igalshilman commented on a change in pull request #7759: [FLINK-11485][FLINK-10897] POJO state schema evolution / migrate PojoSerializer to use new compatibility APIs URL: https://github.com/apache/flink/pull/7759#discussion_r258824773
########## File path: flink-core/src/main/java/org/apache/flink/api/java/typeutils/runtime/PojoSerializerSnapshotData.java ########## @@ -0,0 +1,308 @@ +/* + * 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.java.typeutils.runtime; + +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.api.common.typeutils.TypeSerializerUtils; +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.LinkedOptionalMap; +import org.apache.flink.util.function.BiConsumerWithException; +import org.apache.flink.util.function.BiFunctionWithException; +import org.apache.flink.util.function.FunctionWithException; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.lang.reflect.Field; +import java.util.HashMap; +import java.util.LinkedHashMap; +import java.util.Map; + +import static org.apache.flink.util.LinkedOptionalMap.optionalMapOf; +import static org.apache.flink.util.Preconditions.checkNotNull; + +/** + * This class holds the snapshot content for the {@link PojoSerializer}. + * + * <h2>Serialization Format</hr> + * + * <p>The serialization format defined by this class is as follows: + * + * <pre>{@code + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | POJO class name | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | number of fields | (field name, field serializer snapshot) | + * | | pairs | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | number of | (registered subclass name, subclass serializer snapshot) | + * | registered subclasses | pairs | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | number of | (non-registered subclass name, subclass serializer snapshot) | + * | non-registered subclasses | pairs | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * }</pre> + */ +@Internal +final class PojoSerializerSnapshotData<T> { + + private static final Logger LOG = LoggerFactory.getLogger(PojoSerializerSnapshotData.class); + + // --------------------------------------------------------------------------------------------- + // Factory methods + // --------------------------------------------------------------------------------------------- + + /** + * Creates a {@link PojoSerializerSnapshotData} from configuration of a {@link PojoSerializer}. + * + * <p>This factory method is meant to be used in regular write paths, i.e. when taking a snapshot + * of the {@link PojoSerializer}. All POJO fields, registered subclass classes, and non-registered + * subclass classes are all present. + */ + static <T> PojoSerializerSnapshotData<T> createFrom( + Class<T> pojoClass, + LinkedHashMap<Field, TypeSerializer<?>> fieldSerializers, + LinkedHashMap<Class<?>, TypeSerializer<?>> registeredSubclassSerializers, + Map<Class<?>, TypeSerializer<?>> nonRegisteredSubclassSerializers) { + + LinkedHashMap<Field, TypeSerializerSnapshot<?>> fieldSerializerSnapshots = new LinkedHashMap<>(fieldSerializers.size()); + fieldSerializers.forEach((k, v) -> fieldSerializerSnapshots.put(k, TypeSerializerUtils.snapshotBackwardsCompatible(v))); + + LinkedHashMap<Class<?>, TypeSerializerSnapshot<?>> registeredSubclassSerializerSnapshots = new LinkedHashMap<>(registeredSubclassSerializers.size()); + registeredSubclassSerializers.forEach((k, v) -> registeredSubclassSerializerSnapshots.put(k, TypeSerializerUtils.snapshotBackwardsCompatible(v))); + + Map<Class<?>, TypeSerializerSnapshot<?>> nonRegisteredSubclassSerializerSnapshots = new HashMap<>(nonRegisteredSubclassSerializers.size()); + nonRegisteredSubclassSerializers.forEach((k, v) -> nonRegisteredSubclassSerializerSnapshots.put(k, TypeSerializerUtils.snapshotBackwardsCompatible(v))); + + return new PojoSerializerSnapshotData<>( + pojoClass, + optionalMapOf(fieldSerializerSnapshots, Field::getName), + optionalMapOf(registeredSubclassSerializerSnapshots, Class::getName), + optionalMapOf(nonRegisteredSubclassSerializerSnapshots, Class::getName)); + } + + /** + * Creates a {@link PojoSerializerSnapshotData} from serialized data stream. + * + * <p>This factory method is meant to be used in regular read paths, i.e. when reading back a snapshot + * of the {@link PojoSerializer}. POJO fields, registered subclass classes, and non-registered subclass + * classes may no longer be present anymore. + */ + static <T> PojoSerializerSnapshotData<T> createFrom(DataInputView in, ClassLoader userCodeClassLoader) throws IOException { + return PojoSerializerSnapshotData.readSnapshotData(in, userCodeClassLoader); + } + + /** + * Creates a {@link PojoSerializerSnapshotData} from existing snapshotted configuration of a {@link PojoSerializer}. + * + * <p>This factory method is meant to be used for backwards compatible read paths. + */ + static <T> PojoSerializerSnapshotData<T> createFrom( + Class<T> pojoClass, + LinkedHashMap<Field, TypeSerializerSnapshot<?