#-----------------------------------------------------------------------------
# Copyright (c) Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
""" Serialization and deserialization utilities. """
#-----------------------------------------------------------------------------
# Boilerplate
#-----------------------------------------------------------------------------
from __future__ import annotations
import logging # isort:skip
log = logging.getLogger(__name__)
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# Standard library imports
import base64
import datetime as dt
import sys
from array import array as TypedArray
from math import isinf, isnan
from types import SimpleNamespace
from typing import (
TYPE_CHECKING,
Any,
Callable,
ClassVar,
Generic,
Literal,
NoReturn,
Sequence,
TypeAlias,
TypedDict,
TypeVar,
cast,
)
# External imports
import numpy as np
# Bokeh imports
from ..util.dataclasses import (
Unspecified,
dataclass,
entries,
is_dataclass,
)
from ..util.dependencies import uses_pandas
from ..util.serialization import (
array_encoding_disabled,
convert_datetime_type,
convert_timedelta_type,
is_datetime_type,
is_timedelta_type,
make_id,
transform_array,
transform_series,
)
from ..util.warnings import BokehUserWarning, warn
from .types import ID
if TYPE_CHECKING:
import numpy.typing as npt
from typing_extensions import NotRequired
from ..core.has_props import Setter
from ..model import Model
#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------
__all__ = (
"Buffer",
"DeserializationError",
"Deserializer",
"Serializable",
"SerializationError",
"Serializer",
)
_MAX_SAFE_INT = 2**53 - 1
#-----------------------------------------------------------------------------
# General API
#-----------------------------------------------------------------------------
AnyRep: TypeAlias = Any
class Ref(TypedDict):
id: ID
class RefRep(TypedDict):
type: Literal["ref"]
id: ID
class SymbolRep(TypedDict):
type: Literal["symbol"]
name: str
class NumberRep(TypedDict):
type: Literal["number"]
value: Literal["nan", "-inf", "+inf"] | float
class ArrayRep(TypedDict):
type: Literal["array"]
entries: NotRequired[list[AnyRep]]
ArrayRepLike: TypeAlias = ArrayRep | list[AnyRep]
class SetRep(TypedDict):
type: Literal["set"]
entries: NotRequired[list[AnyRep]]
class MapRep(TypedDict):
type: Literal["map"]
entries: NotRequired[list[tuple[AnyRep, AnyRep]]]
class BytesRep(TypedDict):
type: Literal["bytes"]
data: Buffer | Ref | str
class SliceRep(TypedDict):
type: Literal["slice"]
start: int | None
stop: int | None
step: int | None
class ObjectRep(TypedDict):
type: Literal["object"]
name: str
attributes: NotRequired[dict[str, AnyRep]]
class ObjectRefRep(TypedDict):
type: Literal["object"]
name: str
id: ID
attributes: NotRequired[dict[str, AnyRep]]
ModelRep = ObjectRefRep
ByteOrder: TypeAlias = Literal["little", "big"]
DataType: TypeAlias = Literal["uint8", "int8", "uint16", "int16", "uint32", "int32", "float32", "float64"] # "uint64", "int64"
NDDataType: TypeAlias = Literal["bool"] | DataType | Literal["object"]
class TypedArrayRep(TypedDict):
type: Literal["typed_array"]
array: BytesRep
order: ByteOrder
dtype: DataType
class NDArrayRep(TypedDict):
type: Literal["ndarray"]
array: BytesRep | ArrayRepLike
order: ByteOrder
dtype: NDDataType
shape: list[int]
[docs]
@dataclass
class Buffer:
id: ID
data: bytes | memoryview
@property
def ref(self) -> Ref:
return Ref(id=self.id)
def to_bytes(self) -> bytes:
return self.data.tobytes() if isinstance(self.data, memoryview) else self.data
def to_base64(self) -> str:
return base64.b64encode(self.data).decode("utf-8")
T = TypeVar("T")
[docs]
@dataclass
class Serialized(Generic[T]):
content: T
buffers: list[Buffer] | None = None
Encoder: TypeAlias = Callable[[Any, "Serializer"], AnyRep]
Decoder: TypeAlias = Callable[[AnyRep, "Deserializer"], Any]
[docs]
class SerializationError(ValueError):
pass
[docs]
class Serializable:
""" A mixin for making a type serializable. """
def to_serializable(self, serializer: Serializer) -> AnyRep:
""" Converts this object to a serializable representation. """
raise NotImplementedError()
ObjID = int
[docs]
class Serializer:
""" Convert built-in and custom types into serializable representations.
