/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.query.function.aggregate;
import java.util.List;
import org.teiid.api.exception.query.ExpressionEvaluationException;
import org.teiid.api.exception.query.FunctionExecutionException;
import org.teiid.core.TeiidComponentException;
import org.teiid.core.TeiidProcessingException;
import org.teiid.core.types.ArrayImpl;
import org.teiid.query.util.CommandContext;
/**
* We store up to three values related to the lead/lag per row
*/
public class LeadLagValue extends AggregateFunction {
private Object[] vals = null;
private int partition = 0;
@Override
public void addInputDirect(List<?> tuple, CommandContext commandContext)
throws TeiidComponentException, TeiidProcessingException {
vals = new Object[argIndexes.length + 1];
for (int i = 0; i < argIndexes.length; i++) {
vals[i] = tuple.get(argIndexes[i]);
}
vals[argIndexes.length] = partition;
}
@Override
public Object getResult(CommandContext commandContext)
throws FunctionExecutionException, ExpressionEvaluationException,
TeiidComponentException, TeiidProcessingException {
return new ArrayImpl(vals);
}
@Override
public void reset() {
vals = null;
partition++;
}
@Override
public boolean respectsNull() {
return true;
}
}