aljoscha commented on a change in pull request #13825: URL: https://github.com/apache/flink/pull/13825#discussion_r513411521
########## File path: flink-core/src/main/java/org/apache/flink/core/io/SimpleVersionedSerializerTypeSerializerProxy.java ########## @@ -0,0 +1,163 @@ +/* + * 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.flink.core.io; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.api.common.typeutils.TypeSerializer; +import org.apache.flink.api.common.typeutils.TypeSerializerSnapshot; +import org.apache.flink.core.memory.DataInputView; +import org.apache.flink.core.memory.DataOutputView; +import org.apache.flink.util.InstantiationUtil; + +import java.io.IOException; +import java.io.Serializable; +import java.util.function.Supplier; + +/** + * A {@link TypeSerializer} that delegates to an underlying {@link SimpleVersionedSerializer}. + */ +@Internal +public class SimpleVersionedSerializerTypeSerializerProxy<T> extends TypeSerializer<T> implements Serializable { + + private final SerializableSupplier<SimpleVersionedSerializer<T>> serializerSupplier; + private transient SimpleVersionedSerializer<T> cachedSerializer; + + public SimpleVersionedSerializerTypeSerializerProxy( + SerializableSupplier<SimpleVersionedSerializer<T>> serializerSupplier) { + this.serializerSupplier = serializerSupplier; + } + + @Override + public boolean isImmutableType() { + return false; + } + + @Override + public TypeSerializer<T> duplicate() { + final byte[] serializedSerializer; + try { + serializedSerializer = InstantiationUtil.serializeObject(serializerSupplier); + } catch (IOException e) { + throw new RuntimeException("Could not serialize SimpleVersionedSerializer.", e); + } + try { + return new SimpleVersionedSerializerTypeSerializerProxy<>( + InstantiationUtil.deserializeObject( + serializedSerializer, + serializerSupplier.getClass().getClassLoader())); + } catch (ClassNotFoundException | IOException e) { + throw new RuntimeException("Could not duplicate SimpleVersionedSerializer.", e); + } + } + + @Override + public T createInstance() { + return null; + } + + @Override + public T copy(T from) { + SimpleVersionedSerializer<T> serializer = getSerializer(); + try { + byte[] serializedFrom = serializer.serialize(from); + return serializer.deserialize( + serializer.getVersion(), + serializedFrom); + } catch (IOException e) { + throw new RuntimeException("Could not copy element.", e); + } + } + + @Override + public T copy(T from, T reuse) { + // the reuse is optional, we can just ignore it + return copy(from); + } + + @Override + public int getLength() { + return -1; + } + + @Override + public void serialize(T record, DataOutputView target) throws IOException { + SimpleVersionedSerializer<T> serializer = getSerializer(); + target.writeInt(serializer.getVersion()); Review comment: Yes, this whole things a pickle. I don't want to add a snapshot because that's complicated and would require me to serialize the supplier, which we shouldn't do. I'm fine with removing the version but I think leaving it in would make the code a tiny bit more future proof. ---------------------------------------------------------------- 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
