[WICKET-4971] AtmosphereEventSubscriptionCollector is slow

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 6.5.0
• Component/s: wicket-atmosphere
• Assignee: Emond Papegaaij
• Reporter: Andrei Badea
• Created: 11/Jan/13 16:30
• Updated: 14/Jan/13 12:20
• Resolved: 14/Jan/13 07:33

Description

AtmosphereEventSubscriptionCollector.onBeforeRender() is called so often that the amount of work it performs starts being significant. The method was a hotspot in our performance tests. I reduced the average HTTP response time by 20ms by caching the subscribe metods:

private static final ConcurrentMap<Class<?>, List<Method>> class2SubscribeMethod = new ConcurrentHashMap<Class<?>, List<Method>>();

@Override
public void onBeforeRender(Component component)
{
for (Method curMethod : getSubscribeMethods(component.getClass()))

{ subscribeComponent(component, null, curMethod); }

for (Behavior curBehavior : component.getBehaviors())
{
for (Method curMethod : getSubscribeMethods(curBehavior.getClass()))

{ subscribeComponent(component, curBehavior, curMethod); }

}
}

private List<Method> getSubscribeMethods(Class<?> clazz)
{
List<Method> methods = class2SubscribeMethod.get(clazz);
if (methods != null)

{ return methods; }

methods = computeSubscribeMethods(clazz);
List<Method> newMethods = class2SubscribeMethod.putIfAbsent(clazz, methods);
return newMethods != null ? newMethods : methods;
}

private List<Method> computeSubscribeMethods(Class<?> clazz)
{
List<Method> result = Lists.newArrayList();
for (Method curMethod : clazz.getMethods())
{
if (curMethod.isAnnotationPresent(Subscribe.class))

{ verifyMethodParameters(curMethod); result.add(curMethod); }

}
return result;
}

I can provide a patch of a pull request if needed.