Not all built-in types are supported (e.g., decimal.Decimal due to
lacking support for fixed point arithmetic in JavaScript).
"""
_encoders: ClassVar[dict[type[Any], Encoder]] = {}
@classmethod
def register(cls, type: type[Any], encoder: Encoder) -> None:
assert type not in cls._encoders, f"'{type} is already registered"
cls._encoders[type] = encoder
_references: dict[ObjID, Ref]
_deferred: bool
_circular: dict[ObjID, Any]
_buffers: list[Buffer]
def __init__(self, *, references: set[Model] = set(), deferred: bool = True) -> None:
self._references = {id(obj): obj.ref for obj in references}
self._deferred = deferred
self._circular = {}
self._buffers = []
def has_ref(self, obj: Any) -> bool:
return id(obj) in self._references
def add_ref(self, obj: Any, ref: Ref) -> None:
assert id(obj) not in self._references
self._references[id(obj)] = ref
def get_ref(self, obj: Any) -> Ref | None:
return self._references.get(id(obj))
@property
def buffers(self) -> list[Buffer]:
return list(self._buffers)
def serialize(self, obj: Any) -> Serialized[Any]:
return Serialized(self.encode(obj), self.buffers)
def encode(self, obj: Any) -> AnyRep:
ref = self.get_ref(obj)
if ref is not None:
return ref
ident = id(obj)
if ident in self._circular:
self.error("circular reference")
self._circular[ident] = obj
try:
return self._encode(obj)
finally:
del self._circular[ident]
def encode_struct(self, **fields: Any) -> dict[str, AnyRep]:
return {key: self.encode(val) for key, val in fields.items() if val is not Unspecified}
def _encode(self, obj: Any) -> AnyRep:
if isinstance(obj, Serializable):
return obj.to_serializable(self)
elif (encoder := self._encoders.get(type(obj))) is not None:
return encoder(obj, self)
elif obj is None:
return None
elif isinstance(obj, bool):
return self._encode_bool(obj)
elif isinstance(obj, str):
return self._encode_str(obj)
elif isinstance(obj, int):
return self._encode_int(obj)
elif isinstance(obj, float):
return self._encode_float(obj)
elif isinstance(obj, tuple):
return self._encode_tuple(obj)
elif isinstance(obj, list):
return self._encode_list(obj)
elif isinstance(obj, set):
return self._encode_set(obj)
elif isinstance(obj, dict):
return self._encode_dict(obj)
elif isinstance(obj, SimpleNamespace):
return self._encode_struct(obj)
elif isinstance(obj, bytes):
return self._encode_bytes(obj)
elif isinstance(obj, slice):
return self._encode_slice(obj)
elif isinstance(obj, TypedArray):
return self._encode_typed_array(obj)
elif isinstance(obj, np.ndarray):
if obj.shape != ():
return self._encode_ndarray(obj)
else:
return self._encode(obj.item())
elif is_dataclass(obj):
return self._encode_dataclass(obj)
else:
return self._encode_other(obj)
def _encode_bool(self, obj: bool) -> AnyRep:
return obj
def _encode_str(self, obj: str) -> AnyRep:
return obj
def _encode_int(self, obj: int) -> AnyRep:
if -_MAX_SAFE_INT < obj <= _MAX_SAFE_INT:
return obj
else:
warn("out of range integer may result in loss of precision", BokehUserWarning)
return self._encode_float(float(obj))
def _encode_float(self, obj: float) -> NumberRep | float:
if isnan(obj):
return NumberRep(type="number", value="nan")
elif isinf(obj):
return NumberRep(type="number", value="-inf" if obj < 0 else "+inf")
else:
return obj
def _encode_tuple(self, obj: tuple[Any, ...]) -> ArrayRepLike:
return self._encode_list(list(obj))
def _encode_list(self, obj: list[Any]) -> ArrayRepLike:
return [self.encode(item) for item in obj]
