/**
    *
    * 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.wal;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.HColumnDescriptor;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.KeyValue;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.regionserver.MultiVersionConcurrencyControl;
  import org.apache.hadoop.hbase.testclassification.SmallTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.FSUtils;
  import org.apache.hadoop.hbase.wal.WALFactory;
  import org.apache.hadoop.hbase.wal.WAL;
  import org.apache.hadoop.hbase.wal.WALKey;
  import org.junit.After;
  import org.junit.Before;
  import org.junit.BeforeClass;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  import static org.junit.Assert.*;
  
  /**
   * Test that the actions are called while playing with an WAL
   */
  @Category(SmallTests.class)
  public class TestWALActionsListener {
    private static final Log LOG = LogFactory.getLog(TestWALActionsListener.class);
  
    private final static HBaseTestingUtility TEST_UTIL =
        new HBaseTestingUtility();
  
    private final static byte[] SOME_BYTES =  Bytes.toBytes("t");
    private static Configuration conf;
    private static Path rootDir;
    private static Path walRootDir;
    private static FileSystem fs;
    private static FileSystem walFs;
  
    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
      conf = TEST_UTIL.getConfiguration();
      conf.setInt("hbase.regionserver.maxlogs", 5);
      rootDir = TEST_UTIL.createRootDir();
      walRootDir = TEST_UTIL.createWALRootDir();
      fs = FSUtils.getRootDirFileSystem(conf);
      walFs = FSUtils.getWALFileSystem(conf);
    }
  
    @Before
    public void setUp() throws Exception {
      fs.delete(rootDir, true);
      walFs.delete(new Path(walRootDir, HConstants.HREGION_LOGDIR_NAME), true);
      walFs.delete(new Path(walRootDir, HConstants.HREGION_OLDLOGDIR_NAME), true);
    }
  
    @After
    public void tearDown() throws Exception {
      setUp();
    }
  
    /**
     * Add a bunch of dummy data and roll the logs every two insert. We
     * should end up with 10 rolled files (plus the roll called in
     * the constructor). Also test adding a listener while it's running.
     */
    @Test
    public void testActionListener() throws Exception {
      DummyWALActionsListener observer = new DummyWALActionsListener();
      List<WALActionsListener> list = new ArrayList<WALActionsListener>();
      list.add(observer);
     final WALFactory wals = new WALFactory(conf, list, "testActionListener");
     DummyWALActionsListener laterobserver = new DummyWALActionsListener();
     HRegionInfo hri = new HRegionInfo(TableName.valueOf(SOME_BYTES),
              SOME_BYTES, SOME_BYTES, false);
     final WAL wal = wals.getWAL(hri.getEncodedNameAsBytes(), hri.getTable().getNamespace());
     MultiVersionConcurrencyControl mvcc = new MultiVersionConcurrencyControl();
     for (int i = 0; i < 20; i++) {
       byte[] b = Bytes.toBytes(i+"");
       KeyValue kv = new KeyValue(b,b,b);
       WALEdit edit = new WALEdit();
       edit.add(kv);
       HTableDescriptor htd = new HTableDescriptor();
       htd.addFamily(new HColumnDescriptor(b));
 
       final long txid = wal.append(htd, hri, new WALKey(hri.getEncodedNameAsBytes(),
           TableName.valueOf(b), 0, mvcc), edit, true);
       wal.sync(txid);
       if (i == 10) {
         wal.registerWALActionsListener(laterobserver);
       }
       if (i % 2 == 0) {
         wal.rollWriter();
       }
     }
 
     wal.close();
 
     assertEquals(11, observer.preLogRollCounter);
     assertEquals(11, observer.postLogRollCounter);
     assertEquals(5, laterobserver.preLogRollCounter);
     assertEquals(5, laterobserver.postLogRollCounter);
     assertEquals(1, observer.closedCount);
   }
 
 
   /**
    * Just counts when methods are called
    */
   public static class DummyWALActionsListener extends WALActionsListener.Base {
     public int preLogRollCounter = 0;
     public int postLogRollCounter = 0;
     public int closedCount = 0;
 
     @Override
     public void preLogRoll(Path oldFile, Path newFile) {
       preLogRollCounter++;
     }
 
     @Override
     public void postLogRoll(Path oldFile, Path newFile) {
       postLogRollCounter++;
     }
 
     @Override
     public void logCloseRequested() {
       closedCount++;
     }
   }
 
 }