nova/nova/objects/fields.py

661 lines
20 KiB
Python

# Copyright 2013 Red Hat, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import abc
import datetime
import iso8601
import netaddr
from oslo.utils import timeutils
import six
from nova.i18n import _
from nova.network import model as network_model
class KeyTypeError(TypeError):
def __init__(self, expected, value):
super(KeyTypeError, self).__init__(
_('Key %(key)s must be of type %(expected)s not %(actual)s'
) % {'key': repr(value),
'expected': expected.__name__,
'actual': value.__class__.__name__,
})
class ElementTypeError(TypeError):
def __init__(self, expected, key, value):
super(ElementTypeError, self).__init__(
_('Element %(key)s:%(val)s must be of type %(expected)s'
' not %(actual)s'
) % {'key': key,
'val': repr(value),
'expected': expected,
'actual': value.__class__.__name__,
})
@six.add_metaclass(abc.ABCMeta)
class AbstractFieldType(object):
@abc.abstractmethod
def coerce(self, obj, attr, value):
"""This is called to coerce (if possible) a value on assignment.
This method should convert the value given into the designated type,
or throw an exception if this is not possible.
:param:obj: The NovaObject on which an attribute is being set
:param:attr: The name of the attribute being set
:param:value: The value being set
:returns: A properly-typed value
"""
pass
@abc.abstractmethod
def from_primitive(self, obj, attr, value):
"""This is called to deserialize a value.
This method should deserialize a value from the form given by
to_primitive() to the designated type.
:param:obj: The NovaObject on which the value is to be set
:param:attr: The name of the attribute which will hold the value
:param:value: The serialized form of the value
:returns: The natural form of the value
"""
pass
@abc.abstractmethod
def to_primitive(self, obj, attr, value):
"""This is called to serialize a value.
This method should serialize a value to the form expected by
from_primitive().
:param:obj: The NovaObject on which the value is set
:param:attr: The name of the attribute holding the value
:param:value: The natural form of the value
:returns: The serialized form of the value
"""
pass
@abc.abstractmethod
def describe(self):
"""Returns a string describing the type of the field."""
pass
@abc.abstractmethod
def stringify(self, value):
"""Returns a short stringified version of a value."""
pass
class FieldType(AbstractFieldType):
@staticmethod
def coerce(obj, attr, value):
return value
@staticmethod
def from_primitive(obj, attr, value):
return value
@staticmethod
def to_primitive(obj, attr, value):
return value
def describe(self):
return self.__class__.__name__
def stringify(self, value):
return str(value)
class UnspecifiedDefault(object):
pass
class Field(object):
def __init__(self, field_type, nullable=False,
default=UnspecifiedDefault, read_only=False):
self._type = field_type
self._nullable = nullable
self._default = default
self._read_only = read_only
def __repr__(self):
args = {
'nullable': self._nullable,
'default': self._default,
}
return '%s(%s)' % (self._type.__class__.__name__,
','.join(['%s=%s' % (k, v)
for k, v in args.items()]))
@property
def nullable(self):
return self._nullable
@property
def default(self):
return self._default
@property
def read_only(self):
return self._read_only
def _null(self, obj, attr):
if self.nullable:
return None
elif self._default != UnspecifiedDefault:
# NOTE(danms): We coerce the default value each time the field
# is set to None as our contract states that we'll let the type
# examine the object and attribute name at that time.
return self._type.coerce(obj, attr, self._default)
else:
raise ValueError(_("Field `%s' cannot be None") % attr)
def coerce(self, obj, attr, value):
"""Coerce a value to a suitable type.
This is called any time you set a value on an object, like:
foo.myint = 1
and is responsible for making sure that the value (1 here) is of
the proper type, or can be sanely converted.
This also handles the potentially nullable or defaultable
nature of the field and calls the coerce() method on a
FieldType to actually do the coercion.
:param:obj: The object being acted upon
:param:attr: The name of the attribute/field being set
:param:value: The value being set
:returns: The properly-typed value
"""
if value is None:
return self._null(obj, attr)
else:
return self._type.coerce(obj, attr, value)
def from_primitive(self, obj, attr, value):
"""Deserialize a value from primitive form.
