# Copyright 2013 IBM Corp. # # 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. """Common internal object model""" import abc import collections import copy import logging import warnings import oslo_messaging as messaging from oslo_utils import encodeutils from oslo_utils import excutils from oslo_utils import versionutils as vutils import six from oslo_versionedobjects._i18n import _, _LE from oslo_versionedobjects import exception from oslo_versionedobjects import fields as obj_fields LOG = logging.getLogger('object') class _NotSpecifiedSentinel(object): pass def _get_attrname(name): """Return the mangled name of the attribute's underlying storage.""" return '_obj_' + name def _make_class_properties(cls): # NOTE(danms/comstud): Inherit fields from super classes. # mro() returns the current class first and returns 'object' last, so # those can be skipped. Also be careful to not overwrite any fields # that already exist. And make sure each cls has its own copy of # fields and that it is not sharing the dict with a super class. cls.fields = dict(cls.fields) for supercls in cls.mro()[1:-1]: if not hasattr(supercls, 'fields'): continue for name, field in supercls.fields.items(): if name not in cls.fields: cls.fields[name] = field for name, field in six.iteritems(cls.fields): if not isinstance(field, obj_fields.Field): raise exception.ObjectFieldInvalid( field=name, objname=cls.obj_name()) def getter(self, name=name): attrname = _get_attrname(name) if not hasattr(self, attrname): self.obj_load_attr(name) return getattr(self, attrname) def setter(self, value, name=name, field=field): attrname = _get_attrname(name) field_value = field.coerce(self, name, value) if field.read_only and hasattr(self, attrname): # Note(yjiang5): _from_db_object() may iterate # every field and write, no exception in such situation. if getattr(self, attrname) != field_value: raise exception.ReadOnlyFieldError(field=name) else: return self._changed_fields.add(name) try: return setattr(self, attrname, field_value) except Exception: with excutils.save_and_reraise_exception(): attr = "%s.%s" % (self.obj_name(), name) LOG.exception(_LE('Error setting %(attr)s'), {'attr': attr}) def deleter(self, name=name): attrname = _get_attrname(name) if not hasattr(self, attrname): raise AttributeError("No such attribute `%s'" % name) delattr(self, attrname) setattr(cls, name, property(getter, setter, deleter)) class VersionedObjectRegistry(object): _registry = None def __new__(cls, *args, **kwargs): if not VersionedObjectRegistry._registry: VersionedObjectRegistry._registry = object.__new__( VersionedObjectRegistry, *args, **kwargs) VersionedObjectRegistry._registry._obj_classes = \ collections.defaultdict(list) self = object.__new__(cls, *args, **kwargs) self._obj_classes = VersionedObjectRegistry._registry._obj_classes return self def registration_hook(self, cls, index): pass def _register_class(self, cls): def _vers_tuple(obj): return vutils.convert_version_to_tuple(obj.VERSION) _make_class_properties(cls) obj_name = cls.obj_name() for i, obj in enumerate(self._obj_classes[obj_name]): self.registration_hook(cls, i) if cls.VERSION == obj.VERSION: self._obj_classes[obj_name][i] = cls break if _vers_tuple(cls) > _vers_tuple(obj): # Insert before. self._obj_classes[obj_name].insert(i, cls) break else: # Either this is the first time we've seen the object or it's # an older version than anything we'e seen. self._obj_classes[obj_name].append(cls) self.registration_hook(cls, 0) @classmethod def register(cls, obj_cls): registry = cls() registry._register_class(obj_cls) return obj_cls @classmethod def register_if(cls, condition): def wraps(obj_cls): if condition: registry = cls() registry._register_class(obj_cls) else: _make_class_properties(obj_cls) return obj_cls return wraps @classmethod def obj_classes(cls): registry = cls() return registry._obj_classes # These are decorators that mark an object's method as remotable. # If the metaclass is configured to forward object methods to an # indirection service, these will result in making an RPC call # instead of directly calling the implementation in the object. Instead, # the object implementation on the remote end will perform the # requested action and the result will be returned here. def remotable_classmethod(fn): """Decorator for remotable classmethods.""" @six.wraps(fn) def wrapper(cls, context, *args, **kwargs): if cls.indirection_api: version_manifest = obj_tree_get_versions(cls.obj_name()) try: result = cls.indirection_api.object_class_action_versions( context, cls.obj_name(), fn.__name__, version_manifest, args, kwargs) except NotImplementedError: # FIXME(danms): Maybe start to warn here about deprecation? result = cls.indirection_api.object_class_action( context, cls.obj_name(), fn.