def _encode_set(self, obj: set[Any]) -> SetRep:
if len(obj) == 0:
return SetRep(type="set")
else:
return SetRep(
type="set",
entries=[self.encode(entry) for entry in obj],
)
def _encode_dict(self, obj: dict[Any, Any]) -> MapRep:
if len(obj) == 0:
result = MapRep(type="map")
else:
result = MapRep(
type="map",
entries=[(self.encode(key), self.encode(val)) for key, val in obj.items()],
)
return result
def _encode_struct(self, obj: SimpleNamespace) -> MapRep:
return self._encode_dict(obj.__dict__)
def _encode_dataclass(self, obj: Any) -> ObjectRep:
cls = type(obj)
module = cls.__module__
name = cls.__qualname__.replace("<locals>.", "")
rep = ObjectRep(
type="object",
name=f"{module}.{name}",
)
attributes = list(entries(obj))
if attributes:
rep["attributes"] = {key: self.encode(val) for key, val in attributes}
return rep
def _encode_bytes(self, obj: bytes | memoryview) -> BytesRep:
buffer = Buffer(make_id(), obj)
data: Buffer | str
if self._deferred:
self._buffers.append(buffer)
data = buffer
else:
data = buffer.to_base64()
return BytesRep(type="bytes", data=data)
def _encode_slice(self, obj: slice) -> SliceRep:
return SliceRep(
type="slice",
start=self.encode(obj.start),
stop=self.encode(obj.stop),
step=self.encode(obj.step),
)
def _encode_typed_array(self, obj: TypedArray[Any]) -> TypedArrayRep:
array = self._encode_bytes(memoryview(obj))
typecode = obj.typecode
itemsize = obj.itemsize
def dtype() -> DataType:
match typecode:
case "f":
return "float32"
case "d":
return "float64"
case "B" | "H" | "I" | "L" | "Q":
match obj.itemsize:
case 1: return "uint8"
case 2: return "uint16"
case 4: return "uint32"
#case 8: return "uint64"
case "b" | "h" | "i" | "l" | "q":
match obj.itemsize:
case 1: return "int8"
case 2: return "int16"
case 4: return "int32"
#case 8: return "int64"
self.error(f"can't serialize array with items of type '{typecode}@{itemsize}'")
return TypedArrayRep(
type="typed_array",
array=array,
order=sys.byteorder,
dtype=dtype(),
)
def _encode_ndarray(self, obj: npt.NDArray[Any]) -> NDArrayRep:
array = transform_array(obj)
data: ArrayRepLike | BytesRep
dtype: NDDataType
if array_encoding_disabled(array):
data = self._encode_list(array.flatten().tolist())
dtype = "object"
else:
data = self._encode_bytes(array.data)
dtype = cast(NDDataType, array.dtype.name)
return NDArrayRep(
type="ndarray",
array=data,
shape=list(array.shape),
dtype=dtype,
order=sys.byteorder,
)
def _encode_other(self, obj: Any) -> AnyRep:
# date/time values that get serialized as milliseconds
if is_datetime_type(obj):
return convert_datetime_type(obj)
if is_timedelta_type(obj):
return convert_timedelta_type(obj)
if isinstance(obj, dt.date):
return obj.isoformat()
# NumPy scalars
if np.issubdtype(type(obj), np.floating):
return self._encode_float(float(obj))
if np.issubdtype(type(obj), np.integer):
return self._encode_int(int(obj))
if np.issubdtype(type(obj), np.bool_):
return self._encode_bool(bool(obj))
# avoid importing pandas here unless it is actually in use
if uses_pandas(obj):
import pandas as pd
if isinstance(obj, pd.Series | pd.Index | pd.api.extensions.ExtensionArray):
return self._encode_ndarray(transform_series(obj))
elif obj is pd.NA:
return None
# handle array libraries that support conversion to a numpy array (e.g. polars, PyTorch)
if hasattr(obj, "__array__") and isinstance(arr := obj.__array__(), np.ndarray):
return self._encode_ndarray(arr)
self.error(f"can't serialize {type(obj)}")
def error(self, message: str) -> NoReturn:
