/**
    * 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.assertNotEquals;
  import static org.junit.Assert.assertNull;
  import static org.junit.Assert.assertTrue;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.client.ConnectionManager.HConnectionImplementation;
  import org.apache.hadoop.hbase.testclassification.ClientTests;
  import org.apache.hadoop.hbase.testclassification.MediumTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.junit.AfterClass;
  import org.junit.BeforeClass;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  @Category({MediumTests.class, ClientTests.class})
  public class TestRegionLocationCaching {
  
    private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
    private static int SLAVES = 1;
    private static int PER_REGIONSERVER_QUEUE_SIZE = 100000;
    private static TableName TABLE_NAME = TableName.valueOf("TestRegionLocationCaching");
    private static byte[] FAMILY = Bytes.toBytes("testFamily");
    private static byte[] QUALIFIER = Bytes.toBytes("testQualifier");
  
    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
      TEST_UTIL.startMiniCluster(SLAVES);
      TEST_UTIL.createTable(TABLE_NAME, new byte[][] { FAMILY });
      TEST_UTIL.waitUntilAllRegionsAssigned(TABLE_NAME);
    }
  
    @AfterClass
    public static void tearDownAfterClass() throws Exception {
      TEST_UTIL.shutdownMiniCluster();
    }
  
    @Test
    public void testCachingForHTableMultiplexerSinglePut() throws Exception {
      HTableMultiplexer multiplexer =
          new HTableMultiplexer(TEST_UTIL.getConfiguration(), PER_REGIONSERVER_QUEUE_SIZE);
      byte[] row = Bytes.toBytes("htable_multiplexer_single_put");
      byte[] value = Bytes.toBytes("value");
  
      Put put = new Put(row);
      put.addColumn(FAMILY, QUALIFIER, value);
      assertTrue("Put request not accepted by multiplexer queue", multiplexer.put(TABLE_NAME, put));
  
      checkRegionLocationIsCached(TABLE_NAME, multiplexer.getConnection());
      checkExistence(TABLE_NAME, row, FAMILY, QUALIFIER);
  
      multiplexer.close();
    }
  
    @Test
    public void testCachingForHTableMultiplexerMultiPut() throws Exception {
      HTableMultiplexer multiplexer =
          new HTableMultiplexer(TEST_UTIL.getConfiguration(), PER_REGIONSERVER_QUEUE_SIZE);
  
      List<Put> multiput = new ArrayList<Put>();
      for (int i = 0; i < 10; i++) {
        Put put = new Put(Bytes.toBytes("htable_multiplexer_multi_put" + i));
        byte[] value = Bytes.toBytes("value_" + i);
        put.addColumn(FAMILY, QUALIFIER, value);
        multiput.add(put);
      }
  
      List<Put> failedPuts = multiplexer.put(TABLE_NAME, multiput);
      assertNull("All put requests were not accepted by multiplexer queue", failedPuts);
  
      checkRegionLocationIsCached(TABLE_NAME, multiplexer.getConnection());
      for (int i = 0; i < 10; i++) {
        checkExistence(TABLE_NAME, Bytes.toBytes("htable_multiplexer_multi_put" + i), FAMILY,
          QUALIFIER);
      }
 
     multiplexer.close();
   }
 
   @Test
   public void testCachingForHTableSinglePut() throws Exception {
     byte[] row = Bytes.toBytes("htable_single_put");
     byte[] value = Bytes.toBytes("value");
 
     Put put = new Put(row);
     put.addColumn(FAMILY, QUALIFIER, value);
 
     try (Table table = TEST_UTIL.getConnection().getTable(TABLE_NAME)) {
       table.put(put);
     }
 
     checkRegionLocationIsCached(TABLE_NAME, TEST_UTIL.getConnection());
     checkExistence(TABLE_NAME, row, FAMILY, QUALIFIER);
   }
 
   @Test
   public void testCachingForHTableMultiPut() throws Exception {
     List<Put> multiput = new ArrayList<Put>();
     for (int i = 0; i < 10; i++) {
       Put put = new Put(Bytes.toBytes("htable_multi_put" + i));
       byte[] value = Bytes.toBytes("value_" + i);
       put.addColumn(FAMILY, QUALIFIER, value);
       multiput.add(put);
     }
 
     try (Table table = TEST_UTIL.getConnection().getTable(TABLE_NAME)) {
       table.put(multiput);
     }
     checkRegionLocationIsCached(TABLE_NAME, TEST_UTIL.getConnection());
     for (int i = 0; i < 10; i++) {
       checkExistence(TABLE_NAME, Bytes.toBytes("htable_multi_put" + i), FAMILY, QUALIFIER);
     }
   }
 
   /**
    * Method to check whether the cached region location is non-empty for the given table. It repeats
    * the same check several times as clearing of cache by some async operations may not reflect
    * immediately.
    */
   private void checkRegionLocationIsCached(final TableName tableName, final Connection conn)
       throws InterruptedException, IOException {
     for (int count = 0; count < 50; count++) {
       int number = ((HConnectionImplementation) conn).getNumberOfCachedRegionLocations(tableName);
       assertNotEquals("Expected non-zero number of cached region locations", 0, number);
       Thread.sleep(100);
     }
   }
 
   /**
    * Method to check whether the passed row exists in the given table
    */
   private static void checkExistence(final TableName tableName, final byte[] row,
       final byte[] family, final byte[] qualifier) throws Exception {
     // verify that the row exists
     Result r;
     Get get = new Get(row);
     get.addColumn(family, qualifier);
     int nbTry = 0;
     try (Table table = TEST_UTIL.getConnection().getTable(tableName)) {
       do {
         assertTrue("Failed to get row after " + nbTry + " tries", nbTry < 50);
         nbTry++;
         Thread.sleep(100);
         r = table.get(get);
       } while (r == null || r.getValue(family, qualifier) == null);
     }
   }
 }