ed0e145ea3
* Optimize _Backstore constructor to find a free index for the cache. Build a temporary set to check if an index is used or not. * Replace dict.iteritems() with six.iteritems(dict) * Replace dict.itervalues() with six.itervalues(dict) * Fix syntax of relative imports * Get range from six.moves to get xrange() on Python 2 and range() on Python 3 * Replace it.next() with next(it) * Stop using 2to3 in setup.py * Add Python 3 classifier to setup.py * Sort also imports
232 lines
8.1 KiB
Python
232 lines
8.1 KiB
Python
'''
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Implements the base CFSNode class and a few inherited variants.
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This file is part of RTSLib.
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Copyright (c) 2011-2013 by Datera, Inc
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Copyright (c) 2011-2014 by Red Hat, Inc.
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Licensed under the Apache License, Version 2.0 (the "License"); you may
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not use this file except in compliance with the License. You may obtain
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a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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License for the specific language governing permissions and limitations
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under the License.
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'''
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import os
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import stat
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from .utils import fread, fwrite, RTSLibError, RTSLibNotInCFS
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class CFSNode(object):
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# Where is the configfs base LIO directory ?
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configfs_dir = '/sys/kernel/config/target'
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# CFSNode private stuff
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def __init__(self):
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self._path = self.configfs_dir
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def __eq__(self, other):
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return self._path == other._path
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def __ne__(self, other):
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return self._path != other._path
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def _get_path(self):
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return self._path
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def _create_in_cfs_ine(self, mode):
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'''
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Creates the configFS node if it does not already exist, depending on
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the mode.
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any -> makes sure it exists, also works if the node already does exist
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lookup -> make sure it does NOT exist
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create -> create the node which must not exist beforehand
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'''
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if mode not in ['any', 'lookup', 'create']:
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raise RTSLibError("Invalid mode: %s" % mode)
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if self.exists and mode == 'create':
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raise RTSLibError("This %s already exists in configFS"
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% self.__class__.__name__)
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elif not self.exists and mode == 'lookup':
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raise RTSLibNotInCFS("No such %s in configfs: %s"
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% (self.__class__.__name__, self.path))
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if not self.exists:
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try:
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os.mkdir(self.path)
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except:
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raise RTSLibError("Could not create %s in configFS"
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% self.__class__.__name__)
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def _exists(self):
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return os.path.isdir(self.path)
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def _check_self(self):
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if not self.exists:
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raise RTSLibNotInCFS("This %s does not exist in configFS"
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% self.__class__.__name__)
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def _list_files(self, path, writable=None):
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'''
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List files under a path depending on their owner's write permissions.
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@param path: The path under which the files are expected to be. If the
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path itself is not a directory, an empty list will be returned.
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@type path: str
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@param writable: If None (default), returns all parameters, if True,
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returns read-write parameters, if False, returns just the read-only
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parameters.
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@type writable: bool or None
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@return: List of file names filtered according to their write perms.
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'''
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if not os.path.isdir(path):
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return []
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if writable is None:
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names = os.listdir(path)
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elif writable:
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names = [name for name in os.listdir(path)
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if (os.stat("%s/%s" % (path, name))[stat.ST_MODE] \
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& stat.S_IWUSR)]
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else:
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names = [os.path.basename(name) for name in os.listdir(path)
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if not (os.stat("%s/%s" % (path, name))[stat.ST_MODE] \
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& stat.S_IWUSR)]
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names.sort()
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return names
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# CFSNode public stuff
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def list_parameters(self, writable=None):
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'''
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@param writable: If None (default), returns all parameters, if True,
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returns read-write parameters, if False, returns just the read-only
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parameters.
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@type writable: bool or None
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@return: The list of existing RFC-3720 parameter names.
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'''
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self._check_self()
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path = "%s/param" % self.path
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return self._list_files(path, writable)
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def list_attributes(self, writable=None):
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'''
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@param writable: If None (default), returns all attributes, if True,
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returns read-write attributes, if False, returns just the read-only
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attributes.
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@type writable: bool or None
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@return: A list of existing attribute names as strings.
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'''
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self._check_self()
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path = "%s/attrib" % self.path
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return self._list_files(path, writable)
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def set_attribute(self, attribute, value):
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'''
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Sets the value of a named attribute.
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The attribute must exist in configFS.
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@param attribute: The attribute's name. It is case-sensitive.
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@type attribute: string
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@param value: The attribute's value.
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@type value: string
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'''
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self._check_self()
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path = "%s/attrib/%s" % (self.path, str(attribute))
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if not os.path.isfile(path):
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raise RTSLibError("Cannot find attribute: %s"
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% str(attribute))
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else:
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try:
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fwrite(path, "%s" % str(value))
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except Exception as e:
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raise RTSLibError("Cannot set attribute %s: %s" % (attribute, e))
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def get_attribute(self, attribute):
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'''
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@param attribute: The attribute's name. It is case-sensitive.
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@return: The named attribute's value, as a string.
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'''
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self._check_self()
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path = "%s/attrib/%s" % (self.path, str(attribute))
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if not os.path.isfile(path):
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raise RTSLibError("Cannot find attribute: %s" % attribute)
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else:
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return fread(path)
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def set_parameter(self, parameter, value):
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'''
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Sets the value of a named RFC-3720 parameter.
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The parameter must exist in configFS.
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@param parameter: The RFC-3720 parameter's name. It is case-sensitive.
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@type parameter: string
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@param value: The parameter's value.
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@type value: string
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'''
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self._check_self()
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path = "%s/param/%s" % (self.path, str(parameter))
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if not os.path.isfile(path):
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raise RTSLibError("Cannot find parameter: %s" % parameter)
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else:
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try:
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fwrite(path, "%s\n" % str(value))
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except Exception as e:
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raise RTSLibError("Cannot set parameter %s: %s" % (parameter, e))
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def get_parameter(self, parameter):
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'''
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@param parameter: The RFC-3720 parameter's name. It is case-sensitive.
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@type parameter: string
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@return: The named parameter value as a string.
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'''
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self._check_self()
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path = "%s/param/%s" % (self.path, str(parameter))
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if not os.path.isfile(path):
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raise RTSLibError("Cannot find RFC-3720 parameter: %s" % parameter)
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else:
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return fread(path)
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def delete(self):
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'''
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If the underlying configFS object does not exist, this method does
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nothing. If the underlying configFS object exists, this method attempts
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to delete it.
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'''
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if self.exists:
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os.rmdir(self.path)
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path = property(_get_path,
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doc="Get the configFS object path.")
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exists = property(_exists,
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doc="Is True as long as the underlying configFS object exists. " \
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+ "If the underlying configFS objects gets deleted " \
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+ "either by calling the delete() method, or by any " \
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+ "other means, it will be False.")
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def dump(self):
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d = {}
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attrs = {}
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params = {}
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for item in self.list_attributes(writable=True):
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attrs[item] = int(self.get_attribute(item))
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if attrs:
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d['attributes'] = attrs
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for item in self.list_parameters(writable=True):
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params[item] = self.get_parameter(item)
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if params:
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d['parameters'] = params
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return d
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def _test():
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import doctest
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doctest.testmod()
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if __name__ == "__main__":
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_test()
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