ntorres
/
tractor
forked from goodboy/tractor
1
0
Fork 0
Code Pull Requests Activity
tractor/tractor/msg/_codec.py

887 lines
26 KiB
Python
Raw Blame History

# tractor: structured concurrent "actors".
# Copyright 2018-eternity Tyler Goodlet.
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
'''
IPC msg interchange codec management.
Supported backend libs:
- `msgspec.msgpack`
ToDo: backends we prolly should offer:
- see project/lib list throughout GH issue discussion comments:
https://github.com/goodboy/tractor/issues/196
- `capnproto`: https://capnproto.org/rpc.html
- https://capnproto.org/language.html#language-reference
'''
from __future__ import annotations
from contextlib import (
contextmanager as cm,
)
from contextvars import (
ContextVar,
Token,
)
import textwrap
from typing import (
Any,
Callable,
Protocol,
Type,
TYPE_CHECKING,
TypeVar,
Union,
)
from types import ModuleType
import msgspec
from msgspec import (
msgpack,
Raw,
)
# TODO: see notes below from @mikenerone..
# from tricycle import TreeVar
from tractor.msg.pretty_struct import Struct
from tractor.msg.types import (
mk_msg_spec,
MsgType,
PayloadMsg,
)
from tractor.log import get_logger
if TYPE_CHECKING:
from tractor._context import Context
log = get_logger(__name__)
# TODO: unify with `MsgCodec` by making `._dec` part this?
class MsgDec(Struct):
'''
An IPC msg (payload) decoder.
Normally used to decode only a payload: `MsgType.pld:
PayloadT` field before delivery to IPC consumer code.
'''
_dec: msgpack.Decoder
# _ext_types_box: Struct|None = None
@property
def dec(self) -> msgpack.Decoder:
return self._dec
def __repr__(self) -> str:
speclines: str = self.spec_str
# in multi-typed spec case we stick the list
# all on newlines after the |__pld_spec__:,
# OW it's prolly single type spec-value
# so just leave it on same line.
if '\n' in speclines:
speclines: str = '\n' + textwrap.indent(
speclines,
prefix=' '*3,
)
body: str = textwrap.indent(
f'|_dec_hook: {self.dec.dec_hook}\n'
f'|__pld_spec__: {speclines}\n',
prefix=' '*2,
)
return (
f'<{type(self).__name__}(\n'
f'{body}'
')>'
)
# struct type unions
# https://jcristharif.com/msgspec/structs.html#tagged-unions
#
# ^-TODO-^: make a wrapper type for this such that alt
# backends can be represented easily without a `Union` needed,
# AND so that we have better support for wire transport.
#
# -[ ] maybe `FieldSpec` is a good name since msg-spec
# better applies to a `MsgType[FieldSpec]`?
#
# -[ ] both as part of the `.open_context()` call AND as part of the
# immediate ack-reponse (see similar below)
# we should do spec matching and fail if anything is awry?
#
# -[ ] eventually spec should be generated/parsed from the
# type-annots as # desired in GH issue:
# https://github.com/goodboy/tractor/issues/365
#
# -[ ] semantics of the mismatch case
# - when caller-callee specs we should raise
# a `MsgTypeError` or `MsgSpecError` or similar?
#
# -[ ] wrapper types for both spec types such that we can easily
# IPC transport them?
# - `TypeSpec: Union[Type]`
# * also a `.__contains__()` for doing `None in
# TypeSpec[None|int]` since rn you need to do it on
# `.__args__` for unions..
# - `MsgSpec: Union[MsgType]
#
# -[ ] auto-genning this from new (in 3.12) type parameter lists Bo
# |_ https://docs.python.org/3/reference/compound_stmts.html#type-params
# |_ historical pep 695: https://peps.python.org/pep-0695/
# |_ full lang spec: https://typing.readthedocs.io/en/latest/spec/
# |_ on annotation scopes:
# https://docs.python.org/3/reference/executionmodel.html#annotation-scopes
# |_ 3.13 will have subscriptable funcs Bo
# https://peps.python.org/pep-0718/
@property
def spec(self) -> Union[Type[Struct]]:
# NOTE: defined and applied inside `mk_codec()`
return self._dec.type
# no difference, as compared to a `MsgCodec` which defines the
# `MsgType.pld: PayloadT` part of its spec separately
pld_spec = spec
# TODO: would get moved into `FieldSpec.__str__()` right?
@property
def spec_str(self) -> str:
return pformat_msgspec(
codec=self,
join_char='|',
)
pld_spec_str = spec_str
def decode(
self,
raw: Raw|bytes,
) -> Any:
return self._dec.decode(raw)
@property
def hook(self) -> Callable|None:
return self._dec.dec_hook
def mk_dec(
spec: Union[Type[Struct]]|Type|None,
# NOTE, required for ad-hoc type extensions to the underlying
# serialization proto (which is default `msgpack`),
# https://jcristharif.com/msgspec/extending.html#mapping-to-from-native-types
dec_hook: Callable|None = None,
ext_types: list[Type]|None = None,
) -> MsgDec:
'''
Create an IPC msg decoder, a slightly higher level wrapper around
a `msgspec.msgpack.Decoder` which provides,
- easier introspection of the underlying type spec via
the `.spec` and `.spec_str` attrs,
- `.hook` access to the `Decoder.dec_hook()`,
- automatic custom extension-types decode support when
`dec_hook()` is provided such that any `PayloadMsg.pld` tagged
as a type from from `ext_types` (presuming the `MsgCodec.encode()` also used
a `.enc_hook()`) is processed and constructed by a `PldRx` implicitily.
NOTE, as mentioned a `MsgDec` is normally used for `PayloadMsg.pld: PayloadT` field
decoding inside an IPC-ctx-oriented `PldRx`.
'''
if (
spec is None
and
ext_types is None
):
raise TypeError(
f'MIssing type-`spec` for msg decoder!\n'
f'\n'
f'`spec=None` is **only** permitted is if custom extension types '
f'are provided via `ext_types`, meaning it must be non-`None`.\n'
f'\n'
f'In this case it is presumed that only the `ext_types`, '
f'which much be handled by a paired `dec_hook()`, '
f'will be permitted within the payload type-`spec`!\n'
f'\n'
f'spec = {spec!r}\n'
f'dec_hook = {dec_hook!r}\n'
f'ext_types = {ext_types!r}\n'
)
if dec_hook:
if ext_types is None:
raise TypeError(
f'If extending the serializable types with a custom decode hook (`dec_hook()`), '
f'you must also provide the expected type set that the hook will handle '
f'via a `ext_types: Union[Type]|None = None` argument!\n'
f'\n'
f'dec_hook = {dec_hook!r}\n'
f'ext_types = {ext_types!r}\n'
)
# XXX, i *thought* we would require a boxing struct as per docs,
# https://jcristharif.com/msgspec/extending.html#mapping-to-from-native-types
# |_ see comment,
# > Note that typed deserialization is required for
# > successful roundtripping here, so we pass `MyMessage` to
# > `Decoder`.
#
# BUT, turns out as long as you spec a union with `Raw` it
# will work? kk B)
#
# maybe_box_struct = mk_boxed_ext_struct(ext_types)
spec = Raw | Union[*ext_types]
return MsgDec(
_dec=msgpack.Decoder(
type=spec, # like `MsgType[Any]`
dec_hook=dec_hook,
),
)
# TODO? remove since didn't end up needing this?
def mk_boxed_ext_struct(
ext_types: list[Type],
) -> Struct:
# NOTE, originally was to wrap non-msgpack-supported "extension
# types" in a field-typed boxing struct, see notes around the
# `dec_hook()` branch in `mk_dec()`.
ext_types_union = Union[*ext_types]
repr_ext_types_union: str = (
str(ext_types_union)
or
"|".join(ext_types)
)
BoxedExtType = msgspec.defstruct(
f'BoxedExts[{repr_ext_types_union}]',
fields=[
('boxed', ext_types_union),
],
)
return BoxedExtType
def unpack_spec_types(
spec: Union[Type]|Type,
) -> set[Type]:
'''
Given an input type-`spec`, either a lone type
or a `Union` of types (like `str|int|MyThing`),
return a set of individual types.
When `spec` is not a type-union returns `{spec,}`.
'''
spec_subtypes: set[Union[Type]] = set(
getattr(
spec,
'__args__',
{spec,},
)
)
return spec_subtypes
def mk_msgspec_table(
dec: msgpack.Decoder,
msg: MsgType|None = None,
) -> dict[str, MsgType]|str:
'''
Fill out a `dict` of `MsgType`s keyed by name
for a given input `msgspec.msgpack.Decoder`
as defined by its `.type: Union[Type]` setting.
