/**
 * 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.wal;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;

import java.io.IOException;
import java.util.HashSet;
import java.util.NavigableMap;
import java.util.Set;
import java.util.TreeMap;
import java.util.concurrent.ThreadLocalRandom;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseClassTestRule;
import org.apache.hadoop.hbase.HBaseTestingUtility;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
import org.apache.hadoop.hbase.client.RegionInfo;
import org.apache.hadoop.hbase.client.RegionInfoBuilder;
import org.apache.hadoop.hbase.client.TableDescriptor;
import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
import org.apache.hadoop.hbase.regionserver.MultiVersionConcurrencyControl;
import org.apache.hadoop.hbase.testclassification.MediumTests;
import org.apache.hadoop.hbase.testclassification.RegionServerTests;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.CommonFSUtils;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.ClassRule;
import org.junit.Rule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.rules.TestName;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Category({RegionServerTests.class, MediumTests.class})
public class TestFSHLogProvider {

  @ClassRule
  public static final HBaseClassTestRule CLASS_RULE =
      HBaseClassTestRule.forClass(TestFSHLogProvider.class);

  private static final Logger LOG = LoggerFactory.getLogger(TestFSHLogProvider.class);

  private static Configuration conf;
  private static FileSystem fs;
  private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
  private MultiVersionConcurrencyControl mvcc;

  @Rule
  public final TestName currentTest = new TestName();

  @Before
  public void setUp() throws Exception {
    mvcc = new MultiVersionConcurrencyControl();
    FileStatus[] entries = fs.listStatus(new Path("/"));
    for (FileStatus dir : entries) {
      fs.delete(dir.getPath(), true);
    }
  }

  @BeforeClass
  public static void setUpBeforeClass() throws Exception {
    // Make block sizes small.
    TEST_UTIL.getConfiguration().setInt("dfs.blocksize", 1024 * 1024);
    // quicker heartbeat interval for faster DN death notification
    TEST_UTIL.getConfiguration().setInt("dfs.namenode.heartbeat.recheck-interval", 5000);
    TEST_UTIL.getConfiguration().setInt("dfs.heartbeat.interval", 1);
    TEST_UTIL.getConfiguration().setInt("dfs.client.socket-timeout", 5000);

    // faster failover with cluster.shutdown();fs.close() idiom
    TEST_UTIL.getConfiguration()
        .setInt("hbase.ipc.client.connect.max.retries", 1);
    TEST_UTIL.getConfiguration().setInt(
        "dfs.client.block.recovery.retries", 1);
    TEST_UTIL.getConfiguration().setInt(
      "hbase.ipc.client.connection.maxidletime", 500);
    TEST_UTIL.startMiniDFSCluster(3);

    // Set up a working space for our tests.
    TEST_UTIL.createRootDir();
    conf = TEST_UTIL.getConfiguration();
    fs = TEST_UTIL.getDFSCluster().getFileSystem();
  }

  @AfterClass
  public static void tearDownAfterClass() throws Exception {
    TEST_UTIL.shutdownMiniCluster();
  }

  static String getName() {
    return "TestDefaultWALProvider";
  }

  @Test
  public void testGetServerNameFromWALDirectoryName() throws IOException {
    ServerName sn = ServerName.valueOf("hn", 450, 1398);
    String hl = CommonFSUtils.getRootDir(conf) + "/" +
        AbstractFSWALProvider.getWALDirectoryName(sn.toString());

    // Must not throw exception
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, null));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
      CommonFSUtils.getRootDir(conf).toUri().toString()));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, ""));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, "                  "));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl + "qdf"));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, "sfqf" + hl + "qdf"));

    final String wals = "/WALs/";
    ServerName parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
      CommonFSUtils.getRootDir(conf).toUri().toString() + wals + sn +
      "/localhost%2C32984%2C1343316388997.1343316390417");
    assertEquals("standard",  sn, parsed);

    parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl + "/qdf");
    assertEquals("subdir", sn, parsed);

    parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
      CommonFSUtils.getRootDir(conf).toUri().toString() + wals + sn +
      "-splitting/localhost%3A57020.1340474893931");
    assertEquals("split", sn, parsed);
  }


  private void addEdits(WAL log, RegionInfo hri, TableDescriptor htd, int times,
      NavigableMap<byte[], Integer> scopes) throws IOException {
    final byte[] row = Bytes.toBytes("row");
    for (int i = 0; i < times; i++) {
      long timestamp = System.currentTimeMillis();
      WALEdit cols = new WALEdit();
      cols.add(new KeyValue(row, row, row, timestamp, row));
      log.appendData(hri,
        getWalKey(hri.getEncodedNameAsBytes(), htd.getTableName(), timestamp, scopes), cols);
    }
    log.sync();
  }

