org.apache.kafka.streams.kstream.internals.KStreamJoinWindow Maven / Gradle / Ivy
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* 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
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* distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.kafka.streams.kstream.internals;
import org.apache.kafka.streams.processor.api.ContextualProcessor;
import org.apache.kafka.streams.processor.api.Processor;
import org.apache.kafka.streams.processor.api.ProcessorContext;
import org.apache.kafka.streams.processor.api.ProcessorSupplier;
import org.apache.kafka.streams.processor.api.Record;
import org.apache.kafka.streams.state.WindowStore;
class KStreamJoinWindow implements ProcessorSupplier {
private final String windowName;
KStreamJoinWindow(final String windowName) {
this.windowName = windowName;
}
@Override
public Processor get() {
return new KStreamJoinWindowProcessor();
}
private class KStreamJoinWindowProcessor extends ContextualProcessor {
private WindowStore window;
@Override
public void init(final ProcessorContext context) {
super.init(context);
window = context.getStateStore(windowName);
}
@Override
public void process(final Record record) {
// if the key is null, we do not need to put the record into window store
// since it will never be considered for join operations
if (record.key() != null) {
context().forward(record);
// Every record basically starts a new window. We're using a window store mostly for the retention.
window.put(record.key(), record.value(), record.timestamp());
}
}
}
}