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Diffstat (limited to 'python/google/protobuf/internal/cpp_message.py')
-rwxr-xr-x | python/google/protobuf/internal/cpp_message.py | 663 |
1 files changed, 663 insertions, 0 deletions
diff --git a/python/google/protobuf/internal/cpp_message.py b/python/google/protobuf/internal/cpp_message.py new file mode 100755 index 0000000..0313cb0 --- /dev/null +++ b/python/google/protobuf/internal/cpp_message.py @@ -0,0 +1,663 @@ +# 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. + +"""Contains helper functions used to create protocol message classes from +Descriptor objects at runtime backed by the protocol buffer C++ API. +""" + +__author__ = 'petar@google.com (Petar Petrov)' + +import copy_reg +import operator +from google.protobuf.internal import _net_proto2___python +from google.protobuf.internal import enum_type_wrapper +from google.protobuf import message + + +_LABEL_REPEATED = _net_proto2___python.LABEL_REPEATED +_LABEL_OPTIONAL = _net_proto2___python.LABEL_OPTIONAL +_CPPTYPE_MESSAGE = _net_proto2___python.CPPTYPE_MESSAGE +_TYPE_MESSAGE = _net_proto2___python.TYPE_MESSAGE + + +def GetDescriptorPool(): + """Creates a new DescriptorPool C++ object.""" + return _net_proto2___python.NewCDescriptorPool() + + +_pool = GetDescriptorPool() + + +def GetFieldDescriptor(full_field_name): + """Searches for a field descriptor given a full field name.""" + return _pool.FindFieldByName(full_field_name) + + +def BuildFile(content): + """Registers a new proto file in the underlying C++ descriptor pool.""" + _net_proto2___python.BuildFile(content) + + +def GetExtensionDescriptor(full_extension_name): + """Searches for extension descriptor given a full field name.""" + return _pool.FindExtensionByName(full_extension_name) + + +def NewCMessage(full_message_name): + """Creates a new C++ protocol message by its name.""" + return _net_proto2___python.NewCMessage(full_message_name) + + +def ScalarProperty(cdescriptor): + """Returns a scalar property for the given descriptor.""" + + def Getter(self): + return self._cmsg.GetScalar(cdescriptor) + + def Setter(self, value): + self._cmsg.SetScalar(cdescriptor, value) + + return property(Getter, Setter) + + +def CompositeProperty(cdescriptor, message_type): + """Returns a Python property the given composite field.""" + + def Getter(self): + sub_message = self._composite_fields.get(cdescriptor.name, None) + if sub_message is None: + cmessage = self._cmsg.NewSubMessage(cdescriptor) + sub_message = message_type._concrete_class(__cmessage=cmessage) + self._composite_fields[cdescriptor.name] = sub_message + return sub_message + + return property(Getter) + + +class RepeatedScalarContainer(object): + """Container for repeated scalar fields.""" + + __slots__ = ['_message', '_cfield_descriptor', '_cmsg'] + + def __init__(self, msg, cfield_descriptor): + self._message = msg + self._cmsg = msg._cmsg + self._cfield_descriptor = cfield_descriptor + + def append(self, value): + self._cmsg.AddRepeatedScalar( + self._cfield_descriptor, value) + + def extend(self, sequence): + for element in sequence: + self.append(element) + + def insert(self, key, value): + values = self[slice(None, None, None)] + values.insert(key, value) + self._cmsg.AssignRepeatedScalar(self._cfield_descriptor, values) + + def remove(self, value): + values = self[slice(None, None, None)] + values.remove(value) + self._cmsg.AssignRepeatedScalar(self._cfield_descriptor, values) + + def __setitem__(self, key, value): + values = self[slice(None, None, None)] + values[key] = value + self._cmsg.AssignRepeatedScalar(self._cfield_descriptor, values) + + def __getitem__(self, key): + return self._cmsg.GetRepeatedScalar(self._cfield_descriptor, key) + + def __delitem__(self, key): + self._cmsg.DeleteRepeatedField(self._cfield_descriptor, key) + + def __len__(self): + return len(self[slice(None, None, None)]) + + def __eq__(self, other): + if self is other: + return True + if not operator.isSequenceType(other): + raise TypeError( + 'Can only compare repeated scalar fields against sequences.') + # We are presumably comparing against some other sequence type. + return other == self[slice(None, None, None)] + + def __ne__(self, other): + return not self == other + + def __hash__(self): + raise TypeError('unhashable object') + + def sort(self, *args, **kwargs): + # Maintain compatibility with the previous interface. + if 'sort_function' in kwargs: + kwargs['cmp'] = kwargs.pop('sort_function') + self._cmsg.AssignRepeatedScalar(self._cfield_descriptor, + sorted(self, *args, **kwargs)) + + +def RepeatedScalarProperty(cdescriptor): + """Returns a Python property the given repeated scalar field.""" + + def Getter(self): + container = self._composite_fields.get(cdescriptor.name, None) + if container is None: + container = RepeatedScalarContainer(self, cdescriptor) + self._composite_fields[cdescriptor.name] = container + return container + + def Setter(self, new_value): + raise AttributeError('Assignment not allowed to repeated field ' + '"%s" in protocol message object.' % cdescriptor.name) + + doc = 'Magic attribute generated for "%s" proto field.' % cdescriptor.name + return property(Getter, Setter, doc=doc) + + +class RepeatedCompositeContainer(object): + """Container for repeated composite fields.""" + + __slots__ = ['_message', '_subclass', '_cfield_descriptor', '_cmsg'] + + def __init__(self, msg, cfield_descriptor, subclass): + self._message = msg + self._cmsg = msg._cmsg + self._subclass = subclass + self._cfield_descriptor = cfield_descriptor + + def add(self, **kwargs): + cmessage = self._cmsg.AddMessage(self._cfield_descriptor) + return self._subclass(__cmessage=cmessage, __owner=self._message, **kwargs) + + def extend(self, elem_seq): + """Extends by appending the given sequence of elements of the same type + as this one, copying each individual message. + """ + for message in elem_seq: + self.add().MergeFrom(message) + + def remove(self, value): + # TODO(protocol-devel): This is inefficient as it needs to generate a + # message pointer for each message only to do index(). Move this to a C++ + # extension function. + self.__delitem__(self[slice(None, None, None)].index(value)) + + def MergeFrom(self, other): + for message in other[:]: + self.add().MergeFrom(message) + + def __getitem__(self, key): + cmessages = self._cmsg.GetRepeatedMessage( + self._cfield_descriptor, key) + subclass = self._subclass + if not isinstance(cmessages, list): + return subclass(__cmessage=cmessages, __owner=self._message) + + return [subclass(__cmessage=m, __owner=self._message) for m in cmessages] + + def __delitem__(self, key): + self._cmsg.DeleteRepeatedField( + self._cfield_descriptor, key) + + def __len__(self): + return self._cmsg.FieldLength(self._cfield_descriptor) + + def __eq__(self, other): + """Compares the current instance with another one.""" + if self is other: + return True + if not isinstance(other, self.__class__): + raise TypeError('Can only compare repeated composite fields against ' + 'other repeated composite fields.') + messages = self[slice(None, None, None)] + other_messages = other[slice(None, None, None)] + return messages == other_messages + + def __hash__(self): + raise TypeError('unhashable object') + + def sort(self, cmp=None, key=None, reverse=False, **kwargs): + # Maintain compatibility with the old interface. + if cmp is None and 'sort_function' in kwargs: + cmp = kwargs.pop('sort_function') + + # The cmp function, if provided, is passed the results of the key function, + # so we only need to wrap one of them. + if key is None: + index_key = self.__getitem__ + else: + index_key = lambda i: key(self[i]) + + # Sort the list of current indexes by the underlying object. + indexes = range(len(self)) + indexes.sort(cmp=cmp, key=index_key, reverse=reverse) + + # Apply the transposition. + for dest, src in enumerate(indexes): + if dest == src: + continue + self._cmsg.SwapRepeatedFieldElements(self._cfield_descriptor, dest, src) + # Don't swap the same value twice. + indexes[src] = src + + +def RepeatedCompositeProperty(cdescriptor, message_type): + """Returns a Python property for the given repeated composite field.""" + + def Getter(self): + container = self._composite_fields.get(cdescriptor.name, None) + if container is None: + container = RepeatedCompositeContainer( + self, cdescriptor, message_type._concrete_class) + self._composite_fields[cdescriptor.name] = container + return container + + def Setter(self, new_value): + raise AttributeError('Assignment not allowed to repeated field ' + '"%s" in protocol message object.' % cdescriptor.name) + + doc = 'Magic attribute generated for "%s" proto field.' % cdescriptor.name + return property(Getter, Setter, doc=doc) + + +class ExtensionDict(object): + """Extension dictionary added to each protocol message.""" + + def __init__(self, msg): + self._message = msg + self._cmsg = msg._cmsg + self._values = {} + + def __setitem__(self, extension, value): + from google.protobuf import descriptor + if not isinstance(extension, descriptor.FieldDescriptor): + raise KeyError('Bad extension %r.' % (extension,)) + cdescriptor = extension._cdescriptor + if (cdescriptor.label != _LABEL_OPTIONAL or + cdescriptor.cpp_type == _CPPTYPE_MESSAGE): + raise TypeError('Extension %r is repeated and/or a composite type.' % ( + extension.full_name,)) + self._cmsg.SetScalar(cdescriptor, value) + self._values[extension] = value + + def __getitem__(self, extension): + from google.protobuf import descriptor + if not isinstance(extension, descriptor.FieldDescriptor): + raise KeyError('Bad extension %r.' % (extension,)) + + cdescriptor = extension._cdescriptor + if (cdescriptor.label != _LABEL_REPEATED and + cdescriptor.cpp_type != _CPPTYPE_MESSAGE): + return self._cmsg.GetScalar(cdescriptor) + + ext = self._values.get(extension, None) + if ext is not None: + return ext + + ext = self._CreateNewHandle(extension) + self._values[extension] = ext + return ext + + def ClearExtension(self, extension): + from google.protobuf import descriptor + if not isinstance(extension, descriptor.FieldDescriptor): + raise KeyError('Bad extension %r.' % (extension,)) + self._cmsg.ClearFieldByDescriptor(extension._cdescriptor) + if extension in self._values: + del self._values[extension] + + def HasExtension(self, extension): + from google.protobuf import descriptor + if not isinstance(extension, descriptor.FieldDescriptor): + raise KeyError('Bad extension %r.' % (extension,)) + return self._cmsg.HasFieldByDescriptor(extension._cdescriptor) + + 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._message._extensions_by_name.get(name, None) + + def _CreateNewHandle(self, extension): + cdescriptor = extension._cdescriptor + if (cdescriptor.label != _LABEL_REPEATED and + cdescriptor.cpp_type == _CPPTYPE_MESSAGE): + cmessage = self._cmsg.NewSubMessage(cdescriptor) + return extension.message_type._concrete_class(__cmessage=cmessage) + + if cdescriptor.label == _LABEL_REPEATED: + if cdescriptor.cpp_type == _CPPTYPE_MESSAGE: + return RepeatedCompositeContainer( + self._message, cdescriptor, extension.message_type._concrete_class) + else: + return RepeatedScalarContainer(self._message, cdescriptor) + # This shouldn't happen! + assert False + return None + + +def NewMessage(bases, message_descriptor, dictionary): + """Creates a new protocol message *class*.""" + _AddClassAttributesForNestedExtensions(message_descriptor, dictionary) + _AddEnumValues(message_descriptor, dictionary) + _AddDescriptors(message_descriptor, dictionary) + return bases + + +def InitMessage(message_descriptor, cls): + """Constructs a new message instance (called before instance's __init__).""" + cls._extensions_by_name = {} + _AddInitMethod(message_descriptor, cls) + _AddMessageMethods(message_descriptor, cls) + _AddPropertiesForExtensions(message_descriptor, cls) + copy_reg.pickle(cls, lambda obj: (cls, (), obj.__getstate__())) + + +def _AddDescriptors(message_descriptor, dictionary): + """Sets up a new protocol message class dictionary. + + Args: + message_descriptor: A Descriptor instance describing this message type. + dictionary: Class dictionary to which we'll add a '__slots__' entry. + """ + dictionary['__descriptors'] = {} + for field in message_descriptor.fields: + dictionary['__descriptors'][field.name] = GetFieldDescriptor( + field.full_name) + + dictionary['__slots__'] = list(dictionary['__descriptors'].iterkeys()) + [ + '_cmsg', '_owner', '_composite_fields', 'Extensions', '_HACK_REFCOUNTS'] + + +def _AddEnumValues(message_descriptor, dictionary): + """Sets class-level