Java Code Examples for org.apache.hadoop.hbase.client.Get#readVersions()

/**
 * Note: this public interface is slightly different from public Java APIs in regard to
 * handling of the qualifier. Here we differ from the public Java API in that null != byte[0].
 * Rather, we respect qual == null as a request for the entire column family. If you want to
 * access the entire column family, use
 * {@link #getVer(ByteBuffer, ByteBuffer, ByteBuffer, int, Map)} with a {@code column} value
 * that lacks a {@code ':'}.
 */
public List<TCell> getVer(ByteBuffer tableName, ByteBuffer row, byte[] family,
    byte[] qualifier, int numVersions, Map<ByteBuffer, ByteBuffer> attributes) throws IOError {

  Table table = null;
  try {
    table = getTable(tableName);
    Get get = new Get(getBytes(row));
    addAttributes(get, attributes);
    if (null == qualifier) {
      get.addFamily(family);
    } else {
      get.addColumn(family, qualifier);
    }
    get.readVersions(numVersions);
    Result result = table.get(get);
    return ThriftUtilities.cellFromHBase(result.rawCells());
  } catch (IOException e) {
    LOG.warn(e.getMessage(), e);
    throw getIOError(e);
  } finally{
    closeTable(table);
  }
}
 

/**
 * Note: this internal interface is slightly different from public APIs in regard to handling
 * of the qualifier. Here we differ from the public Java API in that null != byte[0]. Rather,
 * we respect qual == null as a request for the entire column family. The caller (
 * {@link #getVerTs(ByteBuffer, ByteBuffer, ByteBuffer, long, int, Map)}) interface IS
 * consistent in that the column is parse like normal.
 */
protected List<TCell> getVerTs(ByteBuffer tableName, ByteBuffer row, byte[] family,
    byte[] qualifier, long timestamp, int numVersions, Map<ByteBuffer, ByteBuffer> attributes)
    throws IOError {

  Table table = null;
  try {
    table = getTable(tableName);
    Get get = new Get(getBytes(row));
    addAttributes(get, attributes);
    if (null == qualifier) {
      get.addFamily(family);
    } else {
      get.addColumn(family, qualifier);
    }
    get.setTimeRange(0, timestamp);
    get.readVersions(numVersions);
    Result result = table.get(get);
    return ThriftUtilities.cellFromHBase(result.rawCells());
  } catch (IOException e) {
    LOG.warn(e.getMessage(), e);
    throw getIOError(e);
  } finally{
    closeTable(table);
  }
}
 

/**
 * Creates Get operation for a given backup id
 * @param backupId backup's ID
 * @return get operation
 * @throws IOException exception
 */
private Get createGetForBackupInfo(String backupId) throws IOException {
  Get get = new Get(rowkey(BACKUP_INFO_PREFIX, backupId));
  get.addFamily(BackupSystemTable.SESSIONS_FAMILY);
  get.readVersions(1);
  return get;
}
 

/**
 * Creates Get operation to retrieve start code from backup system table
 * @return get operation
 * @throws IOException exception
 */
private Get createGetForStartCode(String rootPath) throws IOException {
  Get get = new Get(rowkey(START_CODE_ROW, rootPath));
  get.addFamily(BackupSystemTable.META_FAMILY);
  get.readVersions(1);
  return get;
}
 

/**
 * Creates Get to retrieve incremental backup table set from backup system table
 * @return get operation
 * @throws IOException exception
 */
private Get createGetForIncrBackupTableSet(String backupRoot) throws IOException {
  Get get = new Get(rowkey(INCR_BACKUP_SET, backupRoot));
  get.addFamily(BackupSystemTable.META_FAMILY);
  get.readVersions(1);
  return get;
}
 

@Override
public void preGetOp(ObserverContext<RegionCoprocessorEnvironment> c, Get get,
    List<Cell> result) throws IOException {
  TableName tableName = c.getEnvironment().getRegion().getTableDescriptor().getTableName();
  Long ttl = this.ttls.get(tableName);
  if (ttl != null) {
    get.setTimeRange(EnvironmentEdgeManager.currentTime() - ttl, get.getTimeRange().getMax());
  }
  Integer version = this.versions.get(tableName);
  if (version != null) {
    get.readVersions(version);
  }
}
 