__name__, cls.VERSION, args, kwargs) else: result = fn(cls, context, *args, **kwargs) if isinstance(result, VersionedObject): result._context = context return result # NOTE(danms): Make this discoverable wrapper.remotable = True wrapper.original_fn = fn return classmethod(wrapper) # See comment above for remotable_classmethod() # # Note that this will use either the provided context, or the one # stashed in the object. If neither are present, the object is # "orphaned" and remotable methods cannot be called. def remotable(fn): """Decorator for remotable object methods.""" @six.wraps(fn) def wrapper(self, *args, **kwargs): ctxt = self._context if ctxt is None: raise exception.OrphanedObjectError(method=fn.__name__, objtype=self.obj_name()) if self.indirection_api: updates, result = self.indirection_api.object_action( ctxt, self, fn.__name__, args, kwargs) for key, value in six.iteritems(updates): if key in self.fields: field = self.fields[key] # NOTE(ndipanov): Since VersionedObjectSerializer will have # deserialized any object fields into objects already, # we do not try to deserialize them again here. if isinstance(value, VersionedObject): setattr(self, key, value) else: setattr(self, key, field.from_primitive(self, key, value)) self.obj_reset_changes() self._changed_fields = set(updates.get('obj_what_changed', [])) return result else: return fn(self, *args, **kwargs) wrapper.remotable = True wrapper.original_fn = fn return wrapper class VersionedObject(object): """Base class and object factory. This forms the base of all objects that can be remoted or instantiated via RPC. Simply defining a class that inherits from this base class will make it remotely instantiatable. Objects should implement the necessary "get" classmethod routines as well as "save" object methods as appropriate. """ indirection_api = None # Object versioning rules # # Each service has its set of objects, each with a version attached. When # a client attempts to call an object method, the server checks to see if # the version of that object matches (in a compatible way) its object # implementation. If so, cool, and if not, fail. # # This version is allowed to have three parts, X.Y.Z, where the .Z element # is reserved for stable branch backports. The .Z is ignored for the # purposes of triggering a backport, which means anything changed under # a .Z must be additive and non-destructive such that a node that knows # about X.Y can consider X.Y.Z equivalent. VERSION = '1.0' # Object namespace for serialization # NB: Generally this should not be changed, but is needed for backwards # compatibility OBJ_SERIAL_NAMESPACE = 'versioned_object' # Object project namespace for serialization # This is used to disambiguate owners of objects sharing a common RPC # medium OBJ_PROJECT_NAMESPACE = 'versionedobjects' # The fields present in this object as key:field pairs. For example: # # fields = { 'foo': obj_fields.IntegerField(), # 'bar': obj_fields.StringField(), # } fields = {} obj_extra_fields = [] # Table of sub-object versioning information # # This contains a list of version mappings, by the field name of # the subobject. The mappings must be in order of oldest to # newest, and are tuples of (my_version, subobject_version). A # request to backport this object to $my_version will cause the # subobject to be backported to $subobject_version. # # obj_relationships = { # 'subobject1': [('1.2', '1.1'), ('1.4', '1.2')], # 'subobject2': [('1.2', '1.0')], # } # # In the above example: # # - If we are asked to backport our object to version 1.3, # subobject1 will be backported to version 1.1, since it was # bumped to version 1.2 when our version was 1.4. # - If we are asked to backport our object to version 1.5, # no changes will be made to subobject1 or subobject2, since # they have not changed since version 1.4. # - If we are asked to backlevel our object to version 1.1, we # will remove both subobject1 and subobject2 from the primitive, # since they were not added until version 1.2. obj_relationships = {} def __init__(self, context=None, **kwargs): self._changed_fields = set() self._context = context for key in kwargs.keys(): setattr(self, key, kwargs[key]) def __repr__(self): repr_str = '%s(%s)' % ( self.obj_name(), ','.join(['%s=%s' % (name, (self.obj_attr_is_set(name) and field.stringify(getattr(self, name)) or '')) for name, field in sorted(self.fields.items())])) if not six.PY3: repr_str = encodeutils.safe_encode(repr_str, incoming='utf-8') return repr_str def __contains__(self, name): try: return self.obj_attr_is_set(name) except AttributeError: return False @classmethod def obj_name(cls): """Return the object's name Return a canonical name for this object which will be used over the wire for remote hydration. """ return cls.__name__ @classmethod def _obj_primitive_key(cls, field): return '%s.