public static Scan mergeRangeScans(List<Scan> rangeScans) {
  List<RowRange> ranges = Lists.newArrayList();
  
  for (Scan rangeScan : rangeScans) {
    byte[] startRow = rangeScan.getStartRow();
    byte[] stopRow = rangeScan.getStopRow();
    
    ranges.add(new RowRange(startRow, true, stopRow, false));
  }
  
  Scan mergedScan = new Scan();
  try {
    mergedScan.setFilter(new MultiRowRangeFilter(ranges));
  } catch (IOException e) {
    throw new RuntimeException(e);
  }
  
  return mergedScan;
}
 

@Test
public void testMergePrefixScans() throws IOException {
  List<Scan> scans = Lists.newArrayList();
  
  byte[] startRow1 = Bytes.toBytes("hello");
  byte[] stopRow1 = Bytes.toBytes("hellp");
  Scan scan1 = new Scan(startRow1, stopRow1);
  scans.add(scan1);
  
  byte[] startRow2 = Bytes.toBytes("world");
  byte[] stopRow2 = Bytes.toBytes("worle");
  Scan scan2 = new Scan(startRow2, stopRow2);
  scans.add(scan2);
  
  Scan merged = HBaseUtils.mergeRangeScans(scans);
  
  assertEquals(MultiRowRangeFilter.class, merged.getFilter().getClass());
  MultiRowRangeFilter mergedFilter = (MultiRowRangeFilter)merged.getFilter();
  List<RowRange> ranges = mergedFilter.getRowRanges();
  assertEquals(2, ranges.size());
  assertTrue(ranges.get(0).getStartRow().equals(startRow1));
  assertTrue(ranges.get(0).getStopRow().equals(stopRow1));
  assertTrue(ranges.get(1).getStartRow().equals(startRow2));
  assertTrue(ranges.get(1).getStopRow().equals(stopRow2));
}
 

public static void main(String[] args) throws Exception {
    if (args.length < 1) {
        throw new Exception("Table name not specified.");
    }
    Configuration conf = HBaseConfiguration.create();
    HTable table = new HTable(conf, args[0]);

    Scan scan = new Scan();
    List<RowKeyRange> ranges = new ArrayList<RowKeyRange>();
    ranges.add(new RowKeyRange(Bytes.toBytes("001"), Bytes.toBytes("002")));
    ranges.add(new RowKeyRange(Bytes.toBytes("003"), Bytes.toBytes("004")));
    ranges.add(new RowKeyRange(Bytes.toBytes("005"), Bytes.toBytes("006")));
    Filter filter = new MultiRowRangeFilter(ranges);
    scan.setFilter(filter);
    int count = 0;
    ResultScanner scanner = table.getScanner(scan);
    Result r = scanner.next();
    while (r != null) {
        count++;
        r = scanner.next();
    }
    System.out
            .println("++ Scanning finished with count : " + count + " ++");
    scanner.close();

}
 

private static List<MultiRowRangeFilter.RowRange> parseRowRangeParameter(String arg) {
  final List<String> rangesSplit = Splitter.on(";").splitToList(arg);
  final List<MultiRowRangeFilter.RowRange> rangeList = new ArrayList<>();
  for (String range : rangesSplit) {
    if(range!=null && !range.isEmpty()) {
      List<String> startEnd = Splitter.on(",").splitToList(range);
      if (startEnd.size() != 2 || startEnd.get(1).contains(",")) {
        throw new IllegalArgumentException("Wrong range specification: " + range);
      }
      String startKey = startEnd.get(0);
      String endKey = startEnd.get(1);
      rangeList.add(new MultiRowRangeFilter.RowRange(Bytes.toBytesBinary(startKey),
          true, Bytes.toBytesBinary(endKey), false));
    }
  }
  return rangeList;
}
 

