278 lines
8.9 KiB
Python
278 lines
8.9 KiB
Python
# Copyright 2014, 2015 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.
|
|
|
|
from twisted.internet import defer
|
|
|
|
import threading
|
|
import logging
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
try:
|
|
import resource
|
|
|
|
# Python doesn't ship with a definition of RUSAGE_THREAD but it's defined
|
|
# to be 1 on linux so we hard code it.
|
|
RUSAGE_THREAD = 1
|
|
|
|
# If the system doesn't support RUSAGE_THREAD then this should throw an
|
|
# exception.
|
|
resource.getrusage(RUSAGE_THREAD)
|
|
|
|
def get_thread_resource_usage():
|
|
return resource.getrusage(RUSAGE_THREAD)
|
|
except:
|
|
# If the system doesn't support resource.getrusage(RUSAGE_THREAD) then we
|
|
# won't track resource usage by returning None.
|
|
def get_thread_resource_usage():
|
|
return None
|
|
|
|
|
|
class LoggingContext(object):
|
|
"""Additional context for log formatting. Contexts are scoped within a
|
|
"with" block. Contexts inherit the state of their parent contexts.
|
|
Args:
|
|
name (str): Name for the context for debugging.
|
|
"""
|
|
|
|
__slots__ = [
|
|
"parent_context", "name", "usage_start", "usage_end", "main_thread", "__dict__"
|
|
]
|
|
|
|
thread_local = threading.local()
|
|
|
|
class Sentinel(object):
|
|
"""Sentinel to represent the root context"""
|
|
|
|
__slots__ = []
|
|
|
|
def __str__(self):
|
|
return "sentinel"
|
|
|
|
def copy_to(self, record):
|
|
pass
|
|
|
|
def start(self):
|
|
pass
|
|
|
|
def stop(self):
|
|
pass
|
|
|
|
sentinel = Sentinel()
|
|
|
|
def __init__(self, name=None):
|
|
self.parent_context = None
|
|
self.name = name
|
|
self.ru_stime = 0.
|
|
self.ru_utime = 0.
|
|
self.usage_start = None
|
|
self.main_thread = threading.current_thread()
|
|
|
|
def __str__(self):
|
|
return "%s@%x" % (self.name, id(self))
|
|
|
|
@classmethod
|
|
def current_context(cls):
|
|
"""Get the current logging context from thread local storage"""
|
|
return getattr(cls.thread_local, "current_context", cls.sentinel)
|
|
|
|
@classmethod
|
|
def set_current_context(cls, context):
|
|
"""Set the current logging context in thread local storage
|
|
Args:
|
|
context(LoggingContext): The context to activate.
|
|
Returns:
|
|
The context that was previously active
|
|
"""
|
|
current = cls.current_context()
|
|
if current is not context:
|
|
current.stop()
|
|
cls.thread_local.current_context = context
|
|
context.start()
|
|
return current
|
|
|
|
def __enter__(self):
|
|
"""Enters this logging context into thread local storage"""
|
|
if self.parent_context is not None:
|
|
raise Exception("Attempt to enter logging context multiple times")
|
|
self.parent_context = self.set_current_context(self)
|
|
return self
|
|
|
|
def __exit__(self, type, value, traceback):
|
|
"""Restore the logging context in thread local storage to the state it
|
|
was before this context was entered.
|
|
Returns:
|
|
None to avoid suppressing any exeptions that were thrown.
|
|
"""
|
|
current = self.set_current_context(self.parent_context)
|
|
if current is not self:
|
|
if current is self.sentinel:
|
|
logger.debug("Expected logging context %s has been lost", self)
|
|
else:
|
|
logger.warn(
|
|
"Current logging context %s is not expected context %s",
|
|
current,
|
|
self
|
|
)
|
|
self.parent_context = None
|
|
|
|
def __getattr__(self, name):
|
|
"""Delegate member lookup to parent context"""
|
|
return getattr(self.parent_context, name)
|
|
|
|
def copy_to(self, record):
|
|
"""Copy fields from this context and its parents to the record"""
|
|
if self.parent_context is not None:
|
|
self.parent_context.copy_to(record)
|
|
for key, value in self.__dict__.items():
|
|
setattr(record, key, value)
|
|
|
|
record.ru_utime, record.ru_stime = self.get_resource_usage()
|
|
|
|
def start(self):
|
|
if threading.current_thread() is not self.main_thread:
|
|
return
|
|
|
|
if self.usage_start and self.usage_end:
|
|
self.ru_utime += self.usage_end.ru_utime - self.usage_start.ru_utime
|
|
self.ru_stime += self.usage_end.ru_stime - self.usage_start.ru_stime
|
|
self.usage_start = None
|
|
self.usage_end = None
|
|
|
|
if not self.usage_start:
|
|
self.usage_start = get_thread_resource_usage()
|
|
|
|
def stop(self):
|
|
if threading.current_thread() is not self.main_thread:
|
|
return
|
|
|
|
if self.usage_start:
|
|
self.usage_end = get_thread_resource_usage()
|
|
|
|
def get_resource_usage(self):
|
|
ru_utime = self.ru_utime
|
|
ru_stime = self.ru_stime
|
|
|
|
if self.usage_start and threading.current_thread() is self.main_thread:
|
|
current = get_thread_resource_usage()
|
|
ru_utime += current.ru_utime - self.usage_start.ru_utime
|
|
ru_stime += current.ru_stime - self.usage_start.ru_stime
|
|
|
|
return ru_utime, ru_stime
|
|
|
|
|
|
class LoggingContextFilter(logging.Filter):
|
|
"""Logging filter that adds values from the current logging context to each
|
|
record.
