public final static int compareQualifiers(Cell left, byte[] right, int rOffset, int rLength) {
    if (left instanceof ByteBufferExtendedCell) {
      return ByteBufferUtils.compareTo(((ByteBufferExtendedCell) left).getQualifierByteBuffer(),
        ((ByteBufferExtendedCell) left).getQualifierPosition(), left.getQualifierLength(), right,
        rOffset, rLength);
    }
    return Bytes.compareTo(left.getQualifierArray(), left.getQualifierOffset(),
      left.getQualifierLength(), right, rOffset, rLength);
  }
Compares the cell's qualifier with the given byte[]
@param left    the cell for which the qualifier has to be compared
@param right   the byte[] having the qualifier
@param rOffset the offset of the qualifier
@param rLength the length of the qualifier
@return greater than 0 if left cell's qualifier is bigger than byte[], lesser than 0 if left
        cell's qualifier is lesser than byte[] and 0 otherwise
hbase-common/src/main/java/org/apache/hadoop/hbase/CellUtil.java