raise SerializationError(message)
[docs]
class DeserializationError(ValueError):
pass
class UnknownReferenceError(DeserializationError):
def __init__(self, id: ID) -> None:
super().__init__(f"can't resolve reference '{id}'")
self.id = id
[docs]
class Deserializer:
""" Convert from serializable representations to built-in and custom types. """
_decoders: ClassVar[dict[str, Decoder]] = {}
@classmethod
def register(cls, type: str, decoder: Decoder) -> None:
assert type not in cls._decoders, f"'{type} is already registered"
cls._decoders[type] = decoder
_references: dict[ID, Model]
_setter: Setter | None
_decoding: bool
_buffers: dict[ID, Buffer]
def __init__(self, references: Sequence[Model] | None = None, *, setter: Setter | None = None):
self._references = {obj.id: obj for obj in references or []}
self._setter = setter
self._decoding = False
self._buffers = {}
def has_ref(self, obj: Model) -> bool:
return obj.id in self._references
def deserialize(self, obj: Any | Serialized[Any]) -> Any:
if isinstance(obj, Serialized):
return self.decode(obj.content, obj.buffers)
else:
return self.decode(obj)
def decode(self, obj: AnyRep, buffers: list[Buffer] | None = None) -> Any:
if buffers is not None:
for buffer in buffers:
self._buffers[buffer.id] = buffer
if self._decoding:
return self._decode(obj)
self._decoding = True
try:
return self._decode(obj)
finally:
self._buffers.clear()
self._decoding = False
def _decode(self, obj: AnyRep) -> Any:
if isinstance(obj, dict):
if "type" in obj:
match obj["type"]:
case type if type in self._decoders:
return self._decoders[type](obj, self)
case "ref":
return self._decode_ref(cast(Ref, obj))
case "symbol":
return self._decode_symbol(cast(SymbolRep, obj))
case "number":
return self._decode_number(cast(NumberRep, obj))
case "array":
return self._decode_array(cast(ArrayRep, obj))
case "set":
return self._decode_set(cast(SetRep, obj))
case "map":
return self._decode_map(cast(MapRep, obj))
case "bytes":
return self._decode_bytes(cast(BytesRep, obj))
case "slice":
return self._decode_slice(cast(SliceRep, obj))
case "typed_array":
return self._decode_typed_array(cast(TypedArrayRep, obj))
case "ndarray":
return self._decode_ndarray(cast(NDArrayRep, obj))
case "object":
if "id" in obj:
return self._decode_object_ref(cast(ObjectRefRep, obj))
else:
return self._decode_object(cast(ObjectRep, obj))
case type:
self.error(f"unable to decode an object of type '{type}'")
elif "id" in obj:
return self._decode_ref(cast(Ref, obj))
else:
return {key: self._decode(val) for key, val in obj.items()}
elif isinstance(obj, list):
return [self._decode(entry) for entry in obj]
else:
return obj
def _decode_ref(self, obj: Ref) -> Model:
id = obj["id"]
instance = self._references.get(id)
if instance is not None:
return instance
else:
self.error(UnknownReferenceError(id))
def _decode_symbol(self, obj: SymbolRep) -> float:
name = obj["name"]
self.error(f"can't resolve named symbol '{name}'") # TODO: implement symbol resolution
def _decode_number(self, obj: NumberRep) -> float:
value = obj["value"]
return float(value) if isinstance(value, str) else value
def _decode_array(self, obj: ArrayRep) -> list[Any]:
entries = obj.get("entries", [])
return [ self._decode(entry) for entry in entries ]
def _decode_set(self, obj: SetRep) -> set[Any]:
entries = obj.get("entries", [])
return { self._decode(entry) for entry in entries }
def _decode_map(self, obj: MapRep) -> dict[Any, Any]:
entries = obj.get("entries", [])