@Test
public void testGet() throws Exception {
  byte[] row = Bytes.toBytes("row");
  byte[] fam = Bytes.toBytes("fam");
  byte[] qf1 = Bytes.toBytes("qf1");

  long ts = System.currentTimeMillis();
  int maxVersions = 2;

  Get get = new Get(row);
  get.addColumn(fam, qf1);
  get.setTimeRange(ts, ts + 1);
  get.readVersions(maxVersions);

  ClientProtos.Get getProto = ProtobufUtil.toGet(get);
  Get desGet = ProtobufUtil.toGet(getProto);

  assertTrue(Bytes.equals(get.getRow(), desGet.getRow()));
  Set<byte[]> set = null;
  Set<byte[]> desSet = null;

  for (Map.Entry<byte[], NavigableSet<byte[]>> entry : get.getFamilyMap().entrySet()) {
    assertTrue(desGet.getFamilyMap().containsKey(entry.getKey()));
    set = entry.getValue();
    desSet = desGet.getFamilyMap().get(entry.getKey());
    for (byte[] qualifier : set) {
      assertTrue(desSet.contains(qualifier));
    }
  }

  assertEquals(get.getMaxVersions(), desGet.getMaxVersions());
  TimeRange tr = get.getTimeRange();
  TimeRange desTr = desGet.getTimeRange();
  assertEquals(tr.getMax(), desTr.getMax());
  assertEquals(tr.getMin(), desTr.getMin());
}
 

@Test
public void testMultiGet() throws Exception {
  ArrayList<Get> gets = new ArrayList<>(2);
  gets.add(new Get(ROW_1));
  gets.add(new Get(ROW_2));
  Result[] results = remoteTable.get(gets);
  assertNotNull(results);
  assertEquals(2, results.length);
  assertEquals(1, results[0].size());
  assertEquals(2, results[1].size());

  //Test Versions
  gets = new ArrayList<>(2);
  Get g = new Get(ROW_1);
  g.readVersions(3);
  gets.add(g);
  gets.add(new Get(ROW_2));
  results = remoteTable.get(gets);
  assertNotNull(results);
  assertEquals(2, results.length);
  assertEquals(1, results[0].size());
  assertEquals(3, results[1].size());

  //404
  gets = new ArrayList<>(1);
  gets.add(new Get(Bytes.toBytes("RESALLYREALLYNOTTHERE")));
  results = remoteTable.get(gets);
  assertNotNull(results);
  assertEquals(0, results.length);

  gets = new ArrayList<>(3);
  gets.add(new Get(Bytes.toBytes("RESALLYREALLYNOTTHERE")));
  gets.add(new Get(ROW_1));
  gets.add(new Get(ROW_2));
  results = remoteTable.get(gets);
  assertNotNull(results);
  assertEquals(2, results.length);
}
 

/**
 * Creates a {@link Get} (HBase) from a {@link TGet} (Thrift).
 *
 * This ignores any timestamps set on {@link TColumn} objects.
 *
 * @param in the <code>TGet</code> to convert
 *
 * @return <code>Get</code> object
 *
 * @throws IOException if an invalid time range or max version parameter is given
 */
public static Get getFromThrift(TGet in) throws IOException {
  Get out = new Get(in.getRow());

  // Timestamp overwrites time range if both are set
  if (in.isSetTimestamp()) {
    out.setTimestamp(in.getTimestamp());
  } else if (in.isSetTimeRange()) {
    out.setTimeRange(in.getTimeRange().getMinStamp(), in.getTimeRange().getMaxStamp());
  }

  if (in.isSetMaxVersions()) {
    out.readVersions(in.getMaxVersions());
  }

  if (in.isSetFilterString()) {
    ParseFilter parseFilter = new ParseFilter();
    out.setFilter(parseFilter.parseFilterString(in.getFilterString()));
  }

  if (in.isSetAttributes()) {
    addAttributes(out,in.getAttributes());
  }

  if (in.isSetAuthorizations()) {
    out.setAuthorizations(new Authorizations(in.getAuthorizations().getLabels()));
  }

  if (in.isSetConsistency()) {
    out.setConsistency(consistencyFromThrift(in.getConsistency()));
  }

