Source code for pywbem._valuemapping

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"""
The :class:`~pywbem.ValueMapping` class supports translating between the values
of an integer-typed CIM element (e.g. property, method, or parameter) that is
qualified with the `ValueMap` and `Values` qualifiers, and the corresponding
values of the `Values` qualifier, in both directions.

This class supports value ranges (e.g. ``"4..6"``) and the unclaimed marker
(``".."``).
"""

import re
try:
    from collections import OrderedDict
except ImportError:
    from ordereddict import OrderedDict
import six

from ._cim_types import CIMInt, type_from_name
from ._cim_obj import CIMProperty, CIMMethod, CIMParameter
from ._utils import _format, _integerValue_to_int
from ._exceptions import ModelError

__all__ = ['ValueMapping']


[docs]class ValueMapping(object): """ *New in pywbem 0.9 as experimental and finalized in 0.10.* A utility class that supports translating between the values of an integer-typed CIM element (property, method, parameter) that is qualified with the `ValueMap` and `Values` qualifiers, and the corresponding values of the `Values` qualifier, in both directions. The CIM element may be a scalar or an array. This is done by retrieving the CIM class definition defining the CIM element in question, and by inspecting its `ValueMap` and `Values` qualifiers. The translation is performed by the :meth:`~pywbem.ValueMapping.tovalues` and :meth:`~pywbem.ValueMapping.tobinary` methods. Instances of this class must be created through one of the factory class methods: :meth:`~pywbem.ValueMapping.for_property`, :meth:`~pywbem.ValueMapping.for_method`, or :meth:`~pywbem.ValueMapping.for_parameter`. Value ranges (``"2..4"``) and the indicator for unclaimed values (``".."``) in the `ValueMap` qualifier are supported. All representations of the integer values in the `ValueMap` qualifier are supported (decimal, binary, octal, hexadecimal), consistent with the definition of the `ValueMap` qualifier in :term:`DSP0004`. Example: Given the following definition of a property in MOF: .. code-block:: text class CIM_Foo { [ValueMap{ "0", "2..4", "..6", "7..", "9", ".." }, Values{ "zero", "two-four", "five-six", "seven-eight", "nine", "unclaimed"}] uint16 MyProp; }; Assuming this class exists in a WBEM server, the following code will get the class from the server, create a value mapping for this property, and look up the `Values` strings that correspond to binary property values. This is useful when preparing binary property values for human consumption:: namespace = 'root/cimv2' conn = pywbem.WBEMConnection(...) # WBEM server myprop_vm = pywbem.ValueMapping.for_property( conn, namespace, 'CIM_Foo', 'MyProp') print("Binary value: Values string") for bin_value in range(0, 12): values_str = myprop_vm.tovalues(bin_value) print("{0:12}: {1!r}".format(bin_value, values_str)) Resulting output: .. code-block:: text Binary value: Values string 0: 'zero' 1: 'unclaimed' 2: 'two-four' 3: 'two-four' 4: 'two-four' 5: 'five-six' 6: 'five-six' 7: 'seven-eight' 8: 'seven-eight' 9: 'nine' 10: 'unclaimed' 11: 'unclaimed' Translating in the other direction is also of interest, for example when processing values that are provided by humans in terms of the `Values` strings, or when using the pywbem mock support and the test cases specify property values for CIM instances in terms of the more human-readable `Values` strings. Again, assuming the class shown above exists in a WBEM server, the following code will get the class from the server, create a value mapping for this property, and look up the binary property values from the `Values` strings:: namespace = 'root/cimv2' conn = pywbem.WBEMConnection(...) # WBEM server myprop_vm = pywbem.ValueMapping.for_property( conn, namespace, 'CIM_Foo', 'MyProp') values_strs = ["zero", "two-four", "five-six", "seven-eight", "nine", "unclaimed"] print("Values string: Binary value") for values_str in values_strs: bin_value = myprop_vm.tobinary(values_str) print("{0:12}: {1!r}".format(values_str, bin_value)) Resulting output: .. code-block:: text Values string: Binary value 'zero': 0 'two-four': (2, 