166 lines
5.2 KiB
Python
166 lines
5.2 KiB
Python
# Copyright 2018 Google LLC
|
|
#
|
|
# 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
|
|
#
|
|
# https://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.
|
|
|
|
from enum import EnumMeta
|
|
|
|
from google.protobuf import descriptor_pb2
|
|
from google.protobuf.internal.enum_type_wrapper import EnumTypeWrapper
|
|
|
|
from proto.primitives import ProtoType
|
|
|
|
|
|
class Field:
|
|
"""A representation of a type of field in protocol buffers."""
|
|
|
|
# Fields are NOT repeated nor maps.
|
|
# The RepeatedField overrides this values.
|
|
repeated = False
|
|
|
|
def __init__(
|
|
self,
|
|
proto_type,
|
|
*,
|
|
number: int,
|
|
message=None,
|
|
enum=None,
|
|
oneof: str = None,
|
|
json_name: str = None,
|
|
optional: bool = False
|
|
):
|
|
# This class is not intended to stand entirely alone;
|
|
# data is augmented by the metaclass for Message.
|
|
self.mcls_data = None
|
|
self.parent = None
|
|
|
|
# If the proto type sent is an object or a string, it is really
|
|
# a message or enum.
|
|
if not isinstance(proto_type, int):
|
|
# Note: We only support the "shortcut syntax" for enums
|
|
# when receiving the actual class.
|
|
if isinstance(proto_type, (EnumMeta, EnumTypeWrapper)):
|
|
enum = proto_type
|
|
proto_type = ProtoType.ENUM
|
|
else:
|
|
message = proto_type
|
|
proto_type = ProtoType.MESSAGE
|
|
|
|
# Save the direct arguments.
|
|
self.number = number
|
|
self.proto_type = proto_type
|
|
self.message = message
|
|
self.enum = enum
|
|
self.json_name = json_name
|
|
self.optional = optional
|
|
self.oneof = oneof
|
|
|
|
# Once the descriptor is accessed the first time, cache it.
|
|
# This is important because in rare cases the message or enum
|
|
# types are written later.
|
|
self._descriptor = None
|
|
|
|
@property
|
|
def descriptor(self):
|
|
"""Return the descriptor for the field."""
|
|
if not self._descriptor:
|
|
# Resolve the message type, if any, to a string.
|
|
type_name = None
|
|
if isinstance(self.message, str):
|
|
if not self.message.startswith(self.package):
|
|
self.message = "{package}.{name}".format(
|
|
package=self.package,
|
|
name=self.message,
|
|
)
|
|
type_name = self.message
|
|
elif self.message:
|
|
type_name = (
|
|
self.message.DESCRIPTOR.full_name
|
|
if hasattr(self.message, "DESCRIPTOR")
|
|
else self.message._meta.full_name
|
|
)
|
|
elif isinstance(self.enum, str):
|
|
if not self.enum.startswith(self.package):
|
|
self.enum = "{package}.{name}".format(
|
|
package=self.package,
|
|
name=self.enum,
|
|
)
|
|
type_name = self.enum
|
|
elif self.enum:
|
|
type_name = (
|
|
self.enum.DESCRIPTOR.full_name
|
|
if hasattr(self.enum, "DESCRIPTOR")
|
|
else self.enum._meta.full_name
|
|
)
|
|
|
|
# Set the descriptor.
|
|
self._descriptor = descriptor_pb2.FieldDescriptorProto(
|
|
name=self.name,
|
|
number=self.number,
|
|
label=3 if self.repeated else 1,
|
|
type=self.proto_type,
|
|
type_name=type_name,
|
|
json_name=self.json_name,
|
|
proto3_optional=self.optional,
|
|
)
|
|
|
|
# Return the descriptor.
|
|
return self._descriptor
|
|
|
|
@property
|
|
def name(self) -> str:
|
|
"""Return the name of the field."""
|
|
return self.mcls_data["name"]
|
|
|
|
@property
|
|
def package(self) -> str:
|
|
"""Return the package of the field."""
|
|
return self.mcls_data["package"]
|
|
|
|
@property
|
|
def pb_type(self):
|
|
"""Return the composite type of the field, or the primitive type if a primitive."""
|
|
# For enums, return the Python enum.
|
|
if self.enum:
|
|
return self.enum
|
|
|
|
# For primitive fields, we still want to know
|
|
# what the type is.
|
|
if not self.message:
|
|
return self.proto_type
|
|
|
|
# Return the internal protobuf message.
|
|
if hasattr(self.message, "_meta"):
|
|
return self.message.pb()
|
|
return self.message
|
|
|
|
|
|
class RepeatedField(Field):
|
|
"""A representation of a repeated field in protocol buffers."""
|
|
|
|
repeated = True
|
|
|
|
|
|
class MapField(Field):
|
|
"""A representation of a map field in protocol buffers."""
|
|
|
|
def __init__(self, key_type, value_type, *, number: int, message=None, enum=None):
|
|
super().__init__(value_type, number=number, message=message, enum=enum)
|
|
self.map_key_type = key_type
|
|
|
|
|
|
__all__ = (
|
|
"Field",
|
|
"MapField",
|
|
"RepeatedField",
|
|
)
|