Java Scan.getMaxVersions方法代码示例

import org.apache.hadoop.hbase.client.Scan; //导入方法依赖的package包/类
/**
 * Construct a QueryMatcher for a scan
 * @param scan
 * @param scanInfo The store's immutable scan info
 * @param columns
 * @param scanType Type of the scan
 * @param earliestPutTs Earliest put seen in any of the store files.
 * @param oldestUnexpiredTS the oldest timestamp we are interested in,
 *  based on TTL
 * @param regionCoprocessorHost 
 * @throws IOException 
 */
public ScanQueryMatcher(Scan scan, ScanInfo scanInfo, NavigableSet<byte[]> columns,
    ScanType scanType, long readPointToUse, long earliestPutTs, long oldestUnexpiredTS,
    long now, RegionCoprocessorHost regionCoprocessorHost) throws IOException {
  TimeRange timeRange = scan.getColumnFamilyTimeRange().get(scanInfo.getFamily());
  if (timeRange == null) {
    this.tr = scan.getTimeRange();
  } else {
    this.tr = timeRange;
  }
  this.rowComparator = scanInfo.getComparator();
  this.regionCoprocessorHost = regionCoprocessorHost;
  this.deletes =  instantiateDeleteTracker();
  this.stopRow = scan.getStopRow();
  this.startKey = KeyValueUtil.createFirstDeleteFamilyOnRow(scan.getStartRow(),
      scanInfo.getFamily());
  this.filter = scan.getFilter();
  this.earliestPutTs = earliestPutTs;
  this.oldestUnexpiredTS = oldestUnexpiredTS;
  this.now = now;

  this.maxReadPointToTrackVersions = readPointToUse;
  this.timeToPurgeDeletes = scanInfo.getTimeToPurgeDeletes();
  this.ttl = oldestUnexpiredTS;

  /* how to deal with deletes */
  this.isUserScan = scanType == ScanType.USER_SCAN;
  // keep deleted cells: if compaction or raw scan
  this.keepDeletedCells = scan.isRaw() ? KeepDeletedCells.TRUE :
    isUserScan ? KeepDeletedCells.FALSE : scanInfo.getKeepDeletedCells();
  // retain deletes: if minor compaction or raw scanisDone
  this.retainDeletesInOutput = scanType == ScanType.COMPACT_RETAIN_DELETES || scan.isRaw();
  // seePastDeleteMarker: user initiated scans
  this.seePastDeleteMarkers =
      scanInfo.getKeepDeletedCells() != KeepDeletedCells.FALSE && isUserScan;

  int maxVersions =
      scan.isRaw() ? scan.getMaxVersions() : Math.min(scan.getMaxVersions(),
        scanInfo.getMaxVersions());

  // Single branch to deal with two types of reads (columns vs all in family)
  if (columns == null || columns.size() == 0) {
    // there is always a null column in the wildcard column query.
    hasNullColumn = true;

    // use a specialized scan for wildcard column tracker.
    this.columns = new ScanWildcardColumnTracker(
        scanInfo.getMinVersions(), maxVersions, oldestUnexpiredTS);
  } else {
    // whether there is null column in the explicit column query
    hasNullColumn = (columns.first().length == 0);

    // We can share the ExplicitColumnTracker, diff is we reset
    // between rows, not between storefiles.
    this.columns = new ExplicitColumnTracker(columns, scanInfo.getMinVersions(), maxVersions,
        oldestUnexpiredTS);
  }
  this.isReversed = scan.isReversed();
}
 

import org.apache.hadoop.hbase.client.Scan; //导入方法依赖的package包/类
/**
 * @param scan the scan specification
 * @throws Exception 
 */
public static ScannerModel fromScan(Scan scan) throws Exception {
  ScannerModel model = new ScannerModel();
  model.setStartRow(scan.getStartRow());
  model.setEndRow(scan.getStopRow());
  Map<byte [], NavigableSet<byte []>> families = scan.getFamilyMap();
  if (families != null) {
    for (Map.Entry<byte [], NavigableSet<byte []>> entry : families.entrySet()) {
      if (entry.getValue() != null) {
        for (byte[] qualifier: entry.getValue()) {
          model.addColumn(Bytes.add(entry.getKey(), COLUMN_DIVIDER, qualifier));
        }
      } else {
        model.addColumn(entry.getKey());
      }
    }
  }
  model.setStartTime(scan.getTimeRange().getMin());
  model.setEndTime(scan.getTimeRange().getMax());
  int caching = scan.getCaching();
  if (caching > 0) {
    model.setCaching(caching);
  }
  int batch = scan.getBatch();
  if (batch > 0) {
    model.setBatch(batch);
  }
  int maxVersions = scan.getMaxVersions();
  if (maxVersions > 0) {
    model.setMaxVersions(maxVersions);
  }
  Filter filter = scan.getFilter();
  if (filter != null) {
    model.setFilter(stringifyFilter(filter));
  }
  // Add the visbility labels if found in the attributes
  Authorizations authorizations = scan.getAuthorizations();
  if (authorizations != null) {
    List<String> labels = authorizations.getLabels();
    for (String label : labels) {
      model.addLabel(label);
    }
  }
  return model;
}