forked from goodboy/tractor
1
0
Fork 0
tractor/tractor/msg/ptr.py

140 lines
4.4 KiB
Python

# 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-compat cross-mem-boundary object pointer.
'''
# TODO: integration with our ``enable_modules: list[str]`` caps sys.
# ``pkgutil.resolve_name()`` internally uses
# ``importlib.import_module()`` which can be filtered by inserting
# a ``MetaPathFinder`` into ``sys.meta_path`` (which we could do before
# entering the ``_runtime.process_messages()`` loop).
# - https://github.com/python/cpython/blob/main/Lib/pkgutil.py#L645
# - https://stackoverflow.com/questions/1350466/preventing-python-code-from-importing-certain-modules
# - https://stackoverflow.com/a/63320902
# - https://docs.python.org/3/library/sys.html#sys.meta_path
# the new "Implicit Namespace Packages" might be relevant?
# - https://www.python.org/dev/peps/pep-0420/
# add implicit serialized message type support so that paths can be
# handed directly to IPC primitives such as streams and `Portal.run()`
# calls:
# - via ``msgspec``:
# - https://jcristharif.com/msgspec/api.html#struct
# - https://jcristharif.com/msgspec/extending.html
# via ``msgpack-python``:
# - https://github.com/msgpack/msgpack-python#packingunpacking-of-custom-data-type
from __future__ import annotations
from inspect import (
isfunction,
ismethod,
)
from pkgutil import resolve_name
class NamespacePath(str):
'''
A serializeable `str`-subtype implementing a "namespace
pointer" to any Python object reference (like a function)
using the same format as the built-in `pkgutil.resolve_name()`
system.
A value describes a target's module-path and namespace-key
separated by a ':' and thus can be easily used as
a IPC-message-native reference-type allowing memory isolated
actors to point-and-load objects via a minimal `str` value.
'''
_ref: object | type | None = None
# TODO: support providing the ns instance in
# order to support 'self.<meth>` style to make
# `Portal.run_from_ns()` work!
# _ns: ModuleType|type|None = None
def load_ref(self) -> object | type:
if self._ref is None:
self._ref = resolve_name(self)
return self._ref
@staticmethod
def _mk_fqnp(
ref: type|object,
) -> tuple[str, str]:
'''
Generate a minial `str` pair which describes a python
object's namespace path and object/type name.
In more precise terms something like:
- 'py.namespace.path:object_name',
- eg.'tractor.msg:NamespacePath' will be the ``str`` form
of THIS type XD
'''
if isfunction(ref):
name: str = getattr(ref, '__name__')
mod_name: str = ref.__module__
elif ismethod(ref):
# build out the path manually i guess..?
# TODO: better way?
name: str = '.'.join([
type(ref.__self__).__name__,
ref.__func__.__name__,
])
mod_name: str = ref.__self__.__module__
else: # object or other?
# isinstance(ref, object)
# and not isfunction(ref)
name: str = type(ref).__name__
mod_name: str = ref.__module__
# TODO: return static value direactly?
#
# fully qualified namespace path, tuple.
fqnp: tuple[str, str] = (
mod_name,
name,
)
return fqnp
@classmethod
def from_ref(
cls,
ref: type|object,
) -> NamespacePath:
fqnp: tuple[str, str] = cls._mk_fqnp(ref)
return cls(':'.join(fqnp))
def to_tuple(
self,
# TODO: could this work re `self:<meth>` case from above?
# load_ref: bool = True,
) -> tuple[str, str]:
return self._mk_fqnp(
self.load_ref()
)