kennknowles commented on code in PR #38230: URL: https://github.com/apache/beam/pull/38230#discussion_r3189574401
########## runners/core-java/src/main/java/org/apache/beam/runners/core/CombinedMetadata.java: ########## @@ -0,0 +1,87 @@ +/* + * 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. + */ +package org.apache.beam.runners.core; + +import com.google.auto.value.AutoValue; +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; +import org.apache.beam.model.fnexecution.v1.BeamFnApi; +import org.apache.beam.sdk.coders.AtomicCoder; +import org.apache.beam.sdk.values.CausedByDrain; + +/** + * Encapsulates metadata that propagates with elements in the pipeline. + * + * <p>This metadata is sent along with elements. It currently includes fields like {@link + * CausedByDrain}, and is designed to be extensible to support future metadata fields such as + * OpenTelemetry context or CDC (Change Data Capture) kind. + * + * <p>The purpose of this class is to group targeted metadata fields together. This makes it easier + * to define combination strategies (e.g., when accumulating state in {@code ReduceFnRunner}) when + * multiple elements are merged or grouped, without having to extend method signatures or state + * handling for every new metadata field. + */ +@AutoValue +public abstract class CombinedMetadata { + public abstract CausedByDrain causedByDrain(); + + public static CombinedMetadata create(CausedByDrain causedByDrain) { + return new AutoValue_CombinedMetadata(causedByDrain); + } + + public static CombinedMetadata createDefault() { + return create(CausedByDrain.NORMAL); + } + + public static class Coder extends AtomicCoder<CombinedMetadata> { + private static final Coder INSTANCE = new Coder(); + + public static Coder of() { + return INSTANCE; + } + + @Override + public void encode(CombinedMetadata value, OutputStream outStream) throws IOException { + BeamFnApi.Elements.ElementMetadata proto = + BeamFnApi.Elements.ElementMetadata.newBuilder() + .setDrain( + value.causedByDrain() == CausedByDrain.CAUSED_BY_DRAIN + ? BeamFnApi.Elements.DrainMode.Enum.DRAINING + : BeamFnApi.Elements.DrainMode.Enum.NOT_DRAINING) + .build(); + proto.writeDelimitedTo(outStream); Review Comment: Is this implemention the same as using `ProtoCoder.of(ElementMetadata.class)` ? https://github.com/apache/beam/blob/16609ed210b059946638bad019f3f05918bf9bdf/sdks/java/extensions/protobuf/src/main/java/org/apache/beam/sdk/extensions/protobuf/ProtoCoder.java#L116 ########## runners/core-java/src/main/java/org/apache/beam/runners/core/CombinedMetadataCombiner.java: ########## @@ -0,0 +1,78 @@ +/* + * 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. + */ +package org.apache.beam.runners.core; + +import org.apache.beam.sdk.transforms.Combine.CombineFn; +import org.apache.beam.sdk.values.CausedByDrain; + +/** Combiner for CombinedMetadata. */ +class CombinedMetadataCombiner Review Comment: Pretty sure this is the same as `BinaryCombineFn` default implementations. But since I hate inheritance, I'm happy to have it spelled out here. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
