def _read_side_inputs(self, tags_and_types):
# type: (...) -> Iterator[apache_sideinputs.SideInputMap]
"""Generator reading side inputs in the order prescribed by tags_and_types.
Args:
tags_and_types: List of tuples (tag, type). Each side input has a string
tag that is specified in the worker instruction. The type is actually
a boolean which is True for singleton input (read just first value)
and False for collection input (read all values).
Yields:
With each iteration it yields the result of reading an entire side source
either in singleton or collection mode according to the tags_and_types
argument.
"""
# Only call this on the old path where side_input_maps was not
# provided directly.
assert self.side_input_maps is None
# We will read the side inputs in the order prescribed by the
# tags_and_types argument because this is exactly the order needed to
# replace the ArgumentPlaceholder objects in the args/kwargs of the DoFn
# getting the side inputs.
#
# Note that for each tag there could be several read operations in the
# specification. This can happen for instance if the source has been
# sharded into several files.
for i, (side_tag, view_class, view_options) in enumerate(tags_and_types):
sources = []
# Using the side_tag in the lambda below will trigger a pylint warning.
# However in this case it is fine because the lambda is used right away
# while the variable has the value assigned by the current iteration of
# the for loop.
# pylint: disable=cell-var-from-loop
for si in filter(lambda o: o.tag == side_tag, self.spec.side_inputs):
if not isinstance(si, operation_specs.WorkerSideInputSource):
raise NotImplementedError('Unknown side input type: %r' % si)
sources.append(si.source)
# The tracking of time spend reading and bytes read from side inputs is
# behind an experiment flag to test its performance impact.
si_counter = opcounters.SideInputReadCounter(
self.counter_factory,
self.state_sampler,
declaring_step=self.name_context.step_name,
# Inputs are 1-indexed, so we add 1 to i in the side input id
input_index=i + 1)
iterator_fn = sideinputs.get_iterator_fn_for_sources(
sources, read_counter=si_counter)
# Backwards compatibility for pre BEAM-733 SDKs.
if isinstance(view_options, tuple):
if view_class == pvalue.AsSingleton:
has_default, default = view_options
view_options = {'default': default} if has_default else {}
else:
view_options = {}
yield apache_sideinputs.SideInputMap(
view_class, view_options, sideinputs.EmulatedIterable(iterator_fn))
def _pvalue_to_value(self, view, values):
"""Given a side input view, returns the associated value in requested form.
Args:
view: SideInput for the requested side input.
values: Iterable values associated with the side input.
Returns:
The side input in its requested form.
Raises:
ValueError: If values cannot be converted into the requested form.
"""
return sideinputs.SideInputMap(type(view), view._view_options(), values)
def _pvalue_to_value(self, side_input, values):
"""Given a side input, returns the associated value in its requested form.
Args:
side_input: _UnpickledSideInput object.
values: Iterable values associated with the side input.
Returns:
The side input in its requested form.
Raises:
ValueError: If values cannot be converted into the requested form.
"""
return sideinputs.SideInputMap(type(side_input),
side_input._view_options(), values)
def _read_side_inputs(self, tags_and_types):
"""Generator reading side inputs in the order prescribed by tags_and_types.
Args:
tags_and_types: List of tuples (tag, type). Each side input has a string
tag that is specified in the worker instruction. The type is actually
a boolean which is True for singleton input (read just first value)
and False for collection input (read all values).
Yields:
With each iteration it yields the result of reading an entire side source
either in singleton or collection mode according to the tags_and_types
argument.
"""
# We will read the side inputs in the order prescribed by the
# tags_and_types argument because this is exactly the order needed to
# replace the ArgumentPlaceholder objects in the args/kwargs of the DoFn
# getting the side inputs.
#
# Note that for each tag there could be several read operations in the
# specification. This can happen for instance if the source has been
# sharded into several files.
for side_tag, view_class, view_options in tags_and_types:
sources = []
# Using the side_tag in the lambda below will trigger a pylint warning.
# However in this case it is fine because the lambda is used right away
# while the variable has the value assigned by the current iteration of
# the for loop.
# pylint: disable=cell-var-from-loop
for si in itertools.ifilter(lambda o: o.tag == side_tag,
self.spec.side_inputs):
if not isinstance(si, operation_specs.WorkerSideInputSource):
raise NotImplementedError('Unknown side input type: %r' %
si)
sources.append(si.source)
iterator_fn = sideinputs.get_iterator_fn_for_sources(sources)
# Backwards compatibility for pre BEAM-733 SDKs.
if isinstance(view_options, tuple):
if view_class == pvalue.AsSingleton:
has_default, default = view_options
view_options = {'default': default} if has_default else {}
else:
view_options = {}
yield apache_sideinputs.SideInputMap(
view_class, view_options,
sideinputs.EmulatedIterable(iterator_fn))
