com.bigdata.btree.ReadOnlyIndex Maven / Gradle / Ivy
/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
[email protected]
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 Feb 16, 2007
*/
package com.bigdata.btree;
import java.util.Iterator;
import com.bigdata.btree.proc.AbstractKeyArrayIndexProcedureConstructor;
import com.bigdata.btree.proc.IResultHandler;
import com.bigdata.journal.IResourceManager;
import com.bigdata.mdi.IResourceMetadata;
import com.bigdata.service.Split;
import cutthecrap.utils.striterators.IFilter;
/**
* A fly-weight wrapper that does not permit write operations and reads through
* onto an underlying {@link IIndex}.
*
* Note: use this class sparingly. An index loaded from a historical commit
* point will always be read-only.
*
* @see {@link IResourceManager#getIndex(String, long)}
*
* @author Bryan Thompson
*/
public class ReadOnlyIndex extends DelegateIndex {
public ReadOnlyIndex(IIndex src) {
super(src);
}
/** {@link IndexMetadata} is cloned to disallow modification. */
@Override
final public IndexMetadata getIndexMetadata() {
return super.getIndexMetadata().clone();
}
/**
* {@link IResourceMetadata}[] is cloned to disallow modification (the
* {@link IResourceMetadata} instances in the array are all dynamically
* created so changes to them do not propagate back to the index).
*/
@Override
final public IResourceMetadata[] getResourceMetadata() {
return super.getResourceMetadata().clone();
}
/**
* Counter is read-only.
*/
@Override
final public ICounter getCounter() {
return new ReadOnlyCounter(super.getCounter());
}
/**
* Disabled.
*/
@Override
final public byte[] insert(byte[] key, byte[] value) {
throw new UnsupportedOperationException();
}
/**
* Disabled.
*/
@Override
final public byte[] remove(byte[] key) {
throw new UnsupportedOperationException();
}
/**
* {@link IRangeQuery#REMOVEALL} and {@link Iterator#remove()} are disabled.
*/
@Override
final public ITupleIterator rangeIterator(byte[] fromKey, byte[] toKey,
int capacity, int flags, IFilter filter) {
if ((flags & REMOVEALL) != 0) {
/*
* Note: Must be explicitly disabled!
*/
throw new UnsupportedOperationException();
}
/*
* Must explicitly disable Iterator#remove().
*/
return new ReadOnlyEntryIterator(super.rangeIterator(fromKey, toKey,
capacity, flags, filter));
}
// /**
// * Overridden to ensure that procedure is applied against read-only view and
// * not the {@link DelegateIndex}.
// */
// @Override
// final public T submit(final byte[] key, IIndexProcedure proc) {
//
// return proc.apply(this);
//
// }
//
// /**
// * Overridden to ensure that procedure is applied against read-only view and
// * not the {@link DelegateIndex}.
// */
// @Override
// @SuppressWarnings("unchecked")
// final public void submit(final byte[] fromKey, final byte[] toKey,
// final IIndexProcedure proc, final IResultHandler handler) {
//
// final Object result = proc.apply(this, handler);
//
// if (handler != null) {
//
// handler.aggregate(result, new Split(null,0,0));
//
// }
//
// }
/**
* Overridden to ensure that procedure is applied against read-only view and
* not the {@link DelegateIndex}.
*/
@SuppressWarnings("unchecked")
@Override
final public void submit(int fromIndex, int toIndex, byte[][] keys, byte[][] vals,
AbstractKeyArrayIndexProcedureConstructor ctor, IResultHandler aggregator) {
final Object result = ctor.newInstance(this,fromIndex, toIndex, keys, vals)
.apply(this);
if(aggregator != null) {
aggregator.aggregate(result, new Split(null,fromIndex,toIndex));
}
}
}