Source code for labgrid.binding

import enum
from functools import wraps
from typing import Any, Dict

import attr


[docs]@attr.s(eq=False) class StateError(Exception): msg = attr.ib(validator=attr.validators.instance_of(str))
[docs]@attr.s(eq=False) class BindingError(Exception): msg = attr.ib(validator=attr.validators.instance_of(str))
[docs]@enum.unique class BindingState(enum.Enum): error = -1 idle = 0 bound = 1 active = 2
[docs]@attr.s(eq=False) class BindingMixin: """ Handles the binding and activation of drivers and their supplying resources and drivers. One client can be bound to many suppliers, and one supplier can be bound by many clients. Conflicting access to one supplier can be avoided by deactivating conflicting clients before activation (using the resolve_conflicts callback). """ bindings: Dict[str, Any] = {} # these are controlled by the Target target = attr.ib() name = attr.ib( validator=attr.validators.optional(attr.validators.instance_of(str))) state = attr.ib(default=BindingState.idle, init=False)
[docs] def __attrs_post_init__(self): self.suppliers = set() self.clients = set() target = self.target if target is not None: # bind will set it again if successful self.target = None target.bind(self) assert self.target is not None
@property def display_name(self): if self.name: return f"{self.__class__.__name__}(target={self.target.name}, name={self.name})" return f"{self.__class__.__name__}(target={self.target.name})"
[docs] def on_supplier_bound(self, supplier): """Called by the Target after a new supplier has been bound""" pass
[docs] def on_client_bound(self, client): """Called by the Target after a new client has been bound""" pass
[docs] def on_activate(self): """Called by the Target when this object has been activated""" pass
[docs] def on_deactivate(self): """Called by the Target when this object has been deactivated""" pass
[docs] def resolve_conflicts(self, client): """ Called by the Target to allow this object to deactivate conflicting clients. """ pass
[docs] @classmethod def check_active(cls, func): @wraps(func) def wrapper(self, *_args, **_kwargs): if self.state is not BindingState.active: raise StateError( f'{self} has not been activated, {func.__qualname__} cannot be called in state "{self.state.name}"' # pylint: disable=line-too-long ) return func(self, *_args, **_kwargs) return wrapper
[docs] @classmethod def check_bound(cls, func): @wraps(func) def wrapper(self, *_args, **_kwargs): if self.state is BindingState.active: raise StateError( f'{self} is active, but must be deactivated to call {func.__qualname__}' # pylint: disable=line-too-long ) elif self.state is not BindingState.bound: raise StateError( f'{self} has not been bound, {func.__qualname__} cannot be called in state "{self.state.name}"' # pylint: disable=line-too-long ) return func(self, *_args, **_kwargs) return wrapper
[docs] class NamedBinding: """ Marks a binding (or binding set) as requiring an explicit name. """
[docs] def __init__(self, value): self.value = value
[docs] def __repr__(self): return f"Binding.Named({repr(self.value)})"