Pep8 and a few doc strings

This commit is contained in:
Mark Haines 2014-10-30 10:13:46 +00:00
parent b29517bd01
commit fa955cc2a4
2 changed files with 40 additions and 17 deletions

View File

@ -19,6 +19,7 @@ from twisted.python.log import PythonLoggingObserver
import logging
import logging.config
class LoggingConfig(Config):
def __init__(self, args):
super(LoggingConfig, self).__init__(args)
@ -62,7 +63,6 @@ class LoggingConfig(Config):
handler = logging.FileHandler(self.log_file)
else:
handler = logging.StreamHandler()
print handler
handler.setFormatter(formatter)
handler.addFilter(LoggingContextFilter(request=""))

View File

@ -1,15 +1,23 @@
from functools import wraps
import threading
import logging
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", "__dict__"]
thread_local = threading.local()
class Sentinel(object):
"""Sentinel to represent the root context"""
__slots__ = []
def copy_to(self, record):
pass
@ -24,9 +32,11 @@ class LoggingContext(object):
@classmethod
def current_context(cls):
"""Get the current logging context from thread local storage"""
return getattr(cls.thread_local, "current_context", cls.sentinel)
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.current_context()
@ -34,6 +44,11 @@ class LoggingContext(object):
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.
"""
if self.thread_local.current_context is not self:
logging.error(
"Current logging context %s is not the expected context %s",
@ -44,29 +59,32 @@ class LoggingContext(object):
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)
@classmethod
def wrap_callback(cls, callback):
context = cls.current_context()
@wraps(callback)
def wrapped(*args, **kargs):
cls.thread_local.current_context = context
return callback(*args, **kargs)
return wrapped
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)
@ -75,11 +93,16 @@ class LoggingContextFilter(logging.Filter):
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"]
def __enter__(self):
"""Captures the current logging context"""
self.current_context = LoggingContext.current_context()
def __exit__(self, type, value, traceback):
"""Restores the current logging context"""
LoggingContext.thread_local.current_context = self.current_context