klipper-dgus/klippy/queuelogger.py

76 lines
2.6 KiB
Python

# Code to implement asynchronous logging from a background thread
#
# Copyright (C) 2016-2019 Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import logging, logging.handlers, threading, queue, time
# Class to forward all messages through a queue to a background thread
class QueueHandler(logging.Handler):
def __init__(self, queue):
logging.Handler.__init__(self)
self.queue = queue
def emit(self, record):
try:
self.format(record)
record.msg = record.message
record.args = None
record.exc_info = None
self.queue.put_nowait(record)
except Exception:
self.handleError(record)
# Class to poll a queue in a background thread and log each message
class QueueListener(logging.handlers.TimedRotatingFileHandler):
def __init__(self, filename):
logging.handlers.TimedRotatingFileHandler.__init__(
self, filename, when='midnight', backupCount=5)
self.bg_queue = queue.Queue()
self.bg_thread = threading.Thread(target=self._bg_thread)
self.bg_thread.start()
self.rollover_info = {}
def _bg_thread(self):
while 1:
record = self.bg_queue.get(True)
if record is None:
break
self.handle(record)
def stop(self):
self.bg_queue.put_nowait(None)
self.bg_thread.join()
def set_rollover_info(self, name, info):
if info is None:
self.rollover_info.pop(name, None)
return
self.rollover_info[name] = info
def clear_rollover_info(self):
self.rollover_info.clear()
def doRollover(self):
logging.handlers.TimedRotatingFileHandler.doRollover(self)
lines = [self.rollover_info[name]
for name in sorted(self.rollover_info)]
lines.append(
"=============== Log rollover at %s ===============" % (
time.asctime(),))
self.emit(logging.makeLogRecord(
{'msg': "\n".join(lines), 'level': logging.INFO}))
MainQueueHandler = None
def setup_bg_logging(filename, debuglevel):
global MainQueueHandler
ql = QueueListener(filename)
MainQueueHandler = QueueHandler(ql.bg_queue)
root = logging.getLogger()
root.addHandler(MainQueueHandler)
root.setLevel(debuglevel)
return ql
def clear_bg_logging():
global MainQueueHandler
if MainQueueHandler is not None:
root = logging.getLogger()
root.removeHandler(MainQueueHandler)
root.setLevel(logging.WARNING)
MainQueueHandler = None