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Merge pull request 'Handler Caching' (#37) from f/handler-caching into develop

Reviewed-on: #37
Reviewed-by: delvh <leon@kske.dev>
develop
kske 4 months ago
parent
commit
cc5c07079a
Signed by: KSKE Git
GPG Key ID: 70F2F9206EDC1FCE
  1. 69
      core/src/main/java/dev/kske/eventbus/core/EventBus.java
  2. 43
      core/src/test/java/dev/kske/eventbus/core/DispatchTest.java
  3. 2
      core/src/test/java/dev/kske/eventbus/core/SimpleEvent.java

69
core/src/main/java/dev/kske/eventbus/core/EventBus.java

@ -90,6 +90,16 @@ public final class EventBus {
*/
private final Map<Class<?>, TreeSet<EventHandler>> bindings = new ConcurrentHashMap<>();
/**
* A cache mapping an event class to all handlers the event should be dispatched to. This
* includes polymorphic handlers that don't reference the event class explicitly. If an event
* class is not contained inside this cache, the {@link #bindings} have to be traversed manually
* in search of applicable handlers.
*
* @since 1.3.0
*/
private final Map<Class<?>, TreeSet<EventHandler>> bindingCache = new ConcurrentHashMap<>();
/**
* Stores all registered event listeners (which declare event handlers) and prevents them from
* being garbage collected.
@ -175,24 +185,29 @@ public final class EventBus {
* Searches for the event handlers bound to an event class. This includes polymorphic handlers
* that are bound to a supertype of the event class.
*
* @implNote If the given event type was requested in the past, the handlers are retrieved from
* the {@link #bindingCache}. If not, the entire {@link #bindings} are traversed in
* search of polymorphic handlers compatible with the event type.
* @param eventType the event type to use for the search
* @return a navigable set containing the applicable handlers in descending order of priority
* @since 1.2.0
*/
private NavigableSet<EventHandler> getHandlersFor(Class<?> eventType) {
return bindingCache.computeIfAbsent(eventType, k -> {
// Get handlers defined for the event class
TreeSet<EventHandler> handlers =
bindings.getOrDefault(eventType, new TreeSet<>(byPriority));
// Get handlers defined for the event class
TreeSet<EventHandler> handlers =
bindings.getOrDefault(eventType, new TreeSet<>(byPriority));
// Get polymorphic handlers
for (var binding : bindings.entrySet())
if (binding.getKey().isAssignableFrom(eventType))
for (var handler : binding.getValue())
if (handler.isPolymorphic())
handlers.add(handler);
// Get polymorphic handlers
for (var binding : bindings.entrySet())
if (binding.getKey().isAssignableFrom(eventType))
for (var handler : binding.getValue())
if (handler.isPolymorphic())
handlers.add(handler);
return handlers;
return handlers;
});
}
/**
@ -369,15 +384,28 @@ public final class EventBus {
}
/**
* Inserts a new handler into the {@link #bindings} map.
* Inserts a new handler into the {@link #bindings} map. Additionally, the handler is placed
* inside the {@link #bindingCache} where applicable.
*
* @param handler the handler to bind
* @since 1.2.0
*/
private void bindHandler(EventHandler handler) {
bindings.putIfAbsent(handler.getEventType(), new TreeSet<>(byPriority));
// Bind handler
logger.log(Level.DEBUG, "Binding event handler {0}", handler);
bindings.get(handler.getEventType()).add(handler);
bindings.computeIfAbsent(handler.getEventType(), k -> new TreeSet<>(byPriority))
.add(handler);
// Insert handler into cache
bindingCache.computeIfAbsent(handler.getEventType(), k -> new TreeSet<>(byPriority))
.add(handler);
// Handler is polymorphic => insert where applicable
if (handler.isPolymorphic())
for (var binding : bindingCache.entrySet())
if (binding.getKey().isAssignableFrom(handler.getEventType()))
binding.getValue().add(handler);
}
/**
@ -395,13 +423,25 @@ public final class EventBus {
var it = binding.iterator();
while (it.hasNext()) {
var handler = it.next();
if (handler.getListener() == listener) {
if (handler.getListener().equals(listener)) {
logger.log(Level.DEBUG, "Unbinding event handler {0}", handler);
it.remove();
}
}
}
// Remove bindings from cache
for (var binding : bindingCache.values()) {
var it = binding.iterator();
while (it.hasNext()) {
var handler = it.next();
if (handler.getListener().equals(listener)) {
logger.log(Level.TRACE, "Removing event handler {0} from cache", handler);
it.remove();
}
}
}
// Remove the listener itself
registeredListeners.remove(listener);
}
@ -414,6 +454,7 @@ public final class EventBus {
public void clearListeners() {
logger.log(Level.INFO, "Clearing event listeners");
bindings.clear();
bindingCache.clear();
registeredListeners.clear();
}

