Java Code Examples for org.apache.hadoop.hbase.client.RegionInfo#createRegionName()

/**
 * Performs a scan of META table for given table starting from given row.
 * @param connection connection we're using
 * @param visitor visitor to call
 * @param tableName table withing we scan
 * @param row start scan from this row
 * @param rowLimit max number of rows to return
 */
public static void scanMeta(Connection connection, final ClientMetaTableAccessor.Visitor visitor,
  final TableName tableName, final byte[] row, final int rowLimit) throws IOException {
  byte[] startRow = null;
  byte[] stopRow = null;
  if (tableName != null) {
    startRow = ClientMetaTableAccessor.getTableStartRowForMeta(tableName, QueryType.REGION);
    if (row != null) {
      RegionInfo closestRi = getClosestRegionInfo(connection, tableName, row);
      startRow =
        RegionInfo.createRegionName(tableName, closestRi.getStartKey(), HConstants.ZEROES, false);
    }
    stopRow = ClientMetaTableAccessor.getTableStopRowForMeta(tableName, QueryType.REGION);
  }
  scanMeta(connection, startRow, stopRow, QueryType.REGION, rowLimit, visitor);
}
 

/**
 * @return Get closest metatable region row to passed <code>row</code>
 */
@NonNull
private static RegionInfo getClosestRegionInfo(Connection connection,
  @NonNull final TableName tableName, @NonNull final byte[] row) throws IOException {
  byte[] searchRow = RegionInfo.createRegionName(tableName, row, HConstants.NINES, false);
  Scan scan = getMetaScan(connection, 1);
  scan.setReversed(true);
  scan.withStartRow(searchRow);
  try (ResultScanner resultScanner = getMetaHTable(connection).getScanner(scan)) {
    Result result = resultScanner.next();
    if (result == null) {
      throw new TableNotFoundException("Cannot find row in META " + " for table: " + tableName +
        ", row=" + Bytes.toStringBinary(row));
    }
    RegionInfo regionInfo = CatalogFamilyFormat.getRegionInfo(result);
    if (regionInfo == null) {
      throw new IOException("RegionInfo was null or empty in Meta for " + tableName + ", row=" +
        Bytes.toStringBinary(row));
    }
    return regionInfo;
  }
}
 

public static void doTestGetRegionInfo(Hbase.Iface handler) throws Exception {
  // Create tableA and add two columns to rowA
  handler.createTable(tableAname, getColumnDescriptors());
  try {
    handler.mutateRow(tableAname, rowAname, getMutations(), null);
    byte[] searchRow = RegionInfo.createRegionName(
        TableName.valueOf(tableAname.array()), rowAname.array(),
        HConstants.NINES, false);
    TRegionInfo regionInfo = handler.getRegionInfo(ByteBuffer.wrap(searchRow));
    assertTrue(Bytes.toStringBinary(regionInfo.getName()).startsWith(
          Bytes.toStringBinary(tableAname)));
  } finally {
    handler.disableTable(tableAname);
    handler.deleteTable(tableAname);
  }
}
 

/**
 * @param answer Pass -1 if we're not to find anything.
 * @return Row found.
 */
private byte[] findRow(final Region mr, final char table, final int rowToFind, final int answer)
  throws IOException {
  TableName tableb = TableName.valueOf("" + table);
  // Find the row.
  byte[] tofindBytes = Bytes.toBytes((short) rowToFind);
  byte[] metaKey = RegionInfo.createRegionName(tableb, tofindBytes, HConstants.NINES, false);
  LOG.info("find=" + new String(metaKey, StandardCharsets.UTF_8));
  Result r = UTIL.getClosestRowBefore(mr, metaKey, HConstants.CATALOG_FAMILY);
  if (answer == -1) {
    assertNull(r);
    return null;
  }
  assertTrue(
    Bytes.compareTo(Bytes.toBytes((short) answer), extractRowFromMetaRow(r.getRow())) == 0);
  return r.getRow();
}
 

