forked from goodboy/tractor
265 lines
8.4 KiB
Python
265 lines
8.4 KiB
Python
"""
|
|
Portal api
|
|
"""
|
|
import importlib
|
|
import inspect
|
|
import typing
|
|
from typing import Tuple, Any, Dict, Optional
|
|
|
|
import trio
|
|
from async_generator import asynccontextmanager
|
|
|
|
from ._state import current_actor
|
|
from ._ipc import Channel
|
|
from .log import get_logger
|
|
|
|
|
|
log = get_logger('tractor')
|
|
|
|
|
|
class RemoteActorError(RuntimeError):
|
|
"Remote actor exception bundled locally"
|
|
|
|
|
|
@asynccontextmanager
|
|
async def maybe_open_nursery(nursery: trio._core._run.Nursery = None):
|
|
"""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 trio.open_nursery() as nursery:
|
|
yield nursery
|
|
|
|
|
|
async def _do_handshake(
|
|
actor: 'Actor', # type: ignore
|
|
chan: Channel
|
|
)-> Any:
|
|
await chan.send(actor.uid)
|
|
uid: Tuple[str, str] = await chan.recv()
|
|
|
|
if not isinstance(uid, tuple):
|
|
raise ValueError(f"{uid} is not a valid uid?!")
|
|
|
|
chan.uid = uid
|
|
log.info(f"Handshake with actor {uid}@{chan.raddr} complete")
|
|
return uid
|
|
|
|
|
|
class Portal:
|
|
"""A 'portal' to a(n) (remote) ``Actor``.
|
|
|
|
Allows for invoking remote routines and receiving results through an
|
|
underlying ``tractor.Channel`` as though the remote (async)
|
|
function / generator was invoked locally.
|
|
|
|
Think of this like an native async IPC API.
|
|
"""
|
|
def __init__(self, channel: Channel) -> None:
|
|
self.channel = channel
|
|
# when this is set to a tuple returned from ``_submit()`` then
|
|
# it is expected that ``result()`` will be awaited at some point
|
|
# during the portal's lifetime
|
|
self._result = None
|
|
self._exc: Optional[RemoteActorError] = None
|
|
self._expect_result: Optional[
|
|
Tuple[str, Any, str, Dict[str, Any]]
|
|
] = None
|
|
|
|
async def aclose(self) -> None:
|
|
log.debug(f"Closing {self}")
|
|
# XXX: won't work until https://github.com/python-trio/trio/pull/460
|
|
# gets in!
|
|
await self.channel.aclose()
|
|
|
|
async def _submit(
|
|
self, ns: str, func: str, **kwargs
|
|
) -> Tuple[str, trio.Queue, str, Dict[str, Any]]:
|
|
"""Submit a function to be scheduled and run by actor, return the
|
|
associated caller id, response queue, response type str,
|
|
first message packet as a tuple.
|
|
|
|
This is an async call.
|
|
"""
|
|
# ship a function call request to the remote actor
|
|
cid, q = await current_actor().send_cmd(self.channel, ns, func, kwargs)
|
|
|
|
# wait on first response msg and handle (this should be
|
|
# in an immediate response)
|
|
first_msg = await q.get()
|
|
functype = first_msg.get('functype')
|
|
|
|
if functype == 'function' or functype == 'asyncfunction':
|
|
resp_type = 'return'
|
|
elif functype == 'asyncgen':
|
|
resp_type = 'yield'
|
|
elif 'error' in first_msg:
|
|
raise RemoteActorError(
|
|
f"{self.channel.uid}\n" + first_msg['error'])
|
|
else:
|
|
raise ValueError(f"{first_msg} is an invalid response packet?")
|
|
|
|
return cid, q, resp_type, first_msg
|
|
|
|
async def _submit_for_result(self, ns: str, func: str, **kwargs) -> None:
|
|
assert self._expect_result is None, \
|
|
"A pending main result has already been submitted"
|
|
self._expect_result = await self._submit(ns, func, **kwargs)
|
|
|
|
async def run(self, ns: str, func: str, **kwargs) -> Any:
|
|
"""Submit a function to be scheduled and run by actor, wrap and return
|
|
its (stream of) result(s).
|
|
|
|
This is a blocking call.
