[HBASE-17734] Guard against possibly copying the qualifier in the ScanDeleteTracker

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Hadoop Flags: Reviewed
• Assignee: Chia-Ping Tsai
• Reporter: Chia-Ping Tsai
• Created: 04/Mar/17 22:13
• Updated: 07/Mar/17 02:10
• Resolved: 07/Mar/17 02:01

Description

If the input cell is ByteBufferKeyValue, the ByteBufferKeyValue#getQualifierArray will copy the qualifier bytes.
ScanDeleteTracker should keep the cell rather than qualifier array.

  public void add(Cell cell) {
  long timestamp = cell.getTimestamp();
  byte type = cell.getTypeByte();
  if (!hasFamilyStamp || timestamp > familyStamp) {
  if (type == KeyValue.Type.DeleteFamily.getCode()) {
  hasFamilyStamp = true;
  familyStamp = timestamp;
  return;
  } else if (type == KeyValue.Type.DeleteFamilyVersion.getCode()) {
  familyVersionStamps.add(timestamp);
  return;
  }

  if (deleteBuffer != null && type < deleteType) {
  // same column, so ignore less specific delete
  if (CellUtil.matchingQualifier(cell, deleteBuffer, deleteOffset, deleteLength)) {
  return;
  }
  }
  // new column, or more general delete type
  deleteBuffer = cell.getQualifierArray();
  deleteOffset = cell.getQualifierOffset();
  deleteLength = cell.getQualifierLength();
  deleteType = type;
  deleteTimestamp = timestamp;
  }
  // missing else is never called.
  }