Java Get.getMaxVersions方法代碼示例

import org.apache.hadoop.hbase.client.Get; //導入方法依賴的package包/類
@Override
public Result[] get(List<Get> gets) throws IOException {
  byte[][] rows = new byte[gets.size()][];
  int maxVersions = 1;
  int count = 0;

  for(Get g:gets) {

    if ( count == 0 ) {
      maxVersions = g.getMaxVersions();
    } else if (g.getMaxVersions() != maxVersions) {
      LOG.warn("MaxVersions on Gets do not match, using the first in the list ("+maxVersions+")");
    }

    if (g.getFilter() != null) {
      LOG.warn("filters not supported on gets");
    }

    rows[count] = g.getRow();
    count ++;
  }

  String spec = buildMultiRowSpec(rows, maxVersions);

  return getResults(spec);
}
 

import org.apache.hadoop.hbase.client.Get; //導入方法依賴的package包/類
@Override
public void prePrepareTimeStampForDeleteVersion(
    ObserverContext<RegionCoprocessorEnvironment> ctx, Mutation delete, Cell cell,
    byte[] byteNow, Get get) throws IOException {
  // Nothing to do if we are not filtering by visibility
  if (!authorizationEnabled) {
    return;
  }

  CellVisibility cellVisibility = null;
  try {
    cellVisibility = delete.getCellVisibility();
  } catch (DeserializationException de) {
    throw new IOException("Invalid cell visibility specified " + delete, de);
  }
  // The check for checkForReservedVisibilityTagPresence happens in preBatchMutate happens.
  // It happens for every mutation and that would be enough.
  List<Tag> visibilityTags = new ArrayList<Tag>();
  if (cellVisibility != null) {
    String labelsExp = cellVisibility.getExpression();
    try {
      visibilityTags = this.visibilityLabelService.createVisibilityExpTags(labelsExp, false,
          false);
    } catch (InvalidLabelException e) {
      throw new IOException("Invalid cell visibility specified " + labelsExp, e);
    }
  }
  get.setFilter(new DeleteVersionVisibilityExpressionFilter(visibilityTags,
      VisibilityConstants.SORTED_ORDINAL_SERIALIZATION_FORMAT));
  List<Cell> result = ctx.getEnvironment().getRegion().get(get, false);

  if (result.size() < get.getMaxVersions()) {
    // Nothing to delete
    CellUtil.updateLatestStamp(cell, Long.MIN_VALUE);
    return;
  }
  if (result.size() > get.getMaxVersions()) {
    throw new RuntimeException("Unexpected size: " + result.size()
        + ". Results more than the max versions obtained.");
  }
  Cell getCell = result.get(get.getMaxVersions() - 1);
  CellUtil.setTimestamp(cell, getCell.getTimestamp());

  // We are bypassing here because in the HRegion.updateDeleteLatestVersionTimeStamp we would
  // update with the current timestamp after again doing a get. As the hook as already determined
  // the needed timestamp we need to bypass here.
  // TODO : See if HRegion.updateDeleteLatestVersionTimeStamp() could be
  // called only if the hook is not called.
  ctx.bypass();
}