|
|
"""
|
|
return await self._return_from_resptype(
|
|
*(await self._submit(ns, func, **kwargs))
|
|
)
|
|
|
|
async def _return_from_resptype(
|
|
self, cid: str, q: trio.Queue, resptype: str, first_msg: dict
|
|
) -> Any:
|
|
# TODO: not this needs some serious work and thinking about how
|
|
# to make async-generators the fundamental IPC API over channels!
|
|
# (think `yield from`, `gen.send()`, and functional reactive stuff)
|
|
|
|
if resptype == 'yield':
|
|
|
|
async def yield_from_q():
|
|
try:
|
|
async for msg in q:
|
|
try:
|
|
yield msg['yield']
|
|
except KeyError:
|
|
if 'stop' in msg:
|
|
break # far end async gen terminated
|
|
else:
|
|
raise RemoteActorError(
|
|
f"{self.channel.uid}\n" + msg['error'])
|
|
except StopAsyncIteration:
|
|
log.debug(
|
|
f"Cancelling async gen call {cid} to "
|
|
f"{self.channel.uid}")
|
|
raise
|
|
|
|
return yield_from_q()
|
|
|
|
elif resptype == 'return':
|
|
msg = await q.get()
|
|
try:
|
|
return msg['return']
|
|
except KeyError:
|
|
self._exc = RemoteActorError(
|
|
f"{self.channel.uid}\n" + msg['error'])
|
|
raise self._exc
|
|
else:
|
|
raise ValueError(f"Unknown msg response type: {first_msg}")
|
|
|
|
async def result(self) -> Any:
|
|
"""Return the result(s) from the remote actor's "main" task.
|
|
"""
|
|
if self._expect_result is None:
|
|
# (remote) errors are slapped on the channel
|
|
# teardown can reraise them
|
|
exc = self.channel._exc
|
|
if exc:
|
|
raise RemoteActorError(f"{self.channel.uid}\n{exc}")
|
|
else:
|
|
raise RuntimeError(
|
|
f"Portal for {self.channel.uid} is not expecting a final"
|
|
"result?")
|
|
|
|
elif self._result is None:
|
|
self._result = await self._return_from_resptype(
|
|
*self._expect_result
|
|
)
|
|
return self._result
|
|
|
|
async def close(self) -> None:
|
|
# trigger remote msg loop `break`
|
|
chan = self.channel
|
|
log.debug(f"Closing portal for {chan} to {chan.uid}")
|
|
await self.channel.send(None)
|
|
|
|
async def cancel_actor(self) -> bool:
|
|
"""Cancel the actor on the other end of this portal.
|
|
"""
|
|
log.warning(
|
|
f"Sending cancel request to {self.channel.uid} on "
|
|
f"{self.channel}")
|
|
try:
|
|
with trio.move_on_after(0.1) as cancel_scope:
|
|
cancel_scope.shield = True
|
|
# send cancel cmd - might not get response
|
|
await self.run('self', 'cancel')
|
|
return True
|
|
except trio.ClosedResourceError:
|
|
log.warning(
|
|
f"{self.channel} for {self.channel.uid} was already closed?")
|
|
return False
|
|
else:
|
|
log.warning(f"May have failed to cancel {self.channel.uid}")
|
|
return False
|
|
|
|
|
|
class LocalPortal:
|
|
"""A 'portal' to a local ``Actor``.
|
|
|
|
A compatibility shim for normal portals but for invoking functions
|
|
using an in process actor instance.
|
|
"""
|
|
def __init__(
|
|
self,
|
|
actor: 'Actor' # type: ignore
|
|
) -> None:
|
|
self.actor = actor
|
|
|
|
async def run(self, ns: str, func_name: str, **kwargs) -> Any:
|
|
"""Run a requested function locally and return it's result.
|
|
"""
|
|
obj = self.actor if ns == 'self' else importlib.import_module(ns)
|
|
func = getattr(obj, func_name)
|
|
if inspect.iscoroutinefunction(func):
|
|
return await func(**kwargs)
|
|
else:
|
|
return func(**kwargs)
|
|
|
|
|
|
@asynccontextmanager
|
|
async def open_portal(
|
|
channel: Channel,
|
|
nursery: trio._core._run.Nursery = None
|
|
) -> typing.AsyncGenerator[Portal, None]:
|
|
"""Open a ``Portal`` through the provided ``channel``.
|
|
|
|
Spawns a background task to handle message processing.
|
|
"""
|
|
actor = current_actor()
|
|
assert actor
|
|
was_connected = False
|
|
|
|
async with maybe_open_nursery(nursery) as nursery:
|
|
|
|
if not channel.connected():
|
|
await channel.connect()
|
|
was_connected = True
|
|
|
|
if channel.uid is None:
|
|
await _do_handshake(actor, channel)
|
|
|
|
nursery.start_soon(actor._process_messages, channel)
|
|
portal = Portal(channel)
|
|
yield portal
|
|
|
|
# cancel remote channel-msg loop
|
|
if channel.connected():
|
|
await portal.close()
|
|
|
|
# cancel background msg loop task
|
|
nursery.cancel_scope.cancel()
|
|
if was_connected:
|
|
await channel.aclose()
|