  if (in.isSetTargetReplicaId()) {
    out.setReplicaId(in.getTargetReplicaId());
  }

  if (in.isSetCacheBlocks()) {
    out.setCacheBlocks(in.isCacheBlocks());
  }
  if (in.isSetStoreLimit()) {
    out.setMaxResultsPerColumnFamily(in.getStoreLimit());
  }
  if (in.isSetStoreOffset()) {
    out.setRowOffsetPerColumnFamily(in.getStoreOffset());
  }
  if (in.isSetExistence_only()) {
    out.setCheckExistenceOnly(in.isExistence_only());
  }

  if (in.isSetColumns()) {
    for (TColumn column : in.getColumns()) {
      if (column.isSetQualifier()) {
        out.addColumn(column.getFamily(), column.getQualifier());
      } else {
        out.addFamily(column.getFamily());
      }
    }
  }

  if (in.isSetFilterBytes()) {
    out.setFilter(filterFromThrift(in.getFilterBytes()));
  }
  return out;
}
 

public void testMultiGet(Connection connection, String tableName) throws Exception {
  createTable(thriftAdmin, tableName);
  try (Table table = connection.getTable(TableName.valueOf(tableName))){
    ArrayList<Get> gets = new ArrayList<>(2);
    gets.add(new Get(ROW_1));
    gets.add(new Get(ROW_2));
    Result[] results = table.get(gets);
    assertNotNull(results);
    assertEquals(2, results.length);
    assertEquals(1, results[0].size());
    assertEquals(2, results[1].size());

    //Test Versions
    gets = new ArrayList<>(2);
    Get g = new Get(ROW_1);
    g.readVersions(3);
    gets.add(g);
    Get get2 = new Get(ROW_2);
    get2.readVersions(3);
    gets.add(get2);
    results = table.get(gets);
    assertNotNull(results);
    assertEquals(2, results.length);
    assertEquals(1, results[0].size());
    assertEquals(3, results[1].size());

    gets = new ArrayList<>(1);
    gets.add(new Get(Bytes.toBytes("RESALLYREALLYNOTTHERE")));
    results = table.get(gets);
    assertNotNull(results);
    assertTrue(results[0].isEmpty());

    gets = new ArrayList<>(3);
    gets.add(new Get(Bytes.toBytes("RESALLYREALLYNOTTHERE")));
    gets.add(new Get(ROW_1));
    gets.add(new Get(ROW_2));
    results = table.get(gets);
    assertNotNull(results);
    assertEquals(3, results.length);
    assertTrue(results[0].isEmpty());
  }

}
 

public RowResultGenerator(final String tableName, final RowSpec rowspec,
    final Filter filter, final boolean cacheBlocks)
    throws IllegalArgumentException, IOException {
  try (Table table = RESTServlet.getInstance().getTable(tableName)) {
    Get get = new Get(rowspec.getRow());
    if (rowspec.hasColumns()) {
      for (byte[] col : rowspec.getColumns()) {
        byte[][] split = CellUtil.parseColumn(col);
        if (split.length == 1) {
          get.addFamily(split[0]);
        } else if (split.length == 2) {
          get.addColumn(split[0], split[1]);
        } else {
          throw new IllegalArgumentException("Invalid column specifier.");
        }
      }
    }
    get.setTimeRange(rowspec.getStartTime(), rowspec.getEndTime());
    get.readVersions(rowspec.getMaxVersions());
    if (filter != null) {
      get.setFilter(filter);
    }
    get.setCacheBlocks(cacheBlocks);
    Result result = table.get(get);
    if (result != null && !result.isEmpty()) {
      valuesI = result.listCells().iterator();
    }
  } catch (DoNotRetryIOException e) {
    // Warn here because Stargate will return 404 in the case if multiple
    // column families were specified but one did not exist -- currently
    // HBase will fail the whole Get.
    // Specifying multiple columns in a URI should be uncommon usage but
    // help to avoid confusion by leaving a record of what happened here in
    // the log.
    LOG.warn(StringUtils.stringifyException(e));
    // Lets get the exception rethrown to get a more meaningful error message than 404
    if (e instanceof AccessDeniedException) {
      throw e;
    }
  }
}