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-# Protocol Buffers - Google's data interchange format
-# Copyright 2008 Google Inc. All rights reserved.
-# https://developers.google.com/protocol-buffers/
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met:
-#
-# * Redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer.
-# * Redistributions in binary form must reproduce the above
-# copyright notice, this list of conditions and the following disclaimer
-# in the documentation and/or other materials provided with the
-# distribution.
-# * Neither the name of Google Inc. nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-# This code is meant to work on Python 2.4 and above only.
-#
-# TODO(robinson): Helpers for verbose, common checks like seeing if a
-# descriptor's cpp_type is CPPTYPE_MESSAGE.
-
-"""Contains a metaclass and helper functions used to create
-protocol message classes from Descriptor objects at runtime.
-
-Recall that a metaclass is the "type" of a class.
-(A class is to a metaclass what an instance is to a class.)
-
-In this case, we use the GeneratedProtocolMessageType metaclass
-to inject all the useful functionality into the classes
-output by the protocol compiler at compile-time.
-
-The upshot of all this is that the real implementation
-details for ALL pure-Python protocol buffers are *here in
-this file*.
-"""
-
-__author__ = 'robinson@google.com (Will Robinson)'
-
-from io import BytesIO
-import sys
-import struct
-import weakref
-
-import six
-try:
- import six.moves.copyreg as copyreg
-except ImportError:
- # On some platforms, for example gMac, we run native Python because there is
- # nothing like hermetic Python. This means lesser control on the system and
- # the six.moves package may be missing (is missing on 20150321 on gMac). Be
- # extra conservative and try to load the old replacement if it fails.
- import copy_reg as copyreg
-
-# We use "as" to avoid name collisions with variables.
-from google.protobuf.internal import containers
-from google.protobuf.internal import decoder
-from google.protobuf.internal import encoder
-from google.protobuf.internal import enum_type_wrapper
-from google.protobuf.internal import message_listener as message_listener_mod
-from google.protobuf.internal import type_checkers
-from google.protobuf.internal import well_known_types
-from google.protobuf.internal import wire_format
-from google.protobuf import descriptor as descriptor_mod
-from google.protobuf import message as message_mod
-from google.protobuf import text_format
-
-_FieldDescriptor = descriptor_mod.FieldDescriptor
-_AnyFullTypeName = 'google.protobuf.Any'
-
-
-class GeneratedProtocolMessageType(type):
-
- """Metaclass for protocol message classes created at runtime from Descriptors.
-
- We add implementations for all methods described in the Message class. We
- also create properties to allow getting/setting all fields in the protocol
- message. Finally, we create slots to prevent users from accidentally
- "setting" nonexistent fields in the protocol message, which then wouldn't get
- serialized / deserialized properly.
-
- The protocol compiler currently uses this metaclass to create protocol
- message classes at runtime. Clients can also manually create their own
- classes at runtime, as in this example:
-
- mydescriptor = Descriptor(.....)
- factory = symbol_database.Default()
- factory.pool.AddDescriptor(mydescriptor)
- MyProtoClass = factory.GetPrototype(mydescriptor)
- myproto_instance = MyProtoClass()
- myproto.foo_field = 23
- ...
- """
-
- # Must be consistent with the protocol-compiler code in
- # proto2/compiler/internal/generator.*.
- _DESCRIPTOR_KEY = 'DESCRIPTOR'
-
- def __new__(cls, name, bases, dictionary):
- """Custom allocation for runtime-generated class types.
-
- We override __new__ because this is apparently the only place
- where we can meaningfully set __slots__ on the class we're creating(?).
- (The interplay between metaclasses and slots is not very well-documented).
-
- Args:
- name: Name of the class (ignored, but required by the
- metaclass protocol).
- bases: Base classes of the class we're constructing.
- (Should be message.Message). We ignore this field, but
- it's required by the metaclass protocol
- dictionary: The class dictionary of the class we're
- constructing. dictionary[_DESCRIPTOR_KEY] must contain
- a Descriptor object describing this protocol message
- type.
-
- Returns:
- Newly-allocated class.
- """
- descriptor = dictionary[GeneratedProtocolMessageType._DESCRIPTOR_KEY]
- if descriptor.full_name in well_known_types.WKTBASES:
- bases += (well_known_types.WKTBASES[descriptor.full_name],)
- _AddClassAttributesForNestedExtensions(descriptor, dictionary)
- _AddSlots(descriptor, dictionary)
-
- superclass = super(GeneratedProtocolMessageType, cls)
- new_class = superclass.__new__(cls, name, bases, dictionary)
- return new_class
-
- def __init__(cls, name, bases, dictionary):
- """Here we perform the majority of our work on the class.
- We add enum getters, an __init__ method, implementations
- of all Message methods, and properties for all fields
- in the protocol type.
-
- Args:
- name: Name of the class (ignored, but required by the
- metaclass protocol).
- bases: Base classes of the class we're constructing.
- (Should be message.Message). We ignore this field, but
- it's required by the metaclass protocol
- dictionary: The class dictionary of the class we're
- constructing. dictionary[_DESCRIPTOR_KEY] must contain
- a Descriptor object describing this protocol message
- type.
- """
- descriptor = dictionary[GeneratedProtocolMessageType._DESCRIPTOR_KEY]
- cls._decoders_by_tag = {}
- cls._extensions_by_name = {}
- cls._extensions_by_number = {}
- if (descriptor.has_options and
- descriptor.GetOptions().message_set_wire_format):
- cls._decoders_by_tag[decoder.MESSAGE_SET_ITEM_TAG] = (
- decoder.MessageSetItemDecoder(cls._extensions_by_number), None)
-
- # Attach stuff to each FieldDescriptor for quick lookup later on.
- for field in descriptor.fields:
- _AttachFieldHelpers(cls, field)
-
- descriptor._concrete_class = cls # pylint: disable=protected-access
- _AddEnumValues(descriptor, cls)
- _AddInitMethod(descriptor, cls)
- _AddPropertiesForFields(descriptor, cls)
- _AddPropertiesForExtensions(descriptor, cls)
- _AddStaticMethods(cls)
- _AddMessageMethods(descriptor, cls)
- _AddPrivateHelperMethods(descriptor, cls)
- copyreg.pickle(cls, lambda obj: (cls, (), obj.__getstate__()))
-
- superclass = super(GeneratedProtocolMessageType, cls)
- superclass.__init__(name, bases, dictionary)
-
-
-# Stateless helpers for GeneratedProtocolMessageType below.
-# Outside clients should not access these directly.
-#
-# I opted not to make any of these methods on the metaclass, to make it more
-# clear that I'm not really using any state there and to keep clients from
-# thinking that they have direct access to these construction helpers.
