#!/usr/bin/env python3
# vim: set encoding=utf-8 tabstop=4 softtabstop=4 shiftwidth=4 expandtab
#########################################################################
# Copyright 2016-2021 Martin Sinn m.sinn@gmx.de
# Parts Copyright 2013 Marcus Popp marcus@popp.mx
#########################################################################
# This file is part of SmartHomeNG.
#
# SmartHomeNG is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# SmartHomeNG is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with SmartHomeNG. If not, see <http://www.gnu.org/licenses/>.
#########################################################################
import time
import logging
import logging.handlers
import logging.config
import calendar
import os
import datetime
import pickle
import re
from pathlib import Path
import collections
import lib.shyaml as shyaml
from lib.constants import YAML_FILE, DEFAULT_FILE, BASE_LOG, DIR_ETC, DIR_VAR
logs_instance = None
[Doku]class Logs():
_logs = {}
logging_levels = {}
root_handler_name = ''
NOTICE_level = 29
DBGHIGH_level = 13
DBGMED_level = 12
DBGLOW_level = 11
_all_handlers_logger_name = '_shng_all_handlers_logger'
_all_handlers = {}
def __init__(self, sh):
self.logger = logging.getLogger(__name__)
global logs_instance
if logs_instance is None:
logs_instance = self
else:
self.logger.error(f"Another instance of Logs class already exists: {logs_instance}")
self._sh = sh
return
[Doku] def add_logging_level(self, description, value):
"""
Adds a new Logging level to the standard python logging
:param description: appearance within logs SYSINFO
:type description: string
:param value: numeric value for the logging level
:type value: int
:param tocall: function name to call for a log with the given level
:type tocall: String, optional, if not given description will be used with lower case
no error checking is performed here for typos, already existing levels or functions
"""
def logForLevel(self, message, *args, **kwargs):
if self.isEnabledFor(value):
self._log(value, message, args, **kwargs)
def logToRoot(message, *args, **kwargs):
logging.log(value, message, *args, **kwargs)
logging.addLevelName(value, description)
setattr(logging, description, value)
setattr(logging.getLoggerClass(), description.lower(), logForLevel)
setattr(logging, description.lower(), logToRoot)
self.logging_levels[value] = description
return
[Doku] def get_shng_logging_levels(self):
"""
Returns a dict of the logging levels, that are defined in SmartHomeNG (key=numeric log level, value=name od loa level)
It is used e.g. by the admin module
:return: dict
"""
return self.logging_levels
[Doku] def initMemLog(self):
"""
This function initializes all needed datastructures to use the 'env.core.log' mem-logger and
the (old) memlog plugin
It adds the handler log_mem (based on the custom lib.log.ShngMemLogHandler) to the root logger
It logs all WARNINGS from all (old) mem-loggers to the root Logger
"""
log_mem = ShngMemLogHandler('env.core.log', maxlen=50, level=logging.WARNING)
# define formatter for 'env.core.log' log
_logdate = "%Y-%m-%d %H:%M:%S"
_logformat = "%(asctime)s %(levelname)-8s %(threadName)-12s %(message)s"
formatter = logging.Formatter(_logformat, _logdate)
log_mem.setFormatter(formatter)
# add handler to root logger
logging.getLogger('').addHandler(log_mem)
return
[Doku] def add_log(self, name, log):
"""
Adds a log (object) to the list of memory logs
:param name: Name of log
:param log: Log object
"""
self._logs[name] = log
[Doku] def return_logs(self):
"""
Function to the list of memory logs
:return: List of logs
:rtype: list
"""
return self._logs
# ---------------------------------------------------------------------------
[Doku] def load_logging_config(self, filename='', ignore_notfound=False):
"""
Load config from logging.yaml to a dict
If logging.yaml does not contain a 'shng_version' key, a backup is created
"""
if not filename:
conf_filename = self._sh.get_config_file(BASE_LOG)
else:
conf_filename = os.path.join(self._sh.get_config_dir(DIR_ETC), filename)
if not conf_filename.endswith(YAML_FILE) and not conf_filename.endswith(DEFAULT_FILE):
conf_filename += YAML_FILE
result = shyaml.yaml_load(conf_filename, ignore_notfound)
return result
[Doku] def save_logging_config(self, logging_config, create_backup=False):
"""