  /**
   * used by TestDefaultWALProviderWithHLogKey
   * @param scopes
   */
  WALKeyImpl getWalKey(final byte[] info, final TableName tableName, final long timestamp,
      NavigableMap<byte[], Integer> scopes) {
    return new WALKeyImpl(info, tableName, timestamp, mvcc, scopes);
  }

  /**
   * helper method to simulate region flush for a WAL.
   * @param wal
   * @param regionEncodedName
   */
  protected void flushRegion(WAL wal, byte[] regionEncodedName, Set<byte[]> flushedFamilyNames) {
    wal.startCacheFlush(regionEncodedName, flushedFamilyNames);
    wal.completeCacheFlush(regionEncodedName);
  }

  @Test
  public void testLogCleaning() throws Exception {
    LOG.info(currentTest.getMethodName());
    TableDescriptor htd =
        TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName()))
            .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
    TableDescriptor htd2 =
        TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "2"))
            .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
    NavigableMap<byte[], Integer> scopes1 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
    for (byte[] fam : htd.getColumnFamilyNames()) {
      scopes1.put(fam, 0);
    }
    NavigableMap<byte[], Integer> scopes2 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
    for (byte[] fam : htd2.getColumnFamilyNames()) {
      scopes2.put(fam, 0);
    }
    Configuration localConf = new Configuration(conf);
    localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
    WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
    try {
      RegionInfo hri = RegionInfoBuilder.newBuilder(htd.getTableName()).build();
      RegionInfo hri2 = RegionInfoBuilder.newBuilder(htd2.getTableName()).build();
      // we want to mix edits from regions, so pick our own identifier.
      WAL log = wals.getWAL(null);

      // Add a single edit and make sure that rolling won't remove the file
      // Before HBASE-3198 it used to delete it
      addEdits(log, hri, htd, 1, scopes1);
      log.rollWriter();
      assertEquals(1, AbstractFSWALProvider.getNumRolledLogFiles(log));

      // See if there's anything wrong with more than 1 edit
      addEdits(log, hri, htd, 2, scopes1);
      log.rollWriter();
      assertEquals(2, FSHLogProvider.getNumRolledLogFiles(log));

      // Now mix edits from 2 regions, still no flushing
      addEdits(log, hri, htd, 1, scopes1);
      addEdits(log, hri2, htd2, 1, scopes2);
      addEdits(log, hri, htd, 1, scopes1);
      addEdits(log, hri2, htd2, 1, scopes2);
      log.rollWriter();
      assertEquals(3, AbstractFSWALProvider.getNumRolledLogFiles(log));

      // Flush the first region, we expect to see the first two files getting
      // archived. We need to append something or writer won't be rolled.
      addEdits(log, hri2, htd2, 1, scopes2);
      log.startCacheFlush(hri.getEncodedNameAsBytes(), htd.getColumnFamilyNames());
      log.completeCacheFlush(hri.getEncodedNameAsBytes());
      log.rollWriter();
      int count = AbstractFSWALProvider.getNumRolledLogFiles(log);
      assertEquals(2, count);

      // Flush the second region, which removes all the remaining output files
      // since the oldest was completely flushed and the two others only contain
      // flush information
      addEdits(log, hri2, htd2, 1, scopes2);
      log.startCacheFlush(hri2.getEncodedNameAsBytes(), htd2.getColumnFamilyNames());
      log.completeCacheFlush(hri2.getEncodedNameAsBytes());
      log.rollWriter();
      assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(log));
    } finally {
      if (wals != null) {
        wals.close();
      }
    }
  }

