/**
    *
    * 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.util;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertNull;
  import static org.junit.Assert.assertTrue;
  
  import java.io.IOException;
  import java.util.UUID;
  import java.util.Set;
  import java.util.HashSet;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.fs.FSDataOutputStream;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.testclassification.MediumTests;
  import org.apache.hadoop.hbase.wal.WALSplitter;
  import org.junit.*;
  import org.junit.experimental.categories.Category;
  
  /**
   * Test {@link FSUtils}.
   */
  @Category(MediumTests.class)
  public class TestFSVisitor {
    private static final Log LOG = LogFactory.getLog(TestFSVisitor.class);
  
    private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
  
    private final String TABLE_NAME = "testtb";
  
    private Set<String> tableFamilies;
    private Set<String> tableRegions;
    private Set<String> tableHFiles;
  
    private FileSystem fs;
    private Path tableDir;
    private Path rootDir;
  
    @Before
    public void setUp() throws Exception {
      fs = FileSystem.get(TEST_UTIL.getConfiguration());
      rootDir = TEST_UTIL.getDataTestDir("hbase");
  
      tableFamilies = new HashSet<String>();
      tableRegions = new HashSet<String>();
      tableHFiles = new HashSet<String>();
      tableDir = createTableFiles(rootDir, TABLE_NAME, tableRegions, tableFamilies, tableHFiles);
      FSUtils.logFileSystemState(fs, rootDir, LOG);
    }
  
    @After
    public void tearDown() throws Exception {
      fs.delete(rootDir, true);
    }
  
    @Test
    public void testVisitStoreFiles() throws IOException {
      final Set<String> regions = new HashSet<String>();
      final Set<String> families = new HashSet<String>();
      final Set<String> hfiles = new HashSet<String>();
      FSVisitor.visitTableStoreFiles(fs, tableDir, new FSVisitor.StoreFileVisitor() {
        public void storeFile(final String region, final String family, final String hfileName)
            throws IOException {
          regions.add(region);
          families.add(family);
          hfiles.add(hfileName);
        }
      });
      assertEquals(tableRegions, regions);
      assertEquals(tableFamilies, families);
      assertEquals(tableHFiles, hfiles);
    }
  
    /*
     * |-testtb/
    * |----f1d3ff8443297732862df21dc4e57262/
    * |-------f1/
    * |----------d0be84935ba84b66b1e866752ec5d663
    * |----------9fc9d481718f4878b29aad0a597ecb94
    * |-------f2/
    * |----------4b0fe6068c564737946bcf4fd4ab8ae1
    */
   private Path createTableFiles(final Path rootDir, final String tableName,
       final Set<String> tableRegions, final Set<String> tableFamilies,
       final Set<String> tableHFiles) throws IOException {
     Path tableDir = new Path(rootDir, tableName);
     for (int r = 0; r < 10; ++r) {
       String regionName = MD5Hash.getMD5AsHex(Bytes.toBytes(r));
       tableRegions.add(regionName);
       Path regionDir = new Path(tableDir, regionName);
       for (int f = 0; f < 3; ++f) {
         String familyName = "f" + f;
         tableFamilies.add(familyName);
         Path familyDir = new Path(regionDir, familyName);
         fs.mkdirs(familyDir);
         for (int h = 0; h < 5; ++h) {
          String hfileName = UUID.randomUUID().toString().replaceAll("-", "");
          tableHFiles.add(hfileName);
          fs.createNewFile(new Path(familyDir, hfileName));
         }
       }
     }
     return tableDir;
   }
 }