org.apache.flink.streaming.api.functions.query.AbstractQueryableStateOperator Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* 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.streaming.api.functions.query;
import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.state.State;
import org.apache.flink.api.common.state.StateDescriptor;
import org.apache.flink.streaming.api.operators.AbstractStreamOperator;
import org.apache.flink.streaming.api.operators.OneInputStreamOperator;
import org.apache.flink.util.Preconditions;
/**
* Internal operator handling queryable state instances (setup and update).
*
* @param State type
* @param Input type
*/
@Internal
abstract class AbstractQueryableStateOperator
extends AbstractStreamOperator implements OneInputStreamOperator {
private static final long serialVersionUID = 7842489558298787382L;
/** State descriptor for the queryable state instance. */
protected final StateDescriptor stateDescriptor;
/** Name under which the queryable state is registered. */
protected final String registrationName;
/**
* The state instance created on open. This is updated by the subclasses of this class, because
* the state update interface depends on the state type (e.g. AppendingState#add(IN) vs.
* ValueState#update(OUT)).
*/
protected transient S state;
public AbstractQueryableStateOperator(
String registrationName, StateDescriptor stateDescriptor) {
this.registrationName = Preconditions.checkNotNull(registrationName, "Registration name");
this.stateDescriptor = Preconditions.checkNotNull(stateDescriptor, "State descriptor");
if (stateDescriptor.isQueryable()) {
String name = stateDescriptor.getQueryableStateName();
if (!name.equals(registrationName)) {
throw new IllegalArgumentException(
"StateDescriptor already marked as "
+ "queryable with name '"
+ name
+ "', but created operator with name '"
+ registrationName
+ "'.");
} // else: all good, already registered with same name
} else {
stateDescriptor.setQueryable(registrationName);
}
}
@Override
public void open() throws Exception {
super.open();
state = getPartitionedState(stateDescriptor);
}
}