# -*- coding: utf-8 -*-
"""
.. versionadded:: 1.0.0
.. deprecated:: 1.2.0
Defines a number of log level attributes and :class:`LegacySyslogger` to
carry out the real work.
This module should not be used for new work, but is provided to smooth
the transition from *tclutils.log*.
By default, log entries are sent to standard output and the system logger.
Four valid log level constants are provided at the module level:
* **ERROR** -- a problem that means execution cannot, or should not continue
* **WARNING** -- an unexpected situtation but execution will continue
* **INFO** -- informational output not indicative of a problem e.g. progress
messages
* **DEBUG** -- a message that should only be emitted when debugging code
These constants may be used anywhere that a *level* is expected by
:class:`LegacySyslogger`.
"""
# Copyright © 2015 Tiger Computing Ltd
# This file is part of pytiger and distributed under the terms
# of a BSD-like license
# See the file COPYING for details
from __future__ import absolute_import
import six
import sys
import syslog
import warnings
# Log levels
ERROR = 0
WARNING = 1
INFO = 2
DEBUG = 3
LOGLEVELS = (ERROR, WARNING, INFO, DEBUG)
LOGPREFIX = {
ERROR: 'E',
WARNING: 'W',
INFO: 'I',
DEBUG: 'D',
}
[docs]class LegacySyslogger(object):
"""
An object that looks a bit like a Python logging object
so that we can transition more easily later.
.. deprecated:: 1.2.0
Example usage:
>>> s = LegacySyslogger()
>>> # Long hand:
>>> s.log(WARNING, 'Unable to biggle')
W: Unable to biggle
>>> # Short hand:
>>> s.warning('Could not frob; continuing')
W: Could not frob, continuing
>>> s.error('Abandon ship, all ye who run this')
E: Abandon ship, all ye who run this
"""
def __init__(self):
warnings.warn('LegacySyslogger is deprecated', DeprecationWarning)
# minimum log level to send
self._log_level = DEBUG
# log to stdout?
self._log_to_stdout = True,
# log to syslog?
self._log_to_syslog = True,
# log tag
self._syslog_name = None
def __log_level_get(self):
"""
Minimum level at which to emit a log entry
"""
return self._log_level
def __log_level_set(self, value):
if value in LOGLEVELS:
self._log_level = value
else:
raise ValueError('%s not an acceptable log level' % value)
log_level = property(fget=__log_level_get, fset=__log_level_set,
doc="Minimum level at which to emit a log entry")
def __log_to_stdout_get(self):
"""
Whether to log to *stdout* (*True* or *False*)
"""
return self._log_to_stdout
def __log_to_stdout_set(self, value):
if value in (True, False):
self._log_to_stdout = value
else:
raise ValueError('log_to_stdout must be True or False')
log_to_stdout = property(fget=__log_to_stdout_get,
fset=__log_to_stdout_set,
doc="Whether to log to *stdout* (*True* or "
"*False*)")
def __log_to_syslog_get(self):
"""
Whether to log to *syslog* (*True* or *False*)
"""
return self._log_to_syslog
def __log_to_syslog_set(self, value):
if value in (True, False):
self._log_to_syslog = value
else:
raise ValueError('log_to_stdout must be True or False')
log_to_syslog = property(fget=__log_to_syslog_get,
fset=__log_to_syslog_set,
doc="Whether to log to *syslog* (*True* or "
"*False*)")
def __syslog_name_get(self):
"""
Log tag used in syslog messages (string)
"""
return self._syslog_name
def __syslog_name_set(self, value):
if isinstance(value, six.string_types):
self._syslog_name = value
else:
raise ValueError('syslog_name must be a string')
syslog_name = property(fget=__syslog_name_get, fset=__syslog_name_set,
doc="Log tag used in syslog messages (string)")
def _prefix_message(self, level, msg):
if level in LOGPREFIX:
return LOGPREFIX[level] + ": " + msg
else:
return msg
[docs] def log(self, level, msg):
"""
Print a message if its level is equal or less than
the filter level. Depending on configuration, the message
may be emitted to *syslog* or to *stdout* or both.
:param int level: Log message level
:param str msg: Log message text
"""
if level <= self.log_level:
# Add prefix to message
msg = self._prefix_message(level, msg)
if self.log_to_stdout:
sys.stderr.write(msg + "\n")
if self.log_to_syslog:
if self.syslog_name:
syslog.syslog("%s: %s" % (self.syslog_name, msg))
else:
syslog.syslog("%s" % (msg))
[docs] def debug(self, msg):
"""Shorthand for :func:`log(DEBUG, msg)`"""
self.log(DEBUG, msg)
[docs] def info(self, msg):
"""Shorthand for *log(INFO, msg)*"""
self.log(INFO, msg)
[docs] def warning(self, msg):
"""Shorthand for *log(WARNING, msg)*"""
self.log(WARNING, msg)
[docs] def error(self, msg):
"""Shorthand for *log(ERROR, msg)*"""
self.log(ERROR, msg)