Examples with ScanSpec org.hypertable.thriftgen.ScanSpec used on opensource projects

Example 1 with ScanSpec

use of org.hypertable.thriftgen.ScanSpec in project YCSB by brianfrankcooper.

the class HypertableClient method scan.

/**
   * Perform a range scan for a set of records in the database. Each field/value
   * pair from the result will be stored in a HashMap.
   *
   * @param table
   *          The name of the table
   * @param startkey
   *          The record key of the first record to read.
   * @param recordcount
   *          The number of records to read
   * @param fields
   *          The list of fields to read, or null for all of them
   * @param result
   *          A Vector of HashMaps, where each HashMap is a set field/value
   *          pairs for one record
   * @return Zero on success, a non-zero error code on error
   */
@Override
public Status scan(String table, String startkey, int recordcount, Set<String> fields, Vector<HashMap<String, ByteIterator>> result) {
    // SELECT _columnFamily:fields FROM table WHERE (ROW >= startkey)
    // LIMIT recordcount MAX_VERSIONS 1;
    ScanSpec spec = new ScanSpec();
    RowInterval elem = new RowInterval();
    elem.setStart_inclusive(true);
    elem.setStart_row(startkey);
    spec.addToRow_intervals(elem);
    if (null != fields) {
        for (String field : fields) {
            spec.addToColumns(columnFamily + ":" + field);
        }
    }
    spec.setVersions(1);
    spec.setRow_limit(recordcount);
    SerializedCellsReader reader = new SerializedCellsReader(null);
    try {
        long sc = connection.scanner_open(ns, table, spec);
        String lastRow = null;
        boolean eos = false;
        while (!eos) {
            reader.reset(connection.scanner_get_cells_serialized(sc));
            while (reader.next()) {
                String currentRow = new String(reader.get_row());
                if (!currentRow.equals(lastRow)) {
                    result.add(new HashMap<String, ByteIterator>());
                    lastRow = currentRow;
                }
                result.lastElement().put(new String(reader.get_column_qualifier()), new ByteArrayByteIterator(reader.get_value()));
            }
            eos = reader.eos();
            if (debug) {
                System.out.println("Number of rows retrieved so far: " + result.size());
            }
        }
        connection.scanner_close(sc);
    } catch (ClientException e) {
        if (debug) {
            System.err.println("Error doing scan: " + e.message);
        }
        return Status.ERROR;
    } catch (TException e) {
        if (debug) {
            System.err.println("Error doing scan");
        }
        return Status.ERROR;
    }
    return Status.OK;
}