/*
* 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.cassandra.index.transactions;
import org.apache.cassandra.db.rows.Row;
/**
* Performs garbage collection of stale index entries during a regular compaction.
*
* A CompactionTransaction is concerned with cleaning up stale index entries.
* When multiple versions of a row are compacted, the CompactionTransaction is
* notified of the versions being merged, which it diffs against the merge result.
*
* Instances are currently scoped to a single row within a partition, but this could be improved to batch process
* multiple rows within a single partition.
*/
public interface CompactionTransaction extends IndexTransaction
{
void onRowMerge(Row merged, Row...versions);
CompactionTransaction NO_OP = new CompactionTransaction()
{
public void start(){}
public void onRowMerge(Row merged, Row...versions){}
public void commit(){}
};
}