Nat Noordanus be2a24d15c blacken
2020-05-27 11:25:00 +02:00

1149 lines
39 KiB
Python

import dataclasses
import enum
import inspect
import json
import struct
import sys
from abc import ABC
from base64 import b64encode, b64decode
from datetime import datetime, timedelta, timezone
from typing import (
Any,
AsyncGenerator,
Callable,
Collection,
Dict,
Generator,
Iterable,
List,
Mapping,
Optional,
SupportsBytes,
Tuple,
Type,
TypeVar,
Union,
get_type_hints,
TYPE_CHECKING,
)
import grpclib.const
import stringcase
from .casing import safe_snake_case
if TYPE_CHECKING:
from grpclib._protocols import IProtoMessage
from grpclib.client import Channel
from grpclib.metadata import Deadline
if not (sys.version_info.major == 3 and sys.version_info.minor >= 7):
# Apply backport of datetime.fromisoformat from 3.7
from backports.datetime_fromisoformat import MonkeyPatch
MonkeyPatch.patch_fromisoformat()
# Proto 3 data types
TYPE_ENUM = "enum"
TYPE_BOOL = "bool"
TYPE_INT32 = "int32"
TYPE_INT64 = "int64"
TYPE_UINT32 = "uint32"
TYPE_UINT64 = "uint64"
TYPE_SINT32 = "sint32"
TYPE_SINT64 = "sint64"
TYPE_FLOAT = "float"
TYPE_DOUBLE = "double"
TYPE_FIXED32 = "fixed32"
TYPE_SFIXED32 = "sfixed32"
TYPE_FIXED64 = "fixed64"
TYPE_SFIXED64 = "sfixed64"
TYPE_STRING = "string"
TYPE_BYTES = "bytes"
TYPE_MESSAGE = "message"
TYPE_MAP = "map"
# Fields that use a fixed amount of space (4 or 8 bytes)
FIXED_TYPES = [
TYPE_FLOAT,
TYPE_DOUBLE,
TYPE_FIXED32,
TYPE_SFIXED32,
TYPE_FIXED64,
TYPE_SFIXED64,
]
# Fields that are numerical 64-bit types
INT_64_TYPES = [TYPE_INT64, TYPE_UINT64, TYPE_SINT64, TYPE_FIXED64, TYPE_SFIXED64]
# Fields that are efficiently packed when
PACKED_TYPES = [
TYPE_ENUM,
TYPE_BOOL,
TYPE_INT32,
TYPE_INT64,
TYPE_UINT32,
TYPE_UINT64,
TYPE_SINT32,
TYPE_SINT64,
TYPE_FLOAT,
TYPE_DOUBLE,
TYPE_FIXED32,
TYPE_SFIXED32,
TYPE_FIXED64,
TYPE_SFIXED64,
]
# Wire types
# https://developers.google.com/protocol-buffers/docs/encoding#structure
WIRE_VARINT = 0
WIRE_FIXED_64 = 1
WIRE_LEN_DELIM = 2
WIRE_FIXED_32 = 5
# Mappings of which Proto 3 types correspond to which wire types.
WIRE_VARINT_TYPES = [
TYPE_ENUM,
TYPE_BOOL,
TYPE_INT32,
TYPE_INT64,
TYPE_UINT32,
TYPE_UINT64,
TYPE_SINT32,
TYPE_SINT64,
]
WIRE_FIXED_32_TYPES = [TYPE_FLOAT, TYPE_FIXED32, TYPE_SFIXED32]
WIRE_FIXED_64_TYPES = [TYPE_DOUBLE, TYPE_FIXED64, TYPE_SFIXED64]
WIRE_LEN_DELIM_TYPES = [TYPE_STRING, TYPE_BYTES, TYPE_MESSAGE, TYPE_MAP]
# Protobuf datetimes start at the Unix Epoch in 1970 in UTC.
def datetime_default_gen():
return datetime(1970, 1, 1, tzinfo=timezone.utc)
DATETIME_ZERO = datetime_default_gen()
class Casing(enum.Enum):
"""Casing constants for serialization."""
