java/kudu-backup/src/main/scala/org/apache/kudu/backup/RowAction.java

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package org.apache.kudu.backup;

import java.util.Map;

import com.google.common.collect.ImmutableMap;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;

/**
 * A RowAction is used to represent the action associated with a backed up row.
 *
 * Currently UPSERT is the default action, while rows with the IS_DELETED virtual
 * column have an action of DELETE. This value is serialized as a byte in the
 * output data format to be as space efficient as possible.
 *
 * Given there are currently only 2 options, IS_DELETED or not, we could have used an
 * IS_DELETED boolean column in the output format, but this RowAction allows for greater
 * format flexibility to support INSERT or UPDATE in the future if we have full fidelity
 * and sparse row backups.
 *
 * See {@link RowIterator} for backup side usage and {@link KuduRestore} for restore
 * side usage.
 */
@InterfaceAudience.Private
@InterfaceStability.Unstable
public enum RowAction {

  UPSERT((byte) 0),
  DELETE((byte) 1);

  /** The byte value used to represent this RowAction */
  private final byte value;

  private static Map<Byte, RowAction> byteRowAction;
  static {
    byteRowAction = new ImmutableMap.Builder<Byte, RowAction>()
        .put(UPSERT.getValue(), UPSERT)
        .put(DELETE.getValue(), DELETE)
        .build();
  }

  RowAction(byte value) {
    this.value = value;
  }

  public byte getValue() {
    return value;
  }

  public static RowAction fromValue(Byte value) {
    return byteRowAction.get(value);
  }
}