4) 'five-six': (5, 6) 'seven-eight': (7, 8) 'nine': 9 'unclaimed': None Iterating through the pairs of `ValueMap` and `Values` entries is also possible. Assuming the class shown above exists in a WBEM server, the following code will get the class from the server, and iterate through the value mapping:: namespace = 'root/cimv2' conn = pywbem.WBEMConnection(...) # WBEM server myprop_vm = pywbem.ValueMapping.for_property( conn, namespace, 'CIM_Foo', 'MyProp') print("Values string: Binary value") for bin_value, values_str in myprop_vm.items(): print("{0:12}: {1!r}".format(values_str, bin_value)) Resulting output: .. code-block:: text Values string: Binary value 'zero': 0 'two-four': (2, 4) 'five-six': (5, 6) 'seven-eight': (7, 8) 'nine': 9 'unclaimed': None """ def __init__(self): self._conn = None self._namespace = None self._classname = None self._propname = None self._methodname = None self._parametername = None self._element_obj = None # Attributes for converting binary values to Values strings: self._b2v_single_dict = {} # for single values; bin: values self._b2v_range_tuple_list = [] # for value ranges; tuple(lo,hi,values) self._b2v_unclaimed = None # value of the unclaimed indicator '..' # Attributes for converting Values strings to binary values: self._v2b_dict = {} # values: bin (int or tuple)
[docs] @classmethod def for_property(cls, server, namespace, classname, propname): # pylint: disable=line-too-long """ Factory method that returns a new :class:`~pywbem.ValueMapping` instance that maps CIM property values to the `Values` qualifier defined on that property. The CIM property may be a scalar or an array. If a `Values` qualifier is defined but no `ValueMap` qualifier, a default of 0-based consecutive numbers is applied (that is the default defined in :term:`DSP0004`). Parameters: server (:class:`~pywbem.WBEMConnection` or :class:`~pywbem.WBEMServer`): The connection to the WBEM server containing the namespace. namespace (:term:`string`): Name of the CIM namespace containing the class. If `None`, the default namespace of the connection will be used. classname (:term:`string`): Name of the CIM class exposing the property. The property can be defined in that class or inherited into that class. propname (:term:`string`): Name of the CIM property that defines the `Values` / `ValueMap` qualifiers. Returns: The new :class:`~pywbem.ValueMapping` instance. Raises: Exceptions raised by :class:`~pywbem.WBEMConnection`. KeyError: The CIM property does not exist in the CIM class. ModelError: The CIM property is not integer-typed. ValueError: No `Values` qualifier defined on the CIM property. ModelError: Invalid integer representation in `ValueMap` qualifier defined on the CIM property. """ # noqa: E501 conn = server try: get_class = conn.GetClass except AttributeError: conn = server.conn get_class = conn.GetClass class_obj = get_class(ClassName=classname, namespace=namespace, LocalOnly=False, IncludeQualifiers=True) try: property_obj = class_obj.properties[propname] except KeyError: raise KeyError( _format("Class {0!A} (in {1!A}) does not have a property " "{2!A}", classname, namespace, propname)) new_vm = cls._create_for_element(property_obj, conn, namespace, classname, propname=propname) return new_vm
[docs] @classmethod def for_method(cls, server, namespace, classname, methodname): # pylint: disable=line-too-long """ Factory method that returns a new :class:`~pywbem.ValueMapping` instance that maps CIM method return values to the `Values` qualifier of that method. If a `Values` qualifier is defined but no `ValueMap` qualifier, a default of 0-based consecutive numbers is applied (that is the default defined in :term:`DSP0004`). Parameters: server (:class:`~pywbem.WBEMConnection` or :class:`~pywbem.WBEMServer`): The connection to the WBEM server containing the namespace. namespace (:term:`string`): Name of the CIM namespace containing the class. classname (:term:`string`): Name of the CIM class exposing the method. The method can be defined in that class or inherited into that class. methodname (:term:`string`): Name of the CIM method that defines the `Values` / `ValueMap` qualifiers. Returns: The new :class:`~pywbem.ValueMapping` instance. Raises: Exceptions raised by :class:`~pywbem.WBEMConnection`. KeyError: The CIM method does not exist in the CIM class. ModelError: The CIM method is not integer-typed. ValueError: No `Values` qualifier defined on the CIM method. ModelError: Invalid integer representation in `ValueMap` qualifier defined on the CIM method. """ # noqa: E501 conn = server try: get_class = conn.GetClass except AttributeError: conn = server.conn get_class = conn.GetClass class_obj = get_class(ClassName=classname, namespace=namespace, LocalOnly=False, IncludeQualifiers=True) try: method_obj = class_obj.methods[methodname] except KeyError: raise KeyError( _format("Class {0!A} (in {1!A}) does not have a method {2!A}", classname, namespace, methodname)) new_vm = cls._create_for_element(method_obj, conn, namespace, classname, methodname=methodname) return new_vm
[docs] @classmethod def for_parameter(cls, server, namespace, classname, methodname, parametername): # pylint: disable=line-too-long """ Factory method that returns a new :class:`~pywbem.ValueMapping` instance that maps CIM parameter values to the `Values` qualifier defined on that parameter. The CIM parameter may be a scalar or an array. If a `Values` qualifier is defined but no `ValueMap` qualifier, a default of 0-based consecutive numbers is applied (that is the default defined in :term:`DSP0004`). Parameters: server (:class:`~pywbem.WBEMConnection` or :class:`~pywbem.WBEMServer`): The connection to the WBEM server containing the namespace. namespace (:term:`string`): Name of the CIM namespace containing the class. classname (:term:`string`): Name of the CIM class exposing the method. The method can be defined in that class or inherited into that class. methodname (:term:`string`): Name of the CIM method that has the parameter. parametername (:term:`string`): Name of the CIM parameter that defines the `Values` / `ValueMap` qualifiers. Returns: The new :class:`~pywbem.ValueMapping` instance. Raises: Exceptions raised by :class:`~pywbem.WBEMConnection`. KeyError: The CIM method does not exist in the CIM class. KeyError: The CIM parameter does not exist in the CIM method. ModelError: The CIM parameter is not integer-typed. ValueError: No `Values` qualifier defined on the CIM parameter. ModelError: Invalid integer representation in `ValueMap` qualifier defined on the CIM parameter. """ # noqa: E501 conn = server try: get_class = conn.GetClass except AttributeError: conn = server.conn get_class = conn.GetClass class_obj = get_class(ClassName=classname, namespace=namespace, LocalOnly=False, IncludeQualifiers=True) try: method_obj = class_obj.methods[methodname] except KeyError: raise KeyError( _format("Class {0!A} (in {1!A}) does not have a method {2!A}", classname, namespace, methodname)) try: parameter_obj = method_obj.parameters[parametername] except KeyError: raise KeyError( _format("Method {0!A} in class {1!A} (in {2!A}) does not have " "a parameter {3!A}", methodname, classname, namespace, parametername)) new_vm = cls._create_for_element(parameter_obj, conn, namespace, classname, methodname=methodname, parametername=parametername) return new_vm
def _values_tuple(self, i, valuemap_list, values_list, cimtype): """ Return a tuple for the value range or unclaimed marker at position i, with these items: * lo - low value of the range * hi - high value of the range (can be equal to lo) * values - value of `Values` qualifier for this position Parameters: i (integer): position into valuemap_list and values_list valuemap_list (list of strings): `ValueMap` qualifier value values_list (list of strings): `Values` qualifier value cimtype (type): CIM type of the CIM element Raises: ModelError: Invalid integer representation in `ValueMap` qualifier defined on the CIM element. """ values_str = values_list[i] valuemap_str = valuemap_list[i] m = re.match(r'^(.*)\.\.(.