async def create_selection(self, source, index=None, name=None):
py_typecheck.check_type(source, FederatingExecutorValue)
py_typecheck.check_type(source.type_signature,
computation_types.NamedTupleType)
if name is not None:
name_to_index = dict((n, i) for i, (
n,
t) in enumerate(anonymous_tuple.to_elements(source.type_signature)))
index = name_to_index[name]
if isinstance(source.internal_representation,
anonymous_tuple.AnonymousTuple):
val = source.internal_representation
selected = val[index]
return FederatingExecutorValue(selected, source.type_signature[index])
elif isinstance(source.internal_representation,
executor_value_base.ExecutorValue):
if type_utils.type_tree_contains_types(source.type_signature,
computation_types.FederatedType):
raise ValueError(
'FederatingExecutorValue {} has violated its contract; '
'it is embedded in another executor and yet its type '
'has placement. The embedded value is {}, with type '
'signature {}.'.format(source, source.internal_representation,
source.type_signature))
val = source.internal_representation
child = self._target_executors[None][0]
return FederatingExecutorValue(
await child.create_selection(val, index=index),
source.type_signature[index])
else:
raise ValueError('Unexpected internal representation while creating '
'selection. Expected one of `AnonymousTuple` or value '
'embedded in target executor, received {}'.format(
source.internal_representation))
def federated_value(self, value, placement):
"""Implements `federated_value` as defined in `api/intrinsics.py`."""
value = value_impl.to_value(value, None, self._context_stack)
if type_utils.type_tree_contains_types(value.type_signature,
computation_types.FederatedType):
raise TypeError('Cannt place value {} containing federated types at '
'another placement; requested to be placed at {}.'.format(
value, placement))
value = value_impl.ValueImpl.get_comp(value)
comp = building_block_factory.create_federated_value(value, placement)
return value_impl.ValueImpl(comp, self._context_stack)