android, desktop: moving chats changing in main thread (#5461)

* android, desktop: moving chats changing in main thread

* modifying chat items in main thread only

* comment

apps/multiplatform/common/src/androidMain/kotlin/chat/simplex/common/platform/UI.android.kt

@@ -14,6 +14,7 @@ import androidx.compose.runtime.*
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.platform.LocalView
 import chat.simplex.common.AppScreen
+import chat.simplex.common.model.ChatModel.withChats
 import chat.simplex.common.model.clear
 import chat.simplex.common.model.clearAndNotify
 import chat.simplex.common.views.helpers.*
@@ -74,9 +75,13 @@ actual class GlobalExceptionsHandler: Thread.UncaughtExceptionHandler {
     if (ModalManager.start.hasModalsOpen()) {
       ModalManager.start.closeModal()
     } else if (chatModel.chatId.value != null) {
-      // Since no modals are open, the problem is probably in ChatView
-      chatModel.chatId.value = null
-      chatModel.chatItems.clearAndNotify()
+      withApi {
+        withChats {
+          // Since no modals are open, the problem is probably in ChatView
+          chatModel.chatId.value = null
+          chatItems.clearAndNotify()
+        }
+      }
     } else {
       // ChatList, nothing to do. Maybe to show other view except ChatList
     }

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/model/ChatModel.kt

@@ -61,7 +61,6 @@ object ChatModel {
   val incompleteInitializedDbRemoved = mutableStateOf(false)
   private val _chats = mutableStateOf(SnapshotStateList<Chat>())
   val chats: State<List<Chat>> = _chats
-  private val chatsContext = ChatsContext()
   // map of connections network statuses, key is agent connection id
   val networkStatuses = mutableStateMapOf<String, NetworkStatus>()
   val switchingUsersAndHosts = mutableStateOf(false)
@@ -72,7 +71,10 @@ object ChatModel {
    * If some helper is missing, create it. Notify is needed to track state of items that we added manually (not via api call). See [apiLoadMessages].
    * If you use api call to get the items, use just [add] instead of [addAndNotify].
    * Never modify underlying list directly because it produces unexpected results in ChatView's LazyColumn (setting by index is ok) */
-  val chatItems = mutableStateOf(SnapshotStateList<ChatItem>())
+  private val _chatItems = mutableStateOf(SnapshotStateList<ChatItem>())
+  val chatItems: State<SnapshotStateList<ChatItem>> = _chatItems
+  // declaration of chatsContext should be after any other variable that is directly attached to ChatsContext class, otherwise, strange crash with NullPointerException for "this" parameter in random functions
+  private val chatsContext = ChatsContext()
   // set listener here that will be notified on every add/delete of a chat item
   var chatItemsChangesListener: ChatItemsChangesListener? = null
   val chatState = ActiveChatState()
@@ -157,7 +159,6 @@ object ChatModel {
   val updatingProgress = mutableStateOf(null as Float?)
   var updatingRequest: Closeable? = null
 
-  private val updatingChatsMutex: Mutex = Mutex()
   val changingActiveUserMutex: Mutex = Mutex()
 
   val desktopNoUserNoRemote: Boolean @Composable get() = appPlatform.isDesktop && currentUser.value == null && currentRemoteHost.value == null
@@ -336,12 +337,14 @@ object ChatModel {
     }
   }
 
-  suspend fun <T> withChats(action: suspend ChatsContext.() -> T): T = updatingChatsMutex.withLock {
+  // running everything inside the block on main thread. Make sure any heavy computation is moved to a background thread
+  suspend fun <T> withChats(action: suspend ChatsContext.() -> T): T = withContext(Dispatchers.Main) {
     chatsContext.action()
   }
 
   class ChatsContext {
     val chats = _chats
+    val chatItems = _chatItems
 
     suspend fun addChat(chat: Chat) {
       chats.add(index = 0, chat)
@@ -762,7 +765,7 @@ object ChatModel {
 
   suspend fun addLiveDummy(chatInfo: ChatInfo): ChatItem {
     val cItem = ChatItem.liveDummy(chatInfo is ChatInfo.Direct)
-    withContext(Dispatchers.Main) {
+    withChats {
       chatItems.addAndNotify(cItem)
     }
     return cItem
@@ -770,7 +773,11 @@ object ChatModel {
 
   fun removeLiveDummy() {
     if (chatItems.value.lastOrNull()?.id == ChatItem.TEMP_LIVE_CHAT_ITEM_ID) {
-      chatItems.removeLastAndNotify()
+      withApi {
+        withChats {
+          chatItems.removeLastAndNotify()
+        }
+      }
     }
   }
 
