/*
***************************************************************************************
* 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.expression.visitor;
import com.espertech.esper.epl.enummethod.dot.ExprLambdaGoesNode;
import com.espertech.esper.epl.expression.baseagg.ExprAggregateNode;
import com.espertech.esper.epl.expression.core.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class ExprNodeIdentifierAndStreamRefVisitor implements ExprNodeVisitor {
private final boolean isVisitAggregateNodes;
private List<ExprNodePropOrStreamDesc> refs;
public ExprNodeIdentifierAndStreamRefVisitor(boolean isVisitAggregateNodes) {
this.isVisitAggregateNodes = isVisitAggregateNodes;
}
public boolean isVisit(ExprNode exprNode) {
if (exprNode instanceof ExprLambdaGoesNode) {
return false;
}
if (isVisitAggregateNodes) {
return true;
}
return !(exprNode instanceof ExprAggregateNode);
}
public List<ExprNodePropOrStreamDesc> getRefs() {
if (refs == null) {
return Collections.emptyList();
}
return refs;
}
public void visit(ExprNode exprNode) {
if (exprNode instanceof ExprIdentNode) {
ExprIdentNode identNode = (ExprIdentNode) exprNode;
int streamId = identNode.getStreamId();
String propertyName = identNode.getResolvedPropertyName();
checkAllocatedRefs();
refs.add(new ExprNodePropOrStreamPropDesc(streamId, propertyName));
} else if (exprNode instanceof ExprStreamRefNode) {
ExprStreamRefNode streamRefNode = (ExprStreamRefNode) exprNode;
Integer stream = streamRefNode.getStreamReferencedIfAny();
checkAllocatedRefs();
if (stream != null) {
refs.add(new ExprNodePropOrStreamExprDesc(stream, streamRefNode));
}
}
}
public void reset() {
if (refs != null) {
refs.clear();
}
}
private void checkAllocatedRefs() {
if (refs == null) {
refs = new ArrayList<ExprNodePropOrStreamDesc>(4);
}
}
}