com.bigdata.bop.rdf.aggregate.AVERAGE Maven / Gradle / Ivy
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/**
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
*/
package com.bigdata.bop.rdf.aggregate;
import java.util.Map;
import org.openrdf.model.Literal;
import org.openrdf.model.URI;
import org.openrdf.model.datatypes.XMLDatatypeUtil;
import com.bigdata.bop.BOp;
import com.bigdata.bop.IBindingSet;
import com.bigdata.bop.IValueExpression;
import com.bigdata.bop.aggregate.AggregateBase;
import com.bigdata.rdf.error.SparqlTypeErrorException;
import com.bigdata.rdf.internal.IV;
import com.bigdata.rdf.internal.IVUtility;
import com.bigdata.rdf.internal.NotMaterializedException;
import com.bigdata.rdf.internal.constraints.INeedsMaterialization;
import com.bigdata.rdf.internal.constraints.IVValueExpression;
import com.bigdata.rdf.internal.constraints.MathBOp;
import com.bigdata.rdf.internal.constraints.MathUtility;
import com.bigdata.rdf.internal.constraints.MathBOp.MathOp;
import com.bigdata.rdf.internal.impl.literal.NumericIV;
import com.bigdata.rdf.internal.impl.literal.XSDNumericIV;
import com.bigdata.rdf.model.BigdataLiteral;
import com.bigdata.rdf.model.BigdataValue;
/**
* Operator computes the running sum over the presented binding sets for the
* given variable. A missing value does not contribute towards the sum.
*
* @author thompsonbry
*/
public class AVERAGE extends AggregateBase implements INeedsMaterialization {
// private static final transient Logger log = Logger.getLogger(AVERAGE.class);
/**
*
*/
private static final long serialVersionUID = 1L;
public AVERAGE(AVERAGE op) {
super(op);
}
public AVERAGE(BOp[] args, Map annotations) {
super(args, annotations);
}
public AVERAGE(boolean distinct, IValueExpression expr) {
super( distinct, expr);
}
/**
* The running aggregate value.
*
* Note: SUM() returns ZERO if there are no non-error solutions presented.
* This assumes that the ZERO will be an xsd:int ZERO.
*
* Note: This field is guarded by the monitor on the {@link AVERAGE}
* instance.
*/
private transient NumericIV aggregated = ZERO;
/**
* The #of observed values.
*/
private transient long n = 0;
/**
* The first error encountered since the last {@link #reset()}.
*/
private transient Throwable firstCause = null;
synchronized public void reset() {
aggregated = ZERO;
n = 0;
firstCause = null;
}
synchronized public IV done() {
if (firstCause != null) {
throw new RuntimeException(firstCause);
}
if(n == 0)
return ZERO;
return MathUtility.literalMath(aggregated,
new XSDNumericIV(n), MathBOp.MathOp.DIVIDE);
}
synchronized public IV get(final IBindingSet bindingSet) {
try {
return doGet(bindingSet);
} catch (Throwable t) {
if (firstCause == null) {
firstCause = t;
}
throw new RuntimeException(t);
}
}
private IV doGet(final IBindingSet bindingSet) {
final IValueExpression expr = (IValueExpression) get(0);
final IV iv = expr.get(bindingSet);
if (iv != null) {
/*
* Aggregate non-null literal values.
*/
/*
* Aggregate non-null literal values.
*/
final Literal lit = IVValueExpression.asLiteral(iv);
if (!MathUtility.checkNumericDatatype(lit))
throw new SparqlTypeErrorException();
aggregated =
MathUtility.literalMath(aggregated, lit, MathOp.PLUS);
// if (!iv.isLiteral())
// throw new SparqlTypeErrorException();
//
// if (iv.isInline()) {
//
// // Two IVs.
// aggregated = IVUtility.numericalMath(iv, aggregated,
// MathOp.PLUS);
//
// } else {
//
// // One IV and one Literal.
// final BigdataValue val1 = iv.getValue();
//
// if (val1 == null)
// throw new NotMaterializedException();
//
//// if (!(val1 instanceof Literal))
//// throw new SparqlTypeErrorException();
//
// // Only numeric value can be used in math expressions
// final URI dt1 = ((Literal)val1).getDatatype();
// if (dt1 == null || !XMLDatatypeUtil.isNumericDatatype(dt1))
// throw new SparqlTypeErrorException();
//
// aggregated = IVUtility.numericalMath((Literal) val1,
// aggregated, MathOp.PLUS);
//
// }
n++;
}
return aggregated;
}
/**
* Note: {@link AVERAGE} only works on numerics. If they are inline, then that
* is great. Otherwise it will handle a materialized numeric literal and do
* type promotion, which always results in a signed inline number IV and
* then operate on that.
*
* FIXME MikeP: What is the right return value here?
*/
public Requirement getRequirement() {
return INeedsMaterialization.Requirement.ALWAYS;
}
}