org.apache.flink.runtime.state.StateUtils Maven / Gradle / Ivy
/*
* 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.runtime.state;
import org.apache.flink.runtime.jobgraph.tasks.StatefulTask;
/**
* A collection of utility methods for dealing with operator state.
*/
public class StateUtils {
/**
* Utility method to define a common generic bound to be used for setting a
* generic state handle on a generic state carrier.
*
* This has no impact on runtime, since internally, it performs unchecked
* casts. The purpose is merely to allow the use of generic interfaces
* without resorting to raw types, by giving the compiler a common type
* bound.
*
* @param op
* The state carrier operator.
* @param state
* The state handle.
* @param
* Type bound for the
*/
public static > void setOperatorState(StatefulTask op, StateHandle state)
throws Exception {
@SuppressWarnings("unchecked")
StatefulTask typedOp = (StatefulTask) op;
@SuppressWarnings("unchecked")
T typedHandle = (T) state;
typedOp.setInitialState(typedHandle);
}
// ------------------------------------------------------------------------
/** Do not instantiate */
private StateUtils() {}
}