Handler Caching #37
@ -90,6 +90,16 @@ public final class EventBus {
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*/
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*/
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private final Map<Class<?>, TreeSet<EventHandler>> bindings = new ConcurrentHashMap<>();
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private final Map<Class<?>, TreeSet<EventHandler>> bindings = new ConcurrentHashMap<>();
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/**
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* A cache mapping an event class to all handlers the event should be dispatched to. This
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* includes polymorphic handlers that don't reference the event class explicitly. If an event
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* class is not contained inside this cache, the {@link #bindings} have to be traversed manually
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* in search of applicable handlers.
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*
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* @since 1.3.0
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*/
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private final Map<Class<?>, TreeSet<EventHandler>> bindingCache = new ConcurrentHashMap<>();
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/**
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/**
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* Stores all registered event listeners (which declare event handlers) and prevents them from
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* Stores all registered event listeners (which declare event handlers) and prevents them from
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* being garbage collected.
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* being garbage collected.
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@ -175,24 +185,29 @@ public final class EventBus {
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* Searches for the event handlers bound to an event class. This includes polymorphic handlers
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* Searches for the event handlers bound to an event class. This includes polymorphic handlers
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* that are bound to a supertype of the event class.
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* that are bound to a supertype of the event class.
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*
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*
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* @implNote If the given event type was requested in the past, the handlers are retrieved from
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* the {@link #bindingCache}. If not, the entire {@link #bindings} are traversed in
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* search of polymorphic handlers compatible with the event type.
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* @param eventType the event type to use for the search
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* @param eventType the event type to use for the search
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* @return a navigable set containing the applicable handlers in descending order of priority
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* @return a navigable set containing the applicable handlers in descending order of priority
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* @since 1.2.0
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* @since 1.2.0
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*/
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*/
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private NavigableSet<EventHandler> getHandlersFor(Class<?> eventType) {
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private NavigableSet<EventHandler> getHandlersFor(Class<?> eventType) {
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return bindingCache.computeIfAbsent(eventType, k -> {
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// Get handlers defined for the event class
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// Get handlers defined for the event class
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TreeSet<EventHandler> handlers =
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TreeSet<EventHandler> handlers =
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bindings.getOrDefault(eventType, new TreeSet<>(byPriority));
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bindings.getOrDefault(eventType, new TreeSet<>(byPriority));
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// Get polymorphic handlers
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// Get polymorphic handlers
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for (var binding : bindings.entrySet())
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for (var binding : bindings.entrySet())
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if (binding.getKey().isAssignableFrom(eventType))
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if (binding.getKey().isAssignableFrom(eventType))
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for (var handler : binding.getValue())
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for (var handler : binding.getValue())
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if (handler.isPolymorphic())
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if (handler.isPolymorphic())
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handlers.add(handler);
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handlers.add(handler);
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return handlers;
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return handlers;
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});
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}
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}
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/**
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/**
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@ -369,15 +384,28 @@ public final class EventBus {
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}
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}
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/**
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/**
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* Inserts a new handler into the {@link #bindings} map.
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* Inserts a new handler into the {@link #bindings} map. Additionally, the handler is placed
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* inside the {@link #bindingCache} where applicable.
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*
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*
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* @param handler the handler to bind
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* @param handler the handler to bind
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* @since 1.2.0
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* @since 1.2.0
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*/
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*/
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private void bindHandler(EventHandler handler) {
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private void bindHandler(EventHandler handler) {
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bindings.putIfAbsent(handler.getEventType(), new TreeSet<>(byPriority));
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// Bind handler
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logger.log(Level.DEBUG, "Binding event handler {0}", handler);
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logger.log(Level.DEBUG, "Binding event handler {0}", handler);
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bindings.get(handler.getEventType()).add(handler);
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bindings.computeIfAbsent(handler.getEventType(), k -> new TreeSet<>(byPriority))
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.add(handler);
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// Insert handler into cache
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bindingCache.computeIfAbsent(handler.getEventType(), k -> new TreeSet<>(byPriority))
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.add(handler);
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// Handler is polymorphic => insert where applicable
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if (handler.isPolymorphic())
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for (var binding : bindingCache.entrySet())
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if (binding.getKey().isAssignableFrom(handler.getEventType()))
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binding.getValue().add(handler);
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}
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}
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/**
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/**
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@ -395,13 +423,25 @@ public final class EventBus {
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var it = binding.iterator();
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var it = binding.iterator();
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while (it.hasNext()) {
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while (it.hasNext()) {
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var handler = it.next();
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var handler = it.next();
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if (handler.getListener() == listener) {
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if (handler.getListener().equals(listener)) {
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logger.log(Level.DEBUG, "Unbinding event handler {0}", handler);
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logger.log(Level.DEBUG, "Unbinding event handler {0}", handler);
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it.remove();
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it.remove();
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}
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}
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}
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}
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}
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}
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// Remove bindings from cache
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for (var binding : bindingCache.values()) {
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var it = binding.iterator();
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while (it.hasNext()) {
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var handler = it.next();
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if (handler.getListener().equals(listener)) {
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logger.log(Level.TRACE, "Removing event handler {0} from cache", handler);
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it.remove();
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}
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}
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}
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// Remove the listener itself
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// Remove the listener itself
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registeredListeners.remove(listener);
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registeredListeners.remove(listener);
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}
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}
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@ -414,6 +454,7 @@ public final class EventBus {
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public void clearListeners() {
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public void clearListeners() {
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logger.log(Level.INFO, "Clearing event listeners");
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logger.log(Level.INFO, "Clearing event listeners");
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bindings.clear();
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bindings.clear();
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bindingCache.clear();
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registeredListeners.clear();
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registeredListeners.clear();
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}
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}
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@ -14,8 +14,7 @@ import org.junit.jupiter.api.*;
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@Priority(150)
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@Priority(150)
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class DispatchTest {
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class DispatchTest {
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EventBus bus;
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EventBus bus;
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static int hits;
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/**
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/**
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* Constructs an event bus and registers this test instance as an event listener.