attributes for all enum fields defined in this message. + + Args: + message_descriptor: Descriptor object for this message type. + dictionary: Class dictionary that should be populated. + """ + for enum_type in message_descriptor.enum_types: + dictionary[enum_type.name] = enum_type_wrapper.EnumTypeWrapper(enum_type) + for enum_value in enum_type.values: + dictionary[enum_value.name] = enum_value.number + + +def _AddClassAttributesForNestedExtensions(message_descriptor, dictionary): + """Adds class attributes for the nested extensions.""" + extension_dict = message_descriptor.extensions_by_name + for extension_name, extension_field in extension_dict.iteritems(): + assert extension_name not in dictionary + dictionary[extension_name] = extension_field + + +def _AddInitMethod(message_descriptor, cls): + """Adds an __init__ method to cls.""" + + # Create and attach message field properties to the message class. + # This can be done just once per message class, since property setters and + # getters are passed the message instance. + # This makes message instantiation extremely fast, and at the same time it + # doesn't require the creation of property objects for each message instance, + # which saves a lot of memory. + for field in message_descriptor.fields: + field_cdescriptor = cls.__descriptors[field.name] + if field.label == _LABEL_REPEATED: + if field.cpp_type == _CPPTYPE_MESSAGE: + value = RepeatedCompositeProperty(field_cdescriptor, field.message_type) + else: + value = RepeatedScalarProperty(field_cdescriptor) + elif field.cpp_type == _CPPTYPE_MESSAGE: + value = CompositeProperty(field_cdescriptor, field.message_type) + else: + value = ScalarProperty(field_cdescriptor) + setattr(cls, field.name, value) + + # Attach a constant with the field number. + constant_name = field.name.upper() + '_FIELD_NUMBER' + setattr(cls, constant_name, field.number) + + def Init(self, **kwargs): + """Message constructor.""" + cmessage = kwargs.pop('__cmessage', None) + if cmessage: + self._cmsg = cmessage + else: + self._cmsg = NewCMessage(message_descriptor.full_name) + + # Keep a reference to the owner, as the owner keeps a reference to the + # underlying protocol buffer message. + owner = kwargs.pop('__owner', None) + if owner: + self._owner = owner + + if message_descriptor.is_extendable: + self.Extensions = ExtensionDict(self) + else: + # Reference counting in the C++ code is broken and depends on + # the Extensions reference to keep this object alive during unit + # tests (see b/4856052). Remove this once b/4945904 is fixed. + self._HACK_REFCOUNTS = self + self._composite_fields = {} + + for field_name, field_value in kwargs.iteritems(): + field_cdescriptor = self.__descriptors.get(field_name, None) + if not field_cdescriptor: + raise ValueError('Protocol message has no "%s" field.' % field_name) + if field_cdescriptor.label == _LABEL_REPEATED: + if field_cdescriptor.cpp_type == _CPPTYPE_MESSAGE: + field_name = getattr(self, field_name) + for val in field_value: + field_name.add().MergeFrom(val) + else: + getattr(self, field_name).extend(field_value) + elif field_cdescriptor.cpp_type == _CPPTYPE_MESSAGE: + getattr(self, field_name).MergeFrom(field_value) + else: + setattr(self, field_name, field_value) + + Init.__module__ = None + Init.__doc__ = None + cls.__init__ = Init + + +def _IsMessageSetExtension(field): + """Checks if a field is a message set extension.""" + return (field.is_extension and + field.containing_type.has_options and + field.containing_type.GetOptions().message_set_wire_format and + field.type == _TYPE_MESSAGE and + field.message_type == field.extension_scope and + field.label == _LABEL_OPTIONAL) + + +def _AddMessageMethods(message_descriptor, cls): + """Adds the methods to a protocol message class.""" + if message_descriptor.is_extendable: + + def ClearExtension(self, extension): + self.Extensions.ClearExtension(extension) + + def HasExtension(self, extension): + return self.Extensions.HasExtension(extension) + + def HasField(self, field_name): + return self._cmsg.HasField(field_name) + + def ClearField(self, field_name): + child_cmessage = None + if field_name in self._composite_fields: + child_field = self._composite_fields[field_name] + del self._composite_fields[field_name] + + child_cdescriptor = self.