%s' % (cls.OBJ_SERIAL_NAMESPACE, field) @classmethod def _obj_primitive_field(cls, primitive, field, default=obj_fields.UnspecifiedDefault): key = cls._obj_primitive_key(field) if default == obj_fields.UnspecifiedDefault: return primitive[key] else: return primitive.get(key, default) @classmethod def obj_class_from_name(cls, objname, objver): """Returns a class from the registry based on a name and version.""" if objname not in VersionedObjectRegistry.obj_classes(): LOG.error(_LE('Unable to instantiate unregistered object type ' '%(objtype)s'), dict(objtype=objname)) raise exception.UnsupportedObjectError(objtype=objname) # NOTE(comstud): If there's not an exact match, return the highest # compatible version. The objects stored in the class are sorted # such that highest version is first, so only set compatible_match # once below. compatible_match = None for objclass in VersionedObjectRegistry.obj_classes()[objname]: if objclass.VERSION == objver: return objclass if (not compatible_match and vutils.is_compatible(objver, objclass.VERSION)): compatible_match = objclass if compatible_match: return compatible_match # As mentioned above, latest version is always first in the list. latest_ver = VersionedObjectRegistry.obj_classes()[objname][0].VERSION raise exception.IncompatibleObjectVersion(objname=objname, objver=objver, supported=latest_ver) @classmethod def _obj_from_primitive(cls, context, objver, primitive): self = cls() self._context = context self.VERSION = objver objdata = cls._obj_primitive_field(primitive, 'data') changes = cls._obj_primitive_field(primitive, 'changes', []) for name, field in self.fields.items(): if name in objdata: setattr(self, name, field.from_primitive(self, name, objdata[name])) self._changed_fields = set([x for x in changes if x in self.fields]) return self @classmethod def obj_from_primitive(cls, primitive, context=None): """Object field-by-field hydration.""" objns = cls._obj_primitive_field(primitive, 'namespace') objname = cls._obj_primitive_field(primitive, 'name') objver = cls._obj_primitive_field(primitive, 'version') if objns != cls.OBJ_PROJECT_NAMESPACE: # NOTE(danms): We don't do anything with this now, but it's # there for "the future" raise exception.UnsupportedObjectError( objtype='%s.%s' % (objns, objname)) objclass = cls.obj_class_from_name(objname, objver) return objclass._obj_from_primitive(context, objver, primitive) def __deepcopy__(self, memo): """Efficiently make a deep copy of this object.""" # NOTE(danms): A naive deepcopy would copy more than we need, # and since we have knowledge of the volatile bits of the # object, we can be smarter here. Also, nested entities within # some objects may be uncopyable, so we can avoid those sorts # of issues by copying only our field data. nobj = self.__class__() nobj._context = self._context for name in self.fields: if self.obj_attr_is_set(name): nval = copy.deepcopy(getattr(self, name), memo) setattr(nobj, name, nval) nobj._changed_fields = set(self._changed_fields) return nobj def obj_clone(self): """Create a copy.""" return copy.deepcopy(self) def _obj_relationship_for(self, field, target_version): # NOTE(danms): We need to be graceful about not having the temporary # version manifest if called from obj_make_compatible(). if (not hasattr(self, '_obj_version_manifest') or self._obj_version_manifest is None): try: return self.obj_relationships[field] except KeyError: raise exception.ObjectActionError( action='obj_make_compatible', reason='No rule for %s' % field) objname = self.fields[field].objname if objname not in self._obj_version_manifest: return # NOTE(danms): Compute a relationship mapping that looks like # what the caller expects. return [(target_version, self._obj_version_manifest[objname])] def _obj_make_obj_compatible(self, primitive, target_version, field): """Backlevel a sub-object based on our versioning rules. This is responsible for backporting objects contained within this object's primitive according to a set of rules we maintain about version dependencies between objects. This requires that the obj_relationships table in this object is correct and up-to-date. :param:primitive: The primitive version of this object :param:target_version: The version string requested for this object :param:field: The name of the field in this object containing the sub-object to be backported """ relationship_map = self._obj_relationship_for(field, target_version) if not relationship_map: # NOTE(danms): This means the field was not specified in the # version manifest from the client, so it must not want this # field, so skip. return try: _get_subobject_version(target_version, relationship_map, lambda ver: _do_subobject_backport( ver, self, field, primitive)) except exception.TargetBeforeSubobjectExistedException: # Subobject did not exist, so delete it from the primitive del primitive[field] def obj_make_compatible(self, primitive, target_version): """Make an object representation compatible with a target version. This is responsible for taking the primitive representation of an object and making it suitable for the given target_version. This may mean converting the format of object attributes, removing attributes that have been added since the target version, etc. In general: - If a new version of an object adds a field, this routine should remove it for older versions. - If a new version changed or restricted the format of a field, this should convert it back to something a client knowing only of the older version will tolerate. - If an object that this object depends on is bumped, then this object should also take a version bump. Then, this routine should backlevel the dependent object (by calling its obj_make_compatible()) if the requested version of this object is older than the version where the new dependent object was added. :param primitive: The result of :meth:`obj_to_primitive` :param target_version: The version string requested by the recipient of the object :raises: :exc:`oslo_versionedobjects.exception.UnsupportedObjectError` if conversion is not possible for some reason """ for key, field in self.fields.items(): if not isinstance(field, (obj_fields.ObjectField, obj_fields.ListOfObjectsField)): continue if not self.obj_attr_is_set(key): continue self._obj_make_obj_compatible(primitive, target_version, key) def obj_make_compatible_from_manifest(self, primitive, target_version, version_manifest): # NOTE(danms): Stash the manifest on the object so we can use it in # the deeper layers. We do this because obj_make_compatible() is # defined library API at this point, yet we need to get this manifest # to the other bits that get called so we can propagate it to child # calls. It's not pretty, but a tactical solution. Ideally we will # either evolve or deprecate obj_make_compatible() in a major version # bump. self._obj_version_manifest = version_manifest try: return self.obj_make_compatible(primitive, target_version) finally: delattr(self, '_obj_version_manifest') def obj_to_primitive(self, target_version=None, version_manifest=None): """Simple base-case dehydration. This calls to_primitive() for each item in fields. """ if target_version is None: target_version = self.VERSION if (vutils.convert_version_to_tuple(target_version) > vutils.convert_version_to_tuple(self.VERSION)): raise exception.InvalidTargetVersion(version=target_version) primitive = dict() for name, field in self.fields.items(): if self.obj_attr_is_set(name): primitive[name] = field.to_primitive(self, name, getattr(self, name)) # NOTE(danms): If we know we're being asked for a different version, # then do the compat step. However, even if we think we're not, # we may have sub-objects that need it, so if we have a manifest we # have to traverse this object just in case. Previously, we # required a parent version bump for any child, so the target # check was enough. if target_version != self.VERSION or version_manifest: self.obj_make_compatible_from_manifest(primitive, target_version, version_manifest) obj = {self._obj_primitive_key('name'): self.obj_name(), self._obj_primitive_key('namespace'): ( self.OBJ_PROJECT_NAMESPACE), self._obj_primitive_key('version'): target_version, self._obj_primitive_key('data'): primitive} if self.obj_what_changed(): obj[self._obj_primitive_key('changes')] = list( self.obj_what_changed()) return obj def obj_set_defaults(self, *attrs): if not attrs: attrs = [name for name, field in self.fields.items() if field.default != obj_fields.UnspecifiedDefault] for attr in attrs: default = copy.deepcopy(self.fields[attr].default) if default is obj_fields.UnspecifiedDefault: raise exception.ObjectActionError( action='set_defaults', reason='No default set for field %s' % attr) if not self.obj_attr_is_set(attr): setattr(self, attr, default) def obj_load_attr(self, attrname): """Load an additional attribute from the real object. This should load self.