Memory Pruning: Only keeping 1000 messages per channel

app/src/main/java/com/vitorpamplona/amethyst/ServiceManager.kt

@@ -1,6 +1,7 @@
 package com.vitorpamplona.amethyst
 
 import com.vitorpamplona.amethyst.model.Account
+import com.vitorpamplona.amethyst.model.LocalCache
 import com.vitorpamplona.amethyst.service.relays.Constants
 import com.vitorpamplona.amethyst.service.NostrAccountDataSource
 import com.vitorpamplona.amethyst.service.NostrChannelDataSource
@@ -66,4 +67,12 @@ object ServiceManager {
     Client.disconnect()
   }
 
+  fun cleanUp() {
+    LocalCache.cleanObservers()
+
+    account?.let {
+      LocalCache.pruneOldAndHiddenMessages(it)
+    }
+  }
+
 }

app/src/main/java/com/vitorpamplona/amethyst/model/Channel.kt

@@ -4,6 +4,7 @@ import androidx.lifecycle.LiveData
 import com.vitorpamplona.amethyst.service.NostrSingleChannelDataSource
 import com.vitorpamplona.amethyst.service.NostrSingleEventDataSource
 import com.vitorpamplona.amethyst.service.model.ChannelCreateEvent
+import com.vitorpamplona.amethyst.ui.dal.ChannelFeedFilter
 import com.vitorpamplona.amethyst.ui.note.toShortenHex
 import fr.acinq.secp256k1.Hex
 import java.util.concurrent.ConcurrentHashMap
@@ -53,6 +54,23 @@ class Channel(val idHex: String) {
     private fun refreshObservers() {
         live.refresh()
     }
+
+    fun pruneOldAndHiddenMessages(account: Account): Set<Note> {
+        val important = notes.values
+            .filter { it.author?.let { it1 -> account.isHidden(it1) } == false }
+            .sortedBy { it.event?.createdAt }
+            .reversed()
+            .take(1000)
+            .toSet()
+
+        val toBeRemoved = notes.values.filter { it in important }.toSet()
+
+        toBeRemoved.forEach {
+            notes.remove(it.idHex)
+        }
+
+        return toBeRemoved
+    }
 }
 
 

app/src/main/java/com/vitorpamplona/amethyst/model/LocalCache.kt

@@ -544,6 +544,29 @@ object LocalCache {
     }
   }
 
+  fun cleanObservers() {
+    notes.forEach {
+      it.value.clearLive()
+    }
+
+    users.forEach {
+      it.value.clearLive()
+    }
+  }
+
+  fun pruneOldAndHiddenMessages(account: Account) {
+    channels.forEach {
+      val toBeRemoved = it.value.pruneOldAndHiddenMessages(account)
+
+      toBeRemoved.forEach {
+        notes.remove(it.idHex)
+        // Doesn't need to clean up the replies and mentions.. Too small to matter.
+      }
+
+      println("PRUNE: ${toBeRemoved.size} messages removed from ${it.value.info.name}")
+    }
+  }
+
   // Observers line up here.
   val live: LocalCacheLiveData = LocalCacheLiveData(this)
 

app/src/main/java/com/vitorpamplona/amethyst/model/User.kt

@@ -363,3 +363,4 @@ class UserLiveData(val user: User): LiveData<UserState>(UserState(user)) {
 }
 
 class UserState(val user: User)
+

app/src/main/java/com/vitorpamplona/amethyst/service/NostrChatroomListDataSource.kt

@@ -38,7 +38,7 @@ object NostrChatroomListDataSource: NostrDataSource("MailBoxFeed") {
   )
 
   fun createMyChannelsFilter() = TypedFilter(
-    types = setOf(FeedType.PUBLIC_CHATS),
+    types = FeedType.values().toSet(), // Metadata comes from any relay
       filter = JsonFilter(
       kinds = listOf(ChannelCreateEvent.kind),
       ids = account.followingChannels.toList()
@@ -48,7 +48,7 @@ object NostrChatroomListDataSource: NostrDataSource("MailBoxFeed") {
   fun createLastChannelInfoFilter(): List<TypedFilter> {
     return account.followingChannels.map {
       TypedFilter(
-        types = setOf(FeedType.PUBLIC_CHATS),
+        types = FeedType.values().toSet(), // Metadata comes from any relay
         filter = JsonFilter(
           kinds = listOf(ChannelMetadataEvent.kind),
           tags = mapOf("e" to listOf(it)),

app/src/main/java/com/vitorpamplona/amethyst/ui/MainActivity.kt

@@ -1,5 +1,6 @@
 package com.vitorpamplona.amethyst.ui
 
+import android.content.ComponentCallbacks2
 import android.net.Uri
 import android.os.Build.VERSION.SDK_INT
 import android.os.Bundle
@@ -22,6 +23,7 @@ import coil.util.DebugLogger
 import com.vitorpamplona.amethyst.EncryptedStorage
 import com.vitorpamplona.amethyst.LocalPreferences
 import com.vitorpamplona.amethyst.ServiceManager
+import com.vitorpamplona.amethyst.model.LocalCache
 import com.vitorpamplona.amethyst.model.decodePublicKey
 import com.vitorpamplona.amethyst.model.toHexKey
 import com.vitorpamplona.amethyst.service.Nip19
@@ -85,4 +87,14 @@ class MainActivity : ComponentActivity() {
 
     super.onPause()
   }
+
+  /**
+   * Release memory when the UI becomes hidden or when system resources become low.
+   * @param level the memory-related event that was raised.
+   */
+  override fun onTrimMemory(level: Int) {
+    super.onTrimMemory(level)
+    println("Trim Memory $level")
+    ServiceManager.cleanUp()
+  }
 }