/**
* Copyright 2013 Netflix, 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 com.netflix.aegisthus.columnar_input.readers;
import rx.Observable;
import rx.exceptions.OnErrorThrowable;
import rx.functions.Func1;
import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.IOError;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.util.Iterator;
import org.apache.cassandra.io.sstable.Descriptor;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.TaskInputOutputContext;
import com.netflix.aegisthus.columnar_input.splits.AegSplit;
import com.netflix.aegisthus.io.commitlog.CommitLogColumnarScanner;
import com.netflix.aegisthus.io.writable.AtomWritable;
import com.netflix.aegisthus.io.writable.CompositeKey;
public class CommitLogRecordReader extends AegisthusRecordReader {
private static final Log LOG = LogFactory.getLog(CommitLogRecordReader.class);
protected CommitLogColumnarScanner scanner;
protected int cfId;
private Iterator<AtomWritable> iterator = null;
@Override
public void close() throws IOException {
super.close();
if (scanner != null) {
scanner.close();
}
}
@SuppressWarnings("rawtypes")
@Override
public void initialize(InputSplit inputSplit, final TaskAttemptContext ctx) throws IOException,
InterruptedException {
AegSplit split = (AegSplit) inputSplit;
start = split.getStart();
end = split.getEnd();
final Path file = split.getPath();
try {
cfId = ctx.getConfiguration().getInt("commitlog.cfid", -1000);
if (cfId == -1000) {
throw new IOException("commitlog.cfid must be set");
}
// open the file and seek to the start of the split
FileSystem fs = file.getFileSystem(ctx.getConfiguration());
FSDataInputStream fileIn = fs.open(split.getPath());
InputStream dis = new BufferedInputStream(fileIn);
scanner = new CommitLogColumnarScanner(new DataInputStream(dis),
Descriptor.fromFilename(split.getPath().getName()).version, cfId);
this.pos = start;
iterator = scanner.observable()
.onErrorFlatMap(new Func1<OnErrorThrowable, Observable<? extends AtomWritable>>() {
@Override
public Observable<? extends AtomWritable> call(OnErrorThrowable onErrorThrowable) {
LOG.error("failure deserializing", onErrorThrowable);
if (ctx instanceof TaskInputOutputContext) {
ctx.getCounter("aegisthus",
onErrorThrowable.getCause().getClass().getSimpleName()).increment(1L);
}
return Observable.empty();
}
})
.toBlocking()
.toIterable()
.iterator();
} catch (IOException e) {
throw new IOError(e);
}
}
@Override
public boolean nextKeyValue() throws IOException, InterruptedException {
if (!iterator.hasNext()) {
return false;
}
AtomWritable atomWritable = iterator.next();
key = new CompositeKey(
ByteBuffer.wrap(atomWritable.getKey()),
atomWritable.getAtom().name(),
atomWritable.getAtom().maxTimestamp()
);
value = atomWritable;
return true;
}
}