CAMEL = stringcase.camelcase
SNAKE = stringcase.snakecase
class _PLACEHOLDER:
pass
PLACEHOLDER: Any = _PLACEHOLDER()
@dataclasses.dataclass(frozen=True)
class FieldMetadata:
"""Stores internal metadata used for parsing & serialization."""
# Protobuf field number
number: int
# Protobuf type name
proto_type: str
# Map information if the proto_type is a map
map_types: Optional[Tuple[str, str]] = None
# Groups several "one-of" fields together
group: Optional[str] = None
# Describes the wrapped type (e.g. when using google.protobuf.BoolValue)
wraps: Optional[str] = None
@staticmethod
def get(field: dataclasses.Field) -> "FieldMetadata":
"""Returns the field metadata for a dataclass field."""
return field.metadata["betterproto"]
def dataclass_field(
number: int,
proto_type: str,
*,
map_types: Optional[Tuple[str, str]] = None,
group: Optional[str] = None,
wraps: Optional[str] = None,
) -> dataclasses.Field:
"""Creates a dataclass field with attached protobuf metadata."""
return dataclasses.field(
default=PLACEHOLDER,
metadata={
"betterproto": FieldMetadata(number, proto_type, map_types, group, wraps)
},
)
# Note: the fields below return `Any` to prevent type errors in the generated
# data classes since the types won't match with `Field` and they get swapped
# out at runtime. The generated dataclass variables are still typed correctly.
def enum_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_ENUM, group=group)
def bool_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_BOOL, group=group)
def int32_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_INT32, group=group)
def int64_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_INT64, group=group)
def uint32_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_UINT32, group=group)
def uint64_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_UINT64, group=group)
def sint32_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_SINT32, group=group)
def sint64_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_SINT64, group=group)
def float_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_FLOAT, group=group)
def double_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_DOUBLE, group=group)
def fixed32_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_FIXED32, group=group)
def fixed64_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_FIXED64, group=group)
def sfixed32_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_SFIXED32, group=group)
def sfixed64_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_SFIXED64, group=group)
def string_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_STRING, group=group)
def bytes_field(number: int, group: Optional[str] = None) -> Any:
return dataclass_field(number, TYPE_BYTES, group=group)
def message_field(
number: int, group: Optional[str] = None, wraps: Optional[str] = None
) -> Any:
return dataclass_field(number, TYPE_MESSAGE, group=group, wraps=wraps)
def map_field(
number: int, key_type: str, value_type: str, group: Optional[str] = None
) -> Any:
return dataclass_field(
number, TYPE_MAP, map_types=(key_type, value_type), group=group
)
class Enum(int, enum.Enum):
"""Protocol buffers enumeration base class. Acts like `enum.IntEnum`."""
@classmethod
def from_string(cls, name: str) -> int:
"""Return the value which corresponds to the string name."""
try:
return cls.__members__[name]
except KeyError as e:
raise ValueError(f"Unknown value {name} for enum {cls.__name__}") from e
def _pack_fmt(proto_type: str) -> str:
"""Returns a little-endian format string for reading/writing binary."""
return {
TYPE_DOUBLE: "<d",
TYPE_FLOAT: "<f",
TYPE_FIXED32: "<I",
TYPE_FIXED64: "<Q",
TYPE_SFIXED32: "<i",
TYPE_SFIXED64: "<q",
}[proto_type]
def encode_varint(value: int) -> bytes:
"""Encodes a single varint value for serialization."""
b: List[int] = []
if value < 0:
value += 1 << 64
bits = value & 0x7F
value >>= 7
while value:
b.append(0x80 | bits)
bits = value & 0x7F
value >>= 7
return bytes(b + [bits])
def _preprocess_single(proto_type: str, wraps: str, value: Any) -> bytes:
"""Adjusts values before serialization."""
