| /* |
| * 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.base; |
| |
| import org.apache.flink.annotation.Internal; |
| import org.apache.flink.api.common.typeutils.CompatibilityResult; |
| import org.apache.flink.api.common.typeutils.ParameterlessTypeSerializerConfig; |
| import org.apache.flink.api.common.typeutils.TypeSerializer; |
| import org.apache.flink.api.common.typeutils.TypeSerializerConfigSnapshot; |
| |
| @Internal |
| public abstract class TypeSerializerSingleton<T> extends TypeSerializer<T>{ |
| |
| private static final long serialVersionUID = 8766687317209282373L; |
| |
| // -------------------------------------------------------------------------------------------- |
| |
| @Override |
| public TypeSerializerSingleton<T> duplicate() { |
| return this; |
| } |
| |
| @Override |
| public int hashCode() { |
| return this.getClass().hashCode(); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (obj instanceof TypeSerializerSingleton) { |
| TypeSerializerSingleton<?> other = (TypeSerializerSingleton<?>) obj; |
| |
| return other.canEqual(this); |
| } else { |
| return false; |
| } |
| } |
| |
| @Override |
| public TypeSerializerConfigSnapshot snapshotConfiguration() { |
| // type serializer singletons should always be parameter-less |
| return new ParameterlessTypeSerializerConfig(getSerializationFormatIdentifier()); |
| } |
| |
| @Override |
| public CompatibilityResult<T> ensureCompatibility(TypeSerializerConfigSnapshot configSnapshot) { |
| if (configSnapshot instanceof ParameterlessTypeSerializerConfig |
| && isCompatibleSerializationFormatIdentifier( |
| ((ParameterlessTypeSerializerConfig) configSnapshot).getSerializationFormatIdentifier())) { |
| |
| return CompatibilityResult.compatible(); |
| } else { |
| return CompatibilityResult.requiresMigration(); |
| } |
| } |
| |
| /** |
| * Subclasses can override this if they know that they are also compatible with identifiers of other formats. |
| */ |
| protected boolean isCompatibleSerializationFormatIdentifier(String identifier) { |
| return identifier.equals(getSerializationFormatIdentifier()); |
| } |
| |
| private String getSerializationFormatIdentifier() { |
| return getClass().getCanonicalName(); |
| } |
| } |