org.apache.kafka.connect.storage.MemoryOffsetBackingStore 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.kafka.connect.storage;
import org.apache.kafka.connect.errors.ConnectException;
import org.apache.kafka.connect.runtime.WorkerConfig;
import org.apache.kafka.connect.util.Callback;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.nio.ByteBuffer;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
/**
* Implementation of OffsetBackingStore that doesn't actually persist any data. To ensure this
* behaves similarly to a real backing store, operations are executed asynchronously on a
* background thread.
*/
public class MemoryOffsetBackingStore implements OffsetBackingStore {
private static final Logger log = LoggerFactory.getLogger(MemoryOffsetBackingStore.class);
protected Map data = new HashMap<>();
protected ExecutorService executor;
public MemoryOffsetBackingStore() {
}
@Override
public void configure(WorkerConfig config) {
}
@Override
public void start() {
executor = Executors.newSingleThreadExecutor();
}
@Override
public void stop() {
if (executor != null) {
executor.shutdown();
// Best effort wait for any get() and set() tasks (and caller's callbacks) to complete.
try {
executor.awaitTermination(30, TimeUnit.SECONDS);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
if (!executor.shutdownNow().isEmpty()) {
throw new ConnectException("Failed to stop MemoryOffsetBackingStore. Exiting without cleanly " +
"shutting down pending tasks and/or callbacks.");
}
executor = null;
}
}
@Override
public Future> get(
final Collection keys,
final Callback> callback) {
return executor.submit(new Callable>() {
@Override
public Map call() throws Exception {
Map result = new HashMap<>();
for (ByteBuffer key : keys) {
result.put(key, data.get(key));
}
if (callback != null)
callback.onCompletion(null, result);
return result;
}
});
}
@Override
public Future set(final Map values,
final Callback callback) {
return executor.submit(new Callable() {
@Override
public Void call() throws Exception {
for (Map.Entry entry : values.entrySet()) {
data.put(entry.getKey(), entry.getValue());
}
save();
if (callback != null)
callback.onCompletion(null, null);
return null;
}
});
}
// Hook to allow subclasses to persist data
protected void save() {
}
}