-
-
-def _PropertyName(proto_field_name):
- """Returns the name of the public property attribute which
- clients can use to get and (in some cases) set the value
- of a protocol message field.
-
- Args:
- proto_field_name: The protocol message field name, exactly
- as it appears (or would appear) in a .proto file.
- """
- # TODO(robinson): Escape Python keywords (e.g., yield), and test this support.
- # nnorwitz makes my day by writing:
- # """
- # FYI. See the keyword module in the stdlib. This could be as simple as:
- #
- # if keyword.iskeyword(proto_field_name):
- # return proto_field_name + "_"
- # return proto_field_name
- # """
- # Kenton says: The above is a BAD IDEA. People rely on being able to use
- # getattr() and setattr() to reflectively manipulate field values. If we
- # rename the properties, then every such user has to also make sure to apply
- # the same transformation. Note that currently if you name a field "yield",
- # you can still access it just fine using getattr/setattr -- it's not even
- # that cumbersome to do so.
- # TODO(kenton): Remove this method entirely if/when everyone agrees with my
- # position.
- return proto_field_name
-
-
-def _VerifyExtensionHandle(message, extension_handle):
- """Verify that the given extension handle is valid."""
-
- if not isinstance(extension_handle, _FieldDescriptor):
- raise KeyError('HasExtension() expects an extension handle, got: %s' %
- extension_handle)
-
- if not extension_handle.is_extension:
- raise KeyError('"%s" is not an extension.' % extension_handle.full_name)
-
- if not extension_handle.containing_type:
- raise KeyError('"%s" is missing a containing_type.'
- % extension_handle.full_name)
-
- if extension_handle.containing_type is not message.DESCRIPTOR:
- raise KeyError('Extension "%s" extends message type "%s", but this '
- 'message is of type "%s".' %
- (extension_handle.full_name,
- extension_handle.containing_type.full_name,
- message.DESCRIPTOR.full_name))
-
-
-def _AddSlots(message_descriptor, dictionary):
- """Adds a __slots__ entry to dictionary, containing the names of all valid
- attributes for this message type.
-
- Args:
- message_descriptor: A Descriptor instance describing this message type.
- dictionary: Class dictionary to which we'll add a '__slots__' entry.
- """
- dictionary['__slots__'] = ['_cached_byte_size',
- '_cached_byte_size_dirty',
- '_fields',
- '_unknown_fields',
- '_is_present_in_parent',
- '_listener',
- '_listener_for_children',
- '__weakref__',
- '_oneofs']
-
-
-def _IsMessageSetExtension(field):
- return (field.is_extension and
- field.containing_type.has_options and
- field.containing_type.GetOptions().message_set_wire_format and
- field.type == _FieldDescriptor.TYPE_MESSAGE and
- field.label == _FieldDescriptor.LABEL_OPTIONAL)
-
-
-def _IsMapField(field):
- return (field.type == _FieldDescriptor.TYPE_MESSAGE and
- field.message_type.has_options and
- field.message_type.GetOptions().map_entry)
-
-
-def _IsMessageMapField(field):
- value_type = field.message_type.fields_by_name["value"]
- return value_type.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE
-
-
-def _AttachFieldHelpers(cls, field_descriptor):
- is_repeated = (field_descriptor.label == _FieldDescriptor.LABEL_REPEATED)
- is_packable = (is_repeated and
- wire_format.IsTypePackable(field_descriptor.type))
- if not is_packable:
- is_packed = False
- elif field_descriptor.containing_type.syntax == "proto2":
- is_packed = (field_descriptor.has_options and
- field_descriptor.GetOptions().packed)
- else:
- has_packed_false = (field_descriptor.has_options and
- field_descriptor.GetOptions().HasField("packed") and
- field_descriptor.GetOptions().packed == False)
- is_packed = not has_packed_false
- is_map_entry = _IsMapField(field_descriptor)
-
- if is_map_entry:
- field_encoder = encoder.MapEncoder(field_descriptor)
- sizer = encoder.MapSizer(field_descriptor)
- elif _IsMessageSetExtension(field_descriptor):
- field_encoder = encoder.MessageSetItemEncoder(field_descriptor.number)
- sizer = encoder.MessageSetItemSizer(field_descriptor.number)
- else:
- field_encoder = type_checkers.TYPE_TO_ENCODER[field_descriptor.type](
- field_descriptor.number, is_repeated, is_packed)
- sizer = type_checkers.TYPE_TO_SIZER[field_descriptor.type](
- field_descriptor.number, is_repeated, is_packed)
-
- field_descriptor._encoder = field_encoder
- field_descriptor._sizer = sizer
- field_descriptor._default_constructor = _DefaultValueConstructorForField(
- field_descriptor)
-
- def AddDecoder(wiretype, is_packed):
- tag_bytes = encoder.TagBytes(field_descriptor.number, wiretype)
- decode_type = field_descriptor.type
- if (decode_type == _FieldDescriptor.TYPE_ENUM and
- type_checkers.SupportsOpenEnums(field_descriptor)):
- decode_type = _FieldDescriptor.TYPE_INT32
-
- oneof_descriptor = None
- if field_descriptor.containing_oneof is not None:
- oneof_descriptor = field_descriptor
-
- if is_map_entry:
- is_message_map = _IsMessageMapField(field_descriptor)
-
- field_decoder = decoder.MapDecoder(
- field_descriptor, _GetInitializeDefaultForMap(field_descriptor),
- is_message_map)
- else:
- field_decoder = type_checkers.TYPE_TO_DECODER[decode_type](
- field_descriptor.number, is_repeated, is_packed,
- field_descriptor, field_descriptor._default_constructor)
-
- cls._decoders_by_tag[tag_bytes] = (field_decoder, oneof_descriptor)
-
- AddDecoder(type_checkers.FIELD_TYPE_TO_WIRE_TYPE[field_descriptor.type],
- False)
-
- if is_repeated and wire_format.IsTypePackable(field_descriptor.type):
- # To support wire compatibility of adding packed = true, add a decoder for
- # packed values regardless of the field's options.
- AddDecoder(wire_format.WIRETYPE_LENGTH_DELIMITED, True)
-
-
-def _AddClassAttributesForNestedExtensions(descriptor, dictionary):
- extension_dict = descriptor.extensions_by_name
- for extension_name, extension_field in extension_dict.items():
- assert extension_name not in dictionary
- dictionary[extension_name] = extension_field
-
-
-def _AddEnumValues(descriptor, cls):
- """Sets class-level attributes for all enum fields defined in this message.
-
- Also exporting a class-level object that can name enum values.
-
- Args:
- descriptor: Descriptor object for this message type.
