext.__exit__(type, value, traceback) + else: # the logcontext existed before the creation of the scope + self.logcontext.scope = None + + def close(self): + if self.manager.active is not self: + logger.error("Tried to close a none active scope!") + return + + if self._finish_on_close: + self.span.finish() |