/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.vxquery.runtime.functions.sequence;
import java.io.IOException;
import org.apache.vxquery.context.DynamicContext;
import org.apache.vxquery.datamodel.accessors.SequencePointable;
import org.apache.vxquery.datamodel.accessors.TaggedValuePointable;
import org.apache.vxquery.datamodel.accessors.TypedPointables;
import org.apache.vxquery.datamodel.builders.sequence.SequenceBuilder;
import org.apache.vxquery.datamodel.values.ValueTag;
import org.apache.vxquery.exceptions.ErrorCode;
import org.apache.vxquery.exceptions.SystemException;
import org.apache.vxquery.runtime.functions.base.AbstractTaggedValueArgumentScalarEvaluator;
import org.apache.vxquery.runtime.functions.base.AbstractTaggedValueArgumentScalarEvaluatorFactory;
import org.apache.vxquery.runtime.functions.comparison.AbstractValueComparisonOperation;
import org.apache.vxquery.runtime.functions.comparison.ValueEqComparisonOperation;
import org.apache.vxquery.runtime.functions.util.FunctionHelper;
import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
import edu.uci.ics.hyracks.algebricks.runtime.base.IScalarEvaluator;
import edu.uci.ics.hyracks.algebricks.runtime.base.IScalarEvaluatorFactory;
import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
import edu.uci.ics.hyracks.data.std.api.IPointable;
import edu.uci.ics.hyracks.data.std.primitive.UTF8StringPointable;
import edu.uci.ics.hyracks.data.std.primitive.VoidPointable;
import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
public class FnDistinctValuesScalarEvaluatorFactory extends AbstractTaggedValueArgumentScalarEvaluatorFactory {
private static final long serialVersionUID = 1L;
public FnDistinctValuesScalarEvaluatorFactory(IScalarEvaluatorFactory[] args) {
super(args);
}
@Override
protected IScalarEvaluator createEvaluator(IHyracksTaskContext ctx, IScalarEvaluator[] args)
throws AlgebricksException {
final ArrayBackedValueStorage abvs = new ArrayBackedValueStorage();
final SequenceBuilder sb = new SequenceBuilder();
final SequencePointable seq = new SequencePointable();
final DynamicContext dCtx = (DynamicContext) ctx.getJobletContext().getGlobalJobData();
final AbstractValueComparisonOperation aOp = new ValueEqComparisonOperation();
final TaggedValuePointable tvpDistinct = (TaggedValuePointable) TaggedValuePointable.FACTORY.createPointable();
final TaggedValuePointable tvpCheck = (TaggedValuePointable) TaggedValuePointable.FACTORY.createPointable();
final VoidPointable p = (VoidPointable) VoidPointable.FACTORY.createPointable();
final UTF8StringPointable stringp = (UTF8StringPointable) UTF8StringPointable.FACTORY.createPointable();
final TypedPointables tp1 = new TypedPointables();
final TypedPointables tp2 = new TypedPointables();
return new AbstractTaggedValueArgumentScalarEvaluator(args) {
@Override
protected void evaluate(TaggedValuePointable[] args, IPointable result) throws SystemException {
try {
abvs.reset();
sb.reset(abvs);
TaggedValuePointable tvp1 = args[0];
// Second parameter is optional.
if (args.length > 1) {
TaggedValuePointable tvp2 = args[1];
if (tvp2.getTag() != ValueTag.XS_STRING_TAG) {
throw new SystemException(ErrorCode.FORG0006);
}
tvp2.getValue(stringp);
}
// TODO use the third value as collation
if (tvp1.getTag() == ValueTag.SEQUENCE_TAG) {
tvp1.getValue(seq);
int seqLen = seq.getEntryCount();
// Add remaining distinct item.
boolean found = false;
for (int j = 0; j < seqLen; ++j) {
seq.getEntry(j, p);
tvpDistinct.set(p.getByteArray(), p.getStartOffset(), p.getLength());
// Check if item is distinct.
if (j + 1 < seqLen) {
for (int k = j + 1; k < seqLen; ++k) {
seq.getEntry(k, p);
tvpCheck.set(p.getByteArray(), p.getStartOffset(), p.getLength());
if (FunctionHelper.compareTaggedValues(aOp, tvpDistinct, tvpCheck, dCtx, tp1, tp2)) {
found = true;
break;
}
}
}
// Add distinct item.
if (!found) {
sb.addItem(tvpDistinct);
}
}
} else {
sb.addItem(tvp1);
}
sb.finish();
result.set(abvs);
} catch (IOException e) {
throw new SystemException(ErrorCode.SYSE0001);
}
}
};
}
}