protected Scan getMultiScanner(final FilterList filterList) {
  // Single scan w/ multiple ranges
  final Scan multiScanner = scanProvider.get();
  final List<ByteArrayRange> ranges = readerParams.getQueryRanges().getCompositeQueryRanges();

  final MultiRowRangeFilter filter = operations.getMultiRowRangeFilter(ranges);
  if (filter != null) {
    filterList.addFilter(filter);

    final List<RowRange> rowRanges = filter.getRowRanges();
    multiScanner.setStartRow(rowRanges.get(0).getStartRow());

    final RowRange stopRowRange = rowRanges.get(rowRanges.size() - 1);
    byte[] stopRowExclusive;
    if (stopRowRange.isStopRowInclusive()) {
      // because the end is always exclusive, to make an inclusive
      // stop row into exlusive all we need to do is add a traling 0
      stopRowExclusive = HBaseUtils.getInclusiveEndKey(stopRowRange.getStopRow());
    } else {
      stopRowExclusive = stopRowRange.getStopRow();
    }
    multiScanner.setStopRow(stopRowExclusive);
  }
  return multiScanner;
}
 

public static void readRowRanges(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests. After completing all of your requests, call
  // the "close" method on the client to safely clean up any remaining background resources.
  try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
    Table table = connection.getTable(TableName.valueOf(tableId));
    List<RowRange> ranges = new ArrayList<>();

    ranges.add(
        new RowRange(
            Bytes.toBytes("phone#4c410523#20190501"),
            true,
            Bytes.toBytes("phone#4c410523#20190601"),
            false));
    ranges.add(
        new RowRange(
            Bytes.toBytes("phone#5c10102#20190501"),
            true,
            Bytes.toBytes("phone#5c10102#20190601"),
            false));
    Filter filter = new MultiRowRangeFilter(ranges);
    Scan scan = new Scan().setFilter(filter);

    ResultScanner rows = table.getScanner(scan);

    for (Result row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}
 

/**
 * Sets filter {@link FilterBase} to the {@link Scan} instance.
 * If provided rowRangeList contains more than one element,
 * method sets filter which is instance of {@link MultiRowRangeFilter}.
 * Otherwise, method sets filter which is instance of {@link FirstKeyOnlyFilter}.
 * If rowRangeList contains exactly one element, startRow and stopRow are set to the scan.
 * @param scan
 * @param rowRangeList
 */
private static void setScanFilter(Scan scan, List<MultiRowRangeFilter.RowRange> rowRangeList) {
  final int size = rowRangeList == null ? 0 : rowRangeList.size();
  if (size <= 1) {
    scan.setFilter(new FirstKeyOnlyFilter());
  }
  if (size == 1) {
    MultiRowRangeFilter.RowRange range = rowRangeList.get(0);
    scan.withStartRow(range.getStartRow()); //inclusive
    scan.withStopRow(range.getStopRow());   //exclusive
  } else if (size > 1) {
    scan.setFilter(new MultiRowRangeFilter(rowRangeList));
  }
}
 

public MultiRowRangeFilter getMultiRowRangeFilter(final List<ByteArrayRange> ranges) {
  // create the multi-row filter
  final List<RowRange> rowRanges = new ArrayList<>();
  if ((ranges == null) || ranges.isEmpty()) {
    rowRanges.add(
        new RowRange(HConstants.EMPTY_BYTE_ARRAY, true, HConstants.EMPTY_BYTE_ARRAY, false));
  } else {
    for (final ByteArrayRange range : ranges) {
      if (range.getStart() != null) {
        final byte[] startRow = range.getStart();
        byte[] stopRow;
        if (!range.isSingleValue()) {
          stopRow = range.getEndAsNextPrefix();
        } else {
          stopRow = ByteArrayUtils.getNextPrefix(range.getStart());
        }

        final RowRange rowRange = new RowRange(startRow, true, stopRow, false);

        rowRanges.add(rowRange);
      }
    }
  }

  // Create the multi-range filter
  try {
    return new MultiRowRangeFilter(rowRanges);
  } catch (final IOException e) {
    LOGGER.error("Error creating range filter.", e);
  }
  return null;
}
 

