HADOOP-8815. RandomDatum needs to override hashCode(). Contributed by Brandon Li.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1389661 13f79535-47bb-0310-9956-ffa450edef68

Conflicts:
	hadoop-common-project/hadoop-common/CHANGES.txt

(cherry picked from commit 3ede27f4557c9e90430a7a3f385b8be243e89688)

Conflicts:
	hadoop-common-project/hadoop-common/CHANGES.txt

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -321,6 +321,9 @@ Release 2.6.0 - UNRELEASED
     HADOOP-10989. Work around buggy getgrouplist() implementations on Linux that
     return 0 on failure. (cnauroth)
 
+    HADOOP-8815. RandomDatum needs to override hashCode().
+    (Brandon Li via suresh)
+
 Release 2.5.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/RandomDatum.java

@@ -21,6 +21,7 @@ package org.apache.hadoop.io;
 import java.io.DataInput;
 import java.io.DataOutput;
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Random;
 
 
@@ -65,6 +66,11 @@ public class RandomDatum implements WritableComparable<RandomDatum> {
     return compareTo((RandomDatum)o) == 0;
   }
 
+  @Override
+  public int hashCode() {
+    return Arrays.hashCode(this.data);
+  }
+  
   private static final char[] HEX_DIGITS =
   {'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
 

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/compress/TestCodec.java

@@ -34,6 +34,8 @@ import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Random;
 import java.util.zip.GZIPInputStream;
 import java.util.zip.GZIPOutputStream;
@@ -226,6 +228,15 @@ public class TestCodec {
       v2.readFields(inflateIn);
       assertTrue("original and compressed-then-decompressed-output not equal",
                  k1.equals(k2) && v1.equals(v2));
+      
+      // original and compressed-then-decompressed-output have the same hashCode
+      Map<RandomDatum, String> m = new HashMap<RandomDatum, String>();
+      m.put(k1, k1.toString());
+      m.put(v1, v1.toString());
+      String result = m.get(k2);
+      assertEquals("k1 and k2 hashcode not equal", result, k1.toString());
+      result = m.get(v2);
+      assertEquals("v1 and v2 hashcode not equal", result, v1.toString());
     }
 
     // De-compress data byte-at-a-time