/**************************************************************************************
* 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.core.service;
import com.espertech.esper.client.EPException;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.collection.UniformPair;
import com.espertech.esper.event.NaturalEventBean;
import com.espertech.esper.util.JavaClassHelper;
import net.sf.cglib.reflect.FastClass;
import net.sf.cglib.reflect.FastMethod;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Arrays;
/**
* A result delivery strategy that uses a matching "update" method and
* optional start, end, and updateRStream methods, to deliver column-wise to parameters
* of the update method.
*/
public class ResultDeliveryStrategyImpl implements ResultDeliveryStrategy
{
private static Log log = LogFactory.getLog(ResultDeliveryStrategyImpl.class);
private final String statementName;
private final Object subscriber;
private final FastMethod updateFastMethod;
private final FastMethod startFastMethod;
private final FastMethod endFastMethod;
private final FastMethod updateRStreamFastMethod;
private final DeliveryConvertor deliveryConvertor;
/**
* Ctor.
* @param subscriber is the subscriber receiving method invocations
* @param deliveryConvertor for converting individual rows
* @param method to deliver the insert stream to
* @param startMethod to call to indicate when delivery starts, or null if no such indication is required
* @param endMethod to call to indicate when delivery ends, or null if no such indication is required
* @param rStreamMethod to deliver the remove stream to, or null if no such indication is required
*/
public ResultDeliveryStrategyImpl(String statementName, Object subscriber, DeliveryConvertor deliveryConvertor, Method method, Method startMethod, Method endMethod, Method rStreamMethod)
{
this.statementName = statementName;
this.subscriber = subscriber;
this.deliveryConvertor = deliveryConvertor;
FastClass fastClass = FastClass.create(Thread.currentThread().getContextClassLoader(), subscriber.getClass());
this.updateFastMethod = fastClass.getMethod(method);
if (startMethod != null)
{
startFastMethod = fastClass.getMethod(startMethod);
}
else
{
startFastMethod = null;
}
if (endMethod != null)
{
endFastMethod = fastClass.getMethod(endMethod);
}
else
{
endFastMethod = null;
}
if (rStreamMethod != null)
{
updateRStreamFastMethod = fastClass.getMethod(rStreamMethod);
}
else
{
updateRStreamFastMethod = null;
}
}
public void execute(UniformPair<EventBean[]> result)
{
if (startFastMethod != null)
{
int countNew = 0;
int countOld = 0;
if (result != null) {
countNew = count(result.getFirst());
countOld = count(result.getSecond());
}
Object[] params = new Object[] {countNew, countOld};
try {
startFastMethod.invoke(subscriber, params);
}
catch (InvocationTargetException e) {
handle(statementName, log, e, params, subscriber, startFastMethod);
}
catch (Throwable t) {
handleThrowable(log, t, null, subscriber, startFastMethod);
}
}
EventBean[] newData = null;
EventBean[] oldData = null;
if (result != null)
{
newData = result.getFirst();
oldData = result.getSecond();
}
if ((newData != null) && (newData.length > 0)) {
for (int i = 0; i < newData.length; i++) {
EventBean event = newData[i];
if (event instanceof NaturalEventBean) {
NaturalEventBean natural = (NaturalEventBean) event;
Object[] params = deliveryConvertor.convertRow(natural.getNatural());
try {
updateFastMethod.invoke(subscriber, params);
}
catch (InvocationTargetException e) {
handle(statementName, log, e, params, subscriber, updateFastMethod);
}
catch (Throwable t) {
handleThrowable(log, t, params, subscriber, updateFastMethod);
}
}
}
}
if ((updateRStreamFastMethod != null) && (oldData != null) && (oldData.length > 0)) {
for (int i = 0; i < oldData.length; i++) {
EventBean event = oldData[i];
if (event instanceof NaturalEventBean) {
NaturalEventBean natural = (NaturalEventBean) event;
Object[] params = deliveryConvertor.convertRow(natural.getNatural());
try {
updateRStreamFastMethod.invoke(subscriber, params);
}
catch (InvocationTargetException e) {
handle(statementName, log, e, params, subscriber, updateRStreamFastMethod);
}
catch (Throwable t) {
handleThrowable(log, t, params, subscriber, updateRStreamFastMethod);
}
}
}
}
if (endFastMethod != null) {
try {
endFastMethod.invoke(subscriber, null);
}
catch (InvocationTargetException e) {
handle(statementName, log, e, null, subscriber, endFastMethod);
}
catch (Throwable t) {
handleThrowable(log, t, null, subscriber, endFastMethod);
}
}
}
/**
* Handle the exception, displaying a nice message and converting to {@link EPException}.
* @param logger is the logger to use for error logging
* @param e is the exception
* @param params the method parameters
* @param subscriber the object to deliver to
* @param method the method to call
* @throws EPException converted from the passed invocation exception
*/
protected static void handle(String statementName, Log logger, InvocationTargetException e, Object[] params, Object subscriber, FastMethod method) {
String message = JavaClassHelper.getMessageInvocationTarget(statementName, method.getJavaMethod(), subscriber.getClass().getName(), params, e);
logger.error(message, e.getTargetException());
}
/**
* Handle the exception, displaying a nice message and converting to {@link EPException}.
* @param logger is the logger to use for error logging
* @param t is the throwable
* @param params the method parameters
* @param subscriber the object to deliver to
* @param method the method to call
* @throws EPException converted from the passed invocation exception
*/
protected static void handleThrowable(Log logger, Throwable t, Object[] params, Object subscriber, FastMethod method) {
String message = "Unexpected exception when invoking method '" + method.getName() +
"' on subscriber class '" + subscriber.getClass().getSimpleName() +
"' for parameters " + ((params == null) ? "null" : Arrays.toString(params)) +
" : " + t.getClass().getSimpleName() + " : " + t.getMessage();
logger.error(message, t);
}
private int count(EventBean[] events) {
if (events == null)
{
return 0;
}
int count = 0;
for (int i = 0; i < events.length; i++)
{
EventBean event = events[i];
if (event instanceof NaturalEventBean)
{
count++;
}
}
return count;
}
}