All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.apache.hadoop.hbase.regionserver.querymatcher.DeleteTracker Maven / Gradle / Ivy

There is a newer version: 3.0.0-beta-1
Show newest version
/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hbase.regionserver.querymatcher;

import org.apache.yetus.audience.InterfaceAudience;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellComparator;
import org.apache.hadoop.hbase.regionserver.ShipperListener;

/**
 * This interface is used for the tracking and enforcement of Deletes during the course of a Get or
 * Scan operation.
 * 

* This class is utilized through three methods: *

    *
  • {@link #add} when encountering a Delete
  • *
  • {@link #isDeleted} when checking if a Put Cell has been deleted
  • *
  • {@link #update} when reaching the end of a StoreFile
  • *
*/ @InterfaceAudience.Private public interface DeleteTracker extends ShipperListener { /** * Add the specified cell to the list of deletes to check against for this row operation. *

* This is called when a Delete is encountered in a StoreFile. * @param cell - the delete cell */ void add(Cell cell); /** * Check if the specified cell buffer has been deleted by a previously seen delete. * @param cell - current cell to check if deleted by a previously seen delete * @return deleteResult The result tells whether the Cell is deleted and why */ DeleteResult isDeleted(Cell cell); /** * @return true if there are no current delete, false otherwise */ boolean isEmpty(); /** * Called at the end of every StoreFile. *

* Many optimized implementations of Trackers will require an update at when the end of each * StoreFile is reached. */ void update(); /** * Called between rows. *

* This clears everything as if a new DeleteTracker was instantiated. */ void reset(); /** * Returns codes for delete result. The codes tell the ScanQueryMatcher whether the kv is deleted * and why. Based on the delete result, the ScanQueryMatcher will decide the next operation */ enum DeleteResult { FAMILY_DELETED, // The Cell is deleted by a delete family. FAMILY_VERSION_DELETED, // The Cell is deleted by a delete family version. COLUMN_DELETED, // The Cell is deleted by a delete column. VERSION_DELETED, // The Cell is deleted by a version delete. NOT_DELETED, VERSION_MASKED // The Cell is masked by max number of versions which is considered as // deleted in strong semantics of versions(See MvccTracker) } /** * Return the comparator passed to this delete tracker * @return the cell comparator */ CellComparator getCellComparator(); }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy