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-rw-r--r--src/main/kotlin/me/bush/illnamethislater/CancelledState.kt20
-rw-r--r--src/main/kotlin/me/bush/illnamethislater/Config.kt24
-rw-r--r--src/main/kotlin/me/bush/illnamethislater/EventBus.kt41
-rw-r--r--src/main/kotlin/me/bush/illnamethislater/Listener.kt8
-rw-r--r--src/main/kotlin/me/bush/illnamethislater/ListenerGroup.kt63
5 files changed, 110 insertions, 46 deletions
diff --git a/src/main/kotlin/me/bush/illnamethislater/CancelledState.kt b/src/main/kotlin/me/bush/illnamethislater/CancelledState.kt
index ed2263a..87846c7 100644
--- a/src/main/kotlin/me/bush/illnamethislater/CancelledState.kt
+++ b/src/main/kotlin/me/bush/illnamethislater/CancelledState.kt
@@ -1,7 +1,9 @@
package me.bush.illnamethislater
import sun.misc.Unsafe
+import java.lang.reflect.Modifier
import kotlin.reflect.KClass
+import kotlin.reflect.KMutableProperty
import kotlin.reflect.KMutableProperty1
import kotlin.reflect.full.declaredMembers
import kotlin.reflect.full.isSubclassOf
@@ -22,8 +24,6 @@ internal fun interface CancelledState {
*/
fun isCancelled(event: Any): Boolean
- // Maybe move this to eventbus or util? todo
- // Make CancelledState a class? todo
companion object {
private val UNSAFE = Unsafe::class.declaredMembers.single { it.name == "theUnsafe" }.handleCall() as Unsafe
private val CANCELLED_NAMES = arrayOf("canceled", "cancelled")
@@ -33,19 +33,21 @@ internal fun interface CancelledState {
/**
* Creates a [CancelledState] object for events of class [type].
*/
- // TODO: 3/31/2022 static/singleton fields
fun of(type: KClass<*>, config: Config): CancelledState {
- // Default impl for our event class
+ // Default impl for our event class.
if (type.isSubclassOf(Event::class)) return CancelledState { (it as Event).cancelled }
- // If compat is disabled
+ // If compat is disabled.
if (!config.thirdPartyCompatibility) return NOT_CANCELLABLE
- // Find a field named "cancelled" or "canceled"
+ // Find a field named "cancelled" or "canceled" that is a boolean, and has a backing field.
type.allMembers.filter { it.name in CANCELLED_NAMES && it.returnType == typeOf<Boolean>() }
- .filterIsInstance<KMutableProperty1<*, *>>().toList().let {
+ .filterIsInstance<KMutableProperty<*>>().filter { it.javaField != null }.toList().let {
if (it.isEmpty()) return NOT_CANCELLABLE
if (it.size != 1) config.logger.warn("Multiple possible cancel fields found for event type $type")
- OFFSETS[type] = UNSAFE.objectFieldOffset(it[0].javaField)
- // This is not using reflection, and it is the same speed as direct access.
+ it[0].javaField!!.let { field ->
+ if (Modifier.isStatic(field.modifiers)) OFFSETS[type] = UNSAFE.staticFieldOffset(field)
+ else OFFSETS[type] = UNSAFE.objectFieldOffset(field)
+ }
+ // This is the same speed as direct access, plus one JNI call and hashmap access.
// If you are familiar with C, this is essentially the same idea as pointers.
return CancelledState { event -> UNSAFE.getBoolean(event, OFFSETS[type]!!) }
}
diff --git a/src/main/kotlin/me/bush/illnamethislater/Config.kt b/src/main/kotlin/me/bush/illnamethislater/Config.kt
index eb9ccf5..ef946c5 100644
--- a/src/main/kotlin/me/bush/illnamethislater/Config.kt
+++ b/src/main/kotlin/me/bush/illnamethislater/Config.kt
@@ -1,7 +1,9 @@
package me.bush.illnamethislater
+import kotlinx.coroutines.Dispatchers
import org.apache.logging.log4j.LogManager
import org.apache.logging.log4j.Logger
+import kotlin.coroutines.CoroutineContext
/**
@@ -15,15 +17,33 @@ import org.apache.logging.log4j.Logger
data class Config(
/**
- * The logger this [EventBus] will use to log errors, or [EventBus.debugInfo]
+ * The logger this [EventBus] will use to log errors, or log [EventBus.debugInfo]
*/
val logger: Logger = LogManager.getLogger("Eventbus"),
/**
+ * The [CoroutineContext] to use when posting events to parallel listeners. The default
+ * value will work just fine, but you can specify a custom context if desired.
