/**
* Copyright (c) 2013, Institute of Information Systems (Sven Groppe and contributors of LUPOSDATE), University of Luebeck
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this list of conditions and the following
* disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other materials provided with the distribution.
* - Neither the name of the University of Luebeck nor the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package lupos.engine.operators.singleinput;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import lupos.datastructures.bindings.Bindings;
import lupos.datastructures.items.Item;
import lupos.datastructures.items.Variable;
import lupos.datastructures.queryresult.QueryResult;
import lupos.engine.operators.tripleoperator.TriplePattern;
import lupos.misc.BitVector;
public class SIPFilterOperator extends SingleInputOperator {
protected final Collection<TriplePattern> ctp;
protected final Collection<Variable> vars;
protected final Collection<BitVector> bloomFilters;
public static int NUMBEROFBITSFORBLOOMFILTER = 1024 * 8;
public SIPFilterOperator(final Collection<TriplePattern> ctp,
final Collection<Variable> vars) {
super();
this.ctp = new LinkedList<TriplePattern>();
for (final TriplePattern tp : ctp) {
for (final Variable v : vars)
if (tp.getVariables().contains(v)) {
this.ctp.add(tp);
continue;
}
}
this.vars = vars;
bloomFilters = new LinkedList<BitVector>();
for (int i = 0; i < vars.size(); i++)
bloomFilters.add(new BitVector(NUMBEROFBITSFORBLOOMFILTER));
}
@Override
public synchronized QueryResult process(final QueryResult res,
final int operandID) {
for (final Bindings b : res) {
final Iterator<BitVector> ibv = bloomFilters.iterator();
for (final Variable v : vars) {
final BitVector bv = ibv.next();
// if (!bv.get((b.get(v).hashCode() %
// NUMBEROFBITSFORBLOOMFILTER)))
// System.out.println(b.get(v));
bv.set(Math.abs(b.get(v).hashCode()
% NUMBEROFBITSFORBLOOMFILTER));
}
}
// System.out.println(bloomFilters.iterator().next().count());
for (final TriplePattern tp : ctp) {
// inform triple patterns of bloom filter!
int i = 0;
for (final Item item : tp) {
if (item.isVariable()) {
final Iterator<BitVector> ibv = bloomFilters.iterator();
for (final Variable v : vars) {
final BitVector bloomFilter = ibv.next();
if (v.equals(item)) {
BitVector[] bfa = tp.getBloomFilters();
if (bfa == null) {
bfa = new BitVector[3];
bfa[i] = bloomFilter;
} else {
if (bfa[i] != null) {
if (!bfa[i].equals(bloomFilter))
for (int j = 0; j < bloomFilter.size(); j++)
if (!bloomFilter.get(j))
bfa[i].clear(j);
} else
bfa[i] = bloomFilter;
}
tp.setBloomFilters(bfa);
}
}
}
i++;
}
}
return res;
}
@Override
public String toString() {
return super.toString() + "\nBloom Filters on " + vars
+ "\ninforming triple patterns " + ctp;
}
@Override
public String toString(final lupos.rdf.Prefix prefixInstance) {
String s = super.toString() + "\nBloom Filters on " + vars
+ "\ninforming triple patterns [";
boolean first = true;
for (final TriplePattern tp : ctp) {
if (first) {
first = false;
} else
s += ", ";
s += tp.toString(prefixInstance);
}
return s + "]";
}
}