@Override
public int run(CommandLine cmd) throws Exception {
    String source = cmd.getOptionValue('s');
    String target = cmd.getOptionValue('t');
    String targetGraph = cmd.getOptionValue('g');
    String graphContext = cmd.getOptionValue('c');
    String thresh = cmd.getOptionValue('r');
    TableMapReduceUtil.addDependencyJars(getConf(),
        HalyardExport.class,
        NTriplesUtil.class,
        Rio.class,
        AbstractRDFHandler.class,
        RDFFormat.class,
        RDFParser.class,
        HTable.class,
        HBaseConfiguration.class,
        AuthenticationProtos.class,
        Trace.class,
        Gauge.class);
    HBaseConfiguration.addHbaseResources(getConf());
    Job job = Job.getInstance(getConf(), "HalyardStats " + source + (target == null ? " update" : " -> " + target));
    job.getConfiguration().set(SOURCE, source);
    if (target != null) job.getConfiguration().set(TARGET, target);
    if (targetGraph != null) job.getConfiguration().set(TARGET_GRAPH, targetGraph);
    if (graphContext != null) job.getConfiguration().set(GRAPH_CONTEXT, graphContext);
    if (thresh != null) job.getConfiguration().setLong(THRESHOLD, Long.parseLong(thresh));
    job.setJarByClass(HalyardStats.class);
    TableMapReduceUtil.initCredentials(job);

    Scan scan = HalyardTableUtils.scan(null, null);
    if (graphContext != null) { //restricting stats to scan given graph context only
        List<RowRange> ranges = new ArrayList<>();
        byte[] gcHash = HalyardTableUtils.hashKey(SimpleValueFactory.getInstance().createIRI(graphContext));
        ranges.add(rowRange(HalyardTableUtils.CSPO_PREFIX, gcHash));
        ranges.add(rowRange(HalyardTableUtils.CPOS_PREFIX, gcHash));
        ranges.add(rowRange(HalyardTableUtils.COSP_PREFIX, gcHash));
        if (target == null) { //add stats context to the scanned row ranges (when in update mode) to delete the related stats during MapReduce
            ranges.add(rowRange(HalyardTableUtils.CSPO_PREFIX, HalyardTableUtils.hashKey(targetGraph == null ? HALYARD.STATS_GRAPH_CONTEXT : SimpleValueFactory.getInstance().createIRI(targetGraph))));
        }
        scan.setFilter(new MultiRowRangeFilter(ranges));
    }
    TableMapReduceUtil.initTableMapperJob(
        source,
        scan,
        StatsMapper.class,
        ImmutableBytesWritable.class,
        LongWritable.class,
        job);
    job.setPartitionerClass(StatsPartitioner.class);
    job.setReducerClass(StatsReducer.class);
    job.setOutputFormatClass(NullOutputFormat.class);
    if (job.waitForCompletion(true)) {
        LOG.info("Stats Generation Completed..");
        return 0;
    }
    return -1;
}
 

@ProcessElement
public void processElement(PipelineOptions po) {
  // Determine which column will be drawn based on runtime of job.
  long timestampDiff = System.currentTimeMillis() - START_TIME;
  long minutes = (timestampDiff / 1000) / 60;
  int timeOffsetIndex = Math.toIntExact(minutes / KEY_VIZ_WINDOW_MINUTES);

  ReadDataOptions options = po.as(ReadDataOptions.class);
  long count = 0;

