/*
***************************************************************************************
* Copyright (C) 2006 EsperTech, Inc. All rights reserved. *
* http://www.espertech.com/esper *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
***************************************************************************************
*/
package com.espertech.esper.epl.agg.factory;
import com.espertech.esper.client.EventType;
import com.espertech.esper.epl.agg.access.AggregationAccessor;
import com.espertech.esper.epl.agg.access.AggregationAgent;
import com.espertech.esper.epl.agg.access.AggregationStateKey;
import com.espertech.esper.epl.agg.aggregator.AggregationMethod;
import com.espertech.esper.epl.agg.aggregator.AggregatorNth;
import com.espertech.esper.epl.agg.aggregator.AggregatorNthFilter;
import com.espertech.esper.epl.agg.service.AggregationMethodFactory;
import com.espertech.esper.epl.agg.service.AggregationStateFactory;
import com.espertech.esper.epl.agg.service.AggregationValidationUtil;
import com.espertech.esper.epl.expression.baseagg.ExprAggregateNodeBase;
import com.espertech.esper.epl.expression.core.ExprEvaluator;
import com.espertech.esper.epl.expression.core.ExprValidationException;
import com.espertech.esper.epl.expression.methodagg.ExprMethodAggUtil;
import com.espertech.esper.epl.expression.methodagg.ExprNthAggNode;
public class AggregationMethodFactoryNth implements AggregationMethodFactory {
protected final ExprNthAggNode parent;
protected final Class childType;
protected final int size;
public AggregationMethodFactoryNth(ExprNthAggNode parent, Class childType, int size) {
this.parent = parent;
this.childType = childType;
this.size = size;
}
public boolean isAccessAggregation() {
return false;
}
public Class getResultType() {
return childType;
}
public AggregationStateKey getAggregationStateKey(boolean isMatchRecognize) {
throw new IllegalStateException("Not an access aggregation function");
}
public AggregationStateFactory getAggregationStateFactory(boolean isMatchRecognize) {
throw new IllegalStateException("Not an access aggregation function");
}
public AggregationAccessor getAccessor() {
throw new IllegalStateException("Not an access aggregation function");
}
public AggregationMethod make() {
AggregationMethod method;
if (parent.getOptionalFilter() != null) {
method = new AggregatorNthFilter(size + 1);
} else {
method = new AggregatorNth(size + 1);
}
if (!parent.isDistinct()) {
return method;
}
return AggregationMethodFactoryUtil.makeDistinctAggregator(method, false);
}
public ExprAggregateNodeBase getAggregationExpression() {
return parent;
}
public void validateIntoTableCompatible(AggregationMethodFactory intoTableAgg) throws ExprValidationException {
AggregationValidationUtil.validateAggregationType(this, intoTableAgg);
AggregationMethodFactoryNth that = (AggregationMethodFactoryNth) intoTableAgg;
AggregationValidationUtil.validateAggregationInputType(childType, that.childType);
if (size != that.size) {
throw new ExprValidationException("The size is " +
size +
" and provided is " +
that.size);
}
}
public AggregationAgent getAggregationStateAgent() {
return null;
}
public ExprEvaluator getMethodAggregationEvaluator(boolean join, EventType[] typesPerStream) throws ExprValidationException {
return ExprMethodAggUtil.getDefaultEvaluator(parent.getPositionalParams(), join, typesPerStream);
}
}