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Unify `MsgTypeError` as a `RemoteActorError` subtype 

Since in the receive-side error case the source of the exception is the
sender side (normally causing a local `TypeError` at decode time), might
as well bundle the error in remote-capture-style using boxing semantics
around the causing local type error raised from the
`msgspec.msgpack.Decoder.decode()` and with a traceback packed from
`msgspec`-specific knowledge of any field-type spec matching failure.

Deats on new `MsgTypeError` interface:
- includes a `.msg_dict` to get access to any `Decoder.type`-applied
  load of the original (underlying and offending) IPC msg into
  a `dict` form using a vanilla decoder which is normally packed into
  the instance as a `._msg_dict`.
- a public getter to the "supposed offending msg" via `.payload_msg`
  which attempts to take the above `.msg_dict` and load it manually into
  the corresponding `.msg.types.MsgType` struct.
- a constructor `.from_decode()` to make it simple to build out error
  instances from a failed decode scope where the aforementioned
  `msgdict: dict` from the vanilla decode can be provided directly.
- ALSO, we now pack into `MsgTypeError` directly just like ctxc in
  `unpack_error()`

This also completes the while-standing todo for `RemoteActorError` to
contain a ref to the underlying `Error` msg as `._ipc_msg` with public
`@property` access that `defstruct()`-creates a pretty struct version
via `.ipc_msg`.

Internal tweaks for this include:
- `._ipc_msg` is the internal literal `Error`-msg instance if provided
  with `.ipc_msg` the dynamic wrapper as mentioned above.
- `.__init__()` now can still take variable `**extra_msgdata` (similar
  to the `dict`-msgdata as before) to maintain support for subtypes
  which are constructed manually (not only by `pack_error()`) and insert
  their own attrs which get placed in a `._extra_msgdata: dict` if no
  `ipc_msg: Error` is provided as input.
- the `.msgdata` is now a merge of any `._extra_msgdata` and
  a `dict`-casted form of any `._ipc_msg`.
- adjust all previous `.msgdata` field lookups to try equivalent field
  reads on `._ipc_msg: Error`.
- drop default single ws indent from `.tb_str` and do a failover lookup
  to `.msgdata` when `._ipc_msg is None` for the manually constructed
  subtype-instance case.
- add a new class attr `.extra_body_fields: list[str]` to allow subtypes
  to declare attrs they want shown in the `.__repr__()` output, eg.
  `ContextCancelled.canceller`, `StreamOverrun.sender` and
  `MsgTypeError.payload_msg`.
- ^-rework defaults pertaining to-^ with rename from
  `_msgdata_keys` -> `_ipcmsg_keys` with latter now just loading directly
  from the `Error` fields def and `_body_fields: list[str]` just taking
  that value and removing the not-so-useful-in-REPL or already shown
  (i.e. `.tb_str: str`) field names.
- add a new mod level `.pack_from_raise()` helper for auto-boxing RAE
  subtypes constructed manually into `Error`s which is normally how
  `StreamOverrun` and `MsgTypeError` get created in the runtime.
- in support of the above expose a `src_uid: tuple` override to
  `pack_error()` such that the runtime can provide any remote actor id
  when packing a locally-created yet remotely-caused RAE subtype.
- adjust all typing to expect `Error`s over `dict`-msgs.

Adjust some tests to match these changes:
- context and inter-peer-cancel tests to make their `.msgdata` related
  checks against the new `.ipc_msg` as well and `.tb_str` directly.
- toss in an extra sleep to `sleep_a_bit_then_cancel_peer()` to keep the
  'canceller' ctx child task cancelled by it's parent in the 'root' for
  the rte-raised-during-ctxc-handling case (apparently now it's
  returning too fast, cool?).
runtime_to_msgspec
Tyler Goodlet 2024-04-09 08:44:06 -04:00
parent b341146bd1
commit cf48fdecfe
3 changed files with 333 additions and 102 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
tests/test_context_stream_semantics.py
View File

@ -796,10 +796,12 @@ async def test_callee_cancels_before_started(
# raises a special cancel signal
except tractor.ContextCancelled as ce:
_ce = ce # for debug on crash
ce.boxed_type == trio.Cancelled
# the traceback should be informative
assert 'itself' in ce.msgdata['tb_str']
assert 'itself' in ce.tb_str
assert ce.tb_str == ce.msgdata['tb_str']
# teardown the actor
await portal.cancel_actor()
@ -1157,7 +1159,8 @@ def test_maybe_allow_overruns_stream(
elif slow_side == 'parent':
assert err.boxed_type == tractor.RemoteActorError
assert 'StreamOverrun' in err.msgdata['tb_str']
assert 'StreamOverrun' in err.tb_str
assert err.tb_str == err.msgdata['tb_str']
else:
# if this hits the logic blocks from above are not

