Exemple #1
0
  @Test
  public void snapshots() throws RocksDBException {
    RocksDB db = null;
    Options options = null;
    ReadOptions readOptions = null;
    try {

      options = new Options();
      options.setCreateIfMissing(true);

      db = RocksDB.open(options, dbFolder.getRoot().getAbsolutePath());
      db.put("key".getBytes(), "value".getBytes());
      // Get new Snapshot of database
      Snapshot snapshot = db.getSnapshot();
      readOptions = new ReadOptions();
      // set snapshot in ReadOptions
      readOptions.setSnapshot(snapshot);
      // retrieve key value pair
      assertThat(new String(db.get("key".getBytes()))).isEqualTo("value");
      // retrieve key value pair created before
      // the snapshot was made
      assertThat(new String(db.get(readOptions, "key".getBytes()))).isEqualTo("value");
      // add new key/value pair
      db.put("newkey".getBytes(), "newvalue".getBytes());
      // using no snapshot the latest db entries
      // will be taken into account
      assertThat(new String(db.get("newkey".getBytes()))).isEqualTo("newvalue");
      // snapshopot was created before newkey
      assertThat(db.get(readOptions, "newkey".getBytes())).isNull();
      // Retrieve snapshot from read options
      Snapshot sameSnapshot = readOptions.snapshot();
      readOptions.setSnapshot(sameSnapshot);
      // results must be the same with new Snapshot
      // instance using the same native pointer
      assertThat(new String(db.get(readOptions, "key".getBytes()))).isEqualTo("value");
      // update key value pair to newvalue
      db.put("key".getBytes(), "newvalue".getBytes());
      // read with previously created snapshot will
      // read previous version of key value pair
      assertThat(new String(db.get(readOptions, "key".getBytes()))).isEqualTo("value");
      // read for newkey using the snapshot must be
      // null
      assertThat(db.get(readOptions, "newkey".getBytes())).isNull();
      // setting null to snapshot in ReadOptions leads
      // to no Snapshot being used.
      readOptions.setSnapshot(null);
      assertThat(new String(db.get(readOptions, "newkey".getBytes()))).isEqualTo("newvalue");
      // release Snapshot
      db.releaseSnapshot(snapshot);
    } finally {
      if (db != null) {
        db.close();
      }
      if (options != null) {
        options.dispose();
      }
      if (readOptions != null) {
        readOptions.dispose();
      }
    }
  }
  @Override
  public void init() throws DBException {
    System.out.println("Initializing RocksDB...");
    String db_path = DB_PATH;
    options = new Options();
    options
        .setCreateIfMissing(true)
        .createStatistics()
        .setWriteBufferSize(8 * SizeUnit.KB)
        .setMaxWriteBufferNumber(3)
        .setMaxBackgroundCompactions(10)
        .setCompressionType(CompressionType.SNAPPY_COMPRESSION)
        .setCompactionStyle(CompactionStyle.UNIVERSAL);
    Statistics stats = options.statisticsPtr();

    assert (options.createIfMissing() == true);
    assert (options.writeBufferSize() == 8 * SizeUnit.KB);
    assert (options.maxWriteBufferNumber() == 3);
    assert (options.maxBackgroundCompactions() == 10);
    assert (options.compressionType() == CompressionType.SNAPPY_COMPRESSION);
    assert (options.compactionStyle() == CompactionStyle.UNIVERSAL);

    assert (options.memTableFactoryName().equals("SkipListFactory"));
    options.setMemTableConfig(
        new HashSkipListMemTableConfig()
            .setHeight(4)
            .setBranchingFactor(4)
            .setBucketCount(2000000));
    assert (options.memTableFactoryName().equals("HashSkipListRepFactory"));

    options.setMemTableConfig(new HashLinkedListMemTableConfig().setBucketCount(100000));
    assert (options.memTableFactoryName().equals("HashLinkedListRepFactory"));

    options.setMemTableConfig(new VectorMemTableConfig().setReservedSize(10000));
    assert (options.memTableFactoryName().equals("VectorRepFactory"));

    options.setMemTableConfig(new SkipListMemTableConfig());
    assert (options.memTableFactoryName().equals("SkipListFactory"));

    //        options.setTableFormatConfig(new PlainTableConfig());
    //        // Plain-Table requires mmap read
    //        options.setAllowMmapReads(true);
    //        assert(options.tableFactoryName().equals("PlainTable"));
    //
    //        options.setRateLimiterConfig(new GenericRateLimiterConfig(10000000,
    //                10000, 10));
    //        options.setRateLimiterConfig(new GenericRateLimiterConfig(10000000));
    //
    //        Filter bloomFilter = new BloomFilter(10);
    //        BlockBasedTableConfig table_options = new BlockBasedTableConfig();
    //        table_options.setBlockCacheSize(64 * SizeUnit.KB)
    //                .setFilter(bloomFilter)
    //                .setCacheNumShardBits(6)
    //                .setBlockSizeDeviation(5)
    //                .setBlockRestartInterval(10)
    //                .setCacheIndexAndFilterBlocks(true)
    //                .setHashIndexAllowCollision(false)
    //                .setBlockCacheCompressedSize(64 * SizeUnit.KB)
    //                .setBlockCacheCompressedNumShardBits(10);
    //
    //        assert(table_options.blockCacheSize() == 64 * SizeUnit.KB);
    //        assert(table_options.cacheNumShardBits() == 6);
    //        assert(table_options.blockSizeDeviation() == 5);
    //        assert(table_options.blockRestartInterval() == 10);
    //        assert(table_options.cacheIndexAndFilterBlocks() == true);
    //        assert(table_options.hashIndexAllowCollision() == false);
    //        assert(table_options.blockCacheCompressedSize() == 64 * SizeUnit.KB);
    //        assert(table_options.blockCacheCompressedNumShardBits() == 10);
    //
    //        options.setTableFormatConfig(table_options);
    //        assert(options.tableFactoryName().equals("BlockBasedTable"));

    try {
      db = RocksDB.open(options, db_path);
      db.put("hello".getBytes(), "world".getBytes());
      byte[] value = db.get("hello".getBytes());
      assert ("world".equals(new String(value)));
      String str = db.getProperty("rocksdb.stats");
      assert (str != null && str != "");
    } catch (RocksDBException e) {
      System.out.format("[ERROR] caught the unexpceted exception -- %s\n", e);
      assert (db == null);
      assert (false);
    }

    System.out.println("Initializing RocksDB is over");
  }