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

private static <R, S, P extends Message, Q extends Message, T extends Message> void findMedian(
        CompletableFuture<R> future, AsyncTable<AdvancedScanResultConsumer> table,
        ColumnInterpreter<R, S, P, Q, T> ci, Scan scan, NavigableMap<byte[], S> sumByRegion) {
  double halfSum = ci.divideForAvg(sumByRegion.values().stream().reduce(ci::add).get(), 2L);
  S movingSum = null;
  byte[] startRow = null;
  for (Map.Entry<byte[], S> entry : sumByRegion.entrySet()) {
    startRow = entry.getKey();
    S newMovingSum = ci.add(movingSum, entry.getValue());
    if (ci.divideForAvg(newMovingSum, 1L) > halfSum) {
      break;
    }
    movingSum = newMovingSum;
  }
  if (startRow != null) {
    scan.withStartRow(startRow);
  }
  // we can not pass movingSum directly to an anonymous class as it is not final.
  S baseSum = movingSum;
  byte[] family = scan.getFamilies()[0];
  NavigableSet<byte[]> qualifiers = scan.getFamilyMap().get(family);
  byte[] weightQualifier = qualifiers.last();
  byte[] valueQualifier = qualifiers.first();
  table.scan(scan, new AdvancedScanResultConsumer() {
    private S sum = baseSum;

    private R value = null;

    @Override
    public void onNext(Result[] results, ScanController controller) {
      try {
        for (Result result : results) {
          Cell weightCell = result.getColumnLatestCell(family, weightQualifier);
          R weight = ci.getValue(family, weightQualifier, weightCell);
          sum = ci.add(sum, ci.castToReturnType(weight));
          if (ci.divideForAvg(sum, 1L) > halfSum) {
            if (value != null) {
              future.complete(value);
            } else {
              future.completeExceptionally(new NoSuchElementException());
            }
            controller.terminate();
            return;
          }
          Cell valueCell = result.getColumnLatestCell(family, valueQualifier);
          value = ci.getValue(family, valueQualifier, valueCell);
        }
      } catch (IOException e) {
        future.completeExceptionally(e);
        controller.terminate();
      }
    }

    @Override
    public void onError(Throwable error) {
      future.completeExceptionally(error);
    }

    @Override
    public void onComplete() {
      if (!future.isDone()) {
        // we should not reach here as the future should be completed in onNext.
        future.completeExceptionally(new NoSuchElementException());
      }
    }
  });
}
 

/**
 * Gives the maximum for a given combination of column qualifier and column
 * family, in the given row range as defined in the Scan object. In its
 * current implementation, it takes one column family and one column qualifier
 * (if provided). In case of null column qualifier, maximum value for the
 * entire column family will be returned.
 */
@Override
public void getMax(RpcController controller, AggregateRequest request,
        RpcCallback<AggregateResponse> done) {
  InternalScanner scanner = null;
  AggregateResponse response = null;
  T max = null;
  try {
    ColumnInterpreter<T, S, P, Q, R> ci = constructColumnInterpreterFromRequest(request);
    T temp;
    Scan scan = ProtobufUtil.toScan(request.getScan());
    scanner = env.getRegion().getScanner(scan);
    List<Cell> results = new ArrayList<>();
    byte[] colFamily = scan.getFamilies()[0];
    NavigableSet<byte[]> qualifiers = scan.getFamilyMap().get(colFamily);
    byte[] qualifier = null;
    if (qualifiers != null && !qualifiers.isEmpty()) {
      qualifier = qualifiers.pollFirst();
    }
    // qualifier can be null.
    boolean hasMoreRows = false;
    do {
      hasMoreRows = scanner.next(results);
      int listSize = results.size();
      for (int i = 0; i < listSize; i++) {
        temp = ci.getValue(colFamily, qualifier, results.get(i));
        max = (max == null || (temp != null && ci.compare(temp, max) > 0)) ? temp : max;
      }
      results.clear();
    } while (hasMoreRows);
    if (max != null) {
      AggregateResponse.Builder builder = AggregateResponse.newBuilder();
      builder.addFirstPart(ci.getProtoForCellType(max).toByteString());
      response = builder.build();
    }
  } catch (IOException e) {
    CoprocessorRpcUtils.setControllerException(controller, e);
  } finally {
    if (scanner != null) {
      try {
        scanner.close();
      } catch (IOException ignored) {}
    }
  }
  log.info("Maximum from this region is "
      + env.getRegion().getRegionInfo().getRegionNameAsString() + ": " + max);
  done.run(response);
}
 

