org.apache.flink.runtime.state.context.ContextValueState 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,
* 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.context;
import org.apache.flink.api.common.state.ValueState;
import org.apache.flink.api.common.state.ValueStateDescriptor;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.runtime.state.VoidNamespace;
import org.apache.flink.runtime.state.internal.InternalValueState;
import org.apache.flink.runtime.state.keyed.KeyedState;
import org.apache.flink.runtime.state.keyed.KeyedValueState;
import org.apache.flink.runtime.state.heap.KeyContextImpl;
import org.apache.flink.util.Preconditions;
import java.io.IOException;
/**
* An implementation of {@link ValueState} which is backed by a
* {@link KeyedValueState}. The values of the states depend on the current key
* of the keyContext. That is, when the current key of the keyContext changes, the
* values accessed will be changed as well.
*
* @param The type of the values in the state.
*/
public class ContextValueState implements ContextKeyedState, InternalValueState {
/** The keyContext to which the state belongs. */
private final KeyContextImpl keyContext;
/** The keyed state backing the state. */
private final KeyedValueState keyedState;
/** The descriptor of the state. */
private final ValueStateDescriptor stateDescriptor;
public ContextValueState(
final KeyContextImpl operator,
final KeyedValueState keyedState,
final ValueStateDescriptor stateDescriptor
) {
Preconditions.checkNotNull(operator);
Preconditions.checkNotNull(keyedState);
Preconditions.checkNotNull(stateDescriptor);
this.keyContext = operator;
this.keyedState = keyedState;
this.stateDescriptor = stateDescriptor;
}
@Override
public V value() throws IOException {
Object key = keyContext.getCurrentKey();
Preconditions.checkNotNull(key, "No key set. This method should not be called outside of a keyed context.");
V value = keyedState.get(key);
return value == null ? stateDescriptor.getDefaultValue() : value;
}
@Override
public void update(V value) throws IOException {
if (value == null) {
clear();
} else {
keyedState.put(keyContext.getCurrentKey(), value);
}
}
@Override
public void clear() {
keyedState.remove(keyContext.getCurrentKey());
}
@Override
public KeyedState getKeyedState() {
return keyedState;
}
@Override
public TypeSerializer getKeySerializer() {
return keyContext.getKeySerializer();
}
@Override
public TypeSerializer getValueSerializer() {
return keyedState.getDescriptor().getValueSerializer();
}
@Override
public byte[] getSerializedValue(
byte[] serializedKeyAndNamespace,
TypeSerializer safeKeySerializer,
TypeSerializer safeNamespaceSerializer,
TypeSerializer safeValueSerializer) throws Exception {
return keyedState.getSerializedValue(serializedKeyAndNamespace, safeKeySerializer, safeValueSerializer);
}
}