- cls: Class we're constructing for this message type.
- """
- for enum_type in descriptor.enum_types:
- setattr(cls, enum_type.name, enum_type_wrapper.EnumTypeWrapper(enum_type))
- for enum_value in enum_type.values:
- setattr(cls, enum_value.name, enum_value.number)
-
-
-def _GetInitializeDefaultForMap(field):
- if field.label != _FieldDescriptor.LABEL_REPEATED:
- raise ValueError('map_entry set on non-repeated field %s' % (
- field.name))
- fields_by_name = field.message_type.fields_by_name
- key_checker = type_checkers.GetTypeChecker(fields_by_name['key'])
-
- value_field = fields_by_name['value']
- if _IsMessageMapField(field):
- def MakeMessageMapDefault(message):
- return containers.MessageMap(
- message._listener_for_children, value_field.message_type, key_checker)
- return MakeMessageMapDefault
- else:
- value_checker = type_checkers.GetTypeChecker(value_field)
- def MakePrimitiveMapDefault(message):
- return containers.ScalarMap(
- message._listener_for_children, key_checker, value_checker)
- return MakePrimitiveMapDefault
-
-def _DefaultValueConstructorForField(field):
- """Returns a function which returns a default value for a field.
-
- Args:
- field: FieldDescriptor object for this field.
-
- The returned function has one argument:
- message: Message instance containing this field, or a weakref proxy
- of same.
-
- That function in turn returns a default value for this field. The default
- value may refer back to |message| via a weak reference.
- """
-
- if _IsMapField(field):
- return _GetInitializeDefaultForMap(field)
-
- if field.label == _FieldDescriptor.LABEL_REPEATED:
- if field.has_default_value and field.default_value != []:
- raise ValueError('Repeated field default value not empty list: %s' % (
- field.default_value))
- if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
- # We can't look at _concrete_class yet since it might not have
- # been set. (Depends on order in which we initialize the classes).
- message_type = field.message_type
- def MakeRepeatedMessageDefault(message):
- return containers.RepeatedCompositeFieldContainer(
- message._listener_for_children, field.message_type)
- return MakeRepeatedMessageDefault
- else:
- type_checker = type_checkers.GetTypeChecker(field)
- def MakeRepeatedScalarDefault(message):
- return containers.RepeatedScalarFieldContainer(
- message._listener_for_children, type_checker)
- return MakeRepeatedScalarDefault
-
- if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
- # _concrete_class may not yet be initialized.
- message_type = field.message_type
- def MakeSubMessageDefault(message):
- result = message_type._concrete_class()
- result._SetListener(
- _OneofListener(message, field)
- if field.containing_oneof is not None
- else message._listener_for_children)
- return result
- return MakeSubMessageDefault
-
- def MakeScalarDefault(message):
- # TODO(protobuf-team): This may be broken since there may not be
- # default_value. Combine with has_default_value somehow.
- return field.default_value
- return MakeScalarDefault
-
-
-def _ReraiseTypeErrorWithFieldName(message_name, field_name):
- """Re-raise the currently-handled TypeError with the field name added."""
- exc = sys.exc_info()[1]
- if len(exc.args) == 1 and type(exc) is TypeError:
- # simple TypeError; add field name to exception message
- exc = TypeError('%s for field %s.%s' % (str(exc), message_name, field_name))
-
- # re-raise possibly-amended exception with original traceback:
- six.reraise(type(exc), exc, sys.exc_info()[2])
-
-
-def _AddInitMethod(message_descriptor, cls):
- """Adds an __init__ method to cls."""
-
- def _GetIntegerEnumValue(enum_type, value):
- """Convert a string or integer enum value to an integer.
-
- If the value is a string, it is converted to the enum value in
- enum_type with the same name. If the value is not a string, it's
- returned as-is. (No conversion or bounds-checking is done.)
- """
- if isinstance(value, six.string_types):
- try:
- return enum_type.values_by_name[value].number
- except KeyError:
- raise ValueError('Enum type %s: unknown label "%s"' % (
- enum_type.full_name, value))
- return value
-
- def init(self, **kwargs):
- self._cached_byte_size = 0
- self._cached_byte_size_dirty = len(kwargs) > 0
- self._fields = {}
- # Contains a mapping from oneof field descriptors to the descriptor
- # of the currently set field in that oneof field.
- self._oneofs = {}
-
- # _unknown_fields is () when empty for efficiency, and will be turned into
- # a list if fields are added.
- self._unknown_fields = ()
- self._is_present_in_parent = False
- self._listener = message_listener_mod.NullMessageListener()
- self._listener_for_children = _Listener(self)
- for field_name, field_value in kwargs.items():
- field = _GetFieldByName(message_descriptor, field_name)
- if field is None:
- raise TypeError("%s() got an unexpected keyword argument '%s'" %
- (message_descriptor.name, field_name))
- if field_value is None:
- # field=None is the same as no field at all.
- continue
- if field.label == _FieldDescriptor.LABEL_REPEATED:
- copy = field._default_constructor(self)
- if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE: # Composite
- if _IsMapField(field):
- if _IsMessageMapField(field):
- for key in field_value:
- copy[key].MergeFrom(field_value[key])
- else:
- copy.update(field_value)
- else:
- for val in field_value:
- if isinstance(val, dict):
- copy.add(**val)
- else:
- copy.add().MergeFrom(val)
- else: # Scalar
- if field.cpp_type == _FieldDescriptor.CPPTYPE_ENUM:
- field_value = [_GetIntegerEnumValue(field.enum_type, val)
- for val in field_value]
- copy.extend(field_value)
- self._fields[field] = copy
- elif field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
- copy = field._default_constructor(self)
- new_val = field_value
- if isinstance(field_value, dict):
- new_val = field.message_type._concrete_class(**field_value)
- try:
- copy.MergeFrom(new_val)
- except TypeError:
- _ReraiseTypeErrorWithFieldName(message_descriptor.name, field_name)
- self._fields[field] = copy
- else:
- if field.cpp_type == _FieldDescriptor.CPPTYPE_ENUM:
- field_value = _GetIntegerEnumValue(field.enum_type, field_value)
- try:
- setattr(self, field_name, field_value)
- except TypeError:
- _ReraiseTypeErrorWithFieldName(message_descriptor.name, field_name)
-
- init.__module__ = None
- init.__doc__ = None
- cls.__init__ = init
-
-
-def _GetFieldByName(message_descriptor, field_name):
- """Returns a field descriptor by field name.
-
- Args:
- message_descriptor: A Descriptor describing all fields in message.
- field_name: The name of the field to retrieve.
- Returns:
- The field descriptor associated with the field name.