Save dict to logging.yaml
"""
if logging_config is not None:
logging_config['shng_version'] = self._sh.version.split('-')[0][1:]
conf_filename = self._sh.get_config_file(BASE_LOG)
shyaml.yaml_save_roundtrip(conf_filename, logging_config, create_backup=create_backup)
return
[Doku] def load_logging_config_for_edit(self):
"""
Load config from logging.yaml to a dict
If logging.yaml does not contain a 'shng_version' key, a backup is created
"""
#self.etc_dir = self._sh.get_etcdir()
conf_filename = self._sh.get_config_file(BASE_LOG)
logging_config = shyaml.yaml_load_roundtrip(conf_filename)
self.logger.info("load_logging_config_for_edit: shng_version={}".format(logging_config.get('shng_version', None)))
if logging_config.get('shng_version', None) is None:
logging_config['shng_version'] = self._sh.version.split('-')[0][1:]
self.save_logging_config(logging_config, create_backup=True)
return logging_config
[Doku] def add_all_handlers_logger(self, logging_config):
lg = logging_config['loggers'].get(self._all_handlers_logger_name, None)
if lg is None:
logging_config['loggers'][self._all_handlers_logger_name] = {}
lg = logging_config['loggers'].get(self._all_handlers_logger_name, None)
hd = logging_config['loggers'][self._all_handlers_logger_name].get('handlers', None)
if hd is None:
logging_config['loggers'][self._all_handlers_logger_name]['handlers'] = []
hd = logging_config['loggers'][self._all_handlers_logger_name].get('handlers', None)
all_hdlrs = sorted(logging_config['handlers'].keys())
logging_config['loggers'][self._all_handlers_logger_name]['handlers'] = all_hdlrs
return logging_config
[Doku] def get_all_handlernames(self):
if self._all_handlers == {}:
l = logging.getLogger(self._all_handlers_logger_name)
for h in l.handlers:
self._all_handlers[h.name] = h
return sorted(self._all_handlers.keys())
[Doku] def get_handler_by_name(self, handlername):
if self._all_handlers == {}:
self.get_all_handlernames()
return self._all_handlers[handlername]
# -------------------------------------------------------------------------------
[Doku]class Log(collections.deque):
def __init__(self, smarthome, name, mapping, maxlen=40, handler=None):
"""
Class to implement a memory log
As of shng version 1.7a develop this is used in core at bin/smarthome.py and
in plugins memlog, operationlog and visu_websocket
:param smarthome: Dummy, for backwart compatibility
:param name: name of the the log (used in cli plugin and smartVISU)
:param mapping: Kind of a headline for the entry which can be anything
e.g. mappings can be [time, thread, level, message ] and log entry is a
:param maxlen: maximum length of the memory log, defaults to 40
:param handler: Python LoggingHandler that created this instance of a memory log
"""
collections.deque.__init__(self, maxlen=maxlen)
if (mapping is None) or (mapping == []):
self.mapping = ['time', 'thread', 'level', 'message']
else:
self.mapping = mapping
self._sh = logs_instance._sh
self._name = name
self.handler = handler
# Add this log to dict of defined memory logs
logs_instance.add_log(name, self)
[Doku] def add(self, entry):
"""
Adds a log entry to the memory log. If the log already has reached the maximum length, the oldest
entry is removed from the log automatically.
"""
self.appendleft(entry)
for listener in self._sh.return_event_listeners('log'):
listener('log', {'name': self._name, 'log': [dict(zip(self.mapping, entry))]})
[Doku] def last(self, number):
"""
Returns the newest entries of the log
:param number: Number of entries to return
:return: List of log entries
"""
return(list(self)[-number:])
[Doku] def export(self, number):
"""
Returns the newest entries of the log and prepares them with the mapping
:param number: Number of entries to return
:return: List of log entries
"""
return [dict(zip(self.mapping, x)) for x in list(self)[:number]]
[Doku] def clean(self, dt):
"""
Assuming dt to be a datetime: remove all entries that are smaller or equal
to this given datetime from the right side of the queue
"""
while True:
try:
entry = self.pop()
except Exception:
return
if entry[0] > dt:
self.append(entry)
return
[Doku]class DateTimeRotatingFileHandler(logging.StreamHandler):
"""
Handler for logging to file using current date and time information in
the filename. Either placeholders can be used or a standard pattern is used.
