Class KeyValue

src/KeyValue.java:51–476

A "cell" in an HBase table. This represents one unit of HBase data, one "record". A note byte arrays This class will never copy any byte[] that's given to it, neither will it create a copy before returning one to you. Changing a byte array get from or pass to th

 * one instance may also unexpectedly affect others.
 */
public final class KeyValue implements Comparable<KeyValue> {

  /**
   * Timestamp value to let the server set the timestamp at processing time.
   * When this value is used as a timestamp on a {@code KeyValue}, the server
   * will substitute a real timestamp at the time it processes it.  HBase uses
   * current UNIX time in milliseconds.
   */
  public static final long TIMESTAMP_NOW = Long.MAX_VALUE;

  //private static final Logger LOG = LoggerFactory.getLogger(KeyValue.class);

  private final byte[] key;     // Max length: Short.MAX_VALUE = 32768
  private final byte[] family;  // Max length: Byte.MAX_VALUE  =   128
  private final byte[] qualifier;
  private final byte[] value;
  private final long timestamp;
  //private final byte type;  // Not needed for us ATM.

  // Note: type can be one of:
  //   -  4  0b00000100  Put
  static final byte PUT = 4;
  //   -  8  0b00001000  Delete        (delete the specified version of a cell)
  static final byte DELETE = 8;
  //   - 12  0b00001100  DeleteColumn  (delete all previous versions of a cell)
  static final byte DELETE_COLUMN = 12;
  //   - 14  0b01110010  DeleteFamily  (delete all cells within a family)
  static final byte DELETE_FAMILY = 14;
  // (Not sure how those have been assigned...  Randomly maybe?)

  /**
   * Constructor.
   * @param key The row key.  Length must fit in 16 bits.
   * @param family The column family.  Length must fit in 8 bits.
   * @param qualifier The column qualifier.
   * @param timestamp Timestamp on the value.  This timestamp can be set to
   * guarantee ordering of values or operations.  It is strongly advised to
   * use a UNIX timestamp in milliseconds, e.g. from a source such as
   * {@link System#currentTimeMillis}.  This value must be strictly positive.
   * @param value The value, the contents of the cell.
   * @throws IllegalArgumentException if any argument is invalid (e.g. array
   * size is too long) or if the timestamp is negative.
   * @since 1.2
   */
  public KeyValue(final byte[] key,
                  final byte[] family, final byte[] qualifier,
                  final long timestamp,
                  //final byte type,
                  final byte[] value) {
    checkKey(key);
    checkFamily(family);
    checkQualifier(qualifier);
    checkTimestamp(timestamp);
    checkValue(value);
    this.key = key;
    this.family = family;
    this.qualifier = qualifier;
    this.value = value;