/**
 * Gives the minimum for a given combination of column qualifier and column
 * family, in the given row range as defined in the Scan object. In its
 * current implementation, it takes one column family and one column qualifier
 * (if provided). In case of null column qualifier, minimum value for the
 * entire column family will be returned.
 */
@Override
public void getMin(RpcController controller, AggregateRequest request,
        RpcCallback<AggregateResponse> done) {
  AggregateResponse response = null;
  InternalScanner scanner = null;
  T min = null;
  try {
    ColumnInterpreter<T, S, P, Q, R> ci = constructColumnInterpreterFromRequest(request);
    T temp;
    Scan scan = ProtobufUtil.toScan(request.getScan());
    scanner = env.getRegion().getScanner(scan);
    List<Cell> results = new ArrayList<>();
    byte[] colFamily = scan.getFamilies()[0];
    NavigableSet<byte[]> qualifiers = scan.getFamilyMap().get(colFamily);
    byte[] qualifier = null;
    if (qualifiers != null && !qualifiers.isEmpty()) {
      qualifier = qualifiers.pollFirst();
    }
    boolean hasMoreRows = false;
    do {
      hasMoreRows = scanner.next(results);
      int listSize = results.size();
      for (int i = 0; i < listSize; i++) {
        temp = ci.getValue(colFamily, qualifier, results.get(i));
        min = (min == null || (temp != null && ci.compare(temp, min) < 0)) ? temp : min;
      }
      results.clear();
    } while (hasMoreRows);
    if (min != null) {
      response = AggregateResponse.newBuilder().addFirstPart(
        ci.getProtoForCellType(min).toByteString()).build();
    }
  } catch (IOException e) {
    CoprocessorRpcUtils.setControllerException(controller, e);
  } finally {
    if (scanner != null) {
      try {
        scanner.close();
      } catch (IOException ignored) {}
    }
  }
  log.info("Minimum from this region is "
      + env.getRegion().getRegionInfo().getRegionNameAsString() + ": " + min);
  done.run(response);
}
 

/**
 * Gives the sum for a given combination of column qualifier and column
 * family, in the given row range as defined in the Scan object. In its
 * current implementation, it takes one column family and one column qualifier
 * (if provided). In case of null column qualifier, sum for the entire column
 * family will be returned.
 */
@Override
public void getSum(RpcController controller, AggregateRequest request,
        RpcCallback<AggregateResponse> done) {
  AggregateResponse response = null;
  InternalScanner scanner = null;
  long sum = 0L;
  try {
    ColumnInterpreter<T, S, P, Q, R> ci = constructColumnInterpreterFromRequest(request);
    S sumVal = null;
    T temp;
    Scan scan = ProtobufUtil.toScan(request.getScan());
    scanner = env.getRegion().getScanner(scan);
    byte[] colFamily = scan.getFamilies()[0];
    NavigableSet<byte[]> qualifiers = scan.getFamilyMap().get(colFamily);
    byte[] qualifier = null;
    if (qualifiers != null && !qualifiers.isEmpty()) {
      qualifier = qualifiers.pollFirst();
    }
    List<Cell> results = new ArrayList<>();
    boolean hasMoreRows = false;
    do {
      hasMoreRows = scanner.next(results);
      int listSize = results.size();
      for (int i = 0; i < listSize; i++) {
        temp = ci.getValue(colFamily, qualifier, results.get(i));
        if (temp != null) {
          sumVal = ci.add(sumVal, ci.castToReturnType(temp));
        }
      }
      results.clear();
    } while (hasMoreRows);
    if (sumVal != null) {
      response = AggregateResponse.newBuilder().addFirstPart(
        ci.getProtoForPromotedType(sumVal).toByteString()).build();
    }
  } catch (IOException e) {
    CoprocessorRpcUtils.setControllerException(controller, e);
  } finally {
    if (scanner != null) {
      try {
        scanner.close();
      } catch (IOException ignored) {}
    }
  }
  log.debug("Sum from this region is "
      + env.getRegion().getRegionInfo().getRegionNameAsString() + ": " + sum);
  done.run(response);
}
 