This is responsible for deserializing a value from primitive
into regular form. It calls the from_primitive() method on a
FieldType to do the actual deserialization.
:param:obj: The object being acted upon
:param:attr: The name of the attribute/field being deserialized
:param:value: The value to be deserialized
:returns: The deserialized value
"""
if value is None:
return None
else:
return self._type.from_primitive(obj, attr, value)
def to_primitive(self, obj, attr, value):
"""Serialize a value to primitive form.
This is responsible for serializing a value to primitive
form. It calls to_primitive() on a FieldType to do the actual
serialization.
:param:obj: The object being acted upon
:param:attr: The name of the attribute/field being serialized
:param:value: The value to be serialized
:returns: The serialized value
"""
if value is None:
return None
else:
return self._type.to_primitive(obj, attr, value)
def describe(self):
"""Return a short string describing the type of this field."""
name = self._type.describe()
prefix = self.nullable and 'Nullable' or ''
return prefix + name
def stringify(self, value):
if value is None:
return 'None'
else:
return self._type.stringify(value)
class String(FieldType):
@staticmethod
def coerce(obj, attr, value):
# FIXME(danms): We should really try to avoid the need to do this
if isinstance(value, (six.string_types, int, long, float,
datetime.datetime)):
return unicode(value)
else:
raise ValueError(_('A string is required here, not %s') %
value.__class__.__name__)
@staticmethod
def stringify(value):
return '\'%s\'' % value
class UUID(FieldType):
@staticmethod
def coerce(obj, attr, value):
# FIXME(danms): We should actually verify the UUIDness here
return str(value)
class Integer(FieldType):
@staticmethod
def coerce(obj, attr, value):
return int(value)
class Float(FieldType):
def coerce(self, obj, attr, value):
return float(value)
class Boolean(FieldType):
@staticmethod
def coerce(obj, attr, value):
return bool(value)
class DateTime(FieldType):
@staticmethod
def coerce(obj, attr, value):
if isinstance(value, six.string_types):
# NOTE(danms): Being tolerant of isotime strings here will help us
# during our objects transition
value = timeutils.parse_isotime(value)
elif not isinstance(value, datetime.datetime):
raise ValueError(_('A datetime.datetime is required here'))
if value.utcoffset() is None:
# NOTE(danms): Legacy objects from sqlalchemy are stored in UTC,
# but are returned without a timezone attached.
# As a transitional aid, assume a tz-naive object is in UTC.
value = value.replace(tzinfo=iso8601.iso8601.Utc())
return value
def from_primitive(self, obj, attr, value):
return self.coerce(obj, attr, timeutils.parse_isotime(value))
@staticmethod
def to_primitive(obj, attr, value):
return timeutils.isotime(value)
@staticmethod
def stringify(value):
return timeutils.isotime(value)
class IPAddress(FieldType):
@staticmethod
def coerce(obj, attr, value):
try:
return netaddr.IPAddress(value)
except netaddr.AddrFormatError as e:
raise ValueError(six.text_type(e))
def from_primitive(self, obj, attr, value):
return self.coerce(obj, attr, value)
@staticmethod
def to_primitive(obj, attr, value):
return str(value)
class IPV4Address(IPAddress):
@staticmethod
def coerce(obj, attr, value):
result = IPAddress.coerce(obj, attr, value)
if result.version != 4:
raise ValueError(_('Network "%s" is not valid') % value)
return result
class IPV6Address(IPAddress):
@staticmethod
def coerce(obj, attr, value):
result = IPAddress.coerce(obj, attr, value)
if result.version != 6:
raise ValueError(_('Network "%s" is not valid') % value)
return result
class IPV4AndV6Address(IPAddress):
@staticmethod
def coerce(obj, attr, value):
result = IPAddress.coerce(obj, attr, value)
if result.version != 4 and result.version != 6:
raise ValueError(_('Network "%s" is not valid') % value)
