# Protocol Buffers - Google's data interchange format # Copyright 2008 Google Inc. All rights reserved. # http://code.google.com/p/protobuf/ # # 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. """Descriptors essentially contain exactly the information found in a .proto file, in types that make this information accessible in Python. """ __author__ = 'robinson@google.com (Will Robinson)' from google.protobuf.internal import api_implementation if api_implementation.Type() == 'cpp': if api_implementation.Version() == 2: from google.protobuf.internal.cpp import _message else: from google.protobuf.internal import cpp_message class Error(Exception): """Base error for this module.""" class TypeTransformationError(Error): """Error transforming between python proto type and corresponding C++ type.""" class DescriptorBase(object): """Descriptors base class. This class is the base of all descriptor classes. It provides common options related functionaility. Attributes: has_options: True if the descriptor has non-default options. Usually it is not necessary to read this -- just call GetOptions() which will happily return the default instance. However, it's sometimes useful for efficiency, and also useful inside the protobuf implementation to avoid some bootstrapping issues. """ def __init__(self, options, options_class_name): """Initialize the descriptor given its options message and the name of the class of the options message. The name of the class is required in case the options message is None and has to be created. """ self._options = options self._options_class_name = options_class_name # Does this descriptor have non-default options? self.has_options = options is not None def _SetOptions(self, options, options_class_name): """Sets the descriptor's options This function is used in generated proto2 files to update descriptor options. It must not be used outside proto2. """ self._options = options self._options_class_name = options_class_name # Does this descriptor have non-default options? self.has_options = options is not None def GetOptions(self): """Retrieves descriptor options. This method returns the options set or creates the default options for the descriptor. """ if self._options: return self._options from google.protobuf import descriptor_pb2 try: options_class = getattr(descriptor_pb2, self._options_class_name) except AttributeError: raise RuntimeError('Unknown options class name %s!' % (self._options_class_name)) self._options = options_class() return self._options class _NestedDescriptorBase(DescriptorBase): """Common class for descriptors that can be nested.""" def __init__(self, options, options_class_name, name, full_name, file, containing_type, serialized_start=None, serialized_end=None): """Constructor. Args: options: Protocol message options or None to use default message options. options_class_name: (str) The class name of the above options. name: (str) Name of this protocol message type. full_name: (str) Fully-qualified name of this protocol message type, which will include protocol "package" name and the name of any enclosing types. file: (FileDescriptor) Reference to file info. containing_type: if provided, this is a nested descriptor, with this descriptor as parent, otherwise None. serialized_start: The start index (inclusive) in block in the file.serialized_pb that describes this descriptor. serialized_end: The end index (exclusive) in block in the file.serialized_pb that describes this descriptor. """ super(_NestedDescriptorBase, self).__init__( options, options_class_name) self.name = name # TODO(falk): Add function to calculate full_name instead of having it in # memory? self.full_name = full_name self.file = file self.containing_type = containing_type self._serialized_start = serialized_start self._serialized_end = serialized_end def GetTopLevelContainingType(self): """Returns the root if this is a nested type, or itself if its the root.""" desc = self while desc.containing_type is not None: desc = desc.containing_type return desc def CopyToProto(self, proto): """Copies this to the matching proto in descriptor_pb2. Args: proto: An empty proto instance from descriptor_pb2. Raises: Error: If self couldnt be serialized, due to to few constructor arguments. """ if (self.file is not None and self._serialized_start is not None and self._serialized_end is not None): proto.ParseFromString(self.file.serialized_pb[ self._serialized_start:self._serialized_end]) else: raise