>> existingFieldSerializerSnapshots, + LinkedHashMap<Class<?>, TypeSerializerSnapshot<?>> existingRegisteredSubclassSerializerSnapshots, + LinkedHashMap<Class<?>, TypeSerializerSnapshot<?>> existingNonRegisteredSubclassSerializerSnapshots) { + + return new PojoSerializerSnapshotData<>( + pojoClass, + optionalMapOf(existingFieldSerializerSnapshots, Field::getName), + optionalMapOf(existingRegisteredSubclassSerializerSnapshots, Class::getName), + optionalMapOf(existingNonRegisteredSubclassSerializerSnapshots, Class::getName)); + } + + private Class<T> pojoClass; + private LinkedOptionalMap<Field, TypeSerializerSnapshot<?>> fieldSerializerSnapshots; + private LinkedOptionalMap<Class<?>, TypeSerializerSnapshot<?>> registeredSubclassSerializerSnapshots; + private LinkedOptionalMap<Class<?>, TypeSerializerSnapshot<?>> nonRegisteredSubclassSerializerSnapshots; + + private PojoSerializerSnapshotData( + Class<T> typeClass, + LinkedOptionalMap<Field, TypeSerializerSnapshot<?>> fieldSerializerSnapshots, + LinkedOptionalMap<Class<?>, TypeSerializerSnapshot<?>> registeredSubclassSerializerSnapshots, + LinkedOptionalMap<Class<?>, TypeSerializerSnapshot<?>> nonRegisteredSubclassSerializerSnapshots) { + + this.pojoClass = checkNotNull(typeClass); + this.fieldSerializerSnapshots = checkNotNull(fieldSerializerSnapshots); + this.registeredSubclassSerializerSnapshots = checkNotNull(registeredSubclassSerializerSnapshots); + this.nonRegisteredSubclassSerializerSnapshots = checkNotNull(nonRegisteredSubclassSerializerSnapshots); + } + + // --------------------------------------------------------------------------------------------- + // Snapshot data read / write methods + // --------------------------------------------------------------------------------------------- + + void writeSnapshotData(DataOutputView out) throws IOException { + out.writeUTF(pojoClass.getName()); + writeOptionalMap(out, fieldSerializerSnapshots, PojoFieldUtils::writeField, TypeSerializerSnapshot::writeVersionedSnapshot); + writeOptionalMap(out, registeredSubclassSerializerSnapshots, NoOpWriter.noopWriter(), TypeSerializerSnapshot::writeVersionedSnapshot); + writeOptionalMap(out, nonRegisteredSubclassSerializerSnapshots, NoOpWriter.noopWriter(), TypeSerializerSnapshot::writeVersionedSnapshot); + } + + private static <T> PojoSerializerSnapshotData<T> readSnapshotData(DataInputView in, ClassLoader userCodeClassLoader) throws IOException { + Class<T> pojoClass = InstantiationUtil.resolveClassByName(in, userCodeClassLoader); + + LinkedOptionalMap<Field, TypeSerializerSnapshot<?>> fieldSerializerSnapshots = readOptionalMap( + in, + fieldReader(userCodeClassLoader), + snapshotReader(userCodeClassLoader)); + LinkedOptionalMap<Class<?>, TypeSerializerSnapshot<?>> registeredSubclassSerializerSnapshots = readOptionalMap( + in, + classReader(userCodeClassLoader), + snapshotReader(userCodeClassLoader)); + LinkedOptionalMap<Class<?>, TypeSerializerSnapshot<?>> nonRegisteredSubclassSerializerSnapshots = readOptionalMap( + in, + classReader(userCodeClassLoader), + snapshotReader(userCodeClassLoader)); + + return new PojoSerializerSnapshotData<>(pojoClass, fieldSerializerSnapshots, registeredSubclassSerializerSnapshots, nonRegisteredSubclassSerializerSnapshots); + } + + // --------------------------------------------------------------------------------------------- + // Snapshot data accessors + // --------------------------------------------------------------------------------------------- + + Class<T> getPojoClass() { + return pojoClass; + } + + LinkedOptionalMap<Field, TypeSerializerSnapshot<?>> getFieldSerializerSnapshots() { + return fieldSerializerSnapshots; + } + + LinkedOptionalMap<Class<?>, TypeSerializerSnapshot<?>> getRegisteredSubclassSerializerSnapshots() { + return registeredSubclassSerializerSnapshots; + } + + LinkedOptionalMap<Class<?>, TypeSerializerSnapshot<?>> getNonRegisteredSubclassSerializerSnapshots() { + return nonRegisteredSubclassSerializerSnapshots; + } + + // --------------------------------------------------------------------------------------------- + // Utilities + // --------------------------------------------------------------------------------------------- + + private static <K, V> void writeOptionalMap( + DataOutputView out, + LinkedOptionalMap<K, V> map, + BiConsumerWithException<DataOutputView, K, IOException> keyWriter, + BiConsumerWithException<DataOutputView, V, IOException> valueWriter) throws IOException { + + out.writeInt(map.size()); + map.forEach(((keyName, key, value) -> { + out.writeUTF(keyName); + if (key == null) { + out.writeBoolean(false); + } Review comment: nit: I think the formatting here are a bit funky ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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