return result
class IPNetwork(IPAddress):
@staticmethod
def coerce(obj, attr, value):
try:
return netaddr.IPNetwork(value)
except netaddr.AddrFormatError as e:
raise ValueError(six.text_type(e))
class IPV4Network(IPNetwork):
@staticmethod
def coerce(obj, attr, value):
try:
return netaddr.IPNetwork(value, version=4)
except netaddr.AddrFormatError as e:
raise ValueError(six.text_type(e))
class IPV6Network(IPNetwork):
@staticmethod
def coerce(obj, attr, value):
try:
return netaddr.IPNetwork(value, version=6)
except netaddr.AddrFormatError as e:
raise ValueError(six.text_type(e))
class CompoundFieldType(FieldType):
def __init__(self, element_type, **field_args):
self._element_type = Field(element_type, **field_args)
class List(CompoundFieldType):
def coerce(self, obj, attr, value):
if not isinstance(value, list):
raise ValueError(_('A list is required here'))
for index, element in enumerate(list(value)):
value[index] = self._element_type.coerce(
obj, '%s[%i]' % (attr, index), element)
return value
def to_primitive(self, obj, attr, value):
return [self._element_type.to_primitive(obj, attr, x) for x in value]
def from_primitive(self, obj, attr, value):
return [self._element_type.from_primitive(obj, attr, x) for x in value]
def stringify(self, value):
return '[%s]' % (
','.join([self._element_type.stringify(x) for x in value]))
class Dict(CompoundFieldType):
def coerce(self, obj, attr, value):
if not isinstance(value, dict):
raise ValueError(_('A dict is required here'))
for key, element in value.items():
if not isinstance(key, six.string_types):
# NOTE(guohliu) In order to keep compatibility with python3
# we need to use six.string_types rather than basestring here,
# since six.string_types is a tuple, so we need to pass the
# real type in.
raise KeyTypeError(six.string_types[0], key)
value[key] = self._element_type.coerce(
obj, '%s["%s"]' % (attr, key), element)
return value
def to_primitive(self, obj, attr, value):
primitive = {}
for key, element in value.items():
primitive[key] = self._element_type.to_primitive(
obj, '%s["%s"]' % (attr, key), element)
return primitive
def from_primitive(self, obj, attr, value):
concrete = {}
for key, element in value.items():
concrete[key] = self._element_type.from_primitive(
obj, '%s["%s"]' % (attr, key), element)
return concrete
def stringify(self, value):
return '{%s}' % (
','.join(['%s=%s' % (key, self._element_type.stringify(val))
for key, val in sorted(value.items())]))
class DictProxyField(object):
"""Descriptor allowing us to assign pinning data as a dict of key_types
This allows us to have an object field that will be a dict of key_type
keys, allowing that will convert back to string-keyed dict.
This will take care of the conversion while the dict field will make sure
that we store the raw json-serializable data on the object.
key_type should return a type that unambiguously responds to six.text_type
so that calling key_type on it yields the same thing.
"""
def __init__(self, dict_field_name, key_type=int):
self._fld_name = dict_field_name
self._key_type = key_type
def __get__(self, obj, obj_type=None):
if obj is None:
return self
if getattr(obj, self._fld_name) is None:
return
return {self._key_type(k): v
for k, v in six.iteritems(getattr(obj, self._fld_name))}
def __set__(self, obj, val):
if val is None:
setattr(obj, self._fld_name, val)
else:
setattr(obj, self._fld_name, {six.text_type(k): v
for k, v in six.iteritems(val)})
class Set(CompoundFieldType):
def coerce(self, obj, attr, value):
if not isinstance(value, set):
raise ValueError(_('A set is required here'))
coerced = set()
for element in value:
coerced.add(self._element_type.coerce(
obj, '%s["%s"]' % (attr, element), element))
return coerced
def to_primitive(self, obj, attr, value):
return tuple(
