| /* |
| * 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 org.apache.hyracks.algebricks.runtime.base.IScalarEvaluator; |
| import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluatorFactory; |
| import org.apache.hyracks.api.context.IHyracksTaskContext; |
| import org.apache.hyracks.api.exceptions.HyracksDataException; |
| import org.apache.hyracks.data.std.api.IPointable; |
| import org.apache.vxquery.datamodel.accessors.SequencePointable; |
| import org.apache.vxquery.datamodel.accessors.TaggedValuePointable; |
| 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; |
| |
| public class FnExactlyOneScalarEvaluatorFactory extends AbstractTaggedValueArgumentScalarEvaluatorFactory { |
| private static final long serialVersionUID = 1L; |
| |
| public FnExactlyOneScalarEvaluatorFactory(IScalarEvaluatorFactory[] args) { |
| super(args); |
| } |
| |
| @Override |
| protected IScalarEvaluator createEvaluator(IHyracksTaskContext ctx, IScalarEvaluator[] args) |
| throws HyracksDataException { |
| final SequencePointable seqp = (SequencePointable) SequencePointable.FACTORY.createPointable(); |
| return new AbstractTaggedValueArgumentScalarEvaluator(args) { |
| @Override |
| protected void evaluate(TaggedValuePointable[] args, IPointable result) throws SystemException { |
| TaggedValuePointable tvp = args[0]; |
| if (tvp.getTag() == ValueTag.SEQUENCE_TAG) { |
| tvp.getValue(seqp); |
| if (seqp.getEntryCount() == 1) { |
| result.set(tvp); |
| } else { |
| throw new SystemException(ErrorCode.FORG0005); |
| } |
| } else { |
| result.set(tvp); |
| } |
| } |
| }; |
| } |
| } |