If `msg` is provided, only deliver a `dict` with a single
entry for that type.
'''
msgspec: Union[Type]|Type = dec.type
if not (msgtypes := getattr(msgspec, '__args__', False)):
msgtypes = [msgspec]
msgt_table: dict[str, MsgType] = {
msgt: str(msgt.__name__)
for msgt in msgtypes
}
if msg:
msgt: MsgType = type(msg)
str_repr: str = msgt_table[msgt]
return {msgt: str_repr}
return msgt_table
def pformat_msgspec(
codec: MsgCodec|MsgDec,
msg: MsgType|None = None,
join_char: str = '\n',
) -> str:
'''
Pretty `str` format the `msgspec.msgpack.Decoder.type` attribute
for display in (console) log messages as a nice (maybe multiline)
presentation of all supported `Struct`s (subtypes) available for
typed decoding.
'''
dec: msgpack.Decoder = getattr(codec, 'dec', codec)
return join_char.join(
mk_msgspec_table(
dec=dec,
msg=msg,
).values()
)
# TODO: overall IPC msg-spec features (i.e. in this mod)!
#
# -[ ] API changes towards being interchange lib agnostic!
# -[ ] capnproto has pre-compiled schema for eg..
# * https://capnproto.org/language.html
# * http://capnproto.github.io/pycapnp/quickstart.html
# * https://github.com/capnproto/pycapnp/blob/master/examples/addressbook.capnp
#
# -[ ] struct aware messaging coders as per:
# -[x] https://github.com/goodboy/tractor/issues/36
# -[ ] https://github.com/goodboy/tractor/issues/196
# -[ ] https://github.com/goodboy/tractor/issues/365
#
class MsgCodec(Struct):
'''
A IPC msg interchange format lib's encoder + decoder pair.
Pretty much nothing more then delegation to underlying
`msgspec.<interchange-protocol>.Encoder/Decoder`s for now.
'''
_enc: msgpack.Encoder
_dec: msgpack.Decoder
_pld_spec: Type[Struct]|Raw|Any
# _ext_types_box: Struct|None = None
def __repr__(self) -> str:
speclines: str = textwrap.indent(
pformat_msgspec(codec=self),
prefix=' '*3,
)
body: str = textwrap.indent(
f'|_lib = {self.lib.__name__!r}\n'
f'|_enc_hook: {self.enc.enc_hook}\n'
f'|_dec_hook: {self.dec.dec_hook}\n'
f'|_pld_spec: {self.pld_spec_str}\n'
# f'|\n'
f'|__msg_spec__:\n'
f'{speclines}\n',
prefix=' '*2,
)
return (
f'<{type(self).__name__}(\n'
f'{body}'
')>'
)
@property
def pld_spec(self) -> Type[Struct]|Raw|Any:
return self._pld_spec
@property
def pld_spec_str(self) -> str:
# TODO: could also use match: instead?
spec: Union[Type]|Type = self.pld_spec
# `typing.Union` case
if getattr(spec, '__args__', False):
return str(spec)
# just a single type
else:
return spec.__name__
# struct type unions
# https://jcristharif.com/msgspec/structs.html#tagged-unions
@property
def msg_spec(self) -> Union[Type[Struct]]:
# NOTE: defined and applied inside `mk_codec()`
return self._dec.type
# TODO: some way to make `pretty_struct.Struct` use this
# wrapped field over the `.msg_spec` one?
@property
def msg_spec_str(self) -> str:
return pformat_msgspec(self.msg_spec)
lib: ModuleType = msgspec
# TODO: use `functools.cached_property` for these ?
# https://docs.python.org/3/library/functools.html#functools.cached_property
@property
def enc(self) -> msgpack.Encoder:
return self._enc
# TODO: reusing encode buffer for perf?
# https://jcristharif.com/msgspec/perf-tips.html#reusing-an-output-buffer
_buf: bytearray = bytearray()
def encode(
self,
py_obj: Any|PayloadMsg,
use_buf: bool = False,
# ^-XXX-^ uhh why am i getting this?
# |_BufferError: Existing exports of data: object cannot be re-sized
as_ext_type: bool = False,
hide_tb: bool = True,
) -> bytes:
'''
Encode input python objects to `msgpack` bytes for
transfer on a tranport protocol connection.