@@ -891,19 +898,25 @@ object ChatModel {
 
   fun replaceConnReqView(id: String, withId: String) {
     if (id == showingInvitation.value?.connId) {
-      showingInvitation.value = null
-      chatModel.chatItems.clearAndNotify()
-      chatModel.chatId.value = withId
+      withApi {
+        withChats {
+          showingInvitation.value = null
+          chatItems.clearAndNotify()
+          chatModel.chatId.value = withId
+        }
+      }
       ModalManager.start.closeModals()
       ModalManager.end.closeModals()
     }
   }
 
-  fun dismissConnReqView(id: String) {
+  fun dismissConnReqView(id: String) = withApi {
     if (id == showingInvitation.value?.connId) {
-      showingInvitation.value = null
-      chatModel.chatItems.clearAndNotify()
-      chatModel.chatId.value = null
+      withChats {
+        showingInvitation.value = null
+        chatItems.clearAndNotify()
+        chatModel.chatId.value = null
+      }
       // Close NewChatView
       ModalManager.start.closeModals()
       ModalManager.center.closeModals()

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/model/SimpleXAPI.kt

@@ -3044,8 +3044,8 @@ object ChatController {
     chatModel.users.addAll(users)
     chatModel.currentUser.value = user
     if (user == null) {
-      chatModel.chatItems.clearAndNotify()
       withChats {
+        chatItems.clearAndNotify()
         chats.clear()
         popChatCollector.clear()
       }

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/ChatItemsLoader.kt

@@ -45,9 +45,9 @@ suspend fun apiLoadMessages(
           addChat(chat)
         }
       }
-      withContext(Dispatchers.Main) {
+      withChats {
         chatModel.chatItemStatuses.clear()
-        chatModel.chatItems.replaceAll(chat.chatItems)
+        chatItems.replaceAll(chat.chatItems)
         chatModel.chatId.value = chat.chatInfo.id
         splits.value = newSplits
         if (chat.chatItems.isNotEmpty()) {
@@ -70,8 +70,8 @@ suspend fun apiLoadMessages(
       )
       val insertAt = (indexInCurrentItems - (wasSize - newItems.size) + trimmedIds.size).coerceAtLeast(0)
       newItems.addAll(insertAt, chat.chatItems)
-      withContext(Dispatchers.Main) {
-        chatModel.chatItems.replaceAll(newItems)
+      withChats {
+        chatItems.replaceAll(newItems)
         splits.value = newSplits
         chatState.moveUnreadAfterItem(oldUnreadSplitIndex, newUnreadSplitIndex, oldItems)
       }
@@ -89,8 +89,8 @@ suspend fun apiLoadMessages(
       val indexToAdd = min(indexInCurrentItems + 1, newItems.size)
       val indexToAddIsLast = indexToAdd == newItems.size
       newItems.addAll(indexToAdd, chat.chatItems)
-      withContext(Dispatchers.Main) {
-        chatModel.chatItems.replaceAll(newItems)
+      withChats {
+        chatItems.replaceAll(newItems)
         splits.value = newSplits
         chatState.moveUnreadAfterItem(splits.value.firstOrNull() ?: newItems.last().id, newItems)
         // loading clear bottom area, updating number of unread items after the newest loaded item
@@ -104,8 +104,8 @@ suspend fun apiLoadMessages(
       val newSplits = removeDuplicatesAndUpperSplits(newItems, chat, splits, visibleItemIndexesNonReversed)
       // currently, items will always be added on top, which is index 0
       newItems.addAll(0, chat.chatItems)
-      withContext(Dispatchers.Main) {
-        chatModel.chatItems.replaceAll(newItems)
+      withChats {
+        chatItems.replaceAll(newItems)
         splits.value = listOf(chat.chatItems.last().id) + newSplits
         unreadAfterItemId.value = chat.chatItems.last().id
         totalAfter.value = navInfo.afterTotal
@@ -119,8 +119,8 @@ suspend fun apiLoadMessages(
       newItems.addAll(oldItems)
       removeDuplicates(newItems, chat)
       newItems.addAll(chat.chatItems)
-      withContext(Dispatchers.Main) {
-        chatModel.chatItems.replaceAll(newItems)
+      withChats {
+        chatItems.replaceAll(newItems)
         unreadAfterNewestLoaded.value = 0
       }
     }

