/**
* 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.multiinput.mergeunion;
import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import lupos.datastructures.bindings.Bindings;
import lupos.datastructures.items.Variable;
import lupos.datastructures.items.literal.Literal;
import lupos.datastructures.queryresult.QueryResult;
public class MergeUnionIterator extends MergeIterator<Bindings> implements
Iterator<Bindings> {
public MergeUnionIterator(final QueryResult[] operandResults,
final boolean moreThanOnce, final Comparator<Bindings> comparator) {
init(getArray(operandResults, moreThanOnce), comparator);
}
protected Iterator<Bindings>[] getArray(final QueryResult[] operandResults,
final boolean moreThanOnce) {
int minus = 0;
for (int i = 0; i < operandResults.length; i++) {
if (operandResults[i] == null)
minus--;
}
final Iterator<Bindings>[] ita = new Iterator[operandResults.length
- minus];
int index = 0;
for (int i = 0; i < operandResults.length; i++) {
if (operandResults[i] != null)
ita[index++] = (moreThanOnce) ? operandResults[i].iterator()
: operandResults[i].oneTimeIterator();
}
return ita;
}
protected Iterator<Bindings>[] getArray(
final List<QueryResult> operandResults, final boolean moreThanOnce) {
final Iterator<Bindings>[] ita = new Iterator[operandResults.size()];
final Iterator<QueryResult> itqr = operandResults.iterator();
for (int i = 0; i < operandResults.size(); i++) {
final QueryResult qr = itqr.next();
ita[i] = (moreThanOnce) ? qr.iterator() : qr.oneTimeIterator();
}
return ita;
}
protected Iterator<Bindings>[] getArray(
final Collection<Iterator<Bindings>> operandResults) {
final Iterator<Bindings>[] ita = new Iterator[operandResults.size()];
final Iterator<Iterator<Bindings>> ititb = operandResults.iterator();
for (int i = 0; i < operandResults.size(); i++) {
ita[i] = ititb.next();
}
return ita;
}
public MergeUnionIterator(
final Collection<Iterator<Bindings>> operandResults,
final Comparator<Bindings> comparator) {
init(getArray(operandResults), comparator);
}
public MergeUnionIterator(
final Collection<Iterator<Bindings>> operandResults,
final Collection<Variable> toCompare) {
this(operandResults, new Comparator<Bindings>() {
public int compare(final Bindings o1, final Bindings o2) {
for (final Variable var : toCompare) {
final Literal l1 = o1.get(var);
final Literal l2 = o2.get(var);
if (l1 != null && l2 != null) {
final int compare = l1
.compareToNotNecessarilySPARQLSpecificationConform(l2);
if (compare != 0)
return compare;
} else if (l1 != null)
return -1;
else if (l2 != null)
return 1;
}
return 0;
}
});
}
public MergeUnionIterator(final QueryResult[] operandResults,
final boolean moreThanOnce, final Collection<Variable> toCompare) {
this(operandResults, moreThanOnce, new Comparator<Bindings>() {
public int compare(final Bindings o1, final Bindings o2) {
for (final Variable var : toCompare) {
final Literal l1 = o1.get(var);
final Literal l2 = o2.get(var);
if (l1 != null && l2 != null) {
final int compare = l1
.compareToNotNecessarilySPARQLSpecificationConform(l2);
if (compare != 0)
return compare;
} else if (l1 != null)
return -1;
else if (l2 != null)
return 1;
}
return 0;
}
});
}
public MergeUnionIterator(final List<QueryResult> operandResults,
final boolean moreThanOnce, final Collection<Variable> toCompare) {
this(operandResults, moreThanOnce, new Comparator<Bindings>() {
public int compare(final Bindings o1, final Bindings o2) {
for (final Variable var : toCompare) {
final Literal l1 = o1.get(var);
final Literal l2 = o2.get(var);
if (l1 != null && l2 != null) {
final int compare = l1
.compareToNotNecessarilySPARQLSpecificationConform(l2);
if (compare != 0)
return compare;
} else if (l1 != null)
return -1;
else if (l2 != null)
return 1;
}
return 0;
}
});
}
public MergeUnionIterator(final List<QueryResult> operandResults,
final boolean moreThanOnce, final Comparator<Bindings> comparator) {
init(getArray(operandResults, moreThanOnce), comparator);
}
}