tomato.driverinterface_2_0 package

DriverInterface-2.0

Code author: Peter Kraus

tomato.driverinterface_2_0.in_devmap(func)

tomato.driverinterface_2_0.to_reply(func): Helper decorator for coercing tuples into Reply.

tomato.driverinterface_2_0.log_errors(func)

Helper decorator for logging all kinds of errors.

This decorator should be only used on functions in the API of the ModelInterface, as the caught exceptions will cause the driver process to exit.

pydantic model tomato.driverinterface_2_0.Attr

Bases: BaseModel

A Pydantic BaseModel used to describe device attributes.

Show JSON schema

{
   "title": "Attr",
   "type": "object",
   "properties": {
      "type": {
         "default": null,
         "title": "Type"
      },
      "rw": {
         "default": false,
         "title": "Rw",
         "type": "boolean"
      },
      "status": {
         "default": false,
         "title": "Status",
         "type": "boolean"
      },
      "units": {
         "default": null,
         "title": "Units",
         "type": "string"
      },
      "maximum": {
         "anyOf": [
            {
               "type": "number"
            },
            {
               "type": "null"
            }
         ],
         "default": null,
         "title": "Maximum"
      },
      "minimum": {
         "anyOf": [
            {
               "type": "number"
            },
            {
               "type": "null"
            }
         ],
         "default": null,
         "title": "Minimum"
      }
   }
}

Config:

arbitrary_types_allowed: bool = True

field type: type [Required]: Data type of the attribute

field rw: bool = False: Is the attribute read-write?

field status: bool = False: Should the attribute be included in component status?

field units: str = None: Default units for the attribute, optional.

field maximum: float | Quantity | None = None

Maximum value for the attribute, optional.

Constraints:

union_mode = left_to_right

field minimum: float | Quantity | None = None

Minimum value for the attribute, optional.

Constraints:

union_mode = left_to_right

class tomato.driverinterface_2_0.ModelInterface(settings=None)

Bases: object

An abstract base class specifying the driver interface.

Individual driver modules should expose a DriverInterface as a top-level import, which inherits from this abstract class. Only the methods of this class are used to interact with drivers and their components.

This class contains one abstract method, DeviceFactory(), that has to be re-implemented by the driver modules.

All methods of this class should return Reply objects (except the DeviceFactory() function). However, for better readability, a decorator function to_reply() is provided, so that the types of the return values can be explicitly defined here.

version: str = '2.0'

devmap: dict[tuple, ModelDevice]: Map of registered devices, the tuple keys are component = (address, channel)

constants: dict[str, Any]: A map that should be populated with driver-specific run-time constants.

settings: dict[str, Any]: A settings map to contain driver-specific settings such as dllpath for BioLogic

abstract DeviceFactory(key: tuple[str, str], **kwargs) → ModelDevice: A factory function which is used to pass this instance of the ModelInterface to the new ModelDevice instance.

dev_register(**kwargs)

dev_teardown(**kwargs)

dev_reset(**kwargs)

dev_set_attr(**kwargs)

dev_get_attr(**kwargs)

dev_status(**kwargs)

dev_capabilities(**kwargs)

dev_attrs(**kwargs)

cmp_register(address: str, channel: str, **kwargs: dict) → tuple[bool, str, set]

Register a new device component in this driver.

Creates a ModelDevice representing a device component, storing it in the self.devmap using the provided address and channel.

Returns the set of capabilities of the registered component as the Reply.data.

cmp_teardown(key: tuple[str, str], **kwargs: dict) → tuple[bool, str, None]

Emergency stop function.

Should set the device component into a documented, safe state. The function is to be only called in case of critical errors, or when the component is being removed, not as part of normal operation (i.e. it is not intended as a clean-up after task completion).

cmp_reset(key: tuple[str, str], **kwargs: dict) → tuple[bool, str, None]

Component reset function.

Should set the device component into a documented, safe state. This function is executed at the end of every job.

cmp_set_attr(attr: str, val: Val, key: tuple[str, str], **kwargs: dict) → tuple[bool, str, Val]

Set value of the Attr of the specified device component.

Pass-through to the ModelDevice.set_attr() function. No type or read-write validation performed here! Returns the validated or coerced value as the Reply.data.

cmp_get_attr(attr: str, key: tuple[str, str], **kwargs: dict) → tuple[bool, str, Val]

Get value of the Attr from the specified device component.

Pass-through to the ModelDevice.get_attr() function. No type coercion is done here. Returns the value as the Reply.data.

cmp_status(key: tuple[str, str], **kwargs: dict) → tuple[bool, str, dict]

Get the status report from the specified device component.

Iterates over all Attrs on the component that have status=True and returns their values in the Reply.data as a dict.

cmp_capabilities(key: tuple[str, str], **kwargs) → tuple[bool, str, set]

Returns the capabilities of the device component.

Pass-through to ModelDevice.capabilities(). Returns the set of capabilities in Reply.data.

cmp_attrs(key: tuple[str, str], **kwargs: dict) → tuple[bool, str, dict]

Query available Attrs on the specified device component.

