Avoid unnecessary conversation screen updates

Session.xcodeproj/project.pbxproj

@@ -169,6 +169,7 @@
 		B8269D2925C7A4B400488AB4 /* InputView.swift in Sources */ = {isa = PBXBuildFile; fileRef = B8269D2825C7A4B400488AB4 /* InputView.swift */; };
 		B8269D3325C7A8C600488AB4 /* InputViewButton.swift in Sources */ = {isa = PBXBuildFile; fileRef = B8269D3225C7A8C600488AB4 /* InputViewButton.swift */; };
 		B8269D3D25C7B34D00488AB4 /* InputTextView.swift in Sources */ = {isa = PBXBuildFile; fileRef = B8269D3C25C7B34D00488AB4 /* InputTextView.swift */; };
+		B82A0C3826B9098200C1BCE3 /* MessageInvalidator.swift in Sources */ = {isa = PBXBuildFile; fileRef = B82A0C3726B9098200C1BCE3 /* MessageInvalidator.swift */; };
 		B82B40882399EB0E00A248E7 /* LandingVC.swift in Sources */ = {isa = PBXBuildFile; fileRef = B82B40872399EB0E00A248E7 /* LandingVC.swift */; };
 		B82B408A2399EC0600A248E7 /* FakeChatView.swift in Sources */ = {isa = PBXBuildFile; fileRef = B82B40892399EC0600A248E7 /* FakeChatView.swift */; };
 		B82B408C239A068800A248E7 /* RegisterVC.swift in Sources */ = {isa = PBXBuildFile; fileRef = B82B408B239A068800A248E7 /* RegisterVC.swift */; };
@@ -1149,6 +1150,7 @@
 		B8269D2825C7A4B400488AB4 /* InputView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = InputView.swift; sourceTree = "<group>"; };
 		B8269D3225C7A8C600488AB4 /* InputViewButton.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = InputViewButton.swift; sourceTree = "<group>"; };
 		B8269D3C25C7B34D00488AB4 /* InputTextView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = InputTextView.swift; sourceTree = "<group>"; };
+		B82A0C3726B9098200C1BCE3 /* MessageInvalidator.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MessageInvalidator.swift; sourceTree = "<group>"; };
 		B82B40872399EB0E00A248E7 /* LandingVC.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LandingVC.swift; sourceTree = "<group>"; };
 		B82B40892399EC0600A248E7 /* FakeChatView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FakeChatView.swift; sourceTree = "<group>"; };
 		B82B408B239A068800A248E7 /* RegisterVC.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RegisterVC.swift; sourceTree = "<group>"; };
@@ -3115,6 +3117,7 @@
 				C33FDBC1255A581700E217F9 /* General.swift */,
 				B8AE760925ABFB00001A84D2 /* GeneralUtilities.h */,
 				B8AE760A25ABFB5A001A84D2 /* GeneralUtilities.m */,
+				B82A0C3726B9098200C1BCE3 /* MessageInvalidator.swift */,
 				C3A71D0A2558989C0043A11F /* MessageWrapper.swift */,
 				C3A71D4E25589FF30043A11F /* NSData+messagePadding.h */,
 				C3A71D4825589FF20043A11F /* NSData+messagePadding.m */,
@@ -4746,6 +4749,7 @@
 				C32C5C01256DC9A0003C73A2 /* OWSIdentityManager.m in Sources */,
 				C32C59C4256DB41F003C73A2 /* TSContactThread.m in Sources */,
 				C32C5AB0256DBE8F003C73A2 /* TSOutgoingMessage.m in Sources */,
+				B82A0C3826B9098200C1BCE3 /* MessageInvalidator.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Session/Conversations/ConversationVC.swift

@@ -368,9 +368,9 @@ final class ConversationVC : BaseVC, ConversationViewModelDelegate, OWSConversat
                         shouldScrollToBottom = self.isCloseToBottom
                     }
                 case .update:
-                    // FIXME: This is called many times when a message is inserted, leading to bad performance
+                    shouldScrollToBottom = self.isCloseToBottom // Check this * before * reloading the row
+                    print("[Test] UPDATE")
                     self.messagesTableView.reloadRows(at: [ IndexPath(row: Int(update.oldIndex), section: 0) ], with: .none)
-                    shouldScrollToBottom = self.isCloseToBottom
                 default: preconditionFailure()
                 }
             }

