[GitHub] [beam] TheNeuralBit commented on a diff in pull request #22216: BEAM-13592 Add getOrderingKey in o.a.b.sdk.io.gcp.pubsub.PubsubMessage

[GitBox <gi...@apache.org>]

TheNeuralBit commented on code in PR #22216:
URL: https://github.com/apache/beam/pull/22216#discussion_r951822289


##########
sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/pubsub/PubsubMessageCoder.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.sdk.io.gcp.pubsub;
+
+import com.google.protobuf.Timestamp;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Map;
+import org.apache.beam.sdk.coders.ByteArrayCoder;
+import org.apache.beam.sdk.coders.Coder;
+import org.apache.beam.sdk.coders.CustomCoder;
+import org.apache.beam.sdk.coders.MapCoder;
+import org.apache.beam.sdk.coders.NullableCoder;
+import org.apache.beam.sdk.coders.StringUtf8Coder;
+import org.apache.beam.sdk.extensions.protobuf.ProtoCoder;
+import org.apache.beam.sdk.values.TypeDescriptor;
+
+/** A coder for PubsubMessage including all fields of a PubSub message from server. */
+@SuppressWarnings({
+  "nullness" // TODO(https://github.com/apache/beam/issues/20497)
+})
+public class PubsubMessageCoder extends CustomCoder<PubsubMessage> {

Review Comment:
   +1 for giving this the comically long, specific name to be consistent



##########
sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/pubsub/PubsubCoderProviderRegistrar.java:
##########
@@ -37,6 +37,7 @@ public List<CoderProvider> getCoderProviders() {
             TypeDescriptor.of(PubsubMessage.class), PubsubMessageWithMessageIdCoder.of()),
         CoderProviders.forCoder(
             TypeDescriptor.of(PubsubMessage.class),
-            PubsubMessageWithAttributesAndMessageIdCoder.of()));
+            PubsubMessageWithAttributesAndMessageIdCoder.of()),
+        CoderProviders.forCoder(TypeDescriptor.of(PubsubMessage.class), PubsubMessageCoder.of()));

Review Comment:
   Thanks! I dug into the infrastructure here, and it looks like we will always just use the _first_ coder registered for a given type, so I think registering these other three will be a no-op. In theory a coder could raise `CannotProvideCoderException` and we'd move on to the next one: https://github.com/apache/beam/blob/4ffeae4d2b800f2df36d2ea2eab549f2204d5691/sdks/java/core/src/main/java/org/apache/beam/sdk/coders/CoderRegistry.java#L678
   
   but that's not going to happen here, `PubsubMessageWithAttributesCoder` will never do that.
   
   I think the actually import change is adding `readMessagesWithAttributesAndMessageIdAndOrderingKey` with the `setCoder` call.
   
   It's worth noting that what we specify here will be used as the default in any `PCollection<PubsubMessage>` that's not created by one of the `PubsubIO` helper methods. So we should consider making it the one that will _always work_. There are implications for breaking pipeline update though if we change the default. My suggestion:
   - Leave this as-is for now (don't add the new coder)
   - We can file an issue to follow-up on changing this
   
   (I gathered some context by looking at https://github.com/apache/beam/pull/8370, and also spoke to @lcwik)



-- 
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: github-unsubscribe@beam.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org