/**
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 Aug 25, 2010
*/
package com.bigdata.bop.bset;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;
import com.bigdata.bop.BOp;
import com.bigdata.bop.BOpContext;
import com.bigdata.bop.BOpUtility;
import com.bigdata.bop.IBindingSet;
import com.bigdata.bop.IConstraint;
import com.bigdata.bop.IVariable;
import com.bigdata.bop.NV;
import com.bigdata.bop.PipelineOp;
import com.bigdata.bop.engine.BOpStats;
import com.bigdata.bop.engine.IChunkAccessor;
import com.bigdata.relation.accesspath.IBlockingBuffer;
import com.bigdata.relation.accesspath.ThickAsynchronousIterator;
import cutthecrap.utils.striterators.ICloseableIterator;
/**
* This operator copies its source to its sink(s). Specializations exist which are
* used to feed the the initial set of intermediate results into a pipeline (
* {@link StartOp}) and which are used to replicate intermediate results to more
* than one sink ({@link Tee}).
*
* @see Annotations#SINK_REF
* @see Annotations#ALT_SINK_REF
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class CopyOp extends PipelineOp {
/**
*
*/
private static final long serialVersionUID = 1L;
public interface Annotations extends PipelineOp.Annotations {
/**
* An optional {@link IVariable}[] which specifies which variables will
* have their bindings copied.
*/
String SELECT = CopyOp.class.getName() + ".select";
/**
* An optional {@link IConstraint}[] which places restrictions on the
* legal patterns in the variable bindings.
*/
String CONSTRAINTS = CopyOp.class.getName() + ".constraints";
/**
* An optional {@link IBindingSet}[] to be used <strong>instead</strong>
* of the default source.
*/
String BINDING_SETS = CopyOp.class.getName() + ".bindingSets";
}
/**
* Deep copy constructor.
*
* @param op
*/
public CopyOp(CopyOp op) {
super(op);
}
/**
* Shallow copy constructor.
*
* @param args
* @param annotations
*/
public CopyOp(BOp[] args, Map<String, Object> annotations) {
super(args, annotations);
}
public CopyOp(final BOp[] args, NV... annotations) {
this(args, NV.asMap(annotations));
}
/**
* @see Annotations#SELECT
*/
public IVariable<?>[] getSelect() {
return getProperty(Annotations.SELECT, null/* defaultValue */);
}
/**
* @see Annotations#CONSTRAINTS
*/
public IConstraint[] constraints() {
return getProperty(Annotations.CONSTRAINTS, null/* defaultValue */);
}
/**
* @see Annotations#BINDING_SETS
*/
public IBindingSet[] bindingSets() {
return getProperty(Annotations.BINDING_SETS, null/* defaultValue */);
}
public FutureTask<Void> eval(final BOpContext<IBindingSet> context) {
return new FutureTask<Void>(new CopyTask(this, context));
}
/**
* Copy the source to the sink.
*
* @todo Optimize this. When using an {@link IChunkAccessor} we should be
* able to directly output the same chunk.
*/
static private class CopyTask implements Callable<Void> {
private final CopyOp op;
private final BOpContext<IBindingSet> context;
CopyTask(final CopyOp op,
final BOpContext<IBindingSet> context) {
this.op = op;
this.context = context;
}
public Void call() throws Exception {
// source.
final ICloseableIterator<IBindingSet[]> source = context
.getSource();
// default sink
final IBlockingBuffer<IBindingSet[]> sink = context.getSink();
// optional altSink.
final IBlockingBuffer<IBindingSet[]> sink2 = context.getSink2();
final BOpStats stats = context.getStats();
final IVariable<?>[] select = op.getSelect();
final IConstraint[] constraints = op.constraints();
try {
final IBindingSet[] bindingSets = op.bindingSets();
if (bindingSets != null) {
// copy optional additional binding sets.
BOpUtility.copy(
new ThickAsynchronousIterator<IBindingSet[]>(
new IBindingSet[][] { bindingSets }), sink,
sink2, null/* mergeSolution */, select,
constraints, stats);
} else {
// copy binding sets from the source.
BOpUtility
.copy(source, sink, sink2, null/* mergeSolution */,
select, constraints, stats);
}
// flush the sink.
sink.flush();
if (sink2 != null) // and the optional altSink.
sink2.flush();
// Done.
return null;
} finally {
sink.close();
if (sink2 != null)
sink2.close();
source.close();
}
}
} // class CopyTask
}