org.apache.flink.runtime.state.ManagedInitializationContext 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
* 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,
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* See the License for the specific language governing permissions and
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*/
package org.apache.flink.runtime.state;
import org.apache.flink.api.common.state.KeyedStateStore;
import org.apache.flink.api.common.state.OperatorStateStore;
/**
* This interface provides a context in which operators can initialize by registering to managed
* state (i.e. state that is managed by state backends).
*
* Operator state is available to all operators, while keyed state is only available for
* operators after keyBy.
*
*
For the purpose of initialization, the context signals if the state is empty (new operator) or
* was restored from a previous execution of this operator.
*/
public interface ManagedInitializationContext {
/**
* Returns true, if state was restored from the snapshot of a previous execution. This returns
* always false for stateless tasks.
*/
boolean isRestored();
/** Returns an interface that allows for registering operator state with the backend. */
OperatorStateStore getOperatorStateStore();
/** Returns an interface that allows for registering keyed state with the backend. */
KeyedStateStore getKeyedStateStore();
}