tractor/tractor/trionics/_tn.py

95 lines
2.4 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/>.
'''
`trio.Nursery` wrappers which we short-hand refer to as
`tn`: "task nursery".
(whereas we refer to `tractor.ActorNursery` as the short-hand `an`)
'''
from __future__ import annotations
from contextlib import (
asynccontextmanager as acm,
)
from types import ModuleType
from typing import (
Any,
AsyncGenerator,
TYPE_CHECKING,
)
import trio
from tractor.log import get_logger
# from ._beg import (
# collapse_eg,
# )
if TYPE_CHECKING:
from tractor import ActorNursery
log = get_logger(__name__)
# ??TODO? is this even a good idea??
# it's an extra LoC to stack `collapse_eg()` vs.
# a new/foreign/bad-std-named very thing wrapper..?
# -[ ] is there a better/simpler name?
# @acm
# async def open_loose_tn() -> trio.Nursery:
# '''
# Implements the equivalent of the old style loose eg raising
# task-nursery from `trio<=0.25.0` ,
# .. code-block:: python
# async with trio.open_nursery(
# strict_exception_groups=False,
# ) as tn:
# ...
# '''
# async with (
# collapse_eg(),
# trio.open_nursery() as tn,
# ):
# yield tn
@acm
async def maybe_open_nursery(
nursery: trio.Nursery|ActorNursery|None = None,
shield: bool = False,
lib: ModuleType = trio,
loose: bool = False,
**kwargs, # proxy thru
) -> AsyncGenerator[trio.Nursery, Any]:
'''
Create a new nursery if None provided.
Blocks on exit as expected if no input nursery is provided.
'''
if nursery is not None:
yield nursery
else:
async with lib.open_nursery(**kwargs) as tn:
tn.cancel_scope.shield = shield
yield tn