org.apache.flink.runtime.state.AsynchronousKvStateSnapshot 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.api.common.state.State;
import org.apache.flink.api.common.state.StateDescriptor;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import java.io.IOException;
/**
* {@link KvStateSnapshot} that asynchronously materializes the state that it represents. Instead
* of representing a materialized handle to state this would normally hold the (immutable) state
* internally and materializes it when {@link #materialize()} is called.
*
* @param The type of the key
* @param The type of the namespace
* @param The type of the {@link State}
* @param The type of the {@link StateDescriptor}
* @param The type of the backend that can restore the state from this snapshot.
*/
public abstract class AsynchronousKvStateSnapshot, Backend extends AbstractStateBackend> implements KvStateSnapshot {
private static final long serialVersionUID = 1L;
/**
* Materializes the state held by this {@code AsynchronousKvStateSnapshot}.
*/
public abstract KvStateSnapshot materialize() throws Exception;
@Override
public final KvState restoreState(
Backend stateBackend,
TypeSerializer keySerializer,
ClassLoader classLoader) throws Exception {
throw new RuntimeException("This should never be called and probably points to a bug.");
}
@Override
public long getStateSize() throws Exception {
throw new RuntimeException("This should never be called and probably points to a bug.");
}
@Override
public void close() throws IOException {
throw new RuntimeException("This should never be called and probably points to a bug.");
}
}