10
tests/test_inter_peer_cancellation.py
View File

@ -185,6 +185,10 @@ async def sleep_a_bit_then_cancel_peer(
await trio.sleep(cancel_after)
await peer.cancel_actor()
# such that we're cancelled by our rent ctx-task
await trio.sleep(3)
print('CANCELLER RETURNING!')
@tractor.context
async def stream_ints(
@ -245,6 +249,12 @@ async def stream_from_peer(
assert peer_ctx._remote_error is ctxerr
assert peer_ctx._remote_error.msgdata == ctxerr.msgdata
# XXX YES, bc exact same msg instances
assert peer_ctx._remote_error._ipc_msg is ctxerr._ipc_msg
# XXX NO, bc new one always created for property accesss
assert peer_ctx._remote_error.ipc_msg != ctxerr.ipc_msg
# the peer ctx is the canceller even though it's canceller
# is the "canceller" XD
assert peer_name in peer_ctx.canceller

418
tractor/_exceptions.py
View File

@ -31,7 +31,10 @@ import textwrap
import traceback
import trio
from msgspec import structs
from msgspec import (
structs,
defstruct,
)
from tractor._state import current_actor
from tractor.log import get_logger
@ -40,6 +43,8 @@ from tractor.msg import (
Msg,
Stop,
Yield,
pretty_struct,
types as msgtypes,
)
if TYPE_CHECKING:
@ -64,21 +69,38 @@ class InternalError(RuntimeError):
'''
_body_fields: list[str] = [
'boxed_type',
'src_type',
# TODO: format this better if we're going to include it.
# 'relay_path',
'src_uid',
# only in sub-types
'canceller',
'sender',
# NOTE: more or less should be close to these:
# 'boxed_type',
# 'src_type',
# 'src_uid',
# 'canceller',
# 'sender',
# TODO: format this better if we're going to include it.
# 'relay_path',
#
_ipcmsg_keys: list[str] = [
fi.name
for fi, k, v
in pretty_struct.iter_fields(Error)
]
_msgdata_keys: list[str] = [
'boxed_type_str',
] + _body_fields
_body_fields: list[str] = list(
set(_ipcmsg_keys)
# NOTE: don't show fields that either don't provide
# any extra useful info or that are already shown
# as part of `.__repr__()` output.
- {
'src_type_str',
'boxed_type_str',
'tb_str',
'relay_path',
'_msg_dict',
'cid',
}
)
def get_err_type(type_name: str) -> BaseException|None:
@ -137,7 +159,7 @@ def pformat_boxed_tb(
f'|\n'
f' ------ - ------\n\n'
f'{tb_str}\n'
f' ------ - ------\n'
f' ------ - ------\n'
f'_|\n'
)
if len(indent):
@ -152,10 +174,40 @@ def pformat_boxed_tb(
+
body
)
# return body
# TODO: rename to just `RemoteError`?
def pack_from_raise(
local_err: (
ContextCancelled
|StreamOverrun
|MsgTypeError
),
cid: str,
**rae_fields,
) -> Error:
'''
Raise the provided `RemoteActorError` subtype exception
instance locally to get a traceback and pack it into an IPC
`Error`-msg using `pack_error()` to extract the tb info.
'''
try:
raise local_err
except type(local_err) as local_err:
err_msg: dict[str, dict] = pack_error(
local_err,
cid=cid,
**rae_fields,
)
return err_msg
# TODO: better compat with IPC msg structs?
# -[ ] rename to just `RemoteError` like in `mp.manager`?
# -[ ] make a `Struct`-subtype by using the .__post_init__()`?
# https://jcristharif.com/msgspec/structs.html#post-init-processing
class RemoteActorError(Exception):
'''
A box(ing) type which bundles a remote actor `BaseException` for
@ -170,12 +222,28 @@ class RemoteActorError(Exception):
'src_uid',
# 'relay_path',
]
extra_body_fields: list[str] = [
'cid',
'boxed_type',
]
def __init__(
self,
message: str,
ipc_msg: Error|None = None,
boxed_type: Type[BaseException]|None = None,
**msgdata
# NOTE: only provided by subtypes (ctxc and overruns)
# wishing to both manually instantiate and add field
# values defined on `Error` without having to construct an
# `Error()` before the exception is processed by
# `pack_error()`.
#
# TODO: a better way to support this without the extra
# private `._extra_msgdata`?
# -[ ] ctxc constructed inside `._rpc._invoke()` L:638
# -[ ] overrun @ `._context.Context._deliver_msg()` L:1958
**extra_msgdata,
) -> None:
super().__init__(message)
@ -188,14 +256,24 @@ class RemoteActorError(Exception):
# - .remote_type
# also pertains to our long long oustanding issue XD
# https://github.com/goodboy/tractor/issues/5
#
# TODO: always set ._boxed_type` as `None` by default
# and instead render if from `.boxed_type_str`?
self._boxed_type: BaseException = boxed_type
self._src_type: BaseException|None = None
self._ipc_msg: Error|None = ipc_msg
# TODO: make this a `.errmsg: Error` throughout?
self.msgdata: dict[str, Any] = msgdata
if (
extra_msgdata
and ipc_msg
):
# XXX mutate the orig msg directly from
# manually provided input params.
for k, v in extra_msgdata.items():
setattr(
self._ipc_msg,
k,
v,
)
else:
self._extra_msgdata = extra_msgdata
# TODO: mask out eventually or place in `pack_error()`
# pre-`return` lines?
@ -214,14 +292,56 @@ class RemoteActorError(Exception):
# either by customizing `ContextCancelled.__init__()` or
# through a special factor func?
elif boxed_type:
if not self.msgdata.get('boxed_type_str'):
self.msgdata['boxed_type_str'] = str(
type(boxed_type).__name__
)
boxed_type_str: str = type(boxed_type).__name__
if (
ipc_msg
and not self._ipc_msg.boxed_type_str
):
self._ipc_msg.boxed_type_str = boxed_type_str
assert self.boxed_type_str == self._ipc_msg.boxed_type_str
else:
self._extra_msgdata['boxed_type_str'] = boxed_type_str
assert self.boxed_type_str == self.msgdata['boxed_type_str']
assert self.boxed_type is boxed_type
@property
def ipc_msg(self) -> pretty_struct.Struct:
'''
Re-render the underlying `._ipc_msg: Msg` as
a `pretty_struct.Struct` for introspection such that the
returned value is a read-only copy of the original.
'''
if self._ipc_msg is None:
return None
msg_type: Msg = type(self._ipc_msg)
fields: dict[str, Any] = {
k: v for _, k, v in
pretty_struct.iter_fields(self._ipc_msg)
}
return defstruct(
msg_type.__name__,
fields=fields.keys(),
bases=(msg_type, pretty_struct.Struct),
)(**fields)
@property
def msgdata(self) -> dict[str, Any]:
'''
The (remote) error data provided by a merge of the
`._ipc_msg: Error` msg and any input `._extra_msgdata: dict`
(provided by subtypes via `.__init__()`).
'''
msgdata: dict = (
structs.asdict(self._ipc_msg)
if self._ipc_msg
else {}
)
return self._extra_msgdata | msgdata
@property
def src_type_str(self) -> str:
'''
@ -231,7 +351,7 @@ class RemoteActorError(Exception):
at the first relay/hop's receiving actor.
'''
return self.msgdata['src_type_str']
return self._ipc_msg.src_type_str
@property
def src_type(self) -> str:
@ -241,7 +361,7 @@ class RemoteActorError(Exception):
'''
if self._src_type is None:
self._src_type = get_err_type(
self.msgdata['src_type_str']
self._ipc_msg.src_type_str
)
return self._src_type
@ -252,7 +372,7 @@ class RemoteActorError(Exception):
String-name of the (last hop's) boxed error type.
'''
return self.msgdata['boxed_type_str']
return self._ipc_msg.boxed_type_str
@property
def boxed_type(self) -> str:
@ -262,7 +382,7 @@ class RemoteActorError(Exception):
'''
if self._boxed_type is None:
self._boxed_type = get_err_type(
self.msgdata['boxed_type_str']
self._ipc_msg.boxed_type_str
)
return self._boxed_type
@ -275,40 +395,44 @@ class RemoteActorError(Exception):
actor's hop.
NOTE: a `list` field with the same name is expected to be
passed/updated in `.msgdata`.
passed/updated in `.ipc_msg`.
'''
return self.msgdata['relay_path']
return self._ipc_msg.relay_path
@property
def relay_uid(self) -> tuple[str, str]|None:
return tuple(
self.msgdata['relay_path'][-1]
self._ipc_msg.relay_path[-1]
)
@property
def src_uid(self) -> tuple[str, str]|None:
if src_uid := (
self.msgdata.get('src_uid')
self._ipc_msg.src_uid
):
return tuple(src_uid)
# TODO: use path lookup instead?
# return tuple(
# self.msgdata['relay_path'][0]
# self._ipc_msg.relay_path[0]
# )
@property