Session/Conversations/ConversationViewModel.m

@@ -822,9 +822,13 @@ NS_ASSUME_NONNULL_BEGIN
             OWSFailDebug(@"Can't find holdover view item.");
             return [self.delegate conversationViewModelDidUpdate:ConversationUpdate.reloadUpdate];
         }
-        if (!viewItem.hasCachedLayoutState) {
-            [updatedItemSet addObject:itemId];
-            [updatedNeighborItemSet addObject:itemId];
+        
+        if ([viewItem.interaction isKindOfClass:TSMessage.class]) {
+            TSMessage *message = (TSMessage *)viewItem.interaction;
+            if ([MessageInvalidator isInvalidated:message]) {
+                [updatedItemSet addObject:itemId];
+                [updatedNeighborItemSet addObject:itemId];
+            }
         }
     }
 
@@ -864,6 +868,10 @@ NS_ASSUME_NONNULL_BEGIN
                                               oldViewItemCount:oldItemIdList.count
                                         updatedNeighborItemSet:updatedNeighborItemSet];
 
+    for (NSString *itemID in updatedItemSet) {
+        [MessageInvalidator markAsUpdated:itemID];
+    }
+    
     return [self.delegate
         conversationViewModelDidUpdate:[ConversationUpdate diffUpdateWithUpdateItems:updateItems
                                                                 shouldAnimateUpdates:shouldAnimateUpdates]];

Session/Conversations/Settings/OWSConversationSettingsViewController.m

@@ -1002,7 +1002,7 @@ CGFloat kIconViewLength = 24;
     UISwitch *uiSwitch = (UISwitch *)sender;
     BOOL isEnabled = uiSwitch.isOn;
     [LKStorage writeWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
-        [(TSGroupThread *)self.thread setisOnlyNotifyingForMentions:isEnabled withTransaction:transaction];
+        [(TSGroupThread *)self.thread setIsOnlyNotifyingForMentions:isEnabled withTransaction:transaction];
     }];
 }
 

Session/Conversations/Views & Modals/DownloadAttachmentModal.swift

@@ -70,7 +70,7 @@ final class DownloadAttachmentModal : Modal {
         contact.isTrusted = true
         Storage.write(with: { transaction in
             Storage.shared.setContact(contact, using: transaction)
-            message.touch(with: transaction)
+            MessageInvalidator.invalidate(message, with: transaction)
         }, completion: {
             Storage.shared.resumeAttachmentDownloadJobsIfNeeded(for: message.uniqueThreadId)
         })

SessionMessagingKit/Database/Storage+Messaging.swift

@@ -67,7 +67,7 @@ extension Storage {
         pointer.state = state
         pointer.save(with: transaction)
         guard let tsMessage = TSMessage.fetch(uniqueId: tsMessageID, transaction: transaction) else { return }
-        tsMessage.touch(with: transaction)
+        MessageInvalidator.invalidate(tsMessage, with: transaction)
     }
     
     /// Also touches the associated message.
@@ -75,7 +75,7 @@ extension Storage {
         let transaction = transaction as! YapDatabaseReadWriteTransaction
         stream.save(with: transaction)
         guard let tsMessage = TSMessage.fetch(uniqueId: tsMessageID, transaction: transaction) else { return }
-        tsMessage.touch(with: transaction)
+        MessageInvalidator.invalidate(tsMessage, with: transaction)
     }
 
     private static let receivedMessageTimestampsCollection = "ReceivedMessageTimestampsCollection"

