Java Code Examples for org.apache.hadoop.hbase.client.Scan#setRowPrefixFilter()

/**
 * Returns a scanner for all namespace snapshot entries of the given namespace
 * @param namespace name of the namespace whose snapshot entries are to be scanned
 */
static Scan createScanForNamespaceSnapshotSizes(String namespace) {
  Scan s = new Scan();
  if (namespace == null || namespace.isEmpty()) {
    // Read all namespaces, just look at the row prefix
    s.setRowPrefixFilter(QUOTA_NAMESPACE_ROW_KEY_PREFIX);
  } else {
    // Fetch the exact row for the table
    byte[] rowkey = getNamespaceRowKey(namespace);
    // Fetch just this one row
    s.withStartRow(rowkey).withStopRow(rowkey, true);
  }

  // Just the usage family and only the snapshot size qualifiers
  return s.addFamily(QUOTA_FAMILY_USAGE)
      .setFilter(new ColumnPrefixFilter(QUOTA_SNAPSHOT_SIZE_QUALIFIER));
}
 

static Scan createScanForSpaceSnapshotSizes(TableName table) {
  Scan s = new Scan();
  if (null == table) {
    // Read all tables, just look at the row prefix
    s.setRowPrefixFilter(QUOTA_TABLE_ROW_KEY_PREFIX);
  } else {
    // Fetch the exact row for the table
    byte[] rowkey = getTableRowKey(table);
    // Fetch just this one row
    s.withStartRow(rowkey).withStopRow(rowkey, true);
  }

  // Just the usage family and only the snapshot size qualifiers
  return s.addFamily(QUOTA_FAMILY_USAGE).setFilter(
      new ColumnPrefixFilter(QUOTA_SNAPSHOT_SIZE_QUALIFIER));
}
 

private List<String> verifyRunStatusFromResultTable(Connection conn, Long scn, String indexTable, int totalRows, List<String> expectedStatus) throws SQLException, IOException {
    Table hIndexToolTable = conn.unwrap(PhoenixConnection.class).getQueryServices()
            .getTable(RESULT_TABLE_NAME_BYTES);
    Assert.assertEquals(totalRows, TestUtil.getRowCount(hIndexToolTable, false));
    List<String> output = new ArrayList<>();
    Scan s = new Scan();
    s.setRowPrefixFilter(Bytes.toBytes(String.format("%s%s%s", scn, ROW_KEY_SEPARATOR, indexTable)));
    ResultScanner rs = hIndexToolTable.getScanner(s);
    int count =0;
    for(Result r : rs) {
        Assert.assertTrue(r != null);
        List<Cell> cells = r.getColumnCells(RESULT_TABLE_COLUMN_FAMILY, INDEX_TOOL_RUN_STATUS_BYTES);
        Assert.assertEquals(cells.size(), 1);
        Assert.assertTrue(Bytes.toString(CellUtil.cloneRow(cells.get(0))).startsWith(String.valueOf(scn)));
        output.add(Bytes.toString(CellUtil.cloneValue(cells.get(0))));
        count++;
    }
    //for each region
    Assert.assertEquals(3, count);
    for(int i=0; i< count; i++) {
        Assert.assertEquals(expectedStatus.get(i), output.get(i));
    }
    return output;
}
 

private Scan getEdgeEndpointsScan(Vertex vertex, Direction direction, String... labels) {
    LOGGER.trace("Executing Scan, type: {}, id: {}", "key", vertex.id());

    final String key = Constants.CREATED_AT;
    byte[] startRow = serializeForRead(vertex, direction != Direction.BOTH ? direction : null, false,
            key, labels.length == 1 ? labels[0] : null, null);
    Scan scan = new Scan(startRow);
    scan.setRowPrefixFilter(startRow);
    scan.setFilter(applyEdgeLabelsRowFilter(vertex, direction, key, labels));
    return scan;
}
 

private Scan getEdgesScan(Vertex vertex, Direction direction, boolean isUnique, String key, String label, Object value) {
    LOGGER.trace("Executing Scan, type: {}, id: {}", "key-value", vertex.id());

    byte[] startRow = serializeForRead(vertex, direction, isUnique, key, label, value);
    Scan scan = new Scan(startRow);
    scan.setRowPrefixFilter(startRow);
    return scan;
}
 

@Override
protected Scan getInputScan(final HBaseGraph graph, final IndexMetadata index) {
    if (index.type() == ElementType.EDGE) {
        return new Scan();
    } else {
        // optimization for vertex index scans
        byte[] startRow = graph.getVertexIndexModel().serializeForRead(
                index.label(), index.isUnique(), index.propertyKey(), null);
        Scan scan = new Scan(startRow);
        scan.setRowPrefixFilter(startRow);
        return scan;
    }
}
 

/**
 * Creates a {@link Scan} which returns only {@link SpaceQuotaSnapshot} from the quota table for a
 * specific table.
 * @param tn Optionally, a table name to limit the scan's rowkey space. Can be null.
 */
public static Scan makeQuotaSnapshotScanForTable(TableName tn) {
  Scan s = new Scan();
  // Limit to "u:v" column
  s.addColumn(QUOTA_FAMILY_USAGE, QUOTA_QUALIFIER_POLICY);
  if (null == tn) {
    s.setRowPrefixFilter(QUOTA_TABLE_ROW_KEY_PREFIX);
  } else {
    byte[] row = getTableRowKey(tn);
    // Limit rowspace to the "t:" prefix
    s.withStartRow(row, true).withStopRow(row, true);
  }
  return s;
}
 

public boolean isValidLastVerifyTime(Long lastVerifyTime) throws Exception {
    try(Connection conn = getConnection(configuration)) {
        Table hIndexToolTable = conn.unwrap(PhoenixConnection.class).getQueryServices()
                .getTable(IndexVerificationResultRepository.RESULT_TABLE_NAME_BYTES);
        Scan s = new Scan();
        ConnectionQueryServices cqs = conn.unwrap(PhoenixConnection.class).getQueryServices();
        boolean isNamespaceMapped = SchemaUtil.isNamespaceMappingEnabled(null, cqs.getProps());
        s.setRowPrefixFilter(Bytes.toBytes(String.format("%s%s%s", lastVerifyTime,
                ROW_KEY_SEPARATOR,
                SchemaUtil.getPhysicalHBaseTableName(schemaName, indexTable, isNamespaceMapped))));
        ResultScanner rs = hIndexToolTable.getScanner(s);
        return rs.next() != null;
    }
}
 

private void deleteOneRowFromResultTable(Connection conn,  Long scn, String indexTable)
        throws SQLException, IOException {
    Table hIndexToolTable = conn.unwrap(PhoenixConnection.class).getQueryServices()
            .getTable(RESULT_TABLE_NAME_BYTES);
    Scan s = new Scan();
    s.setRowPrefixFilter(Bytes.toBytes(String.format("%s%s%s", scn, ROW_KEY_SEPARATOR, indexTable)));
    ResultScanner rs = hIndexToolTable.getScanner(s);
    hIndexToolTable.delete(new Delete(rs.next().getRow()));
}
 

private Scan getVertexIndexScan(String label, boolean isUnique, String key, Object value) {
    byte[] startRow = serializeForRead(label, isUnique, key, value);
    Scan scan = new Scan(startRow);
    scan.setRowPrefixFilter(startRow);
    return scan;
}