def tb_str(
self,
indent: str = ' ',
indent: str = '',
) -> str:
if remote_tb := self.msgdata.get('tb_str'):
return textwrap.indent(
remote_tb,
prefix=indent,
)
remote_tb: str = ''
return ''
if self._ipc_msg:
remote_tb: str = self._ipc_msg.tb_str
else:
remote_tb = self.msgdata.get('tb_str')
return textwrap.indent(
remote_tb or '',
prefix=indent,
)
def _mk_fields_str(
self,
@ -320,14 +444,17 @@ class RemoteActorError(Exception):
val: Any|None = (
getattr(self, key, None)
or
self.msgdata.get(key)
getattr(
self._ipc_msg,
key,
None,
)
)
# TODO: for `.relay_path` on multiline?
# if not isinstance(val, str):
# val_str = pformat(val)
# else:
val_str: str = repr(val)
if val:
_repr += f'{key}={val_str}{end_char}'
@ -358,7 +485,9 @@ class RemoteActorError(Exception):
'''
fields: str = self._mk_fields_str(
_body_fields,
_body_fields
+
self.extra_body_fields,
)
body: str = pformat_boxed_tb(
tb_str=self.tb_str,
@ -415,15 +544,6 @@ class RemoteActorError(Exception):
# raise NotImplementedError
class InternalActorError(RemoteActorError):
'''
(Remote) internal `tractor` error indicating failure of some
primitive, machinery state or lowlevel task that should never
occur.
'''
class ContextCancelled(RemoteActorError):
'''
Inter-actor task context was cancelled by either a call to
@ -433,6 +553,10 @@ class ContextCancelled(RemoteActorError):
reprol_fields: list[str] = [
'canceller',
]
extra_body_fields: list[str] = [
'cid',
'canceller',
]
@property
def canceller(self) -> tuple[str, str]|None:
'''
@ -454,7 +578,7 @@ class ContextCancelled(RemoteActorError):
|_`._cancel_task()`
'''
value = self.msgdata.get('canceller')
value: tuple[str, str]|None = self._ipc_msg.canceller
if value:
return tuple(value)
@ -468,6 +592,132 @@ class ContextCancelled(RemoteActorError):
# src_actor_uid = canceller
class MsgTypeError(
RemoteActorError,
):
'''
Equivalent of a runtime `TypeError` for IPC dialogs.
Raise when any IPC wire-message is decoded to have invalid
field values (due to type) or for other `MsgCodec` related
violations such as having no extension-type for a field with
a custom type but no `enc/dec_hook()` support.
Can be raised on the send or recv side of an IPC `Channel`
depending on the particular msg.
Msgs which cause this to be raised on the `.send()` side (aka
in the "ctl" dialog phase) include:
- `Start`
- `Started`
- `Return`
Those which cause it on on the `.recv()` side (aka the "nasty
streaming" dialog phase) are:
- `Yield`
- TODO: any embedded `.pld` type defined by user code?
Normally the source of an error is re-raised from some `.msg._codec`
decode which itself raises in a backend interchange
lib (eg. a `msgspec.ValidationError`).
'''
reprol_fields: list[str] = [
'ipc_msg',
]
extra_body_fields: list[str] = [
'cid',
'payload_msg',
]
@property
def msg_dict(self) -> dict[str, Any]:
'''
If the underlying IPC `Msg` was received from a remote
actor but was unable to be decoded to a native
`Yield`|`Started`|`Return` struct, the interchange backend
native format decoder can be used to stash a `dict`
version for introspection by the invalidating RPC task.
'''
return self.msgdata.get('_msg_dict')
@property
def payload_msg(self) -> Msg|None:
'''
Attempt to construct what would have been the original
`Msg`-with-payload subtype (i.e. an instance from the set
of msgs in `.msg.types._payload_msgs`) which failed
validation.
'''
msg_dict: dict = self.msg_dict.copy()
name: str = msg_dict.pop('msg_type')
msg_type: Msg = getattr(
msgtypes,
name,
Msg,
)
return msg_type(**msg_dict)
@property
def cid(self) -> str:
# pre-packed using `.from_decode()` constructor
return self.msgdata.get('cid')
@classmethod
def from_decode(
cls,
message: str,
msgdict: dict,
) -> MsgTypeError:
return cls(
