/*
* 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.kafka.streams.kstream.internals;
import org.apache.kafka.streams.processor.AbstractProcessor;
import org.apache.kafka.streams.processor.Processor;
import org.apache.kafka.streams.processor.ProcessorContext;
import org.apache.kafka.streams.state.KeyValueStore;
class KTableKTableJoinMerger<K, V> implements KTableProcessorSupplier<K, V, V> {
private final KTableImpl<K, ?, V> parent1;
private final KTableImpl<K, ?, V> parent2;
private final String queryableName;
private boolean sendOldValues = false;
public KTableKTableJoinMerger(final KTableImpl<K, ?, V> parent1,
final KTableImpl<K, ?, V> parent2,
final String queryableName) {
this.parent1 = parent1;
this.parent2 = parent2;
this.queryableName = queryableName;
}
@Override
public Processor<K, Change<V>> get() {
return new KTableKTableJoinMergeProcessor<>();
}
@Override
public KTableValueGetterSupplier<K, V> view() {
return parent1.valueGetterSupplier();
}
@Override
public void enableSendingOldValues() {
parent1.enableSendingOldValues();
parent2.enableSendingOldValues();
sendOldValues = true;
}
private class KTableKTableJoinMergeProcessor<K, V>
extends AbstractProcessor<K, Change<V>> {
private KeyValueStore<K, V> store;
private TupleForwarder<K, V> tupleForwarder;
@SuppressWarnings("unchecked")
@Override
public void init(ProcessorContext context) {
super.init(context);
if (queryableName != null) {
store = (KeyValueStore<K, V>) context.getStateStore(queryableName);
tupleForwarder = new TupleForwarder<>(store, context,
new ForwardingCacheFlushListener<K, V>(context, sendOldValues),
sendOldValues);
}
}
@Override
public void process(K key, Change<V> value) {
if (queryableName != null) {
store.put(key, value.newValue);
tupleForwarder.maybeForward(key, value.newValue, value.oldValue);
} else {
context().forward(key, value);
}
}
}
}