*)$', valuemap_str) if m is None: valuemap_int = self._to_int(valuemap_str) return (valuemap_int, valuemap_int, values_str) # match found lo = m.group(1) if lo == '': if i == 0: lo = cimtype.minvalue else: _, previous_hi, _ = self._values_tuple( i - 1, valuemap_list, values_list, cimtype) lo = previous_hi + 1 else: lo = self._to_int(lo) hi = m.group(2) if hi == '': if i == len(valuemap_list) - 1: hi = cimtype.maxvalue else: next_lo, _, _ = self._values_tuple( i + 1, valuemap_list, values_list, cimtype) hi = next_lo - 1 else: hi = self._to_int(hi) return (lo, hi, values_str) def _to_int(self, val_str): """ Convert val_str to an integer or raise ModelError """ val = _integerValue_to_int(val_str) if val is None: raise ModelError( _format("The value-mapped {0} has an invalid integer " "representation in a ValueMap entry: {1!A}", self._element_str(), val_str)) return val @classmethod def _create_for_element(cls, element_obj, conn, namespace, classname, propname=None, methodname=None, parametername=None): # pylint: disable=line-too-long """ Return a new :class:`~pywbem.ValueMapping` instance for the specified CIM element. The CIM element may be a scalar or an array. If a `Values` qualifier is defined but no `ValueMap` qualifier, a default of 0-based consecutive numbers is applied (that is the default defined in :term:`DSP0004`). Parameters: element_obj (:class:`~pywbem.CIMProperty`, :class:`~pywbem.CIMMethod`, or :class:`~pywbem.CIMParameter`): The CIM element on which the qualifiers are defined. conn (:class:`~pywbem.WBEMConnection`): The connection to the WBEM server containing the namespace. namespace (:term:`string`): Name of the CIM namespace containing the class. classname (:term:`string`): Name of the CIM class exposing the property or method. The property or method can be defined in that class or inherited into that class. propname (:term:`string`): Name of the CIM property that defines the `Values` / `ValueMap` qualifiers. methodname (:term:`string`): Name of the CIM method that defines the `Values` / `ValueMap` qualifiers on its return value, or that has the parameter. parametername (:term:`string`): Name of the CIM parameter that defines the `Values` / `ValueMap` qualifiers. Returns: The created :class:`~pywbem.ValueMapping` instance for the specified CIM element. Raises: ModelError: The CIM element is not integer-typed. ValueError: No `Values` qualifier defined on the CIM element. ModelError: Invalid integer representation in `ValueMap` qualifier defined on the CIM element. """ # noqa: E501 # pylint: enable=line-too-long # pylint: disable=protected-access vm = ValueMapping() vm._element_obj = element_obj vm._conn = conn vm._namespace = namespace vm._classname = classname vm._propname = propname vm._methodname = methodname vm._parametername = parametername try: typename = element_obj.type # Property, Parameter except AttributeError: typename = element_obj.return_type # Method cimtype = type_from_name(typename) if not issubclass(cimtype, CIMInt): # This test works for both scalar and array-typed elements raise ModelError( _format("The value-mapped {0} is not integer-typed, but " "has CIM type: {1}", vm._element_str(), typename)) values_qual = element_obj.qualifiers.get('Values', None) if values_qual is None: # DSP0004 defines no default for a missing Values qualifier raise ValueError( _format("The value-mapped {0} has no Values qualifier " "defined", vm._element_str())) values_list = values_qual.value valuemap_qual = element_obj.qualifiers.get('ValueMap', None) if valuemap_qual is None: # DSP0004 defines a default of consecutive index numbers vm._b2v_single_dict = dict(zip(range(0, len(values_list)), values_list)) vm._b2v_range_tuple_list = [] vm._b2v_unclaimed = None vm._v2b_dict = OrderedDict(zip(values_list, range(0, len(values_list)))) else: vm._b2v_single_dict = {} vm._b2v_range_tuple_list = [] vm._b2v_unclaimed = None vm._v2b_dict = OrderedDict() valuemap_list = valuemap_qual.value for i, valuemap_str in enumerate(valuemap_list): values_str = values_list[i] if valuemap_str == '..': vm._b2v_unclaimed = values_str vm._v2b_dict[values_str] = None else: lo, hi, values_str = vm._values_tuple( i, valuemap_list, values_list, cimtype) if lo == hi: # single value vm._b2v_single_dict[lo] = values_str vm._v2b_dict[values_str] = lo else: # value range vm._b2v_range_tuple_list.append((lo, hi, values_str)) vm._v2b_dict[values_str] = (lo, hi) return