  /**
   * Tests wal archiving by adding data, doing flushing/rolling and checking we archive old logs
   * and also don't archive "live logs" (that is, a log with un-flushed entries).
   * <p>
   * This is what it does:
   * It creates two regions, and does a series of inserts along with log rolling.
   * Whenever a WAL is rolled, HLogBase checks previous wals for archiving. A wal is eligible for
   * archiving if for all the regions which have entries in that wal file, have flushed - past
   * their maximum sequence id in that wal file.
   * <p>
   * @throws IOException
   */
  @Test
  public void testWALArchiving() throws IOException {
    LOG.debug(currentTest.getMethodName());
    TableDescriptor table1 =
        TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "1"))
            .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
    TableDescriptor table2 =
        TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "2"))
            .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
    NavigableMap<byte[], Integer> scopes1 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
    for (byte[] fam : table1.getColumnFamilyNames()) {
      scopes1.put(fam, 0);
    }
    NavigableMap<byte[], Integer> scopes2 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
    for (byte[] fam : table2.getColumnFamilyNames()) {
      scopes2.put(fam, 0);
    }
    Configuration localConf = new Configuration(conf);
    localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
    WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
    try {
      WAL wal = wals.getWAL(null);
      assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(wal));
      RegionInfo hri1 = RegionInfoBuilder.newBuilder(table1.getTableName()).build();
      RegionInfo hri2 = RegionInfoBuilder.newBuilder(table2.getTableName()).build();
      // variables to mock region sequenceIds.
      // start with the testing logic: insert a waledit, and roll writer
      addEdits(wal, hri1, table1, 1, scopes1);
      wal.rollWriter();
      // assert that the wal is rolled
      assertEquals(1, AbstractFSWALProvider.getNumRolledLogFiles(wal));
      // add edits in the second wal file, and roll writer.
      addEdits(wal, hri1, table1, 1, scopes1);
      wal.rollWriter();
      // assert that the wal is rolled
      assertEquals(2, AbstractFSWALProvider.getNumRolledLogFiles(wal));
      // add a waledit to table1, and flush the region.
      addEdits(wal, hri1, table1, 3, scopes1);
      flushRegion(wal, hri1.getEncodedNameAsBytes(), table1.getColumnFamilyNames());
      // roll log; all old logs should be archived.
      wal.rollWriter();
      assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(wal));
      // add an edit to table2, and roll writer
      addEdits(wal, hri2, table2, 1, scopes2);
      wal.rollWriter();
      assertEquals(1, AbstractFSWALProvider.getNumRolledLogFiles(wal));
      // add edits for table1, and roll writer
      addEdits(wal, hri1, table1, 2, scopes1);
      wal.rollWriter();
      assertEquals(2, AbstractFSWALProvider.getNumRolledLogFiles(wal));
      // add edits for table2, and flush hri1.
      addEdits(wal, hri2, table2, 2, scopes2);
      flushRegion(wal, hri1.getEncodedNameAsBytes(), table2.getColumnFamilyNames());
      // the log : region-sequenceId map is
      // log1: region2 (unflushed)
      // log2: region1 (flushed)
      // log3: region2 (unflushed)
      // roll the writer; log2 should be archived.
      wal.rollWriter();
      assertEquals(2, AbstractFSWALProvider.getNumRolledLogFiles(wal));
      // flush region2, and all logs should be archived.
      addEdits(wal, hri2, table2, 2, scopes2);
      flushRegion(wal, hri2.getEncodedNameAsBytes(), table2.getColumnFamilyNames());
      wal.rollWriter();
      assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(wal));
    } finally {
      if (wals != null) {
        wals.close();
      }
    }
  }

  /**
   * Write to a log file with three concurrent threads and verifying all data is written.
   * @throws Exception
   */
  @Test
  public void testConcurrentWrites() throws Exception {
    // Run the WPE tool with three threads writing 3000 edits each concurrently.
    // When done, verify that all edits were written.
    int errCode = WALPerformanceEvaluation.
      innerMain(new Configuration(TEST_UTIL.getConfiguration()),
        new String [] {"-threads", "3", "-verify", "-noclosefs", "-iterations", "3000"});
    assertEquals(0, errCode);
  }

  /**
   * Ensure that we can use Set.add to deduplicate WALs
   */
  @Test
  public void setMembershipDedups() throws IOException {
    Configuration localConf = new Configuration(conf);
    localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
    WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
    try {
      final Set<WAL> seen = new HashSet<>(1);
      assertTrue("first attempt to add WAL from default provider should work.",
        seen.add(wals.getWAL(null)));
      for (int i = 0; i < 1000; i++) {
        assertFalse(
          "default wal provider is only supposed to return a single wal, which should " +
            "compare as .equals itself.",
          seen.add(wals.getWAL(RegionInfoBuilder
              .newBuilder(TableName.valueOf("Table-" + ThreadLocalRandom.current().nextInt()))
              .build())));
      }
    } finally {
      wals.close();
    }
  }
}