if proto_type in [
TYPE_ENUM,
TYPE_BOOL,
TYPE_INT32,
TYPE_INT64,
TYPE_UINT32,
TYPE_UINT64,
]:
return encode_varint(value)
elif proto_type in [TYPE_SINT32, TYPE_SINT64]:
# Handle zig-zag encoding.
if value >= 0:
value = value << 1
else:
value = (value << 1) ^ (~0)
return encode_varint(value)
elif proto_type in FIXED_TYPES:
return struct.pack(_pack_fmt(proto_type), value)
elif proto_type == TYPE_STRING:
return value.encode("utf-8")
elif proto_type == TYPE_MESSAGE:
if isinstance(value, datetime):
# Convert the `datetime` to a timestamp message.
seconds = int(value.timestamp())
nanos = int(value.microsecond * 1e3)
value = _Timestamp(seconds=seconds, nanos=nanos)
elif isinstance(value, timedelta):
# Convert the `timedelta` to a duration message.
total_ms = value // timedelta(microseconds=1)
seconds = int(total_ms / 1e6)
nanos = int((total_ms % 1e6) * 1e3)
value = _Duration(seconds=seconds, nanos=nanos)
elif wraps:
if value is None:
return b""
value = _get_wrapper(wraps)(value=value)
return bytes(value)
return value
def _serialize_single(
field_number: int,
proto_type: str,
value: Any,
*,
serialize_empty: bool = False,
wraps: str = "",
) -> bytes:
"""Serializes a single field and value."""
value = _preprocess_single(proto_type, wraps, value)
output = b""
if proto_type in WIRE_VARINT_TYPES:
key = encode_varint(field_number << 3)
output += key + value
elif proto_type in WIRE_FIXED_32_TYPES:
key = encode_varint((field_number << 3) | 5)
output += key + value
elif proto_type in WIRE_FIXED_64_TYPES:
key = encode_varint((field_number << 3) | 1)
output += key + value
elif proto_type in WIRE_LEN_DELIM_TYPES:
if len(value) or serialize_empty or wraps:
key = encode_varint((field_number << 3) | 2)
output += key + encode_varint(len(value)) + value
else:
raise NotImplementedError(proto_type)
return output
def decode_varint(buffer: bytes, pos: int, signed: bool = False) -> Tuple[int, int]:
"""
Decode a single varint value from a byte buffer. Returns the value and the
new position in the buffer.
"""
result = 0
shift = 0
while 1:
b = buffer[pos]
result |= (b & 0x7F) << shift
pos += 1
if not (b & 0x80):
return (result, pos)
shift += 7
if shift >= 64:
raise ValueError("Too many bytes when decoding varint.")
@dataclasses.dataclass(frozen=True)
class ParsedField:
number: int
wire_type: int
value: Any
raw: bytes
def parse_fields(value: bytes) -> Generator[ParsedField, None, None]:
i = 0
while i < len(value):
start = i
num_wire, i = decode_varint(value, i)
number = num_wire >> 3
wire_type = num_wire & 0x7
decoded: Any = None
if wire_type == 0:
decoded, i = decode_varint(value, i)
elif wire_type == 1:
decoded, i = value[i : i + 8], i + 8
elif wire_type == 2:
length, i = decode_varint(value, i)
decoded = value[i : i + length]
i += length
elif wire_type == 5:
decoded, i = value[i : i + 4], i + 4
yield ParsedField(
number=number, wire_type=wire_type, value=decoded, raw=value[start:i]
)
# Bound type variable to allow methods to return `self` of subclasses
T = TypeVar("T", bound="Message")
class ProtoClassMetadata:
cls: Type["Message"]
def __init__(self, cls: Type["Message"]):
self.cls = cls
by_field = {}
by_group = {}
for field in dataclasses.fields(cls):
meta = FieldMetadata.get(field)
if meta.group:
# This is part of a one-of group.
by_field[field.name] = meta.group
by_group.setdefault(meta.group, set()).add(field)
self.oneof_group_by_field = by_field
self.oneof_field_by_group = by_group
self.init_default_gen()
self.init_cls_by_field()
def init_default_gen(self):
default_gen = {}
for field in dataclasses.fields(self.cls):
meta = FieldMetadata.get(field)
default_gen[field.name] = self.cls._get_field_default_gen(field, meta)
self.default_gen = default_gen
def init_cls_by_field(self):
field_cls = {}
for field in dataclasses.fields(self.cls):
meta = FieldMetadata.get(field)
if meta.proto_type == TYPE_MAP:
assert meta.map_types
kt = self.cls._cls_for(field, index=0)
vt = self.cls._cls_for(field, index=1)
Entry = dataclasses.make_dataclass(
"Entry",
[
("key", kt, dataclass_field(1, meta.map_types[0])),
("value", vt, dataclass_field(2, meta.map_types[1])),
],
bases=(Message,),
)
field_cls[field.name] = Entry
field_cls[field.name + ".value"] = vt
else:
field_cls[field.name] = self.cls._cls_for(field)
self.cls_by_field = field_cls
class Message(ABC):
"""
A protobuf message base class. Generated code will inherit from this and
register the message fields which get used by the serializers and parsers
to go between Python, binary and JSON protobuf message representations.
