forked from goodboy/tractor
116 lines
2.8 KiB
Python
116 lines
2.8 KiB
Python
"""
|
|
Our classy exception set.
|
|
"""
|
|
from typing import Dict, Any, Optional, Type
|
|
import importlib
|
|
import builtins
|
|
import traceback
|
|
|
|
import trio
|
|
|
|
|
|
_this_mod = importlib.import_module(__name__)
|
|
|
|
|
|
class RemoteActorError(Exception):
|
|
# TODO: local recontruction of remote exception deats
|
|
"Remote actor exception bundled locally"
|
|
def __init__(
|
|
self,
|
|
message: str,
|
|
suberror_type: Optional[Type[BaseException]] = None,
|
|
**msgdata
|
|
|
|
) -> None:
|
|
super().__init__(message)
|
|
|
|
self.type = suberror_type
|
|
self.msgdata = msgdata
|
|
|
|
# TODO: a trio.MultiError.catch like context manager
|
|
# for catching underlying remote errors of a particular type
|
|
|
|
|
|
class InternalActorError(RemoteActorError):
|
|
"""Remote internal ``tractor`` error indicating
|
|
failure of some primitive or machinery.
|
|
"""
|
|
|
|
|
|
class ContextCancelled(RemoteActorError):
|
|
"Inter-actor task context cancelled itself on the callee side."
|
|
|
|
|
|
class NoResult(RuntimeError):
|
|
"No final result is expected for this actor"
|
|
|
|
|
|
class ModuleNotExposed(ModuleNotFoundError):
|
|
"The requested module is not exposed for RPC"
|
|
|
|
|
|
class NoRuntime(RuntimeError):
|
|
"The root actor has not been initialized yet"
|
|
|
|
|
|
def pack_error(exc: BaseException) -> Dict[str, Any]:
|
|
"""Create an "error message" for tranmission over
|
|
a channel (aka the wire).
|
|
"""
|
|
return {
|
|
'error': {
|
|
'tb_str': traceback.format_exc(),
|
|
'type_str': type(exc).__name__,
|
|
}
|
|
}
|
|
|
|
|
|
def unpack_error(
|
|
msg: Dict[str, Any],
|
|
chan=None,
|
|
err_type=RemoteActorError
|
|
) -> Exception:
|
|
"""Unpack an 'error' message from the wire
|
|
into a local ``RemoteActorError``.
|
|
"""
|
|
error = msg['error']
|
|
|
|
tb_str = error.get('tb_str', '')
|
|
message = f"{chan.uid}\n" + tb_str
|
|
type_name = error['type_str']
|
|
suberror_type: Type[BaseException] = Exception
|
|
|
|
if type_name == 'ContextCancelled':
|
|
err_type = ContextCancelled
|
|
suberror_type = trio.Cancelled
|
|
|
|
else: # try to lookup a suitable local error type
|
|
for ns in [builtins, _this_mod, trio]:
|
|
try:
|
|
suberror_type = getattr(ns, type_name)
|
|
break
|
|
except AttributeError:
|
|
continue
|
|
|
|
exc = err_type(
|
|
message,
|
|
suberror_type=suberror_type,
|
|
|
|
# unpack other fields into error type init
|
|
**msg['error'],
|
|
)
|
|
|
|
return exc
|
|
|
|
|
|
def is_multi_cancelled(exc: BaseException) -> bool:
|
|
"""Predicate to determine if a ``trio.MultiError`` contains only
|
|
``trio.Cancelled`` sub-exceptions (and is likely the result of
|
|
cancelling a collection of subtasks.
|
|
|
|
"""
|
|
return not trio.MultiError.filter(
|
|
lambda exc: exc if not isinstance(exc, trio.Cancelled) else None,
|
|
exc,
|
|
)
|