/**
* Reads back the evaluations.
*
* @param fs File System
* @param conf Job configuration
* @param outpath output <code>Path</code>
* @param evaluations <code>List<Fitness></code> that contains the evaluated fitness for
* each candidate from the input population, sorted in the same order as the candidates.
* @throws IOException
*/
private static void importEvaluations(
FileSystem fs, JobConf conf, Path outpath, List<CDFitness> evaluations) throws IOException {
Sorter sorter = new Sorter(fs, LongWritable.class, CDFitness.class, conf);
// merge and sort the outputs
Path[] outfiles = OutputUtils.listOutputFiles(fs, outpath);
Path output = new Path(outpath, "output.sorted");
sorter.merge(outfiles, output);
// import the evaluations
LongWritable key = new LongWritable();
CDFitness value = new CDFitness();
Reader reader = new Reader(fs, output, conf);
while (reader.next(key, value)) {
evaluations.add(new CDFitness(value));
}
reader.close();
}
public static void main(String[] args) throws IOException {
Configuration conf = new Configuration();
Path p = new Path("hdfs://localhost:9000/testsort/data.seq");
// URI uri = new File(".").getAbsoluteFile().toURI();
// Path local = new Path(uri);
// Path p = new Path(new Path(local, "tmp"), "data.seq");
// {
// Writer writer = SequenceFile.createWriter(conf,
// Writer.valueClass(LongWritable.class),
// Writer.keyClass(BytesWritable.class), Writer.file(p));
//
// LongWritable value = new LongWritable();
// BytesWritable key = new BytesWritable();
// Random random = new Random(1);
// byte[] buf = new byte[50];
// for (int i = 0; i < 10000000; i++) {
// value.set(random.nextLong());
// random.nextBytes(buf);
// key.set(buf, 0, buf.length);
// writer.append(key, value);
// }
// writer.close();
// }
// {
// // io.seqfile.local.dir
// URI uri = new File(".").getAbsoluteFile().toURI();
// Path local = new Path(uri);
//
// conf.set("io.seqfile.local.dir", new Path(local, "tmp").toString());
// Path tempDir = new Path(p.getParent(), "tmp");
// Sorter sorter = new SequenceFile.Sorter(p.getFileSystem(conf),
// BytesWritable.class, LongWritable.class, conf);
// sorter.setMemory(10 * 1024 * 1024);
// // Path tempDir = new Path(p.getParent(), "tmp");
//
// RawKeyValueIterator iterate = sorter.sortAndIterate(new Path[] { p },
// tempDir, false);
// Path sortedPath = new Path(p.getParent(), "sorted.seq");
// Writer writer = SequenceFile.createWriter(conf,
// Writer.valueClass(LongWritable.class),
// Writer.keyClass(BytesWritable.class), Writer.file(sortedPath));
// while (iterate.next()) {
// DataOutputBuffer key = iterate.getKey();
// byte[] keyData = key.getData();
// int keyOffset = 0;
// int keyLength = key.getLength();
// ValueBytes val = iterate.getValue();
// writer.appendRaw(keyData, keyOffset, keyLength, val);
// }
// writer.close();
// }
{
conf.setInt("io.sort.factor", 1000);
Sorter sorter =
new SequenceFile.Sorter(
p.getFileSystem(conf), BytesWritable.class, LongWritable.class, conf);
sorter.setMemory(10 * 1024 * 1024);
sorter.sort(new Path[] {p}, new Path(p.getParent(), "sorted.seq"), false);
}
}