- """
- try:
- return message_descriptor.fields_by_name[field_name]
- except KeyError:
- raise ValueError('Protocol message %s has no "%s" field.' %
- (message_descriptor.name, field_name))
-
-
-def _AddPropertiesForFields(descriptor, cls):
- """Adds properties for all fields in this protocol message type."""
- for field in descriptor.fields:
- _AddPropertiesForField(field, cls)
-
- if descriptor.is_extendable:
- # _ExtensionDict is just an adaptor with no state so we allocate a new one
- # every time it is accessed.
- cls.Extensions = property(lambda self: _ExtensionDict(self))
-
-
-def _AddPropertiesForField(field, cls):
- """Adds a public property for a protocol message field.
- Clients can use this property to get and (in the case
- of non-repeated scalar fields) directly set the value
- of a protocol message field.
-
- Args:
- field: A FieldDescriptor for this field.
- cls: The class we're constructing.
- """
- # Catch it if we add other types that we should
- # handle specially here.
- assert _FieldDescriptor.MAX_CPPTYPE == 10
-
- constant_name = field.name.upper() + "_FIELD_NUMBER"
- setattr(cls, constant_name, field.number)
-
- if field.label == _FieldDescriptor.LABEL_REPEATED:
- _AddPropertiesForRepeatedField(field, cls)
- elif field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
- _AddPropertiesForNonRepeatedCompositeField(field, cls)
- else:
- _AddPropertiesForNonRepeatedScalarField(field, cls)
-
-
-def _AddPropertiesForRepeatedField(field, cls):
- """Adds a public property for a "repeated" protocol message field. Clients
- can use this property to get the value of the field, which will be either a
- _RepeatedScalarFieldContainer or _RepeatedCompositeFieldContainer (see
- below).
-
- Note that when clients add values to these containers, we perform
- type-checking in the case of repeated scalar fields, and we also set any
- necessary "has" bits as a side-effect.
-
- Args:
- field: A FieldDescriptor for this field.
- cls: The class we're constructing.
- """
- proto_field_name = field.name
- property_name = _PropertyName(proto_field_name)
-
- def getter(self):
- field_value = self._fields.get(field)
- if field_value is None:
- # Construct a new object to represent this field.
- field_value = field._default_constructor(self)
-
- # Atomically check if another thread has preempted us and, if not, swap
- # in the new object we just created. If someone has preempted us, we
- # take that object and discard ours.
- # WARNING: We are relying on setdefault() being atomic. This is true
- # in CPython but we haven't investigated others. This warning appears
- # in several other locations in this file.
- field_value = self._fields.setdefault(field, field_value)
- return field_value
- getter.__module__ = None
- getter.__doc__ = 'Getter for %s.' % proto_field_name
-
- # We define a setter just so we can throw an exception with a more
- # helpful error message.
- def setter(self, new_value):
- raise AttributeError('Assignment not allowed to repeated field '
- '"%s" in protocol message object.' % proto_field_name)
-
- doc = 'Magic attribute generated for "%s" proto field.' % proto_field_name
- setattr(cls, property_name, property(getter, setter, doc=doc))
-
-
-def _AddPropertiesForNonRepeatedScalarField(field, cls):
- """Adds a public property for a nonrepeated, scalar protocol message field.
- Clients can use this property to get and directly set the value of the field.
- Note that when the client sets the value of a field by using this property,
- all necessary "has" bits are set as a side-effect, and we also perform
- type-checking.
-
- Args:
- field: A FieldDescriptor for this field.
- cls: The class we're constructing.
- """
- proto_field_name = field.name
- property_name = _PropertyName(proto_field_name)
- type_checker = type_checkers.GetTypeChecker(field)
- default_value = field.default_value
- valid_values = set()
- is_proto3 = field.containing_type.syntax == "proto3"
-
- def getter(self):
- # TODO(protobuf-team): This may be broken since there may not be
- # default_value. Combine with has_default_value somehow.
- return self._fields.get(field, default_value)
- getter.__module__ = None
- getter.__doc__ = 'Getter for %s.' % proto_field_name
-
- clear_when_set_to_default = is_proto3 and not field.containing_oneof
-
- def field_setter(self, new_value):
- # pylint: disable=protected-access
- # Testing the value for truthiness captures all of the proto3 defaults
- # (0, 0.0, enum 0, and False).
- new_value = type_checker.CheckValue(new_value)
- if clear_when_set_to_default and not new_value:
- self._fields.pop(field, None)
- else:
- self._fields[field] = new_value
- # Check _cached_byte_size_dirty inline to improve performance, since scalar
- # setters are called frequently.
- if not self._cached_byte_size_dirty:
- self._Modified()
-
- if field.containing_oneof:
- def setter(self, new_value):
- field_setter(self, new_value)
- self._UpdateOneofState(field)
- else:
- setter = field_setter
-
- setter.__module__ = None
- setter.__doc__ = 'Setter for %s.' % proto_field_name
-
- # Add a property to encapsulate the getter/setter.
- doc = 'Magic attribute generated for "%s" proto field.' % proto_field_name
- setattr(cls, property_name, property(getter, setter, doc=doc))
-
-
-def _AddPropertiesForNonRepeatedCompositeField(field, cls):
- """Adds a public property for a nonrepeated, composite protocol message field.
- A composite field is a "group" or "message" field.
-
- Clients can use this property to get the value of the field, but cannot
- assign to the property directly.
-
- Args:
- field: A FieldDescriptor for this field.
- cls: The class we're constructing.
- """
- # TODO(robinson): Remove duplication with similar method
- # for non-repeated scalars.
- proto_field_name = field.name
- property_name = _PropertyName(proto_field_name)
-
- def getter(self):
- field_value = self._fields.get(field)
- if field_value is None:
- # Construct a new object to represent this field.
- field_value = field._default_constructor(self)
-
- # Atomically check if another thread has preempted us and, if not, swap
- # in the new object we just created. If someone has preempted us, we
- # take that object and discard ours.
- # WARNING: We are relying on setdefault() being atomic. This is true
- # in CPython but we haven't investigated others. This warning appears
- # in several other locations in this file.
- field_value = self._fields.setdefault(field, field_value)
- return field_value
- getter.__module__ = None
- getter.__doc__ = 'Getter for %s.' % proto_field_name
-
- # We define a setter just so we can throw an exception with a more
- # helpful error message.
- def setter(self, new_value):
- raise AttributeError('Assignment not allowed to composite field '
- '"%s" in protocol message object.' % proto_field_name)
-
- # Add a property to encapsulate the getter.
- doc = 'Magic attribute generated for "%s" proto field.' % proto_field_name
- setattr(cls, property_name, property(getter, setter, doc=doc))
-
-
-def _AddPropertiesForExtensions(descriptor, cls):
- """Adds properties for all fields in this protocol message type."""
