/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Dec 2, 2008
*/
package com.bigdata.resources;
import java.util.UUID;
import com.bigdata.btree.BTree;
/**
* Abstract base class for tasks responsible for the atomic update of the view
* of an index partition.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public abstract class AbstractAtomicUpdateTask<T> extends
AbstractResourceManagerTask<T> {
/**
*
* @param resourceManager
* @param timestamp
* @param resource
*/
public AbstractAtomicUpdateTask(
final ResourceManager resourceManager,
final long timestamp,
final String[] resource
) {
super(resourceManager, timestamp, resource);
}
/**
* @param resourceManager
* @param timestamp
* @param resource
* @param indexUUID
* The {@link UUID} associated with the scale-out index.
*/
public AbstractAtomicUpdateTask(
final ResourceManager resourceManager,
final long timestamp,
final String resource) {
super(resourceManager, timestamp, resource);
}
/**
* Verifies that the view is a view of the expected scale-out index.
* <p>
* This is used to detect drop/add sequences where a scale-out index exists
* with the same name but a different index {@link UUID}. Atomic update
* tasks check for this and disallow the update in order to prevent
* incorporation of the old index state into the new index.
*
* @param expectedIndexUUID
* The expected index UUID.
* @param view
* {@link BTree} whose view will be re-defined (must be part of
* the same scale-out index).
*
* @throws IllegalStateException
* if the index {@link UUID} does not agree.
*
* FIXME make sure that everyone tests this.
*/
protected void assertSameIndex(final UUID expectedIndexUUID,
final BTree view) {
if (!expectedIndexUUID.equals(view.getIndexMetadata().getIndexUUID())) {
/*
* This can happen if you drop/add a scale-out index during overflow
* processing. The new index will have a new UUID. We check this to
* prevent merging in data from the old index.
*/
throw new RuntimeException(
"Different UUID: presuming drop/add of index: name="
+ getOnlyResource());
}
}
}