/**************************************************************************************
* Copyright (C) 2008 EsperTech, Inc. All rights reserved. *
* http://esper.codehaus.org *
* 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;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventType;
import com.espertech.esper.epl.enummethod.dot.ExprDotEvalTypeInfo;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.List;
import java.util.Map;
/**
* Represents an invocation of a instance method on an event of a given stream in the expression tree.
*/
public class ExprStreamInstanceMethodNode extends ExprNodeBase implements ExprEvaluator, ExprNodeInnerNodeProvider
{
private static final Log log = LogFactory.getLog(ExprNode.class);
private static final long serialVersionUID = 3422689488586035557L;
private final String streamName;
private final List<ExprChainedSpec> chainSpec;
private int streamNum = -1;
private transient ExprDotEval[] evaluators;
/**
* Ctor.
* @param streamName - the declaring class for the method that this node will invoke
*/
public ExprStreamInstanceMethodNode(String streamName, List<ExprChainedSpec> chainSpec)
{
if(streamName == null)
{
throw new NullPointerException("Stream name is null");
}
if((chainSpec == null) || (chainSpec.isEmpty()))
{
throw new NullPointerException("chain name is null or empty");
}
this.streamName = streamName;
this.chainSpec = chainSpec;
}
@Override
public ExprEvaluator getExprEvaluator() {
return this;
}
public boolean isConstantResult()
{
return false;
}
@Override
public Map<String, Object> getEventType() {
return null;
}
/**
* Returns the stream name.
* @return the stream that provides events that provide the instance method
*/
public String getStreamName() {
return streamName;
}
/**
* Returns stream id supplying the property value.
* @return stream number
*/
public int getStreamId()
{
if (streamNum == -1)
{
throw new IllegalStateException("Stream underlying node has not been validated");
}
return streamNum;
}
public String toExpressionString()
{
StringBuilder buffer = new StringBuilder();
buffer.append(streamName);
ExprNodeUtility.toExpressionString(chainSpec, buffer, true);
return buffer.toString();
}
public boolean equalsNode(ExprNode node)
{
if(!(node instanceof ExprStreamInstanceMethodNode))
{
return false;
}
ExprStreamInstanceMethodNode other = (ExprStreamInstanceMethodNode) node;
if (!streamName.equals(other.streamName)) {
return false;
}
if (other.chainSpec.size() != this.chainSpec.size()) {
return false;
}
for (int i = 0; i < chainSpec.size(); i++) {
if (!(this.chainSpec.get(i).equals(other.chainSpec.get(i)))) {
return false;
}
}
return true;
}
public void validate(ExprValidationContext validationContext) throws ExprValidationException
{
String[] streams = validationContext.getStreamTypeService().getStreamNames();
for (int i = 0; i < streams.length; i++)
{
if ((streams[i] != null) && (streams[i].equals(streamName)))
{
streamNum = i;
break;
}
}
if (streamNum == -1)
{
throw new ExprValidationException("Stream by name '" + streamName + "' could not be found among all streams");
}
EventType eventType = validationContext.getStreamTypeService().getEventTypes()[streamNum];
Class type = eventType.getUnderlyingType();
ExprDotEvalTypeInfo typeInfo = ExprDotEvalTypeInfo.scalarOrUnderlying(type);
evaluators = ExprDotNodeUtility.getChainEvaluators(typeInfo, chainSpec, validationContext, false).getSecond();
}
public Class getType()
{
if (evaluators == null)
{
throw new IllegalStateException("Stream underlying node has not been validated");
}
return evaluators[evaluators.length - 1].getTypeInfo().getScalar();
}
public Object evaluate(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext)
{
// get underlying event
EventBean event = eventsPerStream[streamNum];
if (event == null)
{
return null;
}
Object inner = event.getUnderlying();
if (inner == null) {
return null;
}
for (ExprDotEval methodEval : evaluators) {
inner = methodEval.evaluate(inner, eventsPerStream, isNewData, exprEvaluatorContext);
if (inner == null) {
break;
}
}
return inner;
}
@Override
public void accept(ExprNodeVisitor visitor) {
super.accept(visitor);
ExprNodeUtil.acceptChain(visitor, chainSpec);
}
@Override
public void accept(ExprNodeVisitorWithParent visitor) {
super.accept(visitor);
ExprNodeUtil.acceptChain(visitor, chainSpec);
}
@Override
public void acceptChildnodes(ExprNodeVisitorWithParent visitor, ExprNode parent) {
super.acceptChildnodes(visitor, parent);
ExprNodeUtil.acceptChain(visitor, chainSpec, this);
}
@Override
public void replaceUnlistedChildNode(ExprNode nodeToReplace, ExprNode newNode) {
ExprNodeUtil.replaceChainChildNode(nodeToReplace, newNode, chainSpec);
}
@Override
public List<ExprNode> getAdditionalNodes() {
return ExprNodeUtility.collectChainParameters(chainSpec);
}
}