blob: d9a0cfff93d7dd79041b250efcd751e8324b88e1 [file] [log] [blame]
#!/usr/bin/env python
#
# Copyright 2007 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""Descriptors essentially contain exactly the information found in a .proto
file, in types that make this information accessible in Python.
"""
from google.net.proto2.python.internal import api_implementation
if api_implementation.Type() == 'cpp':
import os
import uuid
if api_implementation.Version() == 2:
from google.net.proto2.python.internal.cpp import _message
else:
from google.net.proto2.python.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
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
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.net.proto2.proto 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
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)
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
for nested_type in nested_types:
nested_type.containing_type = self
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.
"""
super(Descriptor, self).CopyToProto(proto)
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.
"""
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
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
}
LABEL_OPTIONAL = 1
LABEL_REQUIRED = 2
LABEL_REPEATED = 3
MAX_LABEL = 3
MAX_FIELD_NUMBER = (1 << 29) - 1
FIRST_RESERVED_FIELD_NUMBER = 19000
LAST_RESERVED_FIELD_NUMBER = 19999
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.Message._GetExtensionDescriptor(full_name))
else:
self._cdescriptor = cpp_message.GetExtensionDescriptor(full_name)
else:
if api_implementation.Version() == 2:
self._cdescriptor = _message.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.
"""
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
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.
"""
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.
Note that enum_types_by_name, extensions_by_name, and dependencies
fields are only set by the message_factory module, and not by the
generated proto code.
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.
dependencies: List of other files this file depends on.
message_types_by_name: Dict of message names of their descriptors.
enum_types_by_name: Dict of enum names and their descriptors.
extensions_by_name: Dict of extension names and their descriptors.
"""
def __init__(self, name, package, options=None, serialized_pb=None,
dependencies=None):
"""Constructor."""
super(FileDescriptor, self).__init__(options, 'FileOptions')
self.message_types_by_name = {}
self.name = name
self.package = package
self.serialized_pb = serialized_pb
self.enum_types_by_name = {}
self.extensions_by_name = {}
self.dependencies = (dependencies or [])
if (api_implementation.Type() == 'cpp' and
self.serialized_pb is not None):
if api_implementation.Version() == 2:
_message.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='', build_file_if_cpp=True):
"""Make a protobuf Descriptor given a DescriptorProto protobuf.
Handles nested descriptors. Note that this is limited to the scope of defining
a message inside of another message. Composite fields can currently only be
resolved if the message is defined in the same scope as the field.
Args:
desc_proto: The descriptor_pb2.DescriptorProto protobuf message.
package: Optional package name for the new message Descriptor (string).
build_file_if_cpp: Update the C++ descriptor pool if api matches.
Set to False on recursion, so no duplicates are created.
Returns:
A Descriptor for protobuf messages.
"""
if api_implementation.Type() == 'cpp' and build_file_if_cpp:
from google.net.proto2.proto import descriptor_pb2
file_descriptor_proto = descriptor_pb2.FileDescriptorProto()
file_descriptor_proto.message_type.add().MergeFrom(desc_proto)
proto_name = str(uuid.uuid4())
if package:
file_descriptor_proto.name = os.path.join(package.replace('.', '/'),
proto_name + '.proto')
file_descriptor_proto.package = package
else:
file_descriptor_proto.name = proto_name + '.proto'
if api_implementation.Version() == 2:
_message.Message._BuildFile(file_descriptor_proto.SerializeToString())
else:
cpp_message.BuildFile(file_descriptor_proto.SerializeToString())
full_message_name = [desc_proto.name]
if package: full_message_name.insert(0, package)
enum_types = {}
for enum_proto in desc_proto.enum_type:
full_name = '.'.join(full_message_name + [enum_proto.name])
enum_desc = EnumDescriptor(
enum_proto.name, full_name, None, [
EnumValueDescriptor(enum_val.name, ii, enum_val.number)
for ii, enum_val in enumerate(enum_proto.value)])
enum_types[full_name] = enum_desc
nested_types = {}
for nested_proto in desc_proto.nested_type:
full_name = '.'.join(full_message_name + [nested_proto.name])
nested_desc = MakeDescriptor(nested_proto,
package='.'.join(full_message_name),
build_file_if_cpp=False)
nested_types[full_name] = nested_desc
fields = []
for field_proto in desc_proto.field:
full_name = '.'.join(full_message_name + [field_proto.name])
enum_desc = None
nested_desc = None
if field_proto.HasField('type_name'):
type_name = field_proto.type_name
full_type_name = '.'.join(full_message_name +
[type_name[type_name.rfind('.')+1:]])
if full_type_name in nested_types:
nested_desc = nested_types[full_type_name]
elif full_type_name in enum_types:
enum_desc = enum_types[full_type_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, nested_desc, enum_desc, 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,
nested_types.values(), enum_types.values(), [])