--- /dev/null
+#
+# NEPI, a framework to manage network experiments
+# Copyright (C) 2013 INRIA
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation;
+#
+# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
+#
+# Author: Alina Quereilhac <alina.quereilhac@inria.fr>
+
+### Attribute Types
+class Types:
+ """ Allowed types for the Attribute value
+ """
+ String = "STRING"
+ Bool = "BOOL"
+ Enumerate = "ENUM"
+ Double = "DOUBLE"
+ Integer = "INTEGER"
+
+### Attribute Flags
+class Flags:
+ """ Flags to characterize the scope of an Attribute
+ """
+ # Attribute value can not be read (it is hidden to the user)
+ NoRead = 1 # 1
+
+ # Attribute value can not be modified (it is not editable by the user)
+ NoWrite = 1 << 1 # 2
+
+ # Attribute value can be modified only before deployment
+ Design = 1 << 2 # 4
+
+ # Attribute value will be used at deployment time for initial configuration
+ Construct = 1 << 3 # 8
+
+ # Attribute provides credentials to access resources
+ Credential = 1 << 4 | Design # 16 + 4
+
+ # Attribute is a filter used to discover resources
+ Filter = 1 << 5 | Design # 32 + 4
+
+ # Attribute Flag is reserved for internal RM usage (i.e. should be
+ # transparent to the user)
+ Reserved = 1 << 6 # 64
+
+ # Attribute global is set to all resources of rtype
+ Global = 1 << 7 # 128
+
+
+class Attribute(object):
+ """ An Attribute exposes a configuration parameter of a resource
+ """
+
+ def __init__(self, name, help, type = Types.String,
+ flags = None, default = None, allowed = None,
+ range = None, set_hook = None):
+ """
+ :param name: Name of the Attribute
+ :type name: str
+
+ :param help: Description of the Attribute
+ :type help: str
+
+ :param type: The type expected for the Attribute value.
+ Should be one of Attribute.Types
+ :type type: str
+
+ :param flags: Defines Attribute behavior (i.e. whether it is read-only,
+ read and write, etc). This parameter must take its values from
+ Attribute.Flags. Flags values can be bitwised
+ :type flags: hex
+
+ :param default: Default value for the Attribute
+ :type default: Depends on the type of Attribute
+
+ :param allowed: List of values that the Attribute can take.
+ This parameter is only meaningful for Enumerate type Attributes
+ :type allowed: list
+
+ :param range: (max, min) tuple with range of possible values for
+ Attributes.
+ This parameter is only meaningful for Integer or Double type
+ Attributes
+ :type range: (int, int) or (float, float)
+
+ :param set_hook: Function that will be executed whenever a new
+ value is set for the Attribute.
+ :type set_hook: function
+
+ """
+ self._name = name
+ self._help = help
+ self._type = type
+ self._flags = flags or 0
+ self._allowed = allowed
+ self._range = range
+ self._default = self._value = default
+ # callback to be invoked upon changing the
+ # attribute value
+ self.set_hook = set_hook
+
+ @property
+ def name(self):
+ """ Returns the name of the Attribute """
+ return self._name
+
+ @property
+ def default(self):
+ """ Returns the default value of the Attribute """
+ return self._default
+
+ @property
+ def type(self):
+ """ Returns the type of the Attribute """
+ return self._type
+
+ @property
+ def help(self):
+ """ Returns the description of the Attribute """
+ return self._help
+
+ @property
+ def flags(self):
+ """ Returns the flags of the Attribute """
+ return self._flags
+
+ @property
+ def allowed(self):
+ """ Returns the set of allowed values for the Attribute """
+ return self._allowed
+
+ @property
+ def range(self):
+ """ Returns the range of allowed numerical values for the Attribute """
+ return self._range
+
+ def has_flag(self, flag):
+ """ Returns True if the Attribute has the flag 'flag'
+
+ :param flag: Flag to be checked
+ :type flag: Flags
+ """
+ return (self._flags & flag) == flag
+
+ def get_value(self):
+ """ Returns the value of the Attribute """
+ return self._value
+
+ def set_value(self, value):
+ """ Configure a new value for the Attribute """
+ valid = True
+
+ if self.type == Types.Enumerate:
+ valid = value in self._allowed
+
+ if self.type in [Types.Double, Types.Integer] and self.range:
+ (min, max) = self.range
+
+ value = float(value)
+
+ valid = (value >= min and value <= max)
+
+ valid = valid and self.is_valid_value(value)
+
+ if valid:
+ if self.set_hook:
+ # Hook receives old value, new value
+ value = self.set_hook(self._value, value)
+
+ self._value = value
+ else:
+ raise ValueError("Invalid value %s for attribute %s" %
+ (str(value), self.name))
+
+ value = property(get_value, set_value)
+
+ def is_valid_value(self, value):
+ """ Attribute subclasses will override this method to add
+ adequate validation"""
+ return True
+
+ @property
+ def has_changed(self):
+ """ Returns True if the value has changed from the default """
+ return self.value != self.default
+
git://git.onelab.eu / nepi.git / blobdiff