  List<RowRange> ranges = getRangesForTimeIndex(timeOffsetIndex, getNumRows(options));
  if (ranges.size() == 0) {
    return;
  }

  try {
    // Scan with a filter that will only return the first key from each row. This filter is used
    // to more efficiently perform row count operations.
    Filter rangeFilters = new MultiRowRangeFilter(ranges);
    FilterList firstKeyFilterWithRanges = new FilterList(
        rangeFilters,
        new FirstKeyOnlyFilter(),
        new KeyOnlyFilter());
    Scan scan =
        new Scan()
            .addFamily(Bytes.toBytes(COLUMN_FAMILY))
            .setFilter(firstKeyFilterWithRanges);

    Table table = getConnection().getTable(TableName.valueOf(options.getBigtableTableId()));
    ResultScanner imageData = table.getScanner(scan);

    // Iterate over stream of rows to count them.
    for (Result row : imageData) {
      count++;
    }
  } catch (Exception e) {
    System.out.println("Error reading.");
    e.printStackTrace();
  }
  System.out.printf("got %d rows\n", count);
}
 

/**
 * Sets up the actual job.
 *
 * @param conf  The current configuration.
 * @param args  The command line parameters.
 * @return The newly created job.
 * @throws IOException When setting up the job fails.
 * @deprecated as of release 2.3.0. Will be removed on 4.0.0. Please use main method instead.
 */
@Deprecated
public static Job createSubmittableJob(Configuration conf, String[] args)
  throws IOException {
  String tableName = args[0];
  List<MultiRowRangeFilter.RowRange> rowRangeList = null;
  long startTime = 0;
  long endTime = 0;

  StringBuilder sb = new StringBuilder();

  final String rangeSwitch = "--range=";
  final String startTimeArgKey = "--starttime=";
  final String endTimeArgKey = "--endtime=";
  final String expectedCountArg = "--expected-count=";

  // First argument is table name, starting from second
  for (int i = 1; i < args.length; i++) {
    if (args[i].startsWith(rangeSwitch)) {
      try {
        rowRangeList = parseRowRangeParameter(
          args[i].substring(args[1].indexOf(rangeSwitch)+rangeSwitch.length()));
      } catch (IllegalArgumentException e) {
        return null;
      }
      continue;
    }
    if (args[i].startsWith(startTimeArgKey)) {
      startTime = Long.parseLong(args[i].substring(startTimeArgKey.length()));
      continue;
    }
    if (args[i].startsWith(endTimeArgKey)) {
      endTime = Long.parseLong(args[i].substring(endTimeArgKey.length()));
      continue;
    }
    if (args[i].startsWith(expectedCountArg)) {
      conf.setLong(EXPECTED_COUNT_KEY,
        Long.parseLong(args[i].substring(expectedCountArg.length())));
      continue;
    }
    // if no switch, assume column names
    sb.append(args[i]);
    sb.append(" ");
  }
  if (endTime < startTime) {
    printUsage("--endtime=" + endTime + " needs to be greater than --starttime=" + startTime);
    return null;
  }

  Job job = Job.getInstance(conf, conf.get(JOB_NAME_CONF_KEY, NAME + "_" + tableName));
  job.setJarByClass(RowCounter.class);
  Scan scan = new Scan();
  scan.setCacheBlocks(false);
  setScanFilter(scan, rowRangeList);
  if (sb.length() > 0) {
    for (String columnName : sb.toString().trim().split(" ")) {
      String family = StringUtils.substringBefore(columnName, ":");
      String qualifier = StringUtils.substringAfter(columnName, ":");

      if (StringUtils.isBlank(qualifier)) {
        scan.addFamily(Bytes.toBytes(family));
      }
      else {
        scan.addColumn(Bytes.toBytes(family), Bytes.toBytes(qualifier));
      }
    }
  }
  scan.setTimeRange(startTime, endTime == 0 ? HConstants.LATEST_TIMESTAMP : endTime);
  job.setOutputFormatClass(NullOutputFormat.class);
  TableMapReduceUtil.initTableMapperJob(tableName, scan,
    RowCounterMapper.class, ImmutableBytesWritable.class, Result.class, job);
  job.setNumReduceTasks(0);
  return job;
}