"""
_serialized_on_wire: bool
_unknown_fields: bytes
_group_map: Dict[str, dict]
def __post_init__(self) -> None:
# Keep track of whether every field was default
all_sentinel = True
# Set a default value for each field in the class after `__init__` has
# already been run.
group_map: Dict[str, dataclasses.Field] = {}
for field in dataclasses.fields(self):
meta = FieldMetadata.get(field)
if meta.group:
group_map.setdefault(meta.group)
if getattr(self, field.name) != PLACEHOLDER:
# Skip anything not set to the sentinel value
all_sentinel = False
if meta.group:
# This was set, so make it the selected value of the one-of.
group_map[meta.group] = field
continue
setattr(self, field.name, self._get_field_default(field, meta))
# Now that all the defaults are set, reset it!
self.__dict__["_serialized_on_wire"] = not all_sentinel
self.__dict__["_unknown_fields"] = b""
self.__dict__["_group_map"] = group_map
def __setattr__(self, attr: str, value: Any) -> None:
if attr != "_serialized_on_wire":
# Track when a field has been set.
self.__dict__["_serialized_on_wire"] = True
if hasattr(self, "_group_map"): # __post_init__ had already run
if attr in self._betterproto.oneof_group_by_field:
group = self._betterproto.oneof_group_by_field[attr]
for field in self._betterproto.oneof_field_by_group[group]:
if field.name == attr:
self._group_map[group] = field
else:
super().__setattr__(
field.name,
self._get_field_default(field, FieldMetadata.get(field)),
)
super().__setattr__(attr, value)
@property
def _betterproto(self):
"""
Lazy initialize metadata for each protobuf class.
It may be initialized multiple times in a multi-threaded environment,
but that won't affect the correctness.
"""
meta = getattr(self.__class__, "_betterproto_meta", None)
if not meta:
meta = ProtoClassMetadata(self.__class__)
self.__class__._betterproto_meta = meta
return meta
def __bytes__(self) -> bytes:
"""
Get the binary encoded Protobuf representation of this instance.
"""
output = b""
for field in dataclasses.fields(self):
meta = FieldMetadata.get(field)
value = getattr(self, field.name)
if value is None:
# Optional items should be skipped. This is used for the Google
# wrapper types.
continue
# Being selected in a a group means this field is the one that is
# currently set in a `oneof` group, so it must be serialized even
# if the value is the default zero value.
selected_in_group = False
if meta.group and self._group_map[meta.group] == field:
selected_in_group = True
serialize_empty = False
if isinstance(value, Message) and value._serialized_on_wire:
# Empty messages can still be sent on the wire if they were
# set (or received empty).
serialize_empty = True
if value == self._get_field_default(field, meta) and not (
selected_in_group or serialize_empty
):
# Default (zero) values are not serialized. Two exceptions are
# if this is the selected oneof item or if we know we have to
# serialize an empty message (i.e. zero value was explicitly
# set by the user).
continue
if isinstance(value, list):
if meta.proto_type in PACKED_TYPES:
