gemelen commented on code in PR #22216: URL: https://github.com/apache/beam/pull/22216#discussion_r918917596
########## 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> { + // A message's payload cannot be null + private static final Coder<byte[]> PAYLOAD_CODER = ByteArrayCoder.of(); + // A message's attributes can be null. + private static final Coder<Map<String, String>> ATTRIBUTES_CODER = + NullableCoder.of(MapCoder.of(StringUtf8Coder.of(), StringUtf8Coder.of())); + // A message's messageId cannot be null + private static final Coder<String> MESSAGE_ID_CODER = StringUtf8Coder.of(); + // A message's publish time, populated by server + private static final Coder<Timestamp> PUBLISH_TIME_CODER = ProtoCoder.of(Timestamp.class); + // A message's ordering key can be null + private static final Coder<String> ORDERING_KEY_CODER = NullableCoder.of(StringUtf8Coder.of()); + + public static Coder<PubsubMessage> of(TypeDescriptor<PubsubMessage> ignored) { + return of(); + } + + public static PubsubMessageCoder of() { + return new PubsubMessageCoder(); + } + + @Override + public void encode(PubsubMessage value, OutputStream outStream) throws IOException { + PAYLOAD_CODER.encode(value.getPayload(), outStream); + ATTRIBUTES_CODER.encode(value.getAttributeMap(), outStream); + MESSAGE_ID_CODER.encode(value.getMessageId(), outStream); + // TODO(discuss what to do with publish_time field) Review Comment: I'd like to discuss if my approach here is correct: This changeset aims to add only ordering key property of a PubsubMessage, but it's not possible to omit `publish_time` since it precedes `ordering_key` in protobuf schema [PubsubMessage](https://cloud.google.com/pubsub/docs/reference/rpc/google.pubsub.v1#google.pubsub.v1.PubsubMessage) and thus in byte stream. Changeset doesn't expose `publish_time` and omits it after byte stream deserialization in `decode` function. Also, in `encode` function of the relevant coder I use meaningless default instance of [protobuf.Timestamp](https://developers.google.com/protocol-buffers/docs/reference/google.protobuf#google.protobuf.Timestamp) just to add required amount of bytes into serialized form of a PubsubMessage. So, is it correct way or you could suggest what needs to be done with this field instead? -- 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]
