From 790cbb35db9d170dca3e8c9e2ffe5b79efa820c6 Mon Sep 17 00:00:00 2001
From: Vitor Pamplona <vitor@vitorpamplona.com>
Date: Tue, 14 Feb 2023 09:29:24 -0500
Subject: [PATCH] Moving Database updates to an invalidate UI call that only
 runs at every 100 ms.

---
 .../amethyst/model/LocalCache.kt              | 28 +++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/app/src/main/java/com/vitorpamplona/amethyst/model/LocalCache.kt b/app/src/main/java/com/vitorpamplona/amethyst/model/LocalCache.kt
index 87d95204a..e9e1f6ecd 100644
--- a/app/src/main/java/com/vitorpamplona/amethyst/model/LocalCache.kt
+++ b/app/src/main/java/com/vitorpamplona/amethyst/model/LocalCache.kt
@@ -22,6 +22,12 @@ import java.time.format.DateTimeFormatter
 import java.util.Collections
 import java.util.concurrent.ConcurrentHashMap
 import com.vitorpamplona.amethyst.service.relays.Relay
+import java.util.concurrent.atomic.AtomicBoolean
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
 import nostr.postr.events.ContactListEvent
 import nostr.postr.events.DeletionEvent
 import nostr.postr.events.Event
@@ -502,12 +508,30 @@ object LocalCache {
   val live: LocalCacheLiveData = LocalCacheLiveData(this)
 
   private fun refreshObservers() {
-    live.refresh()
+    live.invalidateData()
   }
 }
 
 class LocalCacheLiveData(val cache: LocalCache): LiveData<LocalCacheState>(LocalCacheState(cache)) {
-  fun refresh() {
+
+  // Refreshes observers in batches.
+  var handlerWaiting = AtomicBoolean()
+
+  @Synchronized
+  fun invalidateData() {
+    if (!hasActiveObservers()) return
+    if (handlerWaiting.getAndSet(true)) return
+
+    handlerWaiting.set(true)
+    val scope = CoroutineScope(Job() + Dispatchers.Main)
+    scope.launch {
+      delay(100)
+      refresh()
+      handlerWaiting.set(false)
+    }
+  }
+
+  private fun refresh() {
     postValue(LocalCacheState(cache))
   }
 }