Rotating the log file at each `when` beginning.
If backupCount is > 0, when rollover is done, no more than backupCount
files are kept - the oldest ones are deleted.
"""
def __init__(self,
filename,
when='H',
interval=1,
backupCount=0,
encoding=None,
delay=True,
utc=False):
super().__init__()
self._shtime = logs_instance._sh.shtime
logging.Handler.__init__(self)
self._originalname = os.path.basename(filename)
self._fullname = filename
self._fn = os.path.splitext(self._originalname)[0]
self._ext = os.path.splitext(self._originalname)[1]
self.stream = None
self.encoding = encoding
self.delay = delay
self._when = when.upper()
self.backup_count = backupCount
# Current 'when' events supported:
# S - Seconds
# M - Minutes
# H - Hours
# D - Days
# W or W0..W6 - Week
# MO - Month
# Y - Year
# midnight - roll over at midnight
now = self._shtime.now()
if self._when == 'S':
self.time_unit = datetime.timedelta(seconds=1) # one second
self.suffix = "%Y-%m-%d-%H.%M.%S"
self.ext_pat = re.compile(r"^\d{4}\-\d{2}\-\d{2}\-\d{2}\.\d{2}\.\d{2}", re.ASCII)
if self._when == 'M':
self.time_unit = datetime.timedelta(minutes=1) # one minute
self.suffix = "%Y-%m-%d-%H.%M"
self.ext_pat = re.compile(r"^\d{4}\-\d{2}\-\d{2}\-\d{2}\.\d{2}", re.ASCII)
elif self._when == 'H':
self.time_unit = datetime.timedelta(hours=1) # one hour
self.suffix = "%Y-%m-%d-%H"
self.ext_pat = re.compile(r"^\d{4}\-\d{2}\-\d{2}\-\d{2}", re.ASCII)
elif self._when == 'D' or self._when == 'MIDNIGHT':
self.time_unit = datetime.timedelta(days=1) # one day
self.suffix = "%Y-%m-%d"
self.ext_pat = re.compile(r"^\d{4}\-\d{2}\-\d{2}", re.ASCII)
elif self._when.startswith('W'):
day = 0 if len(self._when) == 1 else int(self._when[1:])
days_until_next = (day - now.weekday()) % 7
days_until_next = 7 if days_until_next == 0 else days_until_next
self.time_unit = datetime.timedelta(days=days_until_next) # one week
self.suffix = "%Y-%m-%d"
self.ext_pat = re.compile(r"^\d{4}\-\d{2}\-\d{2}", re.ASCII)
elif self._when == 'MO':
_, days_in_month = calendar.monthrange(now.year, now.month)
self.time_unit = datetime.timedelta(days=days_in_month) # one month
self.suffix = "%Y-%m"
self.ext_pat = re.compile(r"^\d{4}\-\d{2}", re.ASCII)
elif self._when == 'Y':
days_in_year = (datetime.datetime(now.year + 1, 1, 1) - datetime.datetime(now.year, 1, 1)).days
self.time_unit = datetime.timedelta(days=days_in_year) # one year
self.suffix = "%Y"
self.ext_pat = re.compile(r"^\d{4}", re.ASCII)
else:
raise ValueError(f"Invalid rollover interval specified: {self._when}")
self.interval = self.time_unit * interval # multiply by units requested
self.rollover_at = self.next_rollover_time()
self.baseFilename = self.get_filename() # logging to this file
if not delay:
self.stream = self._open()
[Doku] def parseFilename(self, filename) -> str:
now = self._shtime.now()
try:
# replace placeholders by actual datetime
return filename.format(**{'year': now.year, 'month': now.month,
'day': now.day, 'hour': now.hour,
'minute': now.minute, 'intstamp': int(now.timestamp()),
'stamp': now.timestamp()})
except Exception:
return filename
[Doku] def get_filename(self) -> str:
filename = self.parseFilename(self._fullname)
if '{' not in self._originalname:
dirName, _ = os.path.split(filename)
fn = self._fn + '.' + datetime.datetime.now().strftime(self.suffix) + self._ext
filename = os.path.join(dirName, fn)
if self._fullname.startswith("."):
shng_dir = Path(logs_instance._sh.get_basedir())
filename = str((shng_dir / filename).resolve())
dirName, _ = os.path.split(filename)
if not os.path.isdir(dirName):
os.makedirs(dirName)
return filename
[Doku] def close(self):
"""
Closes the stream.
