HBASE-25622 Result#compareResults should compare tags. (#3004)

Signed-off-by Anoop Sam John <anoopsamjohn@apache.org>

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Result.java

@@ -855,7 +855,8 @@ public class Result implements CellScannable, CellScanner {
     Cell[] replicatedKVs = res2.rawCells();
     for (int i = 0; i < res1.size(); i++) {
       if (!ourKVs[i].equals(replicatedKVs[i]) ||
-          !CellUtil.matchingValue(ourKVs[i], replicatedKVs[i])) {
+          !CellUtil.matchingValue(ourKVs[i], replicatedKVs[i]) ||
+          !CellUtil.matchingTags(ourKVs[i], replicatedKVs[i])) {
         throw new Exception("This result was different: "
             + res1.toString() + " compared to " + res2.toString());
       }

hbase-common/src/main/java/org/apache/hadoop/hbase/CellUtil.java

@@ -470,6 +470,14 @@ public final class CellUtil {
         buf.length);
   }
 
+  /*
+    Compares tags in both cells.
+   */
+  public static boolean matchingTags(final Cell left, final Cell right) {
+    return Bytes.equals(left.getTagsArray(), left.getTagsOffset(), left.getTagsLength(),
+        right.getTagsArray(), right.getTagsOffset(), right.getTagsLength());
+  }
+
   public static boolean matchingTimestamp(Cell a, Cell b) {
     return CellComparator.compareTimestamps(a, b) == 0;
   }

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestResult.java

@@ -34,10 +34,13 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellScanner;
 import org.apache.hadoop.hbase.CellUtil;
+import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.Tag;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos;
 import org.apache.hadoop.hbase.testclassification.SmallTests;
 import org.apache.hadoop.hbase.util.Bytes;
+import org.junit.Test;
 import org.junit.experimental.categories.Category;
 
 @Category(SmallTests.class)
@@ -247,6 +250,50 @@ public class TestResult extends TestCase {
     }
   }
 
+  /**
+   *  Test Result#compareResults when tags are present.
+   * @throws Exception Exception
+   */
+  @Test
+  public void testCompareResultsWithTags() throws Exception {
+    byte[] qualifier = Bytes.toBytes("q");
+    String tagValue1 = "tagV1";
+    String tagValue2 = "tagV2";
+    // Create cell with 2 tags
+    KeyValue kv1 = new KeyValue(row, family, qualifier, HConstants.LATEST_TIMESTAMP,
+      value, new Tag[] {new Tag((byte) 1, tagValue1), new Tag((byte) 2, tagValue2)});
+
+    // Create cell with no tags.
+    KeyValue kv2 = new KeyValue(row, family, qualifier, HConstants.LATEST_TIMESTAMP,
+      value);
+
+    Result r1 = Result.create(new KeyValue[] {kv1});
+    Result r2 = Result.create(new KeyValue[] {kv2});
+    // Compare result with self.
+    Result.compareResults(r1, r1);
+
+    try {
+      // Compare result with 2 tags v/s no tags.
+      Result.compareResults(r1, r2);
+      fail();
+    } catch (Exception e) {
+      assertTrue(e.getMessage().startsWith("This result was different:"));
+    }
+
+    // Create cell with just 1 tag.
+    String tagValue3 = "tagV3";
+    KeyValue kv3 = new KeyValue(row, family, qualifier, HConstants.LATEST_TIMESTAMP,
+      value, new Tag[] {new Tag((byte) 1, tagValue3)});
+    Result r3 = Result.create(new KeyValue[] {kv3});
+    try {
+      // Compare result with 2 tags v/s 1 tag.
+      Result.compareResults(r1, r3);
+      fail();
+    } catch (Exception e) {
+      assertTrue(e.getMessage().startsWith("This result was different:"));
+    }
+  }
+
   /**
    * Verifies that one can't modify instance of EMPTY_RESULT.
    */