Load attachments for conversation view items using long-lived db connection.

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -4007,7 +4007,9 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
             if (viewItem) {
                 viewItem.previousRow = viewItem.row;
             } else {
-                viewItem = [[ConversationViewItem alloc] initWithTSInteraction:interaction isGroupThread:isGroupThread];
+                viewItem = [[ConversationViewItem alloc] initWithInteraction:interaction
+                                                               isGroupThread:isGroupThread
+                                                                 transaction:transaction];
             }
             viewItem.row = (NSInteger)row;
             [viewItems addObject:viewItem];
@@ -4125,7 +4127,7 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
         if (!interaction) {
             OWSFail(@"%@ could not reload interaction", self.logTag);
         } else {
-            [viewItem replaceInteraction:interaction];
+            [viewItem replaceInteraction:interaction transaction:transaction];
         }
     }];
 }

Signal/src/ViewControllers/ConversationView/ConversationViewItem.h

@@ -30,6 +30,7 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType);
 @class TSAttachmentPointer;
 @class TSAttachmentStream;
 @class TSInteraction;
+@class YapDatabaseReadTransaction;
 
 // This is a ViewModel for cells in the conversation view.
 //
@@ -55,15 +56,15 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType);
 // previous update.
 @property (nonatomic) NSInteger previousRow;
 
-//@property (nonatomic, weak) ConversationViewCell *lastCell;
-
 - (instancetype)init NS_UNAVAILABLE;
-- (instancetype)initWithTSInteraction:(TSInteraction *)interaction isGroupThread:(BOOL)isGroupThread;
+- (instancetype)initWithInteraction:(TSInteraction *)interaction
+                      isGroupThread:(BOOL)isGroupThread
+                        transaction:(YapDatabaseReadTransaction *)transaction;
 
 - (ConversationViewCell *)dequeueCellForCollectionView:(UICollectionView *)collectionView
                                              indexPath:(NSIndexPath *)indexPath;
 
-- (void)replaceInteraction:(TSInteraction *)interaction;
+- (void)replaceInteraction:(TSInteraction *)interaction transaction:(YapDatabaseReadTransaction *)transaction;
 
 - (void)clearCachedLayoutState;
 

Signal/src/ViewControllers/ConversationView/ConversationViewItem.m

@@ -63,7 +63,9 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
 
 @implementation ConversationViewItem
 
-- (instancetype)initWithTSInteraction:(TSInteraction *)interaction isGroupThread:(BOOL)isGroupThread
+- (instancetype)initWithInteraction:(TSInteraction *)interaction
+                      isGroupThread:(BOOL)isGroupThread
+                        transaction:(YapDatabaseReadTransaction *)transaction
 {
     self = [super init];
 
@@ -76,10 +78,12 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
     self.row = NSNotFound;
     self.previousRow = NSNotFound;
 
+    [self ensureViewState:transaction];
+
     return self;
 }
 
-- (void)replaceInteraction:(TSInteraction *)interaction
+- (void)replaceInteraction:(TSInteraction *)interaction transaction:(YapDatabaseReadTransaction *)transaction
 {
     OWSAssert(interaction);
 
@@ -93,6 +97,8 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
     self.contentSize = CGSizeZero;
 
     [self clearCachedLayoutState];
+
+    [self ensureViewState:transaction];
 }
 
 - (void)setShouldShowDate:(BOOL)shouldShowDate
@@ -332,7 +338,10 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
 }
 
 - (nullable TSAttachment *)firstAttachmentIfAnyOfMessage:(TSMessage *)message
+                                             transaction:(YapDatabaseReadTransaction *)transaction
 {
+    OWSAssert(transaction);
+
     if (message.attachmentIds.count == 0) {
         return nil;
     }
@@ -340,21 +349,22 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
     if (attachmentId.length == 0) {
         return nil;
     }
-    return [TSAttachment fetchObjectWithUniqueID:attachmentId];
+    return [TSAttachment fetchObjectWithUniqueID:attachmentId transaction:transaction];
 }
 
-- (void)ensureViewState
+- (void)ensureViewState:(YapDatabaseReadTransaction *)transaction
 {
+    OWSAssert([NSThread isMainThread]);
+    OWSAssert(transaction);
+    OWSAssert(!self.hasViewState);
+
     OWSAssert([self.interaction isKindOfClass:[TSOutgoingMessage class]] ||
         [self.interaction isKindOfClass:[TSIncomingMessage class]]);
 
-    if (self.hasViewState) {
-        return;
-    }
     self.hasViewState = YES;
 
     TSMessage *message = (TSMessage *)self.interaction;
-    TSAttachment *_Nullable attachment = [self firstAttachmentIfAnyOfMessage:message];
+    TSAttachment *_Nullable attachment = [self firstAttachmentIfAnyOfMessage:message transaction:transaction];
     if (attachment) {
         if ([attachment isKindOfClass:[TSAttachmentStream class]]) {
             self.attachmentStream = (TSAttachmentStream *)attachment;
@@ -418,16 +428,13 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
 {
     OWSAssert([NSThread isMainThread]);
 
-    [self ensureViewState];
-
     return _messageCellType;
 }
 
 - (nullable DisplayableText *)displayableText
 {
     OWSAssert([NSThread isMainThread]);
-
-    [self ensureViewState];
+    OWSAssert(self.hasViewState);
 
     OWSAssert(_displayableText);
     OWSAssert(_displayableText.displayText);
@@ -439,8 +446,7 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
 - (nullable TSAttachmentStream *)attachmentStream
 {
     OWSAssert([NSThread isMainThread]);
-
-    [self ensureViewState];
+    OWSAssert(self.hasViewState);
 
     return _attachmentStream;
 }
@@ -448,8 +454,7 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
 - (nullable TSAttachmentPointer *)attachmentPointer
 {
     OWSAssert([NSThread isMainThread]);
-
-    [self ensureViewState];
+    OWSAssert(self.hasViewState);
 
     return _attachmentPointer;
 }
@@ -457,8 +462,7 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
 - (CGSize)contentSize
 {
     OWSAssert([NSThread isMainThread]);
-
-    [self ensureViewState];
+    OWSAssert(self.hasViewState);
 
     return _contentSize;
 }

Signal/test/ViewControllers/ConversationViewItemTest.m

@@ -48,7 +48,10 @@
     TSOutgoingMessage *message =
         [[TSOutgoingMessage alloc] initWithTimestamp:1 inThread:nil messageBody:self.fakeTextMessageText];
     [message save];
-    ConversationViewItem *viewItem = [[ConversationViewItem alloc] initWithTSInteraction:message isGroupThread:NO];
+    __block ConversationViewItem *viewItem = nil;
+    [TSYapDatabaseObject.dbReadConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
+        viewItem = [[ConversationViewItem alloc] initWithInteraction:message isGroupThread:NO transaction:transaction];
+    }];
     return viewItem;
 }
 
@@ -72,7 +75,7 @@
     TSOutgoingMessage *message =
         [[TSOutgoingMessage alloc] initWithTimestamp:1 inThread:nil messageBody:nil attachmentIds:attachmentIds];
     [message save];
-    ConversationViewItem *viewItem = [[ConversationViewItem alloc] initWithTSInteraction:message isGroupThread:NO];
+    ConversationViewItem *viewItem = [[ConversationViewItem alloc] initWithInteraction:message isGroupThread:NO];
     return viewItem;
 }