"""
self.acquire()
try:
try:
if self.stream:
try:
self.flush()
finally:
stream = self.stream
self.stream = None
if hasattr(stream, "close"):
stream.close()
finally:
logging.StreamHandler.close(self)
finally:
self.release()
def _open(self):
"""
Open the current base file with encoding.
Return the resulting stream.
"""
return open(self.baseFilename, 'a', encoding=self.encoding)
[Doku] def next_rollover_time(self):
"""
Work out the rollover time based on current time.
"""
t = self._shtime.now()
if self._when == 'S':
t = t.replace(microsecond=0)
elif self._when == 'M':
t = t.replace(second=0, microsecond=0)
elif self._when == 'H':
t = t.replace(minute=0, second=0, microsecond=0)
elif self._when == 'D' or self._when == 'MIDNIGHT' or self._when.startswith('W'):
t = t.replace(hour=0, minute=0, second=0, microsecond=0)
elif self._when == 'MO':
t = t.replace(day=1, hour=0, minute=0, second=0, microsecond=0)
elif self._when == 'Y':
t = t.replace(month=1, day=1, hour=0, minute=0, second=0, microsecond=0)
return t + self.interval
[Doku] def get_files_to_delete(self):
"""
Determine the files to delete when rolling over.
"""
def custom_replace(match):
# Replace based on different patterns
if any(match.group(i) for i in (1, 2, 3)):
return '\d{4}'
elif any(match.group(i) for i in (4, 7, 10, 13)):
return '\d{1,2}'
elif any(match.group(i) for i in (6, 9, 12, 15)):
return '\d{2}'
elif any(match.group(i) for i in (5, 8, 11, 14)):
return '\d{1}'
elif match.group(16):
return '\d+'
else:
return '[0-9.]'
dir_name, base_fname = os.path.split(self.baseFilename)
fileNames = os.listdir(dir_name)
result = []
if '{' in self._originalname:
year = r'{year}'
year2 = r'{year:02}'
year4 = r'{year:04}'
month = r'{month}'
month1 = r'{month:01}'
month2 = r'{month:02}'
day = r'{day}'
day1 = r'{day:01}'
day2 = r'{day:02}'
hour = r'{hour}'
hour1 = r'{hour:01}'
hour2 = r'{hour:02}'
minute = r'{minute}'
minute1 = r'{minute:01}'
minute2 = r'{minute:02}'
intstamp = r'{intstamp}'
stamp = r'{stamp}'
combined_pattern = f'({year})|({year2})|({year4})|({month})'\
f'|({month1})|({month2})|({day})|({day1})|({day2})|({hour})'\
f'|({hour1})|({hour2})|({minute})|({minute1})|({minute2})|({intstamp})|({stamp})'
regex_result = re.sub(combined_pattern, custom_replace, self._originalname)
pattern_regex = re.compile(regex_result)
for fileName in fileNames:
if pattern_regex.match(fileName):
result.append(os.path.join(dir_name, fileName))
else:
prefix = self._fn + "."
plen = len(prefix)
elen = len(self._ext) * -1
for fileName in fileNames:
cond1 = fileName.startswith(prefix)
cond2 = self.ext_pat.match(fileName[plen:elen])
cond3 = fileName.endswith(self._ext)
if cond1 and cond2 and cond3:
result.append(os.path.join(dir_name, fileName))
if len(result) < self.backup_count:
result = []
else:
result.sort()
result = result[:len(result) - self.backup_count]
return result
[Doku] def do_rollover(self):
"""
Do a rollover. In this case, the current stream will be closed and a new
filename will be generated when the rollover happens.
If there is a backup count, then we have to get a list of matching
filenames, sort them and remove the one with the oldest suffix.
"""
if self.stream:
self.stream.close()
self.stream = None
self.rollover_at = self.next_rollover_time()
self.baseFilename = self.get_filename()
if self.backup_count > 0:
for s in self.get_files_to_delete():
os.remove(s)
if not self.delay:
self.stream = self._open()
[Doku] def emit(self, record):
"""
Emit a record.
