/*
* 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.kstream.KeyValueMapper;
import org.apache.kafka.streams.kstream.ValueJoiner;
import org.apache.kafka.streams.processor.AbstractProcessor;
import org.apache.kafka.streams.processor.Processor;
import org.apache.kafka.streams.processor.ProcessorContext;
class KTableKTableJoin<K, R, V1, V2> extends KTableKTableAbstractJoin<K, R, V1, V2> {
private final KeyValueMapper<K, V1, K> keyValueMapper = new KeyValueMapper<K, V1, K>() {
@Override
public K apply(final K key, final V1 value) {
return key;
}
};
KTableKTableJoin(KTableImpl<K, ?, V1> table1, KTableImpl<K, ?, V2> table2, ValueJoiner<? super V1, ? super V2, ? extends R> joiner) {
super(table1, table2, joiner);
}
@Override
public Processor<K, Change<V1>> get() {
return new KTableKTableJoinProcessor(valueGetterSupplier2.get());
}
@Override
public KTableValueGetterSupplier<K, R> view() {
return new KTableKTableJoinValueGetterSupplier(valueGetterSupplier1, valueGetterSupplier2);
}
private class KTableKTableJoinValueGetterSupplier extends AbstractKTableKTableJoinValueGetterSupplier<K, R, V1, V2> {
public KTableKTableJoinValueGetterSupplier(KTableValueGetterSupplier<K, V1> valueGetterSupplier1, KTableValueGetterSupplier<K, V2> valueGetterSupplier2) {
super(valueGetterSupplier1, valueGetterSupplier2);
}
public KTableValueGetter<K, R> get() {
return new KTableKTableJoinValueGetter<>(valueGetterSupplier1.get(),
valueGetterSupplier2.get(),
joiner,
keyValueMapper);
}
}
private class KTableKTableJoinProcessor extends AbstractProcessor<K, Change<V1>> {
private final KTableValueGetter<K, V2> valueGetter;
public KTableKTableJoinProcessor(KTableValueGetter<K, V2> valueGetter) {
this.valueGetter = valueGetter;
}
@SuppressWarnings("unchecked")
@Override
public void init(ProcessorContext context) {
super.init(context);
valueGetter.init(context);
}
@Override
public void process(final K key, final Change<V1> change) {
// we do join iff keys are equal, thus, if key is null we cannot join and just ignore the record
if (key == null) {
return;
}
R newValue = null;
R oldValue = null;
final V2 value2 = valueGetter.get(key);
if (value2 == null) {
return;
}
if (change.newValue != null) {
newValue = joiner.apply(change.newValue, value2);
}
if (sendOldValues && change.oldValue != null) {
oldValue = joiner.apply(change.oldValue, value2);
}
context().forward(key, new Change<>(newValue, oldValue));
}
}
}