johnyangk commented on a change in pull request #122: [NEMO-213] Use Beam's DoFnRunners to execute DoFn URL: https://github.com/apache/incubator-nemo/pull/122#discussion_r223662932
########## File path: compiler/frontend/beam/src/main/java/org/apache/nemo/compiler/frontend/beam/transform/StatefulDoFnTransform.java ########## @@ -0,0 +1,169 @@ +/* + * Copyright (C) 2018 Seoul National University + * + * Licensed 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. + */ +package org.apache.nemo.compiler.frontend.beam.transform; + +import org.apache.beam.runners.core.*; +import org.apache.beam.runners.core.construction.SerializablePipelineOptions; +import org.apache.beam.sdk.coders.Coder; +import org.apache.beam.sdk.options.PipelineOptions; +import org.apache.beam.sdk.transforms.DoFn; +import org.apache.beam.sdk.transforms.reflect.DoFnInvoker; +import org.apache.beam.sdk.transforms.reflect.DoFnInvokers; +import org.apache.beam.sdk.util.WindowedValue; +import org.apache.beam.sdk.values.KV; +import org.apache.beam.sdk.values.PCollectionView; +import org.apache.beam.sdk.values.TupleTag; +import org.apache.beam.sdk.values.WindowingStrategy; +import org.apache.nemo.common.ir.OutputCollector; +import org.apache.nemo.common.ir.vertex.transform.Transform; +import org.apache.nemo.compiler.frontend.beam.NemoPipelineOptions; + +import java.util.Collection; +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +/** + * Stateful DoFn transform implementation. + * This implementation supposes that the inputs are KV. + * We then process the inputs that have the same key in the same doFnRunner for stateful processing. + * + * @param <K> key type. + * @param <InputT> input type. + * @param <OutputT> output type. + */ +public final class StatefulDoFnTransform<K, InputT, OutputT> implements + Transform<WindowedValue<KV<K, InputT>>, WindowedValue<OutputT>> { + + private OutputCollector<WindowedValue<OutputT>> outputCollector; + private final TupleTag<OutputT> mainOutputTag; + private final List<TupleTag<?>> additionalOutputTags; + private final Collection<PCollectionView<?>> sideInputs; + private final WindowingStrategy<?, ?> windowingStrategy; + private final DoFn<KV<K, InputT>, OutputT> doFn; + private final SerializablePipelineOptions serializedOptions; + private final Coder<KV<K, InputT>> inputCoder; + private final Map<TupleTag<?>, Coder<?>> outputCoders; + + private transient SideInputReader sideInputReader; + private transient NemoPipelineOptions options; + private transient DoFnRunners.OutputManager outputManager; + + private final Map<K, DoFnRunner<KV<K, InputT>, OutputT>> doFnRunnerMap; + private final Map<K, DoFnInvoker<KV<K, InputT>, OutputT>> doFnInvokerMap; + + /** + * Stateful DoFn Transform Constructor. + * + * @param doFn doFn. + * @param options Pipeline options. + */ + public StatefulDoFnTransform(final DoFn<KV<K, InputT>, OutputT> doFn, + final Coder<KV<K, InputT>> inputCoder, + final Map<TupleTag<?>, Coder<?>> outputCoders, + final TupleTag<OutputT> mainOutputTag, + final List<TupleTag<?>> additionalOutputTags, + final WindowingStrategy<?, ?> windowingStrategy, + final Collection<PCollectionView<?>> sideInputs, + final PipelineOptions options) { + this.doFn = doFn; + this.inputCoder = inputCoder; + this.outputCoders = outputCoders; + this.mainOutputTag = mainOutputTag; + this.additionalOutputTags = additionalOutputTags; + this.sideInputs = sideInputs; + this.serializedOptions = new SerializablePipelineOptions(options); + this.windowingStrategy = windowingStrategy; + this.doFnRunnerMap = new HashMap<>(); + this.doFnInvokerMap = new HashMap<>(); + } + + @Override + public void prepare(final Context context, final OutputCollector<WindowedValue<OutputT>> oc) { + // deserialize pipeline option + this.options = serializedOptions.get().as(NemoPipelineOptions.class); + + this.outputCollector = oc; + + // create output manager + outputManager = new DefaultOutputManager<>( + outputCollector, context, mainOutputTag); + + // create side input reader + sideInputReader = NullSideInputReader.of(sideInputs); + if (!sideInputs.isEmpty()) { + sideInputReader = new BroadcastGlobalValueSideInputReader(context, sideInputs); + } + } + + @Override + public void onData(final WindowedValue<KV<K, InputT>> data) { + final K key = data.getValue().getKey(); + DoFnRunner<KV<K, InputT>, OutputT> doFnRunner = doFnRunnerMap.get(key); + + if (doFnRunner == null) { + // TODO #: Implement stateInternalFactory Review comment: TODO number missing. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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