/*
* 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.Arrays;
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.query.sql.symbol.Constant;
import org.teiid.query.util.CommandContext;
/**
*/
public class Max extends SingleArgumentAggregateFunction {
private Object maxValue;
private Class<?> outputType;
public void reset() {
maxValue = null;
}
@Override
public void initialize(Class<?> dataType, Class<?> inputType) {
this.outputType = inputType;
}
/**
* @see org.teiid.query.function.aggregate.AggregateFunction#addInputDirect(List, CommandContext, CommandContext)
*/
public void addInputDirect(Object value, List<?> tuple, CommandContext commandContext)
throws FunctionExecutionException, ExpressionEvaluationException, TeiidComponentException {
if(maxValue == null) {
maxValue = value;
} else {
Comparable valueComp = (Comparable) value;
if (Constant.COMPARATOR.compare(valueComp, maxValue) > 0) {
maxValue = valueComp;
}
}
}
/**
* @see org.teiid.query.function.aggregate.AggregateFunction#getResult(CommandContext)
*/
public Object getResult(CommandContext commandContext) {
return this.maxValue;
}
@Override
public List<? extends Class<?>> getStateTypes() {
return Arrays.asList(outputType);
}
@Override
public void getState(List<Object> state) {
state.add(maxValue);
}
@Override
public int setState(List<?> state, int index) {
this.maxValue = state.get(index);
return index++;
}
}