$attrname and cache any data that might be useful for future load operations. """ raise NotImplementedError( _("Cannot load '%s' in the base class") % attrname) def save(self, context): """Save the changed fields back to the store. This is optional for subclasses, but is presented here in the base class for consistency among those that do. """ raise NotImplementedError(_('Cannot save anything in the base class')) def obj_what_changed(self): """Returns a set of fields that have been modified.""" changes = set(self._changed_fields) for field in self.fields: if (self.obj_attr_is_set(field) and isinstance(getattr(self, field), VersionedObject) and getattr(self, field).obj_what_changed()): changes.add(field) return changes def obj_get_changes(self): """Returns a dict of changed fields and their new values.""" changes = {} for key in self.obj_what_changed(): changes[key] = getattr(self, key) return changes def obj_reset_changes(self, fields=None, recursive=False): """Reset the list of fields that have been changed. :param fields: List of fields to reset, or "all" if None. :param recursive: Call obj_reset_changes(recursive=True) on any sub-objects within the list of fields being reset. This is NOT "revert to previous values". Specifying fields on recursive resets will only be honored at the top level. Everything below the top will reset all. """ if recursive: for field in self.obj_get_changes(): # Ignore fields not in requested set (if applicable) if fields and field not in fields: continue # Skip any fields that are unset if not self.obj_attr_is_set(field): continue value = getattr(self, field) # Don't reset nulled fields if value is None: continue # Reset straight Object and ListOfObjects fields if isinstance(self.fields[field], obj_fields.ObjectField): value.obj_reset_changes(recursive=True) elif isinstance(self.fields[field], obj_fields.ListOfObjectsField): for thing in value: thing.obj_reset_changes(recursive=True) if fields: self._changed_fields -= set(fields) else: self._changed_fields.clear() def obj_attr_is_set(self, attrname): """Test object to see if attrname is present. Returns True if the named attribute has a value set, or False if not. Raises AttributeError if attrname is not a valid attribute for this object. """ if attrname not in self.obj_fields: raise AttributeError( _("%(objname)s object has no attribute '%(attrname)s'") % {'objname': self.obj_name(), 'attrname': attrname}) return hasattr(self, _get_attrname(attrname)) @property def obj_fields(self): return list(self.fields.keys()) + self.obj_extra_fields class ComparableVersionedObject(object): """Mix-in to provide comparison methods When objects are to be compared with each other (in tests for example), this mixin can be used. """ def __eq__(self, obj): # FIXME(inc0): this can return incorrect value if we consider partially # loaded objects from db and fields which are dropped out differ return self.obj_to_primitive() == obj.obj_to_primitive() class VersionedObjectDictCompat(object): """Mix-in to provide dictionary key access compatibility If an object needs to support attribute access using dictionary items instead of object attributes, inherit from this class. This should only be used as a temporary measure until all callers are converted to use modern attribute access. """ def __iter__(self): for name in self.obj_fields: if (self.obj_attr_is_set(name) or name in self.obj_extra_fields): yield name iterkeys = __iter__ def itervalues(self): for name in self: yield getattr(self, name) def iteritems(self): for name in self: yield name, getattr(self, name) if six.PY3: # NOTE(haypo): Python 3 dictionaries don't have iterkeys(), # itervalues() or iteritems() methods. These methods are provided to # ease the transition from Python 2 to Python 3. keys = iterkeys values = itervalues items = iteritems else: def keys(self): return list(self.iterkeys()) def values(self): return list(self.itervalues()) def items(self): return list(self.iteritems()) def __getitem__(self, name): return getattr(self, name) def __setitem__(self, name, value): setattr(self, name, value) def get(self, key, value=_NotSpecifiedSentinel): if key not in self.obj_fields: raise AttributeError("'%s' object has no attribute '%s'" % ( self.__class__, key)) if value != _NotSpecifiedSentinel and not self.obj_attr_is_set(key): return value else: return getattr(self, key) def update(self, updates): for key, value in updates.items(): setattr(self, key, value) class ObjectListBase(collections.Sequence): """Mixin class for lists of objects. This mixin class can be added as a base class for an object that is implementing a list of objects. It adds a single field of 'objects', which is the list store, and behaves like a list itself. It supports serialization of the list of objects automatically. """ fields = { 'objects': obj_fields.ListOfObjectsField('VersionedObject'), } # This is a dictionary of my_version:child_version mappings so that # we can support backleveling our contents based on the version # requested of the list object. child_versions = {} def __init__(self, *args, **kwargs): super(ObjectListBase, self).__init__(*args, **kwargs) if 'objects' not in kwargs: self.objects = [] self._changed_fields.discard('objects') def __len__(self): """List length.""" return len(self.objects) def __getitem__(self, index): """List index access.""" if isinstance(index, slice): new_obj = self.