com.bigdata.rdf.sparql.ast.ConstructNode 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 Aug 24, 2011
*/
package com.bigdata.rdf.sparql.ast;
import java.util.Map;
import com.bigdata.bop.BOp;
import com.bigdata.rdf.sparql.ast.eval.AST2BOpContext;
import com.bigdata.rdf.spo.ISPO;
/**
* A template for the construction of one or more graphs based on the solutions
* projected by a query.
*
* @author Bryan Thompson
* @version $Id$
*/
public class ConstructNode extends AbstractStatementContainer
//GroupNodeBase
implements IStatementContainer {
/**
*
*/
private static final long serialVersionUID = 1L;
public interface Annotations extends AbstractStatementContainer.Annotations {
/**
* Boolean property (default {@value #DEFAULT_NATIVE_DISTINCT}) which is
* true iff a native DISTINCT {@link ISPO} filter should be
* applied (large cardinality is expected for the constructed graph).
* When false, a JVM based DISTINCT {@link ISPO} filter
* will be applied.
*
* Note: This can be set using either {@link QueryHints#ANALYTIC} or
* {@link QueryHints#NATIVE_DISTINCT_SPO}.
*
* @see
* CONSTRUCT should apply DISTINCT (s,p,o) filter
*/
String NATIVE_DISTINCT = "nativeDistinct";
/**
* Internal boolean property (default {@value #DEFAULT_DISTINCT_QUDS}) which is
* true when used internally for constructing sets of quads rather
* than sets of triples.
*
* Note: This can only be set programmatically using {@link ConstructNode#setDistinctQuads(boolean)}
*
* Note: When this property is set and mixed quads are detected or suspected then the {@link #NATIVE_DISTINCT} property is ignored.
*
* @see
* CONSTRUCT should apply DISTINCT (s,p,o) filter
*/
String DISTINCT_QUADS = "quadsDistinct";
boolean DEFAULT_NATIVE_DISTINCT = false;
boolean DEFAULT_DISTINCT_QUADS = false;
}
public ConstructNode() {
super();
}
public ConstructNode(final AST2BOpContext ctx) {
super();
if (ctx.nativeDistinctSPO) {
// Native DISTINCT SPO FILTER is requested.
setNativeDistinct(true);
}
}
/**
* Constructor required for {@link com.bigdata.bop.BOpUtility#deepCopy(FilterNode)}.
*/
public ConstructNode(final ConstructNode op) {
super(op);
}
/**
* Required shallow copy constructor.
*/
public ConstructNode(final BOp[] args, final Map anns) {
super(args, anns);
}
@Override
public IGroupNode addChild(
final StatementPatternNode child) {
if (!(child instanceof StatementPatternNode))
throw new UnsupportedOperationException();
super.addChild(child);
return this;
}
/**
* When true, a native DISTINCT {@link ISPO} filter will be
* applied to the constructed graph, otherwise a Java Heap based DISTINCT
* {@link ISPO} filter will be applied.
*
* @see Annotations#NATIVE_DISTINCT
*
* @see
* CONSTRUCT should apply DISTINCT (s,p,o) filter
*/
public boolean isNativeDistinct() {
return getProperty(Annotations.NATIVE_DISTINCT,
Annotations.DEFAULT_NATIVE_DISTINCT);
}
public void setNativeDistinct(final boolean nativeDistinct) {
setProperty(Annotations.NATIVE_DISTINCT, nativeDistinct);
}
public boolean isDistinctQuads() {
return getProperty(Annotations.DISTINCT_QUADS,
Annotations.DEFAULT_DISTINCT_QUADS);
}
public void setDistinctQuads(final boolean quads) {
setProperty(Annotations.DISTINCT_QUADS, quads);
}
@Override
public String toString(final int indent) {
final StringBuilder sb = new StringBuilder();
final String s = indent(indent);
sb.append("\n").append(s).append("CONSTRUCT {");
for (StatementPatternNode v : this) {
sb.append(v.toString(indent+1));
}
sb.append("\n").append(s).append("}");
if (isNativeDistinct())
sb.append(" [nativeDistinct]");
return sb.toString();
}
}