+ *
+ * [What is a Coroutine Context?](https://kotlinlang.org/docs/coroutine-context-and-dispatchers.html)
+ *
+ * [Information and examples](https://github.com/therealbush/eventbus-kotlin#tododothething)
+ */
+ val parallelContext: CoroutineContext = Dispatchers.Default,
+
+ /**
* Whether this [EventBus] should try to find a "cancelled" field in events being listened for that
* are not a subclass of [Event]. This is experimental, and should be set to `false` if problems arise.
*
* [Information and examples](https://github.com/therealbush/eventbus-kotlin#tododothething)
*/
- val thirdPartyCompatibility: Boolean = true
+ val thirdPartyCompatibility: Boolean = true,
+
+ /**
+ * Whether parallel listeners should be called before or after sequential listeners. Parallel listeners
+ * will always finish before sequential listeners are called, or before [EventBus.post] returns.
+ *
+ * [Information and examples](https://github.com/therealbush/eventbus-kotlin#tododothething)
+ */
+ val parallelFirst: Boolean = true
)
diff --git a/src/main/kotlin/me/bush/illnamethislater/EventBus.kt b/src/main/kotlin/me/bush/illnamethislater/EventBus.kt
index 90ec395..6b9b0bf 100644
--- a/src/main/kotlin/me/bush/illnamethislater/EventBus.kt
+++ b/src/main/kotlin/me/bush/illnamethislater/EventBus.kt
@@ -2,17 +2,15 @@ package me.bush.illnamethislater
import kotlin.reflect.KClass
-// TODO: 3/30/2022 Refactor some stuff
-
/**
- * [A simple event dispatcher](http://github.com/therealbush/eventbus-kotlin)
+ * A simple event dispatcher
+ *
+ * [Information and examples](https://github.com/therealbush/eventbus-kotlin#tododothething)
*
* @author bush
* @since 1.0.0
*/
-class EventBus(
- private val config: Config = Config()
-) {
+class EventBus(private val config: Config = Config()) {
private val listeners = hashMapOf<KClass<*>, ListenerGroup>()
private val subscribers = mutableSetOf<Any>()
@@ -29,7 +27,7 @@ class EventBus(
it.subscriber = subscriber
})
}
- subscribers += subscriber
+ subscribers.add(subscriber)
true
}.getOrElse {
config.logger.error("Unable to register listeners for subscriber $subscriber", it)
@@ -38,19 +36,6 @@ class EventBus(
}
/**
- * Registers a listener (which may not belong to any subscriber) to this [EventBus]. If no object
- * is given, a key will be returned which can be used in [unsubscribe] to remove the listener.
- *
- * [Information and examples](https://github.com/therealbush/eventbus-kotlin#tododothething)
- */
- fun register(listener: Listener): Listener {
- listeners.computeIfAbsent(listener.type) {
- ListenerGroup(it, config)
- }.add(listener)
- return listener
- }
-
- /**
* doc
*
* [Information and examples](https://github.com/therealbush/eventbus-kotlin#tododothething)
@@ -58,18 +43,30 @@ class EventBus(
fun unsubscribe(subscriber: Any): Boolean {
return subscribers.remove(subscriber).also { contains ->
if (contains) listeners.entries.removeIf {
- it.value.removeFrom(subscriber)
+ it.value.unsubscribe(subscriber)
it.value.sequential.isEmpty() && it.value.parallel.isEmpty()
}
}
}
/**
+ * Registers a listener (which may not belong to any subscriber) to this [EventBus]. If no object
+ * is given, a key will be returned which can be used in [unsubscribe] to remove the listener.