- extension_dict = descriptor.extensions_by_name
- for extension_name, extension_field in extension_dict.items():
- constant_name = extension_name.upper() + "_FIELD_NUMBER"
- setattr(cls, constant_name, extension_field.number)
-
-
-def _AddStaticMethods(cls):
- # TODO(robinson): This probably needs to be thread-safe(?)
- def RegisterExtension(extension_handle):
- extension_handle.containing_type = cls.DESCRIPTOR
- _AttachFieldHelpers(cls, extension_handle)
-
- # Try to insert our extension, failing if an extension with the same number
- # already exists.
- actual_handle = cls._extensions_by_number.setdefault(
- extension_handle.number, extension_handle)
- if actual_handle is not extension_handle:
- raise AssertionError(
- 'Extensions "%s" and "%s" both try to extend message type "%s" with '
- 'field number %d.' %
- (extension_handle.full_name, actual_handle.full_name,
- cls.DESCRIPTOR.full_name, extension_handle.number))
-
- cls._extensions_by_name[extension_handle.full_name] = extension_handle
-
- handle = extension_handle # avoid line wrapping
- if _IsMessageSetExtension(handle):
- # MessageSet extension. Also register under type name.
- cls._extensions_by_name[
- extension_handle.message_type.full_name] = extension_handle
-
- cls.RegisterExtension = staticmethod(RegisterExtension)
-
- def FromString(s):
- message = cls()
- message.MergeFromString(s)
- return message
- cls.FromString = staticmethod(FromString)
-
-
-def _IsPresent(item):
- """Given a (FieldDescriptor, value) tuple from _fields, return true if the
- value should be included in the list returned by ListFields()."""
-
- if item[0].label == _FieldDescriptor.LABEL_REPEATED:
- return bool(item[1])
- elif item[0].cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
- return item[1]._is_present_in_parent
- else:
- return True
-
-
-def _AddListFieldsMethod(message_descriptor, cls):
- """Helper for _AddMessageMethods()."""
-
- def ListFields(self):
- all_fields = [item for item in self._fields.items() if _IsPresent(item)]
- all_fields.sort(key = lambda item: item[0].number)
- return all_fields
-
- cls.ListFields = ListFields
-
-_Proto3HasError = 'Protocol message has no non-repeated submessage field "%s"'
-_Proto2HasError = 'Protocol message has no non-repeated field "%s"'
-
-def _AddHasFieldMethod(message_descriptor, cls):
- """Helper for _AddMessageMethods()."""
-
- is_proto3 = (message_descriptor.syntax == "proto3")
- error_msg = _Proto3HasError if is_proto3 else _Proto2HasError
-
- hassable_fields = {}
- for field in message_descriptor.fields:
- if field.label == _FieldDescriptor.LABEL_REPEATED:
- continue
- # For proto3, only submessages and fields inside a oneof have presence.
- if (is_proto3 and field.cpp_type != _FieldDescriptor.CPPTYPE_MESSAGE and
- not field.containing_oneof):
- continue
- hassable_fields[field.name] = field
-
- if not is_proto3:
- # Fields inside oneofs are never repeated (enforced by the compiler).
- for oneof in message_descriptor.oneofs:
- hassable_fields[oneof.name] = oneof
-
- def HasField(self, field_name):
- try:
- field = hassable_fields[field_name]
- except KeyError:
- raise ValueError(error_msg % field_name)
-
- if isinstance(field, descriptor_mod.OneofDescriptor):
- try:
- return HasField(self, self._oneofs[field].name)
- except KeyError:
- return False
- else:
- if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
- value = self._fields.get(field)
- return value is not None and value._is_present_in_parent
- else:
- return field in self._fields
-
- cls.HasField = HasField
-
-
-def _AddClearFieldMethod(message_descriptor, cls):
- """Helper for _AddMessageMethods()."""
- def ClearField(self, field_name):
- try:
- field = message_descriptor.fields_by_name[field_name]
- except KeyError:
- try:
- field = message_descriptor.oneofs_by_name[field_name]
- if field in self._oneofs:
- field = self._oneofs[field]
- else:
- return
- except KeyError:
- raise ValueError('Protocol message %s() has no "%s" field.' %
- (message_descriptor.name, field_name))
-
- if field in self._fields:
- # To match the C++ implementation, we need to invalidate iterators
- # for map fields when ClearField() happens.
- if hasattr(self._fields[field], 'InvalidateIterators'):
- self._fields[field].InvalidateIterators()
-
- # Note: If the field is a sub-message, its listener will still point
- # at us. That's fine, because the worst than can happen is that it
- # will call _Modified() and invalidate our byte size. Big deal.
- del self._fields[field]
-
- if self._oneofs.get(field.containing_oneof, None) is field:
- del self._oneofs[field.containing_oneof]
-
- # Always call _Modified() -- even if nothing was changed, this is
- # a mutating method, and thus calling it should cause the field to become
- # present in the parent message.
- self._Modified()
-
- cls.ClearField = ClearField
-
-
-def _AddClearExtensionMethod(cls):
- """Helper for _AddMessageMethods()."""
- def ClearExtension(self, extension_handle):
- _VerifyExtensionHandle(self, extension_handle)
-
- # Similar to ClearField(), above.
- if extension_handle in self._fields:
- del self._fields[extension_handle]
- self._Modified()
- cls.ClearExtension = ClearExtension
-
-
-def _AddHasExtensionMethod(cls):
- """Helper for _AddMessageMethods()."""
- def HasExtension(self, extension_handle):
- _VerifyExtensionHandle(self, extension_handle)
- if extension_handle.label == _FieldDescriptor.LABEL_REPEATED:
- raise KeyError('"%s" is repeated.' % extension_handle.full_name)
-
- if extension_handle.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
- value = self._fields.get(extension_handle)
- return value is not None and value._is_present_in_parent
- else:
- return extension_handle in self._fields
- cls.HasExtension = HasExtension
-
-def _InternalUnpackAny(msg):
- """Unpacks Any message and returns the unpacked message.
-
- This internal method is differnt from public Any Unpack method which takes
- the target message as argument. _InternalUnpackAny method does not have
- target message type and need to find the message type in descriptor pool.
-
- Args:
- msg: An Any message to be unpacked.
-
- Returns:
- The unpacked message.
- """
- # TODO(amauryfa): Don't use the factory of generated messages.
- # To make Any work with custom factories, use the message factory of the
- # parent message.