# Packed lists look like a length-delimited field. First,
# preprocess/encode each value into a buffer and then
# treat it like a field of raw bytes.
buf = b""
for item in value:
buf += _preprocess_single(meta.proto_type, "", item)
output += _serialize_single(meta.number, TYPE_BYTES, buf)
else:
for item in value:
output += _serialize_single(
meta.number, meta.proto_type, item, wraps=meta.wraps or ""
)
elif isinstance(value, dict):
for k, v in value.items():
assert meta.map_types
sk = _serialize_single(1, meta.map_types[0], k)
sv = _serialize_single(2, meta.map_types[1], v)
output += _serialize_single(meta.number, meta.proto_type, sk + sv)
else:
output += _serialize_single(
meta.number,
meta.proto_type,
value,
serialize_empty=serialize_empty,
wraps=meta.wraps or "",
)
return output + self._unknown_fields
# For compatibility with other libraries
SerializeToString = __bytes__
@classmethod
def _type_hint(cls, field_name: str) -> Type:
module = inspect.getmodule(cls)
type_hints = get_type_hints(cls, vars(module))
return type_hints[field_name]
@classmethod
def _cls_for(cls, field: dataclasses.Field, index: int = 0) -> Type:
"""Get the message class for a field from the type hints."""
field_cls = cls._type_hint(field.name)
if hasattr(field_cls, "__args__") and index >= 0:
field_cls = field_cls.__args__[index]
return field_cls
def _get_field_default(self, field: dataclasses.Field, meta: FieldMetadata) -> Any:
return self._betterproto.default_gen[field.name]()
@classmethod
def _get_field_default_gen(
cls, field: dataclasses.Field, meta: FieldMetadata
) -> Any:
t = cls._type_hint(field.name)
if hasattr(t, "__origin__"):
if t.__origin__ in (dict, Dict):
# This is some kind of map (dict in Python).
return dict
elif t.__origin__ in (list, List):
# This is some kind of list (repeated) field.
return list
elif t.__origin__ == Union and t.__args__[1] == type(None):
# This is an optional (wrapped) field. For setting the default we
# really don't care what kind of field it is.
return type(None)
else:
return t
elif issubclass(t, Enum):
# Enums always default to zero.
return int
elif t == datetime:
# Offsets are relative to 1970-01-01T00:00:00Z
return datetime_default_gen
else:
# This is either a primitive scalar or another message type. Calling
# it should result in its zero value.
return t
def _postprocess_single(
self, wire_type: int, meta: FieldMetadata, field: dataclasses.Field, value: Any
) -> Any:
"""Adjusts values after parsing."""
if wire_type == WIRE_VARINT:
if meta.proto_type in [TYPE_INT32, TYPE_INT64]:
bits = int(meta.proto_type[3:])
value = value & ((1 << bits) - 1)
signbit = 1 << (bits - 1)
value = int((value ^ signbit) - signbit)
elif meta.proto_type in [TYPE_SINT32, TYPE_SINT64]:
# Undo zig-zag encoding
value = (value >> 1) ^ (-(value & 1))
elif meta.proto_type == TYPE_BOOL:
# Booleans use a varint encoding, so convert it to true/false.
value = value > 0
elif wire_type in [WIRE_FIXED_32, WIRE_FIXED_64]:
fmt = _pack_fmt(meta.proto_type)
value = struct.unpack(fmt, value)[0]
elif wire_type == WIRE_LEN_DELIM:
if meta.proto_type == TYPE_STRING:
value = value.decode("utf-8")
elif meta.proto_type == TYPE_MESSAGE:
cls = self._betterproto.cls_by_field[field.name]
if cls == datetime:
value = _Timestamp().parse(value).to_datetime()
elif cls == timedelta:
value = _Duration().parse(value).to_timedelta()
elif meta.wraps:
# This is a Google wrapper value message around a single
# scalar type.
value = _get_wrapper(meta.wraps)().parse(value).value
else:
value = cls().parse(value)
value._serialized_on_wire = True
elif meta.proto_type == TYPE_MAP:
value = self._betterproto.cls_by_field[field.name]().parse(value)
return value
def parse(self: T, data: bytes) -> T:
"""
Parse the binary encoded Protobuf into this message instance. This
returns the instance itself and is therefore assignable and chainable.
