tzulitai commented on a change in pull request #6711: [FLINK-9377] [core, state backends] Remove serializers from checkpoints URL: https://github.com/apache/flink/pull/6711#discussion_r223269252
########## File path: flink-core/src/main/java/org/apache/flink/api/common/typeutils/TypeSerializerConfigSnapshotSerializationUtil.java ########## @@ -0,0 +1,172 @@ +/* + * 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.api.common.typeutils; + +import org.apache.flink.core.io.VersionedIOReadableWritable; +import org.apache.flink.core.memory.DataInputView; +import org.apache.flink.core.memory.DataOutputView; +import org.apache.flink.util.InstantiationUtil; +import org.apache.flink.util.Preconditions; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.List; + +/** + * Utility methods for serialization of {@link TypeSerializerConfigSnapshot}. + */ +public class TypeSerializerConfigSnapshotSerializationUtil { + + /** + * Writes a {@link TypeSerializerConfigSnapshot} to the provided data output view. + * + * <p>It is written with a format that can be later read again using + * {@link #readSerializerConfigSnapshot(DataInputView, ClassLoader)}. + * + * @param out the data output view + * @param serializerConfigSnapshot the serializer configuration snapshot to write + * + * @throws IOException + */ + public static <T> void writeSerializerConfigSnapshot( + DataOutputView out, + TypeSerializerConfigSnapshot<T> serializerConfigSnapshot, + TypeSerializer<T> serializer) throws IOException { + + new TypeSerializerConfigSnapshotSerializationProxy<>(serializerConfigSnapshot, serializer).write(out); + } + + /** + * Reads from a data input view a {@link TypeSerializerConfigSnapshot} that was previously + * written using {@link TypeSerializerConfigSnapshotSerializationUtil#writeSerializerConfigSnapshot(DataOutputView, TypeSerializerConfigSnapshot, TypeSerializer)}. + * + * @param in the data input view + * @param userCodeClassLoader the user code class loader to use + * + * @return the read serializer configuration snapshot + * + * @throws IOException + */ + public static TypeSerializerConfigSnapshot readSerializerConfigSnapshot( + DataInputView in, + ClassLoader userCodeClassLoader) throws IOException { + + final TypeSerializerConfigSnapshotSerializationProxy proxy = new TypeSerializerConfigSnapshotSerializationProxy(userCodeClassLoader); + proxy.read(in); + + return proxy.getSerializerConfigSnapshot(); + } + + /** + * Reads from a data input view multiple {@link TypeSerializerConfigSnapshot}s that was previously + * written using {@link TypeSerializerConfigSnapshotSerializationUtil#writeSerializerConfigSnapshot(DataOutputView, TypeSerializerConfigSnapshot, TypeSerializer)}. + * + * @param in the data input view + * @param userCodeClassLoader the user code class loader to use + * + * @return the read serializer configuration snapshots + * + * @throws IOException + */ + public static List<TypeSerializerConfigSnapshot<?>> readSerializerConfigSnapshots( + DataInputView in, + ClassLoader userCodeClassLoader) throws IOException { + + int numFields = in.readInt(); + final List<TypeSerializerConfigSnapshot<?>> serializerConfigSnapshots = new ArrayList<>(numFields); + + TypeSerializerConfigSnapshotSerializationProxy proxy; + for (int i = 0; i < numFields; i++) { + proxy = new TypeSerializerConfigSnapshotSerializationProxy(userCodeClassLoader); + proxy.read(in); + serializerConfigSnapshots.add(proxy.getSerializerConfigSnapshot()); + } + + return serializerConfigSnapshots; + } + + /** + * Utility serialization proxy for a {@link TypeSerializerConfigSnapshot}. + */ + static final class TypeSerializerConfigSnapshotSerializationProxy<T> extends VersionedIOReadableWritable { + + private static final int VERSION = 1; + + private ClassLoader userCodeClassLoader; + private TypeSerializerConfigSnapshot<T> serializerConfigSnapshot; + private TypeSerializer<T> serializer; + + TypeSerializerConfigSnapshotSerializationProxy(ClassLoader userCodeClassLoader) { + this.userCodeClassLoader = Preconditions.checkNotNull(userCodeClassLoader); + } + + TypeSerializerConfigSnapshotSerializationProxy( + TypeSerializerConfigSnapshot<T> serializerConfigSnapshot, + TypeSerializer<T> serializer) { + this.serializerConfigSnapshot = Preconditions.checkNotNull(serializerConfigSnapshot); + this.serializer = Preconditions.checkNotNull(serializer); + } + + @Override + public void write(DataOutputView out) throws IOException { + super.write(out); + + // config snapshot class, so that we can re-instantiate the + // correct type of config snapshot instance when deserializing + out.writeUTF(serializerConfigSnapshot.getClass().getName()); + + // TODO this is a temporary workaround until all serializer config snapshot classes in Flink + // TODO have properly implemented the restore serializer factory methods + serializerConfigSnapshot.setSerializer(serializer); + + // the actual configuration parameters + serializerConfigSnapshot.write(out); + } + + @SuppressWarnings("unchecked") + @Override + public void read(DataInputView in) throws IOException { + super.read(in); + + String serializerConfigClassname = in.readUTF(); + Class<? extends TypeSerializerConfigSnapshot> serializerConfigSnapshotClass; + try { + serializerConfigSnapshotClass = (Class<? extends TypeSerializerConfigSnapshot>) + Class.forName(serializerConfigClassname, true, userCodeClassLoader); + } catch (ClassNotFoundException e) { + throw new IOException( + "Could not find requested TypeSerializerConfigSnapshot class " + + serializerConfigClassname + " in classpath.", e); + } + + serializerConfigSnapshot = InstantiationUtil.instantiate(serializerConfigSnapshotClass); + serializerConfigSnapshot.setUserCodeClassLoader(userCodeClassLoader); Review comment: Actually, this has been addressed as part of introducing the new `TypeSerializerSnapshot` interface. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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