/**
 * Gives the row count for the given column family and column qualifier, in
 * the given row range as defined in the Scan object.
 */
@Override
public void getRowNum(RpcController controller, AggregateRequest request,
        RpcCallback<AggregateResponse> done) {
  AggregateResponse response = null;
  long counter = 0L;
  List<Cell> results = new ArrayList<>();
  InternalScanner scanner = null;
  try {
    Scan scan = ProtobufUtil.toScan(request.getScan());
    byte[][] colFamilies = scan.getFamilies();
    byte[] colFamily = colFamilies != null ? colFamilies[0] : null;
    NavigableSet<byte[]> qualifiers = colFamilies != null ?
        scan.getFamilyMap().get(colFamily) : null;
    byte[] qualifier = null;
    if (qualifiers != null && !qualifiers.isEmpty()) {
      qualifier = qualifiers.pollFirst();
    }
    if (scan.getFilter() == null && qualifier == null) {
      scan.setFilter(new FirstKeyOnlyFilter());
    }
    scanner = env.getRegion().getScanner(scan);
    boolean hasMoreRows = false;
    do {
      hasMoreRows = scanner.next(results);
      if (results.size() > 0) {
        counter++;
      }
      results.clear();
    } while (hasMoreRows);
    ByteBuffer bb = ByteBuffer.allocate(8).putLong(counter);
    bb.rewind();
    response = AggregateResponse.newBuilder().addFirstPart(
        ByteString.copyFrom(bb)).build();
  } catch (IOException e) {
    CoprocessorRpcUtils.setControllerException(controller, e);
  } finally {
    if (scanner != null) {
      try {
        scanner.close();
      } catch (IOException ignored) {}
    }
  }
  log.info("Row counter from this region is "
      + env.getRegion().getRegionInfo().getRegionNameAsString() + ": " + counter);
  done.run(response);
}
 

/**
 * Gives a Pair with first object as Sum and second object as row count,
 * computed for a given combination of column qualifier and column family in
 * the given row range as defined in the Scan object. In its current
 * implementation, it takes one column family and one column qualifier (if
 * provided). In case of null column qualifier, an aggregate sum over all the
 * entire column family will be returned.
 * <p>
 * The average is computed in
 * AggregationClient#avg(byte[], ColumnInterpreter, Scan) by
 * processing results from all regions, so its "ok" to pass sum and a Long
 * type.
 */
@Override
public void getAvg(RpcController controller, AggregateRequest request,
        RpcCallback<AggregateResponse> done) {
  AggregateResponse response = null;
  InternalScanner scanner = null;
  try {
    ColumnInterpreter<T, S, P, Q, R> ci = constructColumnInterpreterFromRequest(request);
    S sumVal = null;
    Long rowCountVal = 0L;
    Scan scan = ProtobufUtil.toScan(request.getScan());
    scanner = env.getRegion().getScanner(scan);
    byte[] colFamily = scan.getFamilies()[0];
    NavigableSet<byte[]> qualifiers = scan.getFamilyMap().get(colFamily);
    byte[] qualifier = null;
    if (qualifiers != null && !qualifiers.isEmpty()) {
      qualifier = qualifiers.pollFirst();
    }
    List<Cell> results = new ArrayList<>();
    boolean hasMoreRows = false;

    do {
      results.clear();
      hasMoreRows = scanner.next(results);
      int listSize = results.size();
      for (int i = 0; i < listSize; i++) {
        sumVal = ci.add(sumVal, ci.castToReturnType(ci.getValue(colFamily,
            qualifier, results.get(i))));
      }
      rowCountVal++;
    } while (hasMoreRows);
    if (sumVal != null) {
      ByteString first = ci.getProtoForPromotedType(sumVal).toByteString();
      AggregateResponse.Builder pair = AggregateResponse.newBuilder();
      pair.addFirstPart(first);
      ByteBuffer bb = ByteBuffer.allocate(8).putLong(rowCountVal);
      bb.rewind();
      pair.setSecondPart(ByteString.copyFrom(bb));
      response = pair.build();
    }
  } catch (IOException e) {
    CoprocessorRpcUtils.setControllerException(controller, e);
  } finally {
    if (scanner != null) {
      try {
        scanner.close();
      } catch (IOException ignored) {}
    }
  }
  done.run(response);
}
 

/**
 * Gives a Pair with first object a List containing Sum and sum of squares,
 * and the second object as row count. It is computed for a given combination of
 * column qualifier and column family in the given row range as defined in the
 * Scan object. In its current implementation, it takes one column family and
 * one column qualifier (if provided). The idea is get the value of variance first:
 * the average of the squares less the square of the average a standard
 * deviation is square root of variance.
 */
@Override
public void getStd(RpcController controller, AggregateRequest request,
        RpcCallback<AggregateResponse> done) {
  InternalScanner scanner = null;
  AggregateResponse response = null;
  try {
    ColumnInterpreter<T, S, P, Q, R> ci = constructColumnInterpreterFromRequest(request);
    S sumVal = null, sumSqVal = null, tempVal = null;
    long rowCountVal = 0L;
    Scan scan = ProtobufUtil.toScan(request.getScan());
    scanner = env.getRegion().getScanner(scan);
    byte[] colFamily = scan.getFamilies()[0];
    NavigableSet<byte[]> qualifiers = scan.getFamilyMap().get(colFamily);
    byte[] qualifier = null;
    if (qualifiers != null && !qualifiers.isEmpty()) {
      qualifier = qualifiers.pollFirst();
    }
    List<Cell> results = new ArrayList<>();