self._element_type.to_primitive(obj, attr, x) for x in value)
def from_primitive(self, obj, attr, value):
return set([self._element_type.from_primitive(obj, attr, x)
for x in value])
def stringify(self, value):
return 'set([%s])' % (
','.join([self._element_type.stringify(x) for x in value]))
class Object(FieldType):
def __init__(self, obj_name, **kwargs):
self._obj_name = obj_name
super(Object, self).__init__(**kwargs)
def coerce(self, obj, attr, value):
try:
obj_name = value.obj_name()
except AttributeError:
obj_name = ""
if obj_name != self._obj_name:
raise ValueError(_('An object of type %s is required here') %
self._obj_name)
return value
@staticmethod
def to_primitive(obj, attr, value):
return value.obj_to_primitive()
@staticmethod
def from_primitive(obj, attr, value):
# FIXME(danms): Avoid circular import from base.py
from nova.objects import base as obj_base
# NOTE (ndipanov): If they already got hydrated by the serializer, just
# pass them back unchanged
if isinstance(value, obj_base.NovaObject):
return value
return obj_base.NovaObject.obj_from_primitive(value, obj._context)
def describe(self):
return "Object<%s>" % self._obj_name
def stringify(self, value):
if 'uuid' in value.fields:
ident = '(%s)' % (value.obj_attr_is_set('uuid') and value.uuid or
'UNKNOWN')
elif 'id' in value.fields:
ident = '(%s)' % (value.obj_attr_is_set('id') and value.id or
'UNKNOWN')
else:
ident = ''
return '%s%s' % (self._obj_name, ident)
class NetworkModel(FieldType):
@staticmethod
def coerce(obj, attr, value):
if isinstance(value, network_model.NetworkInfo):
return value
elif isinstance(value, six.string_types):
# Hmm, do we need this?
return network_model.NetworkInfo.hydrate(value)
else:
raise ValueError(_('A NetworkModel is required here'))
@staticmethod
def to_primitive(obj, attr, value):
return value.json()
@staticmethod
def from_primitive(obj, attr, value):
return network_model.NetworkInfo.hydrate(value)
def stringify(self, value):
return 'NetworkModel(%s)' % (
','.join([str(vif['id']) for vif in value]))
class AutoTypedField(Field):
AUTO_TYPE = None
def __init__(self, **kwargs):
super(AutoTypedField, self).__init__(self.AUTO_TYPE, **kwargs)
class StringField(AutoTypedField):
AUTO_TYPE = String()
class UUIDField(AutoTypedField):
AUTO_TYPE = UUID()
class IntegerField(AutoTypedField):
AUTO_TYPE = Integer()
class FloatField(AutoTypedField):
AUTO_TYPE = Float()
class BooleanField(AutoTypedField):
AUTO_TYPE = Boolean()
class DateTimeField(AutoTypedField):
AUTO_TYPE = DateTime()
class IPAddressField(AutoTypedField):
AUTO_TYPE = IPAddress()
class IPV4AddressField(AutoTypedField):
AUTO_TYPE = IPV4Address()
class IPV6AddressField(AutoTypedField):
AUTO_TYPE = IPV6Address()
class IPV4AndV6AddressField(AutoTypedField):
AUTO_TYPE = IPV4AndV6Address()
class IPNetworkField(AutoTypedField):
AUTO_TYPE = IPNetwork()
class IPV4NetworkField(AutoTypedField):
AUTO_TYPE = IPV4Network()
class IPV6NetworkField(AutoTypedField):
AUTO_TYPE = IPV6Network()
class DictOfStringsField(AutoTypedField):
AUTO_TYPE = Dict(String())
class DictOfNullableStringsField(AutoTypedField):
AUTO_TYPE = Dict(String(), nullable=True)
class DictOfIntegersField(AutoTypedField):
AUTO_TYPE = Dict(Integer())
class ListOfStringsField(AutoTypedField):
AUTO_TYPE = List(String())
class SetOfIntegersField(AutoTypedField):
AUTO_TYPE = Set(Integer())
class ListOfSetsOfIntegersField(AutoTypedField):
AUTO_TYPE = List(Set(Integer()))
class ListOfDictOfNullableStringsField(AutoTypedField):
AUTO_TYPE = List(Dict(String(), nullable=True))
class ObjectField(AutoTypedField):
def __init__(self, objtype, **kwargs):
self.AUTO_TYPE = Object(objtype)
super(ObjectField, self).__init__(**kwargs)
class ListOfObjectsField(AutoTypedField):
def __init__(self, objtype, **kwargs):
self.AUTO_TYPE = List(Object(objtype))
super(ListOfObjectsField, self).__init__(**kwargs)