message=message,
# NOTE: original "vanilla decode" of the msg-bytes
# is placed inside a value readable from
# `.msgdata['_msg_dict']`
_msg_dict=msgdict,
# expand and pack all RAE compat fields
# into the `._extra_msgdata` aux `dict`.
**{
k: v
for k, v in msgdict.items()
if k in _ipcmsg_keys
},
)
class StreamOverrun(
RemoteActorError,
trio.TooSlowError,
):
reprol_fields: list[str] = [
'sender',
]
'''
This stream was overrun by its sender and can be optionally
handled by app code using `MsgStream.send()/.receive()`.
'''
@property
def sender(self) -> tuple[str, str] | None:
value = self._ipc_msg.sender
if value:
return tuple(value)
# class InternalActorError(RemoteActorError):
# '''
# Boxed (Remote) internal `tractor` error indicating failure of some
# primitive, machinery state or lowlevel task that should never
# occur.
# '''
class TransportClosed(trio.ClosedResourceError):
"Underlying channel transport was closed prior to use"
@ -484,23 +734,6 @@ class NoRuntime(RuntimeError):
"The root actor has not been initialized yet"
class StreamOverrun(
RemoteActorError,
trio.TooSlowError,
):
reprol_fields: list[str] = [
'sender',
]
'''
This stream was overrun by sender
'''
@property
def sender(self) -> tuple[str, str] | None:
value = self.msgdata.get('sender')
if value:
return tuple(value)
class AsyncioCancelled(Exception):
'''
@ -518,23 +751,12 @@ class MessagingError(Exception):
'''
class MsgTypeError(MessagingError):
'''
Equivalent of a `TypeError` for an IPC wire-message
due to an invalid field value (type).
Normally this is re-raised from some `.msg._codec`
decode error raised by a backend interchange lib
like `msgspec` or `pycapnproto`.
'''
def pack_error(
exc: BaseException|RemoteActorError,
tb: str|None = None,
cid: str|None = None,
src_uid: tuple[str, str]|None = None,
) -> Error:
'''
@ -560,7 +782,8 @@ def pack_error(
):
error_msg.update(exc.msgdata)
# an onion/inception we need to pack
# an onion/inception we need to pack as a nested and relayed
# remotely boxed error.
if (
type(exc) is RemoteActorError
and (boxed := exc.boxed_type)
@ -584,7 +807,7 @@ def pack_error(
error_msg['boxed_type_str'] = 'RemoteActorError'
else:
error_msg['src_uid'] = our_uid
error_msg['src_uid'] = src_uid or our_uid
error_msg['src_type_str'] = type(exc).__name__
error_msg['boxed_type_str'] = type(exc).__name__
@ -596,7 +819,7 @@ def pack_error(
# XXX NOTE: always ensure the traceback-str is from the
# locally raised error (**not** the prior relay's boxed
# content's `.msgdata`).
# content's in `._ipc_msg.tb_str`).
error_msg['tb_str'] = tb_str
if cid is not None:
@ -606,7 +829,7 @@ def pack_error(
def unpack_error(
msg: dict[str, Any]|Error,
msg: Error,
chan: Channel|None = None,
box_type: RemoteActorError = RemoteActorError,
@ -624,16 +847,10 @@ def unpack_error(
'''
__tracebackhide__: bool = hide_tb
error_dict: dict[str, dict]|None
if not isinstance(msg, Error):
# if (
# error_dict := msg.get('error')
# ) is None:
# no error field, nothing to unpack.
return None
# retrieve the remote error's msg encoded details
# tb_str: str = error_dict.get('tb_str', '')
# retrieve the remote error's encoded details from fields
tb_str: str = msg.tb_str
message: str = (
f'{chan.uid}\n'
@ -651,6 +868,10 @@ def unpack_error(
box_type = ContextCancelled
assert boxed_type is box_type
elif boxed_type_str == 'MsgTypeError':
box_type = MsgTypeError
assert boxed_type is box_type
# TODO: already included by `_this_mod` in else loop right?
#
# we have an inception/onion-error so ensure
@ -661,12 +882,9 @@ def unpack_error(
# assert len(error_dict['relay_path']) >= 1
assert len(msg.relay_path) >= 1
# TODO: mk RAE just take the `Error` instance directly?
error_dict: dict = structs.asdict(msg)
exc = box_type(
message,
**error_dict,
ipc_msg=msg,
)
return exc