SessionMessagingKit/Jobs/AttachmentUploadJob.swift

@@ -118,12 +118,14 @@ public final class AttachmentUploadJob : NSObject, Job, NSCoding { // NSObject/N
         delegate?.handleJobSucceeded(self)
         SNMessagingKitConfiguration.shared.storage.resumeMessageSendJobIfNeeded(messageSendJobID)
         Storage.shared.write(with: { transaction in
-            var interaction: TSInteraction?
+            var message: TSMessage?
             let transaction = transaction as! YapDatabaseReadWriteTransaction
             TSDatabaseSecondaryIndexes.enumerateMessages(withTimestamp: self.message.sentTimestamp!, with: { _, key, _ in
-                interaction = TSInteraction.fetch(uniqueId: key, transaction: transaction)
+                message = TSMessage.fetch(uniqueId: key, transaction: transaction)
             }, using: transaction)
-            interaction?.touch(with: transaction) // To refresh the associated message cell and hide the loader
+            if let message = message {
+                MessageInvalidator.invalidate(message, with: transaction)
+            }
         }, completion: { })
     }
     

SessionMessagingKit/Sending & Receiving/MessageSender.swift

@@ -340,6 +340,7 @@ public final class MessageSender : NSObject {
             recipients.forEach { recipient in
                 tsMessage.update(withSentRecipient: recipient, wasSentByUD: true, transaction: transaction)
             }
+            MessageInvalidator.invalidate(tsMessage, with: transaction)
             // Start the disappearing messages timer if needed
             OWSDisappearingMessagesJob.shared().startAnyExpiration(for: tsMessage, expirationStartedAt: NSDate.millisecondTimestamp(), transaction: transaction)
         }

SessionMessagingKit/Threads/TSGroupThread.h

@@ -45,7 +45,7 @@ extern NSString *const TSGroupThread_NotificationKey_UniqueId;
                                               transaction:(YapDatabaseReadWriteTransaction *)transaction;
 
 - (void)setGroupModel:(TSGroupModel *)newGroupModel withTransaction:(YapDatabaseReadWriteTransaction *)transaction;
-- (void)setisOnlyNotifyingForMentions:(BOOL)isOnlyNotifyingForMentions withTransaction:(YapDatabaseReadWriteTransaction *)transaction;
+- (void)setIsOnlyNotifyingForMentions:(BOOL)isOnlyNotifyingForMentions withTransaction:(YapDatabaseReadWriteTransaction *)transaction;
 - (void)leaveGroupWithSneakyTransaction;
 - (void)leaveGroupWithTransaction:(YapDatabaseReadWriteTransaction *)transaction;
 

SessionMessagingKit/Threads/TSGroupThread.m

@@ -208,7 +208,7 @@ NSString *const TSGroupThread_NotificationKey_UniqueId = @"TSGroupThread_Notific
     }];
 }
 
-- (void)setisOnlyNotifyingForMentions:(BOOL)isOnlyNotifyingForMentions withTransaction:(YapDatabaseReadWriteTransaction *)transaction
+- (void)setIsOnlyNotifyingForMentions:(BOOL)isOnlyNotifyingForMentions withTransaction:(YapDatabaseReadWriteTransaction *)transaction
 {
     self.isOnlyNotifyingForMentions = isOnlyNotifyingForMentions;
     

SessionMessagingKit/Utilities/MessageInvalidator.swift

@@ -0,0 +1,27 @@
+
+/// A message is invalidated when it needs to be re-rendered in the UI. Examples of when this happens include:
+///
+/// • When the sent or read status of a message is updated.
+/// • When an attachment is uploaded or downloaded.
+@objc public final class MessageInvalidator : NSObject {
+    private static var invalidatedMessages: Set<String> = []
+    
+    @objc public static let shared = MessageInvalidator()
+    
+    private override init() { }
+    
+    @objc public static func invalidate(_ message: TSMessage, with transaction: YapDatabaseReadWriteTransaction) {
+        guard let id = message.uniqueId else { return }
+        invalidatedMessages.insert(id)
+        message.touch(with: transaction)
+    }
+    
+    @objc public static func isInvalidated(_ message: TSMessage) -> Bool {
+        guard let id = message.uniqueId else { return false }
+        return invalidatedMessages.contains(id)
+    }
+    
+    @objc public static func markAsUpdated(_ id: String) {
+        invalidatedMessages.remove(id)
+    }
+}