def _bind_comp_as_reference(comp):
fc_context = context_stack_impl.context_stack.current
if not isinstance(fc_context, symbol_binding_context.SymbolBindingContext):
raise context_base.ContextError(
f'Attempted to construct an intrinsic in context {fc_context} which '
' does not support binding references.')
return fc_context.bind_computation_to_reference(comp)
def _check_symbol_binding_context(context: context_base.Context):
if not isinstance(context, symbol_binding_context.SymbolBindingContext):
raise context_base.ContextError('TFF values should only be materialized '
'inside a context which can bind '
'references, generally a '
'`FederatedComputationContext`. Attempted '
'to materialize a TFF value in a context '
'{c} of type {t}.'.format(
c=context, t=type(context)))
def _bind_computation_to_reference(comp, op: str):
context = context_stack_impl.context_stack.current
if not isinstance(context, symbol_binding_context.SymbolBindingContext):
raise context_base.ContextError(
'`tff.Value`s should only be used in contexts which can bind '
'references, generally a `FederatedComputationContext`. Attempted '
f'to bind the result of {op} in a context {context} of '
f'type {type(context)}.')
return context.bind_computation_to_reference(comp)
def get_session_token() -> tf.Tensor:
"""Returns a string tensor identifying the current session."""
context = context_stack_impl.context_stack.current
if not isinstance(context, TensorFlowComputationContext):
raise context_base.ContextError(
'Session tokens can only be retrieved from within the '
'`TensorFlowComputationContext (in a `@tff.tf_computation`). '
f'Instead, the context {context} of type {type(context)} was found.')
return context.session_token
def _bind_comp_as_reference(self, comp):
fc_context = self._context_stack.current
if not isinstance(fc_context, symbol_binding_context.SymbolBindingContext):
raise context_base.ContextError(
'Intrsinics cannot be constructed without '
'the ability to bind references to the '
'generated ASTs; attempted to construct '
'an intrinsic in context {c} which '
'exposes no such mechanism.'.format(c=fc_context))
return fc_context.bind_computation_to_reference(comp)