"""
fields = {f.metadata["betterproto"].number: f for f in dataclasses.fields(self)}
for parsed in parse_fields(data):
if parsed.number in fields:
field = fields[parsed.number]
meta = FieldMetadata.get(field)
value: Any
if (
parsed.wire_type == WIRE_LEN_DELIM
and meta.proto_type in PACKED_TYPES
):
# This is a packed repeated field.
pos = 0
value = []
while pos < len(parsed.value):
if meta.proto_type in ["float", "fixed32", "sfixed32"]:
decoded, pos = parsed.value[pos : pos + 4], pos + 4
wire_type = WIRE_FIXED_32
elif meta.proto_type in ["double", "fixed64", "sfixed64"]:
decoded, pos = parsed.value[pos : pos + 8], pos + 8
wire_type = WIRE_FIXED_64
else:
decoded, pos = decode_varint(parsed.value, pos)
wire_type = WIRE_VARINT
decoded = self._postprocess_single(
wire_type, meta, field, decoded
)
value.append(decoded)
else:
value = self._postprocess_single(
parsed.wire_type, meta, field, parsed.value
)
current = getattr(self, field.name)
if meta.proto_type == TYPE_MAP:
# Value represents a single key/value pair entry in the map.
current[value.key] = value.value
elif isinstance(current, list) and not isinstance(value, list):
current.append(value)
else:
setattr(self, field.name, value)
else:
self._unknown_fields += parsed.raw
return self
# For compatibility with other libraries.
@classmethod
def FromString(cls: Type[T], data: bytes) -> T:
return cls().parse(data)
def to_dict(
self, casing: Casing = Casing.CAMEL, include_default_values: bool = False
) -> dict:
"""
Returns a dict representation of this message instance which can be
used to serialize to e.g. JSON. Defaults to camel casing for
compatibility but can be set to other modes.
`include_default_values` can be set to `True` to include default
values of fields. E.g. an `int32` type field with `0` value will
not be in returned dict if `include_default_values` is set to
`False`.
"""
output: Dict[str, Any] = {}
for field in dataclasses.fields(self):
meta = FieldMetadata.get(field)
v = getattr(self, field.name)
cased_name = casing(field.name).rstrip("_") # type: ignore
if meta.proto_type == "message":
if isinstance(v, datetime):
if v != DATETIME_ZERO or include_default_values:
output[cased_name] = _Timestamp.timestamp_to_json(v)
elif isinstance(v, timedelta):
if v != timedelta(0) or include_default_values:
output[cased_name] = _Duration.delta_to_json(v)
elif meta.wraps:
if v is not None or include_default_values:
output[cased_name] = v
elif isinstance(v, list):
# Convert each item.
v = [i.to_dict(casing, include_default_values) for i in v]
if v or include_default_values:
output[cased_name] = v
else:
if v._serialized_on_wire or include_default_values:
output[cased_name] = v.to_dict(casing, include_default_values)
elif meta.proto_type == "map":
for k in v:
if hasattr(v[k], "to_dict"):
v[k] = v[k].to_dict(casing, include_default_values)
if v or include_default_values:
output[cased_name] = v
elif v != self._get_field_default(field, meta) or include_default_values:
if meta.proto_type in INT_64_TYPES:
if isinstance(v, list):
output[cased_name] = [str(n) for n in v]
else:
output[cased_name] = str(v)
elif meta.proto_type == TYPE_BYTES:
if isinstance(v, list):
output[cased_name] = [b64encode(b).decode("utf8") for b in v]
else:
output[cased_name] = b64encode(v).decode("utf8")
elif meta.proto_type == TYPE_ENUM:
enum_values = list(
self._betterproto.cls_by_field[field.name]
) # type: ignore
if isinstance(v, list):
output[cased_name] = [enum_values[e].name for e in v]
else:
output[cased_name] = enum_values[v].name
else:
output[cased_name] = v
return output
def from_dict(self: T, value: dict) -> T:
"""
Parse the key/value pairs in `value` into this message instance. This
returns the instance itself and is therefore assignable and chainable.
