Files
deb-python-requestbuilder/requestbuilder/mixins.py
2015-04-22 13:59:21 -07:00

241 lines
9.6 KiB
Python

# Copyright (c) 2012-2014, Eucalyptus Systems, Inc.
#
# Permission to use, copy, modify, and/or distribute this software for
# any purpose with or without fee is hereby granted, provided that the
# above copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
import argparse
import math
import os
import signal
import sys
try:
import progressbar
except ImportError:
pass
from requestbuilder import Arg, MutuallyExclusiveArgList
class RegionConfigurableMixin(object):
"""
A mixin that allows the user to specify which user/region names to use
for the configuration via a --region arg and, if a 'REGION_ENVVAR' class
variable is set, an environment variable as well. The included
update_config_view method actually reads these data and updates
self.config to point to them.
"""
ARGS = [Arg('--region', metavar='USER@REGION', route_to=None,
help=('region and/or user names to search when looking up '
'config file data'))]
def update_config_view(self, region=None, user=None):
# Different sources of user/region info can override only parts of
# the set, so we only overwite things conditionally.
# self.args gets highest precedence
if self.args.get('region'):
_user, _region = self.__parse_region(self.args['region'])
user = user or _user
region = region or _region
# Environment comes next
if (getattr(self, 'REGION_ENVVAR', None) and
os.getenv(self.REGION_ENVVAR)):
_user, _region = self.__parse_region(os.getenv(self.REGION_ENVVAR))
user = user or _user
region = region or _region
# Default region from the config file
if not region:
region = self.config.get_global_option('default-region')
# User info can come from a region, so set that in the config now.
if region:
self.config.region = region
# Look up the region's user if needed...
if not user:
user = self.config.get_region_option('user')
# ...and finally update the config with that as well.
if user:
self.config.user = user
@staticmethod
def __parse_region(regionish):
"""
Given a string with pattern "[USER@][REGION]", return the user
and region names that that string represents, if any, and None
for the values it does not represent.
Examples:
- "" -> (None, None)
- "spam" -> (None, "spam")
- "eggs@" -> ("eggs", None)
- "eggs@spam" -> ("eggs", "spam")
"""
if not regionish:
return None, None
if regionish.endswith('@'):
return regionish.rstrip('@'), None
elif '@' in regionish:
return regionish.split('@', 1)
else:
return None, regionish
class TabifyingMixin(object):
'''
A command mixin that provides the tabify() function along with its
associated --show-empty-fields command line arg.
'''
ARGS = [Arg('--show-empty-fields', action='store_true', route_to=None,
help='show empty values as "(nil)"')]
def tabify(self, fields, include=None):
'''
Join a list of strings with tabs. Nonzero items that Python considers
false are printed as-is if they appear in the include list, replaced
with '(nil)' if the user specifies --show-empty-fields at the command
line, and omitted otherwise.
'''
def allowable(item):
return bool(item) or item is 0 or item in (include or [])
if self.args['show_empty_fields']:
fstr = '(nil)'
else:
fstr = ''
return '\t'.join([str(f) if allowable(f) else fstr for f in fields])
if 'progressbar' in sys.modules:
_PROGRESS_BAR_COMMAND_ARGS = [
MutuallyExclusiveArgList(
Arg('--progress', dest='show_progress', action='store_true',
default=sys.stdout.isatty(), route_to=None,
help='show progress (the default when run interactively)'),
Arg('--no-progress', dest='show_progress', action='store_false',
default=sys.stdout.isatty(), route_to=None, help='''do not
show progress (the default when run non-interactively)'''))]
else:
# Keep them around so scripts don't break, but make them non-functional
#
# This isn't in a MutuallyExclusiveArgList because of an argparse bug:
# http://bugs.python.org/issue17890
_PROGRESS_BAR_COMMAND_ARGS = [
Arg('--progress', dest='show_progress', action='store_false',
default=False, route_to=None, help=argparse.SUPPRESS),
Arg('--no-progress', dest='show_progress', action='store_false',
default=False, route_to=None, help=argparse.SUPPRESS)]
class FileTransferProgressBarMixin(object):
'''
A command mixin that provides download/upload progress bar support,
along with options to enable or disable them. If progress bars are
disabled at the command line get_progressbar will return None. If the
progressbar module is unavailable get_progressbar will return None *and*
no progress-related options will be added.
'''
ARGS = _PROGRESS_BAR_COMMAND_ARGS
def get_progressbar(self, label=None, maxval=None):
if 'progressbar' in sys.modules and self.args.get('show_progress',
False):
widgets = []
if label is not None:
widgets += [label, ' ']
if maxval is not None:
widgets += [progressbar.Percentage(), ' ',
progressbar.Bar(marker='='), ' ',
_FileSize(), ' ',
progressbar.FileTransferSpeed(), ' ']
if 'AdaptiveETA' in dir(progressbar):
widgets.append(progressbar.AdaptiveETA())
else:
widgets.append(progressbar.ETA())
pbar = progressbar.ProgressBar(widgets=widgets,
maxval=(maxval or sys.maxint),
poll=0.05)
#
# The ProgressBar class initializer installs a signal handler
# for SIGWINCH to resize the progress bar. Sometimes this can
# interrupt long running system calls which can cause an
# IOError exception to be raised. The call to siginterrupt
# below will retrieve the currently installed signal handler
# for SIGWINCH and set the SA_RESTART flag. This will cause
# system calls to be restarted after the handler has been
# executed instead of raising an exception.
#
signal.siginterrupt(signal.SIGWINCH, False)
return pbar
else:
widgets += [_IndeterminateBouncingBar(marker='='), ' ',
_FileSize(), ' ',
progressbar.FileTransferSpeed(), ' ',
progressbar.Timer(format='Time: %s')]
pbar = _IndeterminateProgressBar(widgets=widgets,
maxval=(maxval or sys.maxint),
poll=0.05)
# See comment above
signal.siginterrupt(signal.SIGWINCH, False)
return pbar
else:
return _EveryMethodObject()
# Used as a placeholder for ProgressBar when progressbar isn't there
class _EveryMethodObject(object):
def do_nothing(self, *args, **kwargs):
pass
def __getattribute__(self, name):
return object.__getattribute__(self, 'do_nothing')
if 'progressbar' in sys.modules:
class _IndeterminateProgressBar(progressbar.ProgressBar):
def finish(self):
self.maxval = self.currval
progressbar.ProgressBar.finish(self)
class _IndeterminateBouncingBar(progressbar.BouncingBar):
'''
A BouncingBar that moves exactly one space each time it updates,
rather than one space per unit. This is mainly used for downloads with
unknown lengths.
'''
def __init__(self, *args, **kwargs):
progressbar.BouncingBar.__init__(self, *args, **kwargs)
self.__update_count = 0
def update(self, pbar, width):
orig_currval = pbar.currval
pbar.currval = self.__update_count
retval = progressbar.BouncingBar.update(self, pbar, width)
pbar.currval = orig_currval
self.__update_count += 1
return retval
class _FileSize(progressbar.Widget):
PREFIXES = ' kMGTPEZY'
def update(self, pbar):
if pbar.currval == 0:
power = 0
scaledval = 0
else:
power = int(math.log(pbar.currval, 1024))
scaledval = pbar.currval / 1024.0 ** power
return '{0:6.2f} {1}B'.format(scaledval, self.PREFIXES[power])