/*
* Copyright © 2014 Cask Data, Inc.
*
* Licensed 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 co.cask.cdap.data.runtime;
import co.cask.cdap.api.flow.flowlet.StreamEvent;
import co.cask.cdap.common.queue.QueueName;
import co.cask.cdap.common.stream.StreamEventCodec;
import co.cask.cdap.data.file.FileWriter;
import co.cask.cdap.data.stream.StreamFileWriterFactory;
import co.cask.cdap.data2.queue.QueueClientFactory;
import co.cask.cdap.data2.queue.QueueEntry;
import co.cask.cdap.data2.queue.QueueProducer;
import co.cask.cdap.data2.transaction.stream.StreamConfig;
import co.cask.tephra.TransactionAware;
import co.cask.tephra.TransactionExecutor;
import co.cask.tephra.TransactionExecutorFactory;
import co.cask.tephra.TransactionFailureException;
import com.google.common.collect.Lists;
import com.google.inject.Inject;
import java.io.Closeable;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.util.List;
/**
* A Mock {@link StreamFileWriterFactory} that actually doesn't write to file, but to in memory queue instead.
*/
final class InMemoryStreamFileWriterFactory implements StreamFileWriterFactory {
private static final StreamEventCodec STREAM_EVENT_CODEC = new StreamEventCodec();
private final QueueClientFactory queueClientFactory;
private final TransactionExecutorFactory executorFactory;
@Inject
InMemoryStreamFileWriterFactory(QueueClientFactory queueClientFactory, TransactionExecutorFactory executorFactory) {
this.queueClientFactory = queueClientFactory;
this.executorFactory = executorFactory;
}
@Override
public FileWriter<StreamEvent> create(StreamConfig config, int generation) throws IOException {
final QueueProducer producer = queueClientFactory.createProducer(QueueName.fromStream(config.getName()));
final List<TransactionAware> txAwares = Lists.newArrayList();
if (producer instanceof TransactionAware) {
txAwares.add((TransactionAware) producer);
}
final TransactionExecutor txExecutor = executorFactory.createExecutor(txAwares);
// Adapt the FileWriter interface into Queue2Producer
return new FileWriter<StreamEvent>() {
private final List<StreamEvent> events = Lists.newArrayList();
@Override
public void append(StreamEvent event) throws IOException {
events.add(event);
}
@Override
public void close() throws IOException {
if (producer instanceof Closeable) {
((Closeable) producer).close();
}
}
@Override
public void flush() throws IOException {
try {
txExecutor.execute(new TransactionExecutor.Subroutine() {
@Override
public void apply() throws Exception {
for (StreamEvent event : events) {
producer.enqueue(new QueueEntry(STREAM_EVENT_CODEC.encodePayload(event)));
}
events.clear();
}
});
} catch (TransactionFailureException e) {
throw new IOException(e);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new InterruptedIOException();
}
}
};
}
}