HADOOP-3293. Adding the testcase that I forgot to add earlier.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/core/trunk@718544 13f79535-47bb-0310-9956-ffa450edef68

src/test/org/apache/hadoop/mapred/TestGetSplitHosts.java

@@ -0,0 +1,104 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF 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 org.apache.hadoop.mapred;
+
+import org.apache.hadoop.fs.BlockLocation;
+import junit.framework.TestCase;
+
+public class TestGetSplitHosts extends TestCase {
+
+  public void testGetSplitHosts() throws Exception {
+
+    int numBlocks = 3;
+    int block1Size = 100, block2Size = 150, block3Size = 75;
+    int fileSize = block1Size + block2Size + block3Size;
+    int replicationFactor = 3;
+    
+    BlockLocation[] bs = new BlockLocation[numBlocks];
+    
+    String [] block1Hosts = {"host1","host2","host3"};
+    String [] block1Names = {"host1:100","host2:100","host3:100"};
+    String [] block1Racks = {"/rack1/","/rack1/","/rack2/"};
+    String [] block1Paths = new String[replicationFactor];
+    
+    for (int i = 0; i < replicationFactor; i++) { 
+      block1Paths[i] = block1Racks[i]+block1Names[i];
+    }
+    
+    bs[0] = new BlockLocation(block1Names,block1Hosts,
+                              block1Paths,0,block1Size);
+
+
+    String [] block2Hosts = {"host4","host5","host6"};
+    String [] block2Names = {"host4:100","host5:100","host6:100"};
+    String [] block2Racks = {"/rack2/","/rack3/","/rack3/"};
+    String [] block2Paths = new String[replicationFactor];
+    
+    for (int i = 0; i < replicationFactor; i++) { 
+      block2Paths[i] = block2Racks[i]+block2Names[i];
+    }
+
+    bs[1] = new BlockLocation(block2Names,block2Hosts,
+                              block2Paths,block1Size,block2Size);
+
+    String [] block3Hosts = {"host1","host7","host8"};
+    String [] block3Names = {"host1:100","host7:100","host8:100"};
+    String [] block3Racks = {"/rack1/","/rack4/","/rack4/"};
+    String [] block3Paths = new String[replicationFactor];
+    
+    for (int i = 0; i < replicationFactor; i++) { 
+      block3Paths[i] = block3Racks[i]+block3Names[i];
+    }
+
+    bs[2] = new BlockLocation(block3Names,block3Hosts,
+                              block3Paths,block1Size+block2Size,
+                              block3Size);
+
+    
+    SequenceFileInputFormat< String, String> sif = 
+      new SequenceFileInputFormat<String,String>();
+    String [] hosts = sif.getSplitHosts(bs, 0, fileSize);
+
+    // Contributions By Racks are
+    // Rack1   175       
+    // Rack2   275       
+    // Rack3   150       
+    // So, Rack2 hosts, host4 and host 3 should be returned
+    // even if their individual contribution is not the highest
+
+    assertTrue (hosts.length == replicationFactor);
+    assertTrue(hosts[0].equalsIgnoreCase("host4"));
+    assertTrue(hosts[1].equalsIgnoreCase("host3"));
+    assertTrue(hosts[2].equalsIgnoreCase("host1"));
+    
+    
+    // Now Create the blocks without topology information
+    bs[0] = new BlockLocation(block1Names,block1Hosts,0,block1Size);
+    bs[1] = new BlockLocation(block2Names,block2Hosts,block1Size,block2Size);
+    bs[2] = new BlockLocation(block3Names,block3Hosts,block1Size+block2Size,
+                               block3Size);
+
+    hosts = sif.getSplitHosts(bs, 0, fileSize);
+    
+    // host1 makes the highest contribution among all hosts
+    // So, that should be returned before others
+    
+    assertTrue (hosts.length == replicationFactor);
+    assertTrue(hosts[0].equalsIgnoreCase("host1"));
+  }
+}