- # pylint: disable=g-import-not-at-top
- from google.protobuf import symbol_database
- factory = symbol_database.Default()
-
- type_url = msg.type_url
-
- if not type_url:
- return None
-
- # TODO(haberman): For now we just strip the hostname. Better logic will be
- # required.
- type_name = type_url.split('/')[-1]
- descriptor = factory.pool.FindMessageTypeByName(type_name)
-
- if descriptor is None:
- return None
-
- message_class = factory.GetPrototype(descriptor)
- message = message_class()
-
- message.ParseFromString(msg.value)
- return message
-
-
-def _AddEqualsMethod(message_descriptor, cls):
- """Helper for _AddMessageMethods()."""
- def __eq__(self, other):
- if (not isinstance(other, message_mod.Message) or
- other.DESCRIPTOR != self.DESCRIPTOR):
- return False
-
- if self is other:
- return True
-
- if self.DESCRIPTOR.full_name == _AnyFullTypeName:
- any_a = _InternalUnpackAny(self)
- any_b = _InternalUnpackAny(other)
- if any_a and any_b:
- return any_a == any_b
-
- if not self.ListFields() == other.ListFields():
- return False
-
- # Sort unknown fields because their order shouldn't affect equality test.
- unknown_fields = list(self._unknown_fields)
- unknown_fields.sort()
- other_unknown_fields = list(other._unknown_fields)
- other_unknown_fields.sort()
-
- return unknown_fields == other_unknown_fields
-
- cls.__eq__ = __eq__
-
-
-def _AddStrMethod(message_descriptor, cls):
- """Helper for _AddMessageMethods()."""
- def __str__(self):
- return text_format.MessageToString(self)
- cls.__str__ = __str__
-
-
-def _AddReprMethod(message_descriptor, cls):
- """Helper for _AddMessageMethods()."""
- def __repr__(self):
- return text_format.MessageToString(self)
- cls.__repr__ = __repr__
-
-
-def _AddUnicodeMethod(unused_message_descriptor, cls):
- """Helper for _AddMessageMethods()."""
-
- def __unicode__(self):
- return text_format.MessageToString(self, as_utf8=True).decode('utf-8')
- cls.__unicode__ = __unicode__
-
-
-def _BytesForNonRepeatedElement(value, field_number, field_type):
- """Returns the number of bytes needed to serialize a non-repeated element.
- The returned byte count includes space for tag information and any
- other additional space associated with serializing value.
-
- Args:
- value: Value we're serializing.
- field_number: Field number of this value. (Since the field number
- is stored as part of a varint-encoded tag, this has an impact
- on the total bytes required to serialize the value).
- field_type: The type of the field. One of the TYPE_* constants
- within FieldDescriptor.
- """
- try:
- fn = type_checkers.TYPE_TO_BYTE_SIZE_FN[field_type]
- return fn(field_number, value)
- except KeyError:
- raise message_mod.EncodeError('Unrecognized field type: %d' % field_type)
-
-
-def _AddByteSizeMethod(message_descriptor, cls):
- """Helper for _AddMessageMethods()."""
-
- def ByteSize(self):
- if not self._cached_byte_size_dirty:
- return self._cached_byte_size
-
- size = 0
- for field_descriptor, field_value in self.ListFields():
- size += field_descriptor._sizer(field_value)
-
- for tag_bytes, value_bytes in self._unknown_fields:
- size += len(tag_bytes) + len(value_bytes)
-
- self._cached_byte_size = size
- self._cached_byte_size_dirty = False
- self._listener_for_children.dirty = False
- return size
-
- cls.ByteSize = ByteSize
-
-
-def _AddSerializeToStringMethod(message_descriptor, cls):
- """Helper for _AddMessageMethods()."""
-
- def SerializeToString(self):
- # Check if the message has all of its required fields set.
- errors = []
- if not self.IsInitialized():
- raise message_mod.EncodeError(
- 'Message %s is missing required fields: %s' % (
- self.DESCRIPTOR.full_name, ','.join(self.FindInitializationErrors())))
- return self.SerializePartialToString()
- cls.SerializeToString = SerializeToString
-
-
-def _AddSerializePartialToStringMethod(message_descriptor, cls):
- """Helper for _AddMessageMethods()."""
-
- def SerializePartialToString(self):
- out = BytesIO()
- self._InternalSerialize(out.write)
- return out.getvalue()
- cls.SerializePartialToString = SerializePartialToString
-
- def InternalSerialize(self, write_bytes):
- for field_descriptor, field_value in self.ListFields():
- field_descriptor._encoder(write_bytes, field_value)
- for tag_bytes, value_bytes in self._unknown_fields:
- write_bytes(tag_bytes)
- write_bytes(value_bytes)
- cls._InternalSerialize = InternalSerialize
-
-
-def _AddMergeFromStringMethod(message_descriptor, cls):
- """Helper for _AddMessageMethods()."""
- def MergeFromString(self, serialized):
- length = len(serialized)
- try:
- if self._InternalParse(serialized, 0, length) != length:
- # The only reason _InternalParse would return early is if it
- # encountered an end-group tag.
- raise message_mod.DecodeError('Unexpected end-group tag.')
- except (IndexError, TypeError):
- # Now ord(buf[p:p+1]) == ord('') gets TypeError.
- raise message_mod.DecodeError('Truncated message.')
- except struct.error as e:
- raise message_mod.DecodeError(e)
- return length # Return this for legacy reasons.
- cls.MergeFromString = MergeFromString
-
- local_ReadTag = decoder.ReadTag
- local_SkipField = decoder.SkipField
- decoders_by_tag = cls._decoders_by_tag
- is_proto3 = message_descriptor.syntax == "proto3"
-
- def InternalParse(self, buffer, pos, end):
- self._Modified()
- field_dict = self._fields
- unknown_field_list = self._unknown_fields
- while pos != end:
- (tag_bytes, new_pos) = local_ReadTag(buffer, pos)
- field_decoder, field_desc = decoders_by_tag.get(tag_bytes, (None, None))
- if field_decoder is None:
- value_start_pos = new_pos
- new_pos = local_SkipField(buffer, new_pos, end, tag_bytes)
- if new_pos == -1:
- return pos
- if not is_proto3:
- if not unknown_field_list:
- unknown_field_list = self._unknown_fields = []
- unknown_field_list.append(
- (tag_bytes, buffer[value_start_pos:new_pos]))
- pos = new_pos
- else:
- pos = field_decoder(buffer, new_pos, end, self, field_dict)
- if field_desc:
- self._UpdateOneofState(field_desc)
- return pos
- cls._InternalParse = InternalParse
-
-
-def _AddIsInitializedMethod(message_descriptor, cls):
- """Adds the IsInitialized and FindInitializationError methods to the
- protocol message class."""
