feat: LocalEvent optimize

Signed-off-by: Hu Shenghao <[email protected]>

basic/src/main/java/com/dede/android_eggs/util/GcWatcher.kt

@@ -0,0 +1,50 @@
+package com.dede.android_eggs.util
+
+import java.lang.ref.WeakReference
+
+/**
+ * GC Watcher
+ * 
+ * @see [com.android.internal.os.BinderInternal]
+ */
+class GcWatcher private constructor() {
+
+    companion object {
+
+        private val sInstance = GcWatcher()
+
+        private val sGcWatchers: ArrayList<Runnable> = ArrayList()
+        private var sTempWatchers: Array<Runnable?> = emptyArray()
+
+        private var sGcWatcherRef: WeakReference<GcWatcherObj> = WeakReference(GcWatcherObj())
+
+        fun get(): GcWatcher {
+            return sInstance
+        }
+    }
+
+    @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN")
+    private class GcWatcherObj : Object() {
+        override fun finalize() {
+            synchronized(sGcWatchers) {
+                sTempWatchers = sGcWatchers.toArray(sTempWatchers)
+            }
+            for (gcWatcher in sTempWatchers) {
+                gcWatcher?.run()
+            }
+            sGcWatcherRef = WeakReference(GcWatcherObj())
+        }
+    }
+
+    fun addWatcher(watcher: Runnable) {
+        synchronized(sGcWatchers) {
+            sGcWatchers.add(watcher)
+        }
+    }
+
+    fun removeWatcher(watcher: Runnable) {
+        synchronized(sGcWatchers) {
+            sGcWatchers.remove(watcher)
+        }
+    }
+}

basic/src/main/java/com/dede/android_eggs/util/LocalEvent.kt

@@ -2,6 +2,7 @@ package com.dede.android_eggs.util
 
 import android.content.Intent
 import android.os.Bundle
+import android.util.Log
 import androidx.lifecycle.LifecycleOwner
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.Observer
@@ -24,6 +25,23 @@ object LocalEvent {
         return liveData
     }
 
+    init {
+        GcWatcher.get().addWatcher { trim() }
+    }
+
+    private fun trim() {
+        var count = 0
+        val keys = localEventLiveDataMap.keys
+        for (key in keys) {
+            val liveData = localEventLiveDataMap[key] ?: continue
+            if (!liveData.hasObservers()) {
+                localEventLiveDataMap.remove(key)
+                count++
+            }
+        }
+        Log.i("LocalEvent", "trim: %d".format(count))
+    }
+
     fun poster(): Poster {
         return Poster()
     }