When `use_buf == True` use the output buffer optimization:
https://jcristharif.com/msgspec/perf-tips.html#reusing-an-output-buffer
'''
__tracebackhide__: bool = hide_tb
if use_buf:
self._enc.encode_into(py_obj, self._buf)
return self._buf
return self._enc.encode(py_obj)
# try:
# return self._enc.encode(py_obj)
# except TypeError as typerr:
# typerr.add_note(
# '|_src error from `msgspec`'
# # f'|_{self._enc.encode!r}'
# )
# raise typerr
# TODO! REMOVE once i'm confident we won't ever need it!
#
# box: Struct = self._ext_types_box
# if (
# as_ext_type
# or
# (
# # XXX NOTE, auto-detect if the input type
# box
# and
# (ext_types := unpack_spec_types(
# spec=box.__annotations__['boxed'])
# )
# )
# ):
# match py_obj:
# # case PayloadMsg(pld=pld) if (
# # type(pld) in ext_types
# # ):
# # py_obj.pld = box(boxed=py_obj)
# # breakpoint()
# case _ if (
# type(py_obj) in ext_types
# ):
# py_obj = box(boxed=py_obj)
@property
def dec(self) -> msgpack.Decoder:
return self._dec
def decode(
self,
msg: bytes,
) -> Any:
'''
Decode received `msgpack` bytes into a local python object
with special `msgspec.Struct` (or other type) handling
determined by the
'''
# https://jcristharif.com/msgspec/usage.html#typed-decoding
return self._dec.decode(msg)
# ?TODO? time to remove this finally?
#
# -[x] TODO: a sub-decoder system as well?
# => No! already re-architected to include a "payload-receiver"
# now found in `._ops`.
#
# -[x] do we still want to try and support the sub-decoder with
# `.Raw` technique in the case that the `Generic` approach gives
# future grief?
# => well YES but NO, since we went with the `PldRx` approach
# instead!
#
# IF however you want to see the code that was staged for this
# from wayyy back, see the pure removal commit.
def mk_codec(
ipc_pld_spec: Union[Type[Struct]]|Any|Raw = Raw,
# tagged-struct-types-union set for `Decoder`ing of payloads, as
# per https://jcristharif.com/msgspec/structs.html#tagged-unions.
# NOTE that the default `Raw` here **is very intentional** since
# the `PldRx._pld_dec: MsgDec` is responsible for per ipc-ctx-task
# decoding of msg-specs defined by the user as part of **their**
# `tractor` "app's" type-limited IPC msg-spec.
# TODO: offering a per-msg(-field) type-spec such that
# the fields can be dynamically NOT decoded and left as `Raw`
# values which are later loaded by a sub-decoder specified
# by `tag_field: str` value key?
# payload_msg_specs: dict[
# str, # tag_field value as sub-decoder key
# Union[Type[Struct]] # `MsgType.pld` type spec
# ]|None = None,
libname: str = 'msgspec',
# settings for encoding-to-send extension-types,
# https://jcristharif.com/msgspec/extending.html#mapping-to-from-native-types
# dec_hook: Callable|None = None,
enc_hook: Callable|None = None,
ext_types: list[Type]|None = None,
# optionally provided msg-decoder from which we pull its,
# |_.dec_hook()
# |_.type
ext_dec: MsgDec|None = None
#
# ?TODO? other params we might want to support
# Encoder:
# write_buffer_size=write_buffer_size,
#
# Decoder:
# ext_hook: ext_hook_sig
) -> MsgCodec:
'''
Convenience factory for creating codecs eventually meant
to be interchange lib agnostic (i.e. once we support more then just
`msgspec` ;).
'''
pld_spec = ipc_pld_spec
if enc_hook:
if not ext_types:
raise TypeError(
f'If extending the serializable types with a custom encode hook (`enc_hook()`), '
f'you must also provide the expected type set that the hook will handle '
f'via a `ext_types: Union[Type]|None = None` argument!\n'
f'\n'
f'enc_hook = {enc_hook!r}\n'
f'ext_types = {ext_types!r}\n'
)
dec_hook: Callable|None = None
if ext_dec:
dec: msgspec.Decoder = ext_dec.dec
dec_hook = dec.dec_hook
pld_spec |= dec.type
if ext_types:
pld_spec |= Union[*ext_types]