__class__() new_obj.objects = self.objects[index] # NOTE(danms): We must be mixed in with a VersionedObject! new_obj.obj_reset_changes() new_obj._context = self._context return new_obj return self.objects[index] def sort(self, key=None, reverse=False): self.objects.sort(key=key, reverse=reverse) def obj_make_compatible(self, primitive, target_version): # Give priority to using child_versions, if that isn't set, try # obj_relationships if self.child_versions: relationships = self.child_versions.items() else: try: relationships = self._obj_relationship_for('objects', target_version) except exception.ObjectActionError: # No relationship for this found in manifest or # in obj_relationships relationships = {} try: # NOTE(rlrossit): If we have no version information, just # backport to child version 1.0 (maintaining default # behavior) if relationships: _get_subobject_version(target_version, relationships, lambda ver: _do_subobject_backport( ver, self, 'objects', primitive)) else: _do_subobject_backport('1.0', self, 'objects', primitive) except exception.TargetBeforeSubobjectExistedException: # Child did not exist, so delete it from the primitive del primitive['objects'] def obj_what_changed(self): changes = set(self._changed_fields) for child in self.objects: if child.obj_what_changed(): changes.add('objects') return changes class VersionedObjectSerializer(messaging.NoOpSerializer): """A VersionedObject-aware Serializer. This implements the Oslo Serializer interface and provides the ability to serialize and deserialize VersionedObject entities. Any service that needs to accept or return VersionedObjects as arguments or result values should pass this to its RPCClient and RPCServer objects. """ # Base class to use for object hydration OBJ_BASE_CLASS = VersionedObject def _do_backport(self, context, objprim, objclass): obj_versions = obj_tree_get_versions(objclass.obj_name()) indirection_api = self.OBJ_BASE_CLASS.indirection_api try: return indirection_api.object_backport_versions( context, objprim, obj_versions) except NotImplementedError: # FIXME(danms): Maybe start to warn here about deprecation? return indirection_api.object_backport(context, objprim, objclass.VERSION) def _process_object(self, context, objprim): try: return self.OBJ_BASE_CLASS.obj_from_primitive( objprim, context=context) except exception.IncompatibleObjectVersion: with excutils.save_and_reraise_exception(reraise=False) as ctxt: verkey = \ '%s.version' % self.OBJ_BASE_CLASS.OBJ_SERIAL_NAMESPACE objver = objprim[verkey] if objver.count('.') == 2: # NOTE(danms): For our purposes, the .z part of the version # should be safe to accept without requiring a backport objprim[verkey] = \ '.'.join(objver.split('.')[:2]) return self._process_object(context, objprim) namekey = '%s.name' % self.OBJ_BASE_CLASS.OBJ_SERIAL_NAMESPACE objname = objprim[namekey] supported = VersionedObjectRegistry.obj_classes().get(objname, []) if self.OBJ_BASE_CLASS.indirection_api and supported: return self._do_backport(context, objprim, supported[0]) else: ctxt.reraise = True def _process_iterable(self, context, action_fn, values): """Process an iterable, taking an action on each value. :param:context: Request context :param:action_fn: Action to take on each item in values :param:values: Iterable container of things to take action on :returns: A new container of the same type (except set) with items from values having had action applied. """ iterable = values.__class__ if issubclass(iterable, dict): return iterable([(k, action_fn(context, v)) for k, v in six.iteritems(values)]) else: # NOTE(danms, gibi) A set can't have an unhashable value inside, # such as a dict. Convert the set to list, which is fine, since we # can't send them over RPC anyway. We convert it to list as this # way there will be no semantic change between the fake rpc driver # used in functional test and a normal rpc driver. if iterable == set: iterable = list return iterable([action_fn(context, value) for value in values]) def serialize_entity(self, context, entity): if isinstance(entity, (tuple, list, set, dict)): entity = self._process_iterable(context, self.serialize_entity, entity) elif (hasattr(entity, 'obj_to_primitive') and callable(entity.obj_to_primitive)): entity = entity.obj_to_primitive() return entity def deserialize_entity(self, context, entity): namekey = '%s.name' % self.OBJ_BASE_CLASS.OBJ_SERIAL_NAMESPACE if isinstance(entity, dict) and namekey in entity: entity = self._process_object(context, entity) elif isinstance(entity, (tuple, list, set, dict)): entity = self._process_iterable(context, self.deserialize_entity, entity) return entity @six.add_metaclass(abc.ABCMeta) class VersionedObjectIndirectionAPI(object): def object_action(self, context, objinst, objmethod, args, kwargs): """Perform an action on a VersionedObject instance. When indirection_api is set on a VersionedObject (to a