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/ChatView.kt

@@ -550,7 +550,9 @@ fun ChatView(staleChatId: State<String?>, onComposed: suspend (chatId: String) -
           LaunchedEffect(chatInfo.id) {
             onComposed(chatInfo.id)
             ModalManager.end.closeModals()
-            chatModel.chatItems.clearAndNotify()
+            withChats {
+              chatItems.clearAndNotify()
+            }
           }
       }
       is ChatInfo.InvalidJSON -> {
@@ -561,7 +563,9 @@ fun ChatView(staleChatId: State<String?>, onComposed: suspend (chatId: String) -
           LaunchedEffect(chatInfo.id) {
             onComposed(chatInfo.id)
             ModalManager.end.closeModals()
-            chatModel.chatItems.clearAndNotify()
+            withChats {
+              chatItems.clearAndNotify()
+            }
           }
       }
       else -> {}

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/GroupMemberInfoView.kt

@@ -98,8 +98,8 @@ fun GroupMemberInfoView(
               val memberChat = Chat(remoteHostId = rhId, ChatInfo.Direct(memberContact), chatItems = arrayListOf())
               withChats {
                 addChat(memberChat)
-                openLoadedChat(memberChat)
               }
+              openLoadedChat(memberChat)
               closeAll()
               chatModel.setContactNetworkStatus(memberContact, NetworkStatus.Connected())
             }

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chatlist/ChatListNavLinkView.kt

@@ -216,15 +216,19 @@ suspend fun openChat(rhId: Long?, chatInfo: ChatInfo) = openChat(rhId, chatInfo.
 private suspend fun openChat(rhId: Long?, chatType: ChatType, apiId: Long) =
   apiLoadMessages(rhId, chatType, apiId, ChatPagination.Initial(ChatPagination.INITIAL_COUNT), chatModel.chatState)
 
-fun openLoadedChat(chat: Chat) {
-  chatModel.chatItemStatuses.clear()
-  chatModel.chatItems.replaceAll(chat.chatItems)
-  chatModel.chatId.value = chat.chatInfo.id
-  chatModel.chatState.clear()
+suspend fun openLoadedChat(chat: Chat) {
+  withChats {
+    chatModel.chatItemStatuses.clear()
+    chatItems.replaceAll(chat.chatItems)
+    chatModel.chatId.value = chat.chatInfo.id
+    chatModel.chatState.clear()
+  }
 }
 
 suspend fun apiFindMessages(ch: Chat, search: String) {
-  chatModel.chatItems.clearAndNotify()
+  withChats {
+    chatItems.clearAndNotify()
+  }
   apiLoadMessages(ch.remoteHostId, ch.chatInfo.chatType, ch.chatInfo.apiId, pagination = ChatPagination.Last(ChatPagination.INITIAL_COUNT), chatModel.chatState, search = search)
 }
 

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/contacts/ContactListNavView.kt

@@ -21,7 +21,9 @@ fun onRequestAccepted(chat: Chat) {
     if (chatInfo is ChatInfo.Direct) {
         ModalManager.start.closeModals()
         if (chatInfo.contact.sndReady) {
-            openLoadedChat(chat)
+            withApi {
+                openLoadedChat(chat)
+            }
         }
     }
 }

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/database/DatabaseView.kt

@@ -528,9 +528,9 @@ fun deleteChatDatabaseFilesAndState() {
 
   // Clear sensitive data on screen just in case ModalManager will fail to prevent hiding its modals while database encrypts itself
   chatModel.chatId.value = null
-  chatModel.chatItems.clearAndNotify()
   withLongRunningApi {
     withChats {
+      chatItems.clearAndNotify()
       chats.clear()
       popChatCollector.clear()
     }

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/newchat/AddGroupView.kt

@@ -44,7 +44,7 @@ fun AddGroupView(chatModel: ChatModel, rh: RemoteHostInfo?, close: () -> Unit, c
         if (groupInfo != null) {
           withChats {
             updateGroup(rhId = rhId, groupInfo)
-            chatModel.chatItems.clearAndNotify()
+            chatItems.clearAndNotify()
             chatModel.chatItemStatuses.clear()
             chatModel.chatId.value = groupInfo.id
           }

apps/multiplatform/common/src/desktopMain/kotlin/chat/simplex/common/DesktopApp.kt

@@ -14,6 +14,7 @@ import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.window.*
 import chat.simplex.common.model.*
+import chat.simplex.common.model.ChatModel.withChats
 import chat.simplex.common.platform.*
 import chat.simplex.common.ui.theme.DEFAULT_START_MODAL_WIDTH
 import chat.simplex.common.ui.theme.SimpleXTheme
@@ -55,8 +56,12 @@ fun showApp() {
               // Better to not close fullscreen since it can contain passcode
             } else {
               // The last possible cause that can be closed
-              chatModel.chatId.value = null
-              chatModel.chatItems.clearAndNotify()
+              withApi {
+                withChats {
+                  chatModel.chatId.value = null
+                  chatItems.clearAndNotify()
+                }
+              }
             }
             chatModel.activeCall.value?.let {
               withBGApi {