Locations are built when adding splits

src/main/java/es/udc/gac/hadoop/sequence/parser/mapreduce/PairedEndInputSplit.java

@@ -22,9 +22,9 @@
 import java.io.DataOutput;
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.HashSet;
 import java.util.List;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.io.Writable;
@@ -37,15 +37,18 @@ public class PairedEndInputSplit extends FileSplit implements Writable {
 
 	private static final int LENGTH = 2;
 
-	private int fill = 0;
-	private long totsize = 0L;
+	private int fill;
+	private long totsize;
 	private FileSplit[] splits;
 	private List<List<String>> allHosts;
 	private String[] hosts;
 
 	public PairedEndInputSplit() {
 		splits = new FileSplit[LENGTH];
 		allHosts = new ArrayList<List<String>>(LENGTH);
+		hosts = null;
+		fill = 0;
+		totsize = 0L;
 
 		for (int i = 0; i < LENGTH; i++)
 			allHosts.add(new ArrayList<String>());
@@ -63,9 +66,6 @@ public void add(FileSplit s) throws IOException, InterruptedException {
 			throw new IOException("Too many splits");
 		}
 
-		splits[fill] = s;
-		totsize += s.getLength();
-
 		String[] hints = s.getLocations();
 
 		if (hints != null && hints.length > 0) {
@@ -74,14 +74,23 @@ public void add(FileSplit s) throws IOException, InterruptedException {
 			}
 		}
 
-		fill++;
+		splits[fill++] = s;
+		totsize += s.getLength();
 
 		if (fill == LENGTH) {
 			List<String> intersect = allHosts.get(0).stream()
 					.filter(allHosts.get(1)::contains)
 					.collect(Collectors.toList());
 
-			hosts = intersect.toArray(new String[intersect.size()]);
+			if (intersect.size() > 0) {
+				hosts = intersect.toArray(new String[intersect.size()]);
+			} else {
+				List<String> union = Stream.concat(allHosts.get(0).stream(), allHosts.get(1).stream())
+						.distinct()
+						.collect(Collectors.toList());
+
+				hosts = union.toArray(new String[union.size()]);
+			}
 		}
 	}
 
@@ -140,22 +149,7 @@ public String toString() {
 	 */
 	@Override
 	public String[] getLocations() throws IOException {
-		if (hosts.length > 0)
-			return hosts;
-
-		HashSet<String> hostsSet = new HashSet<String>();
-
-		for (int i = 0; i < splits.length; i++) {
-			String[] hints = splits[i].getLocations();
-
-			if (hints != null && hints.length > 0) {
-				for (String host : hints) {
-					hostsSet.add(host);
-				}
-			}
-		}
-
-		return hostsSet.toArray(new String[hostsSet.size()]);
+		return hosts;
 	}
 
 	/**