"""
self._serialized_on_wire = True
fields_by_name = {f.name: f for f in dataclasses.fields(self)}
for key in value:
snake_cased = safe_snake_case(key)
if snake_cased in fields_by_name:
field = fields_by_name[snake_cased]
meta = FieldMetadata.get(field)
if value[key] is not None:
if meta.proto_type == "message":
v = getattr(self, field.name)
if isinstance(v, list):
cls = self._betterproto.cls_by_field[field.name]
for i in range(len(value[key])):
v.append(cls().from_dict(value[key][i]))
elif isinstance(v, datetime):
v = datetime.fromisoformat(
value[key].replace("Z", "+00:00")
)
setattr(self, field.name, v)
elif isinstance(v, timedelta):
v = timedelta(seconds=float(value[key][:-1]))
setattr(self, field.name, v)
elif meta.wraps:
setattr(self, field.name, value[key])
else:
v.from_dict(value[key])
elif meta.map_types and meta.map_types[1] == TYPE_MESSAGE:
v = getattr(self, field.name)
cls = self._betterproto.cls_by_field[field.name + ".value"]
for k in value[key]:
v[k] = cls().from_dict(value[key][k])
else:
v = value[key]
if meta.proto_type in INT_64_TYPES:
if isinstance(value[key], list):
v = [int(n) for n in value[key]]
else:
v = int(value[key])
elif meta.proto_type == TYPE_BYTES:
if isinstance(value[key], list):
v = [b64decode(n) for n in value[key]]
else:
v = b64decode(value[key])
elif meta.proto_type == TYPE_ENUM:
enum_cls = self._betterproto.cls_by_field[field.name]
if isinstance(v, list):
v = [enum_cls.from_string(e) for e in v]
elif isinstance(v, str):
v = enum_cls.from_string(v)
if v is not None:
setattr(self, field.name, v)
return self
def to_json(self, indent: Union[None, int, str] = None) -> str:
"""Returns the encoded JSON representation of this message instance."""
return json.dumps(self.to_dict(), indent=indent)
def from_json(self: T, value: Union[str, bytes]) -> T:
"""
Parse the key/value pairs in `value` into this message instance. This
returns the instance itself and is therefore assignable and chainable.
"""
return self.from_dict(json.loads(value))
def serialized_on_wire(message: Message) -> bool:
"""
True if this message was or should be serialized on the wire. This can
be used to detect presence (e.g. optional wrapper message) and is used
internally during parsing/serialization.
"""
return message._serialized_on_wire
def which_one_of(message: Message, group_name: str) -> Tuple[str, Any]:
"""Return the name and value of a message's one-of field group."""
field = message._group_map.get(group_name)
if not field:
return ("", None)
return (field.name, getattr(message, field.name))
@dataclasses.dataclass
class _Duration(Message):
# Signed seconds of the span of time. Must be from -315,576,000,000 to
# +315,576,000,000 inclusive. Note: these bounds are computed from: 60
# sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
seconds: int = int64_field(1)
# Signed fractions of a second at nanosecond resolution of the span of time.
# Durations less than one second are represented with a 0 `seconds` field and
# a positive or negative `nanos` field. For durations of one second or more,
# a non-zero value for the `nanos` field must be of the same sign as the
# `seconds` field. Must be from -999,999,999 to +999,999,999 inclusive.
nanos: int = int32_field(2)
def to_timedelta(self) -> timedelta:
return timedelta(seconds=self.seconds, microseconds=self.nanos / 1e3)
@staticmethod
def delta_to_json(delta: timedelta) -> str:
parts = str(delta.total_seconds()).split(".")
if len(parts) > 1:
while len(parts[1]) not in [3, 6, 9]:
parts[1] = parts[1] + "0"
return ".".join(parts) + "s"
@dataclasses.dataclass
class _Timestamp(Message):
# Represents seconds of UTC time since Unix epoch 1970-01-01T00:00:00Z. Must
# be from 0001-01-01T00:00:00Z to 9999-12-31T23:59:59Z inclusive.
seconds: int = int64_field(1)
# Non-negative fractions of a second at nanosecond resolution. Negative
# second values with fractions must still have non-negative nanos values that
# count forward in time. Must be from 0 to 999,999,999 inclusive.
nanos: int = int32_field(2)
def to_datetime(self) -> datetime:
ts = self.seconds + (self.nanos / 1e9)
return datetime.fromtimestamp(ts, tz=timezone.utc)
@staticmethod
def timestamp_to_json(dt: datetime) -> str:
nanos = dt.microsecond * 1e3
copy = dt.replace(microsecond=0, tzinfo=None)
result = copy.isoformat()
if (nanos % 1e9) == 0:
# If there are 0 fractional digits, the fractional
# point '.' should be omitted when serializing.
return result + "Z"
if (nanos % 1e6) == 0:
# Serialize 3 fractional digits.
return result + ".%03dZ" % (nanos / 1e6)
if (nanos % 1e3) == 0:
# Serialize 6 fractional digits.
return result + ".%06dZ" % (nanos / 1e3)
# Serialize 9 fractional digits.
return result + ".%09dZ" % nanos
class _WrappedMessage(Message):
"""
Google protobuf wrapper types base class. JSON representation is just the
value itself.