Pass-through to the ModelDevice.attrs() function. Returns the dict of attributes as the Reply.data.

cmp_constants(key: tuple[str, str], **kwargs: dict) → tuple[bool, str, dict]

Query constants on the specified device component and this driver.

Returns the dict of constants as the Reply.data.

cmp_last_data(key: tuple[str, str], **kwargs: dict) → tuple[bool, str, None | Dataset]

Fetch the last stored data on the component.

Passthrough to ModelDevice.get_last_data(). The data in the form of a xarray.Dataset is returned as the Reply.data.

cmp_measure(key: tuple[str, str], **kwargs: dict) → tuple[bool, str, None]

Do a single measurement on the component according to its current configuration.

Fails if the component already has a running task / measurement.

task_start(key: tuple[str, str], task: Task, **kwargs) → tuple[bool, str, set | Task]

Submit a Task onto the specified device component.

Pushes the supplied Task into the Queue of the component, then starts the worker thread. Checks that the Task is among the capabilities of this component.

task_status(key: tuple[str, str], **kwargs: dict) → tuple[bool, str, dict]

Returns the task readiness status of the specified device component.

The running entry in the data slot of the Reply indicates whether a Task is running. The can_submit entry indicates whether another Task can be queued onto the device component already.

task_stop(key: tuple[str, str], **kwargs) → tuple[bool, str, Dataset | None]

Stops a running task and returns any collected data.

Pass-through to ModelDevice.stop_task() and ModelInterface.task_data().

If there is any cached data, it is returned as a xarray.Dataset in the Reply.data and the cache is cleared.

task_data(key: tuple[str, str], **kwargs) → tuple[bool, str, Dataset | None]

Return cached task data on the device component and clean the cache.

Pass-through for ModelDevice.get_data(), which should return a xarray.Dataset that is fully annotated.

This function gets called by the job thread every device.pollrate, it therefore incurs some IPC cost.

task_validate(key: tuple[str, str], task: Task, **kwargs) → tuple[bool, str, None]: Validate the provided Task for submission on the component identified by key.

status() → Reply: Returns the driver status. Currently that is the names of the components in the devmap.

reset() → Reply

Resets the driver.

Called when the driver process is quitting. Instructs all remaining tasks to stop. Warns when devices linger. Passes through to dev_reset(). This is not a pass-through to dev_teardown().

class tomato.driverinterface_2_0.ModelDevice(driver, key, **kwargs)

Bases: object

An abstract base class specifying a manager for an individual component.

This class should handle determining attributes and capabilities of the component, the reading/writing of those attributes, processing of tasks, and caching and returning of task data.

driver: ModelInterface: The parent DriverInterface instance.

key: tuple[str, str]: The key in self.driver.devmap referring to this object.

task_list: Queue: A Queue used to pass Tasks to the worker Thread.

thread: Thread: The worker Thread.

data: Dataset | None: Container for cached data on this component.

last_data: Dataset | None: Container for last datapoint on this component.

running: bool

datalock: RLock: Lock object for thread-safe data manipulation.

constants: dict[str, Any]: Constant metadata of this component.

run(): Helper function for starting the self.thread as a task.

measure(): Helper function for starting the self.thread as a measurement.

task_runner()

Target function for the self.thread when handling Tasks.

This function waits for a Task passed using self.task_list, then handles setting all Attrs using the prepare_task() function, and finally handles the main loop of the task, periodically running the do_task() function (using task.sampling_interval) until the maximum task duration (i.e. task.max_duration) is exceeded.

The self.thread is re-primed for future Tasks at the end of this function.

meas_runner()

Target function for the self.thread when performing one shot measurements.

Performs the measurement using self.do_measure(). Resets self.thread for future Tasks.

prepare_task(task: Task, **kwargs: dict): Given a Task, prepare this component for execution by setting all Attrs as specified in the task.task_params dictionary.

do_task(task: Task, **kwargs: dict)

Periodically called task execution function.

This function is responsible for updating self.data with new data, i.e. performing the measurement. It should also update the value of self.last_data, so that the component status is consistent with the cached data.

abstract do_measure(**kwargs: dict) → None

One shot execution worker function.

This function is performs a measurement using the current configuration of self.attrs, and stores the result in self.last_data.

stop_task(**kwargs: dict): Stops the currently running task.

abstract set_attr(attr: str, val: Val, **kwargs: dict) → Val

Sets the specified Attr to val.

This function should handle any data type coercion and validation using e.g. Attr.maximum and Attr.minimum.

Returns the coerced value coresponding to val.

abstract get_attr(attr: str, **kwargs: dict) → Val: Reads the value of the specified Attr.

get_data(**kwargs: dict) → Dataset: Returns the cached self.data as a xarray.Dataset before clearing the cache.

get_last_data(**kwargs: dict) → Dataset: Returns the last_data object as a xarray.Dataset.

abstract attrs() → dict[str, Attr]: Returns a dict of all available Attrs.

abstract capabilities() → set: Returns a set of all supported techniques.

status(**kwargs) → dict[str, Val]: Compiles a status report from Attrs marked as status=True.

reset(**kwargs) → None: Resets the component to an initial status.