def _add_step(self, step_kind, step_label, transform_node, side_tags=()):
"""Creates a Step object and adds it to the cache."""
# Import here to avoid adding the dependency for local running scenarios.
# pylint: disable=wrong-import-order, wrong-import-position
from apache_beam.runners.dataflow.internal import apiclient
step = apiclient.Step(step_kind, self._get_unique_step_name())
self.job.proto.steps.append(step.proto)
step.add_property(PropertyNames.USER_NAME, step_label)
# Cache the node/step association for the main output of the transform node.
self._cache.cache_output(transform_node, None, step)
# If side_tags is not () then this is a multi-output transform node and we
# need to cache the (node, tag, step) for each of the tags used to access
# the outputs. This is essential because the keys used to search in the
# cache always contain the tag.
for tag in side_tags:
self._cache.cache_output(transform_node, tag, step)
# Finally, we add the display data items to the pipeline step.
# If the transform contains no display data then an empty list is added.
step.add_property(
PropertyNames.DISPLAY_DATA,
[item.get_dict() for item in
DisplayData.create_from(transform_node.transform).items])
return step
def _add_singleton_step(self, label, full_label, tag, input_step):
"""Creates a CollectionToSingleton step used to handle ParDo side inputs."""
# Import here to avoid adding the dependency for local running scenarios.
from apache_beam.runners.dataflow.internal import apiclient
step = apiclient.Step(TransformNames.COLLECTION_TO_SINGLETON, label)
self.job.proto.steps.append(step.proto)
step.add_property(PropertyNames.USER_NAME, full_label)
step.add_property(
PropertyNames.PARALLEL_INPUT,
{'@type': 'OutputReference',
PropertyNames.STEP_NAME: input_step.proto.name,
PropertyNames.OUTPUT_NAME: input_step.get_output(tag)})
step.encoding = self._get_side_input_encoding(input_step.encoding)
step.add_property(
PropertyNames.OUTPUT_INFO,
[{PropertyNames.USER_NAME: (
'%s.%s' % (full_label, PropertyNames.OUTPUT)),
PropertyNames.ENCODING: step.encoding,
PropertyNames.OUTPUT_NAME: PropertyNames.OUT}])
return step
