nsivabalan commented on a change in pull request #2598: URL: https://github.com/apache/hudi/pull/2598#discussion_r584213651
########## File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/decoders/KafkaAvroSchemaDeserializer.java ########## @@ -0,0 +1,175 @@ +/* + * 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.hudi.utilities.decoders; + +import io.confluent.kafka.schemaregistry.client.rest.exceptions.RestClientException; +import io.confluent.kafka.serializers.AbstractKafkaAvroDeserializer; +import io.confluent.kafka.serializers.KafkaAvroDeserializer; +import io.confluent.kafka.serializers.NonRecordContainer; +import org.apache.avro.Schema; +import org.apache.avro.generic.GenericDatumReader; +import org.apache.avro.io.DatumReader; +import org.apache.avro.io.DecoderFactory; +import org.apache.hudi.common.config.TypedProperties; +import org.apache.hudi.utilities.UtilHelpers; +import org.apache.hudi.utilities.schema.SchemaProvider; +import org.apache.kafka.common.errors.SerializationException; +import org.codehaus.jackson.node.JsonNodeFactory; + +import java.io.IOException; +import java.nio.ByteBuffer; +import java.util.Map; +import java.util.Map.Entry; +import java.util.Objects; + +/** + * Extending {@link KafkaAvroSchemaDeserializer} as we need to be able to inject reader schema during deserialization. + */ +public class KafkaAvroSchemaDeserializer extends KafkaAvroDeserializer { + + private static final String SCHEMA_PROVIDER_CLASS_PROP = "hoodie.deltastreamer.schemaprovider.class"; + + private final DecoderFactory decoderFactory = DecoderFactory.get(); + private Schema sourceSchema; + + public KafkaAvroSchemaDeserializer() {} + + @Override + public void configure(Map<String, ?> configs, boolean isKey) { + super.configure(configs, isKey); + try { + TypedProperties props = getConvertToTypedProperties(configs); + SchemaProvider schemaProvider = UtilHelpers.createSchemaProvider( + props.getString(SCHEMA_PROVIDER_CLASS_PROP), props, null); + sourceSchema = Objects.requireNonNull(schemaProvider).getSourceSchema(); + } catch (IOException e) { + throw new RuntimeException(e); + } + } + + /** + * Pretty much copy-paste from the {@link AbstractKafkaAvroDeserializer} except line 87: + * DatumReader reader = new GenericDatumReader(schema, sourceSchema); + * <p> + * We need to inject reader schema during deserialization or later stages of the pipeline break. + * + * @param includeSchemaAndVersion + * @param topic + * @param isKey + * @param payload + * @param readerSchema + * @return + * @throws SerializationException + */ + @Override + protected Object deserialize( + boolean includeSchemaAndVersion, + String topic, + Boolean isKey, + byte[] payload, + Schema readerSchema) + throws SerializationException { + // Even if the caller requests schema & version, if the payload is null we cannot include it. + // The caller must handle + // this case. + if (payload == null) { + return null; + } + int id = -1; + try { + ByteBuffer buffer = getByteBuffer(payload); + id = buffer.getInt(); + Schema schema = schemaRegistry.getByID(id); + + int length = buffer.limit() - 1 - idSize; + final Object result; + if (schema.getType().equals(Schema.Type.BYTES)) { + byte[] bytes = new byte[length]; + buffer.get(bytes, 0, length); + result = bytes; + } else { + int start = buffer.position() + buffer.arrayOffset(); + DatumReader reader = new GenericDatumReader(schema, sourceSchema); Review comment: one more clarification @vburenin. Is this approach (passing sourceSchema instead of reader schema) is going to be useful for everyone(kakfa source users), even if they are not interested in meta fields to assist in schema evolution? If yes, wondering if we should make this customer deserializer as default kafka deserializer for hudi going forward? Can you throw some light 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