Error('Descriptor does not contain serialization.') class Descriptor(_NestedDescriptorBase): """Descriptor for a protocol message type. A Descriptor instance has the following attributes: name: (str) Name of this protocol message type. full_name: (str) Fully-qualified name of this protocol message type, which will include protocol "package" name and the name of any enclosing types. containing_type: (Descriptor) Reference to the descriptor of the type containing us, or None if this is top-level. fields: (list of FieldDescriptors) Field descriptors for all fields in this type. fields_by_number: (dict int -> FieldDescriptor) Same FieldDescriptor objects as in |fields|, but indexed by "number" attribute in each FieldDescriptor. fields_by_name: (dict str -> FieldDescriptor) Same FieldDescriptor objects as in |fields|, but indexed by "name" attribute in each FieldDescriptor. nested_types: (list of Descriptors) Descriptor references for all protocol message types nested within this one. nested_types_by_name: (dict str -> Descriptor) Same Descriptor objects as in |nested_types|, but indexed by "name" attribute in each Descriptor. enum_types: (list of EnumDescriptors) EnumDescriptor references for all enums contained within this type. enum_types_by_name: (dict str ->EnumDescriptor) Same EnumDescriptor objects as in |enum_types|, but indexed by "name" attribute in each EnumDescriptor. enum_values_by_name: (dict str -> EnumValueDescriptor) Dict mapping from enum value name to EnumValueDescriptor for that value. extensions: (list of FieldDescriptor) All extensions defined directly within this message type (NOT within a nested type). extensions_by_name: (dict, string -> FieldDescriptor) Same FieldDescriptor objects as |extensions|, but indexed by "name" attribute of each FieldDescriptor. is_extendable: Does this type define any extension ranges? options: (descriptor_pb2.MessageOptions) Protocol message options or None to use default message options. file: (FileDescriptor) Reference to file descriptor. """ def __init__(self, name, full_name, filename, containing_type, fields, nested_types, enum_types, extensions, options=None, is_extendable=True, extension_ranges=None, file=None, serialized_start=None, serialized_end=None): """Arguments to __init__() are as described in the description of Descriptor fields above. Note that filename is an obsolete argument, that is not used anymore. Please use file.name to access this as an attribute. """ super(Descriptor, self).__init__( options, 'MessageOptions', name, full_name, file, containing_type, serialized_start=serialized_start, serialized_end=serialized_start) # We have fields in addition to fields_by_name and fields_by_number, # so that: # 1. Clients can index fields by "order in which they're listed." # 2. Clients can easily iterate over all fields with the terse # syntax: for f in descriptor.fields: ... self.fields = fields for field in self.fields: field.containing_type = self self.fields_by_number = dict((f.number, f) for f in fields) self.fields_by_name = dict((f.name, f) for f in fields) self.nested_types = nested_types self.nested_types_by_name = dict((t.name, t) for t in nested_types) self.enum_types = enum_types for enum_type in self.enum_types: enum_type.containing_type = self self.enum_types_by_name = dict((t.name, t) for t in enum_types) self.enum_values_by_name = dict( (v.name, v) for t in enum_types for v in t.values) self.extensions = extensions for extension in self.extensions: extension.extension_scope = self self.extensions_by_name = dict((f.name, f) for f in extensions) self.is_extendable = is_extendable self.extension_ranges = extension_ranges self._serialized_start = serialized_start self._serialized_end = serialized_end def EnumValueName(self, enum, value): """Returns the string name of an enum value. This is just a small helper method to simplify a common operation. Args: enum: string name of the Enum. value: int, value of the enum. Returns: string name of the enum value. Raises: KeyError if either the Enum doesn't exist or the value is not a valid value for the enum. """ return self.enum_types_by_name[enum].values_by_number[value].name def CopyToProto(self, proto): """Copies this to a descriptor_pb2.DescriptorProto. Args: proto: An empty descriptor_pb2.DescriptorProto. """ # This function is overriden to give a better doc comment. super(Descriptor, self).CopyToProto(proto) # TODO(robinson): We should have aggressive checking