vm def _element_str(self): """ Return a string that identifies the value-mapped element. """ # pylint: disable=no-else-return if isinstance(self.element, CIMProperty): return _format("property {0!A} in class {1!A} (in {2!A})", self.propname, self.classname, self.namespace) elif isinstance(self.element, CIMMethod): return _format("method {0!A} in class {1!A} (in {2!A})", self.methodname, self.classname, self.namespace) assert isinstance(self.element, CIMParameter) return _format("parameter {0!A} of method {1!A} in class {2!A} " "(in {3!A})", self.parametername, self.methodname, self.classname, self.namespace)
[docs] def __repr__(self): """ Return a representation of the :class:`~pywbem.ValueMapping` object with all attributes, that is suitable for debugging. """ return _format( "ValueMapping(" "_conn={s._conn!A}, " "_namespace={s._namespace!A}, " "_classname={s._classname!A}, " "_propname={s._propname!A}, " "_methodname={s._methodname!A}, " "_parametername={s._parametername!A}, " "_element_obj={s._element_obj!A}, " "_b2v_single_dict={s._b2v_single_dict!A}, " "_b2v_range_tuple_list={s._b2v_range_tuple_list!A}, " "_b2v_unclaimed={s._b2v_unclaimed!A}, " "_v2b_dict={s._v2b_dict!A})", s=self)
@property def conn(self): """ :class:`~pywbem.WBEMConnection`: Connection to the WBEM server containing the CIM namespace (that contains the mapped CIM element). """ return self._conn @property def namespace(self): """ :term:`string`: Name of the CIM namespace containing the class that defines the mapped CIM element. """ return self._namespace @property def classname(self): """ :term:`string`: Name of the CIM class defining the mapped CIM element. """ return self._classname @property def propname(self): """ :term:`string`: Name of the CIM property that is mapped. `None`, if no property is mapped. """ return self._propname @property def methodname(self): """ :term:`string`: Name of the CIM method, that either is mapped itself, or that has the parameter that is mapped. `None`, if no method or parameter is mapped. """ return self._methodname @property def parametername(self): """ :term:`string`: Name of the CIM parameter that is mapped. `None`, if no parameter is mapped. """ return self._parametername @property def element(self): # pylint: disable=line-too-long """ :class:`~pywbem.CIMProperty`, :class:`~pywbem.CIMMethod`, or :class:`~pywbem.CIMParameter`: The mapped CIM element. """ # noqa: E501 return self._element_obj
[docs] def tovalues(self, element_value): # pylint: disable=line-too-long """ Return the `Values` string(s) for an element value, based upon this value mapping. The element value may be a single value or list/tuple of values and the return value will be a single string or list of strings, respectively. An element value of `None` causes `None` to be returned. The passing of array values or scalar values does not need to match whether the element is array-typed or scalar-typed. For example, there may be a need to have the loop through a list of values of an array-typed element on the caller's side, invoking this method in the loop with a single value. As another example, the method may be used to translate a list of possible values for a scalar-typed element in one call to this method by passing them as a list. Parameters: element_value (:term:`integer` or :class:`~pywbem.CIMInt` or list/tuple thereof): The value(s) of the CIM element. May be `None`. Returns: :term:`string` or list of :term:`string`: The `Values` string(s) for the element value. This is: * a single string, if the element value was a single value * a list of strings, if the element value was a list/tuple of values * `None`, if the element value was `None` Raises: ValueError: Element value outside of the set defined by `ValueMap`. TypeError: Element value is not an integer type. """ # noqa: E501 if element_value is None: return None if isinstance(element_value, (list, tuple)): return [self._tovalues_single(ev) for ev in element_value] return self._tovalues_single(element_value)
