New signal typing

[coretl]

Rewrite the type support, and use a plugin Connector architecture to support reconnection for PVI and Tango.

Fixes #472, fixes #562, fixes #535, fixes #505, fixes #373, fixes #601

Required for #551

Breaking changes

pvi structure changes

Structure now read from .value rather than .pvi. Supported in FastCS. Requires at least PandABlocks-ioc 0.10.0

StrictEnum is now requried for all strictly checked Enums

# old
from enum import Enum
class MyEnum(str, Enum):
    ONE = "one"
    TWO = "two"
# new
from ophyd_async.core import StrictEnum
class MyEnum(StrictEnum):
    ONE = "one"
    TWO = "two"

SubsetEnum is now an Enum subclass:

from ophyd_async.core import SubsetEnum
# old
MySubsetEnum = SubsetEnum["one", "two"]
# new
class MySubsetEnum(SubsetEnum):
    ONE = "one"
    TWO = "two"

Use python primitives for scalar types instead of numpy types

# old
import numpy as np
x = epics_signal_rw(np.int32, "PV")
# new
x = epics_signal_rw(int, "PV")

Use Array1D for 1D arrays instead of npt.NDArray

import numpy as np
# old
import numpy.typing as npt
x = epics_signal_rw(npt.NDArray[np.int32], "PV")
# new
from ophyd_async.core import Array1D
x = epics_signal_rw(Array1D[np.int32], "PV")

Use Sequence[str] for arrays of strings instead of npt.NDArray[np.str_]

import numpy as np
# old
import numpy.typing as npt
x = epics_signal_rw(npt.NDArray[np.str_], "PV")
# new
from collections.abc import Sequence
x = epics_signal_rw(Sequence[str], "PV")

MockSignalBackend requires a real backend

# old
fake_set_signal = SignalRW(MockSignalBackend(float))
# new
fake_set_signal = soft_signal_rw(float)
await fake_set_signal.connect(mock=True)

get_mock_put is no longer passed timeout as it is handled in Signal

# old
get_mock_put(driver.capture).assert_called_once_with(Writing.ON, wait=ANY, timeout=ANY)
# new
get_mock_put(driver.capture).assert_called_once_with(Writing.ON, wait=ANY)

super().__init__ required for Device subclasses

# old
class MyDevice(Device):
    def __init__(self, name: str = ""):
        self.signal, self.backend_put = soft_signal_r_and_setter(int)
# new
class MyDevice(Device):
    def __init__(self, name: str = ""):
        self.signal, self.backend_put = soft_signal_r_and_setter(int)
        super().__init__(name=name)

Arbitrary BaseModels not supported, pending use cases for them

The Table type has been suitable for everything we have seen so far, if you need an arbitrary BaseModel subclass then please make an issue

Child Devices set parent on attach, and can't be public children of more than one parent

class SourceDevice(Device):
    def __init__(self, name: str = ""):
        self.signal = soft_signal_rw(int)
        super().__init__(name=name)

# old
class ReferenceDevice(Device):
    def __init__(self, signal: SignalRW[int], name: str = ""):
        self.signal = signal
        super().__init__(name=name)

    def set(self, value) -> AsyncStatus:
        return self.signal.set(value + 1)
# new
class ReferenceDevice(Device):
    def __init__(self, signal: SignalRW[int], name: str = ""):
        self._signal = signal
        super().__init__(name=name)

    def set(self, value) -> AsyncStatus:
        return self._signal.set(value + 1)

[coretl]

Apologies, another unreviewable PR, but if you start from the tests you can see the changes needed

[evalott100]

Most of these are discussion points more than "requested changes". I definitely like abstracting out connection logic.

[evalott100]

I played around with trying to find the nicest way to default type connector for wayyyy to long 😅

[coretl]

@evalott100 if you get a chance please could you review core._device.py and core._signal.py

[burkeds]

import numpy as np
# old
import numpy.typing as npt
x = epics_signal_rw(npt.NDArray[np.int32], "PV")
# new
from ophyd_async.core import Array1D
x = epics_signal_rw(Array1D[np.int32], "PV")

@coretl I suspect this will break type enforcement on the tango backend. PyTango will read in non-scalar values as numpy arrays. This change will necessitate a rewrite of get_trl_descriptor. I really don't like this method. I think I want to refactor it and put its type enforcement elsewhere. What do you think?

[evalott100]

Will examine further tomorrow.

[evalott100]

I'll do a patch release of event model soon which allows |

https://github.com/bluesky/ophyd-async/pull/594/files#r1784069033

[rtuck99]

Seems like assert_configuration() (and presumably also assert_reading()) are broken for numpy array types. I guess they probably were already broken before these changes, but one of the tests in dodal uses assert_configuration and I encountered this as I'm currently in the process of going through dodal and mx-bluesky to test out this PR.
I will keep you posted if I find any other issues.

[Tom-Willemsen]

Just tried this branch on our devices at ISIS, I'm getting a timeout when doing trigger on a device, despite explicitly specifying no timeout.

Problematic line is something like:

await dae.controls.end_run.trigger(wait=True, timeout=None)

where the relevant signal will give an EPICS completion callback eventually, but can be quite slow (~30s). My understanding was that specifying timeout=None should explicitly say "no timeout", and this seemed to work previously, but on this branch I'm seeing a timeout error. Full stack trace listed in this PR.