TransactionFilters.java

/*
 * Copyright © 2016 Cask Data, Inc.
 *
 * Licensed 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 co.cask.tephra.hbase10.coprocessor;

import co.cask.tephra.Transaction;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.regionserver.ScanType;

import java.util.Map;
import javax.annotation.Nullable;

/**
 * Factory class for providing {@link Filter} instances.
 */
public class TransactionFilters {
  /**
   * Creates a new {@link org.apache.hadoop.hbase.filter.Filter} for returning data only from visible transactions.
   *
   * @param tx the current transaction to apply.  Only data visible to this transaction will be returned.
   * @param ttlByFamily map of time-to-live (TTL) (in milliseconds) by column family name
   * @param allowEmptyValues if {@code true} cells with empty {@code byte[]} values will be returned, if {@code false}
   *                         these will be interpreted as "delete" markers and the column will be filtered out
   * @param scanType the type of scan operation being performed
   */
  public static Filter getVisibilityFilter(Transaction tx, Map<byte[], Long> ttlByFamily, boolean allowEmptyValues,
                                           ScanType scanType) {
    return new CellSkipFilter(new TransactionVisibilityFilter(tx, ttlByFamily, allowEmptyValues, scanType, null));
  }

  /**
   * Creates a new {@link org.apache.hadoop.hbase.filter.Filter} for returning data only from visible transactions.
   *
   * @param tx the current transaction to apply.  Only data visible to this transaction will be returned.
   * @param ttlByFamily map of time-to-live (TTL) (in milliseconds) by column family name
   * @param allowEmptyValues if {@code true} cells with empty {@code byte[]} values will be returned, if {@code false}
   *                         these will be interpreted as "delete" markers and the column will be filtered out
   * @param scanType the type of scan operation being performed
   * @param cellFilter if non-null, this filter will be applied to all cells visible to the current transaction, by
   *                   calling {@link Filter#filterKeyValue(org.apache.hadoop.hbase.Cell)}.  If null, then
   *                   {@link Filter.ReturnCode#INCLUDE_AND_NEXT_COL} will be returned instead.
   */
  public static Filter getVisibilityFilter(Transaction tx, Map<byte[], Long> ttlByFamily, boolean allowEmptyValues,
                                           ScanType scanType, @Nullable Filter cellFilter) {
    return new CellSkipFilter(new TransactionVisibilityFilter(tx, ttlByFamily, allowEmptyValues, scanType, cellFilter));
  }
}