# Copyright (C) 2013-2014 Red Hat, Inc. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
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# those of the authors and should not be interpreted as representing official
# policies, either expressed or implied, of the FreeBSD Project.
#
# Authors: Michal Minar <miminar@redhat.com>
#
"""
Various utilities for LMI Scripts.
"""
[docs]class FilteredDict(dict):
"""
Dictionary-like collection that wraps some other dictionary and provides
limited access to its keys and values. It permits to get, delete and set
items specified in advance.
.. note::
Please use only the methods overriden. This class does not guarantee
100% API compliance. Not overriden methods won't work properly.
:param list key_filter: Set of keys that can be get, set or deleted.
For other keys, :py:class:`KeyError` will be raised.
:param dictionary original: Original dictionary containing not only
keys in *key_filter* but others as well. All modifying operations
operate also on this dictionary. But only those keys in *key_filter*
can be affected by them.
"""
def __init__(self, key_filter, original=None):
dict.__init__(self)
if original is not None and not isinstance(original, dict):
raise TypeError("original needs to be a dictionary")
if original is None:
original = dict()
self._original = original
self._keys = frozenset(key_filter)
def __contains__(self, key):
return key in self._keys and key in self._original
def __delitem__(self, key):
if not key in self._keys:
raise KeyError(repr(key))
del self._original[key]
def clear(self):
for key in self._keys:
self._original.pop(key, None)
def copy(self):
return FilteredDict(self._keys, self._original)
def iterkeys(self):
for key in self._keys:
yield key
def __getitem__(self, key):
if not key in self._keys:
raise KeyError(repr(key))
return self._original[key]
def __iter__(self):
for key in self._keys:
if key in self._original:
yield key
def __eq__(self, other):
return ( isinstance(other, FilteredDict)
and self._original == other._original
and self._keys == other._keys)
def __lt__(self, other):
if isinstance(other, dict):
return dict((k, v) for k, v in self._original.items()
if k in self._keys) < other
if not isinstance(other, FilteredDict):
raise TypeError("Can not compare FilteredDict to objects"
" of other types!")
return self._original <= other._original and self._keys <= other._keys
def __len__(self):
return len(self.keys())
def __setitem__(self, key, value):
if not key in self._keys:
raise KeyError(repr(key))
self._original[key] = value
def keys(self):
return [k for k in self._keys if k in self._original]
def values(self):
return [self._original[k] for k in self.keys() if k in self._original]
def items(self):
return [(k, self._original[k]) for k in self.keys()]
def iteritems(self):
return iter(self.items())
def pop(self, key, *args):
ret = self[key]
del self[key]
return ret
def popitem(self):
for key in self._keys:
if key in self._original:
return self.pop(key)
raise KeyError("FilterDict is empty!")
def update(self, *args, **kwargs):
if len(args) > 1:
raise TypeError('Expected just one positional argument!')
if args and callable(getattr(args[0], 'keys', None)):
for key in args[0].keys():
self[key] = args[0][key]
elif args:
for key, value in args[0]:
self[key] = value
for key, value in kwargs.items():
self[key] = value