move file based properties out of core

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>
This commit is contained in:
Steven Armstrong 2011-10-10 14:54:26 +02:00
parent 44a722042a
commit f3932bb662

214
lib/cdist/util/property.py Normal file
View file

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# -*- coding: utf-8 -*-
#
# 2010-2011 Steven Armstrong (steven-cdist at armstrong.cc)
#
# This file is part of cdist.
#
# cdist 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.
#
# cdist 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 cdist. If not, see <http://www.gnu.org/licenses/>.
#
#
import os
import collections
import cdist
class AbsolutePathRequiredError(cdist.Error):
def __init__(self, path):
self.path = path
def __str__(self):
return 'Absolute path required, got: %s' % self.path
class FileList(collections.MutableSequence):
"""A list that stores it's state in a file.
"""
def __init__(self, path, initial=None):
if not os.path.isabs(path):
raise AbsolutePathRequiredError(path)
self._path = path
if initial:
# delete existing file
os.unlink(self._path)
for i in initial:
self.append(i)
def __read(self):
lines = []
try:
with open(self._path) as fd:
for line in fd:
lines.append(line.rstrip('\n'))
except EnvironmentError as e:
# error ignored
pass
return lines
def __write(self, lines):
try:
with open(self._path, 'w') as fd:
for line in lines:
fd.write(str(line) + '\n')
except EnvironmentError as e:
# error ignored
raise
def __repr__(self):
return repr(list(self))
def __getitem__(self, index):
return self.__read()[index]
def __setitem__(self, index, value):
lines = self.__read()
lines[index] = value
self.__write(lines)
def __delitem__(self, index):
lines = self.__read()
del lines[index]
self.__write(lines)
def __len__(self):
lines = self.__read()
return len(lines)
def insert(self, index, value):
lines = self.__read()
lines.insert(index, value)
self.__write(lines)
def sort(self):
lines = sorted(self)
self.__write(lines)
class FileListProperty(FileList):
# Descriptor Protocol
def __get__(self, obj, objtype=None):
if obj is None:
return self.__class__
return self
def __set__(self, obj, value):
os.unlink(self._path)
for item in value:
self.append(item)
def __delete__(self, obj):
raise AttributeError("can't delete attribute")
class DirectoryDict(collections.MutableMapping):
"""A dict that stores it's state in a directory.
"""
def __init__(self, path, dict=None, **kwargs):
if not os.path.isabs(path):
raise AbsolutePathRequiredError(path)
self._path = path
if dict is not None:
self.update(dict)
if len(kwargs):
self.update(kwargs)
def __repr__(self):
return repr(dict(self))
def __getitem__(self, key):
try:
with open(os.path.join(self._path, key), "r") as fd:
return fd.read().rstrip('\n')
except EnvironmentError:
raise KeyError(key)
def __setitem__(self, key, value):
with open(os.path.join(self._path, key), "w") as fd:
fd.write(str(value))
def __delitem__(self, key):
os.remove(os.path.join(self._path, key))
def __iter__(self):
return iter(os.listdir(self._path))
def __len__(self):
return len(os.listdir(self._path))
class DirectoryDictProperty(DirectoryDict):
# Descriptor Protocol
def __get__(self, obj, objtype=None):
if obj is None:
return self.__class__
return self
def __set__(self, obj, value):
for name in self.keys():
del self[name]
if value is not None:
self.update(value)
def __delete__(self, obj):
raise AttributeError("can't delete attribute")
class FileBooleanProperty(object):
def __init__(self, path):
"""
:param path: string or callable
Usage:
class Foo(object):
changed = FileBoolean(lambda obj: os.path.join(obj.absolute_path, 'changed'))
other_boolean = FileBoolean('/tmp/other_boolean')
def __init__(self):
self.absolute_path = '/tmp/foo_boolean'
"""
self._path = path
def _get_path(self, *args, **kwargs):
path = self._path
if callable(path):
return path(*args, **kwargs)
if not os.path.isabs(path):
raise AbsolutePathRequiredError(path)
return path
# Descriptor Protocol
def __get__(self, obj, objtype=None):
if obj is None:
return self.__class__
path = self._get_path(obj)
return os.path.isfile(path)
def __set__(self, obj, value):
path = self._get_path(obj)
if value:
open(path, "w").close()
else:
try:
os.remove(path)
except EnvironmentError:
# ignore
pass
def __delete__(self, obj):
raise AttributeError("can't delete attribute")