here, # for example: # * If you specify a repeated field, you should not be allowed # to specify a default value. # * [Other examples here as needed]. # # TODO(robinson): for this and other *Descriptor classes, we # might also want to lock things down aggressively (e.g., # prevent clients from setting the attributes). Having # stronger invariants here in general will reduce the number # of runtime checks we must do in reflection.py... class FieldDescriptor(DescriptorBase): """Descriptor for a single field in a .proto file. A FieldDescriptor instance has the following attributes: name: (str) Name of this field, exactly as it appears in .proto. full_name: (str) Name of this field, including containing scope. This is particularly relevant for extensions. index: (int) Dense, 0-indexed index giving the order that this field textually appears within its message in the .proto file. number: (int) Tag number declared for this field in the .proto file. type: (One of the TYPE_* constants below) Declared type. cpp_type: (One of the CPPTYPE_* constants below) C++ type used to represent this field. label: (One of the LABEL_* constants below) Tells whether this field is optional, required, or repeated. has_default_value: (bool) True if this field has a default value defined, otherwise false. default_value: (Varies) Default value of this field. Only meaningful for non-repeated scalar fields. Repeated fields should always set this to [], and non-repeated composite fields should always set this to None. containing_type: (Descriptor) Descriptor of the protocol message type that contains this field. Set by the Descriptor constructor if we're passed into one. Somewhat confusingly, for extension fields, this is the descriptor of the EXTENDED message, not the descriptor of the message containing this field. (See is_extension and extension_scope below). message_type: (Descriptor) If a composite field, a descriptor of the message type contained in this field. Otherwise, this is None. enum_type: (EnumDescriptor) If this field contains an enum, a descriptor of that enum. Otherwise, this is None. is_extension: True iff this describes an extension field. extension_scope: (Descriptor) Only meaningful if is_extension is True. Gives the message that immediately contains this extension field. Will be None iff we're a top-level (file-level) extension field. options: (descriptor_pb2.FieldOptions) Protocol message field options or None to use default field options. """ # Must be consistent with C++ FieldDescriptor::Type enum in # descriptor.h. # # TODO(robinson): Find a way to eliminate this repetition. TYPE_DOUBLE = 1 TYPE_FLOAT = 2 TYPE_INT64 = 3 TYPE_UINT64 = 4 TYPE_INT32 = 5 TYPE_FIXED64 = 6 TYPE_FIXED32 = 7 TYPE_BOOL = 8 TYPE_STRING = 9 TYPE_GROUP = 10 TYPE_MESSAGE = 11 TYPE_BYTES = 12 TYPE_UINT32 = 13 TYPE_ENUM = 14 TYPE_SFIXED32 = 15 TYPE_SFIXED64 = 16 TYPE_SINT32 = 17 TYPE_SINT64 = 18 MAX_TYPE = 18 # Must be consistent with C++ FieldDescriptor::CppType enum in # descriptor.h. # # TODO(robinson): Find a way to eliminate this repetition. CPPTYPE_INT32 = 1 CPPTYPE_INT64 = 2 CPPTYPE_UINT32 = 3 CPPTYPE_UINT64 = 4 CPPTYPE_DOUBLE = 5 CPPTYPE_FLOAT = 6 CPPTYPE_BOOL = 7 CPPTYPE_ENUM = 8 CPPTYPE_STRING = 9 CPPTYPE_MESSAGE = 10 MAX_CPPTYPE = 10 _PYTHON_TO_CPP_PROTO_TYPE_MAP = { TYPE_DOUBLE: CPPTYPE_DOUBLE, TYPE_FLOAT: CPPTYPE_FLOAT, TYPE_ENUM: CPPTYPE_ENUM, TYPE_INT64: CPPTYPE_INT64, TYPE_SINT64: CPPTYPE_INT64, TYPE_SFIXED64: CPPTYPE_INT64, TYPE_UINT64: CPPTYPE_UINT64, TYPE_FIXED64: CPPTYPE_UINT64, TYPE_INT32: CPPTYPE_INT32, TYPE_SFIXED32: CPPTYPE_INT32, TYPE_SINT32: CPPTYPE_INT32, TYPE_UINT32: CPPTYPE_UINT32, TYPE_FIXED32: CPPTYPE_UINT32, TYPE_BYTES: CPPTYPE_STRING, TYPE_STRING: CPPTYPE_STRING, TYPE_BOOL: CPPTYPE_BOOL, TYPE_MESSAGE: CPPTYPE_MESSAGE, TYPE_GROUP: CPPTYPE_MESSAGE } # Must be consistent with C++ FieldDescriptor::Label enum in # descriptor.h. # # TODO(robinson): Find a way to eliminate this repetition. LABEL_OPTIONAL = 1 LABEL_REQUIRED = 2 LABEL_REPEATED = 3 MAX_LABEL = 3 def __init__(self, name, full_name, index, number, type, cpp_type, label, default_value, message_type, enum_type, containing_type, is_extension, extension_scope, options=None, has_default_value=True): """The arguments are as described in the description of FieldDescriptor attributes above. Note that containing_type may be None, and may be set later if necessary (to deal with circular references between message types, for example). Likewise for extension_scope. """ super(FieldDescriptor, self).