HBASE-22766 Code Coverage Improvement: Create Unit Tests for ResultSt…

…atsUtil (#520)

Signed-off-by: Jan Hentschel <jan.hentschel@ultratendency.com>
Signed-off-by: Duo Zhang <zhangduo@apache.org>

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

@@ -17,63 +17,30 @@
  */
 package org.apache.hadoop.hbase.client;
 
-import org.apache.hadoop.hbase.HRegionLocation;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.yetus.audience.InterfaceAudience;
 
 /**
- * A {@link Result} with some statistics about the server/region status
+ * Statistics update about a server/region
  */
 @InterfaceAudience.Private
 public final class ResultStatsUtil {
-
   private ResultStatsUtil() {
     //private ctor for util class
   }
 
   /**
-   * Update the stats for the specified region if the result is an instance of {@link
-   * ResultStatsUtil}
+   * Update the statistics for the specified region.
    *
-   * @param r object that contains the result and possibly the statistics about the region
-   * @param serverStats stats tracker to update from the result
+   * @param tracker tracker to update
    * @param server server from which the result was obtained
-   * @param regionName full region name for the stats.
-   * @return the underlying {@link Result} if the passed result is an {@link
-   * ResultStatsUtil} or just returns the result;
+   * @param regionName full region name for the statistics
+   * @param stats statistics to update for the specified region
    */
-  public static <T> T updateStats(T r, ServerStatisticTracker serverStats,
-      ServerName server, byte[] regionName) {
-    if (!(r instanceof Result)) {
-      return r;
-    }
-    Result result = (Result) r;
-    // early exit if there are no stats to collect
-    RegionLoadStats stats = result.getStats();
-    if(stats == null){
-      return r;
-    }
-
-    updateStats(serverStats, server, regionName, stats);
-    return r;
-  }
-
   public static void updateStats(StatisticTrackable tracker, ServerName server, byte[] regionName,
     RegionLoadStats stats) {
     if (regionName != null && stats != null && tracker != null) {
       tracker.updateRegionStats(server, regionName, stats);
     }
   }
-
-  public static <T> T updateStats(T r, ServerStatisticTracker stats,
-      HRegionLocation regionLocation) {
-    byte[] regionName = null;
-    ServerName server = null;
-    if (regionLocation != null) {
-      server = regionLocation.getServerName();
-      regionName = regionLocation.getRegionInfo().getRegionName();
-    }
-
-    return updateStats(r, stats, server, regionName);
-  }
 }

hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestResultStatsUtil.java

@@ -0,0 +1,91 @@
+/**
+ * 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.hbase.client;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+import org.apache.hadoop.hbase.HBaseClassTestRule;
+import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.client.backoff.ServerStatistics;
+import org.apache.hadoop.hbase.testclassification.ClientTests;
+import org.apache.hadoop.hbase.testclassification.SmallTests;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category({ClientTests.class, SmallTests.class})
+public class TestResultStatsUtil {
+  @ClassRule
+  public static final HBaseClassTestRule CLASS_RULE =
+          HBaseClassTestRule.forClass(TestResultStatsUtil.class);
+
+  private static final RegionLoadStats regionLoadStats = new RegionLoadStats(100,
+          10,90);
+  private static final byte[] regionName = {80};
+  private static final ServerName server = ServerName.parseServerName("3.1.yg.n,50,1");
+
+  @Test
+  public void testUpdateStats() {
+    // Create a tracker
+    ServerStatisticTracker serverStatisticTracker = new ServerStatisticTracker();
+
+    // Pass in the tracker for update
+    ResultStatsUtil.updateStats(serverStatisticTracker, server, regionName, regionLoadStats);
+
+    // Check that the tracker was updated as expected
+    ServerStatistics stats = serverStatisticTracker.getStats(server);
+
+    assertEquals(regionLoadStats.memstoreLoad, stats.getStatsForRegion(regionName)
+            .getMemStoreLoadPercent());
+    assertEquals(regionLoadStats.compactionPressure, stats.getStatsForRegion(regionName)
+            .getCompactionPressure());
+    assertEquals(regionLoadStats.heapOccupancy, stats.getStatsForRegion(regionName)
+            .getHeapOccupancyPercent());
+  }
+
+  @Test
+  public void testUpdateStatsRegionNameNull() {
+    ServerStatisticTracker serverStatisticTracker = new ServerStatisticTracker();
+
+    ResultStatsUtil.updateStats(serverStatisticTracker, server, null, regionLoadStats);
+
+    ServerStatistics stats = serverStatisticTracker.getStats(server);
+    assertNull(stats);
+  }
+
+  @Test
+  public void testUpdateStatsStatsNull() {
+    ServerStatisticTracker serverStatisticTracker = new ServerStatisticTracker();
+
+    ResultStatsUtil.updateStats(serverStatisticTracker, server, regionName, null);
+
+    ServerStatistics stats = serverStatisticTracker.getStats(server);
+    assertNull(stats);
+  }
+
+  @Test
+  public void testUpdateStatsTrackerNull() {
+    ServerStatisticTracker serverStatisticTracker = new ServerStatisticTracker();
+
+    ResultStatsUtil.updateStats(null, server, regionName, regionLoadStats);
+
+    ServerStatistics stats = serverStatisticTracker.getStats(server);
+    assertNull(stats);
+  }
+}