public static ReplicationBarrierResult getReplicationBarrierResult(Connection conn,
  TableName tableName, byte[] row, byte[] encodedRegionName) throws IOException {
  byte[] metaStartKey = RegionInfo.createRegionName(tableName, row, HConstants.NINES, false);
  byte[] metaStopKey =
    RegionInfo.createRegionName(tableName, HConstants.EMPTY_START_ROW, "", false);
  Scan scan = new Scan().withStartRow(metaStartKey).withStopRow(metaStopKey)
    .addColumn(HConstants.CATALOG_FAMILY, HConstants.STATE_QUALIFIER)
    .addFamily(HConstants.REPLICATION_BARRIER_FAMILY).readAllVersions().setReversed(true)
    .setCaching(10);
  try (Table table = getMetaHTable(conn); ResultScanner scanner = table.getScanner(scan)) {
    for (Result result;;) {
      result = scanner.next();
      if (result == null) {
        return new ReplicationBarrierResult(new long[0], null, Collections.emptyList());
      }
      byte[] regionName = result.getRow();
      // TODO: we may look up a region which has already been split or merged so we need to check
      // whether the encoded name matches. Need to find a way to quit earlier when there is no
      // record for the given region, for now it will scan to the end of the table.
      if (!Bytes.equals(encodedRegionName,
        Bytes.toBytes(RegionInfo.encodeRegionName(regionName)))) {
        continue;
      }
      return getReplicationBarrierResult(result);
    }
  }
}
 

/**
 * Extract the region encoded name from the region manifest
 */
static String getRegionNameFromManifest(final SnapshotRegionManifest manifest) {
  byte[] regionName = RegionInfo.createRegionName(
          ProtobufUtil.toTableName(manifest.getRegionInfo().getTableName()),
          manifest.getRegionInfo().getStartKey().toByteArray(),
          manifest.getRegionInfo().getRegionId(), true);
  return RegionInfo.encodeRegionName(regionName);
}
 

@Test
public void testParseName() throws IOException {
  final TableName tableName = TableName.valueOf(name.getMethodName());
  byte[] startKey = Bytes.toBytes("startKey");
  long regionId = System.currentTimeMillis();
  int replicaId = 42;

  // test without replicaId
  byte[] regionName = RegionInfo.createRegionName(tableName, startKey, regionId, false);

  byte[][] fields = RegionInfo.parseRegionName(regionName);
  assertArrayEquals(Bytes.toString(fields[0]),tableName.getName(), fields[0]);
  assertArrayEquals(Bytes.toString(fields[1]),startKey, fields[1]);
  assertArrayEquals(Bytes.toString(fields[2]), Bytes.toBytes(Long.toString(regionId)),fields[2]);
  assertEquals(3, fields.length);

  // test with replicaId
  regionName = RegionInfo.createRegionName(tableName, startKey, regionId,
    replicaId, false);

  fields = RegionInfo.parseRegionName(regionName);
  assertArrayEquals(Bytes.toString(fields[0]),tableName.getName(), fields[0]);
  assertArrayEquals(Bytes.toString(fields[1]),startKey, fields[1]);
  assertArrayEquals(Bytes.toString(fields[2]), Bytes.toBytes(Long.toString(regionId)),fields[2]);
  assertArrayEquals(Bytes.toString(fields[3]), Bytes.toBytes(
    String.format(RegionInfo.REPLICA_ID_FORMAT, replicaId)), fields[3]);
}
 

/**
 * @return the region name
 */
@XmlAttribute
public String getName() {
  byte [] tableNameAsBytes = Bytes.toBytes(this.table);
  TableName tableName = TableName.valueOf(tableNameAsBytes);
  byte [] nameAsBytes = RegionInfo.createRegionName(
    tableName, this.startKey, this.id, !tableName.isSystemTable());
  return Bytes.toString(nameAsBytes);
}