__init__(options, 'FieldOptions') self.name = name self.full_name = full_name self.index = index self.number = number self.type = type self.cpp_type = cpp_type self.label = label self.has_default_value = has_default_value self.default_value = default_value self.containing_type = containing_type self.message_type = message_type self.enum_type = enum_type self.is_extension = is_extension self.extension_scope = extension_scope if api_implementation.Type() == 'cpp': if is_extension: if api_implementation.Version() == 2: self._cdescriptor = _message.GetExtensionDescriptor(full_name) else: self._cdescriptor = cpp_message.GetExtensionDescriptor(full_name) else: if api_implementation.Version() == 2: self._cdescriptor = _message.GetFieldDescriptor(full_name) else: self._cdescriptor = cpp_message.GetFieldDescriptor(full_name) else: self._cdescriptor = None @staticmethod def ProtoTypeToCppProtoType(proto_type): """Converts from a Python proto type to a C++ Proto Type. The Python ProtocolBuffer classes specify both the 'Python' datatype and the 'C++' datatype - and they're not the same. This helper method should translate from one to another. Args: proto_type: the Python proto type (descriptor.FieldDescriptor.TYPE_*) Returns: descriptor.FieldDescriptor.CPPTYPE_*, the C++ type. Raises: TypeTransformationError: when the Python proto type isn't known. """ try: return FieldDescriptor._PYTHON_TO_CPP_PROTO_TYPE_MAP[proto_type] except KeyError: raise TypeTransformationError('Unknown proto_type: %s' % proto_type) class EnumDescriptor(_NestedDescriptorBase): """Descriptor for an enum defined in a .proto file. An EnumDescriptor instance has the following attributes: name: (str) Name of the enum type. full_name: (str) Full name of the type, including package name and any enclosing type(s). values: (list of EnumValueDescriptors) List of the values in this enum. values_by_name: (dict str -> EnumValueDescriptor) Same as |values|, but indexed by the "name" field of each EnumValueDescriptor. values_by_number: (dict int -> EnumValueDescriptor) Same as |values|, but indexed by the "number" field of each EnumValueDescriptor. containing_type: (Descriptor) Descriptor of the immediate containing type of this enum, or None if this is an enum defined at the top level in a .proto file. Set by Descriptor's constructor if we're passed into one. file: (FileDescriptor) Reference to file descriptor. options: (descriptor_pb2.EnumOptions) Enum options message or None to use default enum options. """ def __init__(self, name, full_name, filename, values, containing_type=None, options=None, file=None, serialized_start=None, serialized_end=None): """Arguments are as described in the attribute description above. Note that filename is an obsolete argument, that is not used anymore. Please use file.name to access this as an attribute. """ super(EnumDescriptor, self).__init__( options, 'EnumOptions', name, full_name, file, containing_type, serialized_start=serialized_start, serialized_end=serialized_start) self.values = values for value in self.values: value.type = self self.values_by_name = dict((v.name, v) for v in values) self.values_by_number = dict((v.number, v) for v in values) self._serialized_start = serialized_start self._serialized_end = serialized_end def CopyToProto(self, proto): """Copies this to a descriptor_pb2.EnumDescriptorProto. Args: proto: An empty descriptor_pb2.EnumDescriptorProto. """ # This function is overriden to give a better doc comment. super(EnumDescriptor, self).CopyToProto(proto) class EnumValueDescriptor(DescriptorBase): """Descriptor for a single value within an enum. name: (str) Name of this value. index: (int) Dense, 0-indexed index giving the order that this value appears textually within its enum in the .proto file. number: (int) Actual number assigned to this enum value. type: (EnumDescriptor) EnumDescriptor to which this value belongs. Set by EnumDescriptor's constructor if we're passed into one. options: (descriptor_pb2.EnumValueOptions) Enum value options message or None to use default enum value options options. """ def __init__(self, name, index, number, type=None, options=None): """Arguments are as described in the attribute description above.""" super(EnumValueDescriptor, self).