class implementing this interface), method calls on remotable methods will cause this to be executed to actually make the desired call. This often involves performing RPC. :param context: The context within which to perform the action :param objinst: The object instance on which to perform the action :param objmethod: The name of the action method to call :param args: The positional arguments to the action method :param kwargs: The keyword arguments to the action method :returns: The result of the action method """ pass def object_class_action(self, context, objname, objmethod, objver, args, kwargs): """.. deprecated:: 0.10.0 Use :func:`object_class_action_versions` instead. Perform an action on a VersionedObject class. When indirection_api is set on a VersionedObject (to a class implementing this interface), classmethod calls on remotable_classmethod methods will cause this to be executed to actually make the desired call. This usually involves performing RPC. :param context: The context within which to perform the action :param objname: The registry name of the object :param objmethod: The name of the action method to call :param objver: The (remote) version of the object on which the action is being taken :param args: The positional arguments to the action method :param kwargs: The keyword arguments to the action method :returns: The result of the action method, which may (or may not) be an instance of the implementing VersionedObject class. """ pass def object_class_action_versions(self, context, objname, objmethod, object_versions, args, kwargs): """Perform an action on a VersionedObject class. When indirection_api is set on a VersionedObject (to a class implementing this interface), classmethod calls on remotable_classmethod methods will cause this to be executed to actually make the desired call. This usually involves performing RPC. This differs from object_class_action() in that it is provided with object_versions, a manifest of client-side object versions for easier nested backports. The manifest is the result of calling obj_tree_get_versions(). NOTE: This was not in the initial spec for this interface, so the base class raises NotImplementedError if you don't implement it. For backports, this method will be tried first, and if unimplemented, will fall back to object_class_action(). New implementations should provide this method instead of object_class_action() :param context: The context within which to perform the action :param objname: The registry name of the object :param objmethod: The name of the action method to call :param object_versions: A dict of {objname: version} mappings :param args: The positional arguments to the action method :param kwargs: The keyword arguments to the action method :returns: The result of the action method, which may (or may not) be an instance of the implementing VersionedObject class. """ warnings.warn('object_class_action() is deprecated in favor of ' 'object_class_action_versions() and will be removed ' 'in a later release', DeprecationWarning) raise NotImplementedError('Multi-version class action not supported') def object_backport(self, context, objinst, target_version): """.. deprecated:: 0.10.0 Use :func:`object_backport_versions` instead. Perform a backport of an object instance to a specified version. When indirection_api is set on a VersionedObject (to a class implementing this interface), the default behavior of the base VersionedObjectSerializer, upon receiving an object with a version newer than what is in the lcoal registry, is to call this method to request a backport of the object. In an environment where there is an RPC-able service on the bus which can gracefully downgrade newer objects for older services, this method services as a translation mechanism for older code when receiving objects from newer code. NOTE: This older/original method is soon to be deprecated. When a backport is required, the newer object_backport_versions() will be tried, and if it raises NotImplementedError, then we will fall back to this (less optimal) method. :param context: The context within which to perform the backport :param objinst: An instance of a VersionedObject to be backported :param target_version: The maximum version of the objinst's class that is understood by the requesting host. :returns: The downgraded instance of objinst """ pass def object_backport_versions(self, context, objinst, object_versions): """Perform a backport of an object instance. This method is basically just like object_backport() but instead of providing a specific target version for the toplevel object and relying on the service-side mapping to handle sub-objects, this sends a mapping of all the dependent objects and their client-supported versions. The server will backport objects within the