Output the record to the file, catering for rollover as described
in do_rollover().
"""
try:
if self._shtime.now() >= self.rollover_at:
self.do_rollover()
if self.stream is None:
self.stream = self._open()
logging.StreamHandler.emit(self, record)
except Exception:
self.handleError(record)
# ================================================================================
"""
In the following part of the code, logging handlers are defined
"""
[Doku]class ShngTimedRotatingFileHandler(logging.handlers.TimedRotatingFileHandler):
"""
TimedRotatingFilehandler with a different naming scheme for rotated files
"""
def __init__(self, filename, when='MIDNIGHT', interval=1, backupCount=0, encoding=None, delay=False, utc=False):
year = datetime.datetime.now().strftime("%Y")
month = datetime.datetime.now().strftime("%m")
day = datetime.datetime.now().strftime("%d")
hour = datetime.datetime.now().strftime("%H")
stamp = datetime.datetime.now().timestamp()
try:
filename = eval(f"f'{filename}'")
except Exception:
pass
super().__init__(filename, when, interval, backupCount, encoding, delay, utc)
[Doku] def getFilesToDelete(self):
"""
Determine the files to delete when rolling over.
More specific than the earlier method, which just used glob.glob().
"""
dirName, baseName = os.path.split(self.baseFilename)
# for changed naming scheme
fName, fExt = os.path.splitext(baseName)
fileNames = os.listdir(dirName)
result = []
# for changed naming scheme
#prefix = baseName + "."
prefix = fName + "."
plen = len(prefix)
# for changed naming scheme
# for fileName in fileNames:
# if fileName[:plen] == prefix:
# suffix = fileName[plen:]
# if self.extMatch.match(suffix):
# result.append(os.path.join(dirName, fileName))
elen = len(fExt)
for fileName in fileNames:
if fileName[:plen] == prefix and fileName[-elen:] == fExt:
if plen + elen < len(fileName):
# ...
suffix = fileName[plen:]
if self.extMatch.match(suffix):
result.append(os.path.join(dirName, fileName))
# ...
#result.append(os.path.join(dirName, fileName))
if len(result) < self.backupCount:
result = []
else:
result.sort()
result = result[:len(result) - self.backupCount]
return result
[Doku] def doRollover(self):
"""
do a rollover; in this case, a date/time stamp is appended to the filename
when the rollover happens. However, you want the file to be named for the
start of the interval, not the current time. If there is a backup count,
then we have to get a list of matching filenames, sort them and remove
the one with the oldest suffix.
"""
if self.stream:
self.stream.close()
self.stream = None
# get the time that this sequence started at and make it a TimeTuple
currentTime = int(time.time())
dstNow = time.localtime(currentTime)[-1]
t = self.rolloverAt - self.interval
if self.utc:
timeTuple = time.gmtime(t)
else:
timeTuple = time.localtime(t)
dstThen = timeTuple[-1]
if dstNow != dstThen:
if dstNow:
addend = 3600
else:
addend = -3600
timeTuple = time.localtime(t + addend)
# from logging.handlers.TimedRotatingFileHandler
#dfn = self.rotation_filename(self.baseFilename + "." +
# time.strftime(self.suffix, timeTuple))
# for shng: splitext -> tuple ( path+fn , ext )
bfn = os.path.splitext(self.baseFilename)[0]
ext = os.path.splitext(self.baseFilename)[1]
dfn = self.rotation_filename(bfn + "." + time.strftime(self.suffix, timeTuple) + ext)
if os.path.exists(dfn):
os.remove(dfn)
self.rotate(self.baseFilename, dfn)
if self.backupCount > 0:
for s in self.getFilesToDelete():
os.remove(s)
if not self.delay:
self.stream = self._open()
newRolloverAt = self.computeRollover(currentTime)
while newRolloverAt <= currentTime:
newRolloverAt = newRolloverAt + self.interval
#If DST changes and midnight or weekly rollover, adjust for this.
