Github user abhishekagarwal87 commented on a diff in the pull request:
https://github.com/apache/storm/pull/1052#discussion_r51082690
--- Diff:
external/storm-hdfs/src/main/java/org/apache/storm/hdfs/common/AvroGenericSerializer.java
---
@@ -0,0 +1,70 @@
+/**
+ * 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.storm.hdfs.common;
+
+import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.io.Input;
+import com.esotericsoftware.kryo.io.Output;
+import org.apache.avro.Schema;
+import org.apache.avro.generic.GenericContainer;
+import org.apache.avro.generic.GenericDatumReader;
+import org.apache.avro.generic.GenericDatumWriter;
+import org.apache.avro.io.BinaryEncoder;
+import org.apache.avro.io.Decoder;
+import org.apache.avro.io.DecoderFactory;
+import org.apache.avro.io.EncoderFactory;
+
+import java.io.IOException;
+
+//Generously adapted from:
+//https://github.com/kijiproject/kiji-express/blob/master/kiji-express/src/main/scala/org/kiji/express/flow/framework/serialization/AvroSerializer.scala
+//Which has as an ASL2.0 license
+public class AvroGenericSerializer extends Serializer<GenericContainer> {
+ @Override
+ public void write(Kryo kryo, Output output, GenericContainer record) {
+ output.writeString(record.getSchema().toString());
+ GenericDatumWriter<GenericContainer> writer = new
GenericDatumWriter<>(record.getSchema());
+
+ BinaryEncoder encoder = EncoderFactory
+ .get()
+ .directBinaryEncoder(output, null);
+ try {
+ writer.write(record, encoder);
+ } catch (IOException e) {
+ throw new RuntimeException(e);
+ }
+ }
+
+ @Override
+ public GenericContainer read(Kryo kryo, Input input,
Class<GenericContainer> aClass) {
+ Schema theSchema = new Schema.Parser().parse(input.readString());
--- End diff --
The approach sounds right. Though I will suggest not to use the above
version of schema registry as default one as it is costly.
`
class GenericAvroSchemaRegistry2 implements AvroSchemaRegistry {
private BiMap<String,Schema> schemaMap; //This is populated while
building the topology. It should be serializable.
public String getKey(Schema schema) {
return schemaMap.get(schema);
}
public Schema getSchema(String key) {
return schemaMap.get(key);
}
`
Multiple implementations of the registry can be shipped. However, default
one should be safest option to use.
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