// Copyright 2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package org.apache.hivemind.management.impl;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import javax.management.JMException;
import javax.management.ObjectName;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.hivemind.InterceptorStack;
import org.apache.hivemind.ServiceInterceptorFactory;
import org.apache.hivemind.internal.Module;
import org.apache.hivemind.internal.ServicePoint;
import org.apache.hivemind.management.MBeanRegistry;
import org.apache.hivemind.management.ManagementMessages;
import org.apache.hivemind.management.ObjectNameBuilder;
import org.apache.hivemind.management.mbeans.PerformanceMonitorMBean;
import org.apache.hivemind.methodmatch.MethodMatcher;
import org.apache.hivemind.service.MethodContribution;
import org.apache.hivemind.service.MethodIterator;
import org.apache.hivemind.service.MethodSignature;
/**
* Interceptor factory that adds a MBean based performance monitor to a service. The interceptor
* collects the number of calls, and the duration for each intercepted method. The results are
* delegated to an {@link org.apache.hivemind.management.mbeans.PerformanceMonitorMBean MBean }that
* is created and registered in the MBeanServer. Which methods are intercepted can be defined like
* in the logging interceptor
*
* @author Achim Huegen
* @since 1.1
*/
public class PerformanceMonitorFactory implements ServiceInterceptorFactory
{
private static final String SERVICE_DECORATOR_TYPE = "PerformanceCollector";
private MBeanRegistry _mbeanRegistry;
private ObjectNameBuilder _objectNameBuilder;
private String _serviceId;
public PerformanceMonitorFactory(MBeanRegistry mbeanRegistry,
ObjectNameBuilder objectNameBuilder)
{
_mbeanRegistry = mbeanRegistry;
_objectNameBuilder = objectNameBuilder;
}
public void setServiceId(String string)
{
_serviceId = string;
}
/**
* Dynamic Proxy that counts method calls
*/
private class PerformanceMonitorHandler implements InvocationHandler
{
private Object _inner;
private PerformanceCollector _counter;
private Set _interceptedMethods;
PerformanceMonitorHandler(Object inner, PerformanceCollector counter, Set interceptedMethods)
{
_inner = inner;
_counter = counter;
_interceptedMethods = interceptedMethods;
}
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
{
try
{
// Filter the method
MethodSignature signature = new MethodSignature(method);
if (_interceptedMethods.contains(signature))
{
// clock the execution time
long startTime = System.currentTimeMillis();
Object result = method.invoke(_inner, args);
long endTime = System.currentTimeMillis();
_counter.addMeasurement(signature, endTime - startTime);
return result;
}
else
return method.invoke(_inner, args);
}
catch (InvocationTargetException ex)
{
throw ex.getTargetException();
}
}
}
public void createInterceptor(InterceptorStack stack, Module invokingModule, List parameters)
{
ServicePoint servicePoint = invokingModule.getServicePoint(stack
.getServiceExtensionPointId());
Set methods = getInterceptedMethods(stack, parameters);
try
{
PerformanceCollector counter = createMBean(servicePoint, methods);
InvocationHandler countHandler = new PerformanceMonitorHandler(stack.peek(), counter,
methods);
Object proxy = Proxy.newProxyInstance(invokingModule.getClassResolver()
.getClassLoader(), new Class[]
{ stack.getServiceInterface() }, countHandler);
stack.push(proxy);
}
catch (Exception ex)
{
throw new ApplicationRuntimeException(ManagementMessages
.errorInstantiatingPerformanceInterceptor(_serviceId, stack, ex), ex);
}
}
/**
* Creates and registers the MBean that holds the performance data.
*/
public PerformanceCollector createMBean(ServicePoint servicePoint, Set methods)
throws JMException
{
PerformanceCollector counter = new PerformanceMonitorMBean(methods);
ObjectName objectName = _objectNameBuilder.createServiceDecoratorName(
servicePoint,
SERVICE_DECORATOR_TYPE);
_mbeanRegistry.registerMBean(counter, null, objectName);
return counter;
}
/**
* Creates a method matcher that helps finding the intercepted methods
*/
private MethodMatcher buildMethodMatcher(List parameters)
{
MethodMatcher result = null;
Iterator i = parameters.iterator();
while (i.hasNext())
{
MethodContribution mc = (MethodContribution) i.next();
if (result == null)
result = new MethodMatcher();
result.put(mc.getMethodPattern(), mc);
}
return result;
}
/**
* Returns the methods that must be intercepted. Which methods are intercepted is controled by
* the interceptor parameters via include and exclude mechanism
*/
protected Set getInterceptedMethods(InterceptorStack stack, List parameters)
{
Set methods = new HashSet();
MethodMatcher matcher = buildMethodMatcher(parameters);
MethodIterator mi = new MethodIterator(stack.getServiceInterface());
while (mi.hasNext())
{
MethodSignature sig = mi.next();
if (includeMethod(matcher, sig))
methods.add(sig);
}
return methods;
}
private boolean includeMethod(MethodMatcher matcher, MethodSignature sig)
{
if (matcher == null)
return true;
MethodContribution mc = (MethodContribution) matcher.get(sig);
return mc == null || mc.getInclude();
}
}