if (self.when == 'MIDNIGHT' or self.when.startswith('W')) and not self.utc:
dstAtRollover = time.localtime(newRolloverAt)[-1]
if dstNow != dstAtRollover:
if not dstNow: # DST kicks in before next rollover, so we need to deduct an hour
addend = -3600
else: # DST bows out before next rollover, so we need to add an hour
addend = 3600
newRolloverAt += addend
self.rolloverAt = newRolloverAt
[Doku]class ShngMemLogHandler(logging.StreamHandler):
"""
LogHandler used by MemLog
"""
def __init__(self, logname='undefined', maxlen=35, level=logging.NOTSET,
mapping=['time', 'thread', 'level', 'message'], cache=False):
super().__init__()
self.setLevel(level)
if self.get_name() is None:
# for 'env.core.log' memory logger
self.set_name('_shng_root_memory')
#logs_instance.logger.info(f"ShngMemLogHandler.__init__(): logname={logname}, self={self}, handlername={self.get_name()}, level={self.level}, levelname={logging.getLevelName(self.level)}, maxlen={maxlen}")
self._log = Log(self, logname, mapping, maxlen=maxlen, handler=self)
self._shtime = logs_instance._sh.shtime
# Dummy baseFileName for output in shngadmin (and priv_develop plugin)
self.baseFilename = "'" + self._log._name + "'"
self._cache = cache
self._maxlen = maxlen
# save cache files in var/log/cache directory
cache_directory = os.path.join(logs_instance._sh.get_config_dir(DIR_VAR), 'log'+os.path.sep, 'cache'+os.path.sep)
if cache is True:
if not os.path.isdir(cache_directory):
os.makedirs(cache_directory)
self._cachefile = cache_directory + self._log._name
try:
self.__last_change, self._logcache = self._cache_read(self._cachefile, self._shtime.tzinfo())
self.load(self._logcache)
logs_instance.logger.debug(f"Memory Log {self._log._name}: read cache: {self._logcache}")
except Exception:
try:
self._cache_write(logs_instance.logger, self._cachefile, self._log.export(int(self._maxlen)))
self._cache_read(self._cachefile, self._shtime.tzinfo())
logs_instance.logger.info(f"Memory Log {self._log._name}: generated cache file")
except Exception as e:
pass
logs_instance.logger.warning(f"Memory Log: problem reading cache: {e}")
[Doku] def emit(self, record):
#logs_instance.logger.info(f"ShngMemLogHandler.emit() #1: logname={self._log._name}, handlername={self.get_name()}, level={self.level}, record.levelno={record.levelno}, record.levelname={record.levelname}, record={record}")
#logs_instance.logger.info(f"ShngMemLogHandler.emit() #2: self={self}, handlers={logging._handlers.data}")
try:
self.format(record)
timestamp = datetime.datetime.fromtimestamp(record.created, self._shtime.tzinfo())
self._log.add([timestamp, record.threadName, record.levelname, record.message])
except Exception:
self.handleError(record)
if self._cache is True:
try:
self._cache_write(logs_instance.logger, self._cachefile, self._log.export(int(self._maxlen)))
except Exception as e:
logs_instance.logger.warning(f"Memory Log {self._log._name}: could not update cache {e}")
##############################################################################################
# Cache Methods, taken from operationlog plugin by Jan Troelsen, Oliver Hinckel, Bernd Meiners
##############################################################################################
[Doku] def load(self, logentries):
"""
Loads logentries (which were just read from cache) into the log object (see lib.log.Log())
"""
if len(logentries) != 0:
for logentry in reversed(logentries):
log = []
for name in self._log.mapping:
if name == 'time':
log.append(logentry['time'])
elif name == 'thread':
log.append(logentry['thread'])
elif name == 'level':
log.append(logentry['level'])
elif name == 'message':
log.append(logentry['message'])
self._log.add(log)
def _cache_read(self, filename, tz):
"""
This loads the cache from a file
:param filename: file to load from
:param tz: timezone
:return: [description]
:rtype: a tuple with datetime and values from file
"""
ts = os.path.getmtime(filename)
dt = datetime.datetime.fromtimestamp(ts, tz)
value = None
with open(filename, 'rb') as f:
value = pickle.load(f)
return (dt, value)
def _cache_write(self, logger, filename, value):
try:
with open(filename, 'wb') as f:
pickle.dump(value, f)
except IOError:
logger.warning("Could not write to {}".format(filename))