| # |
| # Licensed to the Apache Software Foundation (ASF) under one or more |
| # contributor license agreements. See the NOTICE file distributed with |
| # this work for additional information regarding copyright ownership. |
| # The ASF licenses this file to You under the Apache License, Version 2.0 |
| # (the "License"); you may not use this file except in compliance with |
| # the License. You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| # |
| |
| """Utility class for serializing pipelines via the runner API. |
| |
| For internal use only; no backwards-compatibility guarantees. |
| """ |
| |
| from __future__ import absolute_import |
| |
| from builtins import object |
| |
| from apache_beam import coders |
| from apache_beam import pipeline |
| from apache_beam import pvalue |
| from apache_beam.portability.api import beam_fn_api_pb2 |
| from apache_beam.portability.api import beam_runner_api_pb2 |
| from apache_beam.transforms import core |
| |
| |
| class Environment(object): |
| """A wrapper around the environment proto. |
| |
| Provides consistency with how the other componentes are accessed. |
| """ |
| def __init__(self, proto): |
| self._proto = proto |
| |
| def to_runner_api(self, context): |
| return self._proto |
| |
| @staticmethod |
| def from_runner_api(proto, context): |
| return Environment(proto) |
| |
| |
| class _PipelineContextMap(object): |
| """This is a bi-directional map between objects and ids. |
| |
| Under the hood it encodes and decodes these objects into runner API |
| representations. |
| """ |
| def __init__(self, context, obj_type, proto_map=None): |
| self._pipeline_context = context |
| self._obj_type = obj_type |
| self._obj_to_id = {} |
| self._id_to_obj = {} |
| self._id_to_proto = dict(proto_map) if proto_map else {} |
| self._counter = 0 |
| |
| def _unique_ref(self, obj=None, label=None): |
| self._counter += 1 |
| return "ref_%s_%s_%s" % ( |
| self._obj_type.__name__, label or type(obj).__name__, self._counter) |
| |
| def populate_map(self, proto_map): |
| for id, proto in self._id_to_proto.items(): |
| proto_map[id].CopyFrom(proto) |
| |
| def get_id(self, obj, label=None): |
| if obj not in self._obj_to_id: |
| id = self._unique_ref(obj, label) |
| self._id_to_obj[id] = obj |
| self._obj_to_id[obj] = id |
| self._id_to_proto[id] = obj.to_runner_api(self._pipeline_context) |
| return self._obj_to_id[obj] |
| |
| def get_proto(self, obj, label=None): |
| return self._id_to_proto[self.get_id(obj, label)] |
| |
| def get_by_id(self, id): |
| if id not in self._id_to_obj: |
| self._id_to_obj[id] = self._obj_type.from_runner_api( |
| self._id_to_proto[id], self._pipeline_context) |
| return self._id_to_obj[id] |
| |
| def __getitem__(self, id): |
| return self.get_by_id(id) |
| |
| def __contains__(self, id): |
| return id in self._id_to_proto |
| |
| |
| class PipelineContext(object): |
| """For internal use only; no backwards-compatibility guarantees. |
| |
| Used for accessing and constructing the referenced objects of a Pipeline. |
| """ |
| |
| _COMPONENT_TYPES = { |
| 'transforms': pipeline.AppliedPTransform, |
| 'pcollections': pvalue.PCollection, |
| 'coders': coders.Coder, |
| 'windowing_strategies': core.Windowing, |
| 'environments': Environment, |
| } |
| |
| def __init__(self, proto=None, default_environment=None): |
| if isinstance(proto, beam_fn_api_pb2.ProcessBundleDescriptor): |
| proto = beam_runner_api_pb2.Components( |
| coders=dict(proto.coders.items()), |
| windowing_strategies=dict(proto.windowing_strategies.items()), |
| environments=dict(proto.environments.items())) |
| for name, cls in self._COMPONENT_TYPES.items(): |
| setattr( |
| self, name, _PipelineContextMap( |
| self, cls, getattr(proto, name, None))) |
| if default_environment: |
| self._default_environment_id = self.environments.get_id( |
| Environment(default_environment)) |
| else: |
| self._default_environment_id = None |
| |
| @staticmethod |
| def from_runner_api(proto): |
| return PipelineContext(proto) |
| |
| def to_runner_api(self): |
| context_proto = beam_runner_api_pb2.Components() |
| for name in self._COMPONENT_TYPES: |
| getattr(self, name).populate_map(getattr(context_proto, name)) |
| return context_proto |
| |
| def default_environment_id(self): |
| return self._default_environment_id |