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# Copyright 2019 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.
import enum
from google.protobuf import descriptor_pb2
from proto import _file_info
from proto import _package_info
from proto.marshal.rules.enums import EnumRule
class ProtoEnumMeta(enum.EnumMeta):
"""A metaclass for building and registering protobuf enums."""
def __new__(mcls, name, bases, attrs):
# Do not do any special behavior for `proto.Enum` itself.
if bases[0] == enum.IntEnum:
return super().__new__(mcls, name, bases, attrs)
# Get the essential information about the proto package, and where
# this component belongs within the file.
package, marshal = _package_info.compile(name, attrs)
# Determine the local path of this proto component within the file.
local_path = tuple(attrs.get("__qualname__", name).split("."))
# Sanity check: We get the wrong full name if a class is declared
# inside a function local scope; correct this.
if "<locals>" in local_path:
ix = local_path.index("<locals>")
local_path = local_path[: ix - 1] + local_path[ix + 1 :]
# Determine the full name in protocol buffers.
full_name = ".".join((package,) + local_path).lstrip(".")
filename = _file_info._FileInfo.proto_file_name(
attrs.get("__module__", name.lower())
)
# Retrieve any enum options.
# We expect something that looks like an EnumOptions message,
# either an actual instance or a dict-like representation.
pb_options = "_pb_options"
opts = attrs.pop(pb_options, {})
# This is the only portable way to remove the _pb_options name
# from the enum attrs.
# In 3.7 onwards, we can define an _ignore_ attribute and do some
# mucking around with that.
if pb_options in attrs._member_names:
if isinstance(attrs._member_names, list):
idx = attrs._member_names.index(pb_options)
attrs._member_names.pop(idx)
else: # Python 3.11.0b3
del attrs._member_names[pb_options]
# Make the descriptor.
enum_desc = descriptor_pb2.EnumDescriptorProto(
name=name,
# Note: the superclass ctor removes the variants, so get them now.
# Note: proto3 requires that the first variant value be zero.
value=sorted(
(
descriptor_pb2.EnumValueDescriptorProto(name=name, number=number)
# Minor hack to get all the enum variants out.
# Use the `_member_names` property to get only the enum members
# See https://github.com/googleapis/proto-plus-python/issues/490
for name, number in attrs.items()
if name in attrs._member_names and isinstance(number, int)
),
key=lambda v: v.number,
),
options=opts,
)
file_info = _file_info._FileInfo.maybe_add_descriptor(filename, package)
if len(local_path) == 1:
file_info.descriptor.enum_type.add().MergeFrom(enum_desc)
else:
file_info.nested_enum[local_path] = enum_desc
# Run the superclass constructor.
cls = super().__new__(mcls, name, bases, attrs)
# We can't just add a "_meta" element to attrs because the Enum
# machinery doesn't know what to do with a non-int value.
# The pb is set later, in generate_file_pb
cls._meta = _EnumInfo(full_name=full_name, pb=None)
file_info.enums[full_name] = cls
# Register the enum with the marshal.
marshal.register(cls, EnumRule(cls))
# Generate the descriptor for the file if it is ready.
if file_info.ready(new_class=cls):
file_info.generate_file_pb(new_class=cls, fallback_salt=full_name)
# Done; return the class.
return cls
class Enum(enum.IntEnum, metaclass=ProtoEnumMeta):
"""A enum object that also builds a protobuf enum descriptor."""
def _comparable(self, other):
# Avoid 'isinstance' to prevent other IntEnums from matching
return type(other) in (type(self), int)
def __hash__(self):
return hash(self.value)
def __eq__(self, other):
if not self._comparable(other):
return NotImplemented
return self.value == int(other)
def __ne__(self, other):
if not self._comparable(other):
return NotImplemented
return self.value != int(other)
def __lt__(self, other):
if not self._comparable(other):
return NotImplemented
return self.value < int(other)
def __le__(self, other):
if not self._comparable(other):
return NotImplemented
return self.value <= int(other)
def __ge__(self, other):
if not self._comparable(other):
return NotImplemented
return self.value >= int(other)
def __gt__(self, other):
if not self._comparable(other):
return NotImplemented
return self.value > int(other)
class _EnumInfo:
def __init__(self, *, full_name: str, pb):
self.full_name = full_name
self.pb = pb
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