"""
value: Any
def to_dict(self, casing: Casing = Casing.CAMEL) -> Any:
return self.value
def from_dict(self: T, value: Any) -> T:
if value is not None:
self.value = value
return self
@dataclasses.dataclass
class _BoolValue(_WrappedMessage):
value: bool = bool_field(1)
@dataclasses.dataclass
class _Int32Value(_WrappedMessage):
value: int = int32_field(1)
@dataclasses.dataclass
class _UInt32Value(_WrappedMessage):
value: int = uint32_field(1)
@dataclasses.dataclass
class _Int64Value(_WrappedMessage):
value: int = int64_field(1)
@dataclasses.dataclass
class _UInt64Value(_WrappedMessage):
value: int = uint64_field(1)
@dataclasses.dataclass
class _FloatValue(_WrappedMessage):
value: float = float_field(1)
@dataclasses.dataclass
class _DoubleValue(_WrappedMessage):
value: float = double_field(1)
@dataclasses.dataclass
class _StringValue(_WrappedMessage):
value: str = string_field(1)
@dataclasses.dataclass
class _BytesValue(_WrappedMessage):
value: bytes = bytes_field(1)
def _get_wrapper(proto_type: str) -> Type:
"""Get the wrapper message class for a wrapped type."""
return {
TYPE_BOOL: _BoolValue,
TYPE_INT32: _Int32Value,
TYPE_UINT32: _UInt32Value,
TYPE_INT64: _Int64Value,
TYPE_UINT64: _UInt64Value,
TYPE_FLOAT: _FloatValue,
TYPE_DOUBLE: _DoubleValue,
TYPE_STRING: _StringValue,
TYPE_BYTES: _BytesValue,
}[proto_type]
_Value = Union[str, bytes]
_MetadataLike = Union[Mapping[str, _Value], Collection[Tuple[str, _Value]]]
class ServiceStub(ABC):
"""
Base class for async gRPC service stubs.
"""
def __init__(
self,
channel: "Channel",
*,
timeout: Optional[float] = None,
deadline: Optional["Deadline"] = None,
metadata: Optional[_MetadataLike] = None,
) -> None:
self.channel = channel
self.timeout = timeout
self.deadline = deadline
self.metadata = metadata
def __resolve_request_kwargs(
self,
timeout: Optional[float],
deadline: Optional["Deadline"],
metadata: Optional[_MetadataLike],
):
return {
"timeout": self.timeout if timeout is None else timeout,
"deadline": self.deadline if deadline is None else deadline,
"metadata": self.metadata if metadata is None else metadata,
}
async def _unary_unary(
self,
route: str,
request: "IProtoMessage",
response_type: Type[T],
*,
timeout: Optional[float] = None,
deadline: Optional["Deadline"] = None,
metadata: Optional[_MetadataLike] = None,
) -> T:
"""Make a unary request and return the response."""
async with self.channel.request(
route,
grpclib.const.Cardinality.UNARY_UNARY,
type(request),
response_type,
**self.__resolve_request_kwargs(timeout, deadline, metadata),
) as stream:
await stream.send_message(request, end=True)
response = await stream.recv_message()
assert response is not None
return response
async def _unary_stream(
self,
route: str,
request: "IProtoMessage",
response_type: Type[T],
*,
timeout: Optional[float] = None,
deadline: Optional["Deadline"] = None,
metadata: Optional[_MetadataLike] = None,
) -> AsyncGenerator[T, None]:
"""Make a unary request and return the stream response iterator."""
async with self.channel.request(
route,
grpclib.const.Cardinality.UNARY_STREAM,
type(request),
response_type,
**self.__resolve_request_kwargs(timeout, deadline, metadata),
) as stream:
await stream.send_message(request, end=True)
async for message in stream:
yield message