/**
* Licensed to Odiago, Inc. under one or more contributor license
* agreements. See the NOTICE.txt file distributed with this work for
* additional information regarding copyright ownership. Odiago, Inc.
* 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 com.odiago.flumebase.exec.local;
import java.io.IOException;
import java.lang.InterruptedException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.cloudera.flume.core.Event;
import com.odiago.flumebase.exec.EventWrapper;
import com.odiago.flumebase.exec.FlowElementContext;
import com.odiago.flumebase.exec.FlowElementImpl;
import com.odiago.flumebase.exec.InMemStreamSymbol;
import com.odiago.flumebase.exec.ParsingEventWrapper;
import com.odiago.flumebase.parser.TypedField;
/**
* Generates events from a pre-populated in-memory buffer.
* Used for testing flows.
*/
public class LocalInMemSourceElement extends FlowElementImpl {
private static final Logger LOG = LoggerFactory.getLogger(
LocalInMemSourceElement.class.getName());
/** The stream generating the events. */
private InMemStreamSymbol mStreamSymbol;
/** Fields of the input event. */
private List<String> mFieldNames;
/** Additional thread that actually drives event generation. */
private class EventGenThread extends Thread {
public void run() {
Iterator<Event> iter = mStreamSymbol.getEvents();
FlowElementContext context = getContext();
try {
// Iterate over all the input events, and wrap them in
// a parsing EventWrapper; advance these to the output.
while (iter.hasNext()) {
Event rawEvent = iter.next();
rawEvent.set(STREAM_NAME_ATTR, mStreamSymbol.getName().getBytes());
EventWrapper wrapper = new ParsingEventWrapper(mStreamSymbol.getEventParser(),
mFieldNames);
wrapper.reset(rawEvent);
context.emit(wrapper);
}
} catch (IOException ioe) {
LOG.error("IOException emitting event: " + ioe);
} catch (InterruptedException ie) {
LOG.error("Interrupted emitting event: " + ie);
} finally {
try {
getContext().notifyCompletion();
} catch (IOException ioe) {
LOG.warn("IOException sending completion notice: " + ioe);
} catch (InterruptedException ie) {
LOG.warn("InterruptedException sending completion notice: " + ie);
}
}
}
}
private EventGenThread mEventGenThread;
public LocalInMemSourceElement(FlowElementContext context,
List<TypedField> fields, InMemStreamSymbol streamSymbol) {
super(context);
mStreamSymbol = streamSymbol;
mFieldNames = new ArrayList<String>();
for (TypedField field : fields) {
mFieldNames.add(field.getAvroName());
}
}
@Override
public void takeEvent(EventWrapper e) {
throw new RuntimeException("LocalInMemSourceElement does not expect takeEvent()");
}
@Override
public void open() throws IOException, InterruptedException {
super.open();
if (null != mEventGenThread) {
throw new IOException("LocalInMemSourceElement.open() called multiple times");
}
mEventGenThread = new EventGenThread();
mEventGenThread.start();
}
@Override
public void close() throws IOException, InterruptedException {
mEventGenThread.join();
super.close();
}
@Override
public String toString() {
return "InMemStreamSource[mStream=\"" + mStreamSymbol.getName() + "\"]";
}
}