# -*- coding: utf-8 -*-
# spechomo, Spectral homogenization of multispectral satellite data
#
# Copyright (C) 2019-2021
# - Daniel Scheffler (GFZ Potsdam, daniel.scheffler@gfz-potsdam.de)
# - Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences Potsdam,
# Germany (https://www.gfz-potsdam.de/)
#
# This software was developed within the context of the GeoMultiSens project funded
# by the German Federal Ministry of Education and Research
# (project grant code: 01 IS 14 010 A-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
#
# Please note the following exception: `spechomo` depends on tqdm, which is
# distributed under the Mozilla Public Licence (MPL) v2.0 except for the files
# "tqdm/_tqdm.py", "setup.py", "README.rst", "MANIFEST.in" and ".gitignore".
# Details can be found here: https://github.com/tqdm/tqdm/blob/master/LICENCE.
#
# 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.
"""SpecHomo logging module containing logging related classes and functions."""
import logging
import os
import warnings
import sys
try:
# noinspection PyCompatibility
from StringIO import StringIO # Python 2
except ImportError:
from io import StringIO # Python 3
[docs]class SpecHomo_Logger(logging.Logger):
"""Class for the SpecHomo logger."""
def __init__(self, name_logfile, fmt_suffix=None, path_logfile=None, log_level='INFO', append=True):
# type: (str, any, str, any, bool) -> None
"""Return a logging.logger instance pointing to the given logfile path.
:param name_logfile:
:param fmt_suffix: if given, it will be included into log formatter
:param path_logfile: if no path is given, only a StreamHandler is created
:param log_level: the logging level to be used (choices: 'DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL';
default: 'INFO')
:param append: <bool> whether to append the log message to an existing logfile (1)
or to create a new logfile (0); default=1
"""
# private attributes
self._captured_stream = ''
# attributes that need to be present in order to unpickle the logger via __setstate_
self.name_logfile = name_logfile
self.fmt_suffix = fmt_suffix
self.path_logfile = path_logfile
self.log_level = log_level
super(SpecHomo_Logger, self).__init__(name_logfile)
self.path_logfile = path_logfile
self.formatter_fileH = logging.Formatter('%(asctime)s' + (' [%s]' % fmt_suffix if fmt_suffix else '') +
' %(levelname)s: %(message)s', datefmt='%Y/%m/%d %H:%M:%S')
self.formatter_ConsoleH = logging.Formatter('%(asctime)s' + (' [%s]' % fmt_suffix if fmt_suffix else '') +
': %(message)s', datefmt='%Y/%m/%d %H:%M:%S')
if path_logfile:
# create output directory
while not os.path.isdir(os.path.dirname(path_logfile)):
try:
os.makedirs(os.path.dirname(path_logfile))
except OSError as e:
if e.errno != 17:
raise
else:
pass
# create FileHandler
fileHandler = logging.FileHandler(path_logfile, mode='a' if append else 'w')
fileHandler.setFormatter(self.formatter_fileH)
fileHandler.setLevel(log_level)
else:
fileHandler = None
# create StreamHandler
self.streamObj = StringIO()
streamHandler = logging.StreamHandler(stream=self.streamObj)
streamHandler.setFormatter(self.formatter_fileH)
streamHandler.set_name('StringIO handler')
# create ConsoleHandler for logging levels DEGUG and INFO -> logging to sys.stdout
consoleHandler_out = logging.StreamHandler(stream=sys.stdout) # by default it would go to sys.stderr
consoleHandler_out.setFormatter(self.formatter_ConsoleH)
consoleHandler_out.set_name('console handler stdout')
consoleHandler_out.setLevel(log_level)
consoleHandler_out.addFilter(LessThanFilter(logging.WARNING))
# create ConsoleHandler for logging levels WARNING, ERROR, CRITICAL -> logging to sys.stderr
consoleHandler_err = logging.StreamHandler(stream=sys.stderr)
consoleHandler_err.setFormatter(self.formatter_ConsoleH)
consoleHandler_err.setLevel(logging.WARNING)
consoleHandler_err.set_name('console handler stderr')
self.setLevel(log_level)
if not self.handlers:
if fileHandler:
self.addHandler(fileHandler)
self.addHandler(streamHandler)
self.addHandler(consoleHandler_out)
self.addHandler(consoleHandler_err)
def __getstate__(self):
self.close()
return self.__dict__
def __setstate__(self, ObjDict):
"""Define how the attributes of SpecHomo_Logger are unpickled."""
self.__init__(ObjDict['name_logfile'], fmt_suffix=ObjDict['fmt_suffix'], path_logfile=ObjDict['path_logfile'],
log_level=ObjDict['log_level'], append=True)
ObjDict = self.__dict__
return ObjDict
@property
def captured_stream(self) -> str:
"""Return the already captured logging stream.
NOTE:
- set self.captured_stream:
self.captured_stream = 'any string'
"""
if not self._captured_stream:
self._captured_stream = self.streamObj.getvalue()
return self._captured_stream
@captured_stream.setter
def captured_stream(self, string: str):
assert isinstance(string, str), "'captured_stream' can only be set to a string. Got %s." % type(string)
self._captured_stream = string
[docs] def close(self):
"""Close all logging handlers."""
# update captured_stream and flush stream
self.captured_stream += self.streamObj.getvalue()
for handler in self.handlers[:]:
try:
if handler.get_name() == 'StringIO handler':
self.streamObj.flush()
self.removeHandler(handler) # if not called with '[:]' the StreamHandlers are left open
try:
handler.flush()
except ValueError:
# ValueError: I/O operation on closed file
pass
handler.close()
except PermissionError:
warnings.warn('Could not properly close logfile due to a PermissionError: %s' % sys.exc_info()[1])
if self.handlers[:]:
warnings.warn('Not all logging handlers could be closed. Remaining handlers: %s' % self.handlers[:])
[docs] def view_logfile(self):
"""View the log file written to disk."""
with open(self.path_logfile) as inF:
print(inF.read())
def __del__(self):
self.close()
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.close()
return True if exc_type is None else False
[docs]def close_logger(logger):
"""Close the handlers of the given logging.Logger instance.
:param logger: logging.Logger instance or subclass instance
"""
if logger and hasattr(logger, 'handlers'):
for handler in logger.handlers[:]: # if not called with '[:]' the StreamHandlers are left open
try:
logger.removeHandler(handler)
handler.flush()
handler.close()
except PermissionError:
warnings.warn('Could not properly close logfile due to a PermissionError: %s' % sys.exc_info()[1])
if logger.handlers[:]:
warnings.warn('Not all logging handlers could be closed. Remaining handlers: %s' % logger.handlers[:])
[docs]def shutdown_loggers():
"""Shutdown any currently active loggers."""
logging.shutdown()
[docs]class LessThanFilter(logging.Filter):
"""Filter class to filter log messages by a maximum log level.
Based on http://stackoverflow.com/questions/2302315/
how-can-info-and-debug-logging-message-be-sent-to-stdout-and-higher-level-messag
"""
def __init__(self, exclusive_maximum, name=""):
"""Get an instance of LessThanFilter.
:param exclusive_maximum: maximum log level, e.g., logger.WARNING
:param name:
"""
super(LessThanFilter, self).__init__(name)
self.max_level = exclusive_maximum
[docs] def filter(self, record):
"""Filter funtion.
NOTE: Returns True if logging level of the given record is below the maximum log level.
:param record:
:return: bool
"""
# non-zero return means we log this message
return True if record.levelno < self.max_level else False