-
- required_fields = [field for field in message_descriptor.fields
- if field.label == _FieldDescriptor.LABEL_REQUIRED]
-
- def IsInitialized(self, errors=None):
- """Checks if all required fields of a message are set.
-
- Args:
- errors: A list which, if provided, will be populated with the field
- paths of all missing required fields.
-
- Returns:
- True iff the specified message has all required fields set.
- """
-
- # Performance is critical so we avoid HasField() and ListFields().
-
- for field in required_fields:
- if (field not in self._fields or
- (field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE and
- not self._fields[field]._is_present_in_parent)):
- if errors is not None:
- errors.extend(self.FindInitializationErrors())
- return False
-
- for field, value in list(self._fields.items()): # dict can change size!
- if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
- if field.label == _FieldDescriptor.LABEL_REPEATED:
- if (field.message_type.has_options and
- field.message_type.GetOptions().map_entry):
- continue
- for element in value:
- if not element.IsInitialized():
- if errors is not None:
- errors.extend(self.FindInitializationErrors())
- return False
- elif value._is_present_in_parent and not value.IsInitialized():
- if errors is not None:
- errors.extend(self.FindInitializationErrors())
- return False
-
- return True
-
- cls.IsInitialized = IsInitialized
-
- def FindInitializationErrors(self):
- """Finds required fields which are not initialized.
-
- Returns:
- A list of strings. Each string is a path to an uninitialized field from
- the top-level message, e.g. "foo.bar[5].baz".
- """
-
- errors = [] # simplify things
-
- for field in required_fields:
- if not self.HasField(field.name):
- errors.append(field.name)
-
- for field, value in self.ListFields():
- if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
- if field.is_extension:
- name = "(%s)" % field.full_name
- else:
- name = field.name
-
- if _IsMapField(field):
- if _IsMessageMapField(field):
- for key in value:
- element = value[key]
- prefix = "%s[%s]." % (name, key)
- sub_errors = element.FindInitializationErrors()
- errors += [prefix + error for error in sub_errors]
- else:
- # ScalarMaps can't have any initialization errors.
- pass
- elif field.label == _FieldDescriptor.LABEL_REPEATED:
- for i in range(len(value)):
- element = value[i]
- prefix = "%s[%d]." % (name, i)
- sub_errors = element.FindInitializationErrors()
- errors += [prefix + error for error in sub_errors]
- else:
- prefix = name + "."
- sub_errors = value.FindInitializationErrors()
- errors += [prefix + error for error in sub_errors]
-
- return errors
-
- cls.FindInitializationErrors = FindInitializationErrors
-
-
-def _AddMergeFromMethod(cls):
- LABEL_REPEATED = _FieldDescriptor.LABEL_REPEATED
- CPPTYPE_MESSAGE = _FieldDescriptor.CPPTYPE_MESSAGE
-
- def MergeFrom(self, msg):
- if not isinstance(msg, cls):
- raise TypeError(
- "Parameter to MergeFrom() must be instance of same class: "
- "expected %s got %s." % (cls.__name__, type(msg).__name__))
-
- assert msg is not self
- self._Modified()
-
- fields = self._fields
-
- for field, value in msg._fields.items():
- if field.label == LABEL_REPEATED:
- field_value = fields.get(field)
- if field_value is None:
- # Construct a new object to represent this field.
- field_value = field._default_constructor(self)
- fields[field] = field_value
- field_value.MergeFrom(value)
- elif field.cpp_type == CPPTYPE_MESSAGE:
- if value._is_present_in_parent:
- field_value = fields.get(field)
- if field_value is None:
- # Construct a new object to represent this field.
- field_value = field._default_constructor(self)
- fields[field] = field_value
- field_value.MergeFrom(value)
- else:
- self._fields[field] = value
- if field.containing_oneof:
- self._UpdateOneofState(field)
-
- if msg._unknown_fields:
- if not self._unknown_fields:
- self._unknown_fields = []
- self._unknown_fields.extend(msg._unknown_fields)
-
- cls.MergeFrom = MergeFrom
-
-
-def _AddWhichOneofMethod(message_descriptor, cls):
- def WhichOneof(self, oneof_name):
- """Returns the name of the currently set field inside a oneof, or None."""
- try:
- field = message_descriptor.oneofs_by_name[oneof_name]
- except KeyError:
- raise ValueError(
- 'Protocol message has no oneof "%s" field.' % oneof_name)
-
- nested_field = self._oneofs.get(field, None)
- if nested_field is not None and self.HasField(nested_field.name):
- return nested_field.name
- else:
- return None
-
- cls.WhichOneof = WhichOneof
-
-
-def _Clear(self):
- # Clear fields.
- self._fields = {}
- self._unknown_fields = ()
- self._oneofs = {}
- self._Modified()
-
-
-def _DiscardUnknownFields(self):
- self._unknown_fields = []
- for field, value in self.ListFields():
- if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
- if field.label == _FieldDescriptor.LABEL_REPEATED:
- for sub_message in value:
- sub_message.DiscardUnknownFields()
- else:
- value.DiscardUnknownFields()
-
-
-def _SetListener(self, listener):
- if listener is None:
- self._listener = message_listener_mod.NullMessageListener()
- else:
- self._listener = listener
-
-
-def _AddMessageMethods(message_descriptor, cls):
- """Adds implementations of all Message methods to cls."""
- _AddListFieldsMethod(message_descriptor, cls)
- _AddHasFieldMethod(message_descriptor, cls)
- _AddClearFieldMethod(message_descriptor, cls)
- if message_descriptor.is_extendable:
- _AddClearExtensionMethod(cls)
- _AddHasExtensionMethod(cls)
- _AddEqualsMethod(message_descriptor, cls)
- _AddStrMethod(message_descriptor, cls)
- _AddReprMethod(message_descriptor, cls)
- _AddUnicodeMethod(message_descriptor, cls)
- _AddByteSizeMethod(message_descriptor, cls)
- _AddSerializeToStringMethod(message_descriptor, cls)
- _AddSerializePartialToStringMethod(message_descriptor, cls)
- _AddMergeFromStringMethod(message_descriptor, cls)
- _AddIsInitializedMethod(message_descriptor, cls)
- _AddMergeFromMethod(cls)
- _AddWhichOneofMethod(message_descriptor, cls)
- # Adds methods which do not depend on cls.
- cls.Clear = _Clear
- cls.DiscardUnknownFields = _DiscardUnknownFields
- cls._SetListener = _SetListener
-
-
-def _AddPrivateHelperMethods(message_descriptor, cls):
- """Adds implementation of private helper methods to cls."""
-
- def Modified(self):
- """Sets the _cached_byte_size_dirty bit to true,
- and propagates this to our listener iff this was a state change.