    boolean hasMoreRows = false;

    do {
      tempVal = null;
      hasMoreRows = scanner.next(results);
      int listSize = results.size();
      for (int i = 0; i < listSize; i++) {
        tempVal = ci.add(tempVal, ci.castToReturnType(ci.getValue(colFamily,
            qualifier, results.get(i))));
      }
      results.clear();
      sumVal = ci.add(sumVal, tempVal);
      sumSqVal = ci.add(sumSqVal, ci.multiply(tempVal, tempVal));
      rowCountVal++;
    } while (hasMoreRows);
    if (sumVal != null) {
      ByteString first_sumVal = ci.getProtoForPromotedType(sumVal).toByteString();
      ByteString first_sumSqVal = ci.getProtoForPromotedType(sumSqVal).toByteString();
      AggregateResponse.Builder pair = AggregateResponse.newBuilder();
      pair.addFirstPart(first_sumVal);
      pair.addFirstPart(first_sumSqVal);
      ByteBuffer bb = ByteBuffer.allocate(8).putLong(rowCountVal);
      bb.rewind();
      pair.setSecondPart(ByteString.copyFrom(bb));
      response = pair.build();
    }
  } catch (IOException e) {
    CoprocessorRpcUtils.setControllerException(controller, e);
  } finally {
    if (scanner != null) {
      try {
        scanner.close();
      } catch (IOException ignored) {}
    }
  }
  done.run(response);
}
 

/**
 * Gives a List containing sum of values and sum of weights.
 * It is computed for the combination of column
 * family and column qualifier(s) in the given row range as defined in the
 * Scan object. In its current implementation, it takes one column family and
 * two column qualifiers. The first qualifier is for values column and
 * the second qualifier (optional) is for weight column.
 */
@Override
public void getMedian(RpcController controller, AggregateRequest request,
        RpcCallback<AggregateResponse> done) {
  AggregateResponse response = null;
  InternalScanner scanner = null;
  try {
    ColumnInterpreter<T, S, P, Q, R> ci = constructColumnInterpreterFromRequest(request);
    S sumVal = null, sumWeights = null, tempVal = null, tempWeight = null;
    Scan scan = ProtobufUtil.toScan(request.getScan());
    scanner = env.getRegion().getScanner(scan);
    byte[] colFamily = scan.getFamilies()[0];
    NavigableSet<byte[]> qualifiers = scan.getFamilyMap().get(colFamily);
    byte[] valQualifier = null, weightQualifier = null;
    if (qualifiers != null && !qualifiers.isEmpty()) {
      valQualifier = qualifiers.pollFirst();
      // if weighted median is requested, get qualifier for the weight column
      weightQualifier = qualifiers.pollLast();
    }
    List<Cell> results = new ArrayList<>();

    boolean hasMoreRows = false;

    do {
      tempVal = null;
      tempWeight = null;
      hasMoreRows = scanner.next(results);
      int listSize = results.size();
      for (int i = 0; i < listSize; i++) {
        Cell kv = results.get(i);
        tempVal = ci.add(tempVal, ci.castToReturnType(ci.getValue(colFamily,
            valQualifier, kv)));
        if (weightQualifier != null) {
          tempWeight = ci.add(tempWeight,
              ci.castToReturnType(ci.getValue(colFamily, weightQualifier, kv)));
        }
      }
      results.clear();
      sumVal = ci.add(sumVal, tempVal);
      sumWeights = ci.add(sumWeights, tempWeight);
    } while (hasMoreRows);
    ByteString first_sumVal = ci.getProtoForPromotedType(sumVal).toByteString();
    S s = sumWeights == null ? ci.castToReturnType(ci.getMinValue()) : sumWeights;
    ByteString first_sumWeights = ci.getProtoForPromotedType(s).toByteString();
    AggregateResponse.Builder pair = AggregateResponse.newBuilder();
    pair.addFirstPart(first_sumVal);
    pair.addFirstPart(first_sumWeights);
    response = pair.build();
  } catch (IOException e) {
    CoprocessorRpcUtils.setControllerException(controller, e);
  } finally {
    if (scanner != null) {
      try {
        scanner.close();
      } catch (IOException ignored) {}
    }
  }
  done.run(response);
}