org.apache.flink.runtime.state.Snapshotable Maven / Gradle / Ivy
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* 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
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.state;
import org.apache.flink.annotation.Internal;
import javax.annotation.Nullable;
/**
* Interface for operators that can perform snapshots of their state.
*
* @param Generic type of the state object that is created as handle to snapshots.
* @param Generic type of the state object that used in restore.
*/
@Internal
public interface Snapshotable extends SnapshotStrategy {
/**
* Restores state that was previously snapshotted from the provided parameters. Typically the parameters are state
* handles from which the old state is read.
*
* @param state the old state to restore.
*/
void restore(@Nullable R state) throws Exception;
}