- """
-
- # Note: Some callers check _cached_byte_size_dirty before calling
- # _Modified() as an extra optimization. So, if this method is ever
- # changed such that it does stuff even when _cached_byte_size_dirty is
- # already true, the callers need to be updated.
- if not self._cached_byte_size_dirty:
- self._cached_byte_size_dirty = True
- self._listener_for_children.dirty = True
- self._is_present_in_parent = True
- self._listener.Modified()
-
- def _UpdateOneofState(self, field):
- """Sets field as the active field in its containing oneof.
-
- Will also delete currently active field in the oneof, if it is different
- from the argument. Does not mark the message as modified.
- """
- other_field = self._oneofs.setdefault(field.containing_oneof, field)
- if other_field is not field:
- del self._fields[other_field]
- self._oneofs[field.containing_oneof] = field
-
- cls._Modified = Modified
- cls.SetInParent = Modified
- cls._UpdateOneofState = _UpdateOneofState
-
-
-class _Listener(object):
-
- """MessageListener implementation that a parent message registers with its
- child message.
-
- In order to support semantics like:
-
- foo.bar.baz.qux = 23
- assert foo.HasField('bar')
-
- ...child objects must have back references to their parents.
- This helper class is at the heart of this support.
- """
-
- def __init__(self, parent_message):
- """Args:
- parent_message: The message whose _Modified() method we should call when
- we receive Modified() messages.
- """
- # This listener establishes a back reference from a child (contained) object
- # to its parent (containing) object. We make this a weak reference to avoid
- # creating cyclic garbage when the client finishes with the 'parent' object
- # in the tree.
- if isinstance(parent_message, weakref.ProxyType):
- self._parent_message_weakref = parent_message
- else:
- self._parent_message_weakref = weakref.proxy(parent_message)
-
- # As an optimization, we also indicate directly on the listener whether
- # or not the parent message is dirty. This way we can avoid traversing
- # up the tree in the common case.
- self.dirty = False
-
- def Modified(self):
- if self.dirty:
- return
- try:
- # Propagate the signal to our parents iff this is the first field set.
- self._parent_message_weakref._Modified()
- except ReferenceError:
- # We can get here if a client has kept a reference to a child object,
- # and is now setting a field on it, but the child's parent has been
- # garbage-collected. This is not an error.
- pass
-
-
-class _OneofListener(_Listener):
- """Special listener implementation for setting composite oneof fields."""
-
- def __init__(self, parent_message, field):
- """Args:
- parent_message: The message whose _Modified() method we should call when
- we receive Modified() messages.
- field: The descriptor of the field being set in the parent message.
- """
- super(_OneofListener, self).__init__(parent_message)
- self._field = field
-
- def Modified(self):
- """Also updates the state of the containing oneof in the parent message."""
- try:
- self._parent_message_weakref._UpdateOneofState(self._field)
- super(_OneofListener, self).Modified()
- except ReferenceError:
- pass
-
-
-# TODO(robinson): Move elsewhere? This file is getting pretty ridiculous...
-# TODO(robinson): Unify error handling of "unknown extension" crap.
-# TODO(robinson): Support iteritems()-style iteration over all
-# extensions with the "has" bits turned on?
-class _ExtensionDict(object):
-
- """Dict-like container for supporting an indexable "Extensions"
- field on proto instances.
-
- Note that in all cases we expect extension handles to be
- FieldDescriptors.
- """
-
- def __init__(self, extended_message):
- """extended_message: Message instance for which we are the Extensions dict.
- """
-
- self._extended_message = extended_message
-
- def __getitem__(self, extension_handle):
- """Returns the current value of the given extension handle."""
-
- _VerifyExtensionHandle(self._extended_message, extension_handle)
-
- result = self._extended_message._fields.get(extension_handle)
- if result is not None:
- return result
-
- if extension_handle.label == _FieldDescriptor.LABEL_REPEATED:
- result = extension_handle._default_constructor(self._extended_message)
- elif extension_handle.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
- result = extension_handle.message_type._concrete_class()
- try:
- result._SetListener(self._extended_message._listener_for_children)
- except ReferenceError:
- pass
- else:
- # Singular scalar -- just return the default without inserting into the
- # dict.
- return extension_handle.default_value
-
- # Atomically check if another thread has preempted us and, if not, swap
- # in the new object we just created. If someone has preempted us, we
- # take that object and discard ours.
- # WARNING: We are relying on setdefault() being atomic. This is true
- # in CPython but we haven't investigated others. This warning appears
- # in several other locations in this file.
- result = self._extended_message._fields.setdefault(
- extension_handle, result)
-
- return result
-
- def __eq__(self, other):
- if not isinstance(other, self.__class__):
- return False
-
- my_fields = self._extended_message.ListFields()
- other_fields = other._extended_message.ListFields()
-
- # Get rid of non-extension fields.
- my_fields = [ field for field in my_fields if field.is_extension ]
- other_fields = [ field for field in other_fields if field.is_extension ]
-
- return my_fields == other_fields
-
- def __ne__(self, other):
- return not self == other
-
- def __hash__(self):
- raise TypeError('unhashable object')
-
- # Note that this is only meaningful for non-repeated, scalar extension
- # fields. Note also that we may have to call _Modified() when we do
- # successfully set a field this way, to set any necssary "has" bits in the
- # ancestors of the extended message.
- def __setitem__(self, extension_handle, value):
- """If extension_handle specifies a non-repeated, scalar extension
- field, sets the value of that field.
- """
-
- _VerifyExtensionHandle(self._extended_message, extension_handle)
-
- if (extension_handle.label == _FieldDescriptor.LABEL_REPEATED or
- extension_handle.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE):
- raise TypeError(
- 'Cannot assign to extension "%s" because it is a repeated or '
- 'composite type.' % extension_handle.full_name)
-
- # It's slightly wasteful to lookup the type checker each time,
- # but we expect this to be a vanishingly uncommon case anyway.
- type_checker = type_checkers.GetTypeChecker(extension_handle)
- # pylint: disable=protected-access
- self._extended_message._fields[extension_handle] = (
- type_checker.CheckValue(value))
- self._extended_message._Modified()
-
- def _FindExtensionByName(self, name):
- """Tries to find a known extension with the specified name.
-
- Args:
- name: Extension full name.
-
- Returns:
- Extension field descriptor.
- """
- return self._extended_message._extensions_by_name.get(name, None)
-
- def _FindExtensionByNumber(self, number):
- """Tries to find a known extension with the field number.
-
- Args:
- number: Extension field number.
-
- Returns:
- Extension field descriptor.
- """
- return self._extended_message._extensions_by_number.get(number, None)