HBASE-24898 Use EnvironmentEdge.currentTime() instead of System.currentTimeMillis() in CurrentHourProvider

Closes #2272

Signed-off-by: Nick Dimiduk <ndimiduk@apache.org>
Signed-off-by: Duo Zhang <zhangduo@apache.org>
Signed-off-by: Viraj Jasani <vjasani@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/compactions/CurrentHourProvider.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.hbase.regionserver.compactions;
 import java.util.Calendar;
 import java.util.GregorianCalendar;
 
+import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.apache.yetus.audience.InterfaceAudience;
 
 @InterfaceAudience.Private
@@ -38,6 +39,7 @@ public class CurrentHourProvider {
 
   private static Tick nextTick() {
     Calendar calendar = new GregorianCalendar();
+    calendar.setTimeInMillis(EnvironmentEdgeManager.currentTime());
     int currentHour = calendar.get(Calendar.HOUR_OF_DAY);
     moveToNextHour(calendar);
     return new Tick(currentHour, calendar.getTimeInMillis());
@@ -54,7 +56,7 @@ public class CurrentHourProvider {
 
   public static int getCurrentHour() {
     Tick tick = CurrentHourProvider.tick;
-    if(System.currentTimeMillis() < tick.expirationTimeInMillis) {
+    if (EnvironmentEdgeManager.currentTime() < tick.expirationTimeInMillis) {
       return tick.currentHour;
     }
 

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/compactions/TestCurrentHourProvider.java

@@ -0,0 +1,60 @@
+/**
+ * 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.regionserver.compactions;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.TimeZone;
+import org.apache.hadoop.hbase.HBaseClassTestRule;
+import org.apache.hadoop.hbase.testclassification.RegionServerTests;
+import org.apache.hadoop.hbase.testclassification.SmallTests;
+import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Category({RegionServerTests.class, SmallTests.class})
+public class TestCurrentHourProvider {
+  private static final Logger LOG = LoggerFactory.getLogger(TestCurrentHourProvider.class);
+  @ClassRule
+  public static final HBaseClassTestRule CLASS_RULE =
+      HBaseClassTestRule.forClass(TestCurrentHourProvider.class);
+
+  /**
+   * In timezone GMT+08:00, the unix time of 2020-08-20 11:52:41 is 1597895561000
+   * and the unix time of 2020-08-20 15:04:00 is 1597907081000,
+   * by calculating the delta time to get expected time in current timezone,
+   * then we can get special hour no matter which timezone it runs.
+   */
+  @Test
+  public void testWithEnvironmentEdge() {
+    // set a time represent hour 11
+    long deltaFor11 = TimeZone.getDefault().getRawOffset() - 28800000;
+    long timeFor11 = 1597895561000L - deltaFor11;
+    EnvironmentEdgeManager.injectEdge(() -> timeFor11);
+    assertEquals(11, CurrentHourProvider.getCurrentHour());
+
+    // set a time represent hour 15
+    long deltaFor15 = TimeZone.getDefault().getRawOffset() - 28800000;
+    long timeFor15 = 1597907081000L - deltaFor15;
+    EnvironmentEdgeManager.injectEdge(() -> timeFor15);
+    assertEquals(15, CurrentHourProvider.getCurrentHour());
+  }
+}