tree starting at objinst to the versions specified in object_versions, removing objects that have no entry. Use obj_tree_get_versions() to generate this mapping. NOTE: This was not in the initial spec for this interface, so the base class raises NotImplementedError if you don't implement it. For backports, this method will be tried first, and if unimplemented, will fall back to object_backport(). :param context: The context within which to perform the backport :param objinst: An instance of a VersionedObject to be backported :param object_versions: A dict of {objname: version} mappings """ warnings.warn('object_backport() is deprecated in favor of ' 'object_backport_versions() and will be removed ' 'in a later release', DeprecationWarning) raise NotImplementedError('Multi-version backport not supported') def obj_make_list(context, list_obj, item_cls, db_list, **extra_args): """Construct an object list from a list of primitives. This calls item_cls._from_db_object() on each item of db_list, and adds the resulting object to list_obj. :param:context: Request context :param:list_obj: An ObjectListBase object :param:item_cls: The VersionedObject class of the objects within the list :param:db_list: The list of primitives to convert to objects :param:extra_args: Extra arguments to pass to _from_db_object() :returns: list_obj """ list_obj.objects = [] for db_item in db_list: item = item_cls._from_db_object(context, item_cls(), db_item, **extra_args) list_obj.objects.append(item) list_obj._context = context list_obj.obj_reset_changes() return list_obj def obj_tree_get_versions(objname, tree=None): """Construct a mapping of dependent object versions. This method builds a list of dependent object versions given a top- level object with other objects as fields. It walks the tree recursively to determine all the objects (by symbolic name) that could be contained within the top-level object, and the maximum versions of each. The result is a dict like: {'MyObject': '1.23', ... } :param objname: The top-level object at which to start :param tree: Used internally, pass None here. :returns: A dictionary of object names and versions """ if tree is None: tree = {} if objname in tree: return tree objclass = VersionedObjectRegistry.obj_classes()[objname][0] tree[objname] = objclass.VERSION for field_name in objclass.fields: field = objclass.fields[field_name] if isinstance(field, obj_fields.ObjectField): child_cls = field._type._obj_name elif isinstance(field, obj_fields.ListOfObjectsField): child_cls = field._type._element_type._type._obj_name else: continue obj_tree_get_versions(child_cls, tree=tree) return tree def _get_subobject_version(tgt_version, relationships, backport_func): """Get the version to which we need to convert a subobject. This uses the relationships between a parent and a subobject, along with the target parent version, to decide the version we need to convert a subobject to. If the subobject did not exist in the parent at the target version, TargetBeforeChildExistedException is raised. If there is a need to backport, backport_func is called and the subobject version to backport to is passed in. :param tgt_version: The version we are converting the parent to :param relationships: A list of (parent, subobject) version tuples :param backport_func: A backport function that takes in the subobject version :returns: The version we need to convert the subobject to """ tgt = vutils.convert_version_to_tuple(tgt_version) for index, versions in enumerate(relationships): parent, child = versions parent = vutils.convert_version_to_tuple(parent) if tgt < parent: if index == 0: # We're backporting to a version of the parent that did # not contain this subobject raise exception.TargetBeforeSubobjectExistedException( target_version=tgt_version) else: # We're in a gap between index-1 and index, so set the desired # version to the previous index's version child = relationships[index - 1][1] backport_func(child) return elif tgt == parent: # We found the version we want, so backport to it backport_func(child) return def _do_subobject_backport(to_version, parent, field, primitive): obj = getattr(parent, field) manifest = (hasattr(parent, '_obj_version_manifest') and parent._obj_version_manifest or None) if isinstance(obj, VersionedObject): obj.obj_make_compatible_from_manifest( obj._obj_primitive_field(primitive[field], 'data'), to_version, version_manifest=manifest) ver_key = obj._obj_primitive_key('version') primitive[field][ver_key] = to_version elif isinstance(obj, list): for i, element in enumerate(obj): element.obj_make_compatible_from_manifest( element._obj_primitive_field(primitive[field][i], 'data'), to_version, version_manifest=manifest) ver_key = element._obj_primitive_key('version') primitive[field][i][ver_key] = to_version