# (manually) generate a msg-spec (how appropes) for all relevant
# payload-boxing-struct-msg-types, parameterizing the
# `PayloadMsg.pld: PayloadT` for the decoder such that all msgs
# in our SC-RPC-protocol will automatically decode to
# a type-"limited" payload (`Struct`) object (set).
(
ipc_msg_spec,
msg_types,
) = mk_msg_spec(
payload_type_union=pld_spec,
)
msg_spec_types: set[Type] = unpack_spec_types(ipc_msg_spec)
assert (
len(ipc_msg_spec.__args__) == len(msg_types)
and
len(msg_spec_types) == len(msg_types)
)
dec = msgpack.Decoder(
type=ipc_msg_spec,
dec_hook=dec_hook,
)
enc = msgpack.Encoder(
enc_hook=enc_hook,
)
codec = MsgCodec(
_enc=enc,
_dec=dec,
_pld_spec=pld_spec,
)
# sanity on expected backend support
assert codec.lib.__name__ == libname
return codec
# instance of the default `msgspec.msgpack` codec settings, i.e.
# no custom structs, hooks or other special types.
#
# XXX NOTE XXX, this will break our `Context.start()` call!
#
# * by default we roundtrip the started pld-`value` and if you apply
# this codec (globally anyway with `apply_codec()`) then the
# `roundtripped` value will include a non-`.pld: Raw` which will
# then type-error on the consequent `._ops.validte_payload_msg()`..
#
_def_msgspec_codec: MsgCodec = mk_codec(
ipc_pld_spec=Any,
)
# The built-in IPC `Msg` spec.
# Our composing "shuttle" protocol which allows `tractor`-app code
# to use any `msgspec` supported type as the `PayloadMsg.pld` payload,
# https://jcristharif.com/msgspec/supported-types.html
#
_def_tractor_codec: MsgCodec = mk_codec(
ipc_pld_spec=Raw, # XXX should be default righ!?
)
# -[x] TODO, IDEALLY provides for per-`trio.Task` specificity of the
# IPC msging codec used by the transport layer when doing
# `Channel.send()/.recv()` of wire data.
# => impled as our `PldRx` which is `Context` scoped B)
# ContextVar-TODO: DIDN'T WORK, kept resetting in every new task to default!?
# _ctxvar_MsgCodec: ContextVar[MsgCodec] = ContextVar(
# TreeVar-TODO: DIDN'T WORK, kept resetting in every new embedded nursery
# even though it's supposed to inherit from a parent context ???
#
# _ctxvar_MsgCodec: TreeVar[MsgCodec] = TreeVar(
#
# ^-NOTE-^: for this to work see the mods by @mikenerone from `trio` gitter:
#
# 22:02:54 <mikenerone> even for regular contextvars, all you have to do is:
# `task: Task = trio.lowlevel.current_task()`
# `task.parent_nursery.parent_task.context.run(my_ctx_var.set, new_value)`
#
# From a comment in his prop code he couldn't share outright:
# 1. For every TreeVar set in the current task (which covers what
# we need from SynchronizerFacade), walk up the tree until the
# root or finding one where the TreeVar is already set, setting
# it in all of the contexts along the way.
# 2. For each of those, we also forcibly set the values that are
# pending for child nurseries that have not yet accessed the
# TreeVar.
# 3. We similarly set the pending values for the child nurseries
# of the *current* task.
#
_ctxvar_MsgCodec: ContextVar[MsgCodec] = ContextVar(
'msgspec_codec',
default=_def_tractor_codec,
)
@cm
def apply_codec(
codec: MsgCodec,
ctx: Context|None = None,
) -> MsgCodec:
'''
Dynamically apply a `MsgCodec` to the current task's runtime
context such that all (of a certain class of payload
containing i.e. `MsgType.pld: PayloadT`) IPC msgs are
processed with it for that task.
Uses a `contextvars.ContextVar` to ensure the scope of any
codec setting matches the current `Context` or
`._rpc.process_messages()` feeder task's prior setting without
mutating any surrounding scope.
When a `ctx` is supplied, only mod its `Context.pld_codec`.
matches the `@cm` block and DOES NOT change to the original
(default) value in new tasks (as it does for `ContextVar`).