def _tovalues_single(self, element_value): """ Return the `Values` string for a single element value, based upon this value mapping. Parameters: element_value (:term:`integer` or :class:`~pywbem.CIMInt`): The single integer value of the CIM element. Must not be `None`. Returns: :term:`string`: The single `Values` string for the element value. Raises: ValueError: Element value outside of the set defined by `ValueMap`. TypeError: Element value is not an integer type. """ if not isinstance(element_value, (six.integer_types, CIMInt)): raise TypeError( _format("The value for value-mapped {0} is not " "integer-typed, but has Python type: {1}", self._element_str(), type(element_value))) # try single value try: return self._b2v_single_dict[element_value] except KeyError: pass # try value ranges for range_tuple in self._b2v_range_tuple_list: lo, hi, values_str = range_tuple if lo <= element_value <= hi: return values_str # try catch-all '..' if self._b2v_unclaimed is not None: return self._b2v_unclaimed raise ValueError( _format("The value for value-mapped {0} is outside of the set " "defined by its ValueMap qualifier: {1!A}", self._element_str(), element_value))
[docs] def tobinary(self, values_str): """ Return the integer value or values for a `Values` string, based upon this value mapping. Due to the complexity of its return value, this method only supports a single `Values` string at a time. It does support array-typed elements, though. Thus, if multiple `Values` strings need to be translated, this method must be invoked once for each value to be translated. Any returned integer value is represented as the CIM type of the element (e.g. :class:`~pywbem.Uint16`). If the `Values` string corresponds to a single value, that single value is returned as an integer. If the `Values` string corresponds to a value range (e.g. "1.." or "..2" or "3..4"), that value range is returned as a tuple with two items that are the lowest and the highest value of the range. That is the case also when the value range is open on the left side or right side. If the `Values` string corresponds to the `unclaimed` indicator "..", `None` is returned. Parameters: values_str (:term:`string`): The `Values` string for the (single) element value. Must not be `None`. Returns: :class:`~pywbem.CIMInt` or tuple of :class:`~pywbem.CIMInt` or `None`: The element value or value range corresponding to the `Values` string, or `None` for unclaimed. Raises: ValueError: `Values` string outside of the set defined by `Values`. TypeError: `Values` string is not a string type. """ if not isinstance(values_str, six.string_types): raise TypeError( _format("The values string for value-mapped {0} is not " "string-typed, but has Python type: {1}", self._element_str(), type(values_str))) try: return self._v2b_dict[values_str] except KeyError: raise ValueError( _format("The values string for value-mapped {0} is outside " "of the set defined by its Values qualifier: {1!A}", self._element_str(), values_str))
[docs] def items(self): """ Generator that iterates through the items of the value mapping. The items are the array entries of the `Values` and `ValueMap` qualifiers, and they are iterated in the order specified in the arrays. If the `ValueMap` qualifier is not specified, the default of consecutive integers starting at 0 is used as a default, consistent with :term:`DSP0004`. Each iterated item is a tuple of integer value(s) representing the `ValueMap` array entry, and the corresponding `Values` string. Any integer value in the iterated items is represented as the CIM type of the element (e.g. :class:`~pywbem.Uint16`). If the `Values` string corresponds to a single element value, the first tuple item is that single integer value. If the `Values` string corresponds to a value range (e.g. "1.." or "..2" or "3..4"), that value range is returned as a tuple with two items that are the lowest and the highest value of the range. That is the case also when the value range is open on the left side or right side. If the `Values` string corresponds to the `unclaimed` indicator "..", the first tuple item is `None`. Returns: :term:`iterator` for tuple of integer value(s) and `Values` string. """ for values_str in self._v2b_dict: element_value = self._v2b_dict[values_str] yield element_value, values_str