43
core/src/test/java/dev/kske/eventbus/core/DispatchTest.java

@ -14,8 +14,7 @@ import org.junit.jupiter.api.*;
@Priority(150)
class DispatchTest {
EventBus bus;
static int hits;
EventBus bus;
/**
* Constructs an event bus and registers this test instance as an event listener.
@ -27,8 +26,8 @@ class DispatchTest {
bus = new EventBus();
bus.registerListener(this);
bus.registerListener(SimpleEvent.class, e -> {
++hits;
assertEquals(4, hits);
e.increment();
assertEquals(3, e.getCounter());
});
}
@ -51,29 +50,39 @@ class DispatchTest {
*/
@Test
void testDebugExecutionOrder() {
String executionOrder = bus.debugExecutionOrder(SimpleEvent.class);
System.out.println(executionOrder);
assertEquals(
"Event handler execution order for class dev.kske.eventbus.core.SimpleEvent (3 handler(s)):\n"
+ "==========================================================================================\n"
+ "ReflectiveEventHandler[eventType=class dev.kske.eventbus.core.SimpleEvent, polymorphic=true, priority=200, method=void dev.kske.eventbus.core.DispatchTest.onSimpleEventFirst(), useParameter=false]\n"
+ "ReflectiveEventHandler[eventType=class dev.kske.eventbus.core.SimpleEvent, polymorphic=false, priority=150, method=static void dev.kske.eventbus.core.DispatchTest.onSimpleEventSecond(), useParameter=false]\n"
+ "ReflectiveEventHandler[eventType=class dev.kske.eventbus.core.SimpleEvent, polymorphic=true, priority=200, method=void dev.kske.eventbus.core.DispatchTest.onSimpleEventFirst(dev.kske.eventbus.core.SimpleEvent), useParameter=true]\n"
+ "ReflectiveEventHandler[eventType=class dev.kske.eventbus.core.SimpleEvent, polymorphic=false, priority=150, method=static void dev.kske.eventbus.core.DispatchTest.onSimpleEventSecond(dev.kske.eventbus.core.SimpleEvent), useParameter=true]\n"
+ "CallbackEventHandler[eventType=class dev.kske.eventbus.core.SimpleEvent, polymorphic=false, priority=100]\n"
+ "==========================================================================================",
executionOrder);
bus.debugExecutionOrder(SimpleEvent.class));
}
@Event(SimpleEvent.class)
/**
* Tests whether the handlers bound to an event type are correct when retrieved from the binding
* cache. On the second call of {@link EventBus#debugExecutionOrder(Class)} the cache is used.
*
* @since 1.3.0
*/
@Test
void testBindingCache() {
assertEquals(bus.debugExecutionOrder(SimpleEventSub.class),
bus.debugExecutionOrder(SimpleEventSub.class));
}
@Event
@Priority(200)
void onSimpleEventFirst() {
++hits;
assertTrue(hits == 1 || hits == 2);
void onSimpleEventFirst(SimpleEvent event) {
event.increment();
assertTrue(event.getCounter() == 1 || event.getCounter() == 2);
}
@Event(SimpleEvent.class)
@Event
@Polymorphic(false)
static void onSimpleEventSecond() {
++hits;
assertEquals(3, hits);
static void onSimpleEventSecond(SimpleEvent event) {
event.increment();
assertEquals(2, event.getCounter());
}
}

2
core/src/test/java/dev/kske/eventbus/core/SimpleEvent.java

@ -14,7 +14,7 @@ class SimpleEvent {
@Override
public String toString() {
return String.format("SimpleEvent[%d]", counter);
return String.format("%s[%d]", getClass().getSimpleName(), counter);
}
void increment() {

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