+ *
+ * [Information and examples](https://github.com/therealbush/eventbus-kotlin#tododothething)
+ */
+ fun register(listener: Listener) = listener.also {
+ listeners.computeIfAbsent(it.type) { type -> ListenerGroup(type, config) }.register(it)
+ }
+
+ /**
* doc
*
* [Information and examples](https://github.com/therealbush/eventbus-kotlin#tododothething)
*/
- fun unregister(listener: Listener) = listeners[listener.type]?.remove(listener) ?: false
+ fun unregister(listener: Listener) = listener.also {
+ listeners[it.type]?.unregister(it)
+ }
/**
* Posts an event. doc
diff --git a/src/main/kotlin/me/bush/illnamethislater/Listener.kt b/src/main/kotlin/me/bush/illnamethislater/Listener.kt
index 2d96d54..7105baf 100644
--- a/src/main/kotlin/me/bush/illnamethislater/Listener.kt
+++ b/src/main/kotlin/me/bush/illnamethislater/Listener.kt
@@ -14,15 +14,15 @@ import kotlin.reflect.KClass
class Listener @PublishedApi internal constructor(
listener: (Nothing) -> Unit,
internal val type: KClass<*>,
- internal var priority: Int = 0,
- internal var parallel: Boolean = false,
- internal var receiveCancelled: Boolean = false
+ internal val priority: Int = 0,
+ internal val parallel: Boolean = false,
+ internal val receiveCancelled: Boolean = false
) {
@Suppress("UNCHECKED_CAST")
// Generics have no benefit here,
// it is easier just to force cast.
internal val listener = listener as (Any) -> Unit
- internal lateinit var subscriber: Any
+ internal var subscriber: Any? = null
}
/**
diff --git a/src/main/kotlin/me/bush/illnamethislater/ListenerGroup.kt b/src/main/kotlin/me/bush/illnamethislater/ListenerGroup.kt
index 56b5421..9c8714b 100644
--- a/src/main/kotlin/me/bush/illnamethislater/ListenerGroup.kt
+++ b/src/main/kotlin/me/bush/illnamethislater/ListenerGroup.kt
@@ -1,9 +1,13 @@
package me.bush.illnamethislater
+import kotlinx.coroutines.*
import java.util.concurrent.CopyOnWriteArrayList
+import kotlin.coroutines.CoroutineContext
import kotlin.reflect.KClass
/**
+ * A class for storing and handling listeners.
+ *
* @author bush
* @since 1.0.0
*/
@@ -11,29 +15,70 @@ internal class ListenerGroup(
private val type: KClass<*>,
private val config: Config
) {
- val cancelledState = CancelledState.of(type, config)
+ private val cancelledState = CancelledState.of(type, config)
val sequential = CopyOnWriteArrayList<Listener>()
val parallel = CopyOnWriteArrayList<Listener>()
- fun add(listener: Listener) {
+ /**
+ * Adds [listener] to this [ListenerGroup], and sorts its list.
+ */
+ fun register(listener: Listener) {
with(if (listener.parallel) parallel else sequential) {
add(listener)
- sortBy { it.priority }
+ sortedByDescending { it.priority }
}
}
- fun remove(listener: Listener) = with(if (listener.parallel) parallel else sequential) {
- remove(listener)
+ /**
+ * Removes [listener] from this [ListenerGroup].
+ */
+ fun unregister(listener: Listener) {
+ if (listener.parallel) parallel.remove(listener)
+ else sequential.remove(listener)
}
- fun removeFrom(subscriber: Any) {
- parallel.removeIf(Listener::subscriber::equals)
- sequential.removeIf(Listener::subscriber::equals)
+ /**
+ * Removes every listener whose subscriber is [subscriber].
+ */
+ fun unsubscribe(subscriber: Any) {
+ parallel.removeIf { it.subscriber == subscriber }
+ sequential.removeIf { it.subscriber == subscriber }
}
+ /**
+ * Posts an event to every listener. Returns true of the event was cancelled.
+ */
fun post(event: Any): Boolean {
- return false
+ if (config.parallelFirst) postParallel(event)
+ sequential.forEach {
+ if (it.receiveCancelled || !cancelledState.isCancelled(event)) {
+ it.listener(event)
+ }
+ }
+ if (!config.parallelFirst) postParallel(event)
+ return cancelledState.isCancelled(event)
+ }
+
+ /**
+ * Posts an event to all parallel listeners. Cancel state of the event is checked once before
+ * posting the event as opposed to before calling each listener, to avoid inconsistencies.
+ */
+ private fun postParallel(event: Any) {
+ if (parallel.isEmpty()) return
+ // We check this once, because listener order is not consistent
+ val cancelled = cancelledState.isCancelled(event)
+ // Credit to KB for the idea
+ runBlocking(config.parallelContext) {
+ parallel.forEach {
+ if (it.receiveCancelled || !cancelled) launch {
+ it.listener(event)
+ }
+ }
+ }
}
+ /**
+ * Logs information about this [ListenerGroup].
+ */
fun debugInfo() = config.logger.info("${type.simpleName}: ${sequential.size}, ${parallel.size}")
}