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* Constructs an event bus and registers this test instance as an event listener.
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@ -27,8 +26,8 @@ class DispatchTest {
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bus = new EventBus();
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bus = new EventBus();
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bus.registerListener(this);
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bus.registerListener(this);
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bus.registerListener(SimpleEvent.class, e -> {
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bus.registerListener(SimpleEvent.class, e -> {
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++hits;
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e.increment();
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assertEquals(4, hits);
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assertEquals(3, e.getCounter());
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});
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});
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}
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}
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@ -51,29 +50,39 @@ class DispatchTest {
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*/
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*/
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@Test
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@Test
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void testDebugExecutionOrder() {
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void testDebugExecutionOrder() {
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String executionOrder = bus.debugExecutionOrder(SimpleEvent.class);
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System.out.println(executionOrder);
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assertEquals(
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assertEquals(
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"Event handler execution order for class dev.kske.eventbus.core.SimpleEvent (3 handler(s)):\n"
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"Event handler execution order for class dev.kske.eventbus.core.SimpleEvent (3 handler(s)):\n"
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+ "==========================================================================================\n"
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+ "==========================================================================================\n"
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+ "ReflectiveEventHandler[eventType=class dev.kske.eventbus.core.SimpleEvent, polymorphic=true, priority=200, method=void dev.kske.eventbus.core.DispatchTest.onSimpleEventFirst(), useParameter=false]\n"
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+ "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"
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+ "ReflectiveEventHandler[eventType=class dev.kske.eventbus.core.SimpleEvent, polymorphic=false, priority=150, method=static void dev.kske.eventbus.core.DispatchTest.onSimpleEventSecond(), useParameter=false]\n"
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+ "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"
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+ "CallbackEventHandler[eventType=class dev.kske.eventbus.core.SimpleEvent, polymorphic=false, priority=100]\n"
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+ "CallbackEventHandler[eventType=class dev.kske.eventbus.core.SimpleEvent, polymorphic=false, priority=100]\n"
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+ "==========================================================================================",
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+ "==========================================================================================",
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executionOrder);
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bus.debugExecutionOrder(SimpleEvent.class));
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}
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}
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@Event(SimpleEvent.class)
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/**
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* Tests whether the handlers bound to an event type are correct when retrieved from the binding
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* cache. On the second call of {@link EventBus#debugExecutionOrder(Class)} the cache is used.
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*
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* @since 1.3.0
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*/
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@Test
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void testBindingCache() {
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assertEquals(bus.debugExecutionOrder(SimpleEventSub.class),
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bus.debugExecutionOrder(SimpleEventSub.class));
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}
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kske marked this conversation as resolved
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@Event
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@Priority(200)
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@Priority(200)
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void onSimpleEventFirst() {
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void onSimpleEventFirst(SimpleEvent event) {
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++hits;
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event.increment();
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assertTrue(hits == 1 || hits == 2);
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assertTrue(event.getCounter() == 1 || event.getCounter() == 2);
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}
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}
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@Event(SimpleEvent.class)
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@Event
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@Polymorphic(false)
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@Polymorphic(false)
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static void onSimpleEventSecond() {
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static void onSimpleEventSecond(SimpleEvent event) {
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++hits;
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event.increment();
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assertEquals(3, hits);
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assertEquals(2, event.getCounter());
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}
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}
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}
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}
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@ -14,7 +14,7 @@ class SimpleEvent {
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@Override
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@Override
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public String toString() {
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public String toString() {
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return String.format("SimpleEvent[%d]", counter);
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return String.format("%s[%d]", getClass().getSimpleName(), counter);
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}
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}
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void increment() {
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void increment() {
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|
Loading…
Reference in New Issue
Block a user
Why?