'''
__tracebackhide__: bool = True
if ctx is not None:
var: ContextVar = ctx._var_pld_codec
else:
# use IPC channel-connection "global" codec
var: ContextVar = _ctxvar_MsgCodec
orig: MsgCodec = var.get()
assert orig is not codec
if codec.pld_spec is None:
breakpoint()
log.info(
'Applying new msg-spec codec\n\n'
f'{codec}\n'
)
token: Token = var.set(codec)
try:
yield var.get()
finally:
var.reset(token)
log.info(
'Reverted to last msg-spec codec\n\n'
f'{orig}\n'
)
assert var.get() is orig
# ?TODO? for TreeVar approach which copies from the
# cancel-scope of the prior value, NOT the prior task
#
# See the docs:
# - https://tricycle.readthedocs.io/en/latest/reference.html#tree-variables
# - https://github.com/oremanj/tricycle/blob/master/tricycle/_tests/test_tree_var.py
# ^- see docs for @cm `.being()` API
#
# with _ctxvar_MsgCodec.being(codec):
# new = _ctxvar_MsgCodec.get()
# assert new is codec
# yield codec
def current_codec() -> MsgCodec:
'''
Return the current `trio.Task.context`'s value
for `msgspec_codec` used by `Channel.send/.recv()`
for wire serialization.
'''
return _ctxvar_MsgCodec.get()
@cm
def limit_msg_spec(
payload_spec: Union[Type[Struct]],
# TODO: don't need this approach right?
# -> related to the `MsgCodec._payload_decs` stuff above..
# tagged_structs: list[Struct]|None = None,
hide_tb: bool = True,
**codec_kwargs,
) -> MsgCodec:
'''
Apply a `MsgCodec` that will natively decode the SC-msg set's
`PayloadMsg.pld: Union[Type[Struct]]` payload fields using
tagged-unions of `msgspec.Struct`s from the `payload_types`
for all IPC contexts in use by the current `trio.Task`.
'''
__tracebackhide__: bool = hide_tb
curr_codec: MsgCodec = current_codec()
msgspec_codec: MsgCodec = mk_codec(
ipc_pld_spec=payload_spec,
**codec_kwargs,
)
with apply_codec(msgspec_codec) as applied_codec:
assert applied_codec is msgspec_codec
yield msgspec_codec
assert curr_codec is current_codec()
# XXX: msgspec won't allow this with non-struct custom types
# like `NamespacePath`!@!
# @cm
# def extend_msg_spec(
# payload_spec: Union[Type[Struct]],
# ) -> MsgCodec:
# '''
# Extend the current `MsgCodec.pld_spec` (type set) by extending
# the payload spec to **include** the types specified by
# `payload_spec`.
# '''
# codec: MsgCodec = current_codec()
# pld_spec: Union[Type] = codec.pld_spec
# extended_spec: Union[Type] = pld_spec|payload_spec
# with limit_msg_spec(payload_types=extended_spec) as ext_codec:
# # import pdbp; pdbp.set_trace()
# assert ext_codec.pld_spec == extended_spec
# yield ext_codec
#
# ^-TODO-^ is it impossible to make something like this orr!?
# TODO: make an auto-custom hook generator from a set of input custom
# types?
# -[ ] below is a proto design using a `TypeCodec` idea?
#
# type var for the expected interchange-lib's
# IPC-transport type when not available as a built-in
# serialization output.
WireT = TypeVar('WireT')
# TODO: some kinda (decorator) API for built-in subtypes
# that builds this implicitly by inspecting the `mro()`?
class TypeCodec(Protocol):
'''
A per-custom-type wire-transport serialization translator
description type.
'''
src_type: Type
wire_type: WireT
def encode(obj: Type) -> WireT:
...
def decode(
obj_type: Type[WireT],
obj: WireT,
) -> Type:
...
class MsgpackTypeCodec(TypeCodec):
...
def mk_codec_hooks(
type_codecs: list[TypeCodec],
) -> tuple[Callable, Callable]:
'''
Deliver a `enc_hook()`/`dec_hook()` pair which handle
manual convertion from an input `Type` set such that whenever
the `TypeCodec.filter()` predicate matches the
`TypeCodec.decode()` is called on the input native object by
the `dec_hook()` and whenever the
`isiinstance(obj, TypeCodec.type)` matches against an
`enc_hook(obj=obj)` the return value is taken from a
`TypeCodec.encode(obj)` callback.
'''
...
View Git Blame Copy Permalink