|
|
Args:
|
|
**defaults: Default values to avoid formatters complaining about
|
|
missing fields
|
|
"""
|
|
def __init__(self, **defaults):
|
|
self.defaults = defaults
|
|
|
|
def filter(self, record):
|
|
"""Add each fields from the logging contexts to the record.
|
|
Returns:
|
|
True to include the record in the log output.
|
|
"""
|
|
context = LoggingContext.current_context()
|
|
for key, value in self.defaults.items():
|
|
setattr(record, key, value)
|
|
context.copy_to(record)
|
|
return True
|
|
|
|
|
|
class PreserveLoggingContext(object):
|
|
"""Captures the current logging context and restores it when the scope is
|
|
exited. Used to restore the context after a function using
|
|
@defer.inlineCallbacks is resumed by a callback from the reactor."""
|
|
|
|
__slots__ = ["current_context", "new_context"]
|
|
|
|
def __init__(self, new_context=LoggingContext.sentinel):
|
|
self.new_context = new_context
|
|
|
|
def __enter__(self):
|
|
"""Captures the current logging context"""
|
|
self.current_context = LoggingContext.set_current_context(
|
|
self.new_context
|
|
)
|
|
|
|
def __exit__(self, type, value, traceback):
|
|
"""Restores the current logging context"""
|
|
LoggingContext.set_current_context(self.current_context)
|
|
if self.current_context is not LoggingContext.sentinel:
|
|
if self.current_context.parent_context is None:
|
|
logger.warn(
|
|
"Restoring dead context: %s",
|
|
self.current_context,
|
|
)
|
|
|
|
|
|
class _PreservingContextDeferred(defer.Deferred):
|
|
"""A deferred that ensures that all callbacks and errbacks are called with
|
|
the given logging context.
|
|
"""
|
|
def __init__(self, context):
|
|
self._log_context = context
|
|
defer.Deferred.__init__(self)
|
|
|
|
def addCallbacks(self, callback, errback=None,
|
|
callbackArgs=None, callbackKeywords=None,
|
|
errbackArgs=None, errbackKeywords=None):
|
|
callback = self._wrap_callback(callback)
|
|
errback = self._wrap_callback(errback)
|
|
return defer.Deferred.addCallbacks(
|
|
self, callback,
|
|
errback=errback,
|
|
callbackArgs=callbackArgs,
|
|
callbackKeywords=callbackKeywords,
|
|
errbackArgs=errbackArgs,
|
|
errbackKeywords=errbackKeywords,
|
|
)
|
|
|
|
def _wrap_callback(self, f):
|
|
def g(res, *args, **kwargs):
|
|
with PreserveLoggingContext(self._log_context):
|
|
res = f(res, *args, **kwargs)
|
|
return res
|
|
return g
|
|
|
|
|
|
def preserve_context_over_fn(fn, *args, **kwargs):
|
|
"""Takes a function and invokes it with the given arguments, but removes
|
|
and restores the current logging context while doing so.
|
|
|
|
If the result is a deferred, call preserve_context_over_deferred before
|
|
returning it.
|
|
"""
|
|
with PreserveLoggingContext():
|
|
res = fn(*args, **kwargs)
|
|
|
|
if isinstance(res, defer.Deferred):
|
|
return preserve_context_over_deferred(res)
|
|
else:
|
|
return res
|
|
|
|
|
|
def preserve_context_over_deferred(deferred):
|
|
"""Given a deferred wrap it such that any callbacks added later to it will
|
|
be invoked with the current context.
|
|
"""
|
|
current_context = LoggingContext.current_context()
|
|
d = _PreservingContextDeferred(current_context)
|
|
deferred.chainDeferred(d)
|
|
return d
|