add more soft and weak references to reduce chance of memory leaks

kwebio · May 26, 2023 · a3657a9 · a3657a9
1 parent 191eedf
commit a3657a9
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Showing 3 changed files with 12 additions and 6 deletions.
diff --git a/api/kweb-core.api b/api/kweb-core.api
@@ -1850,7 +1850,7 @@ public class kweb/state/KVal : java/lang/AutoCloseable {
 	public final fun close (Lkweb/state/CloseReason;)V
 	protected final fun finalize ()V
 	protected final fun getCloseReason ()Lkweb/state/CloseReason;
-	protected final fun getListeners ()Ljava/util/concurrent/ConcurrentHashMap;
+	protected final fun getListeners ()Lcom/google/common/cache/Cache;
 	public fun getValue ()Ljava/lang/Object;
 	public final fun map (Lkotlin/jvm/functions/Function1;)Lkweb/state/KVal;
 	public final fun onClose (Lkotlin/jvm/functions/Function0;)V

diff --git a/src/main/kotlin/kweb/state/KVal.kt b/src/main/kotlin/kweb/state/KVal.kt
@@ -1,5 +1,7 @@
 package kweb.state
 
+import com.google.common.cache.Cache
+import com.google.common.cache.CacheBuilder
 import kweb.util.random
 import mu.two.KotlinLogging
 import java.util.concurrent.ConcurrentHashMap
@@ -18,7 +20,11 @@ open class KVal<T : Any?>(value: T) : AutoCloseable{
 
     internal val isClosed get() = closeReason != null
 
-    protected val listeners = ConcurrentHashMap<Long, (T, T) -> Unit>()
+    protected val listeners : Cache<Long, (T, T) -> Unit> = CacheBuilder.newBuilder()
+        // A listener shouldn't cause data to be retained that wouldn't otherwise be
+        // retained
+        .softValues()
+        .build()
     private val closeHandlers = ConcurrentLinkedDeque<() -> Unit>()
 
     /**
@@ -27,7 +33,7 @@ open class KVal<T : Any?>(value: T) : AutoCloseable{
     fun addListener(listener: (T, T) -> Unit): Long {
         verifyNotClosed("add a listener")
         val handle = random.nextLong()
-        listeners[handle] = listener
+        listeners.put(handle, listener)
         return handle
     }
 
@@ -50,7 +56,7 @@ open class KVal<T : Any?>(value: T) : AutoCloseable{
      * changes.
      */
     fun removeListener(handle: Long) {
-        listeners.remove(handle)
+        listeners.invalidate(handle)
     }
 
     /**
@@ -70,7 +76,7 @@ open class KVal<T : Any?>(value: T) : AutoCloseable{
                     logger.debug("Updating mapped $value to $new")
                     val mappedValue = mapper(new)
                     mappedKVal.pValue = mappedValue
-                    mappedKVal.listeners.values.forEach { listener ->
+                    mappedKVal.listeners.asMap().values.forEach { listener ->
                         try {
                             val mappedOld = mapper(old)
                             if (mappedOld != mappedValue) {

diff --git a/src/main/kotlin/kweb/state/KVar.kt b/src/main/kotlin/kweb/state/KVar.kt
@@ -28,7 +28,7 @@ class KVar<T : Any?>(initialValue: T) : KVal<T>(initialValue) {
     override var value: T by Delegates.observable(initialValue) { _, old, new ->
         if (old != new) {
             verifyNotClosed("modify KVar.value")
-            listeners.values.forEach { listener ->
+            listeners.asMap().values.forEach { listener ->
                 try {
                     listener(old, new)
                 } catch (e: Exception) {