flink-core/src/main/java/org/apache/flink/api/common/typeutils/base/MapSerializerSnapshot.java

/*
 * 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.api.common.typeutils.CompositeTypeSerializerSnapshot;
import org.apache.flink.api.common.typeutils.TypeSerializer;

import java.util.Map;

/**
 * Snapshot class for the {@link MapSerializer}.
 */
public class MapSerializerSnapshot<K, V> extends CompositeTypeSerializerSnapshot<Map<K, V>, MapSerializer> {

	private static final int CURRENT_VERSION = 1;

	/**
	 * Constructor for read instantiation.
	 */
	public MapSerializerSnapshot() {
		super(MapSerializer.class);
	}

	/**
	 * Constructor to create the snapshot for writing.
	 */
	public MapSerializerSnapshot(MapSerializer<K, V> mapSerializer) {
		super(mapSerializer);
	}

	@Override
	public int getCurrentOuterSnapshotVersion() {
		return CURRENT_VERSION;
	}

	@Override
	protected MapSerializer createOuterSerializerWithNestedSerializers(TypeSerializer<?>[] nestedSerializers) {
		@SuppressWarnings("unchecked")
		TypeSerializer<K> keySerializer = (TypeSerializer<K>) nestedSerializers[0];

		@SuppressWarnings("unchecked")
		TypeSerializer<V> valueSerializer = (TypeSerializer<V>) nestedSerializers[1];

		return new MapSerializer<>(keySerializer, valueSerializer);
	}

	@Override
	protected TypeSerializer<?>[] getNestedSerializers(MapSerializer outerSerializer) {
		return new TypeSerializer<?>[] { outerSerializer.getKeySerializer(), outerSerializer.getValueSerializer() };
	}
}