__init__(options, 'EnumValueOptions') self.name = name self.index = index self.number = number self.type = type class ServiceDescriptor(_NestedDescriptorBase): """Descriptor for a service. name: (str) Name of the service. full_name: (str) Full name of the service, including package name. index: (int) 0-indexed index giving the order that this services definition appears withing the .proto file. methods: (list of MethodDescriptor) List of methods provided by this service. options: (descriptor_pb2.ServiceOptions) Service options message or None to use default service options. file: (FileDescriptor) Reference to file info. """ def __init__(self, name, full_name, index, methods, options=None, file=None, serialized_start=None, serialized_end=None): super(ServiceDescriptor, self).__init__( options, 'ServiceOptions', name, full_name, file, None, serialized_start=serialized_start, serialized_end=serialized_end) self.index = index self.methods = methods # Set the containing service for each method in this service. for method in self.methods: method.containing_service = self def FindMethodByName(self, name): """Searches for the specified method, and returns its descriptor.""" for method in self.methods: if name == method.name: return method return None def CopyToProto(self, proto): """Copies this to a descriptor_pb2.ServiceDescriptorProto. Args: proto: An empty descriptor_pb2.ServiceDescriptorProto. """ # This function is overriden to give a better doc comment. super(ServiceDescriptor, self).CopyToProto(proto) class MethodDescriptor(DescriptorBase): """Descriptor for a method in a service. name: (str) Name of the method within the service. full_name: (str) Full name of method. index: (int) 0-indexed index of the method inside the service. containing_service: (ServiceDescriptor) The service that contains this method. input_type: The descriptor of the message that this method accepts. output_type: The descriptor of the message that this method returns. options: (descriptor_pb2.MethodOptions) Method options message or None to use default method options. """ def __init__(self, name, full_name, index, containing_service, input_type, output_type, options=None): """The arguments are as described in the description of MethodDescriptor attributes above. Note that containing_service may be None, and may be set later if necessary. """ super(MethodDescriptor, self).__init__(options, 'MethodOptions') self.name = name self.full_name = full_name self.index = index self.containing_service = containing_service self.input_type = input_type self.output_type = output_type class FileDescriptor(DescriptorBase): """Descriptor for a file. Mimics the descriptor_pb2.FileDescriptorProto. name: name of file, relative to root of source tree. package: name of the package serialized_pb: (str) Byte string of serialized descriptor_pb2.FileDescriptorProto. """ def __init__(self, name, package, options=None, serialized_pb=None): """Constructor.""" super(FileDescriptor, self).__init__(options, 'FileOptions') self.message_types_by_name = {} self.name = name self.package = package self.serialized_pb = serialized_pb if (api_implementation.Type() == 'cpp' and self.serialized_pb is not None): if api_implementation.Version() == 2: _message.BuildFile(self.serialized_pb) else: cpp_message.BuildFile(self.serialized_pb) def CopyToProto(self, proto): """Copies this to a descriptor_pb2.FileDescriptorProto. Args: proto: An empty descriptor_pb2.FileDescriptorProto. """ proto.ParseFromString(self.serialized_pb) def _ParseOptions(message, string): """Parses serialized options. This helper function is used to parse serialized options in generated proto2 files. It must not be used outside proto2. """ message.ParseFromString(string) return message def MakeDescriptor(desc_proto, package=''): """Make a protobuf Descriptor given a DescriptorProto protobuf. Args: desc_proto: The descriptor_pb2.DescriptorProto protobuf message. package: Optional package name for the new message Descriptor (string). Returns: A Descriptor for protobuf messages. """ full_message_name = [desc_proto.name] if package: full_message_name.insert(0, package) fields = [] for field_proto in desc_proto.field: full_name = '.'.join(full_message_name + [field_proto.name]) field = FieldDescriptor( field_proto.name, full_name, field_proto.number - 1, field_proto.number, field_proto.type, FieldDescriptor.ProtoTypeToCppProtoType(field_proto.type), field_proto.label, None, None, None, None, False, None, has_default_value=False) fields.append(field) desc_name = '.'.join(full_message_name) return Descriptor(desc_proto.name, desc_name, None, None, fields, [], [], [])