__descriptors[field_name] + # TODO(anuraag): Support clearing repeated message fields as well. + if (child_cdescriptor.label != _LABEL_REPEATED and + child_cdescriptor.cpp_type == _CPPTYPE_MESSAGE): + child_field._owner = None + child_cmessage = child_field._cmsg + + if child_cmessage is not None: + self._cmsg.ClearField(field_name, child_cmessage) + else: + self._cmsg.ClearField(field_name) + + def Clear(self): + cmessages_to_release = [] + for field_name, child_field in self._composite_fields.iteritems(): + child_cdescriptor = self.__descriptors[field_name] + # TODO(anuraag): Support clearing repeated message fields as well. + if (child_cdescriptor.label != _LABEL_REPEATED and + child_cdescriptor.cpp_type == _CPPTYPE_MESSAGE): + child_field._owner = None + cmessages_to_release.append((child_cdescriptor, child_field._cmsg)) + self._composite_fields.clear() + self._cmsg.Clear(cmessages_to_release) + + def IsInitialized(self, errors=None): + if self._cmsg.IsInitialized(): + return True + if errors is not None: + errors.extend(self.FindInitializationErrors()); + return False + + def SerializeToString(self): + if not self.IsInitialized(): + raise message.EncodeError( + 'Message %s is missing required fields: %s' % ( + self._cmsg.full_name, ','.join(self.FindInitializationErrors()))) + return self._cmsg.SerializeToString() + + def SerializePartialToString(self): + return self._cmsg.SerializePartialToString() + + def ParseFromString(self, serialized): + self.Clear() + self.MergeFromString(serialized) + + def MergeFromString(self, serialized): + byte_size = self._cmsg.MergeFromString(serialized) + if byte_size < 0: + raise message.DecodeError('Unable to merge from string.') + return byte_size + + 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__)) + self._cmsg.MergeFrom(msg._cmsg) + + def CopyFrom(self, msg): + self._cmsg.CopyFrom(msg._cmsg) + + def ByteSize(self): + return self._cmsg.ByteSize() + + def SetInParent(self): + return self._cmsg.SetInParent() + + def ListFields(self): + all_fields = [] + field_list = self._cmsg.ListFields() + fields_by_name = cls.DESCRIPTOR.fields_by_name + for is_extension, field_name in field_list: + if is_extension: + extension = cls._extensions_by_name[field_name] + all_fields.append((extension, self.Extensions[extension])) + else: + field_descriptor = fields_by_name[field_name] + all_fields.append( + (field_descriptor, getattr(self, field_name))) + all_fields.sort(key=lambda item: item[0].number) + return all_fields + + def FindInitializationErrors(self): + return self._cmsg.FindInitializationErrors() + + def __str__(self): + return str(self._cmsg) + + def __eq__(self, other): + if self is other: + return True + if not isinstance(other, self.__class__): + return False + return self.ListFields() == other.ListFields() + + def __ne__(self, other): + return not self == other + + def __hash__(self): + raise TypeError('unhashable object') + + def __unicode__(self): + # Lazy import to prevent circular import when text_format imports this file. + from google.protobuf import text_format + return text_format.MessageToString(self, as_utf8=True).decode('utf-8') + + # Attach the local methods to the message class. + for key, value in locals().copy().iteritems(): + if key not in ('key', 'value', '__builtins__', '__name__', '__doc__'): + setattr(cls, key, value) + + # Static methods: + + def RegisterExtension(extension_handle): + extension_handle.containing_type = cls.DESCRIPTOR + cls._extensions_by_name[extension_handle.full_name] = extension_handle + + if _IsMessageSetExtension(extension_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(string): + msg = cls() + msg.MergeFromString(string) + return msg + cls.FromString = staticmethod(FromString) + + + +def _AddPropertiesForExtensions(message_descriptor, cls): + """Adds properties for all fields in this protocol message type.""" + extension_dict = message_descriptor.extensions_by_name + for extension_name, extension_field in extension_dict.iteritems(): + constant_name = extension_name.upper() + '_FIELD_NUMBER' + setattr(cls, constant_name, extension_field.number) |