return { self._decode(key): self._decode(val) for key, val in entries }
def _decode_bytes(self, obj: BytesRep) -> bytes:
data = obj["data"]
if isinstance(data, str):
return base64.b64decode(data)
elif isinstance(data, Buffer):
buffer = data # in case of decode(encode(obj))
else:
id = data["id"]
if id in self._buffers:
buffer = self._buffers[id]
else:
self.error(f"can't resolve buffer '{id}'")
return buffer.data
def _decode_slice(self, obj: SliceRep) -> slice:
start = self._decode(obj["start"])
stop = self._decode(obj["stop"])
step = self._decode(obj["step"])
return slice(start, stop, step)
def _decode_typed_array(self, obj: TypedArrayRep) -> TypedArray[Any]:
array = obj["array"]
order = obj["order"]
dtype = obj["dtype"]
data = self._decode(array)
dtype_to_typecode = dict(
uint8="B",
int8="b",
uint16="H",
int16="h",
uint32="I",
int32="i",
#uint64="Q",
#int64="q",
float32="f",
float64="d",
)
typecode = dtype_to_typecode.get(dtype)
if typecode is None:
self.error(f"unsupported dtype '{dtype}'")
typed_array: TypedArray[Any] = TypedArray(typecode, data)
if order != sys.byteorder:
typed_array.byteswap()
return typed_array
def _decode_ndarray(self, obj: NDArrayRep) -> npt.NDArray[Any]:
array = obj["array"]
order = obj["order"]
dtype = obj["dtype"]
shape = obj["shape"]
decoded = self._decode(array)
ndarray: npt.NDArray[Any]
if isinstance(decoded, bytes):
ndarray = np.copy(np.frombuffer(decoded, dtype=dtype))
if order != sys.byteorder:
ndarray.byteswap(inplace=True)
else:
ndarray = np.array(decoded, dtype=dtype)
if len(shape) > 1:
ndarray = ndarray.reshape(shape)
return ndarray
def _decode_object(self, obj: ObjectRep) -> object:
raise NotImplementedError()
def _decode_object_ref(self, obj: ObjectRefRep) -> Model:
id = obj["id"]
instance = self._references.get(id)
if instance is not None:
warn(f"reference already known '{id}'", BokehUserWarning)
return instance
name = obj["name"]
attributes = obj.get("attributes")
cls = self._resolve_type(name)
instance = cls.__new__(cls, id=id)
if instance is None:
self.error(f"can't instantiate {name}(id={id})")
self._references[instance.id] = instance
# We want to avoid any Model specific initialization that happens with
# Slider(...) when reconstituting from JSON, but we do need to perform
# general HasProps machinery that sets properties, so call it explicitly
if not instance._initialized:
from .has_props import HasProps
HasProps.__init__(instance)
if attributes is not None:
decoded_attributes = {key: self._decode(val) for key, val in attributes.items()}
for key, val in decoded_attributes.items():
instance.set_from_json(key, val, setter=self._setter)
return instance
def _resolve_type(self, type: str) -> type[Model]:
from ..model import Model
cls = Model.model_class_reverse_map.get(type)
if cls is not None:
if issubclass(cls, Model):
return cls
else:
self.error(f"object of type '{type}' is not a subclass of 'Model'")
else:
if type == "Figure":
from ..plotting import figure
return figure # XXX: helps with push_session(); this needs a better resolution scheme
else:
self.error(f"can't resolve type '{type}'")
def error(self, error: str | DeserializationError) -> NoReturn:
if isinstance